WorldWideScience

Sample records for blood vessel prosthesis implantation

  1. [Flap repair for vascular prosthesis exposure after artificial blood vessel bypass surgery for critical limb ischemia].

    Science.gov (United States)

    Wu, Wei-wei; Wu, Hao; Zeng, Ang; Bai, Ming; Zeng, Rong; Chen, Yu; Liu, Chang-wei

    2013-08-01

    To investigate the effectiveness of flap repair for vascular prosthesis exposure after the artificial blood vessel bypass surgery for critical limb ischemia. From August 2007 to December 2011, bypass surgery with vascular prosthetic grafts were performed in 192 patients with critical limb ischemia.Five patients among them (2.6%) suffered from vascular prosthesis exposure 6 to 13 days after the previous surgery, including 4 males and 1 female, with a median age of 68 years(arranged from 52 to 81 years). The surgical managements included surgical debridement and local flap or transferred muscle-cutaneous flap repair to preserve the prosthetic vascular grafts. Three patients underwent Z-plasty with local flap repair, while 2 patients underwent transferred rectus abdominis or rectus femoris muscle flap repair of the wounds. After the surgery, prosthetic vascular graft was successfully preserved in 4 of the 5 cases with first intention healing. At a median follow-up of 38 months (arranged from 5 to 57 months), all the 4 limbs were salvaged with patent of the prosthetic grafts.One flap failed to heal and the prosthetic graft had to be removed due to infection and hemorrhage. An above-knee-amputation was performed due to severe limb ischemia. The vascular prosthesis exposure is often a disaster after artificial blood vessel bypass surgery for critical limb ischemia.Local flap or transferred muscle-cutaneous flap repair is an effective surgical management to salvage the exposed graft and the affected limb.

  2. An artificial blood vessel implanted three-dimensional microsystem for modeling transvascular migration of tumor cells.

    Science.gov (United States)

    Wang, Xue-Ying; Pei, Ying; Xie, Min; Jin, Zi-He; Xiao, Ya-Shi; Wang, Yang; Zhang, Li-Na; Li, Yan; Huang, Wei-Hua

    2015-02-21

    Reproducing a tumor microenvironment consisting of blood vessels and tumor cells for modeling tumor invasion in vitro is particularly challenging. Here, we report an artificial blood vessel implanted 3D microfluidic system for reproducing transvascular migration of tumor cells. The transparent, porous and elastic artificial blood vessels are obtained by constructing polysaccharide cellulose-based microtubes using a chitosan sacrificial template, and possess excellent cytocompatibility, permeability, and mechanical characteristics. The artificial blood vessels are then fully implanted into the collagen matrix to reconstruct the 3D microsystem for modeling transvascular migration of tumor cells. Well-defined simulated vascular lumens were obtained by proliferation of the human umbilical vein endothelial cells (HUVECs) lining the artificial blood vessels, which enables us to reproduce structures and functions of blood vessels and replicate various hemodynamic parameters. Based on this model, the adhesion and transvascular migration of tumor cells across the artificial blood vessel have been well reproduced.

  3. Penile Prosthesis Implantation in Priapism.

    Science.gov (United States)

    Yücel, Ömer Barış; Pazır, Yaşar; Kadıoğlu, Ateş

    2018-04-01

    Priapism is defined as a full or partial erection lasting longer than 4 hours after sexual stimulation and orgasm or unrelated to sexual stimulation. The main goal of priapism management is to resolve the episode immediately to preserve erectile function and penile length. Corporal smooth muscle necrosis is likely to have already occurred, and medically refractory erectile dysfunction is expected in patients with a protracted episode. Penile prosthesis implantation (PPI) in the early or late phase of priapism can restore erectile function. To review the literature on PPI in priapism. A PubMed search of all English-language articles published before 2017 was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement using the following search terms: penile prosthesis implantation, priapism, and corporal fibrosis. All publications reporting on PPI during or after priapism episodes were included for review. Three types of priapism were reviewed for management using PPI. Surgical techniques, outcomes, and patient satisfaction were reported. Early implantation (during the episode) is technically easier and has lower complication rates compared with delayed (electively, after the erectile dysfunction is observed) surgery. Immediate PPI also allows preservation of penile length, which is related to higher satisfaction rates. The paradigm is shifting toward immediate PPI in the management of ischemic priapism. Patients with non-ischemic priapism or recurrent priapism, even without a major ischemic episode, are at high risk for erectile dysfunction and are candidates for PPI. Yücel ÖB, Pazır Y, Kadıoğlu A. Penile Prosthesis Implantation in Priapism. Sex Med Rev 2018;6:310-318. Copyright © 2017. Published by Elsevier Inc.

  4. Glans Necrosis Following Penile Prosthesis Implantation: Prevention and Treatment Suggestions.

    Science.gov (United States)

    Wilson, Steven K; Mora-Estaves, Cesar; Egydio, Paulo; Ralph, David; Habous, Mohamad; Love, Christopher; Shamsodini, Ahmad; Valenzuela, Robert; Yafi, Faysal A

    2017-09-01

    To examine possible etiology and treatment outcomes in 21 patients with glans necrosis following penile prosthesis implantation. Glans necrosis typically presented with a dusky glans on the first postoperative day following prosthesis implantation. The blood supply to the glans penis consists of the dorsal arteries and the terminal branches of the spongiosal arteries. Using the cohort in our study, we compiled preoperative comorbidities and adjunctive surgical maneuvers that might compromise glans vascularity, leading to glans necrosis. Preoperative risk factors were arteriosclerotic cardiovascular disease (90%), diabetes mellitus (81%), smoking (81%), previous prosthesis explantation (57%), and previous radiation therapy (48%). The most prevalent intraoperative and postoperative factor was subcoronal incision for reasons as simple as coincident circumcision or as complex as for penile degloving (86%). Other factors detected were penile wrapping with an occlusive elastic bandage (62%), use of a sliding technique for penile lengthening (33%), and coincident distal urethral injury repair (29%). Seventeen patients (81%) managed expectantly with preservation of implanted prosthesis sustained significant glandular loss. Four patients managed with immediate prosthesis removal healed without sequelae. Patients with preoperative risk factors undergoing penile prosthesis implantation should avoid high-risk adjunctive surgical maneuvers. Upon development of signs of glans necrosis postoperatively, in the setting of these high-risk factors, immediate implant removal may prevent subsequent glans necrosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Investigation of source-detector separation optimization for an implantable perfusion and oxygenation sensor for liver blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S [ORNL; Akl, Tony [Texas A& M University; Cote, Gerard L. [Texas A& M University; Wilson, Mark A. [University of Pittsburgh School of Medicine, Pittsburgh PA; Ericson, Milton Nance [ORNL

    2011-01-01

    An implanted system is being developed to monitor transplanted liver health during the critical 7-10 day period posttransplantation. The unit will monitor organ perfusion and oxygen consumption using optically-based probes placed on both the inflow and outflow blood vessels, and on the liver parenchymal surface. Sensing probes are based on a 3- wavelength LED source and a photodiode detector. Sample diffuse reflectance is measured at 735, 805, and 940 nm. To ascertain optimal source-to-photodetector spacing for perfusion measurement in blood vessels, an ex vivo study was conducted. In this work, a dye mixture simulating 80% blood oxygen saturation was developed and perfused through excised porcine arteries while collecting data for various preset probe source-to-photodetector spacings. The results from this study demonstrate a decrease in the optical signal with decreasing LED drive current and a reduction in perfusion index signal with increasing probe spacing. They also reveal a 2- to 4-mm optimal range for blood vessel perfusion probe source-to-photodetector spacing that allows for sufficient perfusion signal modulation depth with maximized signal to noise ratio (SNR). These findings are currently being applied to guide electronic configuration and probe placement for in vivo liver perfusion porcine model studies.

  6. Implant-Retained Auricular Prosthesis: A Case Report

    OpenAIRE

    Ozturk, A. Nilgun; Usumez, Aslihan; Tosun, Zekeriya

    2010-01-01

    Extraoral implant retained prosthesis have been proven to be a predictable treatment option for maxillofacial rehabilitation. This case report describes the clinical and laboratory procedures for fabricating an auricular prosthesis. In this case report, an auricular prosthesis was fabricated for a patient who lost the left and right external ear in an electrical burn. Extraoral implants and bar-and-clip retention for the proper connection of the auricular prosthesis to implant were used. This...

  7. Mandrels For Microtextured Small-Vessel Implants

    Science.gov (United States)

    Deininger, William D.; Gabriel, Stephen B.

    1989-01-01

    Research shows artificial blood-vessel and heart-valve implants made more compatible with their biological environments by use of regularly microtextured surfaces. In new manufacturing process, ion beam etches patterned array of small pillars on mandrel used to mold tubular plastic implant. Pillars create tiny regularly spaced holes in inner surface of tube. Holes expected to provide sites for attachment of healthy lining. Polytetrafluoroethylene (PTFE) used as mandrel material because it can be etched by ion beam.

  8. Interim Prosthesis Options for Dental Implants.

    Science.gov (United States)

    Siadat, Hakimeh; Alikhasi, Marzieh; Beyabanaki, Elaheh

    2017-06-01

    Dental implants have become a popular treatment modality for replacing missing teeth. In this regard, the importance of restoring patients with function during the implant healing period has grown in recent decades. Esthetic concerns, especially in the anterior region of the maxilla, should also be considered until the definitive restoration is delivered. Another indication for such restorations is maintenance of the space required for esthetic and functional definitive restorations in cases where the implant site is surrounded by natural teeth. Numerous articles have described different types of interim prostheses and their fabrication techniques. This article aims to briefly discuss all types of implant-related interim prostheses by different classification including provisional timing (before implant placement, after implant placement in unloading and loading periods), materials, and techniques used for making the restorations, the type of interim prosthesis retention, and definitive restoration. Furthermore, the abutment torque for such restorations and methods for transferring the soft tissue from interim to definitive prostheses are addressed. © 2015 by the American College of Prosthodontists.

  9. 21 CFR 872.3970 - Interarticular disc prosthesis (interpositional implant).

    Science.gov (United States)

    2010-04-01

    ... implant). 872.3970 Section 872.3970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3970 Interarticular disc prosthesis (interpositional implant). (a) Identification. An interarticular disc prosthesis...

  10. Penile Prosthesis Implantation in Acute and Chronic Priapism.

    Science.gov (United States)

    Garaffa, Giulio; Ralph, David J

    2013-07-01

    To review the current literature regarding penile prosthesis implantation in acute and chronic priapism. A nonstructured Pubmed base search using the terms ischemic priapism, penile prosthesis, and refractory erectile dysfunction has been carried out. Surgical outcome and patient satisfaction following penile prosthesis implantation are reported. Implantation of a penile prosthesis in acute and chronic ischemic priapism is associated with increased complication rates, when compared with virgin implants. Implantation in acute priapism allows the painful priapic episode to settle and to preserve penile length, while implantation in chronic priapism is technically much more challenging and often requires the use of downsized shorter cylinders. Implantation of a penile prosthesis in acute refractory ischemic priapism should be the solution of choice, as the dilatation is easier and allows the preservation of penile length, which is one of the main factors influencing postoperative patient's satisfaction in prosthetic surgery. Garaffa G and Ralph D. Penile prosthesis implantation in acute and chronic priapism. Sex Med Rev 2013;1:76-82. Copyright © 2013 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  11. Paving the Way for Implant Placement for an Auricular Prosthesis

    Directory of Open Access Journals (Sweden)

    Dipti S Shah

    2013-01-01

    Full Text Available Background: Ideal placement of bone integrated implants to retain a prosthesis is critical for a successful final prosthetic restoration. Several sources have described the importance and use of surgical templates for the optimal placement of extraoral implants. The literature is replete with information explaining the use of surgic al templates for intraoral implant placement. Indeed, correct placement of implants facilitates creating a prosthesis that functions well and looks natural. To ensure proper implant placement, considerable effort should go into pre-surgical planning. It is clear that extraoral surgical templates aid in proper implant placement, yet the literature describing fabrication is limited. This article describes different methods for fabrication of surgical template for placement of implants for an auricular prosthesis.

  12. Distal corporoplasty for distal cylinders extrusion after penile prosthesis implantation.

    Science.gov (United States)

    Carrino, Maurizio; Chiancone, Francesco; Battaglia, Gaetano; Pucci, Luigi; Fedelini, Paolo

    2017-02-03

    Distal extrusion of cylinders is a potential complication of the penile prosthesis implantation. Several methods have been proposed for repairing a distal penile erosion. We present our preliminary experience in "Distal corporoplasty" technique. We enrolled 18 consecutive patients whose underwent a distal corporoplasty with simultaneous reimplantation of an "AMS 700 inflatable penile prosthesis (LGX)" from January 2013 to November 2015 at our hospital. All procedures were performed by a single surgical team. Intraoperative and postoperative complications have been classified and reported according to Satava6 and Clavien-Dindo (CD) system.7 Mean values with standard deviations (±SD) were computed and reported for all items. Mean age of the patients was 53.61 (±11.90) years. Mean body max index (BMI) was 24.22 (±2.51). Mean operative time was 85.2 (±13.1) minutes. Blood losses were minimal. No intraoperative complications are reported according to Satava classification. Four out of 18 patients (22.22%) experienced postoperative complications according to CD system. All patients had sexual intercourse for the first time postsurgery after a mean of 59.11 ± 2.08 days. Mean follow-up was 22.11 (±9.95). Distal extrusion of cylinders is a potential complication of the penile prosthesis implantation. Distal corporoplasty was first described by Mulcahy. He reported a series of 14 patients with a follow-up of about 2 years with optimal functional outcomes. Moreover, distal corporoplasty resulted in shorter operative time, better function, less pain, and fewer recurrences than Gortex windsock repair.10 In our experience, distal corporoplasty is a simple and safe procedure in the treatment of distal cylinders extrusion when the prosthetic material is not exposed to the exterior.

  13. Split-Framework in Mandibular Implant-Supported Prosthesis

    Directory of Open Access Journals (Sweden)

    Danny Omar Mendoza Marin

    2015-01-01

    Full Text Available During oral rehabilitation of an edentulous patient with an implant-supported prosthesis, mandibular flexure must be considered an important biomechanical factor when planning the metal framework design, especially if implants are installed posterior to the interforaminal region. When an edentulous mandible is restored with a fixed implant-supported prosthesis connected by a fixed full-arch framework, mandibular flexure may cause needless stress in the overall restorative system and lead to screw loosening, poor fit of prosthesis, loss of the posterior implant, and patient’s discomfort due to deformation properties of the mandible during functional movements. The use of a split-framework could decrease the stress with a precise and passive fit on the implants and restore a more natural functional condition of the mandible, helping in the longevity of the prosthesis. Therefore, the present clinical report describes the oral rehabilitation of an edentulous patient by a mandibular fixed implant-supported prosthesis with a split-framework to compensate for mandibular flexure. Clinical Significance. The present clinical report shows that the use of a split-framework reduced the risk of loss of the posterior implants or screws loosening with acceptable patient comfort over the period of a year. The split-framework might have compensated for the mandibular flexure during functional activities.

  14. 21 CFR 874.3695 - Mandibular implant facial prosthesis.

    Science.gov (United States)

    2010-04-01

    ... made of materials such as stainless steel, tantalum, titanium, cobalt-chromium based alloy... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mandibular implant facial prosthesis. 874.3695... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3695 Mandibular implant...

  15. Mastication improvement after partial implant-supported prosthesis use.

    Science.gov (United States)

    Gonçalves, T M S V; Campos, C H; Gonçalves, G M; de Moraes, M; Rodrigues Garcia, R C M

    2013-12-01

    Partially edentulous patients may be rehabilitated by the placement of removable dental prostheses, implant-supported removable dental prostheses, or partial implant fixed dental prostheses. However, it is unclear the impact of each prosthesis type over the masticatory aspects, which represents the objective of this paired clinical trial. Twelve patients sequentially received and used each of these 3 prosthesis types for 2 months, after which maximum bite force was assessed by a strain sensor and food comminution index was determined with the sieving method. Masseter and temporal muscle thicknesses during rest and maximal clenching were also evaluated by ultrasonography. Each maxillary arch received a new complete denture that was used throughout the study. Data were analyzed by analysis of variance for repeated measures, followed by the Tukey test (p dental prosthesis and implant fixed dental prosthesis use, with the higher improvement found after the latter's use. Regardless of implant-retained prosthesis type, masseter muscle thickness during maximal clenching also increased (p prosthesis type.

  16. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Stepanov, R.P.

    1985-01-01

    Data on phenomenology of radiation-induced changes in blood vessels are systematized and authors' experience is generalized. Modern concepts about processes leading to vessel structure injury after irradiation is critically analyzed. Special attention is paid to reparation and compensation of X-ray vessel injury, consideration of which is not yet sufficiently elucidated in literature

  17. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Stepanov, R.P.

    1985-01-01

    Data on phenomeology of radiation changes of blood vessels are systemized and the authors' experience is generalyzed. A critical analysis of modern conceptions on processes resulting in vessel structure damage after irradiation, is given. Special attention is paid to reparation and compensation of radiation injury of vessels

  18. Amputation and prosthesis implantation shape body and peripersonal space representations.

    Science.gov (United States)

    Canzoneri, Elisa; Marzolla, Marilena; Amoresano, Amedeo; Verni, Gennaro; Serino, Andrea

    2013-10-03

    Little is known about whether and how multimodal representations of the body (BRs) and of the space around the body (Peripersonal Space, PPS) adapt to amputation and prosthesis implantation. In order to investigate this issue, we tested BR in a group of upper limb amputees by means of a tactile distance perception task and PPS by means of an audio-tactile interaction task. Subjects performed the tasks with stimulation either on the healthy limb or the stump of the amputated limb, while wearing or not wearing their prosthesis. When patients performed the tasks on the amputated limb, without the prosthesis, the perception of arm length shrank, with a concurrent shift of PPS boundaries towards the stump. Conversely, wearing the prosthesis increased the perceived length of the stump and extended the PPS boundaries so as to include the prosthetic hand, such that the prosthesis partially replaced the missing limb.

  19. Transcatheter aortic valve prosthesis surgically replaced 4 months after implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Lund, Jens Teglgaard; Engstrøm, Thomas

    2010-01-01

    Transcatheter aortic valve implantation is a new and rapidly evolving treatment option for high-risk surgical patients with degenerative aortic valve stenosis. Long-term results with these new valve prostheses are lacking, and potential valve dysfunction and failure would require valve replacemen....... We report the first case of surgical valve replacement in a patient with a dysfunctional transcatheter-implanted aortic valve prosthesis 4 months after implantation....

  20. Ischemic Gangrene of the Glans following Penile Prosthesis Implantation

    Science.gov (United States)

    García Gómez, Borja; Romero Otero, Javier; Díez Sicilia, Laura; Jiménez Alcaide, Estibaliz; García-Cruz, Eduardo; Rodríguez Antolín, Alfredo

    2013-01-01

    The development of ischemic gangrene of the penis following implantation of prosthesis is unusual, and very few cases are available in the literature. As a result, no established treatment protocol is available. We report our experience within a case of gangrene of the glans following implantation of a three-component prosthesis. We present a 53-year-old male, smoker with diabetes and hypercholesterolemia, who underwent surgery for the insertion of a penile prosthesis with 3 components to correct his erectile dysfunction and severe Peyronie's disease. The procedure was carried out without incidents. During the postoperative period, the patient began to complain from penile and perineal pain. He developed avascular necrosis of the glans. The necrosed area was excised. Four weeks later, he developed fever and perineal pain arriving to the emergency room with the prosthesis extruding through the glans. He had emergency surgery to remove the prosthesis plus surgical lavage and was prescribed broad-spectrum antibiotic therapy. Four weeks later, the penis was completely revascularized and reepithelialized. Ischemic gangrene following penile prosthesis implantation takes place in patients with poor peripheral vascularisation. Diabetes mellitus has been the common denominator to all of the reported cases. PMID:23956919

  1. [Total Elbow Replacement - Implantation of the Latitude Prosthesis (Tornier)].

    Science.gov (United States)

    Hackl, M; Wegmann, K; Leschinger, T; Ries, C; Burkhart, K J; Müller, L

    2015-10-01

    Due to technical progress, the indication for total elbow arthroplasty could be expanded in recent years. As a result, the demand regarding functionality and mobility of the replaced joint has risen as well. Elbow arthroplasty has to be considered as technically demanding. Only with detailed knowledge of this surgical procedure and its possible intraoperative pitfalls can one provide the best possible results. In this instructional video we explain the implantation of the Latitude elbow prosthesis (Tornier) putting emphasis on the correct approach as well as implantation of the prosthesis and subsequent wound closure. Georg Thieme Verlag KG Stuttgart · New York.

  2. Penile prosthesis implantation in the era of medical treatment for erectile dysfunction.

    Science.gov (United States)

    Montague, Drogo K

    2011-05-01

    Penile prosthesis implantation, the oldest of the modern treatments for erectile dysfunction (ED), still plays an important role despite the advent of less invasive alternatives. For some men with ED, penile prosthesis implantation is the only effective or acceptable treatment. Penile prosthesis implantation remains a viable option in the contemporary management of ED as evidenced by annual penile prosthesis implantation cases in the United States rising from 17,540 in 2000 to 22,420 in 2009. Improvements in prosthesis design and implantation techniques have resulted in significant increases in device survival and patient satisfaction. 2011 Elsevier Inc. All rights reserved.

  3. Improved comfort and function of arm prosthesis after implantation of a Humerus-T-Prosthesis in trans-humeral amputees.

    Science.gov (United States)

    Witsø, Eivind; Kristensen, Tomm; Benum, Pål; Sivertsen, Svein; Persen, Leif; Funderud, Are; Magne, Tordis; Aursand, Hans Petter; Aamodt, Arild

    2006-12-01

    The use of arm prosthesis in trans-humeral amputees is limited; due to the cone form of the amputation stump. A Humerus-T-Prosthesis was implanted in three patients to create artificial humerus condyles. Two of the patients were successfully rehabilitated with the application of a new type trans-humeral arm prosthesis. This arm prosthesis had a socket which is suspended and stabilized by the humerus and implant only. Traction and rotational stability were secured by adjustable pressure adaptation around the artificial condyles. The third patient developed a pressure wound over the lateral part of the artificial condyle that later healed. He also was subject to a new trauma with a fracture of the ipsilateral scapula and until now has had limited the use of his new arm prosthesis. It was concluded that this new concept for prosthesis fitting of trans-humeral amputees looks promising, but alternative designs of the implant should be tested.

  4. Blood vessels, circulation and blood pressure.

    Science.gov (United States)

    Hendry, Charles; Farley, Alistair; McLafferty, Ella

    This article, which forms part of the life sciences series, describes the vessels of the body's blood and lymphatic circulatory systems. Blood pressure and its regulatory systems are examined. The causes and management of hypertension are also explored. It is important that nurses and other healthcare professionals understand the various mechanisms involved in the regulation of blood pressure to prevent high blood pressure or ameliorate its damaging consequences.

  5. Immediate placement and loading of implants in anterior maxilla using an altered screw-retained implant fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Baig Mirza

    2010-01-01

    Full Text Available This article describes the immediate placement and loading of implants in the aesthetic zone using an implant-retained, fixed prosthesis with a modified design. One section of the implant prosthesis has cemented crowns and the other section is the conventional screw-retained. This combined approach significantly offsets the unsuitable implant position, alignment or angulation, while ensuring the easy retrievability, repair and maintenance of the prosthesis at the same time.

  6. Heterotopic ossification associated with myelopathy following cervical disc prosthesis implantation.

    Science.gov (United States)

    Wenger, Markus; Markwalder, Thomas-Marc

    2016-04-01

    This case report presents a 37-year-old man with clinical signs of myelopathy almost 9 years after implantation of a Bryan disc prosthesis (Medtronic Sofamor Danek, Memphis, TN, USA) for C5/C6 soft disc herniation. As demonstrated on MRI and CT scan, spinal cord compression was caused by bony spurs due to heterotopic ossification posterior to the still moving prosthesis. The device, as well as the ectopic bone deposits, had to be removed because of myelopathy and its imminent aggravation. Conversion to anterior spondylodesis was performed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Intraoral framework pick-up technique to improve fit of a metal-resin implant prosthesis

    Directory of Open Access Journals (Sweden)

    Mirza Rustum Baig

    2012-01-01

    Full Text Available The achievement of passive fit is an important prerequisite for the prevention of complications in full-arch screw-retained implant prosthesis. With cemented prosthesis, the cementation compensates for the discrepancies in the cast framework, but the lack of retrievability seems undesirable. The aim of this paper is to propose a modified screw-retained prosthesis design for complete arch implant fixed rehabilitation. A technique for the fabrication of a full-arch metal-resin implant-supported screw-retained prosthesis is described. Cementation of the framework to the abutments intraorally improves the passivity of fit of the prosthesis on the implants. Maintenance of screw-access channels in the final prosthesis ensures retrievability. The metal-resin design allows for easy repair and maintenance. The prosthesis is cost-effective compared to conventional options and can be employed as a viable treatment alternative when considering metal-acrylic resin complete arch fixed prosthesis.

  8. Modified cementless total coxofemoral prosthesis: development, implantation and clinical evaluation

    Directory of Open Access Journals (Sweden)

    S.A. Arias

    2013-12-01

    Full Text Available The aim of this study was to modify canine coxofemoral prostheses and the clinical evaluation of the implantation. Fifteen canine hips and femora of cadavers were used in order to study the surface points of modification in prostheses and develop a perforation guide. Femoral stems and acetabular components were perforated and coated with biphasic calcium phosphate layer. Twelve young adult male mongrel dogs were implanted with coxofemoral prostheses. Six were operated upon and implanted with cemented canine modular hip prostheses, establishing the control group. The remaining six were implanted with a novel design of cementless porous tricalcic phosphate-hydroxyapatite coated hip prostheses. Clinical and orthopedic performance, complications, and thigh muscular hypotrophy were assessed up to the 120th post-operatory day. After 120 days, animals with cementless prostheses had similar clinical and orthopedic performance compared to the cemented group despite the increased pain thigh hypotrophy. Animals that underwent cementless hip prosthesis evidenced more pain, compared to animals with cemented hip prosthesis that required longer recuperation time. No luxations, two fractures and two isquiatic neurapraxies were identified in the course of the study. Using both the cemented and the bioactive coated cementless model were suitable to dogs, showing clinical satisfactory results. Osseointegration and biological fixation were observed in the animals with the modified cementless hip prosthesis.

  9. Gait assessment in patients with thrust plate prosthesis and intramedullary stemmed prosthesis implanted to each hip.

    Science.gov (United States)

    Angin, Salih; Karatosun, Vasfi; Unver, Bayram; Gunal, Izge

    2007-02-01

    There has not been any study regarding comparative gait analysis in patients with intramedullary stemmed prosthesis (ISP) and thrust plate prosthesis (TPP) implanted to each hip. Four patients (three females and one male) who had undergone operation due to coxarthrosis were selected. The mean age was 60.5 (37-78) years. TPP and ISP had been implanted to the left and right hip, respectively, in three patients, and one patient received TPP to the right and ISP to the left hip. Gait was analyzed with a BTS Elite System consisting six cameras and two Kistler force plates using Helen Hayes marker set to assess the gait parameters. The clinical outcome was also evaluated according to Harris hip score (HHS). The average HHS was 95.0 (82-100) points after a mean follow-up of 45.0 (30-50) months for TPP and 94.5 (80-100) points after a follow-up of 60.0 (14-122) months for ISP. Neither of the HHS scores and follow-up time nor gait parameters obtained from the TPP-implanted side were statistically different when compared to those of the ISP-implanted side. TPP and ISP as the implants with their own biomechanical specifications did not produce any remarkable difference in gait.

  10. Optimization of Emergence Profile of Implant Prosthesis: A Literature Review

    Directory of Open Access Journals (Sweden)

    Minoru Sanda

    2018-01-01

    Full Text Available In order to achieve esthetically optimal outcome with implant prosthesis, appropriate topography of emergence profile is crucial. The objective of this review is to explorer current evidence regarding this topic and relevant issue. Extent of interproximal papilla is determined not by the shape of emergence profile but the length between interproximal alveolar bone prominence and interproximal contact of crowns. There have been concerned that multiple times of disconnection and reconnection of abutment enhance peri-implant marginal bone loss, but it’s certified not to be a clinically significant level. Current digital workflow makes this step faster and easier, by copying emergence profile of contralateral tooth or extracted teeth.

  11. Restoration of failing maxillary implant-supported fixed prosthesis with cross arch splinted unilateral zygomatic implant: a clinical report.

    Science.gov (United States)

    Gunaseelan, Rajan; Saravanakumar, Mariappan; Hariharan, Ramasubramanian

    2012-12-01

    Management of one or more failing distal implants in an implant supported fixed prosthesis in a completely edentulous maxilla creates a challenging situation. Restoring immediate function with additional implants in such a situation can be a challenge considering the loss of supporting bone, need for grafting, age, and the patient's desire for immediate fixed dental prosthesis. This clinical report describes a situation where a zygomatic implant has been placed unilaterally and splinted with osseointegrated conventional implants by an immediate fixed provisional restoration.

  12. Osseointegrated silicone finger prosthesis using dental implants: a renovated technique.

    Science.gov (United States)

    Vinnakota, Dileep Nag; Sankar, V Vijay; Chirumamilla, Naveen; Reddy, V Vamsikrishna

    2014-11-01

    In clinical practice, we come across patients with traumatically amputated or congenitally missing partial or complete fingers that can be restored using microsurgical replantation or transplantation procedures. However, in some cases this might not be possible due to systemic or local factors and the lost or missing part has to be replaced prosthetically to offer psychological and functional wellbeing. These prostheses can be constructed with various materials like acrylics or silicone retained with the help of auxiliary aids. However, these prostheses cause some hindrance in performing functions like writing, typing, etc. The aim of the present trial was to ameliorate the existing design of implant supported finger prosthesis. Distal phalange of middle finger replaced with implant supported silicone finger prosthesis is modified by utilizing a metal framework to support silicone material to improve rigidity while working. We could achieve a good function, esthetics and tactile sensibility with this modified design. Whenever, feasible this design can improve the performance and patients feel a deep sense of satisfaction and improved self-esteem with this modified prosthesis.

  13. Photoacoustic determination of blood vessel diameter

    NARCIS (Netherlands)

    Kolkman, R.G.M.; Klaessens, John H.G.M.; Hondebrink, Erwin; Hopman, Jeroen C.W.; de Mul, F.F.M.; Steenbergen, Wiendelt; Thijssen, Johan M.; van Leeuwen, Ton

    2004-01-01

    A double-ring sensor was applied in photoacoustic tomographic imaging of artificial blood vessels as well as blood vessels in a rabbit ear. The peak-topeak time (τ pp) of the laser (1064 nm) induced pressure transient was used to estimate the axial vessel diameter. Comparison with the actual vessel

  14. [Vascular access for haemodyalisis. Comparative analysis of the mechanical behaviour of native vessels and prosthesis].

    Science.gov (United States)

    Bia, D; Zócalo, Y; Armentano, R; Pérez, H; Cabrera, E; Saldías, M; Galli, C; Alvarez, I

    2006-01-01

    The prosthesis nowadays used in the vascular access for haemodialysis have low patency rates, mainly due to the luminal obstruction, determined by the intimal hyperplasia. Several factors have been related to de development of intimal hyperplasia and graft failure. Among them are the differences in the biomechanical properties between the prosthesis and the native vessels. In the searching for vascular prosthesis that overcomes the limitations of the currently used, the cryopreserved vessels (cryografts) appear as an alternative of growing interest. However, it is unknown if the mechanical differences or mismatch between prosthesis and native vessels are lesser when using cryografts. To characterize and compare the biomechanical behaviour of native vessels used in vascular access and cryografts. Additionally, segments of expanded polytetrafluoroethylene (ePTFE) were also evaluated, so as to evaluate the potential biomechanical advantages of the cryografts respect to synthetic prosthesis used in vascular access. Segments from human humeral (n = 12), carotid (n = 12) and femoral (n = 12) arteries, and saphenous vein (n = 12), were obtained from 6 multiorgan donors. The humeral arteries were studied in fresh state. The other segments were divided into two groups, and 6 segments from each vessel were studied in fresh state, while the remaining 6 segments were evaluated after 30 days of criopreservation. For the mechanical evaluation the vascular segments and 6 segments of ePTFE were mounted in a circulation mock and submitted to haemodynamic conditions similar to those of the in vivo. Instantaneous pressure (Konigsberg) and diameter (Sonomicrometry) were measured and used to calculate the viscous and elastic indexes, the compliance, distensibility and characteristic impedance. For each mechanical parameter studied, the mismatch between the prosthesis and the native vessel was evaluated. The ePTFE was the prosthesis with the higher mechanical mismatch (p vascular

  15. Rehabilitation of orbital defect with silicone orbital prosthesis retained by dental implants.

    Science.gov (United States)

    Guttal, Satyabodh Shesharaj; Desai, Jhanvi; Kudva, Adarsh; Patil, Basavaraj R

    2016-01-01

    Orbital defects can result from cancer, birth anomalies, or trauma leading to an onslaught of problems in the function and psyche of the patient. These defects are restored by surgical reconstruction and followed by placement of orbital prosthesis for cosmetic makeup. The use of dental implants in retaining orbital prosthesis improves patient acceptance of the prosthesis owing to better retention and stability than conventional adhesive retained prosthesis. This case report describes a custom-made magnetic retentive assembly anchored by a dental implant which offers the orbital prosthesis the simplicity of self-alignment and ease of use.

  16. Rehabilitation with ear prosthesis linked to osseointegrated implants.

    Science.gov (United States)

    Goiato, Marcelo C; dos Santos, Daniela M; Haddad, Marcela F; Moreno, Amália

    2012-06-01

    The absence of an ear, which can be the result of a congenital malformation, surgical tumour resection or traumatic injury, is a significant aesthetic problem. Attachment of ear prostheses with adhesives can cause local irritation for the wearer and affect the colour of the prostheses. Use of implants in craniofacial reconstruction can improve the retention and stability of prostheses giving to patient greater comfort and security relative to adhesive attachment. The aim of this report was to present a clinical case of a mutilated patient who was rehabilitated by means of installing an ear prosthesis fixed through osseointegrated implants. The patient had two implants installed in the mastoid region that were linked by a bar, and a clip-type system was used. The ear prosthesis was constructed from medical-use silicone, pigmented to match the patient's skin colour and linked to the retention system. The patient's rehabilitation was satisfactory from both a functional and an aesthetic point of view, making it possible for the patient to return to a normal social life and regain lost self-esteem. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

  17. IMPLANT SUPPORTED PROSTHESIS IN A PATIENT WITH PROGERIA: CASE REPORT

    Science.gov (United States)

    Ceylan, Gözlem; Yılmaz, Nergiz; Şenyurt, Özgün; Kunt, Göknil Ergün

    2009-01-01

    Prosthodontic rehabilitation can be accomplished with fixed, overdenture, complete, or implant-retained prostheses. Dental treatment overcomes the patient’s functional, psychological, esthetic and phonation problems. Remaining healthy teeth may allow the dentist to fabrícate a removable partial overdenture, fixed partial prosthesis or implant - supported prosthesis. The retention of a number of abutments helps maintain a positive ridge form with greater height and volume of the alveolar bone, improving masticatory performance, as well as providing a more stable prostheses. Dental patients who have medical problems need many treatment procedures. Multidisciplinary treatment planning is invaluable for patient’s dental health. Progeria is a rare genetic condition where symptoms resembling aspects of aging are manifested at an early age. characteristic clinical findings of Progeria disease include abnormalities of the skin and hair in conjunction with char-acteristic facial features and skeletal abnormalities. The characteristic facies show protruding ears, beaked nose, thin lips with centrofacial cyanosis, prominent eyes, frontal and parietal bossing with pseudohydrocephaly, midface hypoplasia with micrognathia and large anterior fontanel. The other reported anomalies are dystrophic nails, hypertrophic scars and hypoplastic nipples. The findings that are nearly interested in dentistry are delayed dentition, anodontia, hypodontia, or crowding of teeth. This article presents the multidisciplinary dental treatment planning includes surgical, endodontic and prosthetic treatment of a patient with a history of progeria. In this case complete-arch fixed prostheses in both maxilla and mandible, supported by a combination of im-plants and teeth are reported. PMID:19754475

  18. [Study of satisfaction of testicular prosthesis implantation in children].

    Science.gov (United States)

    Martínez, Y; Millán, A; Gilabert, R; Delgado, L; De Agustín, J C

    2012-01-01

    Testicular absence may cause psychological trauma in children. It can be avoided by placing testicular prosthesis (TP). However there is no consensus on the optimal age of implantation. We evaluate the results of TP implantation and their complications, as well as patient and family satisfaction. This is a retrospective study of TP implanted between 2004-2010 in our center. Variables analyzed are: age, size and side, indication, surgical technique, complications and comorbidity. Telephone survey was done by a single interviewer to 50 families. general family satisfaction, characteristics of the prosthesis (size, shape, location and consistency), body image and psychological situation of the child, duration of analgesia after surgery, reoperation rate, and family advice to other parents. Statistical analysis with SPSS-18.0. 107 prostheses were placed (4 bilateral, 64 left and 35 rights) at a mean age of 70,10 +/- 58,6 months. The most common indication was cryptorchidism (48.2%). Initial inguinal approach in 69%, and simultaneous contralateral orchidopexy in 29.9%. Only one patient refused the prostheses. In 71% the mother was interviewed. Parents consider size, shape and position appropriate in 55.6%, 66.7% and 82.22% respectively. Hard consistency of TP was considered in 82.3% of the patients. Psychological problems were absent in 86.7%. Nighty five percent would be willing to replace when it was necessary. Parents would recommend the intervention to parents in the same situation in 86.7%. Testicular prosthesis avoids psychological trauma. The lack of satisfaction regarding to the small size and hardness makes necessary to replace the TP in adulthood. An open question remains whether we should consider the placement of TP in early ages, or if we should establish some indications based on a more rational communication with the family.

  19. Amputation and prosthesis implantation shape body and peripersonal space representations

    OpenAIRE

    Canzoneri, Elisa; Marzolla, Marilena; Amoresano, Amedeo; Verni, Gennaro; Serino, Andrea

    2013-01-01

    Little is known about whether and how multimodal representations of the body (BRs) and of the space around the body (Peripersonal Space, PPS) adapt to amputation and prosthesis implantation. In order to investigate this issue, we tested BR in a group of upper limb amputees by means of a tactile distance perception task and PPS by means of an audio-tactile interaction task. Subjects performed the tasks with stimulation either on the healthy limb or the stump of the amputated limb, while wearin...

  20. Dorsal Phalloplasty to Preserve Penis Length after Penile Prosthesis Implantation

    Directory of Open Access Journals (Sweden)

    Osama Shaeer

    2017-03-01

    Full Text Available Objectives: Following penile prosthesis implantation (PPI, patients may complain of a decrease in visible penis length. A dorsal phalloplasty defines the penopubic junction by tacking pubic skin to the pubis, revealing the base of the penis. This study aimed to evaluate the efficacy of a dorsal phalloplasty in increasing the visible penis length following PPI. Methods: An inflatable penile prosthesis was implanted in 13 patients with severe erectile dysfunction (ED at the Kamal Shaeer Hospital, Cairo, Egypt, from January 2013 to May 2014. During the surgery, nonabsorbable tacking sutures were used to pin the pubic skin to the pubis through the same penoscrotal incision. Intraoperative penis length was measured before and after the dorsal phalloplasty. Overall patient satisfaction was measured on a 5-point rating scale and patients were requested to subjectively compare their postoperative penis length with memories of their penis length before the onset of ED. Results: Intraoperatively, the dorsal phalloplasty increased the visible length of the erect penis by an average of 25.6%. The average length before and after tacking was 10.2 ± 2.9 cm and 13.7 ± 2.8 cm, respectively (P <0.002. Postoperatively, seven patients (53.8% reported a longer penis, five patients (38.5% reported no change in length and one patient (7.7% reported a slightly shorter penis. The mean overall patient satisfaction score was 4.9 ± 0.3. None of the patients developed postoperative complications. Conclusion: A dorsal phalloplasty during PPI is an effective method of increasing visible penis length, therefore minimising the impression of a shorter penis after implantation.

  1. Percutaneous aortic valve implantation of the Medtronic CoreValve self-expanding valve prosthesis via left subclavian artery access: the first case report in Greece.

    Science.gov (United States)

    Karavolias, George K; Georgiadou, Panagiota; Houri, Mazen; Sbarouni, Eftihia; Thomopoulou, Sofia; Tsiapras, Dimitrios; Smirli, Anna; Balanika, Marina; Voudris, Vassilis

    2010-01-01

    This case report describes a percutaneous aortic valve implantation with the Medtronic CoreValve selfexpanding valve prosthesis in a patient with severe aortic stenosis. The approach was made via the left subclavian artery because of the lack of femoral vessel access. The patient was a 78-year-old female with breathlessness on minimal effort, a recent hospitalisation due to pulmonary oedema, and frequent episodes of pre-syncope; surgical valve replacement had been ruled out. The prosthetic valve was successfully implanted with mild paravalvular aortic regurgitation. At 30 days, the patient's clinical condition had significantly improved, with excellent functioning of the aortic valve prosthesis.

  2. Axial penile rigidity influences patient and partner satisfaction after penile prosthesis implantation.

    Science.gov (United States)

    Al Ansari, Abdulla; Talib, Raidh A; Canguven, Onder; Shamsodini, Ahmad

    2013-09-26

    Penile prosthesis implantation is one of the treatment choices that is kept for patients who were not satisfied with other treatments. Although penile prosthesis satisfaction rates are higher, there are some dissatisfied patients. The patients’ reasons are mostly shortness and softness of implanted prosthesis. It was previously demonstrated that penile axial rigidity of more than 500 grams is enough for successful vaginal intromission. To our knowledge, there is no study comparing axial rigidity of penile prosthesis and satisfaction. The aim of this study was to examine whether axial rigidity of penile prosthesis had impact on patient and partner satisfaction. We enrolled one hundred patients who were implanted penile prosthesis before to evaluate their penile axial rigidity. We used Rigidometry (by using the digital inflection rigidometer) to assess the minimal axial pressure to bend the implanted penis. We demonstrated that mean axial pressure to bend the implanted penis was 984.8 ± 268.7 grams. Overall satisfaction score with the penile prosthesis implant was 4.55 and 4.49 (out of 5) in patients and partners, respectively. In total, seven men were unsatisfied with their implant and reported a mean satisfaction score of 0.6 ± 0.48 (out of 5). All prostheses types showed good and more than 500 grams axial rigidity. The patients with Ambicor type, which were buckled at about 710.5 grams, showed worse satisfaction rates in comparison to other prostheses in two patients. Digital inflection rigidometer results of other penile prosthesis types in unsatisfied patient were 842.0, 872.0, 887.0 and 920 g. in CX700, Titan, Genesis and Titan OTR, respectively. We demonstrated that dissatisfaction rate was highest in Ambicor prosthesis implanted patients. Additionally, patients with 3-piece penile prosthesis were more satisfied than 2-piece or malleable ones, interestingly, although some cases had lower axial rigidity results.

  3. A provisional fixed partial denture for an implant prosthesis.

    Science.gov (United States)

    Hansen, Paul A; Kim, Eunghwan

    2010-01-01

    This article presents a technique for fabricating an esthetic provisional restoration on multiple implants. Fabricating a provisional restoration allows the dentist to make a replica of the desired restoration. The incisal edge can be placed for esthetics and function in the new provisional restoration, allowing patients to evaluate comfort and test their ability to speak with the contour of the provisional restoration. Patients can evaluate both the ease of cleaning the restoration and how tissue esthetics can be duplicated to their satisfaction. By adding acrylic resin to or removing it from the provisional, the dentist can easily change the restoration until the patient is satisfied with the esthetic and functional result. This technique will allow the dentist to fabricate the provisional prosthesis quickly, while the patient is in the chair.

  4. Transforming an existing fixed provisional prosthesis into an implant-supported fixed provisional prosthesis with the use of healing abutments.

    Science.gov (United States)

    Chaimattayompol, Nopsaran; Emtiaz, Shahram; Woloch, Michael M

    2002-07-01

    Maintaining a fixed provisional prosthesis through all phases of complex implant prosthodontic therapy for a soon-to-be completely edentulous arch is a difficult task. This article focuses on the treatment phase in which teeth and/or transitional implants supporting a provisional fixed partial denture are removed. The described technique makes use of healing abutments to support a modified provisional fixed partial denture. This protocol ensures patient comfort and allows proper soft tissue healing before definitive implant abutment selection. It also eliminates the placement of interim implant abutments.

  5. First report on a human percutaneous transluminal implantation of a self-expanding valve prosthesis for interventional treatment of aortic valve stenosis.

    Science.gov (United States)

    Grube, Eberhard; Laborde, Jean C; Zickmann, Bernfried; Gerckens, Ulrich; Felderhoff, Thomas; Sauren, Barthel; Bootsveld, Andreas; Buellesfeld, Lutz; Iversen, Stein

    2005-12-01

    Percutaneous aortic valve replacement is a new technology for the treatment of patients with significant aortic valve stenosis. We present the first report on a human implantation of a self-expanding aortic valve prosthesis, which is composed of three bovine pericardial leaflets inserted within a self-expanding nitinol stent. The 73-year-old woman presented with severe symptomatic aortic valve stenosis (mean transvalvular gradient of 45 mmHg; valve area of 0.7 cm2). Surgical valve replacement had been declined for the patient because of comorbidities, including previous bypass surgery. A retrograde approach via the common iliac artery was used for valve deployment. The contralateral femoral vessels were used for a temporary extracorporal circulation, unloading the left ventricle during the actual stent expansion. Clinical, hemodynamic, and echocardiographic outcomes were assessed serially during the procedure. Clinical and echocardiographic follow-up at day 1, 2, and 14 post procedure was performed to evaluate the short-term outcome. The prosthesis was successfully deployed within the native aortic valve, with accurate and stable positioning and with no impairment of the coronary artery or vein graft blood flow. 2D and doppler echo immediately after device deployment showed a significant reduction in transaortic mean pressure gradient (from 45 to 8 mmHg) without evidence of aortic or mitral valve insufficiency. The clinical status has then significantly improved. These results remained unchanged up to the day 14 follow-up. This case report demonstrates a successful percutaneous implantation of a self-expanding aortic valve prosthesis with remarkable functional and clinical improvements in the acute and short-term outcome. Copyright (c) 2005 Wiley-Liss, Inc.

  6. Design and in-vitro evaluation of a tissue engineered large vessel prosthesis

    Science.gov (United States)

    Mahmood, Ayesha

    Tissue engineering of large diameter blood vessels can offer a promising long-term solution to the large population suffering from congenital vascular defects and other vascular disease. In this report design, assembly, in vitro maturation and evaluation of a large diameter, chitosan-based prosthesis is described. To facilitate cell adhesion and proliferation, collagen was included as a scaffold component to a chitosan scaffold. In vitro studies evaluated the role of collagen content, crosslinker type and crosslinking density on degradation kinetics, mechanical properties and cellular interactions. Finally, the vessel scaffold (ID = 12 mm, OD = 15 mm) was fabricated from a moderately cross-linked, 90%/10% chitosan/collagen material. A tubular scaffold with gradient porosity and interconnected pores was generated by controlled freezing and lyophilization of the polymer. For graft culture laminar and pulsatile flow systems were designed and porous scaffolds were seeded with vascular cells under static conditions. Laminar system grafts were seeded and cultured/analyzed over an 8 week period (15ml/min). For the pulsatile system SMC were seeded and after 2 weeks of pulsatile flow culture (360ml/min, 82 beats/min) microvascular EC were seeded lumenally to initiate a microvascular network followed by aortic EC seeding at 3 weeks. For both systems, cell viability at different culture periods showed the formation of high density of cell within few weeks of graft culture. However, the pulsatile flow system graft showed a significant increase in mechanical properties and ECM protein (collagen and elastin) deposition overtime. This novel chitosan based tissue engineered vascular graft shows promising results for large vessel replacements.

  7. Maxillary Implant-Supported Fixed Prosthesis: A Survey of Reviews and Key Variables for Treatment Planning.

    Science.gov (United States)

    Gallucci, German O; Avrampou, Marianna; Taylor, James C; Elpers, Julie; Thalji, Ghadeer; Cooper, Lyndon F

    2016-01-01

    This review was conducted to provide information to support the establishment of clinical guidelines for the treatment of maxillary edentulism using implant-supported fixed dental prostheses. Initial efforts were directed toward a systematic review with a defined PICO question: "For maxillary edentulous patients with dental implants treated using a fixed prosthesis, what is the impact of prosthesis design on prosthesis survival and complications?" Following a title search of more than 3,000 titles identified by electronic search of PubMed, 180 articles were identified that addressed the clinical evaluation of maxillary dental implant prostheses. The broad methodologic heterogeneity and clinical variation among reports precluded this approach for a systematic review. The information was extracted using a standardized extraction table by two pairs of investigators, and the reported outcomes were then summarized according to reported outcomes for implant prostheses supported by four, six, or eight implants using unitary or segmented prostheses. This review indicated that high prosthetic survival is observed using all approaches. The advantages of using fewer implants and a unitary prosthesis are revealed in the surgical phases, and complications commonly involve the fracture or detachment of acrylic teeth and reduced access for proper oral hygiene and related biologic complications. Using six implants typically involved grafting of posterior regions with advantages of reduced cantilevers and redundancy of implant support. Reduced prosthesis survival in these cases was associated with poor implant distribution. Segmented prostheses supported by six or more implants offered greater prosthetic survival, perhaps due to posterior implant placement. Advantages of a segmented prosthesis included pragmatic issues of accommodating divergent implants, attaining passive fit, combining prosthetic materials, and relative simplicity of repair. The existing literature demonstrated

  8. Penile Prosthesis Implantation in Patients with a History of Total Phallic Construction.

    Science.gov (United States)

    Zuckerman, Jack M; Smentkowski, Katherine; Gilbert, David; Storme, Oscar; Jordan, Gerald; Virasoro, Ramon; Tonkin, Jeremy; McCammon, Kurt

    2015-12-01

    Outcomes following penile prosthesis implantation in patients with a history of total phallic construction are not well described. The aim of this study was to evaluate outcomes following neophallus penile prosthesis placement. Retrospective review penile prosthesis placement in patients with prior total phallic construction. GORE-TEX® (Gore Medical, Flagstaff, AZ) sleeve neotunica construction was utilized in all patients. Success defined as patient sexual activity with a functioning prosthesis. Thirty-one patients underwent neophallic prosthesis implantation at a mean 35.6 years of age. Prosthesis placement occurred at an average 56.3 months following phallic construction and follow-up was a mean of 59.7 months. Malleable prostheses were placed in 21 patients and inflatable in 10; implants were bilateral in 94%. Six percent experienced operative complications including a bladder injury (1) and phallic flap arterial injury (1). Postoperative complications occurred in 23% at a median 5.5 months following placement. Five prostheses were explanted secondary to infection or erosion and two additional required revisions. Of the explanted prosthesis two were later replaced without further complication. Eighty-one percent of patients were sexually active following prosthesis placement. Penile prosthesis placement is possible in patients with prior penile reconstruction/phallic construction. Although complications rates appear to be elevated in this population compared with historic controls of normal anatomic men, the majority of patients in this series were sexually active following prosthesis placement. This demonstrates the utility of prosthesis implantation in these difficult patients. © 2015 International Society for Sexual Medicine.

  9. NMR blood vessel imaging method and apparatus

    International Nuclear Information System (INIS)

    Riederer, S.J.

    1988-01-01

    A high speed method of forming computed images of blood vessels based on measurements of characteristics of a body is described comprising the steps of: subjecting a predetermined body area containing blood vessels of interest to, successively, applications of a short repetition time (TR) NMR pulse sequence during the period of high blood velocity and then to corresponding applications during the period of low blood velocity for successive heart beat cycles; weighting the collected imaging data from each application of the NMR pulse sequence according to whether the data was acquired during the period of high blood velocity or a period of low blood velocity of the corresponding heart beat cycle; accumulating weighted imaging data from a plurality of NMR pulse sequences corresponding to high blood velocity periods and from a plurality of NMR pulse sequences corresponding to low blood velocity periods; subtracting the weighted imaging data corresponding to each specific phase encoding acquired during the high blood velocity periods from the weighted imaging data for the same phase encoding corresponding to low blood velocity periods in order to compute blood vessel imaging data; and forming an image of the blood vessels of interest from the blood vessel imaging data

  10. Prosthesis-patient mismatch after transcatheter aortic valve implantation using the Edwards SAPIEN™ prosthesis.

    Science.gov (United States)

    Van Linden, Arnaud; Kempfert, Jörg; Blumenstein, Johannes; Rastan, Ardawan; Holzhey, David; Lehmann, Sven; Mohr, Friedrich W; Walther, Thomas

    2013-08-01

    Prosthesis-patient mismatch (PPM) is defined as a too small effective orifice area (EOA) of the prosthetic valve in relation to the patient's body size and has been documented to be related to adverse outcomes after conventional aortic valve replacement (AVR). Aim of this study was to analyze the incidence of PPM after transcatheter aortic valve implantation (T-AVI) using the Edwards SAPIEN prosthesis and its relation to postoperative outcome. 200 consecutive high-risk patients underwent transapical aortic valve implantation (TA-AVI) between February 2006 and January 2009 and fulfilled 1 year follow-up were included. Severe PPM was defined as indexed EOA (EOAi) <0.65 cm2/m2 and moderate PPM as EOAi = 0.65-0.85 cm2/m2, EOA was calculated from transthoracic echocardiographic (TTE) measurements using the continuity equation. Total 112 patients with sufficient postoperative TTE image quality formed the study group. EOAi increased from 0.3 ± 0.1 cm2/m2 (preoperatively) to 1.1 ± 0.4 cm2/m2 after TA-AVI (p < 0.001). According to the standard definitions, PPM was seen in 38.4% of the patients and 9.8% presented with severe PPM. The occurrence of PPM had neither an effect on clinical outcome in terms of NYHA class nor on survival. Patients with PPM had significantly higher postoperative transprosthetic gradients (mean gradient 10.4 ± 4.1 versus 7.1 ± 3.0 mm Hg, p < 0.001). Based on the in vitro EOA data obtained from pulse duplicator measurements, however, none of the patients was judged to have PPM. Transcatheter AVI provides good antegrade hemodynamic function and EOAi improves significantly. According to standardized evaluations PPM occurs after TA-AVI, but it is not associated with adverse outcomes. Thus use of the continuity equation may not adequately reflect the situation after T-AVI or the current definition of PPM is not suitable for T-AVI prostheses. Georg Thieme Verlag KG Stuttgart · New York.

  11. Is Hba1c level of diabetic patients associated with penile prosthesis implantation infections?

    Science.gov (United States)

    Canguven, Onder; Talib, Raidh; El Ansari, Walid; Khalafalla, Kareim; Al Ansari, Abdulla

    2018-03-09

    Diabetes mellitus is an important risk factor for erectile dysfunction (ED). Penile prosthesis implantation surgery is the final solution for diabetic patients with ED, but infections thereof are still a serious risk factor. While some studies suggest that most infections associated with penile prosthesis implantation are associated to high glycated hemoglobin (HbA1c) levels, other research did support such relationship. The current study assessed retrospectively, the association between HbA1c level and penile prosthesis surgery infection. We retrieved and reviewed the records of 300 diabetic patients who had penile prosthesis surgery at our Institution (January 2012-November 2016). Patients' mean age was 55.26 ± 10.9 years (31% patients were prosthesis infection among patients with HbA1c ≤ 9% was 0.9%, compared with 0% among patients with HbA1c > 9%. Prosthesis infection risk did not significantly increase with higher HbA1c levels, with no meaningful difference in the median or mean level of HbA1c in the infected and non-infected diabetic patients. Findings do not support the use of HbA1c values among diabetic patients who are candidates for penile prosthesis implantation surgery in order to identify and exclude those who might be prone to increased risk of prosthesis infections. Future studies would benefit from larger sample sizes in order to support or refute our findings.

  12. Incidence and impact of prosthesis-patient mismatch after transcatheter aortic valve implantation.

    Science.gov (United States)

    Bleiziffer, Sabine; Hettich, Ina; Hutter, Andrea; Wagner, Anke; Deutsch, Marcus-André; Piazza, Nicolo; Lange, Rüdiger

    2013-05-01

    The study aim was to investigate the incidence of patient-prosthesis mismatch (PPM) with new catheter valves, and its influence on the patients' clinical state. At present, few echocardiographic data are available on the incidence and impact of PPM with the CoreValve and Sapien prostheses for transcatheter aortic valve implantation (TAVI). The reliability of effective orifice area (EOA) measurements was assured by awaiting an interval of six months after TAVI. Of 256 survivors after TAVI, 149 complete echocardiographic data sets were available for the assessment of the indexed EOA (iEOA). In total, 106 CoreValve prostheses and 43 Sapien prostheses were implanted in this high-risk cohort (mean age 81 +/- 6 years, mean logistic EuroSCORE 20 +/- 13%). The overall incidence of PPM (iEOA body surface area were more likely to develop PPM (p = 0.001), while the prosthesis type, native annulus diameter, preoperative EOA, gender and prosthesis size had no influence. The mean aortic gradient was significantly higher in patients with PPM. A reduction in the left ventricular end-diastolic diameter was seen in all patients, without significant differences between groups. There were no differences in postoperative NYHA class or self-assessed health state between patients with or without PPM. PPM was common after TAVI in the presented cohort, presumably because the native calcium masses narrow the outflow area available for blood flow. As expected for low gradients, there was no impairment of left ventricular dimension regression or clinical state of the patients, even if severe PPM was present. Based on the presented data, it is assumed that PPM might be less relevant in TAVI patients.

  13. Distinguishing Failure to Cure From Complication After Penile Prosthesis Implantation.

    Science.gov (United States)

    Pineda, Miguel; Burnett, Arthur L

    2017-05-01

    A successful penile prosthesis implantation (PPI) surgery can be defined by outcomes beyond the absence of complications. To introduce the concept of failure to cure (FTC) in the context of PPI to more accurately gauge postoperative outcomes after PPI. Consecutive patients from our sexual function registry who underwent PPI from January 2011 to December 2013 were analyzed. Demographics, previous treatment of erectile dysfunction, comorbidities, social history, postoperative problems (POPs), and surgical outcomes were tabulated. Patients completed the International Index of Erection Function (IIEF) and the Erectile Dysfunction Inventory of Treatment Satisfaction questionnaires. We defined a complication, according to the Clavien-Dindo classification, as any deviation from the ideal postoperative course that is not inherent in the procedure and does not constitute an FTC. FTC was defined as a POP that was not a complication. The χ 2 tests, t-tests, or Wilcoxon rank-sum tests were used. Patient-reported and objective outcomes after PPI. Our enrollment consisted of 185 patients, and we contacted 124 (67%). Of these, 16 (12.9%) had a POP requiring reoperation. Eight patients developed surgical complications (three infections, four erosions, and one chronic pain). Eight patients had FTC (four malpositions and four malfunctions). Factors that correlated with POPs were previous PPI, body mass index higher than 30 kg/m 2 , and previous treatment with intracorporal injections (P .05 for all comparisons). POPs after PPI surgery can be more accurately categorized using the Clavien-Dindo classification of surgical complications to more clearly distinguish surgical complications from FTC. Limitations of our study include its retrospective approach. Our series included a large proportion of patients treated for prostate cancer, which limits the generalizability of our findings. We also had a relatively short median follow-up time of 27 months. Patient-reported outcome

  14. Use of a hydroxyapatite orbital implant in a cosmetic corneoscleral prosthesis after enucleation in a horse.

    Science.gov (United States)

    Gilger, Brian C; Pizzirani, Stefano; Johnston, Lisa C; Urdiales, Nicholas R

    2003-02-01

    A hydroxyapatite orbital implant was used after enucleation of an eye from a 5-year-old performance horse. A custom-made corneoscleral prosthesis was made and fitted over the hydroxyapatite implant. The implant and surgery were well tolerated. Placement of a cosmetic prosthesis is desired after enucleation of equine eyes to allow horses to return to competition. Synthetic spheres consisting of methylmethacrylate or silicone have been used, although reported complications have included extrusion, infection, and poor cosmetic results. Hydroxyapatite orbital implants made from marine coral allow vascular and fibrous tissue growth from the host orbit into the implant, which decreases the possibility of implant extrusion or infection and allows enhanced healing of defects in the overlying conjunctiva. Extraocular muscle fixation onto the implant permits motility and assists in the prevention of implant extrusion.

  15. Attachment-retained gingival prosthesis for implant-supported fixed dental prosthesis in the maxilla: a clinical report.

    Science.gov (United States)

    Aparecida de Mattias Sartori, Ivete; Uhlendorf, Yuri; Padovan, Luiz Eduardo Marques; Junior, Paulo Domingos Ribeiro; Melo, Ana Cláudia Moreira; Tiossi, Rodrigo

    2014-12-01

    The rehabilitation of edentulous maxillae is a complex procedure due to the involvement of esthetic and functional requirements. A trial maxillary denture can be used to identify the need for adequate upper lip support when replacing removable complete dentures by implant-fixed dental prostheses. This clinical report describes the outcome of the rehabilitation of an edentulous atrophic maxilla with unfavorable maxillomandibular relationship and deficient upper lip support. A trial denture was fabricated and used to diagnose the need for a prosthesis capable of restoring the upper lip support. The reduced upper lip support was also confirmed by a lateral cephalogram. The patient was rehabilitated by an implant-fixed dental prosthesis associated with an attachment-retained gingival prosthesis. The case presented shows that when loss of upper lip support is detected and the patient does not wish to undergo further surgical reconstruction procedure, the retention of a gingival prosthesis using a ball attachment is a satisfactory treatment option. © 2014 by the American College of Prosthodontists.

  16. Immediate loading of zygomatic implants: A systematic review of implant survival, prosthesis survival and potential complications.

    Science.gov (United States)

    Tuminelli, Frank J; Walter, Leora R; Neugarten, Jay; Bedrossian, Edmond

    Zygomatic implants have been utilised for the treatment of the severely atrophic maxilla since 1998. However, few articles exist as to the success of zygomatic implants and immediate loading of its prosthesis. To systematically review the outcome of immediate loaded zygomatic implants. An electronic PubMed search was performed to identify case reports, prospective and retrospective studies of immediately loaded zygomatic implants with a mean follow-up of 12 months. Assessment of the identified studies was performed using the Delphi method. Reviewers independently assessed the articles for inclusion, with a facilitator coordinating responses. A consensus was reached on the articles that were included. The search provided 236 titles for immediately loaded zygomatic implants and resulted in 106 abstracts for analysis. Full-text analysis was performed on 67 articles, resulting in the inclusion of 38 articles for this systematic review. Based on the present systematic review, the authors report that immediately loading zygomatic implants for the restoration of the severely atrophic maxilla presents a viable alternative for treatment of the atrophic maxilla.

  17. Preoperative counseling and expectation management for inflatable penile prosthesis implantation.

    Science.gov (United States)

    Narang, Gopal L; Figler, Bradley D; Coward, Robert M

    2017-11-01

    The inflatable penile prosthesis (IPP) is the gold standard surgical treatment for medical refractory erectile dysfunction (ED). While the modern IPP has enjoyed high satisfaction rates as a product of its continued innovation, reliability, and performance, patient dissatisfaction can still occur. IPP implantation restores physiologic function with cosmetic and psychological consequences, both of which place inherent emphasis on preoperative counseling and expectation management. This review aims to highlight the complex nature of such counseling and provide practitioners with a roadmap to navigate the landscape. Preoperative counseling begins with appropriate patient selection and identification of those patients who are at risk for dissatisfaction as a result of personality characteristics. The informed consent provides a natural framework to discuss the host of complications and risks that are associated with surgery, including infection, device malfunction, damage to nearby structures, and device erosion. Device selection is a nuanced process that merges patient preference with clinical factors and consideration. We address device selection through a description of cylinder construction, pump design, and reservoir placement in the context of preoperative counseling. Lastly, we draw attention to expectation management with a specific focus on possible post-operative changes to penile length and sensation as well as partner involvement. The modern IPP provides excellent results with high patient and partner satisfaction. Ultimately, satisfaction is dependent on multiple factors, but providing accurate, realistic counseling and expectation management prepares patients for the best possible outcomes.

  18. Implantable Prosthesis of Osseous Conduction (BAHA: Case Report

    Directory of Open Access Journals (Sweden)

    Stumpf, Claudia Mittelmann

    2011-04-01

    Full Text Available Introduction: The implantable prosthesis of osseous conduction (BAHA is deemed to be an excellent option in the auditory rehabilitation of patients with conductive and mixed hearing loss, unilaterally or bilaterally, and unilateral sensorineural hearing loss. It has been a good advantage over the conservative bone conduction apparatus and those of individual sound-amplifier apparatus (ISAA, when their usage becomes unfeasible because of chronic otitis externa, which has a hard clinic control. Objective: To introduce the first BAHA case performed in Brazil, as duly authorized by ANVISA (National Agency for Sanitary Surveillance, to rehabilitate the mixed hearing loss with occurrences of chronic otitis externa. Method: 50-year-old female patient with right-ear moderate and left-ear severe hearing loss, bilateral tinnitus derived from otosclerosis, was submitted to 04 surgeries of stapedotomy and unable to use ISAA as a result of otorrhea and bilateral otalgia. The medical and audiological evaluation indicated the benefit of using BAHA. Having surgery been performed and BAHA implemented, the patient showed a significant improvement in audiometric thresholds, speech perception and distinction, as well as she declared to be extremely satisfied with the esthetic factor. Final commentaries: BAHA surgical process is safe, simple and swift, thus providing excellent audiological results and a higher degree of satisfaction to patients.

  19. Subconjunctival Hemorrhage (Broken Blood Vessel in Eye)

    Science.gov (United States)

    Subconjunctival hemorrhage (broken blood vessel in eye) Overview A subconjunctival hemorrhage (sub-kun-JUNK-tih-vul HEM-uh-ruj) ... may not even realize you have a subconjunctival hemorrhage until you look in the mirror and notice ...

  20. Three-dimensional finite element analysis of different implant configurations for a mandibular fixed prosthesis.

    Science.gov (United States)

    Fazi, Giovanni; Tellini, Simone; Vangi, Dario; Branchi, Roberto

    2011-01-01

    The distribution of stresses in bone, implants, and prosthesis were analyzed via three-dimensional finite element modeling in different implant configurations for a fixed implant-supported prosthesis in an edentulous mandible. A finite element model was created with data obtained from computed tomographic scans of a human mandible. Anisotropic characteristics for cortical and cancellous bone were incorporated into the model. Six different configurations of intraforaminal implants were tested, with the number of implants varying from three to five and the distal implants inserted either parallel to the other implants or tilted distally by 17 or 34 degrees. A prosthetic structure connecting the implants was designed, with 20-mm posterior cantilevers for the parallel implant configurations, and a load of 200 N was applied to the distal portion of the cantilevers. Stresses were measured at the level of the implant, the prosthetic structure, and the bone. Bone-level stresses were analyzed at the implant-bone interface, at the external cortical bone surface, distal to the terminal implant, and in the cancellous bone along the implant body. A three-parallel-implant configuration resulted in higher stress in the implant and bone than configurations with four or five parallel implants. Configurations with the distal implants tilted resulted in a more favorable stress distribution at all levels. In parallel-implant configurations for fixed implant-supported mandibular prostheses, four and five implants resulted in similar stress distribution in the bone, framework, and implants. A distribution of four implants with the distal implants tilted 34 degrees (ie, the "All-on-Four" configuration) resulted in a favorable reduction of stresses in the bone, framework, and implants.

  1. Effect of joining the sectioned implant-supported prosthesis on the peri-implant strain generated in simulated mandibular model

    Directory of Open Access Journals (Sweden)

    Ipsha Singh

    2017-01-01

    Full Text Available Aim: The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering. Materials and Methods: A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge. Results: Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains. Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains. Conclusions: Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.

  2. Detection of blood vessels on coronary cineangiograms

    International Nuclear Information System (INIS)

    Yanagihara, Yosio; Sugahara, Tetsuo; Uyama, Chikao

    1988-01-01

    To determine the most suitable filter for measuring blood vessel width on a coronary cineagiogram, several sizes of vessel phantoms were taken under different energies and contrast substance densities on cine film and the vessel widths were calculated by using several edge detection filters. Among the filters, the entropy and Gaussian filters were found to be twice as accurate as the derivative filters. The entropy filter was applied to one frame of a coronary angiogram, and the detected vessel edges were as accurate as the determined by a radiologist. This filter can be applied to coronary cineangiograms, including stenosed sites. (author)

  3. Suprapubic Cystostomy for the Management of Urethral Injuries During Penile Prosthesis Implantation

    Directory of Open Access Journals (Sweden)

    Uzoma A. Anele, MD

    2014-12-01

    Conclusion: Primary urethral repair followed by temporary suprapubic cystostomy offers a surgical approach to complete PP implantation successfully in patients who sustain urethral injury complications, particularly for complex PP surgeries. Anele UA, Le BV, and Burnett AL. Suprapubic cystostomy for the management of urethral injuries during penile prosthesis implantation. Sex Med 2014;2:178–181.

  4. Refabrication of an implant-retained auricular prosthesis using clip attachment pickup technique.

    Science.gov (United States)

    Kethireddy, Sanketh; Kethireddy, Keerthi

    2017-01-01

    Increased patient acceptance and widespread use have led to a greater demand for refabrication of existing maxillofacial prostheses exhibiting wear and tear. Refabricating an osseointegrated implant-retained silicone auricular prosthesis on the existing Hader bar is a challenging task if it is performed without removing it. Therefore, an attachment level impression method is utilized for the refabrication of a new prosthesis on an existing Hader bar framework without removing it from the patient's defect. This case report discusses a modification of the Mahidol University technique. This modification provides a simple, speedy, and convenient method through which the relation between the metal framework and attachments could be obtained precisely. This precision allowed for easy fabrication of the acrylic housing, which in turn results in better adaptation of the auricular prosthesis to the patient's face. Therefore, this technique offers advantages to both the prosthetist in fabrication and the patient in facilitating him continue to wear his existing implant-retained prosthesis during refabrication process.

  5. Computer-guided implant planning using a preexisting removable partial dental prosthesis.

    Science.gov (United States)

    Kim, Jong-Eun; Shim, June-Sung

    2017-01-01

    Converting a conventional removable partial dental prosthesis (RPDP) into an implant-assisted removable partial dental prosthesis (IARPDP) may be facilitated by using data from the intaglio surface of the RPDP for proper implant placement. This procedure can be done by connecting the data from the intaglio surface of the RPDP to the residual ridge data of the cone beam computed tomography scan with implant planning software. However, although a misplaced implant under an RPDP can cause various complications, as yet, no technique has connected the information on a patient's existing RPDP to the implant planning software. This article presents computer-guided implant planning, using a patient's existing RPDP. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. [Total cervical disk replacement--implant-specific approaches: keel implant (Prodisc-C intervertebral disk prosthesis)].

    Science.gov (United States)

    Korge, Andreas; Siepe, Christoph J; Heider, Franziska; Mayer, H Michael

    2010-11-01

    Dynamic intervertebral support of the cervical spine via an anterolateral approach using a modular artificial disk prosthesis with end-plate fixation by central keel fixation. Cervical median or mediolateral disk herniations, symptomatic cervical disk disease (SCDD) with anterior osseous, ligamentous and/or discogenic narrowing of the spinal canal. Cervical fractures, tumors, osteoporosis, arthrogenic neck pain, severe facet degeneration, increased segmental instability, ossification of posterior longitudinal ligament (OPLL), severe osteopenia, acute and chronic systemic, spinal or local infections, systemic and metabolic diseases, known implant allergy, pregnancy, severe adiposity (body mass index > 36 kg/m2), reduced patient compliance, alcohol abuse, drug abuse and dependency. Exposure of the anterior cervical spine using the minimally invasive anterolateral approach. Intervertebral fixation of retainer screws. Intervertebral diskectomy. Segmental distraction with vertebral body retainer and vertebral distractor. Removal of end-plate cartilage. Microscopically assisted decompression of spinal canal. Insertion of trial implant to determine appropriate implant size, height and position. After biplanar image intensifier control, drilling for keel preparation using drill guide and drill bit, keel-cut cleaner to remove bone material from the keel cut, radiologic control of depth of the keel cut using the corresponding position gauge. Implantation of original implant under lateral image intensifier control. Removal of implant inserter. Functional postoperative care and mobilization without external support, brace not used routinely, soft brace possible for 14 days due to postoperative pain syndromes. Implantation of 100 cervical Prodisc-C disk prostheses in 78 patients (average age 48 years) at a single center. Clinical and radiologic follow-up 24 months postoperatively. Significant improvement based on visual analog scale and Neck Disability Index. Radiologic

  7. Conduction Abnormalities and Pacemaker Implantations After SAPIEN 3 Vs SAPIEN XT Prosthesis Aortic Valve Implantation.

    Science.gov (United States)

    Husser, Oliver; Kessler, Thorsten; Burgdorf, Christof; Templin, Christian; Pellegrini, Costanza; Schneider, Simon; Kasel, Albert Markus; Kastrati, Adnan; Schunkert, Heribert; Hengstenberg, Christian

    2016-02-01

    Transcatheter aortic valve implantation is increasingly used in patients with aortic stenosis. Post-procedural intraventricular conduction abnormalities and permanent pacemaker implantations remain a serious concern. Recently, the Edwards SAPIEN 3 prosthesis has replaced the SAPIEN XT. We sought to determine the incidences of new-onset intraventricular conduction abnormalities and permanent pacemaker implantations by comparing the 2 devices. We analyzed the last consecutive 103 patients undergoing transcatheter aortic valve implantation with SAPIEN XT before SAPIEN 3 was used in the next 105 patients. To analyze permanent pacemaker implantations and new-onset intraventricular conduction abnormalities, patients with these conditions at baseline were excluded. Electrocardiograms were recorded at baseline, after the procedure, and before discharge. SAPIEN 3 was associated with higher device success (100% vs 92%; P=.005) and less paravalvular leakage (0% vs 7%; P<.001). The incidence of permanent pacemaker implantations was 12.6% (23 of 183) with no difference between the 2 groups (SAPIEN 3: 12.5% [12 of 96] vs SAPIEN XT: 12.6% [11 of 87]; P=.99). SAPIEN 3 was associated with a higher rate of new-onset intraventricular conduction abnormalities (49% vs 27%; P=.007) due to a higher rate of fascicular blocks (17% vs 5%; P=.021). There was no statistically significant difference in transient (29% [20 of 69] vs persistent 19% [12 of 64]; P=.168) left bundle branch blocks (28% [19 of 69] vs 17% [11 of 64]; P=.154) when SAPIEN 3 was compared with SAPIEN XT. We found a trend toward a higher rate of new-onset intraventricular conduction abnormalities with SAPIEN 3 compared with SAPIEN XT, although this did not result in a higher permanent pacemaker implantation rate. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  8. Simulated Prosthesis Overlay for Patient-Specific Planning of Transcatheter Aortic Valve Implantation Procedures.

    Science.gov (United States)

    Sündermann, Simon H; Gessat, Michael; Maier, Willibald; Kempfert, Jörg; Frauenfelder, Thomas; Nguyen, Thi D L; Maisano, Francesco; Falk, Volkmar

    2015-01-01

    We tested the hypothesis that simulated three-dimensional prosthesis overlay procedure planning may support valve selection in transcatheter aortic valve implantation (TAVI) procedures. Preoperative multidimensional computed tomography (MDCT) data sets from 81 consecutive TAVI patients were included in the study. A planning tool was developed, which semiautomatically creates a three-dimensional model of the aortic root from these data. Three-dimensional templates of the commonly used TAVI implants are spatially registered with the patient data and presented as graphic overlay. Fourteen physicians used the tool to perform retrospective planning of TAVI procedures. Results of prosthesis sizing were compared with the prosthesis size used in the actually performed procedure, and the patients were accordingly divided into three groups: those with equal size (concordance with retrospective planning), oversizing (retrospective planning of a smaller prosthesis), and undersizing (retrospective planning of a larger prosthesis). In the oversizing group, 85% of the patients had new pacemaker implantation. In the undersizing group, in 66%, at least mild paravalvular leakage was observed (greater than grade 1 in one third of the cases). In 46% of the patients in the equal-size group, neither of these complications was observed. Three-dimensional prosthesis overlay in MDCT-derived patient data for patient-specific planning of TAVI procedures is feasible. It may improve valve selection compared with two-dimensional MDCT planning and thus yield better outcomes.

  9. Trends in Tissue Engineering for Blood Vessels

    Science.gov (United States)

    Nemeno-Guanzon, Judee Grace; Lee, Soojung; Berg, Johan Robert; Jo, Yong Hwa; Yeo, Jee Eun; Nam, Bo Mi; Koh, Yong-Gon; Lee, Jeong Ik

    2012-01-01

    Over the years, cardiovascular diseases continue to increase and affect not only human health but also the economic stability worldwide. The advancement in tissue engineering is contributing a lot in dealing with this immediate need of alleviating human health. Blood vessel diseases are considered as major cardiovascular health problems. Although blood vessel transplantation is the most convenient treatment, it has been delimited due to scarcity of donors and the patient's conditions. However, tissue-engineered blood vessels are promising alternatives as mode of treatment for blood vessel defects. The purpose of this paper is to show the importance of the advancement on biofabrication technology for treatment of soft tissue defects particularly for vascular tissues. This will also provide an overview and update on the current status of tissue reconstruction especially from autologous stem cells, scaffolds, and scaffold-free cellular transplantable constructs. The discussion of this paper will be focused on the historical view of cardiovascular tissue engineering and stem cell biology. The representative studies featured in this paper are limited within the last decade in order to trace the trend and evolution of techniques for blood vessel tissue engineering. PMID:23251085

  10. Prosthetic Rehabilitation of a Patient with Mandibular Resection Prosthesis Using Mini Dental Implants (MDIs) – Case Report

    OpenAIRE

    Vojvodić, Denis; Čelebić, Asja; Mehulić, Ketij; Žabarović, Domagoj

    2012-01-01

    Physical disfigurement and functional impairments associated with facial trauma are a challenge to a prosthodontist, because even novel sophisticated surgical reconstructive techniques fail to provide adequate support for dental resection prosthesis. Therefore, different endosseous implants are often used as prosthesis-supporting elements. Manufacturers of dental implants have recently presented mini dental implants (MDIs) with diameter of only 1.8–2.4 mm. These implants allow very suitable p...

  11. A bar and ball attachment prosthesis over osseointegrated implants post mandibular resection

    Directory of Open Access Journals (Sweden)

    Sharad Gupta

    2016-01-01

    Full Text Available Rehabilitation of mandibular resection poses functional, esthetic, and psychological challenges. The deviation and rotation of the mandible toward the resected side leaves the patient with almost no option of chewing. This is aggravated if the patient is edentulous. The case report discussed in this article was an edentulous patient taken up with the primary goal to limit deviation toward resected side and provide a stable and retentive prosthesis to the patient. Two implants were placed anteriorly, splinted with bar and clip supported superstructure. The splinted implants with bar and clip superstructure provided the mandibular prosthesis with retention and some support. A posterior implant was also placed in the region of mandibular first molar on the left side for added support. This provided with a tripod configuration and limited the prosthetic movement of the mandibular prosthesis. This case report highlights an alternate way toward the rehabilitation of edentulous mandible post mandibular resection when surgical reconstruction may not be feasible.

  12. Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy"

    DEFF Research Database (Denmark)

    Gjørup, Hans; Nyhuus, Lone; Buhl, Jytte

    2009-01-01

    Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy". Authors; Gjoerup,H1; Nyhuus,L2; Buhl,J3. 1) Center for Oral Health in Rare Conditions, Aarhus University Hospital 2) Prosthodontic Department, the Dental School, Aarhus University 3) Department...... region. 3. At the age of 10 years a new set of dentures were made. This time the upper denture was made as an overdenture supported and retained by 4 implants and a Dolder bar. The surgical procedure included bone grafting from the anterior ramus mandibulae. The boy's subjective judgement of his oral...... health has been registered. The boy and his family experience great improvement in the functioning as well as the comfort of his prosthesis after insertion of implants. Conclusion The prosthesis for edentulous boys with HED demand several adjustments and revisions, partly due to growth of the jaws...

  13. Immediate loading of immediate mandibular implants with a full-arch fixed prosthesis: a preliminary study.

    Science.gov (United States)

    Peñarrocha, Miguel; Boronat, Araceli; Garcia, Berta

    2009-06-01

    To determine the survival of immediate dental implants with immediate loading in the partially edentulous mandible, by use of a full-arch screw-retained provisional restoration. Patients who were partially edentulous in the mandible with indications for extraction of the remaining teeth and with a minimum follow-up of 12 months after implant placement were included in the study. They were treated in chronologic order by the insertion of 6 Defcon dental implants (Impladent, Sentmenat, Spain) subjected to immediate loading (4 interforaminal and 2 posterior placements). Implants with a minimum primary stability of 60 implant stability quotient were loaded. All resin screw-retained prostheses were inserted and loaded with fully functional occlusion within 24 hours of implant placement. Eleven patients were treated with immediate implants, although 2 patients were excluded from the study for having an implant stability quotient value below 60 in at least one of the implants after surgery and did not undergo restoration with immediate loading. Fifty-four implants were placed in 9 partially edentulous patients with immediate loading with a full-arch screw-fixed prosthesis. The patients wore this provisional prosthesis during the healing period (2 months) without complication and with a high level of comfort. The survival rate of the implants was 100% at 12 months of follow-up. Immediate mandibular loading with immediate full-arch implant-supported and screw-retained restorations is a viable treatment alternative, yielding a 100% success rate in this small series of patients.

  14. Towards a Completely Implantable, Light-Sensitive Intraocular Retinal Prosthesis

    National Research Council Canada - National Science Library

    Humayun, M

    2001-01-01

    An electronic retinal prosthesis is under development to treat retinitis pigmentosa and age-related macular degeneration, two presently incurable diseases of the outer retina that afflict millions world-wide...

  15. Metallic ion release after knee prosthesis implantation: a prospective study.

    Science.gov (United States)

    Lons, Adrien; Putman, Sophie; Pasquier, Gilles; Migaud, Henri; Drumez, Elodie; Girard, Julien

    2017-12-01

    Metal-on-metal (MoM) hip replacement bearings produce metallic ions that can cause health complications. Metallic release also occurs with other materials, but data on metallic ion levels after knee arthroplasty are sparse. We postulate that knee replacement generates elevating metallic ions (chromium (Cr), cobalt (Co) and titanium (Ti)) during the first year after implantation. This ongoing prospective study included all patients who underwent the same type of knee arthroplasty between May and December 2013. Cr, Co and Ti levels were measured in whole blood at pre-operation and one-year follow-up (6 and 12 months). Clinical and radiographic data (range of motion, Oxford, International Knee Society (IKS) and satisfaction scores) were recorded. In 90 patients, preoperative Cr, Co and Ti metallic ion levels were respectively 0.45 μg/l, 0.22 μg/l, 2.94 μg/l and increased to 1.27 μg/l, 1.41 μg/l, 4.08 μg/l (p < 0.0001) at last one-year follow-up. Mean Oxford and IKS scores rose, respectively, from 45.9 (30-58) and 24.9 (12-52) to 88.3 (0-168) and 160.8 (93-200) (p < 0.001). After the implantation of knee arthroplasty, we found significant blood elevation of Cr, Co and Ti levels one year after implantation exceeding the normal values. This metallic ion release could lead to numerous effects: allergy, hypersensitivity, etc.

  16. Inflatable penile prosthesis implant length with baseline characteristic correlations: preliminary analysis of the PROPPER study.

    Science.gov (United States)

    Bennett, Nelson; Henry, Gerard; Karpman, Edward; Brant, William; Jones, LeRoy; Khera, Mohit; Kohler, Tobias; Christine, Brian; Rhee, Eugene; Kansas, Bryan; Bella, Anthony J

    2017-12-01

    "Prospective Registry of Outcomes with Penile Prosthesis for Erectile Restoration" (PROPPER) is a large, multi-institutional, prospective clinical study to collect, analyze, and report real-world outcomes for men implanted with penile prosthetic devices. We prospectively correlated co-morbid conditions and demographic data with implanted penile prosthesis size to enable clinicians to better predict implanted penis size following penile implantation. We present many new data points for the first time in the literature and postulate that radical prostatectomy (RP) is negatively correlated with penile corporal length. Patient demographics, medical history, baseline characteristics and surgical details were compiled prospectively. Pearson correlation coefficient was generated for the correlation between demographic, etiology of ED, duration of ED, co-morbid conditions, pre-operative penile length (flaccid and stretched) and length of implanted penile prosthesis. Multivariate analysis was performed to define predictors of implanted prosthesis length. From June 2011 to June 2017, 1,135 men underwent primary implantation of penile prosthesis at a total of 11 study sites. Malleable (Spectra), 2-piece Ambicor, and 3-piece AMS 700 CX/LGX were included in the analysis. The most common patient comorbidities were CV disease (26.1%), DM (11.1%), and PD (12.4%). Primary etiology of ED: RP (27.4%), DM (20.3%), CVD (18.0%), PD (10.3%), and Priapism (1.4%), others (22.6%). Mean duration of ED is 6.2¡À4.1 years. Implant length was weakly negatively correlated with White/Caucasian (r=-0.18; Pprosthesis length is negatively correlated with some ethnic groups, prostatectomy, and incontinence. Positive correlates include CV disease, preoperative stretched penile length, and flaccid penile length.

  17. Implantation of a titanium partial limb prosthesis in a white-naped crane (Grus vipio).

    Science.gov (United States)

    Rush, E Marie; Turner, Thomas M; Montgomery, Ronald; Ogburn, Anna L; Urban, Robert M; Sidebothum, Chris; LaVasser, Andrew

    2012-09-01

    A female white-naped crane (Grus vipio) was presented with an open, oblique fracture of the distal right tarsometatarsus and concomitant vascular and nerve damage. Conventional fracture fixation repairs failed, which led to implantation of a custom titanium limb prosthesis. After subsequent revisions with 2 different prosthetic devices, limb function was ultimately restored but a later yolk embolism caused a circulatory compromise in the opposite leg, which necessitated euthanasia. Histopathologic results revealed limited ingrowth of bone into the porous coated implant, which indicated that a limb prosthesis may provide salvage for long-legged, heavy-bodied birds with fractures of the tarsometatarsus.

  18. Self-retaining magnetic implant: A novel design of orbital prosthesis for the exenterated orbit.

    Science.gov (United States)

    Mak, Shiu Ting; Chan, Timmy K C; Li, Kenneth K W

    2017-12-01

    Orbital exenteration can lead to significant disfigurement causing considerable functional, cosmetic and psychological disturbances to the patient. Orbital prosthesis is important for the patient's cosmetic and psychological rehabilitation. A 49-year-old man received orbital exenteration and postoperative radiotherapy for malignant orbital carcinoma. In view of uncertain suitability and survival of osseointegrated implant in his case, a novel design of ocular implant consisting of a self-retaining magnetic spring retainer and a coupling silicone prosthesis was used. This novel design was shown to provide the patient with ease of use, good cosmetic outcome and better quality of life.

  19. Design concepts of a removable partial dental prosthesis with implant-supported abutments.

    Science.gov (United States)

    Yeung, Stephanie; Chee, Winston W L; Torbati, Arman

    2014-08-01

    A clinical report is presented that describes the restoration of a severe anterior maxillary ridge defect and pneumatized sinuses with a rotation-path partial removable dental prosthesis and implant-supported abutments. Other treatment options were considered and rejected based on patient preferences and limitations, which included avoiding invasive surgeries. The principles of integrating fixed and removable prosthesis design were applied. However, the clasp design was modified to take into account the direct bone-to-implant contact of the abutments. An esthetic and functional outcome was obtained without any overly invasive surgery. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  20. Epidemiology of Implant Mortality Disparity Among Intraoral Positions and Prosthesis Types.

    Science.gov (United States)

    Choi, Yong-Geun; Eckert, Steven E; Kang, Kyung Lhi; Shin, Sang-Wan; Kim, Young-Kyun

    To examine the disparity of single-crown implant failure with a similar loss of the splinted prosthesis in differing anatomical locations while controlling for other demographic and clinical variables that may confound the relationship between prosthesis types and implant loss. A multicenter retrospective cohort study was designed to include patients treated with dental implants from 2003 to 2014. The variables included age, sex, systemic disease, bone graft, implant placement date, position of dental implant, length of dental implant, diameter of dental implant, loading time, type of prosthesis, type of opposing occlusion, latest check date, and survival or loss of the dental implant. The demographic and clinical variables' influence on the survival of dental implants was estimated by the Kaplan-Meier method. The position and diameter were adjusted for the accurate estimation of the relationship between the prosthesis type and survival of the dental implant with the Cox proportional hazard method. A total of 1,151 dental implants from 403 patients were ascertained. After adjusting for the confounding effect of position and diameter, single-crown prostheses were 38.1 (95% CI: 15.1-118) times more likely to be lost than the connected-type prostheses. For single-crown implants, the waiting time for osseointegration before loading was the highest for the maxillary molar position and the lowest for the mandibular molar position (P < .0001), while the most frequent implant loss occurred in the maxillary anterior area, and the second frequent area was the maxillary molar position; the lowest occurrence of implant loss was for the mandibular molar position. This disparity was statistically significant (P = .0271). Despite the high survival rates of endosseous implants as a whole, since the variation of implant loss was observed among the different anatomical positions for single-crown implants, special attention has to be given to the maxillary anterior and maxillary

  1. A wide-field suprachoroidal retinal prosthesis is stable and well tolerated following chronic implantation.

    Science.gov (United States)

    Villalobos, Joel; Nayagam, David A X; Allen, Penelope J; McKelvie, Penelope; Luu, Chi D; Ayton, Lauren N; Freemantle, Alexia L; McPhedran, Michelle; Basa, Meri; McGowan, Ceara C; Shepherd, Robert K; Williams, Chris E

    2013-05-01

    The safety of chronic implantation of a retinal prosthesis in the suprachoroidal space has not been established. This study aimed to determine the safety of a wide-field suprachoroidal electrode array following chronic implantation using histopathologic techniques and electroretinography. A platinum electrode array in a wide silicone substrate was implanted unilaterally in the suprachoroidal space in adult cats (n = 7). The lead and connector were tunneled out of the orbit and positioned subcutaneously. Postsurgical recovery was assessed using fundus photography and electroretinography (ERG). Following 3 months of passive implantation, the animals were terminated and the eyes assessed for the pathologic response to implantation. The implant was mechanically stable in the suprachoroidal space during the course of the study. The implanted eye showed a transient increase in ERG response amplitude at 2 weeks, which returned to normal by 3 months. Pigmentary changes were observed at the distal end of the implant, near the optic disc. Histopathologic assessment revealed a largely intact retina and a thin fibrous capsule around the suprachoroidal implant cavity. The foreign body response was minimal, with sporadic presence of macrophages and no active inflammation. All implanted eyes were negative for bacterial or fungal infections. A midgrade granuloma and thick fibrous buildup surrounded the extraocular cable. Scleral closure was maintained in six of seven eyes. There were no staphylomas or choroidal incarceration. A wide-field retinal prosthesis was stable and well tolerated during long-term suprachoroidal implantation in a cat model. The surgical approach was reproducible and overall safe.

  2. Self and partner satisfaction rates after 3 part inflatable penile prosthesis implantation

    Directory of Open Access Journals (Sweden)

    Abdulmuttalip Simsek

    2014-09-01

    Full Text Available Objective: To evaluate and present satisfaction rates of our patients and their partners after 3 part inflatable penile prosthesis implantation. Materials and methods: We searched our hospital electronic data for patients who underwent inflatable penile prosthesis implantation between January 2008 and July 2013. Computer and archived file data were used to get information and reach the patients. We made telephone calls to patients and asked questionnaires about self and partner satisfaction rates. Results: 36 patients underwent prosthesis implantation during the 5 year period. We were able to reach by telephone call 18 of them. The mean age of 18 patients was 55.7 ± 9.4 years and mean body mass index was 24.6 ± 2.1 kg/m2. The etiology was diabetes mellitus on 14 (77.8% and radical pelvic surgery on 4 (22.2% patients. 14 of 18 patients had penile Doppler ultrasound test. Doppler ultrasound demonstrated venous insufficiency in 8 and arterial insufficiency in 6 patients. Mean time from implantation to study was 20.8 ± 13.9 months. Out of 18 patients 2 had prosthesis removal operation because of infection in one patient and perforation in the other. Satisfaction rate was 88.9%, and recommendation rate was 94.4%. Causes of dissatisfaction were pain in one patient and insufficient rigidity plus shortening of the penis in the other one. Partner satisfaction rate was 94.4%. Conclusion: Penile Prosthesis Implantation (PPI is the gold standard treatment of erectile dysfunction (ED irresponsive to medical treatment. Infection and mechanical failure rates are going to be less according to the improvements in synthetic materials and coverings of the prosthesis, so patient and partner satisfaction rates will be higher.

  3. Self and partner satisfaction rates after 3 part inflatable penile prosthesis implantation.

    Science.gov (United States)

    Simsek, Abdulmuttalip; Kucuktopcu, Onur; Ozgor, Faruk; Ozkuvanci, Unsal; Baykal, Murat; Sarilar, Omer; Gurbuz, Zafer Gokhan

    2014-09-30

    To evaluate and present satisfaction rates of our patients and their partners after 3 part inflatable penile prosthesis implantation. We searched our hospital electronic data for patients who underwent inflatable penile prosthesis implantation between January 2008 and July 2013. Computer and archived file data were used to get information and reach the patients. We made telephone calls to patients and asked questionnaires about self and partner satisfaction rates. 36 patients underwent prosthesis implantation during the 5 year period. We were able to reach by telephone call 18 of them. The mean age of 18 patients was 55.7 ± 9.4 years and mean body mass index was 24.6 ± 2.1 kg/m2. The etiology was diabetes mellitus on 14 (77.8%) and radical pelvic surgery on 4 (22.2%) patients. 14 of 18 patients had penile Doppler ultrasound test. Doppler ultrasound demonstrated venous insufficiency in 8 and arterial insufficiency in 6 patients. Mean time from implantation to study was 20.8 ± 13.9 months. Out of 18 patients 2 had prosthesis removal operation because of infection in one patient and perforation in the other. Satisfaction rate was 88.9%, and recommendation rate was 94.4%. Causes of dissatisfaction were pain in one patient and insufficient rigidity plus shortening of the penis in the other one. Partner satisfaction rate was 94.4%. Penile Prosthesis Implantation (PPI) is the gold standard treatment of erectile dysfunction (ED) irresponsive to medical treatment. Infection and mechanical failure rates are going to be less according to the improvements in synthetic materials and coverings of the prosthesis, so patient and partner satisfaction rates will be higher.

  4. Identification of the critical level of implantation of an osseointegrated prosthesis for above-knee amputees.

    Science.gov (United States)

    Andrango Castro, Elder Michael; Konvickova, Svatava; Daniel, Matej; Horak, Zdenek

    2017-11-01

    The aim of our study was to identify potential critical levels of implantation of an osseointegrated prosthesis for above-knee amputees. The implant used was the OPRA system. It was inserted in the femur at four different amputation heights, characterized by their residual limb ratios (0.299, 0.44, 0.58 and 0.73). The stress and strain distribution was evaluated in the bone-implant system during walking, considering a body mass of 100 kg. Considerably high stimulus (11,489 με) in the tissue near the tip was found at the highest implantation level. All models presented small non-physiologic stress values in the tissue around the implant. The results revealed that the implantation level has a decisive effect on bone-implant performance. Mainly, the analysis indicates adverse biomechanical conditions for implantations in very short residual limbs.

  5. Immediate loading of definitive implants in the edentulous mandible using a fixed provisional prosthesis: The denture conversion technique.

    Science.gov (United States)

    Misch, Craig M

    2004-09-01

    This article presents a clinical technique for immediate implant loading in the completely edentulous mandible. The protocol recommends the placement of 4 to 5 root-form implants in the anterior mandible between the mental foramina. Upon insertion the implants must have favorable primary stability. Abutments are added to the implants and the patient's lower denture is converted into an immediate load provisional fixed prosthesis. The denture conversion technique has been shown to provide predictable results for immediate implant loading in the edentulous mandible. The final prosthesis is fabricated upon integration of the implants in 3 months. The denture conversion technique offers several advantages because it may be used with most commercially available implant systems and it incorporates conventional implant components. Guidelines for patient selection, presurgical preparation, implant surgery, prosthesis fabrication, and postoperative care are reviewed.

  6. A finite element analysis of two different dental implants: stress distribution in the prosthesis, abutment, implant, and supporting bone.

    Science.gov (United States)

    Quaresma, Sergio E T; Cury, Patricia R; Sendyk, Wilson R; Sendyk, Claudio

    2008-01-01

    This study evaluates the influence of 2 commercially available dental implant systems on stress distribution in the prosthesis, abutment, implant, and supporting alveolar bone under simulated occlusal forces, employing a finite element analysis. The implants and abutments evaluated consisted of a stepped cylinder implant connected to a screw-retained, internal, hexagonal abutment (system 1) and a conical implant connected to a solid, internal, conical abutment (system 2). A porcelain-covered, silver-palladium alloy was used as a crown. In each case, a simulated, 100-N vertical load was applied to the buccal cusp. A finite element model was created based on the physical properties of each component, and the values of the von Mises stresses generated in the prosthesis, abutment, implant, and supporting alveolar bone were calculated. In the prostheses, the maximum von Mises stresses were concentrated at the points of load application in both systems, and they were greater in system 1 (148 N/mm2) than in system 2 (55 N/mm2). Stress was greater on the abutment of system 2 than of system 1 on both the buccal (342 N/mm2 x 294 N/mm2) and lingual (294 N/mm2 x 148 N/ mm2) faces. Stress in the cortical, alveolar bone crest was greater in system 1 than in system 2 (buccal: 99.5 N/mm2 x 55 N/mm2, lingual: 55 N/mm2 x 24.5 N/mm2, respectively). Within the limits of this investigation, the stepped cylinder implant connected to a screw-retained, internal hexagonal abutment produces greater stresses on the alveolar bone and prosthesis and lower stresses on the abutment complex. In contrast, the conical implant connected to a solid, internal, conical abutment furnishes lower stresses on the alveolar bone and prosthesis and greater stresses on the abutment.

  7. Decreased extension gap and valgus alignment after implantation of total knee prosthesis in primary varus knees.

    Science.gov (United States)

    Minoda, Yukihide; Nakagawa, Shigeru; Sugama, Ryo; Ikawa, Tessyu; Noguchi, Takahiro; Hirakawa, Masashi; Matsui, Yoshio; Nakamura, Hiroaki

    2016-11-01

    It was hypothesised that implantation of a total knee prosthesis may change the size and shape of the joint gap. To test this hypothesis, a tensor device was used which was specifically designed to reproduce the conditions before and after implantation, including attachment of the polyethylene insert trial. This study aimed to compare the joint gaps before and after implantation of a total knee prosthesis using this new tensor device. A total of 259 primary varus knees were included in this study. Knees were exposed using a medial parapatellar approach, and the anterior and posterior cruciate ligaments were resected. After the trial reduction, the intraoperative joint gap kinematics was measured using the tensor device. Implantation of a total knee prosthesis decreased the size of the extension joint gap and made it valgus, but did not influence the size or shape of the flexion joint gap. The present findings suggest that the classical gap technique, which creates equal and rectangular extension and flexion joint gaps in the bone cutting surface, results in an imbalance between the extension and flexion joint gaps after implantation. To achieve equal and rectangular extension and flexion joint gaps after implantation, the prepared extension joint gap should be about 2 mm larger than the flexion joint gap and slightly varus before implantation in primary varus knees. Therapeutic study, Level II.

  8. Fabrication of an Implant-Supported Orbital Prosthesis with Bar-Magnetic Attachment: A Clinical Report.

    Science.gov (United States)

    Aalaei, Shima; Abolhassani, Abolhassan; Nematollahi, Fatemeh; Beyabanaki, Elaheh; Mangoli, Amir Ali

    2015-12-01

    Implant-supported craniofacial prostheses are made to restore defective areas in the face and cranium. This clinical report describes a technique for fabrication of an orbital prosthesis with three adjacent implants in the left lateral orbital rim of a 60-year-old woman. Selection of appropriate attachment system (individual magnetic abutments versus bar-clip attachment) for implant-supported orbital prostheses depends upon the position of implants. Bar-magnetic attachment has been selected as the retention mechanism in the present case.

  9. Prosthetic Consideration in Implant-supported Prosthesis: A Review of Literature.

    Science.gov (United States)

    Gowd, Manga Snigdha; Shankar, Thatapudi; Ranjan, Rajeev; Singh, Arpita

    2017-06-01

    Modern dentistry has changed tremendously with implant therapy. For the successful implant therapy, making a proper treatment plan considering both surgical and prosthetic part in mind is the key of success. Often practitioners tend to create a treatment plan overlooking the basic principles of prosthetic part. This present review has discussed various prosthetic consideration of implant-supported prosthesis. A step-by-step detailed prosthetic option with their indications has been discussed to help all dental implant practitioners in making of an optimal treatment plan for each case.

  10. Prosthesis

    Science.gov (United States)

    A prosthesis is a device designed to replace a missing part of the body or to make a part of the body work better. Diseased or missing eyes, arms, hands, legs, or joints are commonly replaced by prosthetic devices. False teeth are known as dental prostheses. ...

  11. Pre-surgical Provisional Prosthesis for Immediate Non-occlusal-loaded Flapless Implant

    OpenAIRE

    Inbarajan, Athiban; Banu, Fathima; TV, Padmanabhan; Kumar, Anand; Seenivasan, Madhan

    2017-01-01

    A 49-year-old patient reported for immediate replacement of missing maxillary anterior teeth with implant-retained prosthesis. Elevation of flap alters the mucosal level, causes discomfort, and delays the restorative procedure. To maintain the esthetics, flapless surgery was planned. Since placement of an implant is pre-planned in a predetermined site, fabrication of the prostheses before commencement of the surgery, especially when replacing the teeth in the anterior region, could be a viabl...

  12. [Application of spark erosion technology in manufacture of implant prosthesis].

    Science.gov (United States)

    Cui, H Y; DI, P; Li, J H; Lin, Y; Liu, R R

    2015-04-18

    To evaluate the influence of the implant-supported porcelain bridges made from non-precious metals using spark erosion techniques, and to discuss the feasibility and details of making the implant restoration by spark erosion technique. The study included 12 patients (9 males and 3 females) with 92 units implant-supported non-precious porcelain bridge from Sep. 2011 to Feb. 2013. All the patients received implant treatment in Department of Oral Implantology, Peking University School and Hospital of Stomatology. The total of 52 implants, were from Nobel Biocare implant system, Camlog implant system and Ankylos implant system. The implant analogs were connected in sequence with a copper wire to guarantee conductivity. The implant electrodes represented one electrode and the superstructure the other. During spark-erosion machining, the cast holding the implant electrodes and the prosthetic framework were moved toward one another, causing an electrical erosion of the protruding elements. After the spark-erosion machining, the minimum gap between the framework and abutment was 0.21 mm, which was two units bridge. The maximum was 2.59 mm, which was 11 units bridge with 6 implants. The average gap was 0.68 mm. After the spark-erosion machining, the bridge fitted well with the passive position stability. The method of making implant-supported non-precious porcelain bridge reduces costs on patients. Spark erosion has the potential to provide implant framework with an excellent fit. The patients are satisfied with the clinical results.

  13. A novel knee prosthesis model of implant-related osteo- myelitis in rats

    DEFF Research Database (Denmark)

    Søe, Niels H.; Jensen, Nina Vendel; Nürnberg, Birgit Meinecke

    2012-01-01

    There have been numerous reports of animal models of osteomyelitis. Very few of these have been prosthesis models that imitate human conditions. We have developed a new rat model of implant-related osteomyelitis that mimics human osteomyelitis, to investigate the pathology of infection after...

  14. Automated measurement of retinal blood vessel tortuosity

    Science.gov (United States)

    Joshi, Vinayak; Reinhardt, Joseph M.; Abramoff, Michael D.

    2010-03-01

    Abnormalities in the vascular pattern of the retina are associated with retinal diseases and are also risk factors for systemic diseases, especially cardiovascular diseases. The three-dimensional retinal vascular pattern is mostly formed congenitally, but is then modified over life, in response to aging, vessel wall dystrophies and long term changes in blood flow and pressure. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e. how curved or kinked a blood vessel, either vein or artery, appears along its course. We developed a new quantitative metric for vascular tortuosity, based on the vessel's angle of curvature, length of the curved vessel over its chord length (arc to chord ratio), number of curvature sign changes, and combined these into a unidimensional metric, Tortuosity Index (TI). In comparison to other published methods this method can estimate appropriate TI for vessels with constant curvature sign and vessels with equal arc to chord ratios, as well. We applied this method to a dataset of 15 digital fundus images of 8 patients with Facioscapulohumeral muscular dystrophy (FSHD), and to the other publically available dataset of 60 fundus images of normal cases and patients with hypertensive retinopathy, of which the arterial and venous tortuosities have also been graded by masked experts (ophthalmologists). The method produced exactly the same rank-ordered list of vessel tortuosity (TI) values as obtained by averaging the tortuosity grading given by 3 ophthalmologists for FSHD dataset and a list of TI values with high ranking correlation with the ophthalmologist's grading for the other dataset. Our results show that TI has potential to detect and evaluate abnormal retinal vascular structure in early diagnosis and prognosis of retinopathies.

  15. Effect of oral mucosa transplantation in the treatment of severe contracted conjunctival sac after ocular prosthesis implantation

    Directory of Open Access Journals (Sweden)

    Li-Li Dong

    2014-12-01

    Full Text Available AIM:To observe the clinic effect of oral mucosa transplantation in the treatment of severe contracted conjunctival sac after ocular prosthesis implantation.METHODS: Thirty-three cases(33 eyeswith globe disorders and severe contracted conjunctval sac were operated ocular prosthesis implantation firstly, and conjunctival sac plasty using oral mucosa after 6mo. RESULTS: Thirty-one cases were successful, no complications appeared. One case had primary ptosis and 1 case had recurrent conjunctival sac contracture.CONCLUSION: It is recognised that the methods of oral mucosa transplantation in severe contracted conjunctival sac after ocular prosthesis implantation are effective on those cases.

  16. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

  17. Maintenance of bone mineral density after implantation of a femoral neck hip prosthesis.

    Science.gov (United States)

    Decking, Ralf; Rokahr, Christoph; Zurstegge, Matthias; Simon, Ulrich; Decking, Jens

    2008-01-31

    Stress shielding of the proximal femur has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to investigate the changes of bone-mineral density in the proximal femur and the clinical outcome after implantation of a short femoral-neck prosthesis. We prospectively assessed the clinical outcome and the changes of bone mineral density of the proximal femur up to one year after implantation of a short femoral neck prosthesis in 20 patients with a mean age of 47 years (range 17 to 65). Clinical outcome was assessed using the Harris Hip Score. The WOMAC was used as a patient-relevant outcome-measure. The bone mineral density was determined using dual energy x-ray absorptiometry, performed 10 days, three months and 12 months after surgery. The Harris Hip Score improved from an average preoperative score of 46 to a postoperative score at 12 months of 89 points, the global WOMAC index from 5,3 preoperatively to 0,8 at 12 months postoperatively. In contrast to conventional implants, the DEXA-scans overall revealed a slight increase of bone mineral density in the proximal femur in the 12 months following the implantation. The short femoral neck stem lead to a distinct bone reaction. This was significantly different when compared to the changes in bone mineral density reported after implantation of conventional implants.

  18. [Dorsal sagittal knee joint stability after endoprosthetic knee arthroplasty : Influence of preoperative joint stability and the type of implanted prosthesis].

    Science.gov (United States)

    Schulze, A; Gärtner, M; Scharf, H-P

    2015-03-01

    Anterior knee pain is a known complication after implantation of a prosthesis and a possible reason is a posterior knee joint instability; however, the influence on postoperative stability is just as unknown as the possible influence of the type of prosthesis on postoperative stability. This study investigated two possible preoperative and intraoperative influencing factors by determination of the preoperative joint stability and type of prosthesis.

  19. The Metal-Zirconia Implant Fixed Hybrid Full-Arch Prosthesis: An Alternative Technique for Fabrication.

    Science.gov (United States)

    Stumpel, Lambert J; Haechler, Walter

    2018-03-01

    The metal-resin hybrid full-arch prosthesis has been a traditionally used type of restoration for full-arch implant fixed dentures. A newer development has centered around the use of monolithic zirconia or zirconia veneered with porcelain. Being a ceramic, zirconia has the potential for fracture. This article describes a technique that utilizes a metal substructure to support a chemically and mechanically resinbonded shell of zirconia. The workflow is discussed, ranging from in-office master cast fabrication to the CAD/ CAM production of the provisional and the definitive metal-zirconia prosthesis. The article also highlights the advantages and disadvantages of various materials used for hybrid prostheses.

  20. Incidence of Prosthetic Complications associated with Implant-borne Prosthesis in a Sleep Disorder Center.

    Science.gov (United States)

    Suneel, Venkatesh B; Kotian, Santhosh; Jujare, Ravikanth H; Shetty, Adarsh K; Nidhi, Sneh; Grover, Shehkar

    2017-09-01

    Obstructive sleep apnea (OSA) is one of the common prevalent conditions present worldwide. The process of abnormal habits related to clenching and grinding of teeth is referred to as bruxism and is characterized under the heading of parafunctional activity of the masticatory system. Osseointegrated dental implants represent advancements in the field of odontology. Despite its high success rate, failure and complications are often associated with dental implant treatment due to a number of factors. Hence, we aimed for the present study to assess the incidence of prosthetic complications in patients rehabilitated with implant-borne prosthesis in a sleep disorder unit. The present study included the assessment of all the patients who underwent prosthetic rehabilitation by dental implants. An experienced registered prosthodontist was given duty for examination of all the cases from the record file data. Prosthetic complications in the patients were identified using photographs, radiographs, and all other relevant data of the patients obtained from the record files. All types of complications and other factors were recorded separately and analyzed. While correlating the prosthetic complications in OSA patients grouped based on number of dental implants, nonsignificant results were obtained. Significant correlation was observed while comparing the prosthetic complications divided based on type of prosthesis. Fracture of the porcelain was observed in four and eight cases respectively, of screwed and cemented dental implant cases. Some amount of significant correlation existed between the incidences of prosthetic complications and OSA. Proper history of the patients undergoing dental implant procedures should be taken to avoid failure.

  1. A comparison of tumor prosthesis implantation and pasteurized autograft-prosthesis composite for proximal tibial tumor.

    Science.gov (United States)

    Song, Won Seok; Cho, Wan Hyeong; Jeon, Dae-Geun; Kong, Chang-Bae; Duo, Jian; Lee, Soo-Yong

    2012-07-01

    Although previous reports on composite biologic reconstruction in the proximal tibial location vary, we hypothesized that this type of reconstruction may reduce the late infection rate and have advantages in terms of longevity by restoring bone stock. Primary analysis addressed differences between 62 tumor prosthesis (TP) and 25 pasteurized autograft-prosthesis composite (PPC) reconstructions in terms of survival rates, functional outcomes, and temporal patterns of infection. The 10-year survival rates of the TP and PPC groups were 73.9 ± 11.7 and 68.7 ± 20.1 %, respectively (P = 0.64). Reconstructive failure occurred in 16 (25.8 %) in the TP and in 7 (28 %) in the PPC group. The cause of failures in the TP group was infection (16), whereas those of PPC group were infection (5), loosening (1), and local recurrence (1). The mean functional scores of TP (52) and PPC (20) patients that maintained a mobile joint were 24.2 (81 %) and 25.1 (83.6 %), respectively. Infection rates in the two groups were similar (P = 0.328), but infections occurred earlier in the PPC group (P = 0.011). This comparative study suggests composite biological reconstruction shows a comparable long-term survival rate to TP reconstruction; however, the composite method has a tendency to a lower rate of late infection.

  2. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    Science.gov (United States)

    GRANDO, Antônio Francisco; REZENDE, Carlos Eduardo Edwards; SOUSA, Edson Antônio Capello; RUBO, José Henrique

    2014-01-01

    Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application). Results The results showed that both variables had influence on the studied factors (deformation by compression and tension). Conclusion The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant. PMID:25025562

  3. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    Directory of Open Access Journals (Sweden)

    Antônio Francisco GRANDO

    2014-06-01

    Full Text Available Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives: The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application. Results: The results showed that both variables had influence on the studied factors (deformation by compression and tension. Conclusion: The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant.

  4. Fabricating a Soft Liner-Retained Implant-Supported Palatal Lift Prosthesis for an Edentulous Patient: A Case Report

    Directory of Open Access Journals (Sweden)

    Omid Savabi

    2012-01-01

    Full Text Available This case report describes fabrication of a palatal lift prosthesis for a quadriplegic edentulous 30-year-old male with past head traumatic injury. We constructed an implant supported bar and used a soft-lining material for the maxillary palatal lift prosthesis to minimize the possibility of implant overloading and also provide a less complex and less expensive procedure for this patient.

  5. Penile prosthesis implantation in Chinese patients with severe erectile dysfunction: 10-year experience

    Science.gov (United States)

    Song, Wei-Dong; Yuan, Yi-Ming; Cui, Wan-Shou; Wu, Alex K; Zhu, Yi-Chen; Liu, Jing; Wang, Lin; Bai, Guang-Yi; Peng, Jing; Zhang, Zhi-Chao; Gao, Bing; Guo, Ying-Lu; Lue, Tom F; Xin, Zhong-Cheng

    2013-01-01

    We retrospectively evaluated the clinical outcome of penile prosthesis implantation (PPI) in Chinese patients with severe erectile dysfunction (SED). From July 2000 to December 2011, 224 patients (mean age: 35.9±11.8 years, range: 20–75 years) with SED underwent PPI by experienced surgeon according to standard PPI procedure at our centre. A malleable prosthesis (AMS 650) was implanted in 45 cases (20.1%), and a three-piece inflatable prosthesis (AMS 700 CXM or AMS 700 CXR) was implanted in 179 cases (79.9%). Surgical outcomes, including postoperative complications, clinical efficacy and couple satisfaction, were evaluated over than 6 months postoperatively using medical record abstraction, IIEF-5, quality of life (QoL) scores, and the patient/partner sexual satisfaction score proposed by Bhojwani et al. Of the 224 patients eligible for the study, 201 subjects (89.7%) completed follow-up. All of patients could perform sexual intercourse post PPI with the mean postoperative IIEF-5 and QoL scores were 20.02±2.32 and 5.28±0.76, respectively, which were significantly improved compared with the preoperative scores (6.29±1.5 and 2.13±0.84, Preported by 178 men (88.6%), and overall satisfaction with the PPI surgery was reported by 89.0% of men and 82.5% of partners. Patient satisfaction in the three-piece inflatable prosthesis group was higher than in the malleable prosthesis group (P<0.05). Satisfaction, however, between the types of prostheses, did not differ in the partner survey. PPI is a safe and effective treatment option for Chinese patients with SED and experienced surgeon perform PPI according to standard PPI procedure could reduce the postoperative complications of PPI and could improve patient satisfaction ratio and QoL. PMID:23872664

  6. Horizontal alveolar ridge expansion followed by immediate placement of implants and rehabilitation with zirconia prosthesis

    Directory of Open Access Journals (Sweden)

    Tatiana Miranda Deliberador

    2017-01-01

    Full Text Available In recent years, there have been a growing number of procedures involving dental implants. Most cases, though, are characterized by bone atrophy, especially horizontal atrophy. This clinical case aims to report a technique for the expansion of the horizontal alveolar ridge. A longitudinal fracture was created in the alveolar ridge to expand the bone, followed by immediate insertion of dental implants along with a particulate allogeneic bone graft. Eight implants were placed in the maxilla, and after 12 months, a surgical reopening was performed, along with rehabilitation with a protocol-type prosthesis, for which a zirconia infrastructure was made. The patient was observed during a 10-month follow-up period in which an effective osseointegration of all implants was achieved as a result of such a technique. The split-crest technique followed by the immediate placement of implants and a particulate allogeneic bone graft proved to be effective, with a predictable osseointegration.

  7. Horizontal alveolar ridge expansion followed by immediate placement of implants and rehabilitation with zirconia prosthesis.

    Science.gov (United States)

    Deliberador, Tatiana Miranda; Verbicaro, Thalyta; Minerva, Leonel; Scariot, Rafaela; Giovanini, Allan Fernando; Zielak, João César

    2017-01-01

    In recent years, there have been a growing number of procedures involving dental implants. Most cases, though, are characterized by bone atrophy, especially horizontal atrophy. This clinical case aims to report a technique for the expansion of the horizontal alveolar ridge. A longitudinal fracture was created in the alveolar ridge to expand the bone, followed by immediate insertion of dental implants along with a particulate allogeneic bone graft. Eight implants were placed in the maxilla, and after 12 months, a surgical reopening was performed, along with rehabilitation with a protocol-type prosthesis, for which a zirconia infrastructure was made. The patient was observed during a 10-month follow-up period in which an effective osseointegration of all implants was achieved as a result of such a technique. The split-crest technique followed by the immediate placement of implants and a particulate allogeneic bone graft proved to be effective, with a predictable osseointegration.

  8. Refabrication of an implant-retained auricular prosthesis using clip attachment pickup technique

    Directory of Open Access Journals (Sweden)

    Sanketh Kethireddy

    2017-01-01

    Full Text Available Increased patient acceptance and widespread use have led to a greater demand for refabrication of existing maxillofacial prostheses exhibiting wear and tear. Refabricating an osseointegrated implant-retained silicone auricular prosthesis on the existing Hader bar is a challenging task if it is performed without removing it. Therefore, an attachment level impression method is utilized for the refabrication of a new prosthesis on an existing Hader bar framework without removing it from the patient's defect. This case report discusses a modification of the Mahidol University technique. This modification provides a simple, speedy, and convenient method through which the relation between the metal framework and attachments could be obtained precisely. This precision allowed for easy fabrication of the acrylic housing, which in turn results in better adaptation of the auricular prosthesis to the patient's face. Therefore, this technique offers advantages to both the prosthetist in fabrication and the patient in facilitating him continue to wear his existing implant-retained prosthesis during refabrication process.

  9. Suprapubic cystostomy for the management of urethral injuries during penile prosthesis implantation.

    Science.gov (United States)

    Anele, Uzoma A; Le, Brian V; Burnett, Arthur L

    2014-12-01

    Urethral injury is an uncommon surgical complication of penile prosthesis (PP) surgery. Conventional dogma requires abortion of the procedure if the adjacent corporal body is involved or delayed implantation to avert device infection associated with urinary extravasation. Besides the setback of the aborted surgery, this management approach also presents the possible difficulty of encountering corporal fibrosis at the time of reoperation. We report an approach using primary urethral repair and temporary suprapubic cystostomy for the management of incidental urethral injuries in a cohort of patients allowing for successful completion of unaborted PP implantation. We performed a retrospective analysis of all patients receiving PPs from 1990 to 2014 in which incidental urethral injuries were repaired and PP implantation was completed with suprapubic cystostomy (suprapubic tube [SPT] insertion). After allowing for urethral healing and urinary diversion via SPT for 4-8 weeks, the PP was activated. Successful management was determined by the absence of perioperative complications within 6 months of implantation. We identified four cases, all receiving inflatable PPs, managed with temporary suprapubic cystostomy. These patients sustained urethral injuries during corporal dissection (one patient), corporal dilation (one patient), and penile straightening (two patients). All patients were managed safely and successfully. Primary urethral repair followed by temporary suprapubic cystostomy offers a surgical approach to complete PP implantation successfully in patients who sustain urethral injury complications, particularly for complex PP surgeries. Anele UA, Le BV, and Burnett AL. Suprapubic cystostomy for the management of urethral injuries during penile prosthesis implantation.

  10. A Standardized Method for Measuring Internal Lung Surface Area via Mouse Pneumonectomy and Prosthesis Implantation.

    Science.gov (United States)

    Liu, Zhe; Fu, Siling; Tang, Nan

    2017-07-26

    Pulmonary morphology, physiology, and respiratory functions change in both physiological and pathological conditions. Internal lung surface area (ISA), representing the gas-exchange capacity of the lung, is a critical criterion to assess respiratory function. However, observer bias can significantly influence measured values for lung morphological parameters. The protocol that we describe here minimizes variations during measurements of two morphological parameters used for ISA calculation: internal lung volume (ILV) and mean linear intercept (MLI). Using ISA as a morphometric and functional parameter to determine the outcome of alveolar regeneration in both pneumonectomy (PNX) and prosthesis implantation mouse models, we found that the increased ISA following PNX treatment was significantly blocked by implantation of a prosthesis into the thoracic cavity 1 . The ability to accurately quantify ISA is not only expected to improve the reliability and reproducibility of lung function studies in injured-induced alveolar regeneration models, but also to promote mechanistic discoveries of multiple pulmonary diseases.

  11. Evaluation of Short and Regular Implants after Prosthesis Placement in the Mandible: A Nonrandomized Controlled Clinical Trial.

    Science.gov (United States)

    de Molon, Rafael S; Lages, Frederico S; Rivera, Carolina P; de Souza Faloni, Ana P; Margonar, Rogerio; Queiroz, Thallita P

    2017-12-01

    The aim of this nonrandomized controlled preliminary clinical trial was to compare treatment using short and conventional implants in the posterior region of the mandible after prosthesis installation by means of clinical, resonance frequency, and radiographic analyses. A total of 10 patients with 40 dental implants already installed were included in this study. Four implants were installed for each subject, in which the length of the implants (short and conventional) was distributed according to the reminiscent alveolar bone in the left and right side of the mandible. All implants received splinted prosthesis after the osseointegration period. Analyses were performed immediately after prosthesis installation (T1), and 3 (T2) and 6 months (T3) after prosthesis placement. The 6-month survival and success rates were 100% for the short and conventional implants. Probing depths (PDs) after 6 months did not show statistical differences between short and conventional implants. All groups showed mean implant stability quotient (ISQ) values above 60 in all periods evaluated, demonstrating great implant stability, and no differences were found between groups at T3. Radiographic measurements showed an increased bone loss for conventional implants compared with short implants in all the three periods evaluated. Our findings suggest that treatment of resorbed posterior regions in the mandible with shorter dental implants is as reliable as treatment with conventional implants after 6 months of splinted prosthesis installation. Short implants might be considered a predictable treatment alternative to bone augmentation or extensive surgical techniques in regions of restricted vertical bone height in the posterior region of the mandible.

  12. Clinical Assessment of “All in One” Framework for Partial Implant - Supported Prosthesis

    OpenAIRE

    Vinuela, A.; de Parga, J.Martinez Vazquez; Del Rio, Highsmith J.

    2002-01-01

    INTRODUCTION: Restoration by implant-supported prosthesis seems to be a current option in the treatment of partially edentulous patients. Its success depends on the passive fit of the framework. Searching for new manufacturing materials and techniques to solve these problems, dental companies, combining clinical and experimental research, offer different solutions, such as Nobel Biocare, the “all in one” system, which is a framework designed by CAD/CAM. AIM OF PRESENTATION: Clinical and ra...

  13. Surgical and prosthodontic consequences of inadequate treatment planning for fixed implant-supported prosthesis in the edentulous mandible.

    Science.gov (United States)

    Bidra, Avinash S

    2010-10-01

    Treatment planning for mandibular fixed implant-supported prostheses requires close communication between surgeons and restorative dentists. Improper implant positioning can result in significant difficulty for patient comfort and fabrication of a functional prosthesis. This case report describes the consequences of placing implants with no preoperative planning with regard to the implant position based on the final restorative plan. A 46-year-old male had all of his remaining maxillary and mandibular teeth extracted, and had 5 implants placed immediately in the interforaminal region of the mandible with the intent of providing a fixed prosthesis. Six weeks later, the patient was referred for prosthodontic care. The patient had no prostheses at that time and was in severe pain due to impingement of the lower lip by one of the implants. The implants were deemed to be in unfavorable positions and angulations. Thereafter, the case was treatment-planned systematically, requiring 2 additional surgical procedures---removal of one of the implants and alveoloplasty of posterior mandible for creation of space for prosthetic components. The remaining 4 implants with unfavorable angulations posed a prosthodontic challenge for fabrication of a prosthesis. The situation was eventually managed by fabrication of a screw-retained metal-resin fixed prosthesis over the remaining 4 implants. Although the situation was managed successfully, it resulted in increased time and treatment expenses, additional appointments, and elaborative steps for correction. Prosthodontics-driven treatment planning concepts and guidelines for prevention of such situations are described in this article. Published by Elsevier Inc.

  14. Corrections for inhomogeneities in biological tissue caused by blood vessels

    NARCIS (Netherlands)

    Talsma, A; Chance, B; Graaff, R

    In tissue optics, the assumption that blood is homogeneously distributed in tissue can give rise to miscalculations because blood is found only in blood vessels. In our paper randomly oriented blood vessels are treated as particles for which we obtained apparent absorption and scattering

  15. Survey on the Contemporary Management of Intraoperative Urethral Injuries During Penile Prosthesis Implantation.

    Science.gov (United States)

    Sexton, Stephanie J; Granieri, Michael A; Lentz, Aaron C

    2018-04-01

    Intraoperative urethral injury is an uncommon event during the placement of a penile prosthesis, and alternative management strategies have been proposed with continuation of implantation after urethral injury. To evaluate surgeon practices in the management of intraoperative urethral injury. An online survey was sent to the society listservs of the Genitourinary Reconstructive Surgeons (GURS) and the Sexual Medicine Society of North America (SMSNA). Physicians were queried on their fellowship training, experience with penile prosthesis implantation, and management of urethral injuries during prosthesis placement. The response data were analyzed using SAS 9.4 (SAS Institute, Cary, NC, USA). The χ 2 test and Fisher exact test were used to determine associations between variables. Survey responses. 131 survey responses were analyzed. Of the responders, 41.2% were GURS fellowship trained, 19.1% were SMSNA trained, 30.5% were non-fellowship trained, and 9.2% were trained in other fellowships. 25.4% of participants performed more than 50 implantations per year, 37.7% performed 20 to 50 per year, and 36.9% performed fewer than 20 per year. Urethral injury during prosthesis implantation was uncommon, with 26.2% reporting 0 injury, 58.5% reporting 1 to 3 injuries, and 15.4% reporting more than 3 career injuries. Injuries were most commonly encountered during corporal dilation (71.1%) compared with corporal exposure (12.5%) or penile straightening maneuvers (7.0%). There was no statistically significant difference with aborting or continuing implantation among GURS-trained, SMSNA-trained, other fellowship-trained, and non-fellowship-trained surgeons. Of all responders, 55% would abort the procedure after distal urethral injury, whereas 45% would continue the procedure with unilateral or bilateral insertion of cylinders. Patient factors that increased likelihood of terminating the procedure in the case of urethral injury included immunosuppression, spinal cord injury, and

  16. Association of the modified frailty index with adverse outcomes after penile prosthesis implantation.

    Science.gov (United States)

    Madbouly, Khaled; AlHajeri, Dulaim; Habous, Mohamad; Binsaleh, Saleh

    2017-06-01

    To investigate frailty as a predictor of surgical outcome in elderly patients undergoing penile prosthesis implantation. A total of 54 elderly patients, above 60 years of age, underwent penile prosthesis implantation between 2012 and 2014. Their data were collected and retrospectively analyzed. A modified frailty index (mFI) was calculated for each patient based on 11 risk factors from the Canadian Study of Health and Aging Frailty Index. The 1-year adverse outcomes were correlated with mFI, patients' and procedure's risk factors. Mean age was 64.9 ± 5.2 years. No mortality was reported in our patients, however, one-year adverse outcomes were encountered in 43 (79.6%) patients. Among all studied variables, the 1-year adverse outcomes was not significantly association with mFI, but with preoperative glycosylated hemoglobin A1c (HbA1c) (p = 0.031) and associated Peyronie's disease (PD) (p = 0.000). HbA1c, dyslipidemia, hypertension, PD and duration of the procedure were predictive of infection complications (p prosthesis implantation adverse outcomes in elderly patients with impotence. Degree of diabetic control and association with PD was associated with the 1-year adverse outcomes and infection complications.

  17. 3D Metal Printing - Additive Manufacturing Technologies for Frameworks of Implant-Borne Fixed Dental Prosthesis.

    Science.gov (United States)

    Revilla León, M; Klemm, I M; García-Arranz, J; Özcan, M

    2017-09-01

    An edentulous patient was rehabilitated with maxillary metal-ceramic and mandibular metal-resin implant-supported fixed dental prosthesis (FDP). Metal frameworks of the FDPs were fabricated using 3D additive manufacturing technologies utilizing selective laser melting (SLM) and electron beam melting (EBM) processes. Both SLM and EBM technologies were employed in combination with computer numerical control (CNC) post-machining at the implant interface. This report highlights the technical and clinical protocol for fabrication of FDPs using SLM and EBM additive technologies. Copyright© 2017 Dennis Barber Ltd.

  18. Management of aggressive periodontitis patient with implant supported prosthesis

    Directory of Open Access Journals (Sweden)

    Garima Jain

    2015-01-01

    Full Text Available Aggressive periodontitis (AgP comprises a group of rare, often severe, rapidly progressive forms of periodontitis which is characterized by an early age of clinical manifestations. It usually affects people under 30 years of age, but patients may be older. Microbiota associated are Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. The presence of highly pathogenic bacteria, severe periodontal bone destruction and the refractory nature of this disease tends to deter the clinician from placing implants in these patients. This case report demonstrates the placement of implants in a patient with AgP with successful 18 months follow-up.

  19. Free Gingival Graft to Increase Keratinized Mucosa after Placing of Mandibular Fixed Implant-Supported Prosthesis

    Directory of Open Access Journals (Sweden)

    Danny Omar Mendoza Marin

    2017-01-01

    Full Text Available Insufficiently keratinized tissue can be increased surgically by free gingival grafting. The presence or reconstruction of keratinized mucosa around the implant can facilitate restorative procedure and allow the maintenance of an oral hygiene routine without irritation or discomfort to the patient. The aim of this clinical case report is to describe an oral rehabilitation procedure of an edentulous patient with absence of keratinized mucosa in the interforaminal area, using a free gingival graft associated with a mandibular fixed implant-supported prosthesis. The treatment included the manufacturing of a maxillary complete denture and a mandibular fixed implant-supported prosthesis followed by a free gingival graft to increase the width of the mandibular keratinized mucosa. Free gingival graft was obtained from the palate and grafted on the buccal side of interforaminal area. The follow-up of 02 and 12 months after mucogingival surgery showed that the free gingival graft promoted peri-implant health, hygiene, and patient comfort. Clinical Significance. The free gingival graft is an effective treatment in increasing the width of mandibular keratinized mucosa on the buccal side of the interforaminal area and provided an improvement in maintaining the health of peri-implant tissues which allows for better oral hygiene.

  20. Bone density around the fixture after function of implant molar prosthesis using CBCT

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jae Hyun; Hwang, In Taik; Jung, Byung Hyun; Kim, Jae Duk; Kang, Dong Wan [School of Dentistry, Oral Biology Research Institute, Chosun University, Gwangju (Korea, Republic of)

    2010-03-15

    The purpose of this study was to examine the significance of increased bone density according to whether bone grafts were applied using demographic data with Cone Beam Computed Tomography (CBCT) and to compare the bone densities between before and after implant prosthesis using the Hounsfield index. Thirty-six randomly selected computed tomography (CT) scans were used for the analysis. The same sites were evaluated digitally using the Hounsfield scale with V-Implant 2.0TM, and the results were compared with maxillary posterior bone graft. Statistical data analysis was carried out to determine the correlation between the recorded Hounsfield unit (HU) of the bone graft and implant prosthesis using a Mann-Whitney U test and Wilcoxon Matched-pairs test. The bone grafted maxillary posterior teeth showed an increase in the mean values from-157 HU to 387 HU, whereas non-grafted maxillary posterior teeth showed an increase from 62 HU to 342 HU. After implantation, the grafted and non-grafted groups showed significantly higher bone density than before implantation. However, the grafted group showed significantly more changes than the non-grafted group. Bone density measurements using CBCT might provide an objective assessment of the bone quality as well as the correlation between bone density (Hounsfield scale) and bone grafts in the maxillary molar area.

  1. Screw retained vs. cement retained implant-supported fixed dental prosthesis.

    Science.gov (United States)

    Wittneben, Julia-Gabriela; Joda, Tim; Weber, Hans-Peter; Brägger, Urs

    2017-02-01

    A fixed dental prosthesis can be secured to an endosseous implant via cementation (using a provisional or definitive cement) on an implant abutment that is screw retained to the implant or directly in the implant via screw retention. The clinical decision as to which retention system best suits the individual patient depends on several factors. The aim of this review is to present a detailed overview of the factors potentially influencing whether to choose screw retention or cement retention. These factors include the individual indication, advantages and disadvantages of the different retention mechanisms, the retention provided, retrievability, provisionalization, esthetics and clinical performance, including failures and complications. The results of recently published systematic reviews on this topic are discussed and an overview is provided. A decision tree is presented to facilitate the clinical selection of the retention type. This overview concludes that the choice of retention type (screw retained or cement retained) might not influence the overall survival of the implant-supported fixed dental prosthesis, but may be responsible for the development of certain complications. The decision may depend on technical feasibility and on weighing the pros and cons. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Pseudo-capsule “coffin effect”: How to prevent penile retraction after implant of three-piece inflatable prosthesis

    Directory of Open Access Journals (Sweden)

    Enrico Caraceni

    2014-06-01

    Full Text Available Objective: Following three-component implantation of a penile prosthesis, some patients are dissatisfied with their penile length. This may be due to the procedure by itself or pre-existing risk factors or psychological reasons. We supposed that formation of a restricted pseudo-capsule due to a late prosthesis activation can inhibit later system expansion. We aimed to identify the presence or absence of penile retraction after implant and to prevent it by immediate prosthesis activation after implantation. Material and methods. Forty-six patients operated with three-piece inflatable penile prosthesis (AMS 700 CX o LGX were enrolled. In 27 patients prosthesis was first activated four weeks after surgery (NEA group and in 19 patients prosthesis was activated immediately after surgery (DEA group. Length and girth of the penis was evaluated before (in DEA group and after the surgical procedure. Results. The average post implant dorsal length of the erect penis in group NEA was found 3.28 cm shorter than in group with early activation (DEA. In DEA group there was no lenght difference between pre-operative stretching (14.57 cm and post operative erection (14.98 cm. When early activation was not performed, the clinical result was a smaller penis in erect phase. Conclusion. Reduced lenght of the penis after implantation can be caused by the presence of a pseudo-capsule that limits the elongation of the prosthesis and of the penis (“coffin effect”. Timing of first activation seems to be the key in order to prevent the risk of penile retraction after implantation. Early activation is identified as the best measure to maintain the length of the pre implant erect penis after the prosthetic hydraulic implant.

  3. Orthopaedic Implants And Prosthesis: Economic Costs Of Post ...

    African Journals Online (AJOL)

    OBJECTIVE: To assess the economic impact of post-operative wound infection in trauma patients who had open reduction and internal fixation with implants and prostheses following fractures of the femur. METHOD: This is a 2-year case controlled prospective study carried out at the National Orthopaedic Hospital, Lagos.

  4. Transcatheter aortic valve prosthesis surgically replaced 4 months after implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Lund, Jens Teglgaard; Engstrøm, Thomas

    2010-01-01

    Transcatheter aortic valve implantation is a new and rapidly evolving treatment option for high-risk surgical patients with degenerative aortic valve stenosis. Long-term results with these new valve prostheses are lacking, and potential valve dysfunction and failure would require valve replacemen...

  5. Clinical follow-up of unilateral, fixed dental prosthesis on maxillary implants.

    Science.gov (United States)

    Wahlström, Monica; Sagulin, Gun-Britt; Jansson, Leif E

    2010-11-01

    The aims of the present study were to evaluate (1) the success rate of unilateral maxillary fixed dental prosthesis (FDPs) on implants in patients at a periodontal clinic referred for periodontal treatment, (2) the prevalence of varying mechanical and biological complications and (3) effects of potential risk factors on the success rate. Fifty consecutive patients were invited to participate in a follow-up. The patients had received FDPs on implants between November 2000 and December 2003 after treatment to achieve optimal peridontal health, and the FDPs had been in function for at least 3 years. A questionnaire was sent to the patients before the follow-up examination. Forty-six patients with 116 implants were examined. The follow-up comprised clinical and radiographic examinations and evaluations of treatment outcome. Before implant treatment, 13% of the teeth were extracted; of these, 80% were extracted due to periodontal disease. No implants had been lost before implant loading. One implant in one patient fractured after 3 years of functional loading and three implants in another patient after 6.5 years. The most frequent mechanical complications were veneer fractures and loose bridge screws. Patients with peri-implant mucositis had significantly more bleeding on probing around teeth and implants. Patients with peri-implantitis at the follow-up had more deep periodontal pockets around their remaining teeth compared with individuals without peri-implantitis, but these differences were not significant. Smokers had significantly fewer teeth, more periodontal pockets ≥ 4mm and a tendency towards greater marginal bone loss at the follow-up, compared with non-smokers. In the short term, overloading and bruxism seem more hazardous for implant treatment, compared with a history of periodontitis.

  6. Penile prosthesis implantation in Chinese patients with severe erectile dysfunction: 10-year experience.

    Science.gov (United States)

    Song, Wei-Dong; Yuan, Yi-Ming; Cui, Wan-Shou; Wu, Alex K; Zhu, Yi-Chen; Liu, Jing; Wang, Lin; Bai, Guang-Yi; Peng, Jing; Zhang, Zhi-Chao; Gao, Bing; Guo, Ying-Lu; Lue, Tom F; Xin, Zhong-Cheng

    2013-09-01

    We retrospectively evaluated the clinical outcome of penile prosthesis implantation (PPI) in Chinese patients with severe erectile dysfunction (SED). From July 2000 to December 2011, 224 patients (mean age: 35.9±11.8 years, range: 20-75 years) with SED underwent PPI by experienced surgeon according to standard PPI procedure at our centre. A malleable prosthesis (AMS 650) was implanted in 45 cases (20.1%), and a three-piece inflatable prosthesis (AMS 700 CXM or AMS 700 CXR) was implanted in 179 cases (79.9%). Surgical outcomes, including postoperative complications, clinical efficacy and couple satisfaction, were evaluated over than 6 months postoperatively using medical record abstraction, IIEF-5, quality of life (QoL) scores, and the patient/partner sexual satisfaction score proposed by Bhojwani et al. Of the 224 patients eligible for the study, 201 subjects (89.7%) completed follow-up. All of patients could perform sexual intercourse post PPI with the mean postoperative IIEF-5 and QoL scores were 20.02±2.32 and 5.28±0.76, respectively, which were significantly improved compared with the preoperative scores (6.29±1.5 and 2.13±0.84, Pprosthesis group was higher than in the malleable prosthesis group (P<0.05). Satisfaction, however, between the types of prostheses, did not differ in the partner survey. PPI is a safe and effective treatment option for Chinese patients with SED and experienced surgeon perform PPI according to standard PPI procedure could reduce the postoperative complications of PPI and could improve patient satisfaction ratio and QoL.

  7. 10-year follow-up after implantation of the Bryan Cervical Disc Prosthesis.

    Science.gov (United States)

    Dejaegher, Joost; Walraevens, Joris; van Loon, Johannes; Van Calenbergh, Frank; Demaerel, Philippe; Goffin, Jan

    2017-04-01

    Cervical arthroplasty is being used as an alternative for cervical fusion, but long-term follow-up results have rarely been reported. In this paper, we present 10-year follow-up results after implantation of the Bryan Cervical Disc Prosthesis in a single center. 89 patients underwent implantation of a single-level Bryan Cervical Disc Prosthesis to treat radiculopathy and/or myelopathy. Clinical (Neurological Success, Neck Disability Index (NDI), Neck- and Arm-Pain, and SF-36) and radiological follow-up was prospectively organized up to 10 years after surgery. Adverse events and second surgeries were recorded and evaluated. Ten-year follow-up data were available for 72 (81%) patients. Maintenance or improvement of the neurological state was seen in 89% of patients after 10-year follow-up. SF-36 PCS scores improved significantly at all follow-up points. SF-36 MCS improvement was significant at 4 and 6 year, but not at 8- and 10-year follow-up. Significant improvement for NDI, and Neck- and Arm-Pain scores was found for the subgroup of patients in whom these data were available. Mean angular motion of the prosthesis at 10-year follow-up was 8.6°. Mobility of the device, defined as >2° of angular motion, was reached in 81% of patients. During the study period, 21 patients (24%) developed new or recurrent radiculopathy or myelopathy, the majority of these being treated conservatively. Seven patients (8%) required 8 additional spine surgeries to treat persistent or recurrent symptoms. Of these, 2 patients (2%) were reoperated at the index level and at 5 (6%) an adjacent level. In this study, favorable long-term clinical outcome after implantation of the Bryan Cervical Disc Prosthesis was seen, with the majority of prostheses remaining mobile after 10-year follow-up. However, still 6% of patients required adjacent level surgery.

  8. Effects of implant diameter and prosthesis retention system on the reliability of single crowns.

    Science.gov (United States)

    Bonfante, Estevam A; Almeida, Erika O; Lorenzoni, Fabio C; Coelho, Paulo G

    2015-01-01

    The probability of survival of implant-supported prostheses may be affected by the interplay between different implant diameters supporting screwed or cemented crowns. The purpose of this study was to investigate the effect of implant diameter and prosthesis retention system on the reliability and failure modes of single crowns. Internal-hexagon implants were divided into six groups (n = 21 each) according to implant diameter (3.3, 4.0, or 5.0 mm) and crown retention system (screwed or cemented). Abutments were torqued to the implants, and crowns were then fixed and subjected to step-stress accelerated life testing in water. Use-level probability Weibull curves and reliability for missions of 50,000 cycles at 100, 150, and 200 N were calculated. Failure analysis was performed. Cemented systems presented higher reliability than screwed ones, except between 3.3-mm-diameter cemented and screwed systems at a load of 100 or 150 N. Failure modes were restricted to the abutment screw and varied with implant diameter only in the cement-retained groups. Higher reliability was observed for cement-retained crowns and implants of larger diameter compared to screw-retained and smaller diameter. Failure modes differed between groups.

  9. Multidisciplinary approach of ectodermal dysplasia with implant retained fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Vishnu Priya

    2013-01-01

    Full Text Available Ectodermal dysplasia represents a group of rare inherited conditions in which two or more ectodermally derived anatomical structures fail to develop. Early dental intervention can improve patient′s appearance, thereby minimizing associated emotional and psychological problems in these patients. Treatment requires a teamwork by medical personnel along with dental professionals of various specialties. Here, a rare case of a young female patient is presented with prosthetic management with implant supported fixed partial denture.

  10. Penile prosthesis implantation for the treatment for male erectile dysfunction: clinical outcomes and lessons learnt after 955 procedures.

    Science.gov (United States)

    Chung, E; Van, C T; Wilson, I; Cartmill, R A

    2013-06-01

    To evaluate the clinical outcomes of penile prosthesis implantation for the treatment for erectile dysfunction (ED) over 3 decades in a centre of excellence. A total of 955 penile prostheses were implanted between June 1981 and June 2010. The mean age of the men was 53.2 (28-80) years, and the mean follow-up was 76 (12-355) months. A total of 771 men had primary implants. The most common implant was Ultrex cylinder (54 %), and the main cause of ED was organic (32 %). Primary implants showed higher rate of intra-operative complications than revision surgery (3.5 vs. 0.1 %) (p Prosthesis infection occurred in 0.8 % and equal incidence between diabetic and pelvic trauma patients. The average time to prosthetic revision was 102 (30-210) months. Kaplan-Meier estimates of overall penile prosthesis survival at 5 and 10 years were around 90.8 and 85.0 %. The most common mechanical failures were fluid loss (75 %). The majority of men were satisfied with the surgical outcomes, and 90 % of men would undergo penile prosthesis implant again. Penile prosthesis surgery is a safe and durable treatment option for male ED. Strict adherence to antimicrobial prophylaxis and surgical practice is paramount to ensure low complication rates and high patient satisfaction rate.

  11. Tissue Engineering of Blood Vessels: Functional Requirements, Progress, and Future Challenges.

    Science.gov (United States)

    Kumar, Vivek A; Brewster, Luke P; Caves, Jeffrey M; Chaikof, Elliot L

    2011-09-01

    Vascular disease results in the decreased utility and decreased availability of autologus vascular tissue for small diameter (engineered replacement vessels represent an ideal solution to this clinical problem. Ongoing progress requires combined approaches from biomaterials science, cell biology, and translational medicine to develop feasible solutions with the requisite mechanical support, a non-fouling surface for blood flow, and tissue regeneration. Over the past two decades interest in blood vessel tissue engineering has soared on a global scale, resulting in the first clinical implants of multiple technologies, steady progress with several other systems, and critical lessons-learned. This review will highlight the current inadequacies of autologus and synthetic grafts, the engineering requirements for implantation of tissue-engineered grafts, and the current status of tissue-engineered blood vessel research.

  12. Impact of patient-prosthesis mismatch after transcatheter aortic valve-in-valve implantation in degenerated bioprostheses

    DEFF Research Database (Denmark)

    Seiffert, Moritz; Conradi, Lenard; Baldus, Stephan

    2012-01-01

    Transcatheter valve-in-valve implantation is evolving as an alternative to reoperative valve replacement in high-risk patients with degenerated bioprostheses. Nevertheless, hemodynamic performance is limited by the previously implanted xenograft. We report our experience with patient-prosthesis...

  13. Using the "final-on-four" concept to deliver an immediate metal-resin implant-fixed complete dental prosthesis.

    Science.gov (United States)

    Yilmaz, Burak; Ozcelik, Tuncer Burak; McGlumphy, Edwin

    2015-08-01

    In traditional dental implant therapy, the time between implant placement and delivery of the definitive prosthesis can be long and uncomfortable for a patient wearing a conventional removable denture on an atrophied ridge. New clinical protocols, often with tilted implants, are being used to immediately restore mandibular implants with interim restorations, thus shortening the patient's return to function. However, these conversion type interim restorations do not decrease the time to definitive prosthetic rehabilitation. The Ohio State University (OSU) developed an immediate load surgical and prosthetic protocol to compensate for the disadvantages of previous techniques. With this protocol, a custom, definitive, screw-retained metal-resin fixed prosthesis can be delivered 2 to 4 days postoperatively and has been described using 5 implants. This clinical report presents the OSU immediate loading protocol, combined with a tilted implant technique, for the fabrication of a mandibular metal-resin implant fixed complete dental prosthesis (MRIFCDP) in 3 days postoperatively and with only 4 implants. Replacing the mandibular dentition with an immediate load-fixed metal-resin prosthesis by means of the "final-on-four" technique resulted in a custom, definitive, and functional restorative solution immediately after surgery. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. Influence of prosthesis type and material on the stress distribution in bone around implants: A 3-dimensional finite element analysis

    Directory of Open Access Journals (Sweden)

    Gökçe Meriç

    2011-03-01

    Conclusions: Prosthesis design and materials affect the load-transmission mechanism. Although additional experimental and clinical studies are needed, FRC FPDs can be considered a suitable alternative treatment choice for implant-supported prostheses. Within the limitations of the study, the 3-unit FPD supported by 2 implants with a cantilevered extension revealed acceptable stress distributions.

  15. Bilateral implant-retained auricular prosthesis for a patient with congenitally missing ears. A clinical report.

    Science.gov (United States)

    Kumar, Preeti Satheesh; Satheesh Kumar, K S; Savadi, Ravindra C

    2012-06-01

    Microtia is a major congenital anomaly of the external ear. It includes a spectrum of deformities from a grossly normal but small ear to the absence of the entire external ear. These deformities account for three in every 10,000 births, with bilaterally missing ears seen in fewer than 10% of all cases. Congenital abnormalities of the ear are unlikely to result in the complete absence of the ears, but the patient presented in this article had bilateral congenitally missing ears. There was loss of anatomic landmarks and alteration of normal bony architecture. Minimal tissue was available for retention; therefore, conventional techniques could not be used for achieving retention. A two-implant-supported auricular prosthesis was planned, but the patient was found to have deficient bone in the implant site. Hence the implants were placed posterior to these sites, and the superstructure was modified to accommodate for this change in position of the implant to ensure the esthetic positioning of the prosthesis. © 2012 by the American College of Prosthodontists.

  16. Stent valve implantation in conventional redo aortic valve surgery to prevent patient-prosthesis mismatch.

    Science.gov (United States)

    Ferrari, Enrico; Franciosi, Giorgio; Clivio, Sara; Faletra, Francesco; Moccetti, Marco; Moccetti, Tiziano; Pedrazzini, Giovanni; Demertzis, Stefanos

    2017-03-01

    The goal was to show the technical details, feasibility and clinical results of balloon-expandable stent valve implantation in the aortic position during conventional redo open-heart surgery in selected obese patients with a small aortic prosthesis and severe patient-prosthesis mismatch. Two symptomatic overweight patients (body mass index of 31 and 38), each with a small aortic prosthesis (a 4-year-old, 21-mm Hancock II biological valve and a 29-year-old, 23-mm Duromedic mechanical valve), increased transvalvular gradients (59/31 and 74/44 mmHg) and a reduced indexed effective orifice area (0.50 and 0.43 cm 2 /m 2 ) underwent implantation of two 26-mm balloon-expandable Sapien 3 valves during standard on-pump redo valve surgery. Using full re-sternotomy, cardiopulmonary bypass and cardioplegic arrest, the two balloon-expandable stent valves were implanted under direct view using a standard aortotomy, after prosthesis removal and without annulus enlargement. Aortic cross-clamp times were 162 and 126 min; cardiopulmonary bypass times were 178 and 180 min; total surgical times were 360 and 318 min. At discharge, echocardiograms showed transvalvular peak and mean gradients of 13/9 and 23/13 mmHg and indexed effective orifice areas of 0.64 and 1.08 cm 2 /m 2 . The 3-month echocardiographic follow-up showed transvalvular peak and mean gradients of 18/9 and 19/11 mmHg and indexed effective orifice areas of 0.78 cm 2 /m 2 and 0.84 cm 2 /m 2 , with improved symptoms (New York Heart Association class 1). Implantation of a balloon-expandable stent valve during redo aortic valve surgery is feasible in selected cases and prevents patient-prosthesis mismatch in obese patients without need for aortic annulus enlargement. Moreover, in the case of stent valve degeneration, this approach permits additional valve-in-valve procedures with large stent valves and prevents re-redo surgery. © The Author 2016. Published by Oxford University Press on behalf of the

  17. Fabrication of a Customized Ball Abutment to Correct a Nonparallel Implant Abutment for a Mandibular Implant-Supported Removable Partial Prosthesis: A Case Report

    Directory of Open Access Journals (Sweden)

    Hossein Dasht

    2017-12-01

    Full Text Available Introduction: While using an implant-supported removable partial prosthesis, the implant abutments should be parallel to one another along the path of insertion. If the implants and their attachments are placed vertically on a similar occlusal plane, not only is the retention improved, the prosthesis will also be maintained for a longer period. Case Report: A 65-year-old male patient referred to the School of Dentistry in Mashhad, Iran with complaints of discomfort with the removable partial dentures for his lower mandible. Due to the lack of parallelism in the supporting implants, prefabricated ball abutment could not be used. As a result, a customized ball abutment was fabricated in order to correct the non-parallelism of the implants. Conclusion: Using UCLA abutments could be a cost-efficient approach for the correction of misaligned implant abutments in implant-supported overdentures.

  18. The KineSpring® Knee Implant System: an implantable joint-unloading prosthesis for treatment of medial knee osteoarthritis

    Directory of Open Access Journals (Sweden)

    Clifford AG

    2013-05-01

    Full Text Available Anton G Clifford,1 Stefan M Gabriel,1 Mary O’Connell,1 David Lowe,1 Larry E Miller,2,3 Jon E Block31Moximed, Inc, Hayward, CA, USA; 2Miller Scientific Consulting, Inc, Arden, NC, USA; 3The Jon Block Group, San Francisco, CA, USAAbstract: Symptomatic medial compartment knee osteoarthritis (OA is the leading cause of musculoskeletal pain and disability in adults. Therapies intended to unload the medial knee compartment have yielded unsatisfactory results due to low patient compliance with conservative treatments and high complication rates with surgical options. There is no widely available joint-unloading treatment for medial knee OA that offers clinically important symptom alleviation, low complication risk, and high patient acceptance. The KineSpring® Knee Implant System (Moximed, Inc, Hayward, CA, USA is a first-of-its-kind, implantable, extra-articular, extra-capsular prosthesis intended to alleviate knee OA-related symptoms by reducing medial knee compartment loading while overcoming the limitations of traditional joint-unloading therapies. Preclinical and clinical studies have demonstrated excellent prosthesis durability, substantial reductions in medial compartment and total joint loads, and clinically important improvements in OA-related pain and function. The purpose of this report is to describe the KineSpring System, including implant characteristics, principles of operation, indications for use, patient selection criteria, surgical technique, postoperative care, preclinical testing, and clinical experience. The KineSpring System has potential to bridge the gap between ineffective conservative treatments and irreversible surgical interventions for medial compartment knee OA.Keywords: KineSpring, knee, medial, osteoarthritis, prosthesis

  19. Implant retained auricular prosthesis with a modified hader bar: a case report.

    Science.gov (United States)

    Lovely, M; Dathan, Pradeep C; Gopal, Dinesh; George, Biji Thomas; Chandrasekharan Nair, K

    2014-06-01

    Auricular prostheses for defects of external ear are retained either by mechanical means or implants. All implant retained prostheses are retained by various means such as bar and clip, magnetic attachments or a combination of bar, clip and magnets. The commonest problem encountered with the bar and clip system is loosening of the clip after 3-4 months. When magnets are used as retaining component they tend to corrode over a period of time. So various alternative retention methods which possess good retentive qualities, ease of reparability and patient friendly were tried. In the present case a newly modified Hader bar design which can act as an additional retentive feature apart from the clip is employed to increase retention. The major advantages in the modified Hader bar system were that only two implants were employed, the additional loops in the Hader bar prevented micro movements and the retentive acrylic locks were easy to repair if broken. The modified Hader bar has anti-rotational slots which prevents the sliding or rotation of the prosthesis which gave new confidence to the patient who was otherwise worried of inadvertent displacement of the ear prosthesis while playing.

  20. Polygonal Area of Prosthesis Support with Straight and Tilted Dental Implants in Edentulous Maxillae.

    Science.gov (United States)

    Wentaschek, Stefan; Lehmann, Karl Martin; Scheller, Herbert; Weibrich, Gernot; Behneke, Nikolaus

    2016-01-01

    The aim of this in vitro study was to assess the increase in the polygonal area of implant-retained prosthesis supports in edentulous maxillae with the use of tilted distal implants compared with the use of straight distal implants, using a variety of implant lengths. A total of 25 DICOM datasets of atrophic edentulous maxillae were provided. Bone augmentations in the molar region had to be avoided. Two straight reference implants were virtually inserted in the anterior region. Two additional implants were placed far distally on both sides (4 groups: [1] straight, 12-mm length; [2] straight, 10 mm; [3] straight, 8 mm; [4] tilted, 12-16 mm). The resulting implant-supported polygon was measured for each of the 4 groups using three-dimensional planning software. The mean sagittal depth of the supported polygon in Group 1 was 9.9 mm (standard deviation [SD] 4.4) on the right and 10.2 mm (SD 4.4) on the left, and it was 33.7 mm (SD 5.8) in width. For Group 2, the mean sagittal depth was 11.5 mm (SD 5.0) on the right and 11.9 mm (SD 4.7) on the left, and the width was 35.2 mm (SD 5.6). The measurements for Group 3 were 13.8 mm (SD 4.9) deep on the right, 13.8 mm (SD 5.1) deep on the left, and 37.0 mm (SD 5.4) in width. For Group 4, the depth was 15.8 mm (SD 4.9) on the right and 16.4 mm (SD 5.8) on the left, and the width was 39.0 mm (SD 5.1). The area of implant-retained prosthesis support can be enlarged by the use of tilted implants (12 to 16 mm in length, 42 to 45 degrees) compared to the use of straight 8-mm implants (resulting increase: about 15%).

  1. Long-term outcomes of AMS Spectra® penile prosthesis implantation and satisfaction rates.

    Science.gov (United States)

    Akdemir, F; Okulu, E; Kayıgil, Ö

    2017-09-01

    The aim of this study was to evaluate the surgical implantation techniques of AMS Spectra malleable penile prosthesis, its intraoperative and postoperative complications, and the rates of patient and partner satisfaction. Forty-six patients on whom AMS Spectra malleable penile prosthesis implantation was performed between 2009 and 2014 were retrospectively examined. Any complications seen intraoperatively and postoperatively were determined. International Index of Erectile Function (IIEF)-5, total IIEF erectile function domain scores were calculated preoperatively. IIEF-5, total IIEF erectile function domain and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) scores were calculated in the postoperative third, sixth and twelfth months. The mean age of the patients was 63.6±7.28 (38-80) years. The mean erectile dysfunction period was 4.29±2.51 years, and the mean follow-up period was 3.19±1.6 years. The mean IIEF-5 score was 5.86±0.92 before surgery, and it was 22.5±0.62 at the end of the follow-up. The mean total IIEF erectile function domain score was 6.02±1.09 before surgery, and it was 26.02±0.21 at the end of the follow-up. The mean EDITS score was 71.06±3.16 at the end of the follow-up. The mean EDITS score of the patients partners was 65.08±4.34 at the end of the follow-up. The overall satisfaction rates were 96.2% for the patients and 84.6% for the partners. As a result of this study, the AMS Spectra penile prosthesis implantation is an effective, reliable and economic method. It can be used in the treatment of erectile dysfunction in selected patient groups offering high patient and partner satisfaction rates.

  2. Biomechanical evaluation of spring system for implant-supported prosthesis: analysis by photoelasticity and extensometry.

    Science.gov (United States)

    Goiato, Marcelo Coelho; de Medeiros, Rodrigo Antonio; da Silva, Emily Vivianne Freitas; Sônego, Mariana Vilela; Dos Santos, Daniela Micheline

    2017-05-01

    New systems are released in the odontological market with the objective of bringing improvements and advancements in the clinical success of implants and implant-supported prostheses. The distribution of tension for the bone/implant system of these new systems is important. The purpose of this work was to evaluate, by photoelastic analysis and strain gauges, the distribution of tension for the bone/implant system, using the Slim system. A photoelastic cast with an external hexagon implant was manufactured and a metal prosthesis was screwed below it, with or without the tested system. For the photoelasticity methodology, a photoelastic cast, with or without the tested system, was positioned in a circular polariscope, and axial loads of 100 N were applied to the centre of the crown. The pattern of tension generated was photographed and analysed qualitatively in an imaging programme. For the extensometry methodology, two extensometers were placed in the mesial and distal region of the implant in the photoelastic cast. The axial loads were applied to the group again, with or without the system (n = 10). The t test of independent samples with a significance level of 5% was used for this analysis. This study demonstrated greater tension values for both the photoelastic and extensometry methods when the tested system was used. Clinical studies must be performed to evaluate the tested system because the results might not be clinically significant to a bone reabsorption.

  3. Bone marrow blood vessels: normal and neoplastic niche

    Directory of Open Access Journals (Sweden)

    Saeid Shahrabi

    2016-11-01

    Full Text Available Blood vessels are among the most important factors in the transport of materials such as nutrients and oxygen. This study will review the role of blood vessels in normal bone marrow hematopoiesis as well as pathological conditions like leukemia and metastasis. Relevant literature was identified by a Pubmed search (1992-2016 of English-language papers using the terms bone marrow, leukemia, metastasis, and vessel. Given that blood vessels are conduits for the transfer of nutrients, they create a favorable situation for cancer cells and cause their growth and development. On the other hand, blood vessels protect leukemia cells against chemotherapy drugs. Finally, it may be concluded that the vessels are an important factor in the development of malignant diseases.

  4. A novel open-tray impression technique for fabrication of a provisional prosthesis on immediate load implants in a completely edentulous arch.

    Science.gov (United States)

    Kaneko, Takahiro; Yamagishi, Kiyoshi; Horie, Norio; Shimoyama, Tetsuo

    2013-01-01

    To evaluate the clinical outcome of a novel open-tray impression technique for fabrication of a provisional prosthesis supported by immediately loaded implants in a completely edentulous arch. An open-tray impression technique was evaluated in this retrospective study that included patients treated between March 2006 and October 2009. Preoperatively, a diagnostic prosthesis was delivered, and a novel open tray was fabricated based on this prosthesis. After implant placement, the impression and interocclusal record were taken simultaneously using the novel open tray. Laboratory-fabricated, screw-retained, all-acrylic resin provisional restorations were delivered on the same day of surgery. The prosthesis was assessed from the day of surgery until replacement with a definitive prosthesis. The study included 21 patients (mean age, 64.5 years) and a total of 125 implants. Of these, 104 implants were immediately loaded. In all patients, well-fitting provisional restorations supported by a minimum of four implants were delivered. Fracture of the first molar cusp was observed in one case after 30 days. However, there was no extensive fracture in the framework or functional disorder of the prosthesis. No implant failed during the follow-up after implant surgery. This protocol enabled fabrication of a well-fitting acrylic resin provisional prosthesis supported by immediately loaded implants because the impression was taken while in centric occlusion and an occlusion identical to the diagnostic prosthesis could be reconstructed.

  5. Fracture of the delivery balloon shaft during balloon-expandable prosthesis alignment during implantation of an Edwards SAPIEN 3.

    Science.gov (United States)

    Arai, Takahide; Hovasse, Thomas; Chevalier, Bernard

    2018-04-01

    The expandable sheath was designed with a lower profile in order to reduce the incidence of vascular complications of transcatheter aortic valve implantation using transfemoral approach. However, once the prosthesis has crossed the sheath, it could be difficult to retrieve it from the body. This is the first case of successful bail-out in an instance of delivery balloon shaft malfunction subsequent to the crossing of an expandable sheath during implantation of an Edwards SAPIEN 3 prosthesis. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. Complications and Clinical Considerations of the Implant-Retained Zirconia Complete-Arch Prosthesis with Various Opposing Dentitions.

    Science.gov (United States)

    Gonzalez, Jorge; Triplett, Robert G

    To evaluate the performance of the implant-retained zirconia complete-arch prosthesis with various opposing dentitions. The 40 patients included in this retrospective case series study were treated with one or two implant-retained zirconia complete-arch prostheses (ZIRCAP) using the Zirkonzahn protocol. Prettau zirconia frames were created with strategic cutbacks in the structure to extend zirconia incisal coverage of the esthetic anterior sextants and complete monolithic zirconia in the molar areas; subsequent layers of porcelain were applied to nonfunctional and esthetic areas. Patients had three possible occlusal scenarios: (1) maxillary ZIRCAP and mandibular ZIRCAP, (2) maxillary ZIRCAP and mandibular natural dentition, and (3) maxillary ZIRCAP and mandibular conventional hybrid prosthesis. Complications were recorded during follow-up appointments 3, 6, and 12 months after definitive prosthesis delivery. The mean treatment observation period was 33 months. Eight prosthetic complications were noted for the 40 implant-retained zirconia complete-arch prostheses (18.18%), including six cases of minor porcelain chipping and two cases of debonding of the metal insert from the zirconia framework. Maxillary ZIRCAP opposing mandibular ZIRCAP and maxillary ZIRCAP opposing mandibular natural dentition occlusal scenarios presented the same complication ratio of 4. No complications were seen in the maxillary ZIRCAP opposing mandibular conventional hybrid prosthesis group, yet 16 complications were found as denture tooth fractures in 12 mandibular conventional hybrid prostheses (ratio of 0.75). The results indicate that the implant-retained zirconia complete-arch prosthesis offers acceptable performance for use as an alternative to the conventional titanium framework acrylic veneer prosthesis for complete edentulism with a lower incidence of prosthetic complications and fewer maintenance appointments. Chipping of veneering porcelain was the most common complication, but a

  7. Percutaneous implantation of the first repositionable aortic valve prosthesis in a patient with severe aortic stenosis.

    Science.gov (United States)

    Buellesfeld, Lutz; Gerckens, Ulrich; Grube, Eberhard

    2008-04-01

    Percutaneous aortic valve replacement is a new less-invasive alternative for high-risk surgical candidates with aortic stenosis. However, the clinical experience is still limited, and the currently available 'first-generation devices' revealed technical shortcomings, such as lack of repositionability and presence of paravalvular leakages. We report the first-in-man experience with the new self-expanding Lotus Valve prosthesis composed of a nitinol frame with implemented bovine pericardial leaflets which is designed to address these issues, being repositionable and covered by a flexible membrane to seal paravalvular gaps. We implanted this prosthesis in a 93-year old patient presenting with severe symptomatic aortic stenosis (valve area: 0.6 cm(2)). Surgical valve replacement had been declined due to comorbidities. We used a retrograde approach for insertion of the 21-French Lotus catheter loaded with the valve prosthesis via surgical cut-down to the external iliac artery. Positioning of the valve was guided by transesophageal echo and supra-aortic angiograms. The prosthesis was successfully inserted and deployed within the calcified native valve. Echocardiography immediately after device deployment showed a significant reduction of the transaortic mean pressure gradient (32 to 9 mmHg; final valve area 1.7 cm(2)) without evidence of residual aortic regurgitation. The postprocedural clinical status improved from NYHA-IV to NYHA-II. These results remained unchanged up to the 3 month follow-up. Successful percutaneous aortic valve replacement can be performed using the new self-expanding and repositionable Lotus valve for treatment of high-risk patients with aortic valve stenosis. Further studies are mandatory to assess device safety and efficacy in larger patient populations. Copyright 2008 Wiley-Liss, Inc.

  8. Description of the condition of the implant-prosthesis system: a transverse study

    International Nuclear Information System (INIS)

    Salazar Salgado, Walter

    2008-01-01

    Current condition of the implant-prosthesis system of the patients attended in the Facultad de Odontologia de la Universidad de Costa Rica is described, in the included period from January 2001 to December 2006. Parameters of comparison will be established for future evaluations. An appointment was scheduled with each patient to review. A radiovisiograph was used for digital radiography with parallel technique and radiographic positioners, for anterior and posterior sector. In addition, a questionnaire was applied to all patients. The percentage of survival of the implants placed in the years 2001-2006, is 95.2 % and 92.4 % of the patients are satisfied with the aesthetic aspect of their restoration [es

  9. An Investigation of Three types of Tooth Implant Supported Fixed Prosthesis Designs with 3D Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Sara Koosha

    2013-01-01

    Full Text Available Objective: Tooth/implant supported fixed prostheses may present biomechanical design problems, as the implant is rigidly anchored within the alveolus, whereas the tooth is attached by the periodontal ligament to the bone allowing movement. Many clinicians prefer tooth/implant supported fixed prosthesis designs with rigid connectors. However, there are some doubts about the effect of attachment placement in different prosthesis designs. The purpose of this study was to examine the stresses accumulated around the implant and natural teeth under occlusal forces using three dimensional finite element analysis (3D FEA.Materials and Methods: In this study, different connection designs of tooth/implant fixed prosthesis in distal extension situations were investigated by 3D FEA. Three models with various connection designs were studied; in the first model an implant rigidly connected to an abutment, in the second and third models an implant connected to abutment tooth with nonrigid connector in the distal part of the tooth and mesial part of the implant. In each model, a screw type implant (5×11mm and a mandibular second premolar were used. The stress values of these models loaded with vertical forces (250N were analyzed.Results: There was no difference in stress distribution around the bone support of the implant. Maximum stress values were observed at the crestal bone of the implant. In all models, tooth movement was higher than implant movement.Conclusion: There is no difference in using a rigid connector, non rigid connector in the distal surface of the tooth or in the mesial surface of an implant.

  10. [The standard implantation of a total hip prosthesis via two incisions (the Yale Technique)].

    Science.gov (United States)

    Kipping, Robert

    2009-09-01

    Implantation of a total hip endoprosthesis with minimal trauma to the soft tissue. The need for visual aids (e.g., navigation or X-rays) during the procedure is frequently avoided. All kinds of coxarthrosis for every age group, for every variation of bone construction, and even in obese patients. Extremely dysplastic hip joints involving the development of a secondary socket and the necessity of reconstruction of the acetabular socket (e.g., in the Harris method). Using a fixed lateral position, a small entry incision is made between the tensor fasciae latae and the sartorius muscles and the prosthesis socket is put into place. Via a second dorsal incision, after stripping the exterior rotators, the prosthesis stem and ball are implanted and the two parts of the prosthesis are attached. Full weight bearing allowed immediately. A luxation prophylaxis, in the form of a self-developed hip bodice (the so-called Yale bandage), is used until the end of the 4th postoperative week. Discharge from hospital is possible after just a few days. Upon discharge, the patient is sent to a rehabilitation facility, either as a resident or as an outpatient, for approximately 3 weeks. Return to the workplace, with only light physical activity, is possible once the wound has healed completely; this could be as soon as 14 days after the operation. Checkups are made after 4 weeks, 6 months, 1 year and then every year; these checkups include a full examination, X-rays and laboratory tests. Full exposure to sport or heavy manual labor is usually approved after the 6-month checkup. Between October 2004 and April 2006, a total of 221 patients underwent surgery using this new technique (of these 15 patients underwent two-stage bilateral hip joint replacements). Patients were followed up for a minimum of 12 months and a maximum of 30 months. The Harris Hip Score improved from an average of 45.25 preoperatively to 96.4 postoperatively.

  11. The impact of diabetes mellitus on penile length in men undergoing inflatable penile prosthesis implantation.

    Science.gov (United States)

    Akın, Yiğit; Şahiner, İlker Fatih; Usta, Mustafa Faruk

    2013-09-01

    To evaluate the changing cavernosal length of patients with diabetes mellitus (DM) and organic erectile dysfunction (ED) who were treated with inflatable, three-piece penile prostheses, a current surgical treatment option in our clinic, over the course of 12 years. Between April 2000 and December 2012, we retrospectively investigated data from patients who were diagnosed with organic ED and undergone penile prosthesis implantation (PPI). Of the 239 patients, 235 of them were included in the study. Four patients who were operated on for trans-sexuality were excluded from the study. All patients were divided into two groups as those with (Group 1) or without DM (Group 2). Data, including age, body mass index (BMI) in kg/m(2), surgical history, comorbidities, International Index of Erectile Function (IIEF) questionnaire scores, combined intracavernous injection and stimulation (CIS) test results, length of corpus cavernosum while implanting the penile prosthesis, complications, operative times, mean hospital stay, and satisfaction of the patient and partner, were recorded. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis. A p-value of 0.05). The length of the corpus cavernosum and the destruction of cavernosal tissues do not depend only on DM. We conclude that these features may have multifactorial causes.

  12. Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR

    Directory of Open Access Journals (Sweden)

    Duda Georg N

    2011-05-01

    Full Text Available Abstract Background Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This study investigates the influences of femoral anteversion and offset on stresses in the Wagner SL revision stem implant under varying extents of bone defect conditions. Methods Wagner SL revision stems with standard (34 mm and increased offset (44 mm were virtually implanted in a model femur with bone defects of variable extent (Paprosky I to IIIb. Variations in surgical technique were simulated by implanting the stems each at 4° or 14° of anteversion. Muscle and joint contact forces were applied to the reconstruction and implant stresses were determined using finite element analyses. Results Whilst increasing the implant's offset by 10 mm led to increased implant stresses (16.7% in peak tensile stresses, altering anteversion played a lesser role (5%. Generally, larger stresses were observed with reduced bone support: implant stresses increased by as much as 59% for a type IIIb defect. With increased offset, the maximum tensile stress was 225 MPa. Conclusion Although increased stresses were observed within the stem with larger offset and increased anteversion, these findings indicate that restoration of offset, key to restoring joint function, is unlikely to result in excessive implant stresses under routine activities if appropriate fixation can be achieved.

  13. Prosthesis-guided implant restoration of an auricular defect using computed tomography and 3-dimensional photographic imaging technologies: a clinical report.

    Science.gov (United States)

    Wang, Shuming; Leng, Xu; Zheng, Yaqi; Zhang, Dapeng; Wu, Guofeng

    2015-02-01

    The concept of prosthesis-guided implantation has been widely accepted for intraoral implant placement, although clinicians do not fully appreciate its use for facial defect restoration. In this clinical report, multiple digital technologies were used to restore a facial defect with prosthesis-guided implantation. A simulation surgery was performed to remove the residual auricular tissue and to ensure the correct position of the mirrored contralateral ear model. The combined application of computed tomography and 3-dimensional photography preserved the position of the mirrored model and facilitated the definitive implant-retained auricular prosthesis. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W. Sr.

    1992-01-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system use relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, Monte Carlo calculations were performed using the code Electron Gamma Shower (EGS4). Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessel sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was or cross fire between blood vessels was assumed. Results are useful in assessing the doses to blood and blood vessel walls for different nuclear medicine procedures

  15.  Evaluation of the humoral and cellular immune responses after implantation of a PTFE vascular prosthesis.

    Science.gov (United States)

    Skóra, Jan; Pupka, Artur; Dorobisz, Andrzej; Barć, Piotr; Korta, Krzysztof; Dawiskiba, Tomasz

    2012-07-02

    The experiment was designed in order to determine the immunological processes that occur during the healing in synthetic vascular grafts, especially to establish the differences in the location of the complement system proteins between the proximal and distal anastomosis and the differences in the arrangement of inflammatory cells in those anastomoses. The understanding of those processes will provide a true basis for determining risk factors for complications after arterial repair procedures. The experiment was carried out on 16 dogs that underwent implantation of unilateral aorto-femoral bypass with expanded polytetrafluoroethylene (ePTFE). After 6 months all animals were euthanized to dissect the vascular grafts. Immunohistochemical assays and electron microscopic examinations were performed. Immunohistochemical findings in the structure of neointima between anastomoses of vascular prostheses demonstrated significant differences between humoral and cellular responses. The area of proximal anastomosis revealed the presence of fibroblasts, but no macrophages were detected. The histological structure of the proximal anastomosis indicates that inflammatory processes were ended during the prosthesis healing. The immunological response obtained in the distal anastomosis corresponded to the chronic inflammatory reaction with the presence of macrophages, myofibroblasts and deposits of complement C3. The identification of differences in the presence of macrophages and myofibroblasts and the presence of the C3 component between the anastomoses is the original achievement of the present study. In the available literature, no such significant differences have been shown so far in the humoral and cellular immune response caused by the presence of an artificial vessel in the arterial system.

  16. Cementable implant-supported prosthesis, serial extraction, and serial implant installation: case report.

    Science.gov (United States)

    Rosen, Harry; Gornitsky, Mervyn

    2004-12-01

    Cement-retained implant-supported prostheses are particularly indicated where access for screw placement is limited or impossible like in posterior locations or where there is limited jaw opening. The patient in this case report suffered from limited jaw opening as a result of a long history of temporomandibular joint ankylosis related to hemophilia. Cement-retained implant-supported prostheses coupled with serial extraction, serial implant installations, and chairside provisional restorations made uneventful treatment possible.

  17. The use of high-hydrostatic pressure treatment to decellularize blood vessels.

    Science.gov (United States)

    Funamoto, Seiichi; Nam, Kwangwoo; Kimura, Tsuyoshi; Murakoshi, Ayako; Hashimoto, Yoshihide; Niwaya, Kazuo; Kitamura, Soichiro; Fujisato, Toshiya; Kishida, Akio

    2010-05-01

    A decellularization method using high-hydrostatic pressure (HHP) technology (>600MPa) is described. The HHP disrupts the cells inside the tissue. The cell debris can be eliminated with a simple washing process, producing clean, decellularized tissue. In this study, porcine aortic blood vessel was decellularized by HHP. The mechanical properties and in vivo performance of the decellularized tissue were evaluated. Mechanical properties of the decellularized tissue were not altered by the HHP treatment. Reduced inflammation of the decellularized tissue was confirmed by xenogenic transplant experimentation. An allogenic transplantation study showed that decellularized blood vessel endured the arterial blood pressure, and there was no clot formation on the luminal surface. In addition, cellular infiltration into the vessel wall was observed 4 weeks after implantation, suggesting that HHP treatments could be applied widely as a high-quality decellularization method. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. Combined inflatable penile prosthesis-artificial urinary sphincter implantation: no increased risk of adverse events compared to single or staged device implantation.

    Science.gov (United States)

    Segal, Robert L; Cabrini, Mercelo R; Harris, Elaine D; Mostwin, Jacek L; Bivalacqua, Trinity J; Burnett, Arthur L

    2013-12-01

    Little data exist on the outcome of combined inflatable penile prosthesis and artificial urinary sphincter insertion for erectile dysfunction and stress urinary incontinence. We assessed patient outcomes for combined vs single device implantation at a single institution. We retrospectively reviewed the records of all patients who underwent inflatable penile prosthesis and artificial urinary sphincter insertion at our hospital from January 2000 to December 2011. A total of 55 combined procedures were performed compared to the single insertion of 336 inflatable penile prostheses and 279 artificial urinary sphincters. The surgical approach consisted of penoscrotal incisions for inflatable penile prostheses and transperineal incisions for artificial urinary sphincter cuff placement with a secondary lower abdominal incision for reservoir placement. Men treated with combined implantation had greater mean age and were at greater risk for prostate cancer diagnosis and treatment, and at lesser risk for Peyronie disease than men who received an inflatable penile prosthesis alone (each pprosthesis alone and the AUS alone (mean 218.1 vs 145.9 and 114.7 minutes, respectively, p0.05). Combined inflatable penile prosthesis-artificial urinary sphincter implantation and staged prosthesis implantation are feasible without an increased risk of adverse outcomes compared to implantation of a single prosthesis. Patients with concomitant erectile dysfunction and stress urinary incontinence should be counseled about the possible advantages of this surgical option, which include a single anesthesia event and faster resumption of sexual activity and urinary control. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  19. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W.

    1991-05-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system used relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, EGS4 Monte Carlo calculations were performed. Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessels sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was assumed nor cross fire between vessel was assumed. Results are useful in assessing the dose in blood and blood vessel walls for different nuclear medicine procedures. 6 refs., 6 figs., 5 tabs

  20. Instability and `Sausage-String' Appearance in Blood Vessels during High Blood Pressure

    OpenAIRE

    Alstrom, Preben; Eguiluz, Victor M.; Colding-Jorgensen, Morten; Gustafsson, Finn; Holstein-Rathlou, Niels-Henrik

    1998-01-01

    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.

  1. Vasodilator effect of nicorandil on retinal blood vessels in rats.

    Science.gov (United States)

    Ogawa, Naoto; Saito, Maki; Mori, Asami; Sakamoto, Kenji; Kametaka, Sokichi; Nakahara, Tsutomu; Ishii, Kunio

    2007-07-01

    We examined the effect of nicorandil on retinal blood vessels in rats in vivo. Male Wistar rats (8 to 10 weeks old) were anaesthetised with thiobutabarbital (120 mg/kg, intraperitoneal). Fundus images were captured with a digital camera that was equipped with a special objective lens. Diameters of retinal blood vessels were measured with a personal computer. Nicorandil (1-300 microg kg(-1) min(-1), intravenous [i.v.]) increased diameters of retinal blood vessels and decreased systemic blood pressure in a dose-dependent manner. Both responses to nicorandil were attenuated by glibenclamide (20 mg/kg, i.v.), an adenosine triphosphate (ATP)-dependent K(+) (K(ATP)) channel blocker. On the other hand, indomethacin (5 mg/kg, i.v.), a cyclooxygenase inhibitor, attenuated the vasodilation of retinal blood vessels, but not depressor response, to nicorandil and sodium nitroprusside. Pinacidil (1-300 microg kg(-1) min(-1), i.v.), a K(ATP) channel opener, also dilated retinal blood vessels and decreased systemic blood pressure. The responses to pinacidil were prevented by glibenclamide, but not by indomethacin. The vasodilation of retinal arteriole, but not depressor response, to sodium nitroprusside (1-30 microg kg(-1) min(-1), i.v.), a nitric oxide donor, was attenuated by indomethacin. These results suggest that nicorandil dilates retinal blood vessels through opening of K(ATP) channels and production of prostaglandins that are probably generated by nitric oxide.

  2. Comparative Finite Element Analysis of Short Implants and Lateralization of the Inferior Alveolar Nerve With Different Prosthesis Heights.

    Science.gov (United States)

    Jayme, Sérgio J; Ramalho, Paulo R; De Franco, Leonardo; Jugdar, Ricardo Elias; Shibli, Jamil Awad; Vasco, Marco A A

    2015-11-01

    The lateralization of the inferior alveolar nerve (LIAN) and short implants are efficient options for rehabilitation of the posterior atrophic mandible. However, the loss of bone leads to prosthesis with greater height and lever effect that in turn can have different impact on treatments. Through the finite element method, the present study tests the hypothesis that conventional implants placed under LIAN and short implants have similar risk of bone loss regarding variable height of the crown and that crown-to-implant ratio is not a reliable resource to evaluate risk in these treatments. Computed tomography scans of mandibles were processed and implants and prosthetic components were reverse engineered for reconstruction of three-dimensional models to simulate 3 elements fixed partial dentures supported by 2 osseointegrated implants. The models of implants were based on MK III implants (Nobel Biocare, Zurich, Switzerland) with 4 mm in diameter by 7 mm in length representing short implants, and 15 mm in length representing implants used in LIAN. The implant/crown ratio for short implants was 1:1.5, 1:2, and 1:2.5 and LIAN models were modeled with exactly the same prosthesis, resulting in implant/crown ratios of 1:0.67, 1:0.89, and 1:1.12. The results partially rejected the hypothesis that LIAN and short implants have similar risk of bone loss, showing that although LIAN results were better in the models evaluated, the variations in height had proportionally similar impact on both treatments and accepted the hypothesis that crown-to-implant ratio was not a reliable resource to evaluate risk.

  3. Immediate Loading of Fixed Complete Denture Prosthesis Supported by 4-8 Implants Placed Using Guided Surgery: A 5-Year Prospective Study on 66 Patients with 356 Implants.

    Science.gov (United States)

    Meloni, Silvio Mario; Tallarico, Marco; Pisano, Milena; Xhanari, Erta; Canullo, Luigi

    2017-02-01

    High primary implant stability is considered one of the main factors necessary for achieving predictable treatment outcomes with immediately loaded implant-supported screw-retained fixed complete denture prosthesis (FCDP). To evaluate the 5-year clinical and radiographic outcomes of immediately loaded implants placed in edentulous patients using computer-assisted template-guided surgery to support a FCDP. Patients in need to be restored with a FCDP in the mandible or maxilla were included in this prospective study/ and treated using computer-assisted template-guided surgery. Implant sites were prepared in order to achieve an insertion torque ranging between 35-45 Ncm in the mandible and 45-55 Ncm in the maxilla. A prefabricated screw-retained provisional prosthesis was delivered the day of the surgery. Outcomes were: implant and prosthesis cumulative survival rate (CSR), any complications, and peri-implant marginal bone loss (MBL). Sixty-six patients received 356 implants to support 68 FCDPs. Each patient received 4-8 implants. Seven implants failed in six patients, resulting in a CSR of 98.1%. Two definitive prostheses failed resulting in CSR of 97.1%. Mean MBL of 1.62 ± 0.41 mm was reported at the 5-year follow-up. Five implants (1.4%) showed a mean mesio-distal peri-implant bone loss greater than 3.0 mm and received nonsurgical therapy. immediately loaded implants placed in edentulous patients using computer-assisted template-guided surgery to support a FCDP is a valid treatment concept in the medium term follow-up, for edentulous patients. © 2016 Wiley Periodicals, Inc.

  4. Percutaneous closure of paravalvular leaks after transcatheter aortic valve implantation with Edwards SAPIEN prosthesis: a report of two cases.

    Science.gov (United States)

    Estévez-Loureiro, Rodrigo; Salgado-Fernández, Jorge; Vázquez-González, Nicolás

    2013-02-01

    Significant periprosthetic aortic regurgitation after transcatheter aortic valve implantation with Edwards SAPIEN prosthesis has become a major concern of this technique given its association with impaired survival. We report the successful closure of such defects using vascular occlusion devices with significant improvement in clinical status of patients.

  5. Detection of Blood Vessels in Retinal Fundus Images

    Directory of Open Access Journals (Sweden)

    Faraz Oloumi

    2014-07-01

    Full Text Available Detection of blood vessels in retinal fundus images is an important initial step in the development of systems for computer-aided diagnosis of pathologies of the eye. In this study, we perform multifeature analysis for the detection of blood vessels in retinal fundus images. The vessel detection techniques implemented include multiscale vesselness measures, Gabor filters, line operators, and matched filters. The selection of an appropriate threshold is crucial for accurate detection of retinal blood vessels. We evaluate an adaptive threshold selection method along with several others for this purpose. We also propose a postprocessing technique for removal of false-positive pixels around the optic nerve head. Values of the area under the receiver operating haracteristic curve of up to $0.961$ were obtained using the $20$ test images of the DRIVE database.

  6. Histopathological reaction over prosthesis surface covered with silicone and polyurethane foam implanted in rats.

    Science.gov (United States)

    Wagenführ-Júnior, Jorge; Ribas Filho, Jurandir Marcondes; Nascimento, Marcelo Mazza do; Ribas, Fernanda Marcondes; Wanka, Marcus Vinícius; Godoi, Andressa de Lima

    2012-12-01

    To evaluate whether polyurethane foam leads more intense foreign-body reaction than silicone foam. To compare the vascularization of the capsules surrounding the foam implants. To investigate if the capsule of polyurethane foam implanted has greater amount of collagen than that of silicone foam. Sixty-four young male Wistar rats were allocated into two groups: polyurethane foam and silicone foam. Subcutaneous discs were implanted into the dorsum of the animals in both groups. The capsules were assessed 28 days, two months, three months and six months postoperatively. Microscopic analysis with H&E stain was performed to evaluate the acute and chronic inflammatory process, foreign-body reaction and neovascularization. The analysis with picrosirius red was performed using the ImageProPlus software, to measure the number of vessels and collagen types I and III. There were no statistical differences between the two groups regarding the acute and chronic inflammatory processes. All rats from the polyurethane group, in all times, exhibited moderate or intense foreign-body reaction, with statistic significant difference (p=0.046) when compared with the silicone group, in which the reaction was either mild or nonexistent at two months. Vascular proliferation was significantly different between the groups at 28 days (p=0.0002), with the polyurethane group displaying greater neovascularization with H&E stain. Similar results were obtained with picrosirius red, which revealed in the polyurethane group a much greater number of vessels than in the silicone group (p=0.001). The collagen area was larger in the polyurethane group, significantly at 28 days (p=0.001) and at two months (p=0.030). Polyurethane foam elicited more intense foreign-body reaction when compared with silicone foam. The number of vessels was higher in the capsules of the polyurethane foam implants 28 days after the operation. The capsule of the polyurethane foam implants showed a greater amount of collagen

  7. Recovery of testicular blood flow following ligation of testicular vessels

    International Nuclear Information System (INIS)

    Pascual, J.A.; Villanueva-Meyer, J.; Salido, E.; Ehrlich, R.M.; Mena, I.; Rajfer, J.

    1989-01-01

    To determine whether initial ligation of the testicular vessels of the high undescended testis followed by a delayed secondary orchiopexy is a viable alternative to the classical Fowler-Stephens procedure, a series of preliminary experiments were conducted in the rat in which testicular blood flow was measured by the 133-xenon washout technique before, and 1 hour and 30 days after ligation of the vessels. In addition, testicular histology, and testis and sex-accessory tissue weights were measured in 6 control, 6 sham operated and 6 testicular vessel ligated rats 54 days after vessel ligation. The data demonstrate that ligation and division of the testicular blood vessels produce an 80 per cent decrease in testicular blood flow 1 hour after ligation of the vessels. However, 30 days later testis blood flow returns to the control and pre-treatment value. There were no significant changes in testis or sex-accessory tissue weights 54 days after vessel ligation. Histologically, 4 of the surgically operated testes demonstrated necrosis of less than 25 per cent of the seminiferous tubules while 1 testis demonstrated more than 75 per cent necrosis. The rest of the tubules in all 6 testes demonstrated normal spermatogenesis. From this study we conclude that initial testicular vessel ligation produces an immediate decrease in testicular blood flow but with time the collateral vessels are able to compensate and return the testis blood flow to its normal pre-treatment value. These preliminary observations lend support for the concept that initial ligation of the testicular vessels followed by a delayed secondary orchiopexy in patients with a high undescended testis may be a possible alternative to the classical Fowler-Stephens approach

  8. Short-term objective and subjective evaluation of small-diameter implants used to support and retain mandibular prosthesis.

    Science.gov (United States)

    Brandt, Robert; Hollis, Scott; Ahuja, Swati; Adatrow, Pradeep; Balanoff, William

    2012-01-01

    The introduction of small-diameter implants has provided dentists the means of providing edentulous and partially edentulous patients with immediate functioning transitional prostheses while definitive restorations are being fabricated. The successful use of these small-diameter implants for temporary stabilization of prostheses has led many clinicians to explore the option of using them as a definitive alternative, especially as the technique requires minimal time and also is economical for the patients. To date, there has been no study with multiple patients looking at both the subjective and objective outcomes of these small-diameter implants. Twenty-seven edentulous patients were enrolled in this study, seven of them were smokers. One-hundred and eight small-diameter (2.0 mm, MDL) implants were surgically placed in 24 edentulous mandibles. All implants were immediately loaded. The patients filled out a screening questionnaire and four subsequent questionnaires to test their satisfaction with the altered prosthesis at 6, 12, 18 and 24 months. The survival of the implants was also noted. Smokers had an implant survival of 79%. Non-smokers had an implant survival of 100%. The results of the questionnaire indicated an overall satisfaction with the implant-supported prosthesis.

  9. First percutaneous implantation of a completely tissue-engineered self-expanding pulmonary heart valve prosthesis using a newly developed delivery system: a feasibility study in sheep.

    Science.gov (United States)

    Spriestersbach, Hendrik; Prudlo, Antonia; Bartosch, Marco; Sanders, Bart; Radtke, Torben; Baaijens, Frank P T; Hoerstrup, Simon P; Berger, Felix; Schmitt, Boris

    2017-01-01

    In a European consortium, a decellularized tissue-engineered heart valve (dTEHV) based on vessel-derived cells, a fast-degrading scaffold and a self-expanding stent has been developed. The aim of this study was to demonstrate that percutaneous delivery is feasible. To implant this valve prosthesis transcutaneously into pulmonary position, a catheter delivery system was designed and custom made. Three sheep underwent transjugular prototype implantation. Intracardiac echocardiography (ICE), angiography and computed tomography (CT) were applied to assess the position, morphology, function and dimensions of the stented dTEHV. One animal was killed 3 h after implantation and two animals were followed up for 12 weeks. Explanted valves were analyzed macroscopically and microscopically. In all animals, the percutaneous implantation of the stented dTEHV was successful. The prototype delivery system worked at first attempt in all animals. In the first implantation a 22 F system was used: the valve was slightly damaged during crimping. Loading was difficult due to valve-catheter mismatch in volume. In the second and third implantation a 26 F system was used: the valves fitted adequately and stayed intact. Following implantation, these two valves showed moderate regurgitation due to insufficient coaptation. During follow-up, regurgitation increased due to shortened leaflets. At explantation, macroscopic and microscopic analysis confirmed the second and third valve to be intact. Histology revealed autologous recellularization of the decellularized valve after 12 weeks in vivo. It was demonstrated that completely in vitro tissue-engineered heart valves are thin and stable enough to be crimped and implanted transvenously into pulmonary position.

  10. Aging changes in the heart and blood vessels

    Science.gov (United States)

    ... vessels URL of this page: //medlineplus.gov/ency/article/004006.htm Aging changes in the heart and blood vessels To ... changes in the heart include deposits of the "aging pigment," lipofuscin . The heart muscle cells degenerate slightly. The valves inside the heart, which ...

  11. Patient’s satisfaction after 2-piece inflatable penile prosthesis implantation: An Italian multicentric study

    Directory of Open Access Journals (Sweden)

    Giorgio Gentile

    2016-03-01

    Full Text Available Introduction: Penile prosthesis implant represents a valuable solution for pts with severe erectile dysfunction (ED, non-responders to medical management. The aim of our study was to evaluate the satisfaction of patients (pts after 2-pieces inflatable penile prosthesis (IPP. Aim of the study: to evaluate safety, reliability and post-operative patient’s satisfaction after implantation of two-pieces IPP. Materials and Methods: This retrospective multicentric analysis concerns a group of 42 patients undergone 2-pieces IPP implantation from November 2005 to November 2013, in four Centers of proven experience. As a first step, a detailed review of all clinical reports was performed. Secondly, every patient was asked to fill the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS specifically modified, in order to assess their own satisfaction after surgery and, its impact on patient’s quality of sexual life. Results: 42 pts were evaluated (AMS-Ambicor: 28; Coloplast- Excell: 14; mean age, at time of operation: 60,7 years; mean follow up: 27,6 months; etiology of ED: vascular 23,8%, diabetes 19%, La Peyronie D. 7,1%, consequence of radical prostatectomy 31%, consequence of other pelvic surgery 11,9%, spinal trauma 7%. Mean operative time: 117 ± 58 min, mean postoperative hospital stay 3 ± 1,6 days. Post operative short-term complications: 4 pts (9,5%. Post operative long-term complications: 4 pts (9,5%. Long-term functional results (Questionnaire: 71% of pts (30 reported regular use of the prosthesis, at least 1 time/week, the satisfaction was good in 42% of pts (18, quite good in 33,3% (14, quite bad in 2,4% (1, very bad in 7,1% (3, 6 pts (14,4% didn’t answer. Conclusions: 2 pieces IPP appears to be associated with a low complication rate and good satisfaction of pts especially in the elderly. It also assures satisfactory rates of aesthetics and functional results.

  12. A Computational Model Predicting Disruption of Blood Vessel Development

    Science.gov (United States)

    Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a varie...

  13. Fluid and mass transport in a single lymphatic blood vessel

    International Nuclear Information System (INIS)

    Bestman, A.R.

    1987-08-01

    The problem considers the single blood vessel model in pulmonary circulation in the presence of gravitation and mass transfer. The tissue surrounding the blood vessel is modelled as a permeable medium distinct from the blood vessel which is a normal free space. On the assumption that the mass concentration varies slowly at the interface between the blood vessel and the tissue, the problem is tackled by asymptotic approximation. A crucial point of the analysis is the dependence of the flow variables on the permeability K of the tissue in a completely arbitrary manner. A primary conjecture of the study is the intimacy of the pathological pulmonary edema and the parameter K. (author). 4 refs

  14. An animal model to evaluate skin-implant-bone integration and gait with a prosthesis directly attached to the residual limb.

    Science.gov (United States)

    Farrell, Brad J; Prilutsky, Boris I; Kistenberg, Robert S; Dalton, John F; Pitkin, Mark

    2014-03-01

    Despite the number of advantages of bone-anchored prostheses, their use in patients is limited due to the lack of complete skin-implant integration. The objective of the present study was to develop an animal model that would permit both detailed investigations of gait with a bone-anchored limb prosthesis and histological analysis of the skin-implant-bone interface after physiological loading of the implant during standing and walking. Full-body mechanics of walking in two cats were recorded and analyzed before and after implantation of a percutaneous porous titanium pylon into the right tibia and attachment of a prosthesis. The rehabilitation procedures included initial limb casting, progressively increasing loading on the implant, and standing and locomotor training. Detailed histological analysis of bone and skin ingrowth into implant was performed at the end of the study. The two animals adopted the bone-anchored prosthesis for standing and locomotion, although loads on the prosthetic limb during walking decreased by 22% and 62%, respectively, 4months after implantation. The animals shifted body weight to the contralateral side and increased propulsion forces by the contralateral hindlimb. Histological analysis of the limb implants demonstrated bone and skin ingrowth. The developed animal model to study prosthetic gait and tissue integration with the implant demonstrated that porous titanium implants may permit bone and skin integration and prosthetic gait with a bone-anchored prosthesis. Future studies with this model will help optimize the implant and prosthesis properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. [Penile Flexiflate® Surgitek prosthesis explant and simultaneous three-component hydraulic Titan® Alpha 1 prosthesis implantation, with double incision technique in a patient with kidney and pancreas transplant].

    Science.gov (United States)

    Pavone, Carlo; Abbadessa, Daniela; Leto, Gioacchino; Giaimo, Rosa Maria; Ascoli, Riccardo; Usala, Manuela; Caruana, Giovanni

    2011-01-01

    We treated a 45 years old patient, suffering from diabetes mellitus since childhood, with retinal, neurovascular and kidney complications. In 1988, for erectile dysfunction (ED) resistant to medical injective treatment, the patient underwent ligation of the dorsal vein of the penis without any result. In 1989 a Flexiflate® hydraulic prosthesis was implanted with resolution of ED. In 2005 the patient underwent simultaneous kidney and pancreas transplant with a trans-laparotomic approach for end stage renal disease and diabetes mellitus. In 2009, because of the Flexiflate® Surgitek malfunction, the patient underwent explantation of the Flexiflate® prosthesis and simultaneous implantation of a Titan® Alpha 1 prosthesis with a double surgical approach. After a peno-scrotal incision and the explant of the Flexiflate® Surgitek, a Titan® Alpha 1 prosthesis was implanted with a double incision technique. The placement of two inflatable cylinders and the pump was performed by peno-scrotal approach. Instead, the prosthesis' reservoir was placed with a separate infra-pubic incision to avoid possible injury from a single trans-inguinal approach, due to the previous laparotomy. After follow-up at 9 months and 1 year the prosthesis was working well and the patient satisfied. We couldn't find any related paper in the literature and as far as we know this is the only report on a simultaneous explant/implant of penile prosthesis with a double surgical approach in a patient with kidney and pancreas transplant.

  16. En bloc resection and prosthesis implantation to treat malignant fibrous histiocytoma of the humerus.

    Science.gov (United States)

    Sun, Jun; Zhang, Ru-Ming; Zheng, Yu-Xin

    2017-08-01

    Malignant fibrous histiocytoma (MFH) of the bone is a rare tumor. Most studies comparing limb salvage and amputation have reported that limb salvage had no adverse effect on the long-term survival of patients. This study evaluates the oncological outcomes of limb salvage procedures that were used for 15 patients with MFH of the humerus. The aim of this study was to assess the functional and oncological outcomes of patients with malignant fibrous histiocytoma of the humerus after en bloc resection and prosthesis implantation. A retrospective review of the charts of 15 patients who had undergone resection of malignant fibrous histiocytoma of the humerus followed by reconstruction with prosthesis was used in this study. A functional evaluation was based on Enneking's modified system of the functional evaluation of surgical management for musculoskeletal tumors. Complications of the procedures were also analyzed. Eight men and 7 women at an average age of 52.9 years were included in the study. The tumor involved the distal humerus in 3 patients, the proximal humerus in 8 patients and the mid-shaft humerus in 4 patients. Excellent results were achieved in 4 patients, good to fair in 10 and poor in 1. One patient had local recurrence. Pulmonary metastases occurred in 6 patients. Limb salvage surgery with chemotherapy is a viable treatment option for patients with malignant fibrous histiocytoma of the humerus.

  17. Sexual Function and Quality of Life Before and After Penile Prosthesis Implantation Following Radial Forearm Flap Phalloplasty.

    Science.gov (United States)

    Young, Ezekiel E; Friedlander, Daniel; Lue, Kathy; Anele, Uzoma A; Khurgin, Jacob L; Bivalacqua, Trinity J; Burnett, Arthur L; Redett, Richard J; Gearhart, John P

    2017-06-01

    To provide sexual function and quality of life outcomes in patients with severe penile deficiency who underwent radial forearm flap phalloplasty with and without penile prosthesis implantation. Patients with history of severe penile deficiency who underwent microsurgical radial forearm flap phalloplasty with and without penile prosthesis implantation between 2007 and 2014 were identified. They completed a set of web-based validated questionnaires including the International Index of Erectile Function, the Pediatric Penile Perception Score, the Sexual Quality of Life for Men, and several items addressing general quality of life. Outcomes were compared between groups. Nine of the 12 identified patients who had prosthesis after phalloplasty and 4 out of the 7 phalloplasty-only patients completed the survey, resulting in an overall response rate of 68%. Among the phalloplasty-prosthesis patients, 66% reported current sexual activity and 78% reported regular masturbation, whereas 1 of the 4 phalloplasty-only patients reported both. Prosthesis patients scored notably higher in all domains of the International Index of Erectile Function except for sexual desire. In contrast, they demonstrated similar scores of penile perception, as well as general and sexual quality of life. Among patients who have undergone flap phalloplasty, the subsequent placement of penile prosthesis appears to effectively allow for both intercourse and masturbation, resulting in measurable improvements in orgasmic function, intercourse satisfaction, and overall sexual satisfaction. Despite these important benefits, prosthesis placement does not appear to result in improvements in penile perception scores, or general or sexual quality of life. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Design and Simulations of an Energy Harvesting Capable CMOS Pixel for Implantable Retinal Prosthesis

    Science.gov (United States)

    Ansaripour, Iman; Karami, Mohammad Azim

    2017-12-01

    A new pixel is designed with the capability of imaging and energy harvesting for the retinal prosthesis implant in 0.18 µm standard Complementary Metal Oxide Semiconductor technology. The pixel conversion gain and dynamic range, are 2.05 \\upmu{{V}}/{{e}}^{ - } and 63.2 dB. The power consumption 53.12 pW per pixel while energy harvesting performance is 3.87 nW in 60 klx of illuminance per pixel. These results have been obtained using post layout simulation. In the proposed pixel structure, the high power production capability in energy harvesting mode covers the demanded energy by using all available p-n junction photo generated currents.

  19. Carbon-carbon composites for orthopedic prosthesis and implants. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T D; Klett, J W; Strizak, J P [Oak Ridge National Lab., TN (United States); Baker, C [FMI, Biddeford, ME (United States)

    1998-01-21

    The prosthetic implant market is extensive. For example, because of arthritic degeneration of hip and knee cartilage and osteoporotic fractures of the hip, over 200,000 total joint replacements (TJRs) are performed in the United States each year. Current TJR devices are typically metallic (stainless steel, cobalt, or titanium alloy) and are fixed in the bone with polymethylacrylate (PMMA) cement. Carbon-carbon composite materials offer several distinct advantages over metals for TJR prosthesis. Their mechanical properties can be tailored to match more closely the mechanical properties of human bone, and the composite may have up to 25% porosity, the size and distribution of which may be controlled through processing. The porous nature of carbon-carbon composites will allow for the ingrowth of bone, achieving biological fixation, and eliminating the need for PMMA cement fixation.

  20. Bentall procedure 39 years after implantation of a Starr-Edwards Aortic Caged- Ball-Valve Prosthesis

    Science.gov (United States)

    2010-01-01

    We report a case of a male patient who received an implantation of a Starr-Edwards-caged-ball-valve-prosthesis in 1967. The surgery and postoperative course were without complications and the patient recovered well after the operation. For the next four decades, the patient remained asymptomatic - no restrictions on his lifestyle and without any complications. In 2006, 39 years after the initial operation, we performed a Bentall-Procedure to treat an aortic ascendens aneurysm with diameters of 6.0 × 6.5 cm: we explanted the old Starr-Edwards-aortic-caged-ball-valve-prosthesis and replaced the ascending aorta with a 29 mm St.Jude Medical aortic-valve-composite-graft and re-implanted the coronary arteries. This case represents the longest time period between Starr-Edwards-caged-ball-valve-prothesis-implantation and Bentall-reoperation, thereby confirming the excellent durability of this valve. PMID:20298579

  1. Bentall procedure 39 years after implantation of a Starr-Edwards Aortic Caged- Ball-Valve Prosthesis

    Directory of Open Access Journals (Sweden)

    Sohns Christian

    2010-03-01

    Full Text Available Abstract We report a case of a male patient who received an implantation of a Starr-Edwards-caged-ball-valve-prosthesis in 1967. The surgery and postoperative course were without complications and the patient recovered well after the operation. For the next four decades, the patient remained asymptomatic - no restrictions on his lifestyle and without any complications. In 2006, 39 years after the initial operation, we performed a Bentall-Procedure to treat an aortic ascendens aneurysm with diameters of 6.0 × 6.5 cm: we explanted the old Starr-Edwards-aortic-caged-ball-valve-prosthesis and replaced the ascending aorta with a 29 mm St.Jude Medical aortic-valve-composite-graft and re-implanted the coronary arteries. This case represents the longest time period between Starr-Edwards-caged-ball-valve-prothesis-implantation and Bentall-reoperation, thereby confirming the excellent durability of this valve.

  2. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Sayan; Banerjee, Moloy, E-mail: moloy_kb@yahoo.com

    2015-01-15

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (z{sub offset}), particle size (d{sub p}) and its magnetic property (χ) and the magnitude of current (I) on the “capture efficiency” (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels. - Highlights: • Two counter rotating vortices forces the fluid flow back through the more viscous region. • The existence of strong recirculation zone just downstream side of the occlusion. • Configuration 4 produces the better efficient MDT system. • Modified Casson model predicts the highest value of CE, whereas the generalized power law gives

  3. Blood vessel damage correlated with irradiance for in vivo vascular targeted photodynamic therapy

    Science.gov (United States)

    Zhang, Jinde; Tan, Zou; Niu, Xiangyu; Lin, Linsheng; Lin, Huiyun; Li, Buhong

    2016-10-01

    Vascular targeted photodynamic therapy (V-PDT) has been widely utilized for the prevention or treatment of vascular-related diseases, including age-related macular degeneration, port-wine stains and prostate cancer. In order to quantitative assessment the blood vessel damage during V-PDT, nude mice were implanted with Titanium dorsal skin window chambers for in vivo V-PDT studies. For treatments, various irradiances including 50, 75, 100 and 200 mW/cm2 provided by a 532 nm semiconductor laser were performed with the same total light dose of 30 J/cm2 after the mice were intravenously injection of Rose Bengal for 25 mg/Kg body weight. Laser speckle imaging and microscope were used to monitor blood flow dynamics and vessel constriction during and after V-PDT, respectively. The V-PDT induced vessel damages between different groups were compared. The results show that significant difference in blood vessel damage was found between the lower irradiances (50, 75 and 100 mW/cm2) and higher irradiance (200 mW/cm2), and the blood vessel damage induced by V-PDT is positively correlated with irradiance. This study implies that the optimization of irradiance is required for enhancing V-PDT therapeutic efficiency.

  4. A novel microporous polyurethane vascular graft: in vivo evaluation of the UTA prosthesis implanted as infra-renal aortic substitute in dogs.

    Science.gov (United States)

    Marois, Y; Akoum, A; King, M; Guidoin, R; von Maltzahn, W; Kowligi, R; Eberhart, R C; Teijeira, F J; Verreault, J

    1993-01-01

    A novel microporous polyurethane blood conduit developed at the University of Texas at Arlington was implanted as an infra-renal substitute in dogs. The prosthesis was fabricated by precipitating a solution of the polymer with dry nitrogen onto a rotating mandrel. The grafts were sterilized either by gamma radiation (series I) or ethylene oxide (series II); they were implanted for the following prescheduled periods: 4, 24, 48 hours, and 1 week (short-term) and 2, 4 weeks, 3 and 6 months (medium-term). The thrombohematological characteristics of each animal were evaluated prior to implantation and confirmed that the index of blood coagulability was normal. In the short-term group, five out of eight grafts were patent and three were partially occluded; four grafts in the medium-term group were patent; one was partially occluded; and three were thrombosed at retrieval. One week after implantation, the prostheses were surrounded by an external capsule, which was present mainly at the two anastomoses. The external capsule covered the entire graft at 3 months. No kinking of the grafts was observed and the presence of a mild yellow stain related to bilirubin uptake was detected at 2 weeks, 1, 3, and 6 months. Histological studies have revealed the formation of a thin internal capsule at both anastomoses, 2 weeks postimplantation, which was not anchored to the graft wall. In the medium-term group, the thrombosed grafts failed to develop an internal capsule, whereas the patent graft exhibited a thick internal capsule made of neocollagenous tissue over the entire graft. This new microporous polyurethane prosthesis did not perform satisfactorily as an infra-renal substitute in dogs and its in vivo stability requires further assessment. Thus, the concept of a polyurethane with closed pores does not achieve what was anticipated.

  5. Application of digital diagnostic impression, virtual planning, and computer-guided implant surgery for a CAD/CAM-fabricated, implant-supported fixed dental prosthesis: a clinical report.

    Science.gov (United States)

    Stapleton, Brandon M; Lin, Wei-Shao; Ntounis, Athanasios; Harris, Bryan T; Morton, Dean

    2014-09-01

    This clinical report demonstrated the use of an implant-supported fixed dental prosthesis fabricated with a contemporary digital approach. The digital diagnostic data acquisition was completed with a digital diagnostic impression with an intraoral scanner and cone-beam computed tomography with a prefabricated universal radiographic template to design a virtual prosthetically driven implant surgical plan. A surgical template fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM) was used to perform computer-guided implant surgery. The definitive digital data were then used to design the definitive CAD/CAM-fabricated fixed dental prosthesis. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. Bone mineral density after implantation of a femoral neck hip prosthesis--a prospective 5 year follow-up.

    Science.gov (United States)

    Steens, Wolfram; Boettner, Friedrich; Bader, Rainer; Skripitz, Ralf; Schneeberger, Alberto

    2015-08-12

    Bone resorption in the proximal femur due to stress shielding has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to prospectively investigate the in vivo changes of bone-mineral density as a parameter of bone remodeling around a short, femoral neck prosthesis over the first 5 years following implantation. The secondary goal was to report on its clinical outcome. We are reporting on the changes of bone mineral density of the proximal femur and the clinical outcome up to five years after implantation of a short femoral neck prosthesis. Bone mineral density was determined using dual energy x-ray absorptiometry, performed 10 days, three, 12 and 60 months after surgery. 20 patients with a mean age of 47 years (range 17 to 65) were clinically assessed using the Harris Hip Score. The WOMAC was used as a patient-relevant outcome-measure. In contrast to conventional implants DEXA-scans overall revealed a slight increase of bone mineral density in the proximal femur in the 12 months following the implantation. The Harris Hip Score improved from an average preoperative score of 46 to a postoperative score at 12 months of 91 points and 95 points at 60 months, the global WOMAC index from 5.3 preoperatively to 0.8 at 12 months and 0.6 at 60 months postoperatively. At 60 months after implantation of a short femoral neck prosthesis, all regions except one (region of interest #5) showed no significant changes in BMD compared to baseline measurements at 10 days which is less to the changes in bone mineral density seen in conventional implants.

  7. [15-year results following implantation of a stem type AML hip prosthesis].

    Science.gov (United States)

    Schwerter, K; Meyenberg, A; Sander, K; Layher, F; Roth, A

    2013-06-01

    The trend in arthroplasty of the hip joint to implement new models is partly based on theoretical considerations. In order to verify to which extent the philosophy of individual models is ultimately successful, the presentation of long-term results is required. In the years 1991 and 1992, 433 patients with primary implantation of an uncemented total hip replacement in primary coxarthrosis with a stem type AML (anatomic medullary locking) were treated surgically. 283 of them got a cementless cup type Duraloc. In 311 (71.8 %) patients the mean survival rate of the prosthesis could be determined at a mean follow-up of 15.5 years. 145 (33.5 %) patients were followed up completely both clinically and radiologically. Radiographically, the stem position, changes of the periprosthetic bone of the stem and the cup, as well as the wear of the cups were examined. The cumulative survival rate of the AML stem after 15.5 years was 97.5 %, of the Duraloc cup 88.2 %. The clinical results of the hip scores according to Harris and Merle d'Aubigné were good and excellent and patient satisfaction was very high. There was no relationship between stem position, stress shielding and surrounding lyses at the femur and the acetabulum and survival of stem or cup. There was no correlation between inlay wear and survival of the Duraloc cup. A subsiding of the stem in 2 cases had no effect on the clinical symptoms and quality of life. The press-fit implanted AML stem and the Duraloc cup revealed very good results during the investigation period. Like other implants, the survival rate is limited at the presented implant mainly by the cup. Georg Thieme Verlag KG Stuttgart · New York.

  8. Three-dimensional photoacoustic imaging of blood vessels in tissue

    NARCIS (Netherlands)

    Hoelen, C.G.A.; de Mul, F.F.M.; Pongers, R.; Dekker, A.

    1998-01-01

    We applied photoacoustics as a tissue tomography technique for the detection of blood concentrations, e.g., angiogenesis around tumors. We imaged blood vessels in highly scattering samples, using 532-nm light, to depths of ,1 cm. The samples were real tissue (chicken breast) or 10% dilutions of

  9. Patient-prosthesis mismatch and left ventricular remodelling after implantation of Shelhigh SuperStentless aortic valve prostheses.

    Science.gov (United States)

    Germing, A; Lindstaedt, M; Holt, S; Reber, D; Mügge, A; Laczkovics, A; Fritz, M

    2008-08-01

    Aortic valve replacement is a standard procedure for the treatment of severe aortic valve stenosis. Due to lower flow velocities stentless valves are associated with a more effective regression of left ventricular hypertrophy in comparison to stented valves. However, mismatch between body surface area and valve size supports unfavourable hemodynamic results. The aim of the study was to analyze hemodynamic parameters by echocardiography after implantation of the Shelhigh SuperStentless bioprosthesis and to analyze the occurrence of patient-prosthesis mismatch and left ventricular remodelling in this specific valve type. A total of 20 patients with severe aortic stenosis underwent implantation of a Shelhigh Super Stentless prosthesis. Clinical and echocardiographic assessment was done prior to, immediate after and six months after surgery. All surgical procedures were successful, no surgery-related complication was documented perioperatively. One patient died after development of multiorgan failure. Echocardiography during the first eight days after surgery showed mean gradients of 16 mmHg, mean valve orifice areas of 1.8 cm(2) and indexed effective orifice areas at 0.95 cm(2)/m(2). Six-months follow-up data were obtained in 19/20 patients. There were no relevant changes in echocardiographic hemodynamic findings at the time of follow-up measurements. Significant regression of left ventricular hypertrophy was shown (P=0.0088). A patient-prosthesis mismatch occurred in one patient (0.54 cm(2)/m(2)). No recurrent symptoms were documented. Patient-prosthesis mismatch after implantation of SuperStentless Shelhigh prosthesis is rare. A significant regression of left ventricular hypertrophy could be shown after six months. Hemodynamic valve function assessed by echocardiography may be predicted early after surgery.

  10. Visual evoked potential in RCS rats with Okayama University-type retinal prosthesis (OUReP™) implantation.

    Science.gov (United States)

    Alamusi; Matsuo, Toshihiko; Hosoya, Osamu; Uchida, Tetsuya

    2017-06-01

    Photoelectric dye-coupled polyethylene film, designated Okayama University type-retinal prosthesis or OUReP™, generates light-evoked surface electric potentials and stimulates neurons. The dye-coupled films or plain films were implanted subretinally in both eyes of 10 Royal College of Surgeons rats with hereditary retinal dystrophy at the age of 6 weeks. Visual evoked potentials in response to monocular flashing light stimuli were recorded from cranially-fixed electrodes, 4 weeks and 8 weeks after the implantation. After the recording, subretinal film implantation was confirmed histologically in 7 eyes with dye-coupled films and 7 eyes with plain films. The recordings from these 7 eyes in each group were used for statistical analysis. The amplitudes of visual evoked potentials in the consecutive time points from 125 to 250 ms after flash were significantly larger in the 7 eyes with dye-coupled film implantation, compared to the 7 eyes with plain film implantation at 8 weeks after the implantation (P prosthesis, gave rise to visual evoked potential in response to flashing light.

  11. Computer-designed selective laser sintering surgical guide and immediate loading dental implants with definitive prosthesis in edentulous patient: A preliminary method.

    Science.gov (United States)

    Giacomo, Giovanni Di; Silva, Jorge; Martines, Rodrigo; Ajzen, Sergio

    2014-01-01

    The aim of this study was to analyze a preliminary method of immediately loading dental implants and a definitive prosthesis based on the computer-aided design/computer-aided manufacturing systems, after 2 years of clinical follow-up. The study comprised one patient in good general health with edentulous maxilla. Cone beam computer tomography (CBCT) was performed using a radiographic template. The surgical plan was made using the digital imaging and communications in medicine protocol with ImplantViewer (version 1.9, Anne Solutions, Sao Paulo, SP, Brazil), the surgical planning software. These data were used to produce a selective laser sintering surgical template. A maxilla prototype was used to guide the prosthesis technician in producing the prosthesis. Eight dental implants and a definitive prosthesis were installed on the same day. A post-operative CBCT image was fused with the image of the surgical planning to calculate the deviation between the planned and the placed implants positions. Patient was followed for 2 years. On average, the match between the planned and placed angular deviation was within 6.0 ± 3.4° and the difference in coronal deviation was 0.7 ± 0.3 mm. At the end of the follow-up, neither the implant nor the prosthesis was lost. Considering the limited samples number, it was possible to install the dental implants and a definitive prosthesis on the same day with success.

  12. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit

    2006-01-01

    for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure......PURPOSE: To assess the relative influence of genetic and environmental effects on retinal vessel diameters and blood pressure in healthy adults, as well as the possible genetic connection between these two characteristics. METHODS: In 55 monozygotic and 50 dizygotic same-sex healthy twin pairs......%-80%) for CRAE, 83% (95% CI: 73%-89%) for CRVE, and 61% (95% CI: 44%-73%) for mean arterial blood pressure (MABP). Retinal artery diameter decreased with increasing age and increasing arterial blood pressure. Mean vessel diameters in the population were 165.8 +/- 14.9 microm for CRAE, 246.2 +/- 17.7 microm...

  13. Estimation of center line and diameter of brain blood vessel using three-dimensional blood vessel matching method with head three-dimensional CTA image

    International Nuclear Information System (INIS)

    Maekawa, Masashi; Shinohara, Toshihiro; Nakayama, Masato; Nakasako, Noboru

    2010-01-01

    To support and automate the brain blood vessel disease diagnosis, a novel method to obtain the center line and the diameter of a blood vessel is proposed with a three-dimensional head computed tomographic angiography (CTA) image. Although the line thinning processing with distance transform or gray information is generally used to obtain the blood vessel center line, this method is not essentially one to obtain the center line and tends to yield extra lines depending on CTA images. In this study, the center line of the blood vessel is obtained by tracing the vessel. The blood vessel is traced by sequentially estimating the center point and direction of the blood vessel. The center point and direction of the blood vessel are estimated by taking the correlation between the blood vessel and a solid model of the blood vessel that is designed by considering noise influence. In addition, the vessel diameter is also estimated by correlating the blood vessel and the blood vessel model of which the diameter is variable. The validity of the proposed method is confirmed by experimentally applied the proposed method to an actual three-dimensional head CTA image. (author)

  14. Autoinflation Leading to Failure of Two-Piece Ambicor Implantable Penile Prosthesis: An Outcome from a Methodical Treatment of Recalcitrant Stuttering Priapism

    Directory of Open Access Journals (Sweden)

    R. Charles Welliver

    2014-01-01

    Full Text Available Introduction. We present the case of a patient who received a two-piece Ambicor penile prosthesis for idiopathic recurrent “stuttering” priapism refractory to other treatment options. The patient returned unable to deflate the device due to an interesting anatomically induced mechanical failure. Aims. To describe the method and findings of this inflatable prosthesis failure. Results. Prosthesis failure occurred due to restrictive corporal diameter and the unique characteristics of fluid reservoir location in the two-piece inflatable prosthesis. The patient was successfully converted to a semirigid prosthesis with resolution of the pain that was due to his prosthesis autoinflation. Conclusion. Stuttering priapism remains a challenging clinical problem. Penile implantation is a reasonable long-term solution in a patient refractory to less invasive options. In patients with fibrotic corpora, a malleable device should be considered (at least temporarily if unable to dilate comfortably to 13 mm.

  15. Proximal tendon-prosthesis junction for active tendon implants of the hand: a biomechanical comparison of 2 techniques.

    Science.gov (United States)

    Thompson, Matthew J; Owen, John R; McDowell, Charles L; Wayne, Jennifer S

    2015-01-01

    To study the biomechanical characteristics (percent stretch, stiffness, and ultimate load) of 2 tendon-prosthesis techniques used to connect the proximal tendon stump to silicone active tendon implants used in reconstruction of flexor tendons. We evaluated percent stretch following cyclic loading and at failure, stiffness during load to failure, and ultimate load of 16 tendon-prosthesis junctions using cadaveric canine flexor digitorum profundus tendons to re-create 2 junction techniques: the tendon loop (TL) and the polyester weave (PW). The TL junction showed greater percent stretch at a static load of 2 N, following 500 cycles of loading between 2 N and 50 N, and at peak load. The PW junction displayed greater stiffness from 50 to 150 N during load to failure. Both junctions failed at a mean ultimate load greater than 220 N. The described proximal junction techniques for active tendon implants were strong enough to resist early active motion in the immediate postoperative period without significant elongation. The PW technique displayed greater stiffness and ultimate load compared with the TL. Data on tendon-prosthesis characteristics of these 2 methods may aid the surgeon in choosing which junction technique to use, during surgical tensioning decisions, and in considering activity protocols after surgery. These data may also serve as a baseline for further investigations regarding active tendon implants. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  16. Tracking blood vessels in human forearms using visual servoing

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Ellekilde, Lars-Peter; Hansen, Morten

    Drawing an average of more than 2 blood sample per Danish citizen per year increases the demand for an automatic blood sampling method. This paper presents a proof of concept to one of the main challenges in making a fully automated blood sampling procedure, namely: the patient movement compensat......Drawing an average of more than 2 blood sample per Danish citizen per year increases the demand for an automatic blood sampling method. This paper presents a proof of concept to one of the main challenges in making a fully automated blood sampling procedure, namely: the patient movement...... compensation. By using images taken with near-infrared light to locate the blood vessels in a human forearm and using the same images to detects movements of the arm, this paper shows that it is possible make a robot arm, potentially equipped with a needle for drawing the blood, compensate for the movements...

  17. Acrolein generation stimulates hypercontraction in isolated human blood vessels.

    Science.gov (United States)

    Conklin, D J; Bhatnagar, A; Cowley, H R; Johnson, G H; Wiechmann, R J; Sayre, L M; Trent, M B; Boor, P J

    2006-12-15

    Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H(2)O(2) exposure (1 microM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 microM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca(2+) to hypercontraction. Acrolein or allylamine but not H(2)O(2), benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca(2+)-free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension.

  18. Acrolein generation stimulates hypercontraction in isolated human blood vessels

    International Nuclear Information System (INIS)

    Conklin, D.J.; Bhatnagar, A.; Cowley, H.R.; Johnson, G.H.; Wiechmann, R.J.; Sayre, L.M.; Trent, M.B.; Boor, P.J.

    2006-01-01

    Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H 2 O 2 exposure (1 μM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 μM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca 2+ to hypercontraction. Acrolein or allylamine but not H 2 O 2 , benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca 2+ -free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension

  19. A Novel Technique of Fabricating a Modified Removable Provisional Prosthesis over an Autologous Bone Grafted Maxillary Anterior Edentulous Segment Prior to Implant Placement.

    Science.gov (United States)

    Andonissamy, Leoney; Vidhya, N Sri

    2017-09-01

    Implant dentistry has provided a lot of surgical as well as prosthetic techniques for improving the success of the implants. The surgical technique commonly followed now prior to implant placement is bone grafting procedure. One of the commonest techniques is the use of autologous block graft harvested from mandibular chin region. However, interference in healing as well as excessive bone resorption due to the use of removable provisional prosthesis over the bone grafted region has been commonly observed/reported. Hence now-a-days, fixed provisional prosthesis is preferred over removable provisional prosthesis for the added advantages of superior aesthetics and patient acceptance. This article highlights a new technique of fabricating removable provisional prosthesis, which is superior in aesthetics and strength, consumes less chair time and exerts zero pressure onto the grafted site.

  20. Characterization of a Polymer-Based, Fully Organic Prosthesis for Implantation into the Subretinal Space of the Rat.

    Science.gov (United States)

    Antognazza, Maria Rosa; Di Paolo, Mattia; Ghezzi, Diego; Mete, Maurizio; Di Marco, Stefano; Maya-Vetencourt, José Fernando; Maccarone, Rita; Desii, Andrea; Di Fonzo, Fabio; Bramini, Mattia; Russo, Angela; Laudato, Lucia; Donelli, Ilaria; Cilli, Michele; Freddi, Giuliano; Pertile, Grazia; Lanzani, Guglielmo; Bisti, Silvia; Benfenati, Fabio

    2016-09-01

    Replacement strategies arise as promising approaches in case of inherited retinal dystrophies leading to blindness. A fully organic retinal prosthesis made of conjugated polymers layered onto a silk fibroin substrate is engineered. First, the biophysical and surface properties are characterized; then, the long-term biocompatibility is assessed after implantation of the organic device in the subretinal space of 3-months-old rats for a period of five months. The results indicate a good stability of the subretinal implants over time, with preservation of the physical properties of the polymeric layer and a tight contact with the outer retina. Immunoinflammatory markers detect only a modest tissue reaction to the surgical insult and the foreign body that peaks shortly after surgery and progressively decreases with time to normal levels at five months after implantation. Importantly, the integrity of the polymeric layer in direct contact with the retinal tissue is preserved after five months of implantation. The recovery of the foreign-body tissue reaction is also associated with a normal b-wave in the electroretinographic response. The results demonstrate that the device implanted in nondystrophic eyes is well tolerated, highly biocompatible, and suitable as retinal prosthesis in case of photoreceptor degeneration. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Comparison and Combination of Dual-Energy- and Iterative-Based Metal Artefact Reduction on Hip Prosthesis and Dental Implants.

    Science.gov (United States)

    Bongers, Malte N; Schabel, Christoph; Thomas, Christoph; Raupach, Rainer; Notohamiprodjo, Mike; Nikolaou, Konstantin; Bamberg, Fabian

    2015-01-01

    To compare and combine dual-energy based and iterative metal artefact reduction on hip prosthesis and dental implants in CT. A total of 46 patients (women:50%,mean age:63±15years) with dental implants or hip prostheses (n = 30/20) were included and examined with a second-generation Dual Source Scanner. 120kV equivalent mixed-images were derived from reconstructions of the 100/Sn140kV source images using no metal artefact reduction (NOMAR) and iterative metal artefact reduction (IMAR). We then generated monoenergetic extrapolations at 130keV from source images without IMAR (DEMAR) or from source images with IMAR, (IMAR+DEMAR). The degree of metal artefact was quantified for NOMAR, IMAR, DEMAR and IMAR+DEMAR using a Fourier-based method and subjectively rated on a five point Likert scale by two independent readers. In subjects with hip prosthesis, DEMAR and IMAR resulted in significantly reduced artefacts compared to standard reconstructions (33% vs. 56%; for DEMAR and IMAR; respectively, pdental implants only IMAR showed a significant reduction of artefacts whereas DEMAR did not (71%, vs. 8% pprosthesis: 47%, dental implants 18%; both pdental implants, compared to a dual energy based method. The combination of DE-source images with IMAR and subsequent monoenergetic extrapolation provides an incremental benefit compared to both single methods.

  2. Sutureless implantation of the perceval s aortic valve prosthesis through right anterior minithoracotomy.

    Science.gov (United States)

    Gilmanov, Daniyar; Miceli, Antonio; Bevilacqua, Stefano; Farneti, Pierandrea; Solinas, Marco; Ferrarini, Matteo; Glauber, Mattia

    2013-12-01

    Many new, less invasive strategies are proposed for aortic valve operation in elderly patients. Rapid deployment sutureless aortic valve prosthesis has been recently introduced. We analyzed our experience with a sutureless valve implanted through a minimally invasive approach. A retrospective observational study with prospectively registered data was conducted on 137 patients undergoing aortic valve replacement through a right anterior minithoracotomy. Between April 2011 and January 2013, 137 consecutive patients underwent aortic valve replacement with a recently introduced, rapid deployment, sutureless pericardial valve in minithoracotomy access (47 men; mean age, 76.6 ± 7.1 years). There were 35 obese patients with a body mass index of more than 30 kg/m(2). Mean logistic EuroSCORE I was 10.0; 74 (54%) patients were in New York Heart Association functional class III and IV. In all, 19 (13.9%), 45 (32.8%), and 73 (53.3%) patients received 21-, 23-, and 25-mm valve prostheses, respectively. The mean aortic cross-clamp and cardiopulmonary bypass times were 59.3 ± 19 min and 92.3 ± 27 min, respectively. No operative mortality occurred. Median stay in the intensive care unit was 1 day, with assisted ventilation necessary for a median of 6 hours. Three cases of postoperative ischemic stroke were observed (1 patient with a previous history of an ischemic cerebral event). Median hospital length of stay was 6 days. A sutureless valve for minimally invasive aortic valve replacement is a feasible, effective, and safe tool. Ultimately amplifying indications for less invasive aortic valve replacement in a high surgical risk subset of patients, it can become a valid alternative for transcatheter aortic valve implantation. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Automatic segmentation of blood vessels from retinal fundus images ...

    Indian Academy of Sciences (India)

    through image processing and data mining techniques. Retinal image data, which is given as input for data mining process is considered as Big Data since every pixel forms a tuple. Blood vessel network is segmented through color space conversion and channel extraction, image pre-processing, Gabor filtering, application ...

  4. Synthesis of cobalt alloy through smelting method and its characterization as prosthesis bone implant

    Energy Technology Data Exchange (ETDEWEB)

    Aminatun,, E-mail: ami-sofijan@yahoo.co.id; Putri, N.S Efinda, E-mail: ami-sofijan@yahoo.co.id; Indriani, Arista, E-mail: ami-sofijan@yahoo.co.id; Himawati, Umi, E-mail: ami-sofijan@yahoo.co.id; Hikmawati, Dyah, E-mail: ami-sofijan@yahoo.co.id; Suhariningsih, E-mail: ami-sofijan@yahoo.co.id [Department of physics, Faculty of Science and Technology, Airlangga University (Indonesia)

    2014-09-25

    Cobalt-based alloys are widely used as total hip and knee replacements because of their excellent properties, such as corrosion resistance, fatigue strength and biocompatibility. In this work, cobalt alloys with variation of Cr (28.5; 30; 31.5; 33, and 34.5% wt) have been synthesized by smelting method began with the process of compaction, followed by smelting process using Tri Arc Melting Furnace at 200A. Continued by homogenization process at recrystallization temperature (1250° C) for 3 hours to allow the atoms diffuses and transform into γ phase. The next process is rolling process which is accompanied by heating at 1200° C for ± 15 minutes and followed by quenching. This process is repeated until the obtained thickness of ± 1 mm. The evaluated material properties included microstructure, surface morphology, and hardness value. It was shown that microstructure of cobalt alloys with variation of Cr is dominant by γ phase, thus making the entire cobalt alloys have high hardness. It was also shown from the surface morphology of entire cobalt alloys sample indicated the whole process of synthesis that had good solubility were at flat surface area. Hardness value test showed all of cobalt alloys sample had high hardness, just variation of 33% Cr be in the range of ASTMF75, it were 345,24 VHN which is potential to be applied as an implant prosthesis.

  5. Technique for systematic bone reduction for fixed implant-supported prosthesis in the edentulous maxilla.

    Science.gov (United States)

    Bidra, Avinash S

    2015-06-01

    Bone reduction for maxillary fixed implant-supported prosthodontic treatment is often necessary to either gain prosthetic space or to conceal the prosthesis-tissue junction in patients with excessive gingival display (gummy smile). Inadequate bone reduction is often a cause of prosthetic failure due to material fractures, poor esthetics, or inability to perform oral hygiene procedures due to unfavorable ridge lap prosthetic contours. Various instruments and techniques are available for bone reduction. It would be helpful to have an accurate and efficient method for bone reduction at the time of surgery and subsequently create a smooth bony platform. This article presents a straightforward technique for systematic bone reduction by transferring the patient's maximum smile line, recorded clinically, to a clear radiographic smile guide for treatment planning using cone beam computed tomography (CBCT). The patient's smile line and the amount of required bone reduction are transferred clinically by marking bone with a sterile stationery graphite wood pencil at the time of surgery. This technique can help clinicians to accurately achieve the desired bone reduction during surgery, and provide confidence that the diagnostic and treatment planning goals have been achieved. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. Gene expression analysis in human breast cancer associated blood vessels.

    Directory of Open Access Journals (Sweden)

    Dylan T Jones

    Full Text Available Angiogenesis is essential for solid tumour growth, whilst the molecular profiles of tumour blood vessels have been reported to be different between cancer types. Although presently available anti-angiogenic strategies are providing some promise for the treatment of some cancers it is perhaps not surprisingly that, none of the anti-angiogenic agents available work on all tumours. Thus, the discovery of novel anti-angiogenic targets, relevant to individual cancer types, is required. Using Affymetrix microarray analysis of laser-captured, CD31-positive blood vessels we have identified 63 genes that are upregulated significantly (5-72 fold in angiogenic blood vessels associated with human invasive ductal carcinoma (IDC of the breast as compared with blood vessels in normal human breast. We tested the angiogenic capacity of a subset of these genes. Genes were selected based on either their known cellular functions, their enriched expression in endothelial cells and/or their sensitivity to anti-VEGF treatment; all features implicating their involvement in angiogenesis. For example, RRM2, a ribonucleotide reductase involved in DNA synthesis, was upregulated 32-fold in IDC-associated blood vessels; ATF1, a nuclear activating transcription factor involved in cellular growth and survival was upregulated 23-fold in IDC-associated blood vessels and HEX-B, a hexosaminidase involved in the breakdown of GM2 gangliosides, was upregulated 8-fold in IDC-associated blood vessels. Furthermore, in silico analysis confirmed that AFT1 and HEX-B also were enriched in endothelial cells when compared with non-endothelial cells. None of these genes have been reported previously to be involved in neovascularisation. However, our data establish that siRNA depletion of Rrm2, Atf1 or Hex-B had significant anti-angiogenic effects in VEGF-stimulated ex vivo mouse aortic ring assays. Overall, our results provide proof-of-principle that our approach can identify a cohort of

  7. A comparative analysis of internal bone remodelling concepts in a novel implant for direct skeletal attachment of limb prosthesis evaluation: A finite element analysis.

    Science.gov (United States)

    Prochor, Piotr; Sajewicz, Eugeniusz

    2018-03-01

    Nowadays, numerous internal bone remodelling concepts are under development, in order to estimate long-term functionality of implants by evaluating the intensity of stress-shielding effect. This effect is also analysed for the implants for direct skeletal attachment, considered as a better exoprosthesis fixation method than prosthetic sockets. Most of bone remodelling approaches are based on basic concepts, differing with certain assumptions, which may affect the accuracy of the results. This article compares commonly used internal bone remodelling concepts and evaluates the functionality of the proposed Limb Prosthesis Osseointegrated Fixation System for direct skeletal attachment of limb prosthesis in comparison with two currently available implants: the Intraosseous Transcutaneous Amputation Prosthesis and the Osseointegrated Prostheses for the Rehabilitation of Amputees. Three concepts were chosen: without and with lazy zone and with the use of quadratic formula which considers bone overloading. Therefore, three finite element models were created with identical femur implanted with each of analysed implants. The implants were loaded with loads that refer to two stages of gait cycle (heel strike and toe-off). The analysed concepts have given similar results, allowing to assume that each of them can be successfully used to estimate internal bone remodelling around analysed implants for direct skeletal attachment of limb prosthesis. The results also present higher functionality of the proposed implant for direct skeletal attachment of limb prosthesis due to a significant reduction in stress-shielding in the analysed areas around implant in comparison with the Intraosseous Transcutaneous Amputation Prosthesis and the Osseointegrated Prostheses for the Rehabilitation of Amputees. It suggests that the proposed design is a better alternative to the currently used solutions.

  8. Tilted and short implants supporting fixed prosthesis in an atrophic maxilla: a 3D-FEA biomechanical evaluation.

    Science.gov (United States)

    Almeida, Erika O; Rocha, Eduardo P; Freitas Júnior, Amilcar C; Anchieta, Rodolfo B; Poveda, Ronald; Gupta, Nikhil; Coelho, Paulo G

    2015-01-01

    This study compared the biomechanical behavior of tilted long implant and vertical short implants to support fixed prosthesis in an atrophic maxilla. The maxilla model was built based on a tomographic image of the patient. Implant models were based on micro-computer tomography imaging of implants. The different configurations considered were M4S, four vertical anterior implants; M4T, two mesial vertical implants and two distal tilted (45°) implants in the anterior region of the maxilla; and M6S, four vertical anterior implants and two vertical posterior implants. Numerical simulation was carried out under bilateral 150 N loads applied in the cantilever region in axial (L1) and oblique (45°) (L2) direction. Bone was analyzed using the maximum and minimum principal stress (σmax and σmin ), and von Mises stress (σvM ) assessments. Implants were analyzed using the σvM . The higher σmax was observed at: M4T, followed by M6S/L1, M6S/L2, M4S/L2, and M4S/L1 and the higher σvM : M4T/L1, M4T/L2 and M4S/L2, M6S/L2, M4S/L1, and M6S/L1. The presence of distal tilted (all-on-four) and distal short implants (all-on-six) resulted in higher stresses in both situations in the maxillary bone in comparison to the presence of vertical implants (all-on-four). © 2013 Wiley Periodicals, Inc.

  9. Guided implant placement and immediate prosthesis delivery using traditional Brånemark System abutments: a pilot study of 23 patients.

    Science.gov (United States)

    Balshi, Stephen F; Wolfinger, Glenn J; Balshi, Thomas J

    2008-06-01

    The aim of this study is to demonstrate the accuracy and clinical precision of a guided surgery protocol by using traditional Brånemark System abutments in conjunction with a prefabricated all-acrylic provisional prosthesis that is immediately installed after implant placement. All presurgical methods in this treatment follow the standard NobelGuide protocol with the exception of the laboratory phase. Once the master cast is retroengineered from the surgical template, traditional Brånemark System abutments were secured onto the implant replicas (master cast) and an all-acrylic provisional prosthesis was constructed at the abutment level. The typical abutments used with this protocol, adjustable Guided Abutments, were not used. Twenty-three patients were treated in this pilot study. Via the surgical template, all implants were placed to the desired depth as planned in the virtual implant planning program. After the traditional Brånemark Abutments were installed, the provisional prosthesis was delivered and occlusion verified. The prosthesis fit was checked at abutment level clinically and radiographically. This report shows the extreme accuracy of this guided surgery protocol. If each step of this protocol is followed precisely, it is possible to deliver a prefabricated prosthesis built to traditional Brånemark System Abutments, which is extremely favorable for long-term patient and prosthesis management.

  10. Atherosclerosis of coronary blood vessels - local or systemic inflamation?

    Science.gov (United States)

    Pejkov, Hristo; Kedev, Sasko; Panov, Saso; Srbinovska-Kostovska, Elizabeta; Lang, Irene

    2013-01-01

    The presence of atherosclerotic lesions in the blood vessels is a predisposition for the development and occurrence of acute ischaemic attacks. Bigger atherosclerotic lesions in the coronary blood vessels cause lumen occlusion, which is a cause of acute myocardial infarction. Endothelial dysfunction is defined as an ability of the endothelium to produce vasorelaxing nitric oxide (NO), or deregulation of the other vasoactive substances, such as angiotensin II and endothelin [13]. This definition describes endothelial dysfunction as an improper vasomotor constriction of the vessel, that leads to lumen occlusion of the already existing atherosclerotic lesions. According to the modern model, the development of atherosclerotic plaque and inappropriate endothelial NO production have a synergistic role in patho-physiological and molecular processes in the blood vessels [14]. Lesions in the coronary arteries are deposits of huge quantities of foamy cells and fibrous plaques. The thin fibrous plaques are 10-20% of the total plaque population and are the cause of 80-90% of clinical cases due to their ability to rupture [48]. According to all the results from published studies by far, it has been pointed out that the plaque stability, not the absolute size influences the rupture potential. Elucidating the risk factors that may modify in the atherogenesis and the consequent atherothrombic effect is the first step to this goal.

  11. Waves and fluid-solid interaction in stented blood vessels

    Science.gov (United States)

    Frecentese, S.; Argani, L. P.; Movchan, A. B.; Movchan, N. V.; Carta, G.; Wall, M. L.

    2018-01-01

    This paper focuses on the modelling of fluid-structure interaction and wave propagation problems in a stented artery. Reflection of waves in blood vessels is well documented in the literature, but it has always been linked to a strong variation in geometry, such as the branching of vessels. The aim of this work is to detect the possibility of wave reflection in a stented artery due to the repetitive pattern of the stents. The investigation of wave propagation and possible blockages under time-harmonic conditions is complemented with numerical simulations in the transient regime.

  12. Why Are Men Satisfied or Dissatisfied with Penile Implants? A Mixed Method Study on Satisfaction with Penile Prosthesis Implantation.

    Science.gov (United States)

    Carvalheira, Ana; Santana, Rita; Pereira, Nuno M

    2015-12-01

    Studies have demonstrated high levels of satisfaction with penile prosthesis implantation (PPI). However, qualitative research exploring the experience of PPI through men's narratives is scarce. The main goals were to analyze (i) the level of sexual satisfaction (quantitatively), and (ii) the reasons for satisfaction and/or dissatisfaction with PPI (qualitatively). Participants were 47 men with erectile dysfunction who underwent surgery between 2003 and 2012, placed by a single surgeon. Structured telephone interviews were carried out. Satisfaction with PPI was a qualitative and quantitative measure assessed through the following four items: (i) "Would you repeat the PPI surgery?"; (ii) "Would you recommend the PPI surgery?"; (iii) "How satisfied are you with the PP?"; and (iv) "Could you explain the motives of your satisfaction/dissatisfaction?". The majority of men (79%) reported to be satisfied with PPI. Content analysis revealed four main themes for men's satisfaction with the PPI: (i) psychological factors were reported 54 times (n = 54) and included positive emotions, self-esteem, confidence, enhancement of male identity, major live change, and self-image; (ii) improvement of sexual function was reported 54 times (n = 54) and referred to achievement of vaginal penetration, increase of sexual desire, sexual satisfaction, penis size, and improvement of erectile function; (iii) relationship factors were reported 11 times (n = 11) and referred to relationship improvement and the possibility of giving pleasure to the partner; and (iv) improvement in urinary function (n = 3). The level of satisfaction with the implementation of penile prostheses is very high, therefore constituting a treatment for erectile dysfunction with a positive impact on the experience of men at sexual, psychological and relational level. © 2015 International Society for Sexual Medicine.

  13. Use of the frontal process of the maxillary bone for implant placement to retain a nasal prosthesis: a clinical report.

    Science.gov (United States)

    Proussaefs, Periklis

    2004-01-01

    Implant placement to provide support and retention for nasal prostheses has been described in the literature. The anatomic sites that have been utilized for implant placement are the nasal bones, the premaxillary area through the nasal fossae, and the anterior wall of the frontal sinus. In the patient described, after a presurgical computerized tomography scan to determine adequacy of bone volume, 1 conventional threaded hydroxyapatite-coated root-form implant, created for intraoral use, was placed in the frontal process of the maxillary bone and 2 additional conventional implants were placed in the premaxillary area through the nasal fossa. Six months after implant placement, second-stage surgery was completed. A single bar connecting the 3 implants was fabricated. The removable nasal prosthesis was retained on the bar with 2 clips. An examination 1 year postsurgery revealed no clinical signs of pathosis. Long-term clinical follow-up of this case should continue and a sufficient number of additional cases should be investigated before use of the frontal process of the maxillary bone for implant retention can be recommended on a routine basis.

  14. Ten-Year Follow-up of a Blind Patient Chronically Implanted with Epiretinal Prosthesis Argus I.

    Science.gov (United States)

    Yue, Lan; Falabella, Paulo; Christopher, Punita; Wuyyuru, Varalakshmi; Dorn, Jessy; Schor, Paulo; Greenberg, Robert J; Weiland, James D; Humayun, Mark S

    2015-12-01

    The Argus I implant is the first-generation epiretinal prosthesis approved for an investigational clinical trial by the United States Food and Drug Administration. Herein we report testing results obtained from a 10-year follow-up to study the physiologic effects of the bioelectronic visual implant after prolonged chronic electrical stimulation. Case report. One man, 55 years of age when enrolled in the study, underwent surgical implantation of the Argus I in June 2004, followed by periodic tests from July 2004 through June 2014, spanning a total of 10 years. The decade-long follow-up consisted of implant system performance tests, subject visual function evaluation, and implant-retina interface analysis. Changes in electrode impedance and perceptual threshold over the time course; subject's performance on visual function task, orientation, and mobility tests; and optical coherence tomography data, fundus imaging, and fluorescein angiography results for the assessment of subject's implant-retina physical interface. Electrically elicited phosphenes were present 10 years after implantation of an epiretinal stimulator. The test subject not only was able to perceive phosphenes, but also could perform visual tasks at rates well above chance. This decade-long follow-up report provides further support for the use of retinal prostheses as a long-lasting treatment for some types of blindness. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  15. Rehabilitation of Nose following Chemical Burn Using CAD/CAM Made Substructure for Implant Retained Nasal Prosthesis: A Clinical Report

    Directory of Open Access Journals (Sweden)

    Saurabh Chaturvedi

    2017-01-01

    Full Text Available Insufficient knowledge of medical chemicals and their improper use have destructive effects. Accidental exposure to chemicals on facial tissue may result in large facial defect. For ages the tradition of piercing nose is common but improper use of unknown chemical for piercing has deleterious effect. Mostly rhinectomy defects are acquired caused by trauma or malignant diseases. Prosthetic rehabilitation is the preferred treatment of choice for any large rhinectomy defects as medical and surgical interventions are ineffective in developing esthetics. Main concern with the prosthesis for such defects is retention. This article describes rehabilitation of a patient with large size nasal defect created by chemical burn in childhood during piercing. Implant retained customized silicone nasal prosthesis was fabricated using simple O-ring attachments and innovative modified polyamide acrylic resin substructure acting as skeleton.

  16. The Thrust Plate Hip Prosthesis: A Follow-Up of 15-20 Years With 102 Implants.

    Science.gov (United States)

    Kaegi, Maja; Buergi, Martin L; Jacob, Hilaire A C; Bereiter, Heinz H

    2016-05-01

    Between November 1992 and January 1999, a cohort of 102 thrust plate hip prostheses was implanted. We now clinically and radiologically evaluate the remaining 73 prostheses with a mean follow-up of 17.2 years. The Harris Hip Score increased from 51.4 points preoperatively to 94.3 points at the time of this follow-up. No further changes in the radiologic findings occurred since the first follow-up, published in 2005, conducted 2-8 years after implantation. Within 15 to 20 years after primary implantation of the 102 prostheses, 6 aseptic loosenings occurred, which correspond to a cumulated survival rate of 94.7% at 17 and 91.8% at 18 years. Although the thrust plate hip prostheses is no longer marketed, the biomechanical behaviour of this unique, clinically successful prosthesis deserves attention. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. [Aseptic loosening of total ankle replacement : Two-stage revision with bone augmentation of osseous defects and secondary prosthesis implantation].

    Science.gov (United States)

    Barg, A; Wiewiorski, M; Valderrabano, V

    2017-06-01

    To remove loosened ankle prosthesis components, perform osseous defect augmentation, and reimplant definitive prosthesis components to preserve ankle range of motion. Aseptic loosening of the tibial and/or talar ankle prosthesis components with substantial bone defect. General surgical/anesthesiological risks, infections, critical soft tissue conditions, nonmanageable hindfoot instability, neurovascular impairment of the lower extremity, neuroarthropathy, substantial nonreconstructable osseous defects with or without cysts on the tibial and/or talar side, noncompliance, primary total ankle replacement (TAR) using intramedullary fixation (stem fixation), severely reduced bone quality, insulin-dependent diabetes mellitus, smoking, unrealistic patients' expectations, high activity in sports. Exposure of the ankle joint using the previous incision. Mobilization and removal of loosened prosthesis components. Debridement of bone stock. Assessment and measurement of osseous defects. Harvesting of iliac crest autograft. Screw fixation of iliac crest autograft. Placement of polyethylene inlay as a spacer. Wound closure in layers at the ankle and the iliac crest. Implantation of definitive prosthesis components. A soft wound dressing. Thromboprophylaxis recommended. Mobilization on postoperative day 1 using a stabilizing walking boot/cast for 6 weeks (sole contact but no weight bearing). Clinical and radiographic follow-up 3 months postoperatively including computed tomography to assess osseous consolidation. After the second surgery, patient mobilization on postoperative day 1 with 15 kg partial weight bearing using a stabilizing walking boot/cast for 6 weeks. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is initiated gradually. From January 2007 to December 2012, a two-stage revision TAR was performed in 5 patients (46.8 and 71.4 years). The time between the initial TAR and revision was 2.4-11.5 years. No intra

  18. Implantation of AMS 700 LGX penile prosthesis preserves penile length without the need for penile lengthening procedures

    Directory of Open Access Journals (Sweden)

    Carlo Luigi Augusto Negro

    2016-01-01

    Full Text Available Implantation of an inflatable penile prosthesis (IPP is a well-established definitive solution for erectile dysfunction when conservative treatments fail. Penile implants may shorten the penis. The AMS 700 LGX IPP is in common use but reports on its mechanical reliability, medium-term postsurgical patient satisfaction, and mean penile length preservation are lacking. We investigate the mean penile length, mechanical reliability, and patient satisfaction at 6 and 12 months after implantation of the AMS 700 LGX. This prospective study consecutively enrolled men undergoing first-time IPP implant surgery from February 2009 to April 2012. Stretched flaccid penile length, penile length at 50% and 100% of stiffness (P50 and P100 and International Index of Erectile Function (IIEF and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS scores, were measured at 6 and 12 months postsurgery. Of 45 patients who underwent AMS 700 LGX implantation (median age 61 years and completed 6 months′ follow-up, 36 (80% completed the study. A significant difference in stretched flaccid penile length was seen between 6 and 12 months (P = 0.033. P100 was also significantly increased at 6 and 12 months, with a mean 10% increase (1.3 ± 0.4 cm from baseline to 12 months. Differences in mean IIEF scores at 6 and 12 months were significant for the desired domain (P = 0.0001 and for overall satisfaction (P = 0.002; however, mean EDITS scores at 6 and 12 months were not significantly improved. AMS 700 LGX is a powerful tool for preserving penile length in men undergoing penile prosthesis implantation.

  19. Podoplanin immunopositive lymphatic vessels at the implant interface in a rat model of osteoporotic fractures.

    Directory of Open Access Journals (Sweden)

    Katrin Susanne Lips

    Full Text Available Insertion of bone substitution materials accelerates healing of osteoporotic fractures. Biodegradable materials are preferred for application in osteoporotic patients to avoid a second surgery for implant replacement. Degraded implant fragments are often absorbed by macrophages that are removed from the fracture side via passage through veins or lymphatic vessels. We investigated if lymphatic vessels occur in osteoporotic bone defects and whether they are regulated by the use of different materials. To address this issue osteoporosis was induced in rats using the classical method of bilateral ovariectomy and additional calcium and vitamin deficient diet. In addition, wedge-shaped defects of 3, 4, or 5 mm were generated in the distal metaphyseal area of femur via osteotomy. The 4 mm defects were subsequently used for implantation studies where bone substitution materials of calcium phosphate cement, composites of collagen and silica, and iron foams with interconnecting pores were inserted. Different materials were partly additionally functionalized by strontium or bisphosphonate whose positive effects in osteoporosis treatment are well known. The lymphatic vessels were identified by immunohistochemistry using an antibody against podoplanin. Podoplanin immunopositive lymphatic vessels were detected in the granulation tissue filling the fracture gap, surrounding the implant and growing into the iron foam through its interconnected pores. Significant more lymphatic capillaries were counted at the implant interface of composite, strontium and bisphosphonate functionalized iron foam. A significant increase was also observed in the number of lymphatics situated in the pores of strontium coated iron foam. In conclusion, our results indicate the occurrence of lymphatic vessels in osteoporotic bone. Our results show that lymphatic vessels are localized at the implant interface and in the fracture gap where they might be involved in the removal of

  20. The influence of prosthesis design on the outcomes of tooth-implants immediately placed and loaded by means of one-piece titanium restoration.

    Science.gov (United States)

    Toti, Paolo; Marconcini, Simone; Giammarinaro, Enrica; Pedretti, Giorgio; Barone, Antonio; Covani, Ugo

    2017-11-28

    Our purpose was to evaluate the occurrence of complications, and the degree of bone loss in a cohort of patients treated with fixed prostheses supported by immediately loaded dental implants. The primary aim was to compare partial versus full-arch Fixed Dental Prostheses. We then tested the effect of sinus lifting. In the present retrospective cohort study, the patients had their implants restored with Fixed Dental Prostheses supported by dental implants positioned in the posterior maxilla and mandible. When necessary, the maxillary sinuses were grafted with particulate autogenous bone. Patients were then ranked according to the following predictors: length of prosthesis, crown-to-implant ratio, number of crowns to number of implants ratio, and presence of sinus lifting. Outcomes were evaluated for up to 2 years' survey regarding the peri-implant marginal bone loss and implant/prosthesis survival rates. Fifty-eight subjects (209 implants) were rehabilitated with 25 fixed full-arch prostheses and 33 partial fixed dental implant bridges (16 supported by implants placed in grafted sinus). The mean marginal bone loss for implants supporting partial Fixed Dental Prostheses amounted to 0.81mm, whereas that for implants within the group of full-arch Fixed Dental Prostheses was of 1.21mm; the comparison of the levels in the two groups showed a significant difference (P=0.0055). A statistically-significant difference (P=0.0006) was found between the bone loss around maxillary implants (1.53mm) and the bone loss around mandibular implants (1.10mm). Two implants and four prostheses failed; two-year survival rates of partial and of full-arch Fixed Dental Prostheses, respectively, resulted as 94.1% and 96%. Bone loss in full-arch prostheses appeared to be higher than in that of partial prosthesis. Implant-supported prostheses in the maxillae exhibited a bone loss higher than that registered in mandibles.

  1. Blood vessel modeling for interactive simulation of interventional neuroradiology procedures.

    Science.gov (United States)

    Kerrien, E; Yureidini, A; Dequidt, J; Duriez, C; Anxionnat, R; Cotin, S

    2017-01-01

    Endovascular interventions can benefit from interactive simulation in their training phase but also during pre-operative and intra-operative phases if simulation scenarios are based on patient data. A key feature in this context is the ability to extract, from patient images, models of blood vessels that impede neither the realism nor the performance of simulation. This paper addresses both the segmentation and reconstruction of the vasculature from 3D Rotational Angiography data, and adapted to simulation: An original tracking algorithm is proposed to segment the vessel tree while filtering points extracted at the vessel surface in the vicinity of each point on the centerline; then an automatic procedure is described to reconstruct each local unstructured point set as a skeleton-based implicit surface (blobby model). The output of successively applying both algorithms is a new model of vasculature as a tree of local implicit models. The segmentation algorithm is compared with Multiple Hypothesis Testing (MHT) algorithm (Friman et al., 2010) on patient data, showing its greater ability to track blood vessels. The reconstruction algorithm is evaluated on both synthetic and patient data and demonstrate its ability to fit points with a subvoxel precision. Various tests are also reported where our model is used to simulate catheter navigation in interventional neuroradiology. An excellent realism, and much lower computational costs are reported when compared to triangular mesh surface models. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Hemodynamic and clinical impact of prosthesis-patient mismatch after transcatheter aortic valve implantation.

    Science.gov (United States)

    Ewe, See Hooi; Muratori, Manuela; Delgado, Victoria; Pepi, Mauro; Tamborini, Gloria; Fusini, Laura; Klautz, Robert J M; Gripari, Paola; Bax, Jeroen J; Fusari, Melissa; Schalij, Martin J; Marsan, Nina Ajmone

    2011-10-25

    This study examined the mid-term hemodynamic and clinical impact of prosthesis-patient mismatch (PPM) in patients undergoing transcatheter aortic valve implantation (TAVI) with balloon-expandable valves. PPM can be observed after aortic valve surgery. However, little is known about the incidence of PPM in patients undergoing TAVI. Echocardiography and clinical assessment were performed in 165 patients at baseline, before hospital discharge, and at 6 months after TAVI. PPM was defined as an indexed effective orifice area ≤0.85 cm(2)/m(2). Thirty patients (18.2%) showed PPM before hospital discharge. At baseline, patients with PPM had a larger body surface area (1.84 ± 0.18 m(2) vs. 1.73 ± 0.18 m(2), p = 0.003) and a greater severity of aortic stenosis (indexed valve area 0.35 ± 0.09 cm(2)/m(2) vs. 0.40 ± 0.10 cm(2)/m(2), p = 0.005) than patients without PPM. Patients with PPM demonstrated a slower and smaller reduction in mean transaortic gradient, limited left ventricular (LV) mass regression, and left atrial volume reduction over 6 months compared with patients without PPM. LV filling pressure, measured by E/e', tended to remain elevated in patients with PPM. Importantly, a higher proportion of patients with PPM did not improve in New York Heart Association functional class compared with patients without PPM (36.7% vs. 1.5%, p < 0.001), although major adverse valve-related and cardiovascular events did not differ between the 2 groups. PPM may be observed after TAVI and when present may be accompanied by less favorable changes in transvalvular hemodynamics, limited LV mass regression, persistent elevated LV filling pressure, and less improvement in clinical functional status. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  3. Prosthesis-patient mismatch after transcatheter aortic valve implantation with the Medtronic-Corevalve bioprosthesis.

    Science.gov (United States)

    Jilaihawi, Hasan; Chin, Derek; Spyt, Tomasz; Jeilan, Mohamed; Vasa-Nicotera, Mariuca; Bence, Johan; Logtens, Elaine; Kovac, Jan

    2010-04-01

    Prosthesis-patient mismatch (P-PM) is an important determinant of morbidity and mortality following open aortic valve replacement. The aims of this study were to report its incidence and determinants following transcatheter aortic valve implantation (TAVI) with the Corevalve bioprosthesis, which have-thus far-not been described. Patients with severe calcific aortic stenosis received TAVI with the Corevalve bioprosthesis via transfemoral route. Following TAVI, moderate P-PM was defined as indexed aortic valve effective orifice area (AVAi) Clinical, echocardiographic, and procedural factors relating to P-PM were studied. Optimal device position was defined on fluoroscopy as final position of the proximal aspect of the Corevalve stent frame 5-10 mm below the native aortic annulus. Between January 2007 and January 2009, 50 consecutive patients underwent TAVI in a single centre with the Corevalve bioprosthesis. Mean age was 82.8 years (SD 5.9; 70-93) and 48% were male. P-PM occurred in 16 of 50 cases (32%). Optimal position was achieved in 50% of cases. P-PM was unrelated to age, annulus size, LVOT size, Corevalve size, aortic angulation, ejection fraction, and sex. It was inversely correlated to optimal position (Spearman rho r = -0.34, P = 0.015). Those with optimal positioning had a 16% incidence of P-PM relative to 48% of those with suboptimal positioning (Pearson chi(2) P = 0.015). The incidence of P-PM following TAVI with the Corevalve bioprosthesis is compared favourably with that seen after AVR with conventional open stented bioprostheses and its occurrence is influenced by device positioning.

  4. A Novel Technique of Fabricating a Modified Removable Provisional Prosthesis over an Autologous Bone Grafted Maxillary Anterior Edentulous Segment Prior to Implant Placement

    OpenAIRE

    Andonissamy, Leoney; Vidhya, N. Sri

    2017-01-01

    Implant dentistry has provided a lot of surgical as well as prosthetic techniques for improving the success of the implants. The surgical technique commonly followed now prior to implant placement is bone grafting procedure. One of the commonest techniques is the use of autologous block graft harvested from mandibular chin region. However, interference in healing as well as excessive bone resorption due to the use of removable provisional prosthesis over the bone grafted region has been commo...

  5. Migraine aura pathophysiology: the role of blood vessels and microembolisation

    OpenAIRE

    Dalkara, Turgay; Nozari, Ala; Moskowitz, Michael A

    2010-01-01

    Migraine attacks with auras are sometimes associated with underlying hereditary or acquired cerebrovascular disorders. A unifying pathophysiological explanation linking migraine to these conditions has been diffcult to identify. On the basis of genetic and epidemiological evidence, we suggest that changes in blood vessels, hypoperfusion disorders, and microembolisation can cause neurovascular dysfunction and evoke cortical spreading depression, an event that is widely thought to underlie aura...

  6. Acrolein generation stimulates hypercontraction in isolated human blood vessels

    OpenAIRE

    Conklin, D.J.; Bhatnagar, A.; Cowley, H.R.; Johnson, G.H.; Wiechmann, R.J.; Sayre, L.M.; Trent, M.B.; Boor, P.J.

    2006-01-01

    Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension—all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontra...

  7. Historical Perspective and Future Direction of Blood Vessel Developments.

    Science.gov (United States)

    Dimitrievska, Sashka; Niklason, Laura E

    2018-02-01

    Over the past 40 years, remarkable advances have been made in our understanding of successful blood vessel regeneration, starting with the failures of early tissue-engineered vascular grafts designed using isolated components or molecules, such as collagen gels. The vascular tissue engineers are today better educated and have steered ongoing research developments toward clinical developments of more complete vascular grafts that replicate the multitude of specialized arterial aspects required for function. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

  8. DLC coating of textile blood vessels using PLD

    Czech Academy of Sciences Publication Activity Database

    Kocourek, Tomáš; Jelínek, Miroslav; Vorlíček, Vladimír; Zemek, Josef; Janča, T.; Žížková, V.; Podlaha, J.; Popov, C.

    2008-01-01

    Roč. 93, č. 3 (2008), s. 627-632 ISSN 0947-8396 R&D Projects: GA MPO FI-IM2/068; GA ČR GA202/06/0216 Institutional research plan: CEZ:AV0Z10100522 Keywords : blood vessels * PLD * DLC * sp2 * sp3 Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.884, year: 2008

  9. Stress Analysis on Single Cobalt/Chrome Prosthesis With a 15-mm Cantilever Placed Over 10/13/15-mm-length Implants: A Simulated Photoelastic Model Study.

    Science.gov (United States)

    Gastaldo, José Fábio Guastelli; Pimentel, Angélica Castro; Gomes, Maria Helena; Sendyk, Wilson Roberto; Laganá, Dalva Cruz

    2015-12-01

    The aim of study was to assess the stress around 10/13/15-mm implants in the mandibular area with a 15-mm cantilevered acrylic-resin-coated prostheses following the application force, using the photoelasticity method. Three photoelastic mandibular models were created containing 10-, 13-, and 15-mm implants in length and 3.75 mm in diameter. The implants had bore internal hex connections and were placed parallel to the intermental region. Abutments with 1-mm high cuffs were placed over the implants, and a single cobalt/chrome metallic prosthesis with a 15-mm cantilever, coated with thermoplastic acrylic resin, was placed on top. Loads of 1.0 and 3.0 bars were applied, and the images were photographed and assessed by photoelasticity method. The greatest stress levels were observed for the 10-mm implants. The stress pattern was the same regardless of implant length; only the magnitude of the stress along the implant body revealed changes. Increased implant length played a role in reducing stress on the investigated area of the model, and the 15-mm implants exhibited the best performance in regard to stress distribution. The highest stress levels were found in the implants closest to the cantilever and the central implant. The longest implants were more favorable in regard to the stress distribution on the peri-implant support structures in the 15-mm cantilevered prosthesis under loads.

  10. Extraocular surgery for implantation of an active subretinal visual prosthesis with external connections: feasibility and outcome in seven patients.

    Science.gov (United States)

    Besch, D; Sachs, H; Szurman, P; Gülicher, D; Wilke, R; Reinert, S; Zrenner, E; Bartz-Schmidt, K U; Gekeler, F

    2008-10-01

    Due to low energy levels in microphotodiode-based subretinal visual prostheses, an external power supply is mandatory. We report on the surgical feasibility and the functional outcome of the extraocular part of an approach to connect a subretinal prosthesis to an extracorporeal connector in the retro-auricular space via a trans-scleral, transchoroidal cable. Seven volunteers with retinitis pigmentosa received an active subretinal implant; energy was supplied by gold wires on a trans-sclerally, transchoroidally implanted polyimide foil leading to the lateral orbital rim where it was fixated and connected to a silicone cable. The cable was implanted subperiostally beneath the temporal muscle using a trocar to the retro-auricular space where it penetrated the skin for connection to a stimulator. To avoid subretinal movement of the implant, three tension relief points have been introduced. All implantations were performed as planned without complications, and no serious adverse events occurred in the postoperative period. Fixation of the implants was stable throughout the entire study duration of 4 weeks; permanent skin penetration proved to be uncomplicated. Motility was minimally restricted in downgaze and ab-/adduction. Explantation was uneventful. The above-described procedure provides a method for stable fixation of a subretinal device with a trans-scleral, transchoroidal cable connection to an extracorporeal connector.

  11. Implantation of transcatheter aortic valve prosthesis through the ascending aorta concomitant with coronary artery bypass grafting without cardiopulmonary bypass

    Science.gov (United States)

    Leal, João Carlos Ferreira; Avanci, Luis Ernesto; Abelaira Filho, Achilles; Almeida, Thiago Faria; Braile, Domingo Marcolino

    2014-01-01

    Introdution The transcatheter aortic valve implantation in the treatment of high-risk symptomatic aortic stenosis has increased the number of implants every year. The learning curve for transcatheter aortic valve implantation has improved since the last 12 years, allowing access alternatives. Objective The aim of this study is to approach the implantation of transcatheter aortic valve through transaortic via associated with off-pump cardiopulmonary bypass surgery in a 67-year-old man, with chronic obstructive pulmonary disease, arterial hypertension and kidney transplant. Methods Off-pump coronary artery bypass surgery was performed and the valve in the aortic position was released successfully. Results There were no complications in the intraoperative and postoperative period. Gradient reduction, effective orifice increasing of the prosthesis and absence of valvular regurgitation after implantation were observed by transesophageal echocardiography. Conclusion Procedural success demonstrates that implantation of transcatheter aortic valve through the ascending aorta associated with coronary artery bypass surgery without CPB is a new option for these patients. PMID:25714221

  12. Clinical and radiological results after implantation of the femoral neck preserving Delfi M hip prosthesis: a case series.

    Science.gov (United States)

    Budde, Stefan; Windhagen, Henning; Lerch, Matthias; Broese, Maximilian; Götze, Patricc; Thorey, Fritz

    2012-01-01

    Various types of bone preserving total hip prostheses with a proximal force transmission concept have been developed for younger adults, one of these being the implant "Delfi M®", produced by ESKA until 2009. Since the demand could not meet the expectations, the production was stopped due to economic reasons so that only 31 implants of this type were sold and even less actually implanted. This study followed up 15 Delfi M® prostheses in 12 patients for 3.1 years and represents the only existing valid data about this implant.Demographical, preoperative and postoperative data including clinical scores (HOOS and mHHS) were collected retrospectively. Postoperative X-rays were analyzed by an independent radiologist. One implant had to be exchanged due to an infection and another one due to excessive implant migration. The mHHS and the HOOS scores showed a significant improvement after surgery. In the radiological analysis, there were no signs of radiolucent lines or osteolyses.This trial demonstrates good clinical and radiological midterm results for the Delfi M prosthesis. Limitations of this study are a small sample size and a follow-up time of 3 years at only one timepoint. © 2012 – IOS Press and the authors. All rights reserved

  13. Leptospirosis-associated disturbances of blood vessels, lungs and hemostasis.

    Science.gov (United States)

    Medeiros, Fernanda da Rocha; Spichler, Anne; Athanazio, Daniel A

    2010-01-01

    The frequency of massive pulmonary hemorrhages seems to be increasing in different geographic areas; however, there is no clear explanation for this trend. Although data on the pathogenesis of such complications are scarce, recent research indicates a potential role of autoimmunity and/or multifactorial mechanisms. However, much information is already available on the disturbance of hemostasis and blood vessels in leptospirosis-related literature, even if some contradictory concepts coexist. The purpose of this review is to integrate both new and classical information from human and animal studies on severe pulmonary forms of leptospirosis and disorders of hemostasis and blood vessels. We propose that the involvement of blood vessels in leptospirosis must be understood as a sepsis-like, diffuse process of endothelial activation/damage rather than as a classical systemic vasculitis. Pulmonary hemorrhages are most likely multifactorial and there has recently been evidence against the role of autoimmunity; however, further investigation of strain variations, exposure to hydrocarbons and association with renal dysfunction is required. Thrombocytopenia is a consistent feature of leptospirosis but it is not clear whether it is attributable to sepsis-related mechanisms. In addition, further investigation is required to define whether platelet function is activated or inhibited during severe leptospirosis. 2010 Elsevier B.V. All rights reserved.

  14. Utilizing the Foreign Body Response to Grow Tissue Engineered Blood Vessels in Vivo.

    Science.gov (United States)

    Geelhoed, Wouter J; Moroni, Lorenzo; Rotmans, Joris I

    2017-04-01

    It is well known that the number of patients requiring a vascular grafts for use as vessel replacement in cardiovascular diseases, or as vascular access site for hemodialysis is ever increasing. The development of tissue engineered blood vessels (TEBV's) is a promising method to meet this increasing demand vascular grafts, without having to rely on poorly performing synthetic options such as polytetrafluoroethylene (PTFE) or Dacron. The generation of in vivo TEBV's involves utilizing the host reaction to an implanted biomaterial for the generation of completely autologous tissues. Essentially this approach to the development of TEBV's makes use of the foreign body response to biomaterials for the construction of the entire vascular replacement tissue within the patient's own body. In this review we will discuss the method of developing in vivo TEBV's, and debate the approaches of several research groups that have implemented this method.

  15. Biomechanical evaluation of implant-supported prosthesis with various tilting implant angles and bone types in atrophic maxilla: A finite element study.

    Science.gov (United States)

    Gümrükçü, Zeynep; Korkmaz, Yavuz Tolga; Korkmaz, Fatih Mehmet

    2017-07-01

    The purpose of this study is to evaluate and compare bone stress that occurs as a result of using vertical implants with simultaneous sinus augmentation with bone stress generated from oblique implants without sinus augmentation in atrophic maxilla. Six, three-dimensional (3D) finite element (FE) models of atrophic maxilla were generated with SolidWorks software. The maxilla models were varied for two different bone types. Models 2a, 2b and 2c represent maxilla models with D2 bone type. Models 3a, 3b and 3c represent maxilla models with D3 bone type. Five implants were embedded in each model with different configurations for vertical implant insertion with sinus augmentation: Model 2a/Model 3a, 30° tilted insertion; Model 2b/Model 3b and 45° tilted insertion; Model 2c/Model 3c. A 150 N load was applied obliquely on the hybrid prosthesis. The maximum von Mises stress values were comparatively evaluated using color scales. The von Mises stress values predicted by the FE models were higher for all D3 bone models in both cortical and cancellous bone. For the vertical implant models, lower stress values were found in cortical bone. Tilting of the distal implants by 30° increased the stress in the cortical layer compared to vertical implant models. Tilting of the distal implant by 45° decreased the stress in the cortical bone compared to the 30° models, but higher stress values were detected in the 45° models compared to the vertical implant models. Augmentation should be the first treatment option in atrophic maxilla in terms of biomechanics. Tilted posterior implants can create higher stress values than vertical posterior implants. During tilting implant planning, the use of a 45° tilted implant results in better biomechanical performance in peri-implant bone than 30° tilted implant due to the decrease in cantilever length. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Tackling the Issue of High Postoperative Pacemaker Implantation Rates in Sutureless Aortic Valve Replacement: Should Balloon Inflation be Removed from the Implantation Method of the Perceval Prosthesis?

    Science.gov (United States)

    Charles Blouin, Mathieu; Bouhout, Ismail; Demers, Philippe; Carrier, Michel; Perrault, Louis; Lamarche, Yoan; El-Hamamsy, Ismail; Bouchard, Denis

    2017-05-01

    Sutureless aortic valve replacement (AVR) is an emerging alternative to standard AVR in elderly and high-risk patients. This procedure is associated with a high rate of postoperative permanent pacemaker implantation (PPI). The study aim was to assess the impact on the rate of PPI of implanting the Perceval prosthesis without using balloon inflation. A total of 159 patients who underwent sutureless AVR using the Perceval prosthesis was included. Balloon inflation was used in 132 patients (Balloon group) and not used in the remaining 27 (No-Balloon group). Clinical, echocardiographic and electrocardiographic outcomes were assessed. There was no significant difference in PPI rate between the two groups (26% for Balloon group versus 22% in No-Balloon group; p = 0.700). Balloon inflation had no significant impact on the incidence of paravalvular leaks (p = 0.839), or on the need to return to cardiopulmonary bypass (CPB) intraoperatively due to paravalvular leak or unsatisfactory deployment (p >0.999). Mean and peak transaortic pressure gradients were similar between the two groups (p = 0.417 and p = 0.522, respectively). Cross-clamp and CPB times were shorter in the No-Balloon group (49.6 ± 15.9 min versus 61.1 ± 25.6 min and 64.1 ± 26.3 min versus 79.6 ± 35.4 min, respectively; p = 0.027 and p = 0.012, respectively). The two groups had similar postoperative PPI rates. Implanting the Perceval prosthesis without balloon inflation is safe and had no impact on paravalvular leaks, intraoperative complications or hemodynamic results. Reductions in aortic cross-clamp time and CPB time were observed when the balloon was not used.

  17. Blood vessel classification into arteries and veins in retinal images

    Science.gov (United States)

    Kondermann, Claudia; Kondermann, Daniel; Yan, Michelle

    2007-03-01

    The prevalence of diabetes is expected to increase dramatically in coming years; already today it accounts for a major proportion of the health care budget in many countries. Diabetic Retinopathy (DR), a micro vascular complication very often seen in diabetes patients, is the most common cause of visual loss in working age population of developed countries today. Since the possibility of slowing or even stopping the progress of this disease depends on the early detection of DR, an automatic analysis of fundus images would be of great help to the ophthalmologist due to the small size of the symptoms and the large number of patients. An important symptom for DR are abnormally wide veins leading to an unusually low ratio of the average diameter of arteries to veins (AVR). There are also other diseases like high blood pressure or diseases of the pancreas with one symptom being an abnormal AVR value. To determine it, a classification of vessels as arteries or veins is indispensable. As to our knowledge despite the importance there have only been two approaches to vessel classification yet. Therefore we propose an improved method. We compare two feature extraction methods and two classification methods based on support vector machines and neural networks. Given a hand-segmentation of vessels our approach achieves 95.32% correctly classified vessel pixels. This value decreases by 10% on average, if the result of a segmentation algorithm is used as basis for the classification.

  18. Improvement of retinal blood vessel detection by spur removal and Gaussian matched filtering compensation

    Science.gov (United States)

    Xiao, Di; Vignarajan, Janardhan; An, Dong; Tay-Kearney, Mei-Ling; Kanagasingam, Yogi

    2016-03-01

    Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. In this paper, we proposed approaches for improving the quality of blood vessel detection based on our initial blood vessel detection methods. A blood vessel spur pruning method has been developed for removing the blood vessel spurs both on vessel medial lines and binary vessel masks, which are caused by artifacts and side-effect of Gaussian matched vessel enhancement. A Gaussian matched filtering compensation method has been developed for removing incorrect vessel branches in the areas of low illumination. The proposed approaches were applied and tested on the color fundus images from one publicly available database and our diabetic retinopathy screening dataset. A preliminary result has demonstrated the robustness and good performance of the proposed approaches and their potential application for improving retinal blood vessel detection.

  19. Transcatheter aortic valve implantation in patients with a mitral prosthesis; single center experience and review of literature.

    Science.gov (United States)

    Asil, Serkan; Şahiner, Levent; Özer, Necla; Kaya, E Barış; Evranos, Banu; Canpolat, Uğur; Yorgun, Hikmet; Karagöz, Heves; Aytemir, Kudret

    2016-10-15

    Following the encouraging results of several registries and trials, transcatheter aortic valve implantation (TAVI) has been recognized as a valid option in patients with severe aortic stenosis deemed at high or prohibitive risk for surgical treatment. Good procedural success and good clinical outcomes have been showed and very limited data exist on TAVI in the setting of a preexisting mitral prosthesis regarding the technique, potential complications, and outcomes. Here, we report six cases of transfemoral TAVI with a self-expanding bioprosthesis (CoreValve; Medtronic, Inc) in patients who had previously undergone mitral valve replacement. Preprocedural, intraprocedural ve postprocedural outcome and data were analyzed and a brief literature review is also presented. Our experiences show that transfemoral CoreValve implantation can be performed successfully in patients with mechanical and bioprosthetic mitral valves. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. [Association between allergy to benzoyl peroxide, vitiligo and implantation of a cemented total knee joint prosthesis: Is there a connection?].

    Science.gov (United States)

    Gothner, M; Ozokyay, L; Godau, P; Kälicke, T; Muhr, G; Schildhauer, T A; Dudda, M

    2011-09-01

    Allergies against bone cement or bone cement components have been well-described. We report on a 63-year-old patient who presented with progressive vitiligo all over the body after implantation of a cemented total knee replacement. A dermatological examination was performed and an allergy to benzoyl peroxide was found. A low-grade infection was diagnosed 5 months after implantation of the total knee replacement and the prosthesis was replaced with a cement spacer. After treating the infection of the knee replacement non-cemented arthrodesis of the knee was performed. In cases of new, unknown skin efflorescence, urticaria and periprosthetic loosening of cemented joint replacement, the differential diagnosis should include not only infections but also possible allergies against bone-cement and components such as benzoyl peroxide or metal components.

  1. [Modified mini-Hardinge access for hip prosthesis implantation in the supine position].

    Science.gov (United States)

    Mazoochian, F; Schmidutz, F; Fottner, A; Jansson, V

    2014-04-01

    significantly shorter incision length (8.9 vs. 14.0 cm) and a slightly lower blood loss (502 vs. 660 ml) were observed for the modified mini-Hardinge. Moreover, the mini-incision group showed slightly better functional results in the early course. A higher rate of implant malpositioning or a higher peri- and postoperative complication rate was not observed.

  2. Patient-prosthesis mismatch after transapical aortic valve implantation: incidence and impact on survival.

    Science.gov (United States)

    Kukucka, Marian; Pasic, Miralem; Dreysse, Stephan; Mladenow, Alexander; Habazettl, Helmut; Hetzer, Roland; Unbehaun, Axel

    2013-02-01

    Transcatheter aortic valve implantation (TAVI) has become an important therapeutic option for high-risk patients with severe aortic valve stenosis. Patient-prosthesis mismatch (P-PM) is an important determinant of morbidity and mortality after open aortic valve replacement. The objective of our study was to evaluate P-PM incidence and its impact on survival in a large cohort of patients treated with TAVI. We retrospectively analyzed transesophageal echocardiographic data of 278 consecutive patients (Society of Thoracic Surgeons score 18.5 ± 15.3, age 80 ± 8 years) who underwent transapical TAVI with Edwards Sapien valves between April 2008 and March 2011. Effective orifice area was calculated using the continuity equation and indexed with body surface area (iEOA). P-PM was stratified as severe (iEOA < 0.65 cm(2)/cm(2)) and moderate (iEOA, 0.65-0.85 cm(2)/m(2)). Midterm survival (up to 30 months) was analyzed by Kaplan-Meier curves and log-rank tests. There was no P-PM in 181 (65.1%) patients; moderate P-PM was found in 76 (27.3%) patients and severe P-PM in 21 (7.6%). Thirty-day survival was 96.0%, 97.3%, and 90.5%. The 3-month survival was 91%, 90%, and 66%, respectively (P = .0013). Combination of severe P-PM with peak pressure gradients greater than 10 mm Hg further reduced the 3-month survival to 48%. Additionally, mean survival time in patients with an ejection fraction less than 50% was significantly shorter than in patients with an ejection fraction greater than 50% (20.8 ± 1.5 vs 24.1 ± 0.8 months; P = .027). P-PM is found in patients undergoing transapical TAVI. Severe mismatch is accompanied by high early mortality, especially when combined with increased pressure gradients. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  3. [Implantation of bipolar prosthesis for treatment of medial femoral neck fractures in the elderly--clinical and radiographic outcome].

    Science.gov (United States)

    Müller, C A; Bayer, J; Szarzynski, E; Südkamp, N P

    2008-12-01

    In our study, we retrospectively evaluated 203 patients with medial or lateral femoral neck fractures who received 210 bipolar prosthesis (7 bilateral implantations) at our institution. 204 patients underwent cemented bipolar hemiarthroplasty. These included 149 females and 54 males with a median age of 82 (46-97) years. At the time of surgery 144 patients (71%) suffered from more than 3 medical conditions. We conducted our follow-up examination at a median of 27.9 months after the operation, at which time 97 patients (48%) had already died. On examination, 17% of our 76 patients had a Harris hip score between 90 and 100 and 20% between 80 and 89 or 70 and 79, respectively. 43% had a score of less than 70. In 20 patients (57%) we found radiographic evidence of periarticular ossification. Signs of loosening according to Gruen were found in 7 out of 35 patients, with no apparent clinical correlation. Surgery-related complications were noted in 15% of our 203 patients--mostly, with 10 cases each, wound infections and postoperative haematomas. In 3 cases of deep wound infection, a removal of the prosthesis was necessary, leading to a Girdlestone hip in one case. Postoperative hip dislocations occurred in 3.4% and intraoperative femur fissures were encountered in 1% of our patients. There were no cases of nerve damage or protrusion of the acetabulum reported. 43% of our patients developed a general complication--mainly cardiological or vascular problems, nephrological or urinary tract diseases, pulmonary or neurological complications. Hip arthroplasty is predominantly applied in older patients, most of them suffering from at least one medical condition at the time of surgery that influences their hospital course. This is why especially the overall physical condition of elderly patients has to be taken seriously into account when planning surgical treatment of femoral neck fractures. In our retrospective study, we have shown that implantation of a bipolar hip prosthesis

  4. Transition from failing dentition to full-arch fixed implant-supported prosthesis with a staged approach using removable partial dentures: a case series.

    Science.gov (United States)

    Cortes, Arthur Rodriguez Gonzalez; Cortes, Djalma Nogueira; No-Cortes, Juliana; Arita, Emiko Saito

    2014-06-01

    The present retrospective case series is aimed at evaluating a staged approach using a removable partial denture (RPD) as an interim prosthesis in treatment to correct a failing dentition until such time as a full-arch fixed implant-supported prosthesis may be inserted. Eight patients, who had undergone maxillary full-arch rehabilitation with dental implants due to poor prognosis of their dentitions, were analyzed. All treatment included initial periodontal therapy and a strategic order of extraction of hopeless teeth. An RPD supported by selected teeth rehabilitated the compromised arch during implant osseointegration. These remaining teeth were extracted prior to definitive prosthesis delivery. Advantages and drawbacks of this technique were also recorded for the cases presented. Among the advantages provided by the staged approach are simplicity of fabrication, low cost, and ease of insertion. Additionally, RPD tooth support prevented contact between the interim prosthesis and healing abutments, promoting implant osseointegration. The main drawbacks were interference with speech and limited esthetic results. Implant survival rate was 100% within a follow-up of at least 1 year. The use of RPDs as interim prostheses allowed for the accomplishment of the analyzed rehabilitation treatments. It is a simple treatment alternative for patients with a low smile line. © 2013 by the American College of Prosthodontists.

  5. Penile prosthesis implantation and tunica albuginea incision without grafting in the treatment of Peyronie's disease with erectile dysfunction

    Science.gov (United States)

    Djordjevic, Miroslav L; Kojovic, Vladimir

    2013-01-01

    We evaluated penile prosthesis implantation with tunica albuginea-relaxing incisions without grafting in the treatment of Peyronie's disease associated with erectile dysfunction. Between April 2005 and June 2011, 62 patients underwent surgery due to severe Peyronie's disease associated with erectile dysfunction. Malleable and inflatable penile prostheses were inserted in 49 and 13 cases, respectively. Penile prostheses were inserted into the corpora cavernosa using the standard ventral approach. After lifting the neurovascular bundle, the tunica albuginea was incised and opened at the plaque region to correct the deformities and to lengthen the penis. Subsequently, the wide neurovascular bundle was replaced, and all incisions of the tunica albuginea were covered to prevent corporal grafting. In the median follow-up of 35 months (range 14–82 months), the penis was completely straightened in 59 (95%) patients. Numbness of the glans, which the patients found initially upsetting, decreased or disappeared spontaneously 3–6 months later. Penile prosthesis implantation with tunica albuginea incisions is a viable alternative in the treatment of Peyronie's disease because the extensive dissection of the neurovascular bundle allows a good approach to the plaque and provides excellent covering of the incised tunica albuginea without additional grafting. PMID:23435473

  6. Angiogenesis and blood vessel stability in inflammatory arthritis.

    LENUS (Irish Health Repository)

    Kennedy, Aisling

    2012-02-01

    OBJECTIVE: To assess blood vessel stability in inflammatory synovial tissue (ST) and to examine neural cell adhesion molecule (NCAM), oxidative DNA damage, and hypoxia in vivo. METHODS: Macroscopic vascularity and ST oxygen levels were determined in vivo in patients with inflammatory arthritis who were undergoing arthroscopy. Vessel maturity\\/stability was quantified in matched ST samples by dual immunofluorescence staining for factor VIII (FVIII)\\/alpha-smooth muscle actin (alpha-SMA). NCAM and 8-oxo-7,8-dihydro-2\\'-deoxyguanosine (8-oxodG) were examined by immunohistochemistry. Angiogenesis was assessed in vitro, using human dermal endothelial cells (HDECs) in a Matrigel tube formation assay. RESULTS: A significant number of immature vessels (showing no pericyte recruitment) was observed in tissue from patients with inflammatory arthritis (P < 0.001), in contrast to osteoarthritic and normal tissue, which showed complete recruitment of pericytes. Low in vivo PO(2) levels in the inflamed joint (median [range] 22.8 [3.2-54.1] mm Hg) were inversely related to increased macroscopic vascularity (P < 0.04) and increased microscopic expression of FVIII and alpha-SMA (P < 0.04 and P < 0.03, respectively). A significant proportion of vessels showed focal expression of NCAM and strong nuclear 8-oxodG expression, implicating a loss of EC-pericyte contact and increased DNA damage, levels of which were inversely associated with low in vivo PO(2) (P = 0.04 for each comparison). Circulating cells were completely negative for 8-oxodG. Exposure of HDEC to 3% O(2) (reflecting mean ST in vivo measurements) significantly increased EC tube formation (P < 0.05). CONCLUSION: Our findings indicate the presence of unstable vessels in inflamed joints associated with hypoxia, incomplete EC-pericyte interactions, and increased DNA damage. These changes may further contribute to persistent hypoxia in the inflamed joint to further drive this unstable microenvironment.

  7. Accuracy and complications of computer-designed selective laser sintering surgical guides for flapless dental implant placement and immediate definitive prosthesis installation.

    Science.gov (United States)

    Di Giacomo, Giovanni A; da Silva, Jorge V; da Silva, Airton M; Paschoal, Gustavo H; Cury, Patricia R; Szarf, Gilberto

    2012-04-01

    Computer-aided dental implant placement seems to be useful for placing implants by using a flapless approach. However, evidence supporting such applications is scarce. The aim of this study is to evaluate the accuracy of and complications that arise from the use of selective laser sintering surgical guides for flapless dental implant placement and immediate definitive prosthesis installation. Sixty implants and 12 prostheses were installed in 12 patients (four males and eight females; age range: 41 to 71 years). Lateral (coronal and apical) and angular deviations between virtually planned and placed implants were measured. The patients were followed up for 30 months, and surgical and prosthetic complications were documented. The mean ± SD angular, coronal, and apical deviations were 6.53° ± 4.31°, 1.35 ± 0.65 mm, and 1.79 ± 1.01 mm, respectively. Coronal and apical deviations of prosthesis, and prosthesis fracture. The cumulative survival rates for implants and prostheses were 98.33% and 91.66%, respectively. The mean lateral deviation was 2 mm. The complication rate was 34.4%. Hence, computer-aided dental implant surgery still requires improvement and should be considered as in the developmental stage.

  8. A time-saving method for transferring occlusal vertical dimension and centric relation of complete denture to a full arch implant prosthesis.

    Science.gov (United States)

    Parnia, Fereidoun; Moslehifard, Elnaz; Motayagheni, Negar; Pournasrollah, Alireza

    2014-09-01

    This clinical report describes a time-saving recording procedure for implant prosthesis. In implant prosthodontics, a few procedures have been suggested to record jaw relationships. Record bases with occlusion rims supported by healing abutments, or screw retained bases are the conventional methods used for mounting definitive implant casts in the articulator. The method described in this article reduces the chair time and is comfortable for both the patient and clinician. In this article, a chair side technique is presented for articulating the definitive implant casts that maintains the established OVD and CR of the patient's existing complete dentures.

  9. CT-angiography-based evaluation of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI-predictive value and optimal thresholds for major anatomic parameters.

    Directory of Open Access Journals (Sweden)

    Florian Schwarz

    Full Text Available BACKGROUND/OBJECTIVES: To evaluate the predictive value of CT-derived measurements of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI and to calculate optimal cutoff values for the selection of various prosthesis sizes. METHODS: The local IRB waived approval for this single-center retrospective analysis. Of 441 consecutive TAVI-patients, 90 were excluded (death within 30 days: 13; more than mild aortic regurgitation: 10; other reasons: 67. In the remaining 351 patients, the CoreValve (Medtronic and the Edwards Sapien XT valve (Edwards Lifesciences were implanted in 235 and 116 patients. Optimal prosthesis size was determined during TAVI by inflation of a balloon catheter at the aortic annulus. All patients had undergone CT-angiography of the heart or body trunk prior to TAVI. Using these datasets, the diameter of the long and short axis as well as the circumference and the area of the aortic annulus were measured. Multi-Class Receiver-Operator-Curve analyses were used to determine the predictive value of all variables and to define optimal cutoff-values. RESULTS: Differences between patients who underwent implantation of the small, medium or large prosthesis were significant for all except the large vs. medium CoreValve (all p's<0.05. Furthermore, mean diameter, annulus area and circumference had equally high predictive value for prosthesis size for both manufacturers (multi-class AUC's: 0.80, 0.88, 0.91, 0.88, 0.88, 0.89. Using the calculated optimal cutoff-values, prosthesis size is predicted correctly in 85% of cases. CONCLUSION: CT-based aortic root measurements permit excellent prediction of the prosthesis size considered optimal during TAVI.

  10. A 2D panoramic surgical stent imaging: Complete arch mandibular implant fixed prosthesis along with bar supported maxillary over denture

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Singhal

    2017-01-01

    Full Text Available Successful rehabilitation of a patient should restore function, esthetic, and speech by prosthesis. Treatment modalities vary from patient to patient. Semi-precision attachments and implants offer several advantages over the traditional approach. The aim and objective of this report was to assess a case of a 55-year-old female patient who had lost all her teeth, except maxillary canines #13 and #23 and with severe bone loss in the mandible. Tooth-supported bar attachment was planned for maxilla, and a total of five dental implants were placed in the mandible using a flapless approach aided by radiographic gutta-percha surgical stents over panoramic two-dimensional imaging. Customized, radiographic stents help for the placement of implant in the view of paralleling and flapless surgery, completely. An immediate loading protocol is adopted as from day of the surgery to 6 weeks along with implant supported full arch fixed dentures after 4 months. The outcome of the treatment was impressive, and the patient gave a positive response with superb esthetics and functions.

  11. Implant-supported prosthesis misalignment related to the dental arch: a 14-year clinical follow-up.

    Science.gov (United States)

    das Neves, Flávio Domingues; Coró, Vitor; da Silva Neto, João Paulo; de Mattias Sartori, Ivete Aparecida; do Prado, Ricardo Alves

    2012-08-01

    The purpose of this study was to warn the dental community about a possible problem in function with partial implant-supported prostheses used for long periods. The misalignment between natural teeth and the implant-supported prosthesis on teeth 11 and 12, observed in a 14-year clinical follow-up, illustrates the fact. The metal-ceramic crowns were placed in 1995 after a rigorous occlusal adjustment. Evaluations were made at 4, 6, 9, and 14 years, when it was noticed that the restorations were positioned palatally and extruded in comparison with the natural teeth. After 9 years, a greater discrepancy was noticed, with anterior occlusion and esthetic changes. The possible causes have been discussed: occlusal problems, parafunctional habits, and natural movement. The first 2 options were discarded after clinical analysis and diagnosis. Therefore, the natural movement probably deriving from an interaction of mechanical and genetic factors might have been the cause. The implants do not have periodontal ligaments but rather ankylosis, so they do not suffer those movements. This case emphasizes the need to inform patients that implants can last more than 10 years in function, but this is not the case with restorations, which lose function and esthetics and must be replaced.

  12. A 2D Panoramic Surgical Stent Imaging: Complete Arch Mandibular Implant Fixed Prosthesis along with Bar Supported Maxillary over Denture

    Science.gov (United States)

    Singhal, Mukesh Kumar; Billing, Rumneet Kaur; Srivastava, Nitin; Khan, Zainab

    2017-01-01

    Successful rehabilitation of a patient should restore function, esthetic, and speech by prosthesis. Treatment modalities vary from patient to patient. Semi-precision attachments and implants offer several advantages over the traditional approach. The aim and objective of this report was to assess a case of a 55-year-old female patient who had lost all her teeth, except maxillary canines #13 and #23 and with severe bone loss in the mandible. Tooth-supported bar attachment was planned for maxilla, and a total of five dental implants were placed in the mandible using a flapless approach aided by radiographic gutta-percha surgical stents over panoramic two-dimensional imaging. Customized, radiographic stents help for the placement of implant in the view of paralleling and flapless surgery, completely. An immediate loading protocol is adopted as from day of the surgery to 6 weeks along with implant supported full arch fixed dentures after 4 months. The outcome of the treatment was impressive, and the patient gave a positive response with superb esthetics and functions. PMID:28839424

  13. Implant survival and crestal bone loss around extra-short implants supporting a fixed denture: the effect of crown height space, crown-to-implant ratio, and offset placement of the prosthesis.

    Science.gov (United States)

    Anitua, Eduardo; Alkhraist, Mohammad Hamdan; Piñas, Laura; Begoña, Leire; Orive, Gorka

    2014-01-01

    To determine the effect of crown height space, crown-to-implant ratio, and offset placement of a prosthesis on implant survival, crestal bone loss, and prosthetic complications; and to determine whether detrimental values for crown height space and crown-to-implant ratio exist for implant-supported restorations. Extra-short implants (length ≤6.5 mm) supporting a fixed denture in the posterior mandible and followed for at least 12 months were analyzed. Radiographic and clinical examinations were conducted to retrieve data about patients' dental and medical history, prosthetic complications, antagonist type, crown height space, crown-to-implant ratio, offset placement of the prosthesis, crestal bone loss, and implant failure. Thirty-four patients (mean age, 60 ± 10 years) with 45 extra-short implants participated in this study. Patients were followed for up to 4 years (mean, 2 years) and no implants were lost. The mean crown-to-implant ratio was 2.4 (range, 1.5 to 3.69). Mean crown height space was 17.05 ± 3.05 mm, and 65.4% of the implants had a crown height space in the range of 15 to 20 mm. About 90% of the implants had a distal or mesial offset placement greater than 1 mm. The type of antagonist significantly affected marginal bone loss around extra-short implants: bone loss was greatest for implants opposing a partial denture (mean, 1.28 ± 1.09 mm) and was lower for implants opposing a natural dentition (mean, 0.73 ± 0.60 mm) or a complete denture (mean, 0.89 ± 0.60 mm). Analysis of marginal bone loss and the factors crown-to-implant ratio, crown height space, and offset placement according to antagonist dentition indicated a significant positive correlation only between bone loss and crown height space. When an increased crown-to-implant ratio is present, crown height space may influence crestal bone loss more significantly.

  14. Force-to-failure of a simulated implant-supported complete fixed dental prosthesis reinforced with glass fiber.

    Science.gov (United States)

    Goldberg, Jack; Ronaghi, Gelareh; Phark, Jin-Ho; Jivraj, Sajid; Chee, Winston

    2017-08-01

    The joint adjacent to the cantilevered section of an implant-supported complete fixed dental prosthesis (ICFDP) undergoes the most stress because of force magnification in this area, making it more prone to mechanical failure. The purpose of this in vitro study was to evaluate the ultimate force-to-failure distal to the terminal implant of a simulated ICFDP reinforced with glass fiber compared with that of a conventionally fabricated prosthesis. Thirty ICFDPs with bilateral distal cantilevers were fabricated and divided into 3 groups: the not-reinforced (NR) group was processed without reinforcement, the glass-fiber-reinforced (GR) group was reinforced with glass fiber, and the titanium-reinforced (TR) group was fabricated with a titanium bar. The specimens were screw-retained onto a standardized mandibular model with 4-implant analogs embedded in acrylic resin. All groups were processed using heat-polymerized acrylic resin. After 24 hours, the cantilevers were loaded to fracture (in N) 10 mm away from the center of the most distal analog under compression at a crosshead speed of 1 mm/min. Statistical analysis of data was performed using a 1-way analysis of variance (ANOVA) model by using Tukey B post hoc comparison procedures (α=.05). Data revealed the mean fracture load of the NR group was 1073 ±108 N, 1400.75 ±123.53 N for the GR group, and 1652.78 ±274.14 N for the TR group. Statistically significant differences (P<.05) were found among all 3 groups. Comparison between the left and right side of the tested prostheses did not show any significant differences (P=.595). A fiber-reinforced ICFDP provides better biomechanical properties than an unreinforced one, which may allow its longer-term use as an interim ICFDP. However, the titanium bar ICFDP still provided the best resistance to fracture. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  15. Penile prosthesis implant with bi-triangular excision and graft for surgical therapy of Peyronie’s disease: A case report

    Directory of Open Access Journals (Sweden)

    Alexandre de Freitas Miranda

    2016-01-01

    Full Text Available We present a case of a 65-year-old man, who presented with moderate erectile dysfunction and a dorsal penile deviation of 60° caused by Peyronie’s disease. The patient underwent bi-triangularshaped plaque excision, followed by grafting and implantation of inflatable penile prosthesis. Complete penile straightening, without mechanical or geometric abnormalities, was achieved using bi-triangular excision and grafting. Postoperatively, the patient reported high satisfaction with the results and could perform sexual intercourse naturally. This novel technique corrects any degree of penile curvature, permits malleable and semi-rigid penile prosthesis implantation, avoids penile length loss, and eliminates additional incisions. To our knowledge, this case is the first in the literature in which the bi-triangular technique was successfully used for penile prosthesis implantation secondary to Peyronie’s disease. This new technique appears to be a good solution to correct penile curvature during penile prosthesis implantation for the treatment of Peyronie’s disease associated with erectile dysfunction.

  16. War injuries of the blood vessels of the extremities

    Directory of Open Access Journals (Sweden)

    Radulović Svetozar

    2002-01-01

    Full Text Available Treatment results of 200 injured with the lesions of 282 magisterial blood vessels were analyzed. All were combat injuries, and the majority was caused by the fragments of explosive device. The mechanism of such the injuries produced large defects of soft tissues as well as the high level of the wound contamination, which aggravated reconstructive procedures and increased the risk of infection. In the majority of cases anatomic reconstruction of the artery was performed, and the ligature was used only in the case of graft infection and in the injuries of one artery of the lower leg or the forearm. The majority of injuries was solved by lateral suture or patch plastic, since postoperative constriction caused by those methods did not cause greater hemodynamic disorders due to the size of venous lumen. The duration of ischemic interval was of the utmost importance for the favorable final result of the treatment, as well as the adequate debridement of the wound, good soft-tissue cover of the reconstructed blood vessel and precise a traumatic technique. Total percentage of amputations was 14.5%, and all were involving the lower extremities, and were mostly caused by popliteal artery lesion.

  17. Intra-epithelially entrapped blood vessels in ameloblastoma.

    Science.gov (United States)

    Siar, Chong Huat; Ishak, Ismadi; Ng, Kok Han

    2015-05-01

    The ameloblastoma is a benign but locally aggressive odontogenic neoplasm with a high recurrence rate. While significant progress has been made in our understanding regarding the role of tumoral vasculature relative to the diverse behavioral characteristics of this tumor, no attention has been paid to a distinct subset of blood vessels entrapped within its epithelial compartment. As vascular niches are known to influence tumoral growth, clarification of these vessels is important. The objectives of this study were to investigate the morphologic characteristics of intra-epithelially entrapped blood vessels (IEBVs) in ameloblastoma and to speculate on their relevance. Here, we evaluated the frequency, microvessel density (MVD), morphology, and distribution pattern of IEBVs in 77 ameloblastoma of different subtypes based on their immunoreactivity for endothelial markers (CD34, CD31, CD105), vascular tight junction protein (claudin-5), pericyte [α-smooth muscle actin (α-sma)], and vascular basement membrane (collagen IV). IEBVs were heterogeneously detected in ameloblastoma. Their mean MVD (CD34 = 15.46 ± 7.25; CD31 = 15.8 ± 5.04; CD105 = 0.82 ± 0.51) showed no significant correlation with different subtypes, and between primary and recurrent tumors (P > 0.05). These microvessels may occur as single/clusters of capillary sprouts, or formed compressed branching/non-branching slits entrapped within the epithelial compartment, and in direct apposition with polyhedral/granular neoplastic epithelial cells. They expressed proteins for endothelial tight junctions (claudin-5-positive) and pericytes (α-sma-positive) but had deficient basement membrane (collagen IV weak to absent). Aberrant expression for CD34, CD31, and CD105 in tumor epithelium was variably observed. Although rare in occurrence, identification of IEBVs in ameloblastoma could potentially represent a new paradigm for vascular assessment of this neoplasm. © 2014 John Wiley & Sons A/S. Published by John

  18. [Function of prosthesis components in lower limb amputees with bone-anchored percutaneous implants : Biomechanical aspects].

    Science.gov (United States)

    Blumentritt, S

    2017-05-01

    Bone anchorage of an artificial limb has been proven to be an alternative intervention for amputees when prosthesis use is seriously reduced because of stump problems. Little is known about how prosthesis components interact with bone and joints and which potential the optimum use provides with respect to quality of treatment of leg amputees. Does osseointegration influence the motor activity of residual limbs differently compared with socket prostheses? How should prosthesis components be aligned? What type of prosthetic knee joints should be preferred in transfemoral amputees? Transfer of biomechanical knowledge of socket prosthetics to bone-anchored prostheses. Pilot studies with a limited number of amputees. Force transmission at the interface between the prosthesis and residual limb stump is completely different for osseointegrated fixation and socket design; however, the number of muscles available for control remains unchanged. Because the iliotibial tract is missing, bending moments of the femur are expected to be greater. Prosthetic alignment is very critical for gait pattern and the basic rules seem to be the same as for socket design. The foot position determines the knee function for below-knee amputees. The position of the femur influences the gait pattern of above-knee amputees. The lowest risk of falls and best functional properties are shown by microprocessor controlled knee joints. Osseointegrated leg prostheses have some biomechanical advantages over the socket design. Since rehabilitation quality is clearly affected the prosthetic alignment has to be done carefully and precisely. As a rule microprocessor controlled knee joints are indicated.

  19. Prosthesis failure within 2 years of implantation is highly predictive of infection.

    Science.gov (United States)

    Portillo, María Eugenia; Salvadó, Margarita; Alier, Albert; Sorli, Lluisa; Martínez, Santos; Horcajada, Juan Pablo; Puig, Lluis

    2013-11-01

    The outcome of revision surgery depends on accurate determination of the cause of prosthesis failure because treatment differs profoundly among aseptic loosening, mechanical failure, and prosthetic joint infections (PJI). We sought to determine (1) the predictive role of the interval from primary to revision surgery in determining the reason for prosthesis failure of a hip, knee, shoulder, or elbow arthroplasty, and (2) whether positive cultures during revision surgery for aseptic loosening were associated with shorter event-free survival of the prosthesis. All patients undergoing revision surgery between July 2010 and January 2012 were included in a prospective cohort of 112 patients, and were classified as having had failure from aseptic loosening (56%), mechanical failure (15%), or PJI (29%). To make the diagnosis of PJI, at surgery we used a standardized enhanced diagnostic approach in all patients including sampling of five periprosthetic tissue specimens, sonication of removed prosthetic components, prolonged incubation of aerobic and anaerobic cultures, and multiplex PCR of sonication fluid in aseptic loosening cases. Kaplan-Meier survival and Cox proportional hazards regression analysis were performed. The median time from primary to revision surgery was (p prosthesis failure.

  20. A Comparative Analysis on Two Types of Oral Implants, Bone-Level and Tissue-Level, with Different Cantilever Lengths of Fixed Prosthesis.

    Science.gov (United States)

    Mosavar, Alireza; Nili, Monireh; Hashemi, Sayed Raouf; Kadkhodaei, Mahmoud

    2017-06-01

    Depending on esthetic, anatomical, and functional aspects, in implant-prosthetic restoration of a completely edentulous jaw, the selection of implant type is highly important; however, bone- and tissue-level implants and their stress distribution in bone have not yet been comparatively investigated. Hence, finite element analysis was used to study the influence of cantilever length in a fixed prosthesis on stress distribution in peri-implant bone around these two types of oral implants. A 3D edentulous mandible was modeled. In simulations, a framework with four posterior cantilever lengths and two types of implants, bone-level and tissue-level, was considered. A compressive load was applied to the distal regions of the cantilevers, and the von-Mises stress of peri-implant bone was investigated. The independent t-test and the Pearson correlation coefficient analyzed the results (α = 0.05). Stresses in the cortical bone around the bone-level implants were greater than those in the tissue-level implants with the same cantilever length. In addition, by extending the cantilever length, the stress values in peri-implant bone increased. Therefore, when the cantilever was at its maximum length, the maximum stress was in cortical bone and around the bone-level distal implants. The results of the present study indicate that treatment with tissue-level implants is potentially more advantageous than with bone-level implants for implant-supported fixed prostheses. © 2015 by the American College of Prosthodontists.

  1. Fixed prosthesis with a milled bar for correcting misangled implants: a clinical report.

    Science.gov (United States)

    Lee, Jae-Hoon; Frias, Val; Woo, Changwoo; Maiberg, Roman

    2007-03-01

    The fabrication of fixed implant-supported prostheses for edentulous maxillae may result in esthetic and functional problems due to the unfavorable angulations of the supporting implants. This article presents a technique that uses a metal mesosubstructure prepared with a conventional milling technique and palatal set screws to compensate for an unfavorable implant position, thereby providing a more esthetically acceptable and functional result.

  2. Fabrication of a screw-retained fixed provisional prosthesis supported by dental implants.

    Science.gov (United States)

    Kökat, Ali Murat; Akça, Kivanç

    2004-03-01

    Screw-retained provisional implant-supported prostheses may have advantages over cement-retained prostheses in certain situations. This article describes a technique for fabrication of screw-retained provisional acrylic resin implant-supported prostheses from the modified metal components provided with the implant.

  3. [Muscle efficiency in total shoulder prosthesis implantation: dependence on position of the humeral head and rotator cuff function].

    Science.gov (United States)

    Klages, A; Hurschler, C; Wülker, N; Windhagen, H

    2001-09-01

    Modern shoulder prostheses permit an anatomic reconstruction of the joint, although the biomechanical advantages are not proven. The goal of this study was to investigate the relationship between position of the humeral head and function of the shoulder prosthesis (muscle efficiency). Shoulder elevation-motion and rotator cuff defects were simulated in vitro in a robot-assisted shoulder simulator. The EPOCA Custom Offset shoulder prosthesis (Argomedical AG, Cham, CH) was implanted in seven normal shoulders (77 +/- 20 kg, 55 +/- 14 years). Active elevation was simulated by hydraulic cylinders, and scapulothoratic motion by a specially programmed industrial robot. Muscle efficiency (elevation-angle/muscle-force of the deltoid muscle) was measured in anatomic (ANA), medialised (MED) and lateralised (LAT) positions of the humeral head, with or without rotator cuff muscle deficiency. Medialisation increased efficiency by 0.03 +/- 0.04 deg/N (p = 0.022), lateralisation decreased it by 0.04 +/- 0.06 deg/N (p = 0.009). Supraspinatus muscle deficiency increased the deltoid force required to elevate the arm, and thus decreased efficiency (ANA p = 0.091, MED p = 0.018, LAT p = 0.028). The data confirm that the position of the humeral head affects the mechanics of total shoulder arthroplasty. Medialisation increases efficiency of the deltoid muscle and may prove useful in compensating isolated supraspinatus muscle deficiency. Lateralisation, in contrast, leads to an unfavorable situation.

  4. Construction of an implant-retained auricular prosthesis with the aid of contemporary digital technologies: a clinical report.

    Science.gov (United States)

    Hatamleh, Muhanad M; Watson, Jason

    2013-02-01

    Implant-retained auricular prostheses are a successful treatment modality for children with microtia. They involve only minor surgical intervention of implant placement and result in an esthetically pleasing outcome. Integration of digital technologies (DT) in the prosthetic reconstruction process is a new approach toward enhancing outcomes. In this report we present a case of auricular prosthetic reconstruction following two implant placements in the right mastoid region. The ear prosthesis was constructed with the aid of various DTs. A structured light laser scanner was used to digitize the nondefect patient ear. The digitized 3D ear was then manipulated in specialist software, mirrored to reflect the opposing side, and a Rapid Prototyping (RP) machine (Z-Corp) was used to manufacture the soft tissue required. This RP-mirrored ear model allows very accurate reproduction to replicate missing soft tissue. A color Spectrometer was used to accurately reproduce skin tones. The use of these technologies is now routine practice at our unit. They enhance prosthetic outcomes and esthetics, save the prosthetist's time, and are digitally stored and subsequently readily available and reproducible. © 2012 by the American College of Prosthodontists.

  5. CT-angiography-based evaluation of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI)-predictive value and optimal thresholds for major anatomic parameters.

    Science.gov (United States)

    Schwarz, Florian; Lange, Philipp; Zinsser, Dominik; Greif, Martin; Boekstegers, Peter; Schmitz, Christoph; Reiser, Maximilian F; Kupatt, Christian; Becker, Hans C

    2014-01-01

    To evaluate the predictive value of CT-derived measurements of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI) and to calculate optimal cutoff values for the selection of various prosthesis sizes. The local IRB waived approval for this single-center retrospective analysis. Of 441 consecutive TAVI-patients, 90 were excluded (death within 30 days: 13; more than mild aortic regurgitation: 10; other reasons: 67). In the remaining 351 patients, the CoreValve (Medtronic) and the Edwards Sapien XT valve (Edwards Lifesciences) were implanted in 235 and 116 patients. Optimal prosthesis size was determined during TAVI by inflation of a balloon catheter at the aortic annulus. All patients had undergone CT-angiography of the heart or body trunk prior to TAVI. Using these datasets, the diameter of the long and short axis as well as the circumference and the area of the aortic annulus were measured. Multi-Class Receiver-Operator-Curve analyses were used to determine the predictive value of all variables and to define optimal cutoff-values. Differences between patients who underwent implantation of the small, medium or large prosthesis were significant for all except the large vs. medium CoreValve (all p'sprosthesis size for both manufacturers (multi-class AUC's: 0.80, 0.88, 0.91, 0.88, 0.88, 0.89). Using the calculated optimal cutoff-values, prosthesis size is predicted correctly in 85% of cases. CT-based aortic root measurements permit excellent prediction of the prosthesis size considered optimal during TAVI.

  6. [Acquired thrombotic thrombocytopenic purpura after vascular prosthesis implantation for impending rupture of an abdominal aortic aneurysm].

    Science.gov (United States)

    Naito, Chiaki; Ogawa, Yoshiyuki; Yanagisawa, Kunio; Ishizaki, Takuma; Mihara, Masahiro; Handa, Hiroshi; Isonishi, Ayami; Hayakawa, Masaki; Matsumoto, Masanori; Nojima, Yoshihisa

    2016-03-01

    Acquired thrombotic thrombocytopenic purpura (TTP) is caused by autoantibodies against ADAMTS13. TTP patients run a rapidly fatal course unless immediate plasma exchange (PEX) is initiated upon diagnosis. Herein, we report a 72-year-old man with TTP, which developed after he underwent artificial blood vessel replacement surgery for an abdominal aneurysm with impending rupture. In the perioperative period, the patient received several platelet transfusions for severe thrombocytopenia (minimum platelet count: 0.6×10(4)/μl). Thereafter, he was admitted to our department for rapidly progressing coma with multiple cerebral infarctions, and was transferred to the ICU. Based on the tentative diagnosis of TTP, we immediately began PEX and steroid pulse therapy. The diagnosis was confirmed thereafter by markedly reduced ADAMTS13 activity (<0.5%) and his being positive for the ADAMTS13 inhibitor. We performed PEX for five consecutive days and administered high-dose prednisolone (PSL). On the second hospital day (HD), his platelet count rose along with improvement of his consciousness level. The ADAMTS13 inhibitor was not detected on the 10th HD. TTP did not relapse and his general condition improved despite tapering of PSL. In this case, by closely monitoring ADAMTS13-related parameters and minimizing the number of plasma exchanges, the patient was able to achieve a remission without the use of boosting inhibitors.

  7. Pattern of blood vessels in eyes with coloboma

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    Gopal Lingam

    2013-01-01

    Full Text Available Background: Choroidal coloboma, especially with optic disc involvement affects the blood vessel (BV pattern in the fundus. Aim: The aim of this study was to report the observations on the pattern of retinal BVs in eyes with fundus coloboma. Design: Retrospective observational study. Materials and Methods: Twenty four eyes of 19 patients with fundus coloboma and the disc involvement in the coloboma was classified according to a previous publication. Results: Four varieties of BVs were identified in the area of coloboma - BVs that were continuous with those arising from the optic disc; vessels emanating from the floor of coloboma whose continuity with central retinal artery or its branches could be indirectly established; and those emanating from the floor of coloboma whose continuity with central retinal artery could not be established. In addition, extraocular BVs were visible through the thinned sclera. The retinal BVs often traversed the coloboma to reach the normal retina. The disc itself was found to be small and had no physiological cup (if not colobomatous. Conclusions: One should be aware of the major BVs transgressing the coloboma while performing relaxing cuts in the intercalary membrane, during the surgery for retinal detachments in eyes with coloboma. Physiological cup is usually absent (when the disc is not colobomatous. Hence, any cupping in such eyes should be viewed with suspicion.

  8. Computerized Reconstruction of Pulpal Blood Vessels Examined under Confocal Microscope

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    Digka Anna

    2015-03-01

    Full Text Available The purpose of this study was the evaluation of 3 different histological methods for studying pulpal blood vessels in combination with 2 types of confocal microscope and computer assisted 3-dimensional reconstruction. 10 human, healthy, free of restorations or caries teeth that were extracted for orthodontic reasons were used. From these teeth, the pulp tissues of 5 were removed, fixed in formalin solution, dehydrated and embedded in paraffin. Serial cross sections 5μm thick were taken from 3 of the above mentioned pulpal tissues and stained with CD34 according to the immunohistochemical ABC technique, while the rest 2 were stained with CD34 and Cy5 by means of immunofluorescence after serial cross sectioning of 10μm. 5 of the 10 teeth were fixed, decalcified, serial cross sectioned (30μm thickness and stained with eosin. The physical sections were examined under 2 types of confocal laser microscope. Serial images were taken for each section, alignment of the images was followed and finally 3-dimensional reconstructions of the pulpal vessels were achieved.

  9. Heterogeneity of muscarinic receptor subtypes in cerebral blood vessels

    International Nuclear Information System (INIS)

    Garcia-Villalon, A.L.; Krause, D.N.; Ehlert, F.J.; Duckles, S.P.

    1991-01-01

    The identity and distribution of muscarinic cholinergic receptor subtypes and associated signal transduction mechanisms was characterized for the cerebral circulation using correlated functional and biochemical investigations. Subtypes were distinguished by the relative affinities of a panel of muscarinic antagonists, pirenzepine, AF-DX 116 [11-2-[[2-[diethylaminomethyl]- 1-piperidinyl]acetyl]-5,11-dihydro-6H- pyrido[2,3-b][1,4]benzodiazepine-6-one], hexahydrosiladifenidol, methoctramine, 4-diphenylacetoxy-N-methylpiperidine methobromide, dicyclomine, para-fluoro-hexahydrosiladifenidol and atropine. Muscarinic receptors characterized by inhibition of [3H]quinuclidinylbenzilate binding in membranes of bovine pial arteries were of the M2 subtype. In contrast pharmacological analysis of [3H]-quinuclidinylbenzilate binding in bovine intracerebral microvessels suggests the presence of an M4 subtype. Receptors mediating endothelium-dependent vasodilation in rabbit pial arteries were of the M3 subtype, whereas muscarinic receptors stimulating endothelium-independent phosphoinositide hydrolysis in bovine pial arteries were of the M1 subtype. These findings suggest that characteristics of muscarinic receptors in cerebral blood vessels vary depending on the type of vessel, cellular location and function mediated

  10. Impact of patient-prosthesis mismatch after transcatheter aortic valve-in-valve implantation in degenerated bioprostheses.

    Science.gov (United States)

    Seiffert, Moritz; Conradi, Lenard; Baldus, Stephan; Knap, Malgorzata; Schirmer, Johannes; Franzen, Olaf; Koschyk, Dietmar; Meinertz, Thomas; Reichenspurner, Hermann; Treede, Hendrik

    2012-03-01

    Transcatheter valve-in-valve implantation is evolving as an alternative to reoperative valve replacement in high-risk patients with degenerated bioprostheses. Nevertheless, hemodynamic performance is limited by the previously implanted xenograft. We report our experience with patient-prosthesis mismatch (PPM) after valve-in-valve implantation in the aortic position. Eleven patients (aged 79.3 ± 6.1 years) received transapical implantation of a balloon-expandable pericardial heart valve into a degenerated bioprosthesis (size, 23.9 ± 1.6 mm; range, 21-27 mm) in the aortic position. All patients were considered high risk for surgical valve replacement (logistic European System for Cardiac Operative Risk Evaluation, 31.8% ± 24.1%). Severe PPM was defined as an indexed effective orifice area less than 0.65 cm(2)/m(2), determined by discharge echocardiography. Severe PPM was evident in 5 patients (group 1) and absent in 6 patients (group 2). Mean transvalvular gradients decreased from 29.2 ± 15.4 mm Hg before implantation to 21.2 ± 9.7 mm Hg at discharge (group 1) and from 28.2 ± 9.0 mm Hg before implantation to 15.2 ± 6.5 mm Hg at discharge (group 2). Indexed effective orifice area increased from 0.5 ± 0.1 cm(2)/m(2) to 0.6 ± 0.1 cm(2)/m(2) and from 0.6 ± 0.3 cm(2)/m(2) to 0.8 ± 0.3 cm(2)/m(2). Aortic regurgitation decreased from grade 2.0 ± 1.1 to 0.4 ± 0.5 overall. No differences in New York Heart Association class improvement or survival during follow-up were observed. One patient required reoperation for symptomatic PPM 426 days after implantation. Valve-in-valve implantation can be performed in high-risk surgical patients to avoid reoperation. However, PPM frequently occurs, making adequate patient selection crucial. Small bioprostheses (body surface area less than 1.8 m(2). Larger prostheses seem to carry a lower risk for PPM. Although no delay in clinical improvement was seen at short-term, 1 PPM-related surgical intervention raises concern regarding

  11. Blood Vessel Enhancement and Segmentation for Screening of Diabetic Retinopathy

    Directory of Open Access Journals (Sweden)

    Ibaa Jamal

    2012-06-01

    Full Text Available Diabetic retinopathy is an eye disease caused by the increase of insulin in blood and it is one of the main cuases of blindness in idusterlized countries. It is a progressive disease and needs an early detection and treatment. Vascular pattern of human retina helps the ophthalmologists in automated screening and diagnosis of diabetic retinopathy. In this article, we present a method for vascular pattern ehnacement and segmentation. We present an automated system which uses wavelets to enhance the vascular pattern and then it applies a piecewise threshold probing and adaptive thresholding for vessel localization and segmentation respectively. The method is evaluated and tested using publicly available retinal databases and we further compare our method with already proposed techniques.

  12. Locating abnormalities in brain blood vessels using parallel computing architecture.

    Science.gov (United States)

    Adeshina, A M; Hashim, R; Khalid, N E A; Abidin, S Z Z

    2012-09-01

    CT and MRI scans are widely used in medical diagnosis procedures, but they only produce 2-D images. However, the human anatomical structure, the abnormalities, tumors, tissues and organs are in 3-D. 2-D images from these devices are difficult to interpret because they only show cross-sectional views of the human structure. Consequently, such circumstances require doctors to use their expert experiences in the interpretation of the possible location, size or shape of the abnormalities, even for large datasets of enormous amount of slices. Previously, the concept of reconstructing 2-D images to 3-D was introduced. However, such reconstruction model requires high performance computation, may either be time-consuming or costly. Furthermore, detecting the internal features of human anatomical structure, such as the imaging of the blood vessels, is still an open topic in the computer-aided diagnosis of disorders and pathologies. This paper proposes a volume visualization framework using Compute Unified Device Architecture (CUDA), augmenting the widely proven ray casting technique in terms of superior qualities of images but with slow speed. Considering the rapid development of technology in the medical community, our framework is implemented on Microsoft.NET environment for easy interoperability with other emerging revolutionary tools. The framework was evaluated with brain datasets from the department of Surgery, University of North Carolina, United States, containing around 109 MRA datasets. Uniquely, at a reasonably cheaper cost, our framework achieves immediate reconstruction and obvious mappings of the internal features of human brain, reliable enough for instantaneous locations of possible blockages in the brain blood vessels.

  13. Intraluminal Palmaz stent implantation. First clinical case report on a balloon-expandable vessel prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Palmaz, J.C.; Richter, G.M.; Noeldge, G.; Kauffmann, G.W.; Wenz, W.

    1987-12-01

    A 74-year-old patient suffering from severe iliac artery stenosis and claudication was chosen to be the first candidate in the world to receive the Palmaz stent, a balloon-expandable intraluminal stent. This procedure was done in the Department of Radiology, University of Freiburg, FRG. The intervention and postprocedural course were uneventful. His walking distance improved from less than 100 m to unlimited walking capacity. The intra-arterial pressure gradient and ankle-arm pressure ratio also returned to normal.

  14. Clinical Implantation with the novel D-13 prosthesis for inguinal hernioplasty: A retrospective cohort study.

    Science.gov (United States)

    Gao, Peng-Zhi; Li, Ming; Yu, Ying-Jian; Hao, Xiang-Dong; Li, Wu-Zi; Rong, Ya-Jun; Zheng, Zhi-Gang; Meng, Ning

    2015-05-01

    Using a mesh to repair inguinal hernias is now a standard procedure that is widely accepted as superior to primary suture repair. Although a variety of meshes are available, individual meshes may have their own unattractive features. This retrospective study examines the efficacy of our originally designed D-13 prosthesis, which is used in patients with inguinal hernias. A total of 305 patients who underwent a herniorrhaphy between January 2009 and March 2011 were included in this study. The recurrent rate, chronic pain and feeling of a foreign body were examined at a 3-year follow-up. The D-13 prosthesis, made from clear polypropylene monofilament mesh, was originally designed by the first author of this study and constructed with the upper and lower pieces of polypropylene mesh having different shapes and sizes. Both pieces are linked together by a connector. The mesh is well tolerated. At a 3-year follow-up, only two patients had a foreign body sensation at the operative site, and three patients had recurrent hernias. The unique design of the D-13 prosthesis with two pieces of mesh provided encouraging long-term outcome for hernia recurrence, chronic pain and the feeling of a foreign body. Copyright © 2015 IJS Publishing Group Limited. All rights reserved.

  15. An angiogenesis platform using a cubic artificial eggshell with patterned blood vessels on chicken chorioallantoic membrane.

    Science.gov (United States)

    Huang, Wenjing; Itayama, Makoto; Arai, Fumihito; Furukawa, Katsuko S; Ushida, Takashi; Kawahara, Tomohiro

    2017-01-01

    The chorioallantoic membrane (CAM) containing tiny blood vessels is an alternative to large animals for studies involving angiogenesis and tissue engineering. However, there is no technique to design the direction of growing blood vessels on the CAM at the microscale level for tissue engineering experiments. Here, a methodology is provided to direct blood vessel formation on the surface of a three-dimensional egg yolk using a cubic artificial eggshell with six functionalized membranes. A structure on the lateral side of the eggshell containing a straight channel and an interlinked chamber was designed, and the direction and formation area of blood vessels with blood flow was artfully defined by channels with widths of 70-2000 μm, without sharply reducing embryo viability. The relationship between the size of interlinked chamber and the induction of blood vessels was investigated to establish a theory of design. Role of negative and positive pressure in the induction of CAM with blood vessels was investigated, and air pressure change in the culture chamber was measured to demonstrate the mechanism for blood vessel induction. Histological evaluation showed that components of CAM including chorionic membrane and blood vessels were induced into the channels. Based on our design theory, blood vessels were induced into arrayed channels, and channel-specific injection and screening were realized, which demonstrated proposed applications. The platform with position- and space-controlled blood vessels is therefore a powerful tool for biomedical research, which may afford exciting applications in studies involved in local stimulation of blood vessel networks and those necessary to establish a living system with blood flow from a beating heart.

  16. 3-D MDT with spherical targets by bilinear interpolation for determining blood velocity profiles including the vessel wall effect

    Science.gov (United States)

    Choomphon-anomakhun, Natthaphon; Natenapit, Mayuree

    2018-02-01

    A numerical simulation of three-dimensional (3-D) implant assisted-magnetic drug targeting (IA-MDT) using ferromagnetic spherical targets, including the effect from the vessel wall on the blood flow, is presented. The targets were implanted within arterioles and subjected to an externally uniform applied magnetic field in order to increase the effectiveness of targeting magnetic drug carrier particles (MDCPs). The capture area (As) of the MDCPs was determined by inspection of the particle trajectories simulated from the particle equations of motion. The blood flow velocities at any particle position around the target were obtained by applying bilinear interpolation to the numerical blood velocity data. The effects on As of the type of ferromagnetic materials in the targets and MDCPs, average blood flow rates, mass fraction of the ferromagnetic material in the MDCPs, average radii of MDCPs (Rp) and the externally applied magnetic field strength (μ0H0) were evaluated. Furthermore, the appropriate μ0H0 and Rp for the IA-MDT design is suggested. In the case of the SS409 target and magnetite MDCPs, dimensionless capture areas ranging from 4.1- to 12.4 and corresponding to particle capture efficiencies of 31-94% were obtained with Rp ranging from 100- to 500 nm, weight fraction of 80%, μ0H0 of 0.6 T and an average blood flow rate of 0.01 ms-1. In addition, the more general 3-D modelling of IA-MDT in this work is applicable to IA-MDT using spherical targets implanted within blood vessels for both laminar and potential blood flows including the wall effect.

  17. Blood Vessel Normalization in the Hamster Oral Cancer Model for Experimental Cancer Therapy Studies

    Energy Technology Data Exchange (ETDEWEB)

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz; Marcela A. Garabalino; Andrea Monti Hughes; Elisa M. Heber; Emiliano C. C. Pozzi; David W. Nigg; Veronica A. Trivillin; Amanda E. Schwint

    2012-07-01

    Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer. Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls. Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor blood vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h. Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy.

  18. Sutureless Aortic Prosthesis Implantation: the First Brazilian Experience with Perceval Device.

    Science.gov (United States)

    Tagliari, Ana Paula; de Moura, Leandro; Dussin, Luiz Henrique; Saadi, Eduardo Keller

    2016-01-01

    This is a report of the first Brazilian experience with the Perceval sutureless aortic prosthesis in two patients with severe aortic stenosis. Transesophageal echocardiography was used during the procedure. The aortotomy was performed 1 cm above the sinotubular junction, followed by leaflets removal and decalcification. Correct valve size was selected, device released and an accommodation balloon used. The cardiopulmonary bypass times were 47 and 38 min and the cross-clamp times were 38 and 30 min. There was a significant decrease in mean gradients (41 and 75 mmHg preoperatively; 7 and 8 mmHg postoperatively). There was no major complication or paravalvular leak.

  19. Improvements in vision-related quality of life in blind patients implanted with the Argus II Epiretinal Prosthesis.

    Science.gov (United States)

    Duncan, Jacque L; Richards, Thomas P; Arditi, Aries; da Cruz, Lyndon; Dagnelie, Gislin; Dorn, Jessy D; Ho, Allen C; Olmos de Koo, Lisa C; Barale, Pierre-Olivier; Stanga, Paulo E; Thumann, Gabriele; Wang, Yizhong; Greenberg, Robert J

    2017-03-01

    The purpose of this analysis is to report the change in quality of life (QoL) after treatment with the Argus II Epiretinal Prosthesis in patients with end-stage retinitis pigmentosa. The Vision and Quality of Life Index (VisQoL) was used to assess changes in QoL dimensions and overall utility score in a prospective 30-patient single-arm clinical study. VisQoL is a multi-attribute instrument consisting of six dimensions (injury, life, roles, assistance, activity and friendship) that may be affected by visual impairment. Within each dimension, patients were divided into two groups based on how much their QoL was affected by their blindness at baseline (moderate/severe or minimal). Outcomes were compared within each dimension sub-group between baseline and the combined follow-up periods using the Friedman test. In addition, data from the six dimensions were combined into a single utility score, with baseline data compared to the combined follow-up periods. Overall, 80 per cent of the patients reported difficulty in one or more dimensions pre-implant. Composite VisQoL utility scores at follow-up showed no statistically significant change from baseline; however, in three of the six VisQoL dimensions (injury, life and roles), patients with baseline deficits showed significant and lasting improvement after implantation with Argus II. In two of the three remaining dimensions (assistance and activity), data trended toward an improvement. In the final VisQoL dimension (friendship), none of the patients reported baseline deficits, suggesting that patients had largely adjusted to this attribute. Patients whose vision negatively affected them with respect to three VisQoL dimensions (that is, getting injured, coping with the demands of their life and fulfilling their life roles) reported significant improvement in QoL after implantation of the Argus II retinal prosthesis. Furthermore, the benefit did not deteriorate at any point during the 36-month follow-up, suggesting a long

  20. Clinical and Radiographic Assessment of Three-Implant-Supported Fixed-Prosthesis Rehabilitation of the Edentulous Mandible: Immediate Versus Delayed Loading.

    Science.gov (United States)

    Primo, Bruno Tochetto; Mezzari, Leonardo Marcos; da Fontoura Frasca, Luís Carlos; Linderman, Raquel; Rivaldo, Elken Gomes

    2018-03-15

    To evaluate and compare the clinical and radiographic outcomes of mandibular rehabilitation with fixed prostheses on three implants with immediate versus delayed loading. The sample comprised 21 patients who underwent treatment with immediate loading and 23 who received delayed loading. All had worn their prostheses for at least 18 months. Radiographic evaluation of bone loss was carried out in Adobe Photoshop CS5 by a single calibrated examiner using digitized panoramic radiographs. Clinical examination of the technical conditions of the prosthetic device assessed the condition of the acrylic resin base, dental occlusion, metal framework, presence of cover screws, screw fixation of the prosthesis and abutments, length of cantilever (effort) and resistance arms, presence of plaque on prosthetic abutments, and hygiene of the prosthesis. One implant failed in each group, resulting in a 95.23% treatment success rate with immediate loading and 95.65% with delayed loading (no statistically significant between-group difference). In the immediate-loading group, the mean bone loss was 1.96 ± 0.73 mm around central implants and 1.64 ± 0.84 mm at distal implants. In the delayed-loading group, the mean bone loss was 1.85 ± 0.67 mm around central implants and 1.70 ± 0.77 mm at distal implants. According to Student t test, there was no significant within-group difference in bone loss and no difference between the immediate-loading and delayed-loading groups. The only prosthesis-related complications that differed significantly between groups were "condition of the acrylic base," "occlusion," and "presence of right cover screw." There was no statistically significant association of lever arm ratio with peri-implant bone loss or bone loss on the mesial surfaces compared to the distal surfaces of the distal implants. The three-implant-supported fixed prosthesis protocol tested in this study proved to be a viable therapeutic strategy for mandibular edentulous patients with

  1. A different wax sculpture technique for implant-retained auricular prosthesis.

    Science.gov (United States)

    Demir, Necla; Cevik, Pınar; Okutan, Yener; Ozturk, A Nilgun; Colpan, Bahar

    2015-01-01

    Replacement of missing ears is a challenging task in which extensive array of materials and techniques have been employed. This article describes a different and simplified procedure for fabricating auricular prostheses very similar to the intact left ear of the patient. A 65-year-old male patient was referred to the Department of Prosthodontics with the loss of the right ear. In this case, the impression was made using hydrocolloid material (alginate) from the both defected and the opposite side. After hardening of the stone casts, a custom-made transparent splint plate was designed for the left auricular side. The splint was reversed and a cast model of the right auricular side was obtained as pouring the dental stone into transparent orthodontic splint. After getting the impression from cast model, conventional wax pattern and try on process was done. Finally, silicone elastomer was polymerized and the retention of the prosthesis acquired with the magnetic attachments. The technique described is economical, conventional, and time-saving. Furthermore, the prosthesis imitates the patient's intact auricular tissue.

  2. The vascular Ca2+-sensing receptor regulates blood vessel tone and blood pressure.

    Science.gov (United States)

    Schepelmann, M; Yarova, P L; Lopez-Fernandez, I; Davies, T S; Brennan, S C; Edwards, P J; Aggarwal, A; Graça, J; Rietdorf, K; Matchkov, V; Fenton, R A; Chang, W; Krssak, M; Stewart, A; Broadley, K J; Ward, D T; Price, S A; Edwards, D H; Kemp, P J; Riccardi, D

    2016-02-01

    The extracellular calcium-sensing receptor CaSR is expressed in blood vessels where its role is not completely understood. In this study, we tested the hypothesis that the CaSR expressed in vascular smooth muscle cells (VSMC) is directly involved in regulation of blood pressure and blood vessel tone. Mice with targeted CaSR gene ablation from vascular smooth muscle cells (VSMC) were generated by breeding exon 7 LoxP-CaSR mice with animals in which Cre recombinase is driven by a SM22α promoter (SM22α-Cre). Wire myography performed on Cre-negative [wild-type (WT)] and Cre-positive (SM22α)CaSR(Δflox/Δflox) [knockout (KO)] mice showed an endothelium-independent reduction in aorta and mesenteric artery contractility of KO compared with WT mice in response to KCl and to phenylephrine. Increasing extracellular calcium ion (Ca(2+)) concentrations (1-5 mM) evoked contraction in WT but only relaxation in KO aortas. Accordingly, diastolic and mean arterial blood pressures of KO animals were significantly reduced compared with WT, as measured by both tail cuff and radiotelemetry. This hypotension was mostly pronounced during the animals' active phase and was not rescued by either nitric oxide-synthase inhibition with nitro-l-arginine methyl ester or by a high-salt-supplemented diet. KO animals also exhibited cardiac remodeling, bradycardia, and reduced spontaneous activity in isolated hearts and cardiomyocyte-like cells. Our findings demonstrate a role for CaSR in the cardiovascular system and suggest that physiologically relevant changes in extracellular Ca(2+) concentrations could contribute to setting blood vessel tone levels and heart rate by directly acting on the cardiovascular CaSR.

  3. [Effects of high intensity focused ultrasound with SonoVue on blood vessels pathological examinations].

    Science.gov (United States)

    Qin, Yan; Bai, Jin; Li, Faqi; Wang, Zhibiao

    2010-12-01

    The injury of tumor blood vessels will break up the nutrition supply for the tumor. In this paper, we investigated the effects exerted by high intensity focused ultrasound (HIFU) combined with ultrasound microbubble agent on blood vessels. Ultrasound diagnosis was used to find the goat hepatic blood vessels each being approximately 3mm in diameter. HIFU was focused on the blood vessels. The acoustic power was 250W; HIFU irradiating Mode was line scan (the length of the line: 10 mm; speed: 3 mm/s; irradiating time: 30s). In the experimental group, 0.03 ml/kg SonoVue was injected into the goat before HIFU irradiation,while normal saline was given to the control group. The goats were killed at 24h after HIFU irradiation, then goat liver tissues and blood vessels of target area were taken out. HE staining and Victoria's blue and Ponceau's staining of tissue section showed that the endothelial cells of blood vessels dropped off and became necrosed, and the continuity of blood vessels was interrupted. HIFU combined with SonoVue will damage large blood vessels on HIFU focus, but there is no evident discrepancy between the group with SonoVue and the group without SonoVue.

  4. Determination of the critical buckling pressure of blood vessels using the energy approach.

    Science.gov (United States)

    Han, Hai-Chao

    2011-03-01

    The stability of blood vessels under lumen blood pressure is essential to the maintenance of normal vascular function. Differential buckling equations have been established recently for linear and nonlinear elastic artery models. However, the strain energy in bent buckling and the corresponding energy method have not been investigated for blood vessels under lumen pressure. The purpose of this study was to establish the energy equation for blood vessel buckling under internal pressure. A buckling equation was established to determine the critical pressure based on the potential energy. The critical pressures of blood vessels with small tapering along their axis were estimated using the energy approach. It was demonstrated that the energy approach yields both the same differential equation and critical pressure for cylindrical blood vessel buckling as obtained previously using the adjacent equilibrium approach. Tapering reduced the critical pressure of blood vessels compared to the cylindrical ones. This energy approach provides a useful tool for studying blood vessel buckling and will be useful in dealing with various imperfections of the vessel wall.

  5. The importance of psychosexual counselling in the re-establishment of organic and erotic functions after penile prosthesis implantation.

    Science.gov (United States)

    Pisano, F; Falcone, M; Abbona, A; Oderda, M; Soria, F; Peraldo, F; Marson, F; Barale, M; Fiorito, C; Gurioli, A; Frea, B; Gontero, P

    2015-01-01

    Although many studies about penile prosthesis implantation (PPI) have been published so far, only a small amount of them take into account patients and partners outcome in terms of satisfaction and erotic function. The aim of this study is to explore the value of psycosexual counselling in and the sexual and erotic function of penile prosthesis recipients. Thirty patients and their partners were randomised into two groups. In arm A (case group) patients and their partners underwent a multistep psychosexual counselling before and after surgery. In arm B (control group) surgery was performed without the specific psychosexual counselling scheme. Specific questionnaires (International Index of Erectile Function (IIEF) and the Sexual Daydreaming Scale (SDS)) were administered before surgery and 12 months afterwards. Twenty-four months postoperatively patients were asked to complete the Global Assessment Questions (GAQ) and the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS), while their partners were asked to answer to the EDITS partner's section. Between January 2009 and October 2011, we enrolled 30 patients undergoing PPI in our institution (15 in each arm). Twenty-four months postoperative follow-up is available for all of them. No significant differences between the two groups in terms of baseline questionnaires scores were observed. Mean IIEF score was significantly higher in case group (arm A 68.3, arm B 53.4, P-valuearm A patients and partners as compared with arm B. PPI with a pre- and postoperative psychosexual counselling scheme resulted in better postoperative sexual activity and erotic function for both patients and partners than PPI alone.

  6. The profile prosthesis: an aesthetic fixed implant-supported restoration for the resorbed maxilla.

    Science.gov (United States)

    Schnitman, P A

    1999-01-01

    This article discusses a method for the predictable fabrication of fixed detachable maxillary reconstructions that abut and precisely follow the gingival contours--regardless of implant angulation or position. The technique reorders the traditional implant protocol and delays abutment selection until the definitive tooth position has been established. In this manner, final abutment selection and framework design become a single, integrated process that results in improved aesthetics, reduced angulation difficulties, and elimination of the phonetic concerns traditionally associated with fixed maxillary prostheses.

  7. Photoelastic Stress Analysis Surrounding Implant-Supported Prosthesis and Alveolar Ridge on Mandibular Overdentures

    Directory of Open Access Journals (Sweden)

    Dorival Pedroso da Silva

    2010-01-01

    Full Text Available The purpose of this research was to evaluate the maximum stress around osseointegrated implants and alveolar ridge, in a mandible with left partial resection through a photoelastic mandibular model. The first group consisted of two implants: traditional model (T, implants placed in the position of both canines; fulcrum model (F, implants placed in the position of left canine CL and right lateral incisor LiR. Both models linked through a bar and clips. The second group was consisted of three implants, with implants placed in the position of both canines (CR and CL and the right lateral incisor (LiR, which composed four groups: (1 model with 3 “O” rings, (2 model 2 ERAs, bar with clips, (3 model 2 ERAs bar without clips; (4 model “O” ring bar and ERA. An axial and an oblique load of 6.8 kgf was applied on a overdenture at the 1st Pm, 2nd Pm, and 1st M. Results showed that the area around the left canine (CL was practically free of stress; the left lateral incisor (LiL developed only small tensions, and low stress in all the other cases; the right canine tooth suffered the largest concentrations of stress, mainly with the ERA retention mechanism.

  8. Captopril improves tumor nanomedicine delivery by increasing tumor blood perfusion and enlarging endothelial gaps in tumor blood vessels.

    Science.gov (United States)

    Zhang, Bo; Jiang, Ting; Tuo, Yanyan; Jin, Kai; Luo, Zimiao; Shi, Wei; Mei, Heng; Hu, Yu; Pang, Zhiqing; Jiang, Xinguo

    2017-12-01

    Poor tumor perfusion and unfavorable vessel permeability compromise nanomedicine drug delivery to tumors. Captopril dilates blood vessels, reducing blood pressure clinically and bradykinin, as the downstream signaling moiety of captopril, is capable of dilating blood vessels and effectively increasing vessel permeability. The hypothesis behind this study was that captopril can dilate tumor blood vessels, improving tumor perfusion and simultaneously enlarge the endothelial gaps of tumor vessels, therefore enhancing nanomedicine drug delivery for tumor therapy. Using the U87 tumor xenograft with abundant blood vessels as the tumor model, tumor perfusion experiments were carried out using laser Doppler imaging and lectin-labeling experiments. A single treatment of captopril at a dose of 100 mg/kg significantly increased the percentage of functional vessels in tumor tissues and improved tumor blood perfusion. Scanning electron microscopy of tumor vessels also indicated that the endothelial gaps of tumor vessels were enlarged after captopril treatment. Immunofluorescence-staining of tumor slices demonstrated that captopril significantly increased bradykinin expression, possibly explaining tumor perfusion improvements and endothelial gap enlargement. Additionally, imaging in vivo, imaging ex vivo and nanoparticle distribution in tumor slices indicated that after a single treatment with captopril, the accumulation of 115-nm nanoparticles in tumors had increased 2.81-fold with a more homogeneous distribution pattern in comparison to non-captopril treated controls. Finally, pharmacodynamics experiments demonstrated that captopril combined with paclitaxel-loaded nanoparticles resulted in the greatest tumor shrinkage and the most extensive necrosis in tumor tissues among all treatment groups. Taken together, the data from the present study suggest a novel strategy for improving tumor perfusion and enlarging blood vessel permeability simultaneously in order to improve

  9. Three-dimensional reconstruction of rat dermal blood vessels in vivo

    Science.gov (United States)

    Barton, Jennifer K.; Izatt, Joseph A.; Kulkarni, Manish D.; Welch, Ashley J.

    1997-05-01

    We performed imaging and reconstruction of dermal and subdermal blood vessels in a rat skin flap window model. The window model consists of a double thickness of dorsal skin which is sutured to a holding fixture. A 1 cm circle of skin is removed from one thickness, exposing the dermal blood vessels of the opposing side. An optical coherence tomography system operating at 1310 nm was used to image the blood vessels. A series of transverse images of the window model characterized sections of tissue. Off-the-shelf software for desktop and workstation computers was used to preprocess the images, identify and reconstruct blood vessels, and to extract parameters such depth, diameter, and percent volume of blood vessels. Such parameters may be of interest in developing improved treatments for vascular disorders such as port wine stains.

  10. Longitudinal forces acting at side-to-end and end-to-side anastomoses when a knitted polyester arterial prosthesis is implanted in the dog.

    Science.gov (United States)

    Dadgar, L; Downs, A R; Deng, X; Marois, Y; King, M W; Martin, L; Guidoin, R

    1995-01-01

    In a previous study, which investigated the tensions at the proximal and distal end-to-end anastomoses of a vascular prosthesis, no significant differences were found in the longitudinal forces between the two anastomotic sites after different periods of implantation. The present follow-up study was devised to study the longitudinal forces at a proximal side-to-end and a distal end-to-side anastomosis using a warp knitted polyester prosthesis implanted as a canine thorocoabdominal bypass. The external surface of the prosthesis contained a specially printed "tension indicator" design, which enabled changes in length to be assessed photographically at the two anastomoses at the time of implantation and at sacrifice. The longitudinal force at each site was then calculated using a relationship obtained experimentally between the total longitudinal force and the changes in length of the virgin graft in vitro. The in vitro measurements on the prosthesis were performed using a computer-controlled laser calibration system. Although the results showed a tendency toward a gradual loss in longitudinal force at both anastomoses over 7 months in situ, statistical analysis showed no significant difference in the longitudinal force at the two anastomotic sites after any period of implantation. Histopathological and textile analysis also showed that the characteristics of the prostheses were similar at both anastomotic sites. This does not mean, however, that the intramural stress concentrations experienced by the two sites were the same. While comparing the level of the longitudinal forces measured in this study with those observed in the previous thoracic aorta study using end-to-end anastomoses, no significant differences were observed due to the different types of anastomoses. It would appear that the longitudinal force is not one of the main etiological factors that cause the formation and localization of anastomotic failure.

  11. Biomechanical evaluation of the dynamic radioulnar convergence after ulnar head resection, two soft tissue stabilization methods of the distal ulna and ulnar head prosthesis implantation.

    Science.gov (United States)

    Sauerbier, Michael; Hahn, Michael E; Berglund, Lawrence J; An, Kai-Nan; Berger, Richard A

    2011-01-01

    The biomechanical performance of the Darrach procedure, its stabilizing methods and the effectiveness of an ulnar head prosthesis was evaluated in this experiment. The purpose of this study was to: (1) analyze the dynamic effects of the resection of the distal ulna on radioulnar convergence; and (2) evaluate the mechanical performance of two soft tissue stabilizing procedures (pronator quadratus advancement flap and ECU/FCU tenodesis) for the unstable distal ulnar stump and the implantation of an ulnar head prosthesis (uHead) following a distal ulnar resection (Darrach procedure) on radioulnar convergence. With a dynamic PC-controlled forearm simulator, cadaveric forearm rotation was actively and passively performed while simultaneously loading the relevant muscles. The resultant total forearm torque and the three-dimensional kinematics of the ulna, radius and third metacarpal were simultaneously recorded in seven fresh-frozen cadaver upper extremities. The resection of the distal ulna created an extreme instability of the forearm with movement of the radius toward the ulna (0.92-0.38 cm compared to the intact state) in each particular loading condition. The implantation of the ulnar head prosthesis effectively restored the stability of the DRUJ by simulating the geometry of the ulnar head. There were significantly better results after the implantation of the prosthesis compared with the Darrach and the soft tissue stabilization procedures. This study provides laboratory validity to the option of implanting an ulnar head endoprosthesis as an attempt to stabilize the distal forearm with instability after Darrach resection in lieu of performing soft tissue stabilization techniques.

  12. Comparison of blood loss between using non central part cutting knee prosthesis and distal central part cutting.

    Science.gov (United States)

    Malairungsakul, Anan

    2014-12-01

    Patients who undergo knee replacement surgery may need to receive a blood transfusion due to blood loss during the operation. Therefore it was important to improve the design of knee implant operative procedures in an attempt to reduce the rate of blood loss. The present study aimed to compare the blood loss between two types of knee replacement surgery. This is a retrospective study in which 78 patients received cemented knee replacements in Phayao Hospital between October 2010 and March 2012. There were two types of surgical procedure: 1) using an implant position covering the end of the femoral bone without cutting into the central part of the distal femoral, 2) using an implant position covering the end of the femoral bone cutting the central part of the distal femoral. Blood loss, blood transfusion, hemoglobin and hematocrit were recorded preoperatively, immediately postsurgery and 48 hours after surgery. Findings revealed that the knee replacement surgery using the implant position covering the end of the femoral bone without cutting the central part of the distal femoral significantly lowered the rate of blood loss when compared to using the implant position covering the end of the femoral bone with central cutting of the distal femor. The average blood loss during the operation without cutting at the central part of distal femoral was 49.50 ± 11.11 mL; whereas the operation cutting the central part of the distal femoral was 58.50 ± 11.69 mL. As regards blood loss, the knee replacement surgery using the implant position covering the end ofthefemoral bone without cutting the central part of distal femor was better than using the implant position covering the end of the femoral bone cutting at the central part of the distal femor.

  13. Combination of natural teeth and osseointegrated implants as prosthesis abutments in a posterior cantilever bridge

    Directory of Open Access Journals (Sweden)

    Michael Josef Kridanto Kamadjaja

    2008-06-01

    Full Text Available Dental implants have been used for several decades. Patients of all ages have chosen dental implants to replace a single tooth or several teeth or to support partial or full dentures. This paper reports two cases of patients treated with dental implant as alternative to replace the missing teeth and connected with natural tooth as abutments in a fixed restoration with distal cantilever bridge. The underlining reasons that we decided to make such kind fixed prostheses are because of clinically imposible to put the implant on certain area and the patients asked for prostheses as optimum as possible, so the mastication function could return to the homeostasis condition. The benefit of these treatments are that prostheses could be made as optimum as possible with a more economic price, so the patients feel quite satisfied. The result shows that a few years after the treatments finished there is no any disadvantageous effect of connecting teeth to implants as abutments in fixed partial dentures and there is no sign of a harmful effect to the opposing teeth either.

  14. Extraction of retinal tacks from subjects implanted with an epiretinal visual prosthesis.

    Science.gov (United States)

    de Juan, Eugene; Spencer, Rand; Barale, Pierre-Olivier; da Cruz, Lyndon; Neysmith, Jordan

    2013-10-01

    Retinal tacks, first developed for the treatment of complex retinal detachments, have more recently been used for the fixation of epiretinal electrode arrays as part of implanted visual prostheses. Here, we report on the clinical experience of extracting four such tacks after chronic implantation. The ability to safely extract retinal tacks ensures that epiretinal devices can be repositioned or removed if necessary. Custom-built, titanium alloy retinal tacks were mechanically removed from the posterior coats after prolonged implantation (up to 19 months). The resulting wound was characterized by clinical evaluation, fundus photography, and fluorescein angiography while being monitored for stability over time. The wounds were also compared to earlier published reports of the healing response around retinal tacks in human subjects. Tack extraction was accomplished successfully, without complication, in all four subjects. The wound site was readily identified by pale scar tissue. No change in the wound size or appearance was noted over many months of post-operative observation (up to 22 months after explant). No adverse effects on overall ocular health were detected. Extraction of retinal tacks from subjects implanted with epiretinal prostheses can be performed without significant complication. The long-term healing response appears to be stable and localized in eyes afflicted with retinitis pigmentosa or choroideremia. There was also minimal, if any, impact on the local circulatory system. These cases suggest that the use of retinal tacks for anchoring epiretinal visual prostheses does not preclude safe repositioning or removal of the device more than a year after implant.

  15. Effects of shear forces and pressure on blood vessel function and metabolism in a perfusion bioreactor.

    Science.gov (United States)

    Hoenicka, Markus; Wiedemann, Ludwig; Puehler, Thomas; Hirt, Stephan; Birnbaum, Dietrich E; Schmid, Christof

    2010-12-01

    Bovine saphenous veins (BSV) were incubated in a perfusion bioreactor to study vessel wall metabolism and wall structure under tissue engineering conditions. Group 1 vessels were perfused for 4 or 8 days. The viscosity of the medium was increased to that of blood in group 2. Group 3 vessels were additionally strained with luminal pressure. Groups 1-d through 3-d were similar except that BSV were endothelium-denuded before perfusion. Groups 1-a through 3-a used native vessels at elevated flow rates. Group 3 vessels responded significantly better to noradrenaline on day 4, whereas denuded vessels showed attenuated responses (p vessels. pO₂ gradients across the vessels were independent of time and significantly higher in group 2 (p vessels of groups 3, 1-d, and 3-d which released more lactate than glucose could supply (p vessels as well as all vessels perfused with elevated flow rates showed a loss of endothelial cells after 4 days, whereas group 2 and 3 vessels retained most of the endothelium. These data suggest that vessel metabolism was not limited by oxygen supply. Shear forces did not affect glucose metabolism but increased oxygen consumption and endothelial cell survival. Luminal pressure caused the utilization of energy sources other than glucose, as long as the endothelium was intact. Therefore, vessel metabolism needs to be monitored during tissue engineering procedures which challenge the constructs with mechanical stimuli.

  16. Primo Vascular System Accompanying a Blood Vessel from Tumor Tissue and a Method to Distinguish It from the Blood or the Lymph System

    Directory of Open Access Journals (Sweden)

    Jaekwan Lim

    2013-01-01

    Full Text Available A primo vessel was observed in the abdominal cavity in the lung cancer mouse model, and its function as an extra metastatic path was observed. In this work, we found a primo vessel accompanying a blood vessel emanating from a tumor in the skin. We also presented simple and efficient criteria to distinguish a primo vessel from a blood or a lymph vessel and from a nerve. The criteria for using DAPI and Phalloidin will be useful in clinical situations to find and identify the primo vessels among the blood vessels, lymph vessels, or nerves in the tissue surrounding a tumor such as a melanoma or breast cancer.

  17. Replacement of missing tooth in esthetic zone with implant-supported fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Mishra

    2017-01-01

    Full Text Available In the anterior region, the common reason for tooth loss is due to traumatic injury or congenital anomaly. Loss of a single tooth may cause functional and esthetic deficits to the patient. There are different treatment options available for replacing a missing incisor. Implant dentistry should be considered as first treatment alternative for replace a missing tooth. This case report presents the replacement of a missing maxillary left central incisor in a compromised site with dental implants along with bone graft followed by frenectomy to obtain a good clinical result and for better function and esthetics of the patient.

  18. An Alternative Technique for Fabrication of Frameworks in an Immediate Loading Implant Fixed Mandibular Prosthesis

    Directory of Open Access Journals (Sweden)

    André Gustavo Paleari

    2015-01-01

    Full Text Available The oral rehabilitation of edentulous patients with immediate loading has become a safe procedure with high predictability. The success is related to immediate fabrication of a passive fit framework to attach the implants. Based on these considerations, this case report shows an alternative technique for mandibular rehabilitation using implants immediately loaded, where the framework was fabricated using cylinders with internal reinforcement and precast pieces, electrowelding, and conventional welding providing esthetics and function to the patient in a short period of time.

  19. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...... masking of a vessel position and measurements of it's diameter from laser speckle images. This approach demonstrates high reliability and stability....

  20. Initial experience of two national centers in transcatheter aortic prosthesis implantation.

    Science.gov (United States)

    Lluberas, Sebastián; Abizaid, Alexandre; Siqueira, Dimytri; Ramos, Auristela; Costa, J Ribamar; Arrais, Magaly; Kambara, Antônio; Bihan, David Le; Sousa, Amanda; Sousa, J Eduardo

    2014-04-01

    Transcatheter aortic valve implantation is an effective alternative to surgical treatment of severe aortic stenosis in patients who are inoperable or at high surgical risk. To report the immediate and follow-up clinical and echocardiographic results of the initial experience of transcatheter aortic valve implantation. From 2009 June to 2013 February, 112 patients underwent transcatheter aortic valve implantation. Mean age was 82.5 ± 6.5 years, and the logistic EuroSCORE was 23.6 ± 13.5. Procedural success was 84%. After the intervention, a reduction in the mean systolic gradient was observed (pre: 54.7 ± 15.3 vs. post: 11.7 ± 4.0 mmHg; p < 0.01). Cerebrovascular accidents occurred in 3.6%, vascular complications in 19% and permanent pacemaker was required by 13% of the patients. Thirty-day mortality and at follow-up of 16 ± 11 months was 14% and 8.9% respectively. The presence of chronic obstructive pulmonary disease was the only predictor of mortality at 30 days and at follow-up. During follow up, aortic valve area and mean systolic gradient did not change significantly. Transcatheter aortic valve implantation is an effective and safe procedure for the treatment of aortic stenosis in high-surgical risk or inoperable patients. The presence of chronic obstructive pulmonary disease was the only independent predictor of mortality identified both in the first month post-intervention and at follow-up.

  1. Measuring Quality of Life in Stroke Subjects Receiving an Implanted Neural Prosthesis for Drop Foot

    NARCIS (Netherlands)

    Kottink, Anke I.; IJzerman, Maarten Joost; Hermens, Hermanus J.; Groothuis-Oudshoorn, Catharina Gerarda Maria; Kottink, A.I.R.

    2010-01-01

    The aim was to determine if the treatment of a drop foot by means of an implantable two-channel peroneal nerve stimulator improves health-related quality of life (HRQoL). All subjects were measured at baseline and after a follow-up period of 12 and 26 weeks. Twenty-nine stroke survivors with chronic

  2. Investigating laser/blood-vessel interaction with color Doppler optical coherence tomography

    Science.gov (United States)

    Barton, Jennifer K.; Izatt, Joseph A.; Welch, Ashley J.

    1998-04-01

    A non-invasive method of imaging laser irradiated blood vessels, and of tracking the healing response, has been achieved using Color Doppler Optical Coherence Tomography (CDOCT). This method may increase understanding of the mechanisms behind treatment of vascular disorders such as port wine stains. The CDOCT system uses a superluminescent diode with a center wavelength of 1280 nm. Pulsed dye and KTP lasers operating at 585 and 532 nm, respectively, were used to irradiate rat and hamster dorsal skin flap window models. The window model is a chronic preparation which exposes subdermal blood vessels while maintaining a thickness of normal skin. Irradiation sites were imaged with CDOCT prior to and immediately after laser irradiation, and at intervals up to several days following irradiation. The CDOCT signal was processed to provide both magnitude and color Doppler images. The Doppler signal provides an estimate of the blood flow velocity. The response of blood vessels to radiant exposures above and below the threshold for vessel coagulation was measured. An increase in the blood vessel backscattered signal was observed as blood and vessel walls were coagulated. Changes in blood flow velocity were noted in cases where vessels constricted or flow became occluded.

  3. Argus II retinal prosthesis implantation with scleral flap and autogenous temporalis fascia as alternative patch graft material: a 4-year follow-up.

    Science.gov (United States)

    Matet, Alexandre; Amar, Nawel; Mohand-Said, Saddek; Sahel, José-Alain; Barale, Pierre-Olivier

    2016-01-01

    The Argus II retinal prosthesis is composed of an epiretinal electrode array positioned over the macula and connected to an extrascleral electronics case via a silicone cable, running through a sclerotomy. During implantation, the manufacturer recommends to cover the sclerotomy site with a patch of processed human pericardium to prevent postoperative hypotony and conjunctival erosion by the underlying electronics case. Due to biomedical regulations prohibiting the use of this material in France, we developed an alternative technique combining a scleral flap protecting the sclerotomy and an autogenous graft of superior temporalis fascia overlying the electronics case. The purpose of this study is to describe the 4-year outcomes of this modified procedure in three subjects who underwent Argus II Retinal Prosthesis System implantation. Clinical data consisting of intraocular pressure measurements and tolerance in terms of conjunctival erosion or inflammation were retrospectively assessed over a 4-year postoperative follow-up. None of the three patients implanted with the modified technique developed ocular hypotony over 4 years. A normal, transient conjunctival inflammation occurred during the first postoperative month but conjunctival erosion was not observed in any of the three patients over 4 years. Four years after implantation, the autogenous temporalis fascia graft remained well tolerated and the retinal prosthesis was functional in all three patients. The combination of an autograft of superficial temporalis fascia and a scleral flap efficiently prevented leakage through the sclerotomy site, ocular hypotony, and conjunctival erosion by the extrascleral electronics case. This modified technique is suitable for the implantation of existing and forthcoming retinal prostheses. Superficial temporalis fascia may also be used as alternative to commercial tectonic tissues for scleral wound repair in clinical settings where they are not available.

  4. Pericyte coverage of abnormal blood vessels in myelofibrotic bone marrows

    DEFF Research Database (Denmark)

    Zetterberg, Eva; Vannucchi, Alessandro M; Migliaccio, Anna Rita

    2007-01-01

    BACKGROUND AND OBJECTIVES: Myelofibrotic bone marrow displays abnormal angiogenesis but the pathogenic mechanisms of this are poorly understood. Since pericyte abnormalities are described on solid tumor vessels we studied whether vessel morphology and pericyte coverage in bone marrow samples from...... megakaryocytopoesis, wide, pericyte-coated and morphologically aberrant vessels were detected. MVD was significantly greater in bone marrow and spleen samples from animals with myelofibrosis than in wild-type mice. INTERPRETATION AND CONCLUSIONS: We conclude that angiogenesis is similarly abnormal in human and murine...... myelofibrosis with intense pericyte coating, presumably related to abnormal megakaryocytopoiesis....

  5. Nerves are more abundant than blood vessels in the degenerate human intervertebral disc.

    Science.gov (United States)

    Binch, Abbie L A; Cole, Ashley A; Breakwell, Lee M; Michael, Antony L R; Chiverton, Neil; Creemers, Laura B; Cross, Alison K; Le Maitre, Christine L

    2015-12-21

    Chronic low back pain (LBP) is the most common cause of disability worldwide. New ideas surrounding LBP are emerging that are based on interactions between mechanical, biological and chemical influences on the human IVD. The degenerate IVD is proposed to be innervated by sensory nerve fibres and vascularised by blood vessels, and it is speculated to contribute to pain sensation. However, the incidence of nerve and blood vessel ingrowth, as well as whether these features are always associated, is unknown. We investigated the presence of nerves and blood vessels in the nucleus pulposus (NP) of the IVD in a large population of human discs. Immunohistochemistry was performed with 61 human IVD samples, to identify and localise nerves (neurofilament 200 [NF200]/protein gene product 9.5) and blood vessels (CD31) within different regions of the IVD. Immunopositivity for NF200 was identified within all regions of the IVD within post-mortem tissues. Nerves were seen to protrude across lamellar ridges and through matrix towards NP cells. Nerves were identified deep within the NP and were in many cases, but not always, seen in close proximity to fissures or in areas where decreased matrix was seen. Fifteen percent of samples were degenerate and negative for nerves and blood vessels, whilst 16 % of all samples were degenerate with nerves and blood vessels. We identified 52% of samples that were degenerate with nerves but no blood vessels. Interestingly, only 4% of all samples were degenerate with no nerves but positive for blood vessels. Of the 85 samples investigated, only 6 % of samples were non-degenerate without nerves and blood vessels and 7% had nerves but no blood vessels. This study addresses the controversial topic of nerve and blood vessel ingrowth into the IVD in a large number of human samples. Our findings demonstrate that nerves are present within a large proportion of NP samples from degenerate IVDs. This study shows a possible link between nerve ingrowth and

  6. Venous Ligation: A Novel Strategy for Glans Enhancement in Penile Prosthesis Implantation

    Directory of Open Access Journals (Sweden)

    Geng-Long Hsu

    2014-01-01

    Full Text Available Although penile implantation remains a final solution for patients with refractory impotence, undesirable postoperative effects, including penile size reduction and cold sensation of the glans penis, remain problematic. We report results of a surgical method designed to avoid these problems. From 2003 to 2013, 35 consecutive patients received a malleable penile implant. Of these, 15 men (the enhancing group were also treated with venous ligation of the retrocoronal venous plexus, deep dorsal vein, and cavernosal veins. The remaining 20 men formed the control group, treated with only a penile implant. Follow-up ranged from 1.1 to 10.0 years, with an average of 6.7 ± 1.5 years. Although preoperative glanular dimension did not differ significantly between the two groups, significant respective difference at one day and one year postoperatively was found in the glanular circumference (128.8 ± 6.8 mm versus 115.3 ± 7.2 mm and 130.6 ± 7.2 mm versus 100.5 ± 7.3 mm; both P<0.05, radius (38.8 ± 2.7 mm versus 37.1 ± 2.8 mm and 41.5 ± 2.6 mm versus 33.8 ± 2.9 mm; latter P<0.01, and satisfaction rate (91.7% versus 53.3%, P<0.01 as well. Based on our results, selective venous ligation appears to enhance the glans penis dimension in implant patients.

  7. Development of a multichannel vestibular prosthesis prototype by modification of a commercially available cochlear implant.

    Science.gov (United States)

    Valentin, Nicolas S; Hageman, Kristin N; Dai, Chenkai; Della Santina, Charles C; Fridman, Gene Y

    2013-09-01

    No adequate treatment exists for individuals who remain disabled by bilateral loss of vestibular (inner ear inertial) sensation despite rehabilitation. We have restored vestibular reflexes using lab-built multichannel vestibular prostheses (MVPs) in animals, but translation to clinical practice may be best accomplished by modification of a commercially available cochlear implant (CI). In this interim report, we describe preliminary efforts toward that goal. We developed software and circuitry to sense head rotation and drive a CI's implanted stimulator (IS) to deliver up to 1 K pulses/s via nine electrodes implanted near vestibular nerve branches. Studies in two rhesus monkeys using the modified CI revealed in vivo performance similar to our existing dedicated MVPs. A key focus of our study was the head-worn unit (HWU), which magnetically couples across the scalp to the IS. The HWU must remain securely fixed to the skull to faithfully sense head motion and maintain continuous stimulation. We measured normal and shear force thresholds at which HWU-IS decoupling occurred as a function of scalp thickness and calculated pressure exerted on the scalp. The HWU remained attached for human scalp thicknesses from 3-7.8 mm for forces experienced during routine daily activities, while pressure on the scalp remained below capillary perfusion pressure.

  8. Development of a Multichannel Vestibular Prosthesis Prototype by Modification of a Commercially Available Cochlear Implant

    Science.gov (United States)

    Valentin, Nicolas S.; Hageman, Kristin; Dai, Chenkai; Santina, Charles C. Della; Fridman, Gene Y.

    2014-01-01

    No adequate treatment exists for individuals who remain disabled by bilateral loss of vestibular (inner ear inertial) sensation despite rehabilitation. We have restored vestibular reflexes using lab-built multichannel vestibular prostheses (MVPs) in animals, but translation to clinical practice may be best accomplished by modification of a commercially available cochlear implant (CI). We developed software and circuitry to sense head rotation and drive a CI's implanted stimulator (IS) to deliver up to 1Kpulses/s via 9 electrodes implanted near vestibular nerve branches. Studies in two rhesus monkeys using the modified CI (MCI) revealed in vivo performance similar to our existing dedicated MVPs. Like commercially available CIs, our design uses an external head-worn unit (HWU) that is magnetically coupled across the scalp to the IS. The HWU must remain securely fixed to the skull to faithfully sense head motion with gyroscopes and maintain continuous stimulation. We measured normal and shear force thresholds at which HWU-IS decoupling occurred as a function of scalp thickness and calculated pressure exerted on the scalp. The HWU remained attached across the human scalp thicknesses from 3mm to 7.8mm for forces experienced during routine daily activities, with magnets exerting pressure on the scalp that remains below capillary perfusion pressure. PMID:23649285

  9. [Application of attached gingiva reconstruction in implant-supported dental prosthesis].

    Science.gov (United States)

    Li, Peng; Jiang, Bao-qi; Lan, Jing; Huang, Hai-yun; Liang, Jin; Ma, Xiao-ni; Xu, Xin

    2013-04-01

    To explore a method of attached gingiva reconstruction around dental implants and to evaluate its clinical outcomes and technical characters. From January 2011 to August 2011, a total of 10 implants were included in this study from 8 patients who had inadequate attached gingiva and needed to undergo secondary operation. A modified apically positioned flap technique was applied to reconstruct attached gingiva at the time of secondary operation. Crown restoration was finished 4 weeks after the operation and the patients were recalled 6 months after restoration. Effective keratinized mucosal width was recorded separately before the operation, 4 weeks after the operation and 6 months after restoration. Clinical examination was conducted 6 months after restoration including modified plaque index(mPI), probing depth(PD), bleeding index(BI) and percentage of bleeding on probing. Statistical analysis was performed using Wilcoxon signed rank test with SPSS18.0 software package. Four weeks after the operation, there was an average increase of 2.41 mm in effective keratinized mucosal width compared with the preoperative value (Pgingiva around implants can be effectively reconstructed. The short-term effects are satisfactory.

  10. Solitonlike attractor for blood vessel tip density in angiogenesis

    Science.gov (United States)

    Bonilla, L. L.; Carretero, M.; Terragni, F.

    2016-12-01

    Recently, numerical simulations of a stochastic model have shown that the density of vessel tips in tumor-induced angiogenesis adopts a solitonlike profile [Sci. Rep. 6, 31296 (2016), 10.1038/srep31296]. In this work, we derive and solve the equations for the soliton collective coordinates that indicate how the soliton adapts its shape and velocity to varying chemotaxis and diffusion. The vessel tip density can be reconstructed from the soliton formulas. While the stochastic model exhibits large fluctuations, we show that the location of the maximum vessel tip density for different replicas follows closely the soliton peak position calculated either by ensemble averages or by solving an alternative deterministic description of the density. The simple soliton collective coordinate equations may also be used to ascertain the response of the vessel network to changes in the parameters and thus to control it.

  11. The role of prosthetic abutment material on the stress distribution in a maxillary single implant-supported fixed prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Hugo Eduardo, E-mail: hugo.e.peixoto@hotmail.com [Implantology Team, Latin American Institute of Research and Education in Dentistry, Curitiba, Paraná (Brazil); Bordin, Dimorvan, E-mail: dimorvan_bordin@hotmail.com [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Del Bel Cury, Altair A., E-mail: altcury@fop.unicamp.br [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Silva, Wander José da, E-mail: wanderjose@fop.unicamp.br [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Faot, Fernanda, E-mail: fernanda.faot@gmail.com [Department of Restorative Dentistry, School of Dentistry, Federal University of Pelotas, Gonçalves Chaves, 457, 2nd floor, Pelotas, Rio Grande do Sul 96015-560 (Brazil)

    2016-08-01

    Purpose: Evaluate the influence of abutment's material and geometry on stress distribution in a single implant-supported prosthesis. Materials and Methods: Three-dimensional models were made based on tomographic slices of the upper middle incisor area, in which a morse taper implant was positioned and a titanium (Ti) or zirconia (ZrN) universal abutments was installed. The commercially available geometry of titanium (T) and zirconia (Z) abutments were used to draw two models, TM1 and ZM1 respectively, which served as control groups. These models were compared with 2 experimental groups were the mechanical properties of Z were applied to the titanium abutment (TM2) and vice versa for the zirconia abutment (ZM2). Subsequently, loading was simulated in two steps, starting with a preload phase, calculated with the respective friction coefficients of each materials, followed by a combined preload and chewing force. The maximum von Mises stress was described. Data were analyzed by two-way ANOVA that considered material composition, geometry and loading (p < 0.05). Results: Titanium and zirconia abutments showed similar von Mises stresses in the mechanical part of the four models. The area with the highest concentration of stress was the screw thread, following by the screw body. The highest stress levels occurred in screw thread was observed during the preloading phase in the ZM1 model (931 MPa); and during the combined loading in the TM1 model (965 MPa). Statistically significant differences were observed for loading, the material × loading interaction, and the loading × geometry interaction (p < 0.05). Preloading contributed for 77.89% of the stress (p < 0.05). There were no statistically significant differences to the other factors (p > 0.05). Conclusion: The screw was the piece most intensely affected, mainly through the preload force, independent of the abutment's material. - Highlights: • The abutment's screw was the most impaired piece of the

  12. A functional requirement for astroglia in promoting blood vessel development in the early postnatal brain.

    Science.gov (United States)

    Ma, Shang; Kwon, Hyo Jun; Huang, Zhen

    2012-01-01

    Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in promoting angiogenesis throughout the central nervous system. To determine the roles that astrocytes may play during brain angiogenesis, we employ genetic approaches to inhibit astrogliogenesis during perinatal corticogenesis and examine its effects on brain vessel development. We find that conditional deletion from glial progenitors of orc3, a gene required for DNA replication, dramatically reduces glial progenitor cell number in the subventricular zone and astrocytes in the early postnatal cerebral cortex. This, in turn, results in severe reductions in both the density and branching frequency of cortical blood vessels. Consistent with a delayed growth but not regression of vessels, we find neither significant net decreases in vessel density between different stages after normalizing for cortical expansion nor obvious apoptosis of endothelial cells in these mutants. Furthermore, concomitant with loss of astroglial interactions, we find increased endothelial cell proliferation, enlarged vessel luminal size as well as enhanced cytoskeletal gene expression in pericytes, which suggests compensatory changes in vascular cells. Lastly, we find that blood vessel morphology in mutant cortices recovers substantially at later stages, following astrogliosis. These results thus implicate a functional requirement for astroglia in promoting blood vessel growth during brain development.

  13. High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

    Science.gov (United States)

    Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

    2011-03-01

    Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

  14. Distortion of CAD-CAM-fabricated implant-fixed titanium and zirconia complete dental prosthesis frameworks.

    Science.gov (United States)

    Al-Meraikhi, Hadi; Yilmaz, Burak; McGlumphy, Edwin; Brantley, William A; Johnston, William M

    2018-01-01

    Computer-aided design and computer-aided manufacturing (CAD-CAM)-fabricated titanium and zirconia implant-supported fixed dental prostheses have become increasingly popular for restoring patients with complete edentulism. However, the distortion level of these frameworks is not well known. The purpose of this in vitro study was to compare the 3-dimensional (3D) distortion of CAD-CAM zirconia and titanium implant-fixed screw-retained complete dental prostheses. A master edentulous model with 4 implants at the positions of the maxillary first molars and canines was used. Multiunit abutments (Nobel Biocare) secured to the model were digitally scanned using scan bodies and a laboratory scanner (S600 ARTI; Zirkonzahn). Titanium (n=5) and zirconia (n=5) frameworks were milled using a CAD-CAM system (Zirkonzahn M1; Zirkonzahn). All frameworks were scanned using an industrial computed tomography (CT) scanner (Nikon/X-Tek XT H 225kV MCT Micro-Focus). The direct CT scans were reconstructed to generate standard tessellation language (STL) files. To calculate the 3D distortion of the frameworks, STL files of the CT scans were aligned to the CAD model using a sum of the least squares best-fit algorithm. Surface comparison points were placed on the CAD model on the midfacial aspect of all teeth. The 3D distortion of each direct scan to the CAD model was calculated. In addition, color maps of the scan-to-CAD comparison were constructed using a ±0.500 mm color scale range. Both materials exhibited distortion; however, no significant difference was found in the amount of distortion from the CAD model between the materials (P=.747). Absolute values of deviations from the CAD model were evident in the x and y plane and less so in the z direction. Zirconia and titanium frameworks showed similar 3D distortion compared with the CAD model for the tested CAD-CAM and implant systems. The distortion was more pronounced in the horizontal and sagittal plane than in the vertical plane

  15. Roentgenologic aspects of acute respiratory in sufficiency after heart valve prosthesis implantation

    International Nuclear Information System (INIS)

    Pchelin, I.G.; Ishchenko, B.I.

    1993-01-01

    Analysis of the X-ray findings in 156 patients with acute respiratory insufficiency (ART) in the immediate periods after implantation of heart valve prostheses has shown that various pulmonary complications, such as pulmonary edema (in 84% of cases), atelectasis, hypoventilation (5.1%), hemothorax (6.4%), pneumothorax (0.6%) were the prerequisites for the development of respiratory disorders. Pneumonias were not the primary cause of ART but an additional factor for the respiratory disorder progress, for they develop in the presence of previous pulmonary changes. The necessity and possibility of establishing the pathogenetic mechanism of pulmonary edema is shown

  16. Transcatheter implantation of a new prototype of self-expanding aortic valve prosthesis: first experience

    Directory of Open Access Journals (Sweden)

    Е. И. Кретов

    2016-12-01

    Full Text Available Calcific aortic stenosis is an aortic valve disease of atherosclerotic origin occurring in 2-4 % of persons older than 65 years, for whom open surgery is contraindicated. Models of self-expanding aortic valves available today have a number of significant drawbacks. The authors have developed a prototype of a new aortic valve and present its first successful implantation in the experiment.Received 17 October 2016. Accepted 22 November 2016.Funding: The study had no sponsorship.Conflict of interest: The authors declare no conflict of interest.

  17. Peptide-Mediated Liposomal Drug Delivery System Targeting Tumor Blood Vessels in Anticancer Therapy

    Directory of Open Access Journals (Sweden)

    Han-Chung Wu

    2010-01-01

    Full Text Available Solid tumors are known to recruit new blood vessels to support their growth. Therefore, unique molecules expressed on tumor endothelial cells can function as targets for the antiangiogenic therapy of cancer. Current efforts are focusing on developing therapeutic agents capable of specifically targeting cancer cells and tumor-associated microenvironments including tumor blood vessels. These therapies hold the promise of high efficacy and low toxicity. One recognized strategy for improving the therapeutic effectiveness of conventional chemotherapeutics is to encapsulate anticancer drugs into targeting liposomes that bind to the cell surface receptors expressed on tumor-associated endothelial cells. These anti-angiogenic drug delivery systems could be used to target both tumor blood vessels as well as the tumor cells, themselves. This article reviews the mechanisms and advantages of various present and potential methods using peptide-conjugated liposomes to specifically destroy tumor blood vessels in anticancer therapy.

  18. Blood vessel growth blocker may treat AIDS-related Kaposi’s sarcoma

    Science.gov (United States)

    Patients with an AIDS-associated cancer, Kaposi's sarcoma (KS), showed improvement after receiving the combination of bevacizumab, a cancer drug that blocks the growth of new blood vessels, and highly active antiretroviral therapy (HAART).

  19. Effect of electrical stimulation on blood flow velocity and vessel size

    Directory of Open Access Journals (Sweden)

    Jin Hee-Kyung

    2017-03-01

    Full Text Available Interferential current electrical stimulation alters blood flow velocity and vessel size. We aimed to investigate the changes in the autonomic nervous system depending on electrical stimulation parameters.

  20. Engineering a Blood Vessel Network Module for Body-on-a-Chip Applications.

    Science.gov (United States)

    Ryu, Hyunryul; Oh, Soojung; Lee, Hyun Jae; Lee, Jin Young; Lee, Hae Kwang; Jeon, Noo Li

    2015-06-01

    The blood circulatory system links all organs from one to another to support and maintain each organ's functions consistently. Therefore, blood vessels have been considered as a vital unit. Engineering perfusable functional blood vessels in vitro has been challenging due to difficulties in designing the connection between rigid macroscale tubes and fragile microscale ones. Here, we propose a generalizable method to engineer a "long" perfusable blood vessel network. To form millimeter-scale vessels, fibroblasts were co-cultured with human umbilical vein endothelial cells (HUVECs) in close proximity. In contrast to previous works, in which all cells were permanently placed within the device, we developed a novel method to culture paracrine factor secreting fibroblasts on an O-ring-shaped guide that can be transferred in and out. This approach affords flexibility in co-culture, where the effects of secreted factors can be decoupled. Using this, blood vessels with length up to 2 mm were successfully produced in a reproducible manner (>90%). Because the vessels form a perfusable network within the channel, simple links to inlets and outlets of the device allowed connections to the outside world. The robust and reproducible formation of in vitro engineered vessels can be used as a module to link various organ components as parts of future body-on-a-chip applications. © 2014 Society for Laboratory Automation and Screening.

  1. Cardiac Resynchronization Therapy Device Implantation in a Patient with Congenitally Corrected Transposition of Great Vessels

    Directory of Open Access Journals (Sweden)

    Reza Mollazadeh

    2017-03-01

    Full Text Available A 29-year-old woman was referred to our hospital due to exacerbation in dyspnea on exertion and easy fatigability. A known case of congenitally corrected transposition of the great vessels and congenital complete heart block, she had already received a permanent single-chamber pacemaker. Decision was made to implant a biventricular pacemaker for the treatment of the failing heart. Excellent coronary sinus lead implantation was done, conferring amelioration of symptoms, QRS narrowing in the electrocardiogram, and improvement of systemic ventricular systolic function in echocardiography. Over a 15-month follow-up period, she had no dyspnea on exertion. This case highlights the significance of upgrading pacemakers in patients with heart failure.

  2. Prefabrication of a vascularized nerve graft by vessel implantation: preliminary report of an experimental model.

    Science.gov (United States)

    Cavadas, P C; Vera-Sempere, F J

    1994-01-01

    Regeneration through vascularized nerve grafts (VNG) seems to be better than nonvascularized nerve grafts (NVNG), especially in hostile beds. We report on an experimental technique of prefabrication of VNG by direct vessel implantation. An arteriovenous fistula was created in the groin region with autologous vein grafts in the Wistar rat model, and implanted into the sciatic nerve. Five weeks later the sciatic VNG was elevated on the prefabricated pedicle. The flap was free-transferred orthotopically over a silicone sheet to impede plasmatic imbibition. Flap viability at 3 days was complete. India ink injection of the AV fistula resulted in capillary ink filling within the nerve and surrounding tissues. Histologic sections of the flap were examined, revealing its neovascularity. In an ongoing study, the regeneration through this prefabricated VNG is being compared to native VNG.

  3. Temperature evolution in tissues embedded with large blood vessels during photo-thermal heating.

    Science.gov (United States)

    Paul, Anup; Narasimhan, Arunn; Kahlen, Franz J; Das, Sarit K

    2014-04-01

    During laser-assisted photo-thermal therapy, the temperature of the heated tissue region must rise to the therapeutic value (e.g., 43°C) for complete ablation of the target cells. Large blood vessels (larger than 500 micron in diameter) at or near the irradiated tissues have a considerable impact on the transient temperature distribution in the tissue. In this study, the cooling effects of large blood vessels on temperature distribution in tissues during laser irradiation are predicted using finite element based simulation. A uniform flow is assumed at the entrance and three-dimensional conjugate heat transfer equations in the tissue region and the blood region are simultaneously solved for different vascular models. A volumetric heat source term based on Beer-Lambert law is introduced into the energy equation to account for laser heating. The heating pattern is taken to depend on the absorption and scattering coefficients of the tissue medium. Experiments are also conducted on tissue mimics in the presence and absence of simulated blood vessels to validate the numerical model. The coupled heat transfer between thermally significant blood vessels and their surrounding tissue for three different tissue-vascular networks are analyzed keeping the laser irradiation constant. A surface temperature map is obtained for different vascular models and for the bare tissue (without blood vessels). The transient temperature distribution is seen to differ according to the nature of the vascular network, blood vessel size, flow rate, laser spot size, laser power and tissue blood perfusion rate. The simulations suggest that the blood flow through large blood vessels in the vicinity of the photothermally heated tissue can lead to inefficient heating of the target. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Development and evaluation of in vivo tissue engineered blood vessels in a porcine model.

    Science.gov (United States)

    Rothuizen, Tonia C; Damanik, Febriyani F R; Lavrijsen, Tom; Visser, Michel J T; Hamming, Jaap F; Lalai, Reshma A; Duijs, Jacques M G J; van Zonneveld, Anton Jan; Hoefer, Imo E; van Blitterswijk, Clemens A; Rabelink, T J; Moroni, Lorenzo; Rotmans, Joris I

    2016-01-01

    There's a large clinical need for novel vascular grafts. Tissue engineered blood vessels (TEBVs) have great potential to improve the outcome of vascular grafting procedures. Here, we present a novel approach to generate autologous TEBV in vivo. Polymer rods were engineered and implanted, evoking an inflammatory response that culminates in encapsulation by a fibrocellular capsule. We hypothesized that, after extrusion of the rod, the fibrocellular capsule differentiates into an adequate vascular conduit once grafted into the vasculature. Rods were implanted subcutaneously in pigs. After 4 weeks, rods with tissue capsules grown around it were harvested. Tissue capsules were grafted bilaterally as carotid artery interposition. One and 4-week patency were evaluated by angiography whereupon pigs were sacrificed. Tissue capsules before and after grafting were evaluated on tissue remodeling using immunohistochemistry, RNA profiling and mechanical testing. Rods were encapsulated by thick, well-vascularized tissue capsules, composed of circumferentially aligned fibroblasts, collagen and few leukocytes, with adequate mechanical strength. Patency was 100% after 1 week and 87.5% after 4 weeks. After grafting, tissue capsules remodeled towards a vascular phenotype. Gene profiles of TEBVs gained more similarity with carotid artery. Wall thickness and αSMA-positive area significantly increased. Interestingly, a substantial portion of (myo)fibroblasts present before grafting expressed smooth muscle cell markers. While leukocytes were hardly present anymore, the lumen was largely covered with endothelial cells. Burst pressure remained stable after grafting. Autologous TEBVs were created in vivo with sufficient mechanical strength enabling vascular grafting. Grafts differentiated towards a vascular phenotype upon grafting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Superficial and deep blood vessel distribution in the frog telencephalon. Reference to morphological brain asymmetries.

    Science.gov (United States)

    Kemali, M; Sada, E; Fiorino, L

    1990-01-01

    Nine frogs of the species "Rana esculenta" were heart perfused with Microfile Silicone Rubber. The frogs were examined both after dissection (cut with a razor blade) to study the superficial blood vessel pattern, and histologically (the Nissl staining method) to study the distribution of the deep blood capillaries. While the superficial blood vary in pattern, the deep capillaries are distributed symmetrically. This finding does not support a correlation between blood vessel pattern and morphological brain asymmetry, at least in the frog, and thus other explanations must be sought to explain brain asymmetry.

  6. Using a fixed provisional prosthesis during post-extraction healing and implant placement.

    Science.gov (United States)

    McArdle, Barry F

    2006-03-01

    Most dental patients insist on the use of provisional prostheses throughout healing and osseointegration when replacing extracted teeth with implants in esthetically sensitive areas. Removable appliances of some kind are normally used for this purpose, but patients often consider them to be too cumbersome. This can lead to decreased case acceptance and compliance with the use of the provisional restoration, which can compromise the final result of treatment. Custom fixed solutions to this problem exist, but they tend to be more complicated, less practical, and more expensive than other options now available. The Monodont bridge, a new system of prefabricated components for the creation of provisional fixed partial dentures, can be more esthetic, more retentive, more functional, more cost-effective, and more universally applicable than any other available techniques. This can raise patient tolerance of provisional prostheses and thus increase case acceptance, while fostering a more predictable esthetic result with regard to soft tissue contours and emergence profile.

  7. Differential Effects between Cigarette Total Particulate Matter and Cigarette Smoke Extract on Blood and Blood Vessel

    Science.gov (United States)

    Park, Jung-Min; Chang, Kyung-Hwa; Park, Kwang-Hoon; Choi, Seong-Jin; Lee, Kyuhong; Lee, Jin-Yong; Satoh, Masahiko; Song, Seong-Yu; Lee, Moo-Yeol

    2016-01-01

    The generation and collection of cigarette smoke (CS) is a prerequisite for any toxicology study on smoking, especially an in vitro CS exposure study. In this study, the effects on blood and vascular function were tested with two widely used CS preparations to compare the biological effects of CS with respect to the CS preparation used. CS was prepared in the form of total particulate matter (TPM), which is CS trapped in a Cambridge filter pad, and cigarette smoke extract (CSE), which is CS trapped in phosphate-buffered saline. TPM potentiated platelet reactivity to thrombin and thus increased aggregation at a concentration of 25~100 μg/mL, whereas 2.5~10% CSE decreased platelet aggregation by thrombin. Both TPM and CSE inhibited vascular contraction by phenylephrine at 50~100 μg/mL and 10%, respectively. TPM inhibited acetylcholine-induced vasorelaxation at 10~100 μg/mL, but CSE exhibited a minimal effect on relaxation at the concentration that affects vasoconstriction. Neither TPM nor CSE induced hemolysis of erythrocytes or influenced plasma coagulation, as assessed by prothrombin time (PT) and activated partial thromboplastin time (aPTT). Taken together, CS affects platelet activity and deteriorates vasomotor functions in vitro. However, the effect on blood and blood vessels may vary depending on the CS preparation. Therefore, the results of experiments conducted with CS preparations should be interpreted with caution. PMID:27818738

  8. Short-term follow-up of masticatory adaptation after rehabilitation with an immediately loaded implant-supported prosthesis: a pilot assessment.

    Science.gov (United States)

    Tanaka, Mihoko; Bruno, Collaert; Jacobs, Reinhilde; Torisu, Tetsurou; Murata, Hiroshi

    2017-12-01

    When teeth are extracted, sensory function is decreased by a loss of periodontal ligament receptions. When replacing teeth by oral implants, one hopes to restore the sensory feedback pathway as such to allow for physiological implant integration and optimized oral function with implant-supported prostheses. What remains to be investigated is how to adapt to different oral rehabilitations. The purpose of this pilot study was to assess four aspects of masticatory adaptation after rehabilitation with an immediately loaded implant-supported prosthesis and to observe how each aspect will recover respectively. Eight participants with complete dentures were enrolled. They received an implant-supported acrylic resin provisional bridge, 1 day after implant surgery. Masticatory adaptation was examined by assessing occlusal contact, approximate maximum bite force, masticatory efficiency of gum-like specimens, and food hardness perception. Occlusal contact and approximate maximum bite force were significantly increased 3 months after implant rehabilitation, with the bite force gradually building up to a 72% increase compared to baseline. Masticatory efficiency increased by 46% immediately after surgery, stabilizing at around 40% 3 months after implant rehabilitation. Hardness perception also improved, with a reduction of the error rate by 16% over time. This assessment demonstrated masticatory adaptation immediately after implant rehabilitation with improvements noted up to 3 months after surgery and rehabilitation. It was also observed that, despite gradually improved bite force in all patients, masticatory efficiency and food hardness perception did not necessarily follow this tendency. The findings in this pilot may also be used to assess adaptation of oral function after implant rehabilitation by studying the combined outcome of four tests (occlusal contact, maximum bite force, masticatory efficiency, and food hardness perception).

  9. Segmentation of retinal blood vessels using artificial neural networks for early detection of diabetic retinopathy

    Science.gov (United States)

    Mann, Kulwinder S.; Kaur, Sukhpreet

    2017-06-01

    There are various eye diseases in the patients suffering from the diabetes which includes Diabetic Retinopathy, Glaucoma, Hypertension etc. These all are the most common sight threatening eye diseases due to the changes in the blood vessel structure. The proposed method using supervised methods concluded that the segmentation of the retinal blood vessels can be performed accurately using neural networks training. It uses features which include Gray level features; Moment Invariant based features, Gabor filtering, Intensity feature, Vesselness feature for feature vector computation. Then the feature vector is calculated using only the prominent features.

  10. Aortic valve replacement and prosthesis-patient mismatch in the era of trans-catheter aortic valve implantation.

    Science.gov (United States)

    Morita, Shigeki

    2016-08-01

    The treatment strategy for aortic stenosis (AS) has been changing due to newly developed valvular prostheses and trans-catheter aortic valve implantation (TAVI). To determine the role of new modalities for AS with a small aortic root, papers using the concept of prosthesis-patient mismatch (PPM) were reviewed. First, to determine the cut-off value of the indexed effective orifice area (IEOA) for defining PPM, the studies of surgical aortic valve replacement (SAVR) with a follow-up longer than 5 years and a patient number larger than 500 were reviewed. Second, the papers comparing TAVI and SAVR were reviewed. Furthermore, the prevalence of PPM was reviewed, with the addition of papers on aortic root enlargement, sutureless AVR, and aortic valve reconstruction with autologous pericardium. The results of the long-term survival after aortic valve replacement (AVR) have indicated that an IEOA less than 0.65 cm(2)/m(2) should be avoided in all cases, whereas the indications for patients with an IEOA between 065 and 0.85 cm(2)/m(2) should be determined by considering multiple factors. A large body size and younger age have a significantly negative influence on the long-term survival. In Asian population, the prevalence of PPM was low, despite the fact that the size of the aortic annulus was small. The IEOA after TAVI was larger than after surgical AVR in population-matched studies. To evaluate the role of TAVI and other modalities for a small aortic root, studies with a longer follow-up and larger volume are thus warranted.

  11. Remission spectrometry for blood vessel detection during stereotactic biopsy of brain tumors.

    Science.gov (United States)

    Markwardt, Niklas A; Stepp, Herbert; Franz, Gerhard; Sroka, Ronald; Goetz, Marcus; Zelenkov, Petr; Rühm, Adrian

    2017-08-01

    Stereotactic biopsy is used to enable diagnostic confirmation of brain tumors and treatment planning. Despite being a well-established technique, it is related to significant morbidity and mortality rates mostly caused by hemorrhages due to blood vessel ruptures. This paper presents a method of vessel detection during stereotactic biopsy that can be easily implemented by integrating two side-view fibers into a conventional side-cutting biopsy needle. Tissue within the needle window is illuminated through the first fiber; the second fiber detects the remitted light. By taking the ratio of the intensities at two wavelengths with strongly differing hemoglobin absorption, blood vessels can be recognized immediately before biopsy sampling. Via ray tracing simulations and phantom experiments, the dependency of the remission ratio R = I 578 /I 650 on various parameters (blood oxygenation, fiber-to-vessel and inter-fiber distance, vessel diameter and orientation) was investigated for a bare-fiber probe. Up to 800-1200 µm away from the probe, a vessel can be recognized by a considerable reduction of the remission ratio from the background level. The technique was also successfully tested with a real biopsy needle probe on both optical phantoms and ex-vivo porcine brain tissue, thus showing potential to improve the safety of stereotactic biopsy. Dual-wavelength remission measurement for the detection of blood vessels during stereotactic biopsy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Growth and Remodeling in Blood Vessels Studied In Vivo With Fractal Analysis

    Science.gov (United States)

    Parsons-Wingerter, Patricia A.

    2003-01-01

    Every cell in the human body must reside in close proximity to a blood vessel (within approximately 200 mm) because blood vessels provide the oxygen, metabolite, and fluid exchanges required for cellular existence. The growth and remodeling of blood vessels are required to support the normal physiology of embryonic development, reproductive biology, wound healing and adaptive remodeling to exercise, as well as abnormal tissue change in diseases such as cancer, diabetes, and coronary heart disease. Cardiovascular and hemodynamic (blood flow dynamics) alterations experienced by astronauts during long-term spaceflight, including orthostatic intolerance, fluid shifts in the body, and reduced numbers of red (erythrocyte) and white (immune) blood cells, are identified as risk factors of very high priority in the NASA task force report on risk reduction for human spaceflight, the "Critical Path Roadmap."

  13. Effect of the Blood Vessel Viscoelasticity on Periodic Blood Pressure Wave Propagation

    Science.gov (United States)

    Kitawaki, Tomoki; Shimizu, Masashi

    Clinical arterial stiffness indexes such as PWV (pulse wave velocity) or PP (pulse pressure), which are obtained by analyzing blood pressure pulse waveforms in vivo, are used in the prognosis of cardiovascular diseases and thus analyses of pulse waveform are clinically important. The pulse wave in vivo, however, is complicated because of the complex viscoelastic property of the blood vessel wall. In addition, numerical flow simulations are useful for understanding pulse wave propagation in circulatory systems. Our proposed nonlinear one-dimensional numerical simulation model can accurately simulate the measurements of pressure waves in a silicone rubber tube and indicate that the viscoelasticity of the tube wall was significantly influenced by a single pulse waveform; however, the influence of viscoelasticity change on periodic pulsatile wave propagation has not yet been studied. The purpose of this study was therefore to investigate the effect of viscoelasticity change on the periodic pulsatile wave. For this purpose, we examined the effect of the viscoelasticity of a single silicone tube on periodic pulse wave propagation by comparing the calculated results using a one-dimensional model. As a result, the one-dimensional model could accurately express the experimental results with periodic pulsatile waves. In addition, both PWV and PP increase when the viscoelastic value of the dynamic modulus elasticity ratio increases, because increasing the elastic modulus is more effective than the energy dissipation effect by viscoelasticity change. Consequently, it is necessary to measure the viscoelastic property of the vessel wall accurately in order to estimate the arterial stiffness index (PWV and PP) accurately.

  14. Implante transapical de valva aórtica: resultados de uma nova prótese brasileira Transapical aortic valve implantation: results of a brazilian prosthesis

    Directory of Open Access Journals (Sweden)

    Diego Felipe Gaia

    2010-09-01

    procedimento alternativo.OBJECTIVE: The aortic valve replacement is a routine procedure with acceptable risk, but in some cases, such a risk can justify contraindication. The minimally invasive transcatheter aortic valve implantation has been viable, with lower morbidity and mortality. The aim of this study was to develop a national catheter-mounted aortic bioprosthesis for the aortic position implant. METHODS: After animal studies, 14 patients with high EuroSCORE underwent transcatheter aortic valve implantation. Median Logistic EuroSCORE was 43.7%. Four patients presented with dysfunctional bioprosthesis, remaining ones presented calcified aortic stenosis. All patients presented symptoms. Procedures were performed in a hybrid OR under fluoroscopic and echocardiography guidance. Using a left minithoracotomy the prosthesis was implanted through the ventricular apex under ventricular pacing or hemorrhagic shock, after aortic valvoplasty. Echocardiograph and angiograph controls were performed, and the patients were referred to ICU. RESULTS: Implant was feasible in 13 cases. There were no intra-operative deaths. Median peak transvalvular aortic gradient reduced to 25.0 mmHg, and left ventricular function improved in the first seven post-operative days. Paravalvular aortic regurgitation was mild and present in 71%. No definitive pacemaker was needed. There was no peripheral vascular complication. Overall mortality was 42%. CONCLUSION: The transapical implantation of cathetermounted bioprosthesis was a feasible procedure. Long term follow-up is mandatory in order to access efficacy and indications.

  15. Endoscope-Assisted and Controlled Argus II Epiretinal Prosthesis Implantation in Late-Stage Retinitis Pigmentosa: A Report of 2 Cases.

    Science.gov (United States)

    Özmert, Emin; Demirel, Sibel

    2016-01-01

    Several different approaches for restoring sight in subjects who are blind due to outer retinal degeneration are currently under investigation, including stem cell therapy, gene therapy, and visual prostheses. Although many different types of visual prostheses have shown promise, to date, the Argus II Epiretinal Prosthesis System, developed in a clinical setting over the course of 10 years, is the world's first and only retinal prosthesis that has been approved by the United States Food and Drug Administration (FDA) and has been given the CE-Mark for sale within the European Economic Area (EEA). The incidence of serious adverse events from Argus II implantation decreased over time after minor changes in the implant design and improvements in the surgical steps used for the procedure had been made. In order to further decrease the scleral incision-related complications and enhance the assessment of the tack position and the contact between the array and the inner macular surface, we used an ophthalmic endoscope during the regular course of Argus II implantation surgery in 2 patients with late-stage retinitis pigmentosa in an attempt to improve the anatomical and functional outcomes.

  16. Endoscope-Assisted and Controlled Argus II Epiretinal Prosthesis Implantation in Late-Stage Retinitis Pigmentosa: A Report of 2 Cases

    Directory of Open Access Journals (Sweden)

    Emin Özmert

    2016-12-01

    Full Text Available Several different approaches for restoring sight in subjects who are blind due to outer retinal degeneration are currently under investigation, including stem cell therapy, gene therapy, and visual prostheses. Although many different types of visual prostheses have shown promise, to date, the Argus II Epiretinal Prosthesis System, developed in a clinical setting over the course of 10 years, is the world’s first and only retinal prosthesis that has been approved by the United States Food and Drug Administration (FDA and has been given the CE-Mark for sale within the European Economic Area (EEA. The incidence of serious adverse events from Argus II implantation decreased over time after minor changes in the implant design and improvements in the surgical steps used for the procedure had been made. In order to further decrease the scleral incision-related complications and enhance the assessment of the tack position and the contact between the array and the inner macular surface, we used an ophthalmic endoscope during the regular course of Argus II implantation surgery in 2 patients with late-stage retinitis pigmentosa in an attempt to improve the anatomical and functional outcomes.

  17. Laser photothermolysis of single blood vessels in the chick chorioallantoic membrane (CAM)

    Science.gov (United States)

    Kimel, Sol; Svaasand, Lars O.; Milner, Thomas E.; Hammer-Wilson, Marie J.; Schell, Michael J.; Nelson, J. Stuart; Berns, Michael W.

    1994-02-01

    Individual blood vessels in the chick chorioallantoic membrane (CAM) were selectively coagulated through photothermolysis, using pulsed laser irradiation at 585 nm. Pulse durations were chosen to be 0.45 ms and 10 ms, which correspond to the thermal relaxation times in blood vessels of 30 micrometers and 150 micrometers diameter, respectively. The dose vs diameter (D vs d) relationship for coagulation was calculated for the two pulse shapes. The energy deposited in a cylindrical absorber of diameter d by an optical field, incident perpendicular to the vessel, was expressed analytically and compared with the energy required to coagulate a blood vessel of the same lumen diameter. When thermal diffusion is incorporated into the model, our findings can be accounted for quantitatively. This information will be of use for improving the laser treatment of port wine stains and other vasculopathies.

  18. Conduit vessel blood flow during the trek to Mount Everest base camp.

    Science.gov (United States)

    Dumais, Valerie; Nault, Patrice; Tsertsvadze, Alexander; Forbes, Thomas L

    2011-12-01

    Hemodynamic changes in response to the hypoxic environment of high altitude are vascular bed-specific. The aim of the present study was to investigate diameter and blood flow changes in conduit vessels in response to hypobaric hypoxia. Eleven healthy subjects ascending Mount Everest to base camp participated in this study. Vessel diameter and blood velocity for brachial, carotid, common femoral, superficial femoral, and deep femoral arteries were measured by portable Doppler ultrasound. Blood flow was calculated from these values. Measurements were taken at sea level, at increasing altitudes on ascent to base camp (1310 m, 3470 m, 5330 m), and repeated on descent to lower altitude (1310 m). For all vessels except carotids, both vessel diameter and blood flow decreased between sea level and initial ascent to altitude, with subsequent persistence of these decreased values; there was no further significant change with continued ascent to higher altitude. Blood flow for all arteries (except carotids) increased significantly on descent to lower altitude, with an associated nonsignificant increase in velocity and decrease in diameter. This study showed that there is vasoconstriction of limb conduit vessels at altitude, which persists upon descent to lower altitude. Blood flow in these vessels also decreases with initial exposure to high altitude, yet increases when returning to lower altitude, reflecting variations in blood velocity. Carotid arteries responded differently to the stimulus of hypobaria than limb conduit vessels; there was no change in diameter seen on ascent or descent, but there was a progressive decrease in blood flow on ascent, with no change on subsequent descent. Copyright © 2011 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  19. A prospective dual-energy X-ray absorptiometry study of bone remodeling after implantation of the Nanos short-stemmed prosthesis.

    Science.gov (United States)

    Zeh, Alexander; Pankow, Franziska; Röllinhoff, Marc; Delank, Stefan; Wohlrab, David

    2013-04-01

    The aim of this study was to analyze the bone remodeling around the Nanos stem (Smith & Nephew, Marl, Germany) after primary total hip arthroplasty for coxarthrosis. In 25 patients (15 male, 10 female, mean age 59.9 years) with the diagnosis of coxarthrosis, a DEXA scan was performed immediately after surgery, 97 days (SD 6.1 days) and 368 days (SD 6.2 days) after implantation of a Nanos prosthesis. Plain radiographs were analyzed digitally for radiolucent lines, varus-valgus femoral stem alignment, measurement of stem migration and changes in varus-valgus femoral stem alignment. The position of the center of rotation (COR) and the offset were assessed pre- and postoperatively. Harris Hip Score was used to evaluate the clinical outcome. The DEXA scan showed a significant and relevant increase in BMD (Bone Mineral Density) in Gruen-Zone 6 (12%) and a decrease in Zone 1 (15%), 2 (5%) and 7 (12%), which was interpreted as reflecting a distal load transfer in the metaphysis of the femur. There was no clinically relevant migration or tilting of the Nanos stem. Radiolucent lines were noted in 12 cases, mainly at the polished tip area of the prosthesis; this was not regarded as a sign of impaired osseointegration. There was no significant difference between the position of the COR and the pre- and postoperative offset. The absence of stem migration, angulation, or relevant radiolucent lines is seen as evidence for an unimpaired osseointegration of the Nanos stem approximately 12 months after implantation. It is concluded that the Nanos prosthesis can reduce loss of BMD of the proximal femur composed with conventional stems or other short-stemmed implants.

  20. Ultrastructural characterization of soft tissues surrounding implanted hip prosthesis by complementary PIXE and TEM methods

    Science.gov (United States)

    Jallot, E.; Benhayoune, H.; Kilian, L.; Balossier, G.; Bonhomme, P.; Oudadesse, H.; Irigaray, J. L.

    We study soft tissues surrounding hip prostheses from three different patients. We evaluate the elemental composition of different fragments. The tissues are examined by means of two complementary methods in such analysis: Particle Induced X-ray Emission (PIXE) and Scanning Transmission Electron Microscopy (STEM) coupled with X-ray microanalysis (Energy Dispersive X-ray, EDX). These methods allow to determine locally at `macro' and `micro' level the chemistry of soft tissues. The findings confirmed the presence of metal in soft tissue near the three different hips. The tissues' composition undergoes important modifications with a systematic elevation of trace metal in patients with failed implants. We observe a corrosion which causes the continual release of particles into the tissues. Corrosion alters the shape size and chemical composition of wear particles embedded in soft tissue around the failed hip. EDX analysis showed that the wear particles contained varying quantities of titanium and aluminium. This phenomenon may be related with the variation of time of contact with soft tissues for each particle and Ti solubility.

  1. An experimental system for the study of ultrasound exposure of isolated blood vessels

    International Nuclear Information System (INIS)

    Tokarczyk, Anna; Rivens, Ian; Symonds-Tayler, Richard; Ter Haar, Gail; Van Bavel, E

    2013-01-01

    An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels. (paper)

  2. An experimental system for the study of ultrasound exposure of isolated blood vessels

    Science.gov (United States)

    Tokarczyk, Anna; Rivens, Ian; van Bavel, E.; Symonds-Tayler, Richard; ter Haar, Gail

    2013-04-01

    An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels.

  3. Blood pressure gradients in cerebral arteries: a clue to pathogenesis of cerebral small vessel disease.

    Science.gov (United States)

    Blanco, Pablo J; Müller, Lucas O; Spence, J David

    2017-09-01

    The role of hypertension in cerebral small vessel disease is poorly understood. At the base of the brain (the 'vascular centrencephalon'), short straight arteries transmit blood pressure directly to small resistance vessels; the cerebral convexity is supplied by long arteries with many branches, resulting in a drop in blood pressure. Hypertensive small vessel disease (lipohyalinosis) causes the classically described lacunar infarctions at the base of the brain; however, periventricular white matter intensities (WMIs) seen on MRI and WMI in subcortical areas over the convexity, which are often also called 'lacunes', probably have different aetiologies. We studied pressure gradients from proximal to distal regions of the cerebral vasculature by mathematical modelling. Blood flow/pressure equations were solved in an Anatomically Detailed Arterial Network (ADAN) model, considering a normotensive and a hypertensive case. Model parameters were suitably modified to account for structural changes in arterial vessels in the hypertensive scenario. Computations predict a marked drop in blood pressure from large and medium-sized cerebral vessels to cerebral peripheral beds. When blood pressure in the brachial artery is 192/113 mm Hg, the pressure in the small arterioles of the posterior parietal artery bed would be only 117/68 mm Hg. In the normotensive case, with blood pressure in the brachial artery of 117/75 mm Hg, the pressure in small parietal arterioles would be only 59/38 mm Hg. These findings have important implications for understanding small vessel disease. The marked pressure gradient across cerebral arteries should be taken into account when evaluating the pathogenesis of small WMIs on MRI. Hypertensive small vessel disease, affecting the arterioles at the base of the brain should be distinguished from small vessel disease in subcortical regions of the convexity and venous disease in the periventricular white matter.

  4. Outcome and serum ion determination up to 11 years after implantation of a cemented metal-on-metal hip prosthesis.

    Science.gov (United States)

    Lazennec, Jean-Yves; Boyer, Patrick; Poupon, Joel; Rousseau, Marc-Antoine; Roy, Carine; Ravaud, Philippe; Catonné, Yves

    2009-04-01

    Little is known about the long-term outcome of cemented metal-on-metal hip arthroplasties. We evaluated a consecutive series of metal-on-metal polyethylene-backed cemented hip arthroplasties implanted in patients under 60 years of age. 109 patients (134 joint replacements) were followed prospectively for mean 9 (7-11) years. The evaluation included clinical score, radiographic assessment, and blood sampling for ion level determination. At the final review, 12 hips had been revised, mainly because of aseptic loosening of the socket. Using revision for aseptic loosening as the endpoint, the survival rate at 9 years was 91% for the cup and 99% for the stem. In addition, 35 hips showed radiolucent lines at the bone-cement interface of the acetabulum and some were associated with osteolysis. The median serum cobalt and chromium levels were relatively constant over time, and were much higher than the detection level throughout the study period. The cobalt level was 1.5 microg/L 1 year after implantation, and 1.44 microg/L 9 years after implantation. Revisions for aseptic loosening and radiographic findings in the sockets led us to halt metal-on-metal-backed polyethylene cemented hip arthroplasty procedures. If the rigidity of the cemented socket is a reason for loosening, excessive release of metal ions and particles may be involved. Further investigations are required to confirm this hypothesis and to determine whether subluxation, microseparation, and hypersensitivity also play a role.

  5. A rigid disc for protection of exposed blood vessels during negative pressure wound therapy.

    Science.gov (United States)

    Anesäter, Erik; Borgquist, Ola; Torbrand, Christian; Roupé, K Markus; Ingemansson, Richard; Lindstedt, Sandra; Malmsjö, Malin

    2013-02-01

    There are increasing reports of serious complications and deaths associated with negative pressure wound therapy (NPWT). Bleeding may occur when NPWT is applied to a wound with exposed blood vessels. Inserting a rigid disc in the wound may protect these structures. The authors examined the effects of rigid discs on wound bed tissue pressure and blood flow through a large blood vessel in the wound bed during NPWT. Wounds were created over the femoral artery in the groin of 8 pigs. Rigid discs were inserted. Wound bed pressures and arterial blood flow were measured during NPWT. Pressure transduction to the wound bed was similar for control wounds and wounds with discs. Blood flow through the femoral artery decreased in control wounds. When a disc was inserted, the blood flow was restored. NPWT causes hypoperfusion in the wound bed tissue, presumably as a result of mechanical deformation. The insertion of a rigid barrier alleviates this effect and restores blood flow.

  6. Transfemoral transcatheter aortic valve implantation in patients with small diseased peripheral vessels

    Energy Technology Data Exchange (ETDEWEB)

    Ruparelia, Neil [San Raffaele Scientific Institute, Milan (Italy); Imperial College, London (United Kingdom); Buzzatti, Nicola; Romano, Vittorio; Longoni, Matteo; Figini, Fillipo; Montorfano, Matteo; Kawamoto, Hiroyoshi; Miyazaki, Tadashi; Spagnolo, Pietro; Alfieri, Ottavio; Colombo, Antonio [San Raffaele Scientific Institute, Milan (Italy); Latib, Azeem, E-mail: info@emocolumbus.it [San Raffaele Scientific Institute, Milan (Italy)

    2015-09-15

    Objectives: The aim of this study was to assess the feasibility, safety and short-term outcomes of transfemoral transcatheter aortic valve implantation (TF-TAVI) in patients with small diseased peripheral vessels. Background: The transfemoral (TF) route for transcatheter aortic valve (TAVI) is the default option due to associated advantages. However, this is limited due to the high prevalence of significant peripheral arterial disease and increased risk of vascular complications. Methods: Of 539 consecutive patients undergoing TAVI in a single Italian center, 23 patients underwent TF-TAVI in the presence of small peripheral vessels as defined by a minimal luminal diameter (MLD) of ≤ 5.5 mm [by computed tomography (CT)] and/or the inability to advance a large-bore sheath. Calcification was defined as being concentric if calcium extended more than 270° around the circumference of the artery. All patients underwent 30-day clinical follow-up. Results: 17 (73.9%) patients underwent peripheral vessel pre-dilatation with a semi-compliant balloon and 6 (26.1%) patients with a Solopath sheath. 6 (26.1%) patients suffered a peri-procedural complication, with 1 patient requiring surgical embolectomy for thrombotic occlusion and the remaining patients successfully managed percutaneously in the catheter laboratory. No patient suffered a vessel perforation or required implantation of a covered stent. At 30-day follow-up, all patients were free of symptoms and signs or symptoms of peripheral vascular disease, with well-functioning TAVI prostheses as evaluated by echocardiography. Conclusions: Performing TF-TAVI is feasible in patients with no other viable vascular access option in the presence of small MLD and calcification of the peripheral vasculature, with any anticipated acute vascular complication managed in the catheter laboratory with established percutaneous techniques. - Highlights: • Small peripheral vessels is regarded as contraindication to transfemoral TAVI.

  7. Vasodilator effects of ibudilast on retinal blood vessels in anesthetized rats.

    Science.gov (United States)

    Noguchi, Masahiro; Mori, Asami; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2009-11-01

    Ibudilast (3-isobutyryl-2-isopropylpyrazolo[1,5-alpha]pyridine) is clinically used as a cerebral vasodilator in Japan. However, the effects of ibudilast on retinal blood vessels have not been fully examined. The aim of this study, therefore, was to examine the effects of ibudilast on retinal blood vessels in rats in vivo. Male Wistar rats (8 to 10 weeks old) were anesthetized with thiobutabarbital (120 mg/kg, intraperitoneally (i.p.)). Retinal vascular images were captured with a fundus camera system for small animals, and the diameter of retinal blood vessels was measured. Ibudilast (0.1 and 1 mg/kg, intravenously (i.v.)) elicited a sustained increase in the diameter of retinal blood vessels and heart rate without altering systemic blood pressure. The effects of ibudilast were significantly reduced by treatment with the nonselective cyclooxygenase inhibitor indomethacin (5 mg/kg, i.p.). These results suggest that ibudilast dilates retinal blood vessels through cyclooxygenase-dependent mechanisms in rats in vivo.

  8. Simplified procedure for the immediate loading of a complete fixed prosthesis supported by four implants in the maxillary jaw: a 2-year prospective study.

    Science.gov (United States)

    Piano, Sergio; Romeo, Eugenio; Sbricoli, Luca; Pisoni, Gianluca; Cea, Niccoló; Lops, Diego

    2016-12-01

    The aim of this study was to verify the reliability of a system for the fixed retention of complete maxillary prostheses supported by four implants with a follow-up of 2 years. Patients were treated between September 2009 and December 2010 with four Straumann Bone Level SLActive implants supporting a complete prosthesis (CPs). The two distal implants were positioned mesially to the maxillary sinus and with a mesio-distal inclination ≤ 30° in order to reduce the distal prosthesis cantilever. An immediate loading surgical protocol was used. The CPs were planned to be fixed to multibase abutments to test their retention for a fixed rehabilitation. Clinical and radiographic parameters as probing pocket depth (PPD), bleeding score (mBI), plaque index (PI), and marginal bone loss (MBL) were assessed at a 1- and 2-year follow-up visits. Moreover, any biological and prosthodontic maintenance events were recorded. Clinical and radiographic parameters changes were analyzed. Twenty-one patients treated with a total of 84 implants completed the 2-year examination period. Four patients were lost to follow up. No technical complication was recorded. Also, no implant, reconstruction, or abutment failures were observed. Therefore, an implant and prosthetic survival rate of 100% were achieved after 2 years. The mean periodontal parameter scores after 2 years of function were 2.6 mm for PPD (SD 0.8 mm), 0.3 for mBI (SD 0.5 mm), and 1.2 for PI (SD 0.4 mm) indexes, respectively. In addition, the mean MBL score measured at the 2-year follow-up visit was -0.34 mm (SD of -0.45 mm). Furthermore, no peri-implant soft tissue inflammation or peri-implant infection was observed. It has been shown that immediate loading of four implants positioned anteriorly to the maxillary sinus could be a reliable treatment procedure to support fixed complete restorations. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrabi

    2012-01-01

    Full Text Available This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is governed by the continuity equation and the Navier-Stokes equations. In this study, the stenosis shape is cosine by using Tu and Devil model. Comparing the results obtained from three stenosed vessels with 30%, 50%, and 75% area severity, we find that higher percent-area severity of stenosis leads to higher extrapressure jumps and higher blood speeds around the stenosis site. Also, we observe that the size of the stenosis in stenosed vessels does influence the blood flow. A little change on the cross-sectional value makes vast change on the blood flow rate. This simulation helps the people working in the field of physiological fluid dynamics as well as the medical practitioners.

  10. Study of fluid dynamics reveals direct communications between lymphatic vessels and venous blood vessels at lymph nodes of mice.

    Science.gov (United States)

    Takeda, Kazu; Mori, Shiro; Kodama, Tetsuya

    2017-06-01

    Cancer cells metastasize to lymph nodes, with distant metastasis resulting in poor prognosis. The role of lymph node metastasis (LNM) in the spread of cancer to distant organs remain incompletely characterized. The visualization of flow dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice, which develop systemic swelling of lymph nodes up to 10mm in diameter, has revealed that lymph nodes have the potential to be a direct source of systemic metastasis. However, it is not known whether these fluid dynamics characteristics are universal phenomena present in other strains of laboratory mice. Here we show that the fluid dynamics observed in MXH10/Mo-lpr/lpr mice are the same as those observed in C57BL/6J, BALB/cAJcl and NOD/ShiJic-scidJcl mice. Furthermore, when fluorescent solution was injected into a tumor-bearing lymph node, the flow dynamics observed in the efferent lymphatic vessels and thoracoepigastric vein depended on the type of tumor cell. Our results indicate that fluid dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice are generalized phenomena seen in conventional laboratory mice. We anticipate our results can facilitate studies of the progression of lymphatic metastasis to hematogenous metastasis via lymph nodes and the early diagnosis and treatment of LNM. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Ionic implantation by plasma in titanium and stainless steels used in prosthesis and medical instruments

    International Nuclear Information System (INIS)

    Munoz C, A. E.

    2008-01-01

    A study of a process known as plasma immersion ion implantation (PIII) of nitrogen at low voltages (< 4 kV) into three kind of samples: 1) austenitic stainless AISI 316-L steel plates, 2) ferritic stainless AISI 434 steel-based dentistry drills and 3) commercially pure titanium (CPTi) disks. On the case of CPTi the study was conducted in nitrogen- oxygen calibrated mixtures: 90% N-10% O, 80% N-20% O, 70% N-30% O and in 99.5% pure oxygen and 99.9% pure nitrogen. The PIII process was carried out by using a direct current plasma source controlled both in voltage and current, a negative voltage pulse modulator, a stainless AISI 304 steel vacuum chamber and a rod of the same material, horizontally located in the upper region of the chamber, which plays the role of anode in the plasma discharge. The purpose of the nitriding is forming a relatively thick layer on the surface of the steel specimens in order to enhance their both microhardness and general corrosion performances, desirable in medical applications. This layer contains interstitial nitrogen atoms (∼24% at.) which gives place to a deformed lattice (expanded phase) of the steel. Vickers microhardness and potentiodynamic tests (the latter in agreement to the norm ASTM G-61-89) confirm an increase of microhardness up to three times and a decrease of general corrosion rate in one order of magnitude. The nitriding of de dentistry drills is aimed at inhibiting the pitting corrosion produced by the asepsis process which results in pit nucleations, their propagation and consequent fractures when being under cyclic stress (fatigue). Scanning electron microscope micrographs reveal the risks involved in surpassing the critical treatment simple temperature of 450 C as the PIII process itself induces pitting. On its part, cyclic (ASTM G-61) potentiodynamic tests indicate an excellent pitting corrosion resistance of the samples treated under 450 C. In turn, the treatment of CPTi was meant to develop oxidized and

  12. 21 CFR 878.3590 - Ear prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear prosthesis. 878.3590 Section 878.3590 Food and... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis is a silicone rubber solid device intended to be implanted to reconstruct the external...

  13. 21 CFR 876.3750 - Testicular prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Testicular prosthesis. 876.3750 Section 876.3750...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Prosthetic Devices § 876.3750 Testicular prosthesis. (a) Identification. A testicular prosthesis is an implanted device that consists of a solid or gel-filled silicone...

  14. 21 CFR 878.3550 - Chin prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Chin prosthesis. 878.3550 Section 878.3550 Food... DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3550 Chin prosthesis. (a) Identification. A chin prosthesis is a silicone rubber solid device intended to be implanted to augment or...

  15. 21 CFR 878.3680 - Nose prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nose prosthesis. 878.3680 Section 878.3680 Food... DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3680 Nose prosthesis. (a) Identification. A nose prosthesis is a silicone rubber solid device intended to be implanted to augment or...

  16. Rehabilitation of an edentulous cleft lip and palate patient with a soft palate defect using a bar-retained, implant-supported speech-aid prosthesis: a clinical report.

    Science.gov (United States)

    Hakan Tuna, S; Pekkan, Gurel; Buyukgural, Bulent

    2009-01-01

    Prosthetic rehabilitation of an edentulous cleft lip and palate patient with a combined hard and soft palate defect is a great challenge, due to the lack of retention of the obturator prosthesis as a result of its weight and the inability to obtain a border seal. Dental implants improve the retention, stability, and occlusal function of prostheses when used in carefully selected cleft lip and palate cases. This clinical report presents an edentulous unilateral cleft lip and palate patient who has hard and soft palate defects and an atrophied maxilla, treated with an implant-supported speech-aid prosthesis.

  17. Role of toll-like receptor 4 in the inflammation reaction surrounding silicone prosthesis.

    Science.gov (United States)

    Auquit-Auckbur, Isabelle; Caillot, Frédérique; Arnoult, Christophe; Menard, Jean-François; Drouot, Laurent; Courville, Philippe; Tron, François; Musette, Philippe

    2011-05-01

    The inflammation which occurs around the silicone prosthesis is a complex process that can provoke the failure of the device and compromise the health of the implanted patient. Toll-like receptors (TLRs), which are transmembrane proteins, are now known to act in the innate immune response and in endogenous inflammation. The aim of our study was to assess the role of TLR4 in the foreign body reaction to a silicone shell prosthesis. Disks of shell silicone prosthesis were implanted in the subcutaneous tissue of C57BL6-TLR4-/- and C57BL6-WT mice. At day 14, inflammatory cell infiltrate and vessel sections around the prosthesis were less numerous in TLR4-/- than in WT mice. A histomorphometric analysis showed that the capsule around the implant was 1.96-fold less thick in depleted TLR4 than in wild-type mice. In addition, vascular endothelial growth factor and transforming growth factor 1 were underexpressed in the surrounding tissue of the prosthesis in TLR4-/- mice. Our study suggests, from this foreign body response model against silicone in mice, that TLR4 plays a key role in the reaction process around silicone implants. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  18. One-piece zirconia oral implants: one-year results from a prospective case series. 2. Three-unit fixed dental prosthesis (FDP) reconstruction.

    Science.gov (United States)

    Kohal, Ralf-Joachim; Patzelt, Sebastian B M; Butz, Frank; Sahlin, Herman

    2013-05-01

    To evaluate the clinical and radiological outcome of one-piece zirconia oral implants for three-unit fixed dental prosthesis (FDP) replacement after 1 year. Twenty eight patients were recruited for the investigation and signed an informed consent. All patients were treated with a one-stage implant surgery and a three-unit immediate temporary restoration on two one-piece zirconia implants. The implants were fabricated of yttria-stabilized tetragonal zirconia (y-TZP). The endosseous part of the implants was tapered with a porous surface. A total of 56 implants were inserted in the 28 patients. A total of 12 implants were placed in the upper jaws (six in the anterior area and six in the posterior area) and 44 in mandibles (all in the posterior area). At implant insertion and after 1 year, standardized radiographs were taken to evaluate the peri-implant bone loss. To evaluate any influences from different baseline parameters on the marginal bone loss a univariate analysis was performed. Clinical soft tissue parameters probing depth (PD), clinical attachment level (CAL), modified bleeding index (mBI) and modified plaque index (mPI) were recorded. Implant cumulative survival rates were calculated using actuarial life table analysis. Changes in the clinical variables were assessed using the Wilcoxon Signed Ranks test (PD, CAL) and the Sign test (mBl, mPl). All significance tests were conducted at a 5% level of significance. After 1 year, one implant was lost resulting in a survival rate of 98.2%. The patient was excluded from further analysis. The marginal bone loss after 1 year amounted to 1.95 mm. In 40% of the patients a bone loss of at least 2 mm and in 28% of the patients a loss of more than 3 mm were observed. The PD decreased for implant and tooth sites over time, the values being significantly higher for implants than for teeth. Over 1 year, the CAL increased slightly around the implants and decreased around the teeth. At the 1-year follow-up, the CAL at

  19. Perivascular adipose tissue alleviates inflammatory factors and stenosis in diabetic blood vessels.

    Science.gov (United States)

    Li, Tianjia; Liu, Xinnong; Ni, Leng; Wang, Zhanqi; Wang, Wenda; Shi, Tao; Liu, Xiu; Liu, Changwei

    2016-11-11

    Adipose tissue can modulate disease processes in a depot-specific manner. However, the functional properties of perivascular adipocytes, and their influence on the pathophysiology of blood vessel walls, remain to be determined. In this study, we aimed to investigate whether perivascular adipose tissue could have an ameliorative effect on blood vessels damaged in diabetes. Using in vitro coculture, and in vivo transplantation model simulating diabetic angioplasty-induced injury, we showed that perivascular adipose tissue has an important function in protecting blood vessels from high glucose impairment. Levels of inflammatory cytokines, including intercellular cell adhesion molecule-1 and osteopontin, were markedly reduced, whereas that of endothelial nitric-oxide synthase was markedly elevated in vascular walls. These depot-specific differences in blood vessels exposed to high levels of glucose were demonstrable both in vivo, with transplanted adipose tissues, and in vitro, when vascular endothelial cells were cocultured with adipocytes. In addition, intimal hyperplasia was also decreased by transplanted perivascular adipose tissue after balloon injury combined with hyperglycemia. We conclude that perivascular adipocytes can reduce inflammation in blood vessels and promote the normal function of endothelium, which could afford a new therapeutic strategy in vascular walls damaged by diabetes. Copyright © 2016. Published by Elsevier Inc.

  20. Nitric oxide dilates rat retinal blood vessels by cyclooxygenase-dependent mechanisms.

    Science.gov (United States)

    Ogawa, Naoto; Mori, Asami; Hasebe, Masami; Hoshino, Maya; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2009-10-01

    It has been suggested that nitric oxide (NO) stimulates the cyclooxygenase (COX)-dependent mechanisms in the ocular vasculature; however, the importance of the pathway in regulating retinal circulation in vivo remains to be elucidated. Therefore, we investigated the role of COX-dependent mechanisms in NO-induced vasodilation of retinal blood vessels in thiobutabarbital-anesthetized rats with and without neuronal blockade (tetrodotoxin treatment). Fundus images were captured with a digital camera that was equipped with a special objective lens. The retinal vascular response was assessed by measuring changes in diameter of the retinal blood vessel. The localization of COX and soluble guanylyl cyclase in rat retina was examined using immunohistochemistry. The NO donors (sodium nitroprusside and NOR3) increased the diameter of the retinal blood vessels but decreased systemic blood pressure in a dose-dependent manner. Treatment of rats with indomethacin, a nonselective COX inhibitor, or SC-560, a selective COX-1 inhibitor, markedly attenuated the vasodilation of retinal arterioles, but not the depressor response, to the NO donors. However, both the vascular responses to NO donors were unaffected by the selective COX-2 inhibitors NS-398 and nimesulide. Indomethacin did not change the retinal vascular and depressor responses to hydralazine, 8-(4-chlorophenylthio)-guanosine-3', 5'-cyclic monophosphate (a membrane-permeable cGMP analog) and 8-(4-chlorophenylthio)-adenosine-3', 5'-cyclic monophosphate (a membrane-permeable cAMP analog). Treatment with SQ 22536, an adenylyl cyclase inhibitor, but not ODQ, a soluble guanylyl cyclase inhibitor, significantly attenuated the NOR3-induced vasodilation of retinal arterioles. The COX-1 immunoreactivity was found in retinal blood vessels. The retinal blood vessel was faintly stained for soluble guanylyl cyclase, although the apparent immunoreactivities on mesenteric and choroidal blood vessels were observed. These results suggest

  1. Truncated Hormone Inhibits Breast Tumor Blood Vessel Formation, Not Tumor Growth | Center for Cancer Research

    Science.gov (United States)

    The hormone prolactin (PRL) plays a critical role in normal breast development by stimulating the proliferation of mammary cells, the production of milk proteins, and the formation of new mammary blood vessels. Unfortunately, the same cell and vessel growth pathways controlled by PRL in normal cells also operate in breast cancer cells, and elevated plasma PRL is a risk factor for breast cancer, especially in post-menopausal women.

  2. Estimation Of Blood Vessels Functional State By Means Of Analysis Of Temperature Reaction On Occlusive Test

    Directory of Open Access Journals (Sweden)

    A.P. Rytik

    2009-12-01

    Full Text Available Temperature reaction of distant phalanges in the case of the occlusive test has been registered. It has been revealed that the temperature reaction on the occlusive test for the group of patients with disturbances of vessel tone regulation differs from the reaction of norm group. Possible influence of vessel regulation state and volumetric blood supply on the skin temperature dynamics has been estimated. Diagnostic ability of the temperature occlusive test has been investigated

  3. Estimation Of Blood Vessels Functional State By Means Of Analysis Of Temperature Reaction On Occlusive Test

    OpenAIRE

    A.P. Rytik; E.V. Miroshnichenko; A.A. Sagaidachnyi; A.V. Skripal; A.A. Protopopov; D.A. Usanov

    2009-01-01

    Temperature reaction of distant phalanges in the case of the occlusive test has been registered. It has been revealed that the temperature reaction on the occlusive test for the group of patients with disturbances of vessel tone regulation differs from the reaction of norm group. Possible influence of vessel regulation state and volumetric blood supply on the skin temperature dynamics has been estimated. Diagnostic ability of the temperature occlusive test has been investigated

  4. 2-year follow-up of patients undergoing transcatheter aortic valve implantation using a self-expanding valve prosthesis.

    Science.gov (United States)

    Buellesfeld, Lutz; Gerckens, Ulrich; Schuler, Gerhard; Bonan, Raoul; Kovac, Jan; Serruys, Patrick W; Labinaz, Marino; den Heijer, Peter; Mullen, Michael; Tymchak, Wayne; Windecker, Stephan; Mueller, Ralf; Grube, Eberhard

    2011-04-19

    The purpose of this study was to evaluate the safety, device performance, and clinical outcome up to 2 years for patients undergoing transcatheter aortic valve implantation (TAVI). The role of TAVI in the treatment of calcific aortic stenosis evolves rapidly, but mid- and long-term results are scarce. We conducted a prospective, multicenter, single-arm study with symptomatic patients undergoing TAVI for treatment of severe aortic valve stenosis using the 18-F Medtronic CoreValve (Medtronic, Minneapolis, Minnesota) prosthesis. In all, 126 patients (mean age 82 years, 42.9% male, mean logistic European System for Cardiac Operative Risk Evaluation score 23.4%) with severe aortic valve stenosis (mean gradient 46.8 mm Hg) underwent the TAVI procedure. Access was transfemoral in all but 2 cases with subclavian access. Retrospective risk stratification classified 54 patients as moderate surgical risk, 51 patients as high-risk operable, and 21 patients as high-risk inoperable. The overall technical success rate was 83.1%. Thirty-day all-cause mortality was 15.2%, without significant differences in the subgroups. At 2 years, all-cause mortality was 38.1%, with a significant difference between the moderate-risk group and the combined high-risk groups (27.8% vs. 45.8%, p = 0.04). This difference was mainly attributable to an increased risk of noncardiac mortality among patients constituting the high-risk groups. Hemodynamic results remained unchanged during follow-up (mean gradient: 8.5 ± 2.5 mm Hg at 30 days and 9.0 ± 3.4 mm Hg at 2 years). Functional class improved in 80% of patients and remained stable over time. There was no incidence of structural valve deterioration. The TAVI procedure provides sustained clinical and hemodynamic benefits for as long as 2 years for patients with symptomatic severe aortic stenosis at increased risk for surgery. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  5. Morphological evaluation of the cerebral blood vessels in the late gestation fetal sheep following hypoxia in utero.

    Science.gov (United States)

    Baburamani, Ana A; Lo, Camden; Castillo-Melendez, Margie; Walker, David W

    2013-01-01

    Hypoxia can significantly contribute to the development of permanent brain injury in the term neonate; however the response of cerebral blood vessels is not well understood. This study aimed to quantitatively measure vascular density and morphology using laminin immunohistochemistry as a marker of blood vessels, and determine the effects of a single, severe bout of hypoxia (umbilical cord occlusion, UCO) late in gestation on the developing cerebrovasculature in fetal sheep. At 124-126 days gestation singleton fetal sheep underwent surgery for implantation of catheters and placement of an inflatable cuff around the umbilical cord. A 10 min UCO or sham UCO (n=5) occurred at 132 days gestation. Fetal brains were collected at 24 h (n=5) or 48 h (n=4) after UCO for vascular density and morphology analysis of laminin immunohistochemistry. 48 h following a single, brief bout of severe hypoxia late in gestation decreased vascular density was seen in the caudate nucleus and no changes in vascular morphology occurred. However closer analysis revealed a significant shift in the frequency of smaller (≤10 μm) to larger (≤100 μm) perimeter blood vessels in periventricular and subcortical white matter. Close examination of the frequency distribution of vascular perimeter highlights that alterations in vascular morphology persist in the near term fetal brain for up to 48 h following a brief (10 min) hypoxia in white but not gray matter. These findings suggest that the near term brain may still be vulnerable to white matter injury following in utero hypoxia. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Use of ESPI in hemodynamics: a means of visualizing vessel blood flow

    Science.gov (United States)

    Tyrer, John R.; Versteeg, Henk K.

    1992-08-01

    The successful development of total hip replacement as an effective surgical technique has been one of the most significant advances in modern orthopaedics. The method has superseded the traditional forms of treatment for hip fractures which involve extensive nailing across the site of the break. However, clinical experience has highlighted failures in both the implant and surrounding bone which have often been attributed to mechanical causes. The problem of optimizing the performance of an implant is very complex and includes a number of interrelated factors: fixation to the bone, strength of the prosthesis itself, wear of articulating surfaces, kinematic requirements, energy absorption, effect of implant position and bone structure in the surrounding area. This paper reports attempts to establish a test facility which can accurately model these parameters and monitor their effects with the intention of providing information for the orthopaedic field. Areas of interest that are intended to be examined include: the effect of bone preservation methods on the bone's strength and weight-bearing characteristics, the effects of medical conditions on bone strength, such as osteoporosis, and the effect of the patient's diet on bone character.

  7. In vitro fabrication of functional three-dimensional tissues with perfusable blood vessels.

    Science.gov (United States)

    Sekine, Hidekazu; Shimizu, Tatsuya; Sakaguchi, Katsuhisa; Dobashi, Izumi; Wada, Masanori; Yamato, Masayuki; Kobayashi, Eiji; Umezu, Mitsuo; Okano, Teruo

    2013-01-01

    In vitro fabrication of functional vascularized three-dimensional tissues has been a long-standing objective in the field of tissue engineering. Here we report a technique to engineer cardiac tissues with perfusable blood vessels in vitro. Using resected tissue with a connectable artery and vein as a vascular bed, we overlay triple-layer cardiac cell sheets produced from coculture with endothelial cells, and support the tissue construct with media perfused in a bioreactor. We show that endothelial cells connect to capillaries in the vascular bed and form tubular lumens, creating in vitro perfusable blood vessels in the cardiac cell sheets. Thicker engineered tissues can be produced in vitro by overlaying additional triple-layer cell sheets. The vascularized cardiac tissues beat and can be transplanted with blood vessel anastomoses. This technique may create new opportunities for in vitro tissue engineering and has potential therapeutic applications.

  8. Three-dimensional display of blood vessels and soft tissues with MR images

    International Nuclear Information System (INIS)

    Shiotani, Y.; Sato, H.; Machida, Y.; Yoshida, T.

    1988-01-01

    The authors developed a three-dimensional display technique for blood vessels related to soft tissues, using MR images generated by the three-dimensional Fourier transform method or multisection method. An application of this study for neurosurgery provided satisfactory results. In this paper they describe this display technique and its clinical practice, including procedures (1) to enhance blood vessels by nonlinear filter capable of detecting three-dimensional line patterns without losing the form of soft tissues, (2) to generate three-dimensional images by the numerical projection, and (3) to present three-dimensional display utilizing the dynamic or binocular parallex (animation display or stereoscopic display). This technique facilitates the recognition of the three-dimensional structure of blood vessels related to soft tissues

  9. Implante transcateter de valva aórtica: resultados atuais do desenvolvimento e implante de um nova prótese brasileira Transcatheter aortic valve implantation: results of the current development and implantation of a new Brazilian prosthesis

    Directory of Open Access Journals (Sweden)

    Diego Felipe Gaia

    2011-09-01

    . Minimally invasive transcatheter aortic valve implantation has emerged as an alternative, with lower morbidity and mortality. The aim of this study was clinical, safety and efficacy assessment. METHODS: Thirty-three high risk patients underwent transcatheter balloon expandable aortic valve implantation. Mean Logistic EuroScore risk was 39.30% and STS score 30.28%. Eight patients presented with dysfunctional bioprosthesis, remaining ones presented calcified aortic stenosis. Procedures were performed in a hybrid OR under fluoroscopic and echocardiography guidance. Using a left minithoracotomy the prosthesis were implanted trough the ventricular apex under rapid ventricular pacing or hemorrhagic shock. Echocardiographic and angiographic controls were performed. RESULTS: Implant was feasible in 30 cases. Three conversions occured. There was only one case of operative death. Median transvalvular aortic gradient reduced from 43.58 mmHg to 10.54 mmHg. Left ventricular function improved in the first 7 postoperative days. Paravalvular aortic regurgitation was mild and present in 30.30%. One case presented major vascular complication and another one permanent pacemaker implant. One major stroke case occurred. Overall 30-day mortality was 18.18%. CONCLUSION: The transapical implantation of catheter mounted bioprosthesis is a safe procedure with acceptable midterm results. Long term follow-up with increased sample power is mandatory in order to access hemodynamic, life quality and survival

  10. Detection of Blood Vessels in Color Fundus Images using a Local Radon Transform

    Directory of Open Access Journals (Sweden)

    Reza Pourreza

    2010-09-01

    Full Text Available Introduction: This paper addresses a method for automatic detection of blood vessels in color fundus images which utilizes two main tools: image partitioning and local Radon transform. Material and Methods: The input images are firstly divided into overlapping windows and then the Radon transform is applied to each. The maximum of the Radon transform in each window corresponds to the probable available sub-vessel. To verify the detected sub-vessel, the maximum is compared with a predefined threshold. The verified sub-vessels are reconstructed using the Radon transform information. All detected and reconstructed sub-vessels are finally combined to make the final vessel tree. Results: The algorithm’s performance was evaluated numerically by applying it to 40 images of DRIVE database, a standard retinal image database. The vessels were extracted manually by two physicians. This database was used to test and compare the available and proposed algorithms for vessel detection in color fundus images. By comparing the output of the algorithm with the manual results, the two parameters TPR and FPR were calculated for each image and the average of TPRs and FPRs were used to plot the ROC curve. Discussion and Conclusion: Comparison of the ROC curve of this algorithm with other algorithms demonstrated the high achieved accuracy. Beside the high accuracy, the Radon transform which is integral-based makes the algorithm robust against noise.

  11. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Shashi, E-mail: shashisharma1984@gmail.com; Katiyar, V.K.; Singh, Uaday

    2015-04-01

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles.

  12. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    International Nuclear Information System (INIS)

    Sharma, Shashi; Katiyar, V.K.; Singh, Uaday

    2015-01-01

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles

  13. Effect of Rolling Massage on the Vortex Flow in Blood Vessels with Lattice Boltzmann Simulation

    Science.gov (United States)

    Yi, Hou Hui

    The rolling massage manipulation is a classic Chinese Medical Massage, which is a nature therapy in eliminating many diseases. Here, the effect of the rolling massage on the cavity flows in blood vessel under the rolling manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the vortex flows are fully disturbed by the rolling massage. The flow behavior depends on the rolling velocity and the rolling depth. Rolling massage has a better effect on the flows in the cavity than that of the flows in a planar blood vessel. The result is helpful to understand the mechanism of the massage and develop the rolling techniques.

  14. An automated blood vessel segmentation algorithm using histogram equalization and automatic threshold selection.

    Science.gov (United States)

    Saleh, Marwan D; Eswaran, C; Mueen, Ahmed

    2011-08-01

    This paper focuses on the detection of retinal blood vessels which play a vital role in reducing the proliferative diabetic retinopathy and for preventing the loss of visual capability. The proposed algorithm which takes advantage of the powerful preprocessing techniques such as the contrast enhancement and thresholding offers an automated segmentation procedure for retinal blood vessels. To evaluate the performance of the new algorithm, experiments are conducted on 40 images collected from DRIVE database. The results show that the proposed algorithm performs better than the other known algorithms in terms of accuracy. Furthermore, the proposed algorithm being simple and easy to implement, is best suited for fast processing applications.

  15. Blood vessel segmentation algorithms - Review of methods, datasets and evaluation metrics.

    Science.gov (United States)

    Moccia, Sara; De Momi, Elena; El Hadji, Sara; Mattos, Leonardo S

    2018-05-01

    Blood vessel segmentation is a topic of high interest in medical image analysis since the analysis of vessels is crucial for diagnosis, treatment planning and execution, and evaluation of clinical outcomes in different fields, including laryngology, neurosurgery and ophthalmology. Automatic or semi-automatic vessel segmentation can support clinicians in performing these tasks. Different medical imaging techniques are currently used in clinical practice and an appropriate choice of the segmentation algorithm is mandatory to deal with the adopted imaging technique characteristics (e.g. resolution, noise and vessel contrast). This paper aims at reviewing the most recent and innovative blood vessel segmentation algorithms. Among the algorithms and approaches considered, we deeply investigated the most novel blood vessel segmentation including machine learning, deformable model, and tracking-based approaches. This paper analyzes more than 100 articles focused on blood vessel segmentation methods. For each analyzed approach, summary tables are presented reporting imaging technique used, anatomical region and performance measures employed. Benefits and disadvantages of each method are highlighted. Despite the constant progress and efforts addressed in the field, several issues still need to be overcome. A relevant limitation consists in the segmentation of pathological vessels. Unfortunately, not consistent research effort has been addressed to this issue yet. Research is needed since some of the main assumptions made for healthy vessels (such as linearity and circular cross-section) do not hold in pathological tissues, which on the other hand require new vessel model formulations. Moreover, image intensity drops, noise and low contrast still represent an important obstacle for the achievement of a high-quality enhancement. This is particularly true for optical imaging, where the image quality is usually lower in terms of noise and contrast with respect to magnetic

  16. Blood Vessel Formation and Bone Regeneration Potential of the Stromal Vascular Fraction Seeded on a Calcium Phosphate Scaffold in the Human Maxillary Sinus Floor Elevation Model

    Directory of Open Access Journals (Sweden)

    Elisabet Farré-Guasch

    2018-01-01

    Full Text Available Bone substitutes are used as alternatives for autologous bone grafts in patients undergoing maxillary sinus floor elevation (MSFE for dental implant placement. However, bone substitutes lack osteoinductive and angiogenic potential. Addition of adipose stem cells (ASCs may stimulate osteogenesis and osteoinduction, as well as angiogenesis. We aimed to evaluate the vascularization in relation to bone formation potential of the ASC-containing stromal vascular fraction (SVF of adipose tissue, seeded on two types of calcium phosphate carriers, within the human MSFE model, in a phase I study. Autologous SVF was obtained from ten patients and seeded on β-tricalcium phosphate (n = 5 or biphasic calcium phosphate carriers (n = 5, and used for MSFE in a one-step surgical procedure. After six months, biopsies were obtained during dental implant placement, and the quantification of the number of blood vessels was performed using histomorphometric analysis and immunohistochemical stainings for blood vessel markers, i.e., CD34 and alpha-smooth muscle actin. Bone percentages seemed to correlate with blood vessel formation and were higher in study versus control biopsies in the cranial area, in particular in β-tricalcium phosphate-treated patients. This study shows the safety, feasibility, and efficiency of the use of ASCs in the human MSFE, and indicates a pro-angiogenic effect of SVF.

  17. Use of a cross-mounting buccal index to help transfer the spatial relationships of an interim prosthesis to the definitive implant-supported prosthesis.

    Science.gov (United States)

    Chaimattayompol, N; Stanescu, J; Steinberg, J; Vergo, T J

    2001-05-01

    This article describes a new method for the fabrication of an index for definitive implant abutment selection, framework design, and fabrication. After the interim removable restoration is esthetically and functionally accepted by the patient and dentist, it can be used as a surgical guide during implant placement as well as a guide for abutment selection, framework design, and fabrication. The concepts used in the fabrication of the cross-mounting buccal index include having a reference point, maintaining the vertical dimension of occlusion, and supplying the ability for cross mounting. This procedure allows the clinician to use a duplicate of the interim restoration to select the abutments and fabricate the framework without a new denture setup. It also accelerates both patient chairtime and laboratory time, and it enhances the prosthodontic outcome.

  18. A comparative evaluation of linear dimensional accuracy of the dies obtained using three conceptually different die systems in the fabrication of implant prosthesis: An in vitro study

    Directory of Open Access Journals (Sweden)

    Manawar Ahmad

    2014-01-01

    Purpose: The purpose of the study was to evaluate the linear dimensional accuracy between the implant master die and three conceptually different die systems such as Pindex system, Accu-trac precision die system, and Conventional brass dowel pin system. Materials and Methods: Thirty impressions of implant master die were made with polyether impression material. Ten experimental implant casts were fabricated for each of the three different die systems tested: Accu-trac precision die tray system, Pindex system, and conventional brass dowel pin system. The solid experimental casts were sectioned and then removed from the die system 30 times. Linear distances between all six possible distances were measured from one centre of the transfer coping to the other, using a co-ordinate measuring machine in millimeters up to accuracy of 0.5 microns. Data were tabulated and statistically analyzed by Binomial non parametric test using SPSS version 15. Results: Significant differences were found for distance A-B (P = 0.002, A-C ( P = 0.002, A-D (P value = 0.002, and B-D ( P = 0.021 in Conventional Dowel pin system however for Accu-trac precision die tray system, it was significant only for distance A-D (P = 0.002 but for Pindex system it was non-significant for all the distances measured. Conclusion: Within the limitations of this study, use of Pindex system is recommended when sectioned dies are needed for a multi implant retained prosthesis.

  19. Transcatheter aortic valve-in-valve implantation of a CoreValve in a JenaValve prosthesis: a case report.

    Science.gov (United States)

    Lotfi, Shahram; Becker, Michael; Moza, Ajay; Autschbach, Rüdiger; Marx, Nikolaus; Schröder, Jörg

    2017-09-10

    Transcatheter aortic valve implantation has become an accepted treatment modality for inoperable or high-risk surgical patients with symptomatic severe aortic stenosis. We report the case of a 70-year-old white man who was treated for severe symptomatic aortic regurgitation using transcatheter aortic valve implantation from the apical approach. Because of recurrent cardiac decompensation 4 weeks after implantation he underwent the implantation of a left ventricular assist device system. A year later echocardiography showed a severe transvalvular central insufficiency. Our heart team decided to choose a valve-in-valve approach while reducing the flow rate of left ventricular assist device to minimum and pacing with a frequency of 140 beats/minute. There was an excellent result and our patient is doing well with no relevant insufficiency of the aortic valve at 12-month follow-up. This is the first report about a successful treatment of a stenotic JenaValve using a CoreValve Evolut R; the use of a CoreValve Evolut R prosthesis may be an optimal option for valve-in-valve procedures.

  20. Compressed sensing based simultaneous black- and gray-blood carotid vessel wall MR imaging.

    Science.gov (United States)

    Li, Bo; Li, Hao; Kong, Hanjing; Dong, Li; Zhang, Jue; Fang, Jing

    2017-05-01

    In this study, we sought to demonstrate the blood suppression performance, image quality and morphological measurements for compressed sensing (CS) based simultaneous 3D black- and gray-blood imaging sequence (CS-siBLAG) in carotid vessel wall MR imaging. Seven healthy volunteers and five patients were recruited. Healthy subjects underwent five CS-siBLAG scans with 1, 2, 3, 4 and 5-fold accelerations. Signal-to-tissue ratio (STR) and contrast-to-tissue ratio (CTR) were computed as the measures of flowing signal suppression performance and the image quality for black-blood imaging of the technique. Vessel lumen area (LA) and wall area (WA) were compared between fully sampled acquisition and each accelerated acquisition. Patients underwent three CS-siBLAG scans with 1, 3 and 5-fold accelerations as well as a 3D time of flight (3D TOF) scan. Two radiologists reviewed the under-sampled black- and gray-blood image quality. STR and CTR values obtained with 2 to 5-fold accelerations were not significantly different from those with full acquisition. LA and WA measured at 2×, 3×, 4× and 5× were all highly correlated to the corresponding values at 1×. For patients imaging, two radiologists both found that the dual-contrast images at 3× acceleration exhibited comparable image quality to that of the fully sampled acquisition, and that the images at 5× exhibited slightly blurred vessel wall and outer vessel wall boundaries. By combining the CS under-sampling pattern and reconstruction, pseudo-centric phase encoding order and dual blood contrast sequences, this technique provides spatially registered black- and gray-blood images and excellent visualization for vessel wall imaging and gray-blood imaging in a short scan time. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Contact-inhibited chemotaxis in de novo and sprouting blood-vessel growth.

    Directory of Open Access Journals (Sweden)

    Roeland M H Merks

    2008-09-01

    Full Text Available Blood vessels form either when dispersed endothelial cells (the cells lining the inner walls of fully formed blood vessels organize into a vessel network (vasculogenesis, or by sprouting or splitting of existing blood vessels (angiogenesis. Although they are closely related biologically, no current model explains both phenomena with a single biophysical mechanism. Most computational models describe sprouting at the level of the blood vessel, ignoring how cell behavior drives branch splitting during sprouting. We present a cell-based, Glazier-Graner-Hogeweg model (also called Cellular Potts Model simulation of the initial patterning before the vascular cords form lumens, based on plausible behaviors of endothelial cells. The endothelial cells secrete a chemoattractant, which attracts other endothelial cells. As in the classic Keller-Segel model, chemotaxis by itself causes cells to aggregate into isolated clusters. However, including experimentally observed VE-cadherin-mediated contact inhibition of chemotaxis in the simulation causes randomly distributed cells to organize into networks and cell aggregates to sprout, reproducing aspects of both de novo and sprouting blood-vessel growth. We discuss two branching instabilities responsible for our results. Cells at the surfaces of cell clusters attempting to migrate to the centers of the clusters produce a buckling instability. In a model variant that eliminates the surface-normal force, a dissipative mechanism drives sprouting, with the secreted chemical acting both as a chemoattractant and as an inhibitor of pseudopod extension. Both mechanisms would also apply if force transmission through the extracellular matrix rather than chemical signaling mediated cell-cell interactions. The branching instabilities responsible for our results, which result from contact inhibition of chemotaxis, are both generic developmental mechanisms and interesting examples of unusual patterning instabilities.

  2. Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

    Directory of Open Access Journals (Sweden)

    Barleon Bernhard

    2010-07-01

    Full Text Available Abstract Background Postnatal endothelial progenitor cells (EPCs have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. Results In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of de novo vasculogenesis for blood and lymph vessels. Mouse lung microvascular endothelial cells (MLMVECs were isolated by selection of CD31+ cells. Whereas the majority of the CD31+ cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony. These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined in vitro and in vivo spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels. Conclusion The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.

  3. Resonance frequency of microbubbles in small blood vessels: a numerical study

    International Nuclear Information System (INIS)

    Sassaroli, E; Hynynen, K

    2005-01-01

    Microbubbles are currently used as ultrasound contrast agents. Their potential therapeutic applications are also under investigation. This work is designed to provide some insight into the mechanisms of energy absorption and deposition by a preformed gas bubble in the microvasculature to optimize its efficacy. In the linear regime, the most favourable condition for the transfer of energy from an ultrasonic field to a gas bubble occurs when the centre frequency of the ultrasonic field equals the resonance frequency of the bubble. The resonance frequency of gas microbubbles has been investigated up to now mainly in unbounded liquids; however when bubbles are confined in small regions, their resonance frequency is strongly affected by the surrounding boundaries. A parametric study on how the resonance frequency of microbubbles in blood vessels is affected by the bubble radius, vessel radius and the bubble position in the vessel is presented. The resonance frequency decreases below its free value with decreasing vessel radius for vessels smaller than 200-300 μm depending on the bubble size. This model suggests the possibility of using ultrasound in a range of frequencies that are, in general, lower than the ones used now for therapeutic and diagnostic applications of ultrasound (a few MHz). When microbubbles oscillate at their resonance frequency they absorb and therefore emit more energy. This energy may allow specific blood vessels to be targeted for both diagnostic and therapeutic applications of ultrasound

  4. 21 CFR 872.3960 - Mandibular condyle prosthesis.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3960 Mandibular condyle prosthesis. (a) Identification. A mandibular condyle prosthesis is a device that is intended to be implanted in the human jaw to... requirement for premarket approval for any mandibular condyle prosthesis intended to be implanted in the human...

  5. Wave reflection and transmission in multiply stented blood vessels

    Science.gov (United States)

    Papathanasiou, T. K.; Movchan, A. B.; Bigoni, D.

    2017-06-01

    Closed circulatory systems display an exquisite balance between vascular elasticity and viscous fluid effects, to induce pulse-smoothing and avoid resonance during the cardiac cycle. Stents in the arterial tree alter this balance through stiffening and because a periodic structure is introduced, capable of interacting with the fluid in a complex way. While the former feature has been investigated, the latter received no attention so far. But periodic structures are the building blocks of metamaterials, known for their `non-natural' behaviour. Thus, the investigation of a stent's periodic microstructure dynamical interactions is crucial to assess possible pathological responses. A one-dimensional fluid-structure interaction model, simple enough to allow an analytical solution for situations of interest involving one or two interacting stents, is introduced. It is determined: (i) whether or not frequency bands exist in which reflected blood pulses are highly increased and (ii) if these bands are close to the characteristic frequencies of arteries and finally, (iii) if the internal structure of the stent can sensibly affect arterial blood dynamics. It is shown that, while the periodic structure of an isolated stent can induce anomalous reflection only in pathological conditions, the presence of two interacting stents is more critical, and high reflection can occur at frequencies not far from the physiological values.

  6. Mathematical Modeling of Bingham Plastic Model of Blood Flow Through Stenotic Vessel

    OpenAIRE

    S.R. Verma

    2014-01-01

    The aim of the present paper is to study the axially symmetric, laminar, steady, one-dimensional flow of blood through narrow stenotic vessel. Blood is considered as Bingham plastic fluid. The analytical results such as pressure drop, resistance to flow and wall shear stress have been obtained. Effect of yield stress and shape of stenosis on resistance to flow and wall shear stress have been discussed through tables and graphically. It has been shown that resistance to flow and th...

  7. Failure to show decrease in small pulmonary blood vessels in rats with experimental pulmonary hypertension.

    OpenAIRE

    Kay, J M; Suyama, K L; Keane, P M

    1982-01-01

    We induced chronic pulmonary hypertension in one group of rats by exposing them to chronic hypobaric hypoxia (380 mm Hg for three weeks) and in another group by administering a single subcutaneous dose of monocrotaline (60 mg/kg body weight). Both groups of rats showed increase of the right ventricular mean systolic blood pressure and right ventricular hypertrophy. We measured the surface area of histological sections of the left or right lungs and counted all small blood vessels with an exte...

  8. Blood vessel extraction and optic disc removal using curvelet transform and kernel fuzzy c-means.

    Science.gov (United States)

    Kar, Sudeshna Sil; Maity, Santi P

    2016-03-01

    This paper proposes an automatic blood vessel extraction method on retinal images using matched filtering in an integrated system design platform that involves curvelet transform and kernel based fuzzy c-means. Since curvelet transform represents the lines, the edges and the curvatures very well and in compact form (by less number of coefficients) compared to other multi-resolution techniques, this paper uses curvelet transform for enhancement of the retinal vasculature. Matched filtering is then used to intensify the blood vessels' response which is further employed by kernel based fuzzy c-means algorithm that extracts the vessel silhouette from the background through non-linear mapping. For pathological images, in addition to matched filtering, Laplacian of Gaussian filter is also employed to distinguish the step and the ramp like signal from that of vessel structure. To test the efficacy of the proposed method, the algorithm has also been applied to images in presence of additive white Gaussian noise where the curvelet transform has been used for image denoising. Performance is evaluated on publicly available DRIVE, STARE and DIARETDB1 databases and is compared with the large number of existing blood vessel extraction methodologies. Simulation results demonstrate that the proposed method is very much efficient in detecting the long and the thick as well as the short and the thin vessels with an average accuracy of 96.16% for the DRIVE and 97.35% for the STARE database wherein the existing methods fail to extract the tiny and the thin vessels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. The Fine Structure of Some Blood Vessels of the Earthworm, Eisenia foetida

    Science.gov (United States)

    Hama, Kiyoshi

    1960-01-01

    The fine structure of the main dorsal and ventral circulatory trunks and of the subneural vessels and capillaries of the ventral nerve cord of the earthworm, Eisenia foetida, has been studied with the electron microscope. All of these vessels are lined internally by a continuous extracellular basement membrane varying in thickness (0.03 to 1 µ) with the vessel involved. The dorsal, ventral, and subneural vessels display inside this membrane scattered flattened macrophagic or leucocytic cells called amebocytes. These lie against the inner lining of the basement membrane, covering only a small fraction of its surface. They have long, attenuated branching cell processes. All of these vessels are lined with a continuous layer of unfenestrated endothelial cells displaying myofilaments and hence qualifying for the designation of "myoendothelial cells." The degree of muscular specialization varies over a spectrum, however, ranging from a delicate endowment of thin myofilaments in the capillary myoendothelial cells to highly specialized myoendothelial cells in the main pulsating dorsal blood trunk, which serves as the worm's "heart" or propulsive "aorta." The myoendothelial cells most specialized for contraction display well organized sarcoplasmic reticulum and myofibrils with thick and thin myofilaments resembling those of the earthworm body wall musculature. In the ventral circulatory trunk, circular and longitudinal myofilaments are found in each myoendothelial cell. In the dorsal trunk, the lining myoendothelial cells contain longitudinal myofilaments. Outside these cells are circular muscle cells. The lateral parts of the dorsal vessels have an additional outer longitudinal muscle layer. The blood plasma inside all of the vessels shows scattered particles representing the circulating earthworm blood pigment, erythrocruorin. PMID:14399190

  10. Cerebral blood flow in small vessel disease : A systematic review and meta-analysis

    NARCIS (Netherlands)

    Shi, Yulu; Thrippleton, Michael J; Makin, Stephen D; Marshall, Ian; Geerlings, Mirjam I; de Craen, Anton Jm; van Buchem, Mark A; Wardlaw, Joanna M

    2016-01-01

    White matter hyperintensities are frequent on neuroimaging of older people and are a key feature of cerebral small vessel disease. They are commonly attributed to chronic hypoperfusion, although whether low cerebral blood flow is cause or effect is unclear. We systematically reviewed studies that

  11. Photoacoustic imaging of blood vessels with a double-ring sensor featuring a narrow angular aperture

    NARCIS (Netherlands)

    Kolkman, R.G.M.; Hondebrink, Erwin; Steenbergen, Wiendelt; van Leeuwen, Ton; de Mul, F.F.M.

    2004-01-01

    A photoacoustic double-ring sensor, featuring a narrow angular aperture, is developed for laser-induced photoacoustic imaging of blood vessels. An integrated optical fiber enables reflection-mode detection of ultrasonic waves. By using the cross-correlation between the signals detected by the two

  12. Mass Spectrometry and Antibody-Based Characterization of Blood Vessels from Brachylophosaurus canadensis.

    Science.gov (United States)

    Cleland, Timothy P; Schroeter, Elena R; Zamdborg, Leonid; Zheng, Wenxia; Lee, Ji Eun; Tran, John C; Bern, Marshall; Duncan, Michael B; Lebleu, Valerie S; Ahlf, Dorothy R; Thomas, Paul M; Kalluri, Raghu; Kelleher, Neil L; Schweitzer, Mary H

    2015-12-04

    Structures similar to blood vessels in location, morphology, flexibility, and transparency have been recovered after demineralization of multiple dinosaur cortical bone fragments from multiple specimens, some of which are as old as 80 Ma. These structures were hypothesized to be either endogenous to the bone (i.e., of vascular origin) or the result of biofilm colonizing the empty osteonal network after degradation of original organic components. Here, we test the hypothesis that these structures are endogenous and thus retain proteins in common with extant archosaur blood vessels that can be detected with high-resolution mass spectrometry and confirmed by immunofluorescence. Two lines of evidence support this hypothesis. First, peptide sequencing of Brachylophosaurus canadensis blood vessel extracts is consistent with peptides comprising extant archosaurian blood vessels and is not consistent with a bacterial, cellular slime mold, or fungal origin. Second, proteins identified by mass spectrometry can be localized to the tissues using antibodies specific to these proteins, validating their identity. Data are available via ProteomeXchange with identifier PXD001738.

  13. Total Artificial Heart Implantation Blood Pressure Management as Resolving Treatment for Massive Hemolysis following Total Artificial Heart Implantation.

    Science.gov (United States)

    Ghodsizad, Ali; Koerner, Michael M; El-Banayosy, A; Zeriouh, Mohamed; Ruhparwar, Arjang; Loebe, Matthias

    2016-10-21

    The SynCardia Total Artificial Heart (TAH) has been used for patients with biventricular failure, who cannot be managed with implantation of a left ventricular (LV) assist device. Following TAH implantation, our patient developed severe hemolysis, which could only be managed successfully by aggressive blood pressure control [Ohashi 2003; Nakata 1998].

  14. New 3D technologies applied to assess the long-term clinical effects of misfit of the full jaw fixed prosthesis on dental implants.

    Science.gov (United States)

    Jokstad, Asbjørn; Shokati, Babak

    2015-10-01

    To assess implant:suprastructure misfit in patients with an edentulous jaw restored by an implant-retained fixed dental prosthesis (FDP) and its association with biologic and mechanical adverse events over an extensive period. Thirty patients with an edentulous mandible treated with implant-supported prosthetics before 2000 were examined clinically in 2012. Each patient had received 4 to 6 implants to retain a FDP made from acrylic and three different metal alloys, that is, Ag-Pd, Pd-Ag, and Au type IV. The implant intra-oral locations were recorded digitally by use of an intra-oral scanner, and the intaglio surface of the detached FDP was recorded using a desktop scanner. The fit was estimated by digital matching of the STL files using industrial metrological software. The average misfit was correlated with the average marginal bone loss and the prevalence of screw loosening or fractures, using the patient as the statistical unit. Over an average of 19 years (range 12 to 32), 5 implants had been lost in 4 participants (96.7% implant survival) and 8 eight prostheses (26.7%) had been remade. Anaverage misfit was 150 μm (SD 35, range 95-232, CI 138-163). An average marginal bone loss of 2.2 mm (SD = 0.7) had occurred (range 0.6 to 5.8 mm) for individual implants. The correlation between framework misfit and marginal bone loss was weak (R² = 0.04) (P = 0.29). The prostheses with a history of screw-related adverse events showed average misfit of 169 μm (SD = 32) vs. those with no history of screw-related adverse events, that is, 134 μm (SD = 30) (P = 0.005, Student's t-test). Fourteen of the 30 participants had experienced at least one incidence of screw loosening or fracture of prosthetic or abutment screw(s) over the period of follow-up. The occurrence among the frameworks fabricated with different metal alloys did not differ (P > 0.05, Fisher's exact test). Combining STL files with best-fit algorithms to appraise misfit is feasible using

  15. Hybrid PIV-PTV technique for measuring blood flow in rat mesenteric vessels.

    Science.gov (United States)

    Ha, Hojin; Nam, Kweon-Ho; Lee, Sang Joon

    2012-11-01

    The micro-particle tracking velocimetry (μ-PTV) technique is used to obtain the velocity fields of blood flow in the microvasculature under in vivo conditions because it can provide the blood velocity distribution in microvessels with high spatial resolution. The in vivo μ-PTV technique usually requires a few to tens of seconds to obtain a whole velocity profile across the vessel diameter because of the limited number density of tracer particles under in vivo conditions. Thus, the μ-PTV technique alone is limited in measuring unsteady blood flows that fluctuate irregularly due to the heart beating and muscle movement in surrounding tissues. In this study, a new hybrid PIV-PTV technique was established by combining PTV and particle image velocimetry (PIV) techniques to resolve the drawbacks of the μ-PTV method in measuring blood flow in microvessels under in vivo conditions. Images of red blood cells (RBCs) and fluorescent particles in rat mesenteric vessels were obtained simultaneously. Temporal variations of the centerline blood velocity were monitored using a fast Fourier transform-based cross-correlation PIV method. The fluorescence particle images were analyzed using the μ-PTV technique to extract the spatial distribution of the velocity vectors. Data from the μ-PTV and PIV methods were combined to obtain a better estimate of the velocity profile in actual blood flow. This technique will be useful in investigating hemodynamics in microcirculation by measuring unsteady irregular blood flows more accurately. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. 21 CFR 872.3950 - Glenoid fossa prosthesis.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3950 Glenoid fossa prosthesis. (a) Identification. A glenoid fossa prosthesis is a device that is intended to be implanted in the temporomandibular...

  17. Optics based signal processing methods for intraoperative blood vessel detection and quantification in real time (Conference Presentation)

    Science.gov (United States)

    Chaturvedi, Amal; Shukair, Shetha A.; Le Rolland, Paul; Vijayvergia, Mayank; Subramanian, Hariharan; Gunn, Jonathan W.

    2016-03-01

    Minimally invasive operations require surgeons to make difficult cuts to blood vessels and other tissues with impaired tactile and visual feedback. This leads to inadvertent cuts to blood vessels hidden beneath tissue, causing serious health risks to patients and a non-reimbursable financial burden to hospitals. Intraoperative imaging technologies have been developed, but these expensive systems can be cumbersome and provide only a high-level view of blood vessel networks. In this research, we propose a lean reflectance-based system, comprised of a dual wavelength LED, photodiode, and novel signal processing algorithms for rapid vessel characterization. Since this system takes advantage of the inherent pulsatile light absorption characteristics of blood vessels, no contrast agent is required for its ability to detect the presence of a blood vessel buried deep inside any tissue type (up to a cm) in real time. Once a vessel is detected, the system is able to estimate the distance of the vessel from the probe and the diameter size of the vessel (with a resolution of ~2mm), as well as delineate the type of tissue surrounding the vessel. The system is low-cost, functions in real-time, and could be mounted on already existing surgical tools, such as Kittner dissectors or laparoscopic suction irrigation cannulae. Having been successfully validated ex vivo, this technology will next be tested in a live porcine study and eventually in clinical trials.

  18. Establishing the maxillary occlusal plane as a requisite for placement of an immediate implant-supported fixed prosthesis in the mandible: a case report

    Directory of Open Access Journals (Sweden)

    Milton Edson Miranda

    Full Text Available INTRODUCTION: In patients with Bruxism, the attrition can result in excessive occlusal wear that exceeds the compensatory mechanism and loss of occlusion vertical dimension occurs. OBJECTIVE: The purpose of this article is to show the importance of re-establishing an adequate occlusal plane for the non treated arch by means of a fixed acrylic overlay, compatible with the prosthetic treatment of the arch to be rehabilitated. An upper maxillary fixed acrylic overlay restored the patient’s occlusal plane in an appropriate vertical dimension of occlusion together with a fixed prosthesis in the mandible, supported by five dental implants. CONCLUSION: When there is severe wear due to dental attrition in one of the arches, it is important to re-establish the occlusal plane and compensation curves in conjunction with the prosthetic treatment of the arch to be rehabilitated.

  19. Skeletonization algorithm-based blood vessel quantification using in vivo 3D photoacoustic imaging

    Science.gov (United States)

    Meiburger, K. M.; Nam, S. Y.; Chung, E.; Suggs, L. J.; Emelianov, S. Y.; Molinari, F.

    2016-11-01

    Blood vessels are the only system to provide nutrients and oxygen to every part of the body. Many diseases can have significant effects on blood vessel formation, so that the vascular network can be a cue to assess malicious tumor and ischemic tissues. Various imaging techniques can visualize blood vessel structure, but their applications are often constrained by either expensive costs, contrast agents, ionizing radiations, or a combination of the above. Photoacoustic imaging combines the high-contrast and spectroscopic-based specificity of optical imaging with the high spatial resolution of ultrasound imaging, and image contrast depends on optical absorption. This enables the detection of light absorbing chromophores such as hemoglobin with a greater penetration depth compared to purely optical techniques. We present here a skeletonization algorithm for vessel architectural analysis using non-invasive photoacoustic 3D images acquired without the administration of any exogenous contrast agents. 3D photoacoustic images were acquired on rats (n  =  4) in two different time points: before and after a burn surgery. A skeletonization technique based on the application of a vesselness filter and medial axis extraction is proposed to extract the vessel structure from the image data and six vascular parameters (number of vascular trees (NT), vascular density (VD), number of branches (NB), 2D distance metric (DM), inflection count metric (ICM), and sum of angles metric (SOAM)) were calculated from the skeleton. The parameters were compared (1) in locations with and without the burn wound on the same day and (2) in the same anatomic location before (control) and after the burn surgery. Four out of the six descriptors were statistically different (VD, NB, DM, ICM, p  burn surgery). The study demonstrates an approach to obtain quantitative characterization of the vascular network from 3D photoacoustic images without any exogenous contrast agent which can assess

  20. A thresholding based technique to extract retinal blood vessels from fundus images

    Directory of Open Access Journals (Sweden)

    Jyotiprava Dash

    2017-12-01

    Full Text Available Retinal imaging has become the significant tool among all the medical imaging technology, due to its capability to extract many data which is linked to various eye diseases. So, the accurate extraction of blood vessel is necessary that helps the eye care specialists and ophthalmologist to identify the diseases at the early stages. In this paper, we have proposed a computerized technique for extraction of blood vessels from fundus images. The process is conducted in three phases: (i pre-processing where the image is enhanced using contrast limited adaptive histogram equalization and median filter, (ii segmentation using mean-C thresholding to extract retinal blood vessels, (iii post-processing where morphological cleaning operation is used to remove isolated pixels. The performance of the proposed method is tested on and experimental results show that our method achieve an accuracies of 0.955 and 0.954 on Digital retinal images for vessel extraction (DRIVE and Child heart and health study in England (CHASE_DB1 databases respectively.

  1. Vascular patterns in the heads of crocodilians: blood vessels and sites of thermal exchange.

    Science.gov (United States)

    Porter, William Ruger; Sedlmayr, Jayc C; Witmer, Lawrence M

    2016-12-01

    Extant crocodilians are a highly apomorphic archosaur clade that is ectothermic, yet often achieve large body sizes that can be subject to higher heat loads. Therefore, the anatomical and physiological roles that blood vessels play in crocodilian thermoregulation need further investigation to better understand how crocodilians establish and maintain cephalic temperatures and regulate neurosensory tissue temperatures during basking and normal activities. The cephalic vascular anatomy of extant crocodilians, particularly American alligator (Alligator mississippiensis) was investigated using a differential-contrast, dual-vascular injection technique and high resolution X-ray micro-computed tomography (μCT). Blood vessels were digitally isolated to create representations of vascular pathways. The specimens were then dissected to confirm CT results. Sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in evaporative cooling and cephalic thermoregulation in other diapsids. Blood vessels to and from sites of thermal exchange were studied to detect conserved vascular patterns and to assess their ability to deliver cooled blood to neurosensory tissues. Within the orbital region, both the arteries and veins demonstrated consistent branching patterns, with the supraorbital, infraorbital, and ophthalmotemporal vessels supplying and draining the orbit. The venous drainage of the orbital region showed connections to the dural sinuses via the orbital veins and cavernous sinus. The palatal region demonstrated a vast plexus that comprised both arteries and veins. The most direct route of venous drainage of the palatal plexus was through the palatomaxillary veins, essentially bypassing neurosensory tissues. Anastomotic connections with the nasal region, however, may provide an alternative route for palatal venous blood to reach neurosensory tissues. The nasal region in crocodilians is probably the most

  2. Study for a portable IR sensor to detect the blood temperature during coronary bypass implantation

    Science.gov (United States)

    Giovannetti, Giulio; Hartwig, Valentina; Francesconi, Raffaello; Landini, Luigi; Benassi, Antonio

    2005-08-01

    The objective of this research was to investigate the possibility of using an infrared prototype device for the detection of the blood temperature during a surgical operation for coronary bypass implantation. The correlation between the fluid temperature time behavior and the fluid flow rate was demonstrated. Each blood vessel acts like a thermal wave emitter, so the amount of heat is proportional to the blood flow detected by the IR sensor. The idea was to design a low cost portable device with the advantage that it can be placed near the region of interest. We chose a pyroelectric sensor for its high-quality cost ratio. Because this kind of sensor detects only a variable infrared source, we used an electromechanical chopper for modulating the radiation. It consists of an electronic shutter whose opening speed is controlled by an astable multivibrator. The output signal was analyzed using a dedicated electronic circuit including a bandpass filter and an amplifier; then an acquisition board was employed for capturing and displaying the signal using a PC. Prototype assessment was made with laboratory equipment and in vivo measurements were made during surgical operation on a small pig.

  3. Towards cavitation-enhanced permeability in blood vessel on a chip

    Science.gov (United States)

    De Luca, R.; Silvani, G.; Scognamiglio, C.; Sinibaldi, G.; Peruzzi, G.; Chinappi, M.; Kiani, M. F.; Casciola, C. M.

    2017-08-01

    The development of targeted delivery systems releasing pharmaceutical agents directly at the desired site of action may improve their therapeutic efficiency while minimizing damage to healthy tissues, toxicity to the patient and drug waste. In this context, we have developed a bio-inspired microdevice mimicking the tumour microvasculature which represents a valuable tool for assessing the enhancement of blood vessel permeability due to cavitation. This novel system allows us to investigate the effects of ultrasound-driven microbubbles that temporarily open the endothelial intercellular junctions allowing drug to extravasate blood vessels into tumour tissues. The blood vessel on a chip consists of a tissue chamber and two independent vascular channels (width 200 µm, height 100 µm, length 2762 µm) cultured with endothelial cells placed side-by-side and separated by a series of 3 µm pores. Its geometry and dimensions mimic the three-dimensional morphology, size and flow characteristics of microvessels in vivo. The early stage of this project had a twofold objective: 1. To define the protocol for culturing of Human Umbilical Vein Endothelial Cells (HUVECs) within the vascular channel; 2. To develop a fluorescence based microscopy technique for measuring permeability. We have developed a reliable and reproducible protocol to culture endothelial cells within the artificial vessels in a realistic manner: HUVECs show the typical elongated shape in the direction of flow, exhibit tight junction formation and form a continuous layer with a central lumen that completely covers the channels wall. As expected, the permeability of cell-free device is higher than the one cultured with HUVECs in the vascular channels. The proposed blood vessel on a chip and the permeability measurement protocol have a significant potential to allow for the study of cavitation-enhanced permeability of the endothelium and improve efficiency in screening drug delivery systems.

  4. An implantable centrifugal blood pump for long term circulatory support.

    Science.gov (United States)

    Yamazaki, K; Litwak, P; Kormos, R L; Mori, T; Tagusari, O; Antaki, J F; Kameneva, M; Watach, M; Gordon, L; Umezu, M; Tomioka, J; Koyanagi, H; Griffith, B P

    1997-01-01

    A compact centrifugal blood pump was developed as an implantable left ventricular assist system. The impeller diameter is 40 mm and the pump dimensions are 55 x 64 mm. This first prototype was fabricated from titanium alloy, resulting in a pump weight of 400 g including a brushless DC motor. Weight of the second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon to improve blood compatibility. Flow rates of over 7 L/min against 100 mmHg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system ("Cool-Seal") is used as a shaft seal. In this seal system, seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. The purge fluid is continuously purified and sterilized by an ultrafiltration filter incorporated into the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular apex-descending aorta bypass was performed utilizing a PTFE (Polytetrafluoroethylene) vascular graft, with the pump placed in the left thoracic cavity. In two in vivo experiments, pump flow rate was maintained at 5-8 L/min, and pump power consumption remained stable at 9-10 W. All plasma free hemoglobin levels were measured at < 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (< 0.5 ml/ day). Both animals remain under observation after 162 and 91 days of continuous pump function.

  5. Numerical analysis of an osseointegrated prosthesis fixation with reduced bone failure risk and periprosthetic bone loss

    NARCIS (Netherlands)

    Tomaszewski, P. M.; van Diest, M.; Bulstra, S. K.; Verdonschot, N.; Verkerke, G. J.

    2012-01-01

    Currently available implants for direct attachment of prosthesis to the skeletal system after transfemoral amputation (OPRA system. Integrum AB, Sweden and ISP Endo/Exo prosthesis, ESKA Implants AG, Germany) show many advantages over the conventional socket fixation. However, restraining

  6. In vivo measurement of hemodynamic information in stenosed rat blood vessels using X-ray PIV.

    Science.gov (United States)

    Park, Hanwook; Park, Jun Hong; Lee, Sang Joon

    2016-11-28

    Measurements of the hemodynamic information of blood flows, especially wall shear stress (WSS), in animal models with circulatory vascular diseases (CVDs) are important to understand the pathological mechanism of CVDs. In this study, X-ray particle image velocimetry (PIV) with high spatial resolution was applied to obtain velocity field information in stenosed blood vessels with high WSS. 3D clips fabricated with a 3D printer were applied to the abdominal aorta of a rat cadaver to induce artificial stenosis in the real blood vessel of an animal model. The velocity and WSS information of blood flows in the stenosed vessel were obtained and compared at various stenosis severities. In vivo measurement was also conducted by fastening a stenotic clip on a live rat model through surgical intervention to reduce the flow rate to match the limited temporal resolution of the present X-ray PIV system. Further improvement of the temporal resolution of the system might be able to provide in vivo measurements of hemodynamic information from animal disease models under physiological conditions. The present results would be helpful for understanding the relation between hemodynamic characteristics and the pathological mechanism in animal CVD models.

  7. [Topography of the blood vessels in the hilum of the kidney of Myrmecophaga tridactyla].

    Science.gov (United States)

    Souza, W M; Miglino, M A; Arantes, I G; Nascimento, A A

    1991-01-01

    The study was undertaken in 10 formol-imbibed kidneys of great anteater (Myrmecophaga tridactyla). After the dissection the following characteristics were showed: kidney blood vessels are distributed in 2 different sites, namely hilar and extrahilar, amounting 3 to 6 in the right side 3 to 7 in the left side. Arterial branches in extrahilar region range from 1 to 2 in both sides and in hilar region they present from 1 to 4 in the right and 1 to 2 in the left. Venous roots occur in 1 to 2 vessels in the right and 1 to 3 vessels in the left, occupying only the hilar region, except one case where it was present in the right side.

  8. Non-Newtonian Mathematical Model and Numerical Simulations for the Blood Flow in Capillary Vessels

    Directory of Open Access Journals (Sweden)

    Balazs ALBERT

    2016-03-01

    Full Text Available In this paper, taking into consideration the rheological Cross type non-Newtonian model, we elaborate an axial-symmetric mathematical model for the blood flow in capillary vessel with adequate numeric algorithms. We take into account the elastic and porous behavior of the vessel wall which leads to a more realistic approach of the problem. We also accept that the change of substances through these vessels complies with the Starling hypothesis. This hypothesis states that the mass debit through the capillary wall is proportional to the pressure difference between outside and inside the capillaries. The existence of a slip condition along the permeable surface is also accepted using the results of Beavers and Joseph. The numerical experiments are made using COMSOL Multiphysics 3.3. Some numerical results with respect to the velocity field, pressure variation and the wall shear stress are presented.

  9. [Imaging Blood Flow and Pulsation of Retinal Vessels with Full-Field Swept-Source OCT].

    Science.gov (United States)

    Spahr, H; Hillmann, D; Hain, C; Pfäffle, C; Sudkamp, H; Franke, G; Koch, P; Hüttmann, G

    2016-12-01

    Optical coherence tomography (OCT) uses interference to image the retina with high axial resolution. In the last 25 years, new technologies have permitted a steady increase in imaging speed, which made it possible to enlarge the imaged field and to avoid motion artefacts. The speed and precision of retinal imaging is now limited by photodamage of the retina caused by the focused OCT beam and by the speed of the scanning mechanics. Full-field swept-source (FF-SS)-OCT decreases irradiance on the retina and dispenses moving parts by using a camera to acquire the full volume of the retina in parallel. Here we show that FF-SS-OCT is rapid and precise enough to image pulsation in the retina induced by the heart beat. Series of OCT volumes 1.8 × 0.7 mm wide and 1.8 mm deep were recorded in young volunteers over a few cycles of the heart beat. Morphology of the retinal vessels, blood flow and tissue motion as caused by vessel pulsation were calculated from the OCT data. FF-SS-OCT was able to visualise the main structures of the neuronal retina, including vessels and small capillaries and without any motion artefacts. Information on three different dynamic processes was obtained from only one recorded series of OCT volumes: pulsation of blood flow and blood pressure in retinal vessels as well as pulsation of the choroid. Delays between arterial and venous pulse and delay between pulsation in retinal and choroidal vessels were calculated. With a time resolution of 0.5 ms, FF-SS-OCT is able to visualise previously unmeasurably fast changes in the retina, including the propagation of pulse waves. Georg Thieme Verlag KG Stuttgart · New York.

  10. Blood vessels pattern heparan sulfate gradients between their apical and basolateral aspects.

    Directory of Open Access Journals (Sweden)

    Liat Stoler-Barak

    Full Text Available A hallmark of immune cell trafficking is directional guidance via gradients of soluble or surface bound chemokines. Vascular endothelial cells produce, transport and deposit either their own chemokines or chemokines produced by the underlying stroma. Endothelial heparan sulfate (HS was suggested to be a critical scaffold for these chemokine pools, but it is unclear how steep chemokine gradients are sustained between the lumenal and ablumenal aspects of blood vessels. Addressing this question by semi-quantitative immunostaining of HS moieties around blood vessels with a pan anti-HS IgM mAb, we found a striking HS enrichment in the basal lamina of resting and inflamed post capillary skin venules, as well as in high endothelial venules (HEVs of lymph nodes. Staining of skin vessels with a glycocalyx probe further suggested that their lumenal glycocalyx contains much lower HS density than their basolateral extracellular matrix (ECM. This polarized HS pattern was observed also in isolated resting and inflamed microvascular dermal cells. Notably, progressive skin inflammation resulted in massive ECM deposition and in further HS enrichment around skin post capillary venules and their associated pericytes. Inflammation-dependent HS enrichment was not compromised in mice deficient in the main HS degrading enzyme, heparanase. Our results suggest that the blood vasculature patterns steep gradients of HS scaffolds between their lumenal and basolateral endothelial aspects, and that inflammatory processes can further enrich the HS content nearby inflamed vessels. We propose that chemokine gradients between the lumenal and ablumenal sides of vessels could be favored by these sharp HS scaffold gradients.

  11. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Directory of Open Access Journals (Sweden)

    William Ruger Porter

    Full Text Available Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange. Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana was investigated using a differential-contrast, dual-vascular injection (DCDVI technique and high-resolution X-ray microcomputed tomography (μCT. Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory

  12. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Science.gov (United States)

    Porter, William Ruger; Witmer, Lawrence M

    2015-01-01

    Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

  13. An Automatic Cognitive Graph-Based Segmentation for Detection of Blood Vessels in Retinal Images

    Directory of Open Access Journals (Sweden)

    Rasha Al Shehhi

    2016-01-01

    Full Text Available This paper presents a hierarchical graph-based segmentation for blood vessel detection in digital retinal images. This segmentation employs some of perceptual Gestalt principles: similarity, closure, continuity, and proximity to merge segments into coherent connected vessel-like patterns. The integration of Gestalt principles is based on object-based features (e.g., color and black top-hat (BTH morphology and context and graph-analysis algorithms (e.g., Dijkstra path. The segmentation framework consists of two main steps: preprocessing and multiscale graph-based segmentation. Preprocessing is to enhance lighting condition, due to low illumination contrast, and to construct necessary features to enhance vessel structure due to sensitivity of vessel patterns to multiscale/multiorientation structure. Graph-based segmentation is to decrease computational processing required for region of interest into most semantic objects. The segmentation was evaluated on three publicly available datasets. Experimental results show that preprocessing stage achieves better results compared to state-of-the-art enhancement methods. The performance of the proposed graph-based segmentation is found to be consistent and comparable to other existing methods, with improved capability of detecting small/thin vessels.

  14. A Strategy for Rapid Construction of Blood Vessel-Like Structures with Complex Cell Alignments.

    Science.gov (United States)

    Wang, Nuoxin; Peng, Yunhu; Zheng, Wenfu; Tang, Lixue; Cheng, Shiyu; Yang, Junchuan; Liu, Shaoqin; Zhang, Wei; Jiang, Xingyu

    2018-04-17

    A method is developed that can rapidly produce blood vessel-like structures by bonding cell-laden electrospinning (ES) films layer by layer using fibrin glue within 90 min. This strategy allows control of cell type, cell orientation, and material composition in separate layers. Furthermore, ES films with thicker fibers (polylactic-co-glycolic acid, fiber diameter: ≈3.7 µm) are used as cell-seeding layers to facilitate the cell in-growth; those with thinner fibers (polylactic acid, fiber diameter: ≈1.8 µm) are used as outer reinforcing layers to improve the mechanical strength and reduce the liquid leakage of the scaffold. Cells grow, proliferate, and migrate well in the multilayered structure. This design aims at a new type of blood vessel substitute with flexible control of parameters and implementation of functions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

    Directory of Open Access Journals (Sweden)

    Yue Zhang

    2016-05-01

    Full Text Available Since nanoparticles are now widely applied as food additives, in cosmetics and other industries, especially in medical therapy and diagnosis, we ask here whether nanoparticles can cause several adverse effects to human health. In this review, based on research on nanotoxicity, we mainly discuss the negative influence of nanoparticles on blood vessels in several aspects and the potential mechanism for nanoparticles to penetrate endothelial layers of blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs.

  16. Electrospun Fibrous Scaffolds for Small-Diameter Blood Vessels: A Review

    Directory of Open Access Journals (Sweden)

    Nasser K. Awad

    2018-03-01

    Full Text Available Small-diameter blood vessels (SDBVs are still a challenging task to prepare due to the occurrence of thrombosis formation, intimal hyperplasia, and aneurysmal dilation. Electrospinning technique, as a promising tissue engineering approach, can fabricate polymer fibrous scaffolds that satisfy requirements on the construction of extracellular matrix (ECM of native blood vessel and promote the adhesion, proliferation, and growth of cells. In this review, we summarize the polymers that are deployed for the fabrication of SDBVs and classify them into three categories, synthetic polymers, natural polymers, and hybrid polymers. Furthermore, the biomechanical properties and the biological activities of the electrospun SBVs including anti-thrombogenic ability and cell response are discussed. Polymer blends seem to be a strategic way to fabricate SDBVs because it combines both suitable biomechanical properties coming from synthetic polymers and favorable sites to cell attachment coming from natural polymers.

  17. A SURVEY OF RETINA BASED DISEASE IDENTIFICATION USING BLOOD VESSEL SEGMENTATION

    Directory of Open Access Journals (Sweden)

    P Kuppusamy

    2016-11-01

    Full Text Available The colour retinal photography is one of the most essential features to identify the confirmation of various eye diseases. The iris is primary attribute to authenticate the human. This research work presents the survey and comparison of various blood vessel related feature identification, segmentation, extraction and enhancement methods. Additionally, this study is observed the various databases performance for storing the images and testing in minimal time. This paper is also provides the better performance techniques based on the survey.

  18. Heat as a contrast agent to enhance thermal imaging of blood vessels

    Science.gov (United States)

    Case, Jason R.; Trammell, Susan R.; Young, Madison A.; Israel, Uriah; Crown, Michael X.

    2013-03-01

    In this study we test the feasibility of using low-cost LEDs to selectivity heat blood for enhanced thermal imaging of vascular structures. Applications of this new imaging technique include mapping blood vessels during surgeries such as tumor removal and vascular repair. In addition, this technique could potentially be used to determine the location of increased vascular density, and thus breast cancer tumors. Porcine blood, skeletal muscle, skin and fat were illuminated with LEDs that emit at 405 nm and 530 nm (near the blood absorption peaks) and the increase in temperature as a function of time was recorded using a thermal camera. In the studies with the 530 nm LED, blood heated more than other tissue types and the heating rate for the blood was significantly faster than other tissues. Illumination of blood with the 530 nm LED at low powers (tissue irradiance tissue. Illumination with the 405 nm LED produced large temperature changes (up to 15°C) at low LED powers (tissue irradiance muscle tissue was dependent on the skeletal muscle type, but most samples showed heating comparable to or larger than blood. This LED was not effective at selectively heating blood relative to the other tissue types. The results of the preliminary studies suggest that the best contrast can be achieved with pulsed 530 nm LED illumination and an image analysis method that highlights rapid changes in temperature.

  19. Factors governing the healing of Staphylococcus aureus infections following hip and knee prosthesis implantation: a retrospective study of 95 patients.

    Science.gov (United States)

    Joulie, D; Girard, J; Mares, O; Beltrand, E; Legout, L; Dezèque, H; Migaud, H; Senneville, E

    2011-11-01

    The prognostic factors for total hip arthroplasty (THA) and total knee arthroplasty (TKA) Staphylococcus aureus prosthetic joint infections are poorly known, notably because of the heterogeneous management in terms of both antibiotic administration and adopted surgical strategy. Uniform treatment regimens would make it easier to define the outcome of these S. aureus infections. Between 2001 and 2006, 95 patients with a S. aureus joint infection after THA or TKA were treated, strictly following a standardized protocol according to the recommendations of Zimmerli et al. The patients' mean age was 65.7 years, 71 with THA and 28 with TKA (four patients had two infected joints). These 95 patients presented 120 infectious episodes, all of whom had surgical treatment: 53 lavages (44.1%), 17 one-stage prosthesis revisions (14.2%), 29 two-stage prosthesis revisions (24.2%), and 21 prostheses removed (17.5%). On the intraoperative samples taken, methicillin-sensitive S. aureus (MSSA) was isolated in 88 patients (73.3%) and methicillin-resistant S. aureus (MRSA) in 18 patients (15%); finally 14 patients were included because of the positive results of preoperative samples taken. Twenty-seven infections (22.5%) were multibacterial, including at least S. aureus and 93 were single S. aureus bacteria. Success was defined at a minimum 12 months of follow-up by the association of the following parameters: normal erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) results, noninflammatory scar with no fistula, no surgical revision, and no antibiotic treatment. At a mean follow-up of 38±24.9 months, 81 of the 120 infectious episodes were resolved (67.5%) and 77 of the 95 patients were healed (81%). Six parameters significantly influenced the healing of the infection: initial cementless fixation, THA, preoperative knowledge of the bacterium, immediate postoperative antibiotic therapy adapted to the microbiological data, changing the prosthesis, and monobacterial

  20. Esthetic Outcome of Implant Supported Crowns With and Without Peri-Implant Conditioning Using Provisional Fixed Prosthesis: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Furze, David; Byrne, Ashley; Alam, Sonia; Wittneben, Julia-Gabriela

    2016-12-01

    Achieving an optimal esthetic result using dental implants is challenging. Fixed implant-supported provisional crowns are often used to customize the emergence profile and to individualize the surrounding peri-implant soft tissue. The objective of this study is to evaluate whether the use of a provisional implant-supported crown leads to an esthetic benefit on implants that are placed in the esthetic zone. The null hypothesis is that there is no-difference between the two study groups. Twenty single implants (Bone Level, Straumann AG, Basel, Switzerland) were inserted in consecutive patients. After reopening, a randomization process assigned them to either cohort group 1: a provisional phase with soft tissue conditioning using the "dynamic compression technique" or cohort group 2: without a provisional. Implants were finally restored with an all-ceramic crown. Follow-up examinations were performed at 3 and 12 months including implant success and survival, clinical, and radiographic parameters. After 1 year all implants successfully integrated, mean values of combined modPES and WES were 16.7 for group 1 and 10.5 for Group 2. This was statistically significant. Mean bone loss after 1 year was -0.09 and -0.08 for groups 1 and 2, respectively, without being statistically significant. A provisional phase with soft tissue conditioning does improve the final esthetic result. © 2016 Wiley Periodicals, Inc.

  1. Management of an Infected Nonunion of an Opening-Wedge High Tibial Osteotomy with 2-Stage Implantation of Rotating Hinge Knee Prosthesis

    Directory of Open Access Journals (Sweden)

    Sandrine Mariaux

    2018-01-01

    Full Text Available Introduction. High tibial osteotomy (HTO is a frequent and effective treatment for unicompartmental gonarthritis. Only a few articles are focused on the treatment of infected nonunion. Patient and Method. A 50-year-old obese patient was operated on by medial opening-wedge HTO. She developed a painful nonunion treated by hardware removal, allograft, and plate fixation. However, the nonunion persisted. 2 years later, cellulitis appeared with an abscess adjacent to the HTO plate. Despite surgical debridement and antibiotics, septic knee arthritis occurred. In a situation of infected nonunion and septic arthritis with chondrolysis, she was scheduled for a 2-stage total knee replacement (TKR. The infected tibial articular block was first resected and replaced by a cement spacer. After a short interval, the TKR was implanted. After 2 years, the patient walked pain-free with good knee function. Discussion. In the literature, different efficient treatments exist for infected nonunion after HTO, but comprehensive studies are missing for a consensus treatment. Current data are mostly based on case reports, since this pathology is quite rare. Conclusion. In a difficult situation of infected nonunion with septic knee arthritis, we performed a 2-stage knee prosthesis implantation. This led to an early mobilization and fast recovery.

  2. [Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study].

    Science.gov (United States)

    Szarpak, Łukasz; Kurowski, Andrzej

    2014-01-01

    Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological materials. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vessels under simulated resuscitation, were analyzed. Gloves were tested by the water leak test. The water test revealed 44 cases of damage to the gloves used during cannulation of blood vessels. Significant differences were noted in the frequency of damage to both the outer and single pairs of gloves and the inner pair of gloves. The study showed that the use of double gloves provides a higher level of security for a paramedic than the use of a single pair of gloves, however, double gloves reduce the manual dexterity of a paramedic. A large number of damages to gloves are not noticed by medical personnel during surgery.

  3. Effect of Electrical Stimulation on Blood Flow Velocity and Vessel Size

    Science.gov (United States)

    Jin, Hee-Kyung; Hwang, Tae-Yeon; Cho, Sung-Hyoun

    2017-01-01

    Abstract Interferential current electrical stimulation alters blood flow velocity and vessel size. We aimed to investigate the changes in the autonomic nervous system depending on electrical stimulation parameters. Forty-five healthy adult male and female subjects were studied. Bipolar adhesive pad electrodes were used to stimulate the autonomic nervous system at the thoracic vertebrae 1-4 levels for 20 min. Using Doppler ultrasonography, blood flow was measured to determine velocity and vessel size before, immediately after, and 30 min after electrical stimulation. Changes in blood flow velocity were significantly different immediately and 30 min after stimulation. The interaction between intervention periods and groups was significantly different between the exercise and pain stimulation groups immediately after stimulation (p<0.05). The vessel size was significantly different before and 30 min after stimulation (p<0.05). Imbalances in the sympathetic nervous system, which regulates balance throughout the body, may present with various symptoms. Therefore, in the clinical practice, the parameters of electrical stimulation should be selectively applied in accordance with various conditions and changes in form. PMID:28401194

  4. Promoting blood vessel growth in ischemic diseases: challenges in translating preclinical potential into clinical success

    Directory of Open Access Journals (Sweden)

    Galina Dragneva

    2013-03-01

    Full Text Available Angiogenic therapy, which involves the use of an exogenous stimulus to promote blood vessel growth, is an attractive approach for the treatment of ischemic diseases. It has been shown in animal models that the stimulation of blood vessel growth leads to the growth of the whole vascular tree, improvement of ischemic tissue perfusion and improved muscle aerobic energy metabolism. However, very few positive results have been gained from Phase 2 and 3 clinical angiogenesis trials. Many reasons have been given for the failures of clinical trials, including poor transgene expression (in gene-therapy trials and instability of the vessels induced by therapy. In this Review, we discuss the selection of preclinical models as one of the main reasons why clinical translation has been unsuccessful thus far. This issue has received little attention, but could have had dramatic implications on the expectations of clinical trials. We highlight crucial differences between human patients and animal models with regards to blood flow and pressure, as well as issues concerning the chronic nature of ischemic diseases in humans. We use these as examples to demonstrate why the results from preclinical trials might have overestimated the efficacy of angiogenic therapies developed to date. We also suggest ways in which currently available animal models of ischemic disease could be improved to better mimic human disease conditions, and offer advice on how to work with existing models to avoid overestimating the efficacy of new angiogenic therapies.

  5. Effect of Electrical Stimulation on Blood Flow Velocity and Vessel Size.

    Science.gov (United States)

    Jin, Hee-Kyung; Hwang, Tae-Yeon; Cho, Sung-Hyoun

    2017-01-01

    Interferential current electrical stimulation alters blood flow velocity and vessel size. We aimed to investigate the changes in the autonomic nervous system depending on electrical stimulation parameters. Forty-five healthy adult male and female subjects were studied. Bipolar adhesive pad electrodes were used to stimulate the autonomic nervous system at the thoracic vertebrae 1-4 levels for 20 min. Using Doppler ultrasonography, blood flow was measured to determine velocity and vessel size before, immediately after, and 30 min after electrical stimulation. Changes in blood flow velocity were significantly different immediately and 30 min after stimulation. The interaction between intervention periods and groups was significantly different between the exercise and pain stimulation groups immediately after stimulation (p<0.05). The vessel size was significantly different before and 30 min after stimulation (p<0.05). Imbalances in the sympathetic nervous system, which regulates balance throughout the body, may present with various symptoms. Therefore, in the clinical practice, the parameters of electrical stimulation should be selectively applied in accordance with various conditions and changes in form.

  6. Dual-body magnetic helical robot for drilling and cargo delivery in human blood vessels

    Science.gov (United States)

    Lee, Wonseo; Jeon, Seungmun; Nam, Jaekwang; Jang, Gunhee

    2015-05-01

    We propose a novel dual-body magnetic helical robot (DMHR) manipulated by a magnetic navigation system. The proposed DMHR can generate helical motions to navigate in human blood vessels and to drill blood clots by an external rotating magnetic field. It can also generate release motions which are relative rotational motions between dual-bodies to release the carrying cargos to a target region by controlling the magnitude of an external magnetic field. Constraint equations were derived to selectively manipulate helical and release motions by controlling external magnetic fields. The DMHR was prototyped and various experiments were conducted to demonstrate its motions and verify its manipulation methods.

  7. Note: Reflection-type micro multipoint laser Doppler velocimeter for measuring velocity distributions in blood vessels.

    Science.gov (United States)

    Ishida, H; Kobayashi, D; Shirakawa, H; Andoh, T; Akiguchi, S; Wakisaka, T; Ishizuka, M; Hachiga, T

    2011-07-01

    We have developed a laser Doppler velocimeter (LDV) for measuring velocity distributions in blood vessels. We converted a transmission-based LDV into a reflection-based LDV to make it suitable for clinical applications. The velocity distribution image of a serpentine flow channel obtained could be qualitatively explained by the numerical results. Finally, we evaluated the system by using it to measure injection of blood into a glass tube by a syringe pump. The results obtained demonstrate that erythrocytes can be used as seeding particles for the reflection-type micro multipoint LDV. The results obtained are useful as basic data for clinical applications.

  8. Microstructured Blood Vessel Surrogates Reveal Structural Tropism of Motile Malaria Parasites.

    Science.gov (United States)

    Muthinja, Mendi J; Ripp, Johanna; Hellmann, Janina K; Haraszti, Tamas; Dahan, Noa; Lemgruber, Leandro; Battista, Anna; Schütz, Lucas; Fackler, Oliver T; Schwarz, Ulrich S; Spatz, Joachim P; Frischknecht, Friedrich

    2017-03-01

    Plasmodium sporozoites, the highly motile forms of the malaria parasite, are transmitted naturally by mosquitoes and traverse the skin to find, associate with, and enter blood capillaries. Research aimed at understanding how sporozoites select blood vessels is hampered by the lack of a suitable experimental system. Arrays of uniform cylindrical pillars can be used to study small cells moving in controlled environments. Here, an array system displaying a variety of pillars with different diameters and shapes is developed in order to investigate how Plasmodium sporozoites associate to the pillars as blood vessel surrogates. Investigating the association of sporozoites to pillars in arrays displaying pillars of different diameters reveals that the crescent-shaped parasites prefer to associate with and migrate around pillars with a similar curvature. This suggests that after transmission by a mosquito, malaria parasites may use a structural tropism to recognize blood capillaries in the dermis in order to gain access to the blood stream. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The Emergence of Blood and Blood Vessels in the Embryo and Its Relevance to Postnatal Biology and Disease

    Science.gov (United States)

    Sills, Tiffany M.; Hirschi, Karen K.

    Blood and blood vessels develop in parallel within mammalian systems, and this temporal and spatial association has led to the confirmation of an endothelial origin of hematopoiesis. The extraembryonic yolk sac and aorto-gonado-mesonephros (AGM) region both contain a specialized population of endothelial cells ("hemogenic endothelium") that function to produce hematopoietic stem and progenitor cells, which then differentiate to provide the full complement of blood cells within the developing embryo and furthermore in the adult system. Therefore, this population has great therapeutic potential in the fields of regenerative medicine and tissue engineering. This chapter reviews the development of the vascular and hematopoietic systems, characterization and function of the hemogenic endothelium within embryonic and embryonic stem cell (ES cell) models, and speculate on the presence of such a population within the adult system. In order to harness this endothelial subtype for clinical application, we must understand both the normal functions of these cells and the potential for misregulation in disease states.

  10. Immediately Loaded Intraorally Welded Complete-Arch Maxillary Provisional Prosthesis.

    Science.gov (United States)

    Albiero, Alberto Maria; Benato, Renato; Fincato, Andrea

    2015-01-01

    Guided implant surgery is not completely accurate when using computer-designed stereolithographic surgical guides. Complications are frequently reported when combining computer-guided flapless surgery with an immediately loaded prefabricated prosthesis. Achieving passive fit of a prefabricated prosthesis on the inserted implants the same day of the surgery can be difficult. The aim of this report is to show a new treatment approach to immediately loaded implants inserted with computer-guided surgery using an intraoral welded full-arch provisional prosthesis.

  11. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    Directory of Open Access Journals (Sweden)

    Fenglin Song

    2014-01-01

    Full Text Available To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV were less than those in the control group (using Gore-Tex. The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility.

  12. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    Science.gov (United States)

    Song, Fenglin; Zhou, Wenwu; Tang, Tao; Li, Xiaobing; Wu, Xiaoming; Yang, Jinfu

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV) were less than those in the control group (using Gore-Tex). The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility. PMID:24696856

  13. An experimental study to replace the thoracic descending aorta for pigs with a self-made sutureless blood vessel.

    Science.gov (United States)

    Song, Fenglin; Zhou, Wenwu; Tang, Tao; Li, Xiaobing; Wu, Xiaoming; Yang, Jinfu

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV) were less than those in the control group (using Gore-Tex). The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility.

  14. Prosthesis-patient mismatch after transcatheter aortic valve implantation: impact of 2D-transthoracic echocardiography versus 3D-transesophageal echocardiography.

    Science.gov (United States)

    da Silva, Cristina; Sahlen, Anders; Winter, Reidar; Bäck, Magnus; Rück, Andreas; Settergren, Magnus; Manouras, Aristomenis; Shahgaldi, Kambiz

    2014-12-01

    To investigate the role of 2D-transthoracic echocardiography (2D-TTE) and 3D-transesophageal echocardiography (3D-TEE) in the determination of aortic annulus size prior transcatheter aortic valve implantation (TAVI) and its' impact on the prevalence of patient prosthesis mismatch (PPM). Echocardiography plays an important role in measuring aortic annulus dimension in patients undergoing TAVI. This has great importance since it determines both eligibility for TAVI and selection of prosthesis type and size, and can be potentially important in preventing an inadequate ratio between the prosthetic valvular orifice and the patient's body surface area, concept known as prosthesis-patient mismatch (PPM). A total of 45 patients were studied pre-TAVI: 20 underwent 3D-TEE (men/women 12/8, age 84.8 ± 5.6) and 25 2D-TTE (men/women 9/16, age 84.4 ± 5.4) in order to measure aortic annulus diameter. The presence of PPM was assessed before hospital discharge and after a mean period of 3 months. Moderate PPM was defined as indexed aortic valve area (AVAi) ≤ 0.85 cm(2)/m(2) and severe PPM as AVAi < 0.65 cm(2)/m(2). Immediately post-TAVI, moderate PPM was present in 25 and 28 % of patients worked up using 3D-TEE and 2D-TTE respectively p value = n.s) and severe PPM occurred in 10 % of the patients who underwent 3D-TEE and in 20 % in those with 2D-TTE (p value = n.s). The echocardiographic evaluation 3 months post-TAVI showed 25 % moderate PPM in the 3D-TEE group compared with 24 % in the 2D-TTE group (p value = n.s) and no cases of severe PPM in the 3DTEE group comparing to 20 % in the 2D-TTE group (p = 0.032). Our results indicate a higher incidence of severe PPM in patients who performed 2DTTE compared to those performing 3DTEE prior TAVI. This suggests that the 3D technique should replace the 2DTTE analysis when investigating the aortic annulus diameter in patients undergoing TAVI.

  15. Effect of type of luting agents on stress distribution in the bone surrounding implants supporting a three-unit fixed dental prosthesis: 3D finite element analysis

    Science.gov (United States)

    Ghasemi, Ehsan; Abedian, Alireza; Iranmanesh, Pedram; Khazaei, Saber

    2015-01-01

    Background: Osseointegration of dental implants is influenced by many biomechanical factors that may be related to stress distribution. The aim of this study was to evaluate the effect of type of luting agent on stress distribution in the bone surrounding implants, which support a three-unit fixed dental prosthesis (FDP) using finite element (FE) analysis. Materials and Methods: A 3D FE model of a three-unit FDP was designed replacing the maxillary first molar with maxillary second premolar and second molar as the abutments using CATIA V5R18 software and analyzed with ABAQUS/CAE 6.6 version. The model was consisted of 465108 nodes and 86296 elements and the luting agent thickness was considered 25 μm. Three load conditions were applied on eight points in each functional cusp in horizontal (57.0 N), vertical (200.0 N) and oblique (400.0 N, θ = 120°) directions. Five different luting agents were evaluated. All materials were assumed to be linear elastic, homogeneous, time independent and isotropic. Results: For all luting agent types, the stress distribution pattern in the cortical bone, connectors, implant and abutment regions was almost uniform among the three loads. Furthermore, the maximum von Mises stress of the cortical bone was at the palatal side of second premolar. Likewise, the maximum von Mises stress in the connector region was in the top and bottom of this part. Conclusion: Luting agents transfer the load to cortical bone and different types of luting agents do not affect the pattern of load transfer. PMID:25709676

  16. The Ibero-American transcatheter aortic valve implantation registry with the CoreValve prosthesis. Early and long-term results.

    Science.gov (United States)

    Muñoz-García, Antonio J; del Valle, Raquel; Trillo-Nouche, Ramiro; Elízaga, Jaime; Gimeno, Federico; Hernández-Antolín, Rosana; Teles, Rui; de Gama Ribeiro, Vasco; Molina, Eduardo; Cequier, Angel; Urbano-Carrillo, Cristóbal; Cruz-González, Ignacio; Payaslian, Miguel; Patricio, Lino; Sztejfman, Matías; Iñiguez, Andrés; Rodríguez, Víctor; Scuteri, Antonio; Caorsi, Carlos; López-Otero, Diego; Avanzas, Pablo; Alonso-Briales, Juan H; Hernández-García, José M; Morís, César

    2013-11-20

    Transcatheter aortic valve implantation (TAVI) is the recommended therapy for patients with severe aortic stenosis who are not suitable candidates for surgery. The aim of this study was to describe early experience and long-term follow-up with the CoreValve self-expanding aortic prosthesis at 42 Ibero-American hospitals. Multiple centre observational study including 1220 consecutive patients with symptomatic severe aortic stenosis who are not suitable candidates for surgery and underwent transcatheter aortic valve implantation with the self-expanding Medtronic CoreValve System between December 2007 and May 2012. The registry included 1220 consecutive patients with a mean age of 80.8 ± 6.3 years and a mean logistic euroSCORE of 17.8% ± 13%. The procedural success rate was 96.1%. Hospital mortality was 7.3% and combined end-point was 21.3%. Aortic regurgitation after TAVI was present in 24.5% (Sellers grade ≥ 2). The estimated 1-year and 2-year survival rates were 82.1% and 73.4% respectively. The following issues were significant independent risk factors for hospital mortality: acute kidney failure (odds ratio 3.55); stroke (odds ratio 5.72); major bleeding (odds ratio 2.64) and euroSCORE (odds ratio 1.02). Long-term predictors of mortality were diabetes mellitus (hazard ratio 1.59, 95% confidence interval 1.09-2.31), severe chronic obstructive pulmonary disease (hazard ratio 1.85, 95% confidence interval 1.85-2.88), and functional classes NYHA III-IV (hazard ratio 1.31, 95% confidence interval 1.01-1.70). Transcatheter aortic valve implantation constitutes a safe and viable therapeutic option for high operative risk patients with severe aortic stenosis. Long-term prognosis is conditioned by associate comorbidities. © 2013.

  17. [Survivorship of the cemented hip prosthesis].

    Science.gov (United States)

    Kaczmarek, Wiesław; Ceglarz, Przemysław; Kucharski, Jakub; Pietrzak, Krzysztof; Pucher, Andrzej

    2010-01-01

    To asses a survival-time of the cemented hip prostheses and to find factors causing its loosening. 211 patients (282 hip prostheses) were analyzed, of the 1693 patients (2096 hip prostheses) treated between 1970-2000. The follow-up ranged from 7 to 34 years (mean: 12.2 ++/- 5.4 years). The age of the patients at the operation procedure ranged from 25 to 74 years (mean 52 +/- 12 years). Only aseptic prosthesis loosening were considered and Kaplan-Meyer method was used for the prosthesis survivorship assessment. Of the 282 prostheses, implant exchange was performed in 39 cases, where in 15 cases only cup was revised, in 5 cases the stem exclusively, and in 19 patients the whole implant was exchanged. Only 1.1% of implants were exchanged during first 5 years after surgery but from the 6th year the percentage of loosening increased several percents each year. Respectively 88.6, 70 and 65% survivorship of prosthesis was found after 10, 15, 20 years of follow-up. In the group of bilateral prosthesis implantation, the first implanted prosthesis was more susceptible for loosening. Seven cases of aseptic loosening (5.4%) of the 129 prostheses implanted between 1974 and 1995, occurred within 7 years after initial surgery where only one prosthesis (0.7%) was revised of the 152 implanted between 1996-2000 in the same time of follow-up. The age, growth, weight, BMI and sex did not influence the risk of implant loosening. The mean survivorship of the hip prosthesis is 65% in 20- years follow up. When a proper initial fixation of the cemented hip prosthesis is performed, the risk of implant loosening increases gradually especially from the 6th year after surgery. The modern implants are less susceptible for loosening.

  18. Mammalian Cardiovascular Patterning as Determined by Hemodynamic Forces and Blood Vessel Genetics

    Science.gov (United States)

    Anderson, Gregory Arthur

    Cardiovascular development is a process that involves the timing of multiple molecular events, and numerous subtle three-dimensional conformational changes. Traditional developmental biology techniques have provided large quantities of information as to how these complex organ systems develop. However, the major drawback of the majority of current developmental biological imaging is that they are two-dimensional in nature. It is now well recognized that circulation of blood is required for normal patterning and remodeling of blood vessels. Normal blood vessel formation is dependent upon a complex network of signaling pathways, and genetic mutations in these pathways leads to impaired vascular development, heart failure, and lethality. As such, it is not surprising that mutant mice with aberrant cardiovascular patterning are so common, since normal development requires proper coordination between three systems: the heart, the blood, and the vasculature. This thesis describes the implementation of a three-dimensional imaging technique, optical projection tomography (OPT), in conjunction with a computer-based registration algorithm to statistically analyze developmental differences in groups of wild-type mouse embryos. Embryos that differ by only a few hours' gestational time are shown to have developmental differences in blood vessel formation and heart development progression that can be discerned. This thesis describes how we analyzed mouse models of cardiovascular perturbation by OPT to detect morphological differences in embryonic development in both qualitative and quantitative ways. Both a blood vessel specific mutation and a cardiac specific mutation were analyzed, providing evidence that developmental defects of these types can be quantified. Finally, we describe the implementation of OPT imaging to identify statistically significant phenotypes from three different mouse models of cardiovascular perturbation across a range of developmental time points. Image

  19. Prosthetic rehabilitation with an implant-supported fixed prosthesis using computer-aided design and computer-aided manufacturing dental technology for a patient with a mandibulectomy: A clinical report.

    Science.gov (United States)

    Yoon, Hyung-In; Han, Jung-Suk

    2016-02-01

    The fabrication of dental prostheses with computer-aided design and computer-aided manufacturing shows acceptable marginal fits and favorable treatment outcomes. This clinical report describes the management of a patient who had undergone a mandibulectomy and received an implant-supported fixed prosthesis by using additive manufacturing for the framework and subtractive manufacturing for the monolithic zirconia restorations. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  20. Adaptable three-dimensional Monte Carlo modeling of imaged blood vessels in skin

    Science.gov (United States)

    Pfefer, T. Joshua; Barton, Jennifer K.; Chan, Eric K.; Ducros, Mathieu G.; Sorg, Brian S.; Milner, Thomas E.; Nelson, J. Stuart; Welch, Ashley J.

    1997-06-01

    In order to reach a higher level of accuracy in simulation of port wine stain treatment, we propose to discard the typical layered geometry and cylindrical blood vessel assumptions made in optical models and use imaging techniques to define actual tissue geometry. Two main additions to the typical 3D, weighted photon, variable step size Monte Carlo routine were necessary to achieve this goal. First, optical low coherence reflectometry (OLCR) images of rat skin were used to specify a 3D material array, with each entry assigned a label to represent the type of tissue in that particular voxel. Second, the Monte Carlo algorithm was altered so that when a photon crosses into a new voxel, the remaining path length is recalculated using the new optical properties, as specified by the material array. The model has shown good agreement with data from the literature. Monte Carlo simulations using OLCR images of asymmetrically curved blood vessels show various effects such as shading, scattering-induced peaks at vessel surfaces, and directionality-induced gradients in energy deposition. In conclusion, this augmentation of the Monte Carlo method can accurately simulate light transport for a wide variety of nonhomogeneous tissue geometries.

  1. A simply prepared small-diameter artificial blood vessel that promotes in situ endothelialization.

    Science.gov (United States)

    Guo, Hong-Feng; Dai, Wei-Wei; Qian, De-Hui; Qin, Zhe-Xue; Lei, Yan; Hou, Xiao-Yu; Wen, Can

    2017-05-01

    Synthetic grafts are of limited use in small-diameter vessels (Φartificial blood vessels with the aim of facilitating early endothelialization and improving long-term patency. STATEMENT OF SIGNIFICANCE: (1) SDF-1α/VEGF loaded PU conduits were simply prepared by electrospinning. The cytokines with definite and potent effects on angiogenesis were used to avoid complicated mechanism researches. Compared with most of the current vascular grafts which are of poor strength or elasticity, the conduits have favorable mechanical property. All of these inhibit the conduits from occlusion, and thus improve their long-term patency rate. (2) For the in vivo tests, the dogs did not receive any anticoagulant medication in the follow-up period to expose the grafts to the strictest conditions. In vivo endothelialization of the conduits was thoroughly investigated by Sonography, HE staining, SEM and LSCM. The study will be helpful for the construction of small-diameter artificial blood vessels. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  2. Blood Vessel Extraction in Color Retinal Fundus Images with Enhancement Filtering and Unsupervised Classification

    Directory of Open Access Journals (Sweden)

    Zafer Yavuz

    2017-01-01

    Full Text Available Retinal blood vessels have a significant role in the diagnosis and treatment of various retinal diseases such as diabetic retinopathy, glaucoma, arteriosclerosis, and hypertension. For this reason, retinal vasculature extraction is important in order to help specialists for the diagnosis and treatment of systematic diseases. In this paper, a novel approach is developed to extract retinal blood vessel network. Our method comprises four stages: (1 preprocessing stage in order to prepare dataset for segmentation; (2 an enhancement procedure including Gabor, Frangi, and Gauss filters obtained separately before a top-hat transform; (3 a hard and soft clustering stage which includes K-means and Fuzzy C-means (FCM in order to get binary vessel map; and (4 a postprocessing step which removes falsely segmented isolated regions. The method is tested on color retinal images obtained from STARE and DRIVE databases which are available online. As a result, Gabor filter followed by K-means clustering method achieves 95.94% and 95.71% of accuracy for STARE and DRIVE databases, respectively, which are acceptable for diagnosis systems.

  3. Mechanical Failure of Revision Knee Prosthesis at both Femoral and Tibial Modular Metaphyseal Stem Junctions.

    Science.gov (United States)

    Woodgate, Ian G; Rooney, John; Mulford, Johnathan S; Gillies, R Mark

    2016-01-01

    This is a report of a mechanical failure of an S-ROM revision total knee prosthesis. The prosthesis was used as a revision implant following deep peri-prosthetic infection in a morbidly obese male. The prosthesis failed on both the femoral and tibial sides at the modular metaphyseal stem junctions and required a further revision using the same type of implant after infection was excluded. A 57 year old male had previously undergone a left total knee arthroplasty in 1999 for osteoarthritis. He acquired a late deep peri-prosthetic infection with a multi-resistant Staphylococcus epidermidis. The organism was sensitive to vancomycin and rifampicin. A two stage revision was undertaken after clinical signs of infection had resolved and blood parameters had normalized. Intra-operative gram stain was negative for micro-organisms and frozen section of deep tissue was less than five polymorphs per high power field. A cemented S-ROM prosthesis was implanted using a coronal tibial osteotomy and a lateral release for exposure. After three years of the second stage of revision, the patient again presented to the orthopaedic department after reportedly falling on a wet floor six weeks ago. Radiographically, there was a broken tibial wire, osteolysis and pedestal formation around both the femoral and distal tibial stem extensions. The prosthesis was bent at the proximal tibial sleeve and stem junction. The prosthesis was considered loose with mechanical failure. At implant removal, it was noted that the femoral and tibial components at the modular metaphyseal sleeve-stem junction were fractured. Surgeons should be cautious in the use of these implants in morbidly obese patients where the stresses generated maybe above the yield stress of the material and the frictional forces that may overcome the modular taper junction's locking mechanism.

  4. High Endothelial Venules and Other Blood Vessels: Critical Regulators of Lymphoid Organ Development and Function

    Science.gov (United States)

    Ager, Ann

    2017-01-01

    The blood vasculature regulates both the development and function of secondary lymphoid organs by providing a portal for entry of hemopoietic cells. During the development of lymphoid organs in the embryo, blood vessels deliver lymphoid tissue inducer cells that initiate and sustain the development of lymphoid tissues. In adults, the blood vessels are structurally distinct from those in other organs due to the requirement for high levels of lymphocyte recruitment under non-inflammatory conditions. In lymph nodes (LNs) and Peyer’s patches, high endothelial venules (HEVs) especially adapted for lymphocyte trafficking form a spatially organized network of blood vessels, which controls both the type of lymphocyte and the site of entry into lymphoid tissues. Uniquely, HEVs express vascular addressins that regulate lymphocyte entry into lymphoid organs and are, therefore, critical to the function of lymphoid organs. Recent studies have demonstrated important roles for CD11c+ dendritic cells in the induction, as well as the maintenance, of vascular addressin expression and, therefore, the function of HEVs. Tertiary lymphoid organs (TLOs) are HEV containing LN-like structures that develop inside organized tissues undergoing chronic immune-mediated inflammation. In autoimmune lesions, the development of TLOs is thought to exacerbate disease. In cancerous tissues, the development of HEVs and TLOs is associated with improved patient outcomes in several cancers. Therefore, it is important to understand what drives the development of HEVs and TLOs and how these structures contribute to pathology. In several human diseases and experimental animal models of chronic inflammation, there are some similarities between the development and function of HEVs within LN and TLOs. This review will summarize current knowledge of how hemopoietic cells with lymphoid tissue-inducing, HEV-inducing, and HEV-maintaining properties are recruited from the bloodstream to induce the development and

  5. Comparison between PVHIS on the MRI and the permeability of brain blood vessels in elderly patients

    International Nuclear Information System (INIS)

    Yamaguchi, Katsuhiko; Tanaka, Yuriko; Kubo, Hideki; Takagi, Yasushi; Tachikawa, Shinzo; Katsunuma, Hideyo.

    1989-01-01

    The degree of PVHIS (periventricular high intensity signal) on the MRI was composed with the permeability of brain blood vessels using the cerebrospinal fluid (CSF)/serum ratio for albumin, and the CSF/serum ratio for IgG in elderly patients. The 47 elderly patients (mean age=79.9) were divided into three groups: (1) Mild group (20 cases, M:6, F:14, mean age=75.8), (2) Moderate group (18 cases, M:7, F:11, mean age=82.6), (3) Severe group (9 cases, M:2, F:7, mean age=82.9), in accordance with the degree of PVHIS on the MRI. The MRI was operated at a field strength of 0.22 tesla. The pulse sequence (used on all patients) had a repetition times (TR) of 2,000 msec and a time to echo (TE) of 40 msec. The levels of albumin and IgG in the serum and CSF were measured. The CSF/serum ratio for albumin was used of analyze the permeability of the brain blood vessels in each group. There was no significant difference in the level of the serum albumin, the CSF albumin, the serum IgG, the CSF IgG and the CSF/serum ratio for IgG among the three groups. The same was found to be true for the IgG index which indicates the synthesis of immunoglobulin in the central nervous system. However, there was a statistically significant difference (p<0.05) in the CSF/serum ratio for albumin between groups (1) and (3). The increased CSF/serum ratio for albumin in the severe group indicated there were confluent lesions involving the entire extent of the periventriular white matter on the MRI. This suggested an increased permeability of brain blood vessels which revealed the dysfunction of the blood brain barrier due to affected cerebral endothelial cells in capillaries. (author)

  6. The PICS Technique: A Novel Approach for Residual Curvature Correction During Penile Prosthesis Implantation in Patients With Severe Peyronie's Disease Using the Collagen Fleece TachoSil.

    Science.gov (United States)

    Hatzichristodoulou, Georgios

    2018-03-01

    Correction of residual curvature during inflatable penile prosthesis (IPP) implantation in patients with Peyronie's disease (PD) by plaque incision and grafting is a common approach. To present a novel technique for residual curvature correction during IPP implantation using collagen fleece (TachoSil, Baxter Healthcare Corp, Deerfield, IL, USA). After the IPP (Titan Touch, Coloplast, Minneapolis, MN, USA) is placed, the implant is inflated maximally. When residual curvature exceeds 40°, the PICS (penile implant in combination with the Sealing technique) technique is performed. The device is deflated, and a circumcising skin incision and penile degloving are performed. After elevation of the neurovascular bundle, the device is reinflated maximally. Plaque incision is performed at the point of maximum curvature using electrocautery. This leads to penile straightening because the tension is removed. In the next step, the defect of the tunica is closed with collagen fleece, which sticks to the tunica and defect without any sutures needed. The neurovascular bundle is reapproximated and the Buck fascia is closed. This is followed by closure of penile skin. Primary outcome measurements were straightening rates, operative times, 5-item International Index of Erectile Function (IIEF-5) scores at follow-up, immediate and late complications, and patient satisfaction. The PICS technique was applied to 15 patients. Mean patient age was 61.7 years (52-79 years). Mean residual curvature after IPP was 66.7° (50-90°). Mean operative time was 117.3 minutes (100-140 minutes). Mean follow-up was 15.1 months (1-29 months). 12 of 15 patients (80%) showed a totally straight penis. 3 patients (20%) had residual curvature of 10° at follow-up, which did not interfere with sexual intercourse. Mean IIEF-5 score at follow-up was 24.2 (22-25). No immediate or late complications occurred. All patients were satisfied with the surgical outcomes. This novel technique prevents puncture or

  7. Training on insertion and retrieval of optional inferior vena cava filters for interventional radiologists with little or just some experience with the combined use of blood vessel and animal models.

    Science.gov (United States)

    Yamagami, Takuji; Hasebe, Terumitsu; Yoshimatsu, Rika; Matsumoto, Tomohiro; Hashimoto, Takeshi; Komemushi, Atsushi; Kamei, Seiji; Hagihara, Makiyo; Sato, Yozo; Kondo, Hiroshi; Inoue, Masanori; Nakatsuka, Atsuhiro; Takahashi, Makoto; Koizumi, Jun; Saito, Hiroya

    2013-01-01

    To evaluate the usefulness of a tool that we developed to simulate performance of insertion and retrieval of optional inferior vena cava filters to be additionally used in training of beginners with an animal model. Thirty young doctors who had little or no experience in insertion and/or retrieval of filters were subjects of this study to evaluate the training tool. Eleven trainees practiced both insertion and retrieval of filters first with the animal model then with the blood vessel model while 19 trainees first practiced with the blood vessel model then with the animal model. All trainees successfully inserted the filter. Two of the 11 trainees who used the animal model before the blood vessel model failed in retrieval, and 2 of the 19 trainees who used the blood vessel model before the animal model failed. In the former group, mean time for filter implantation and withdrawal in the animal model was 75 ± 62 s and 341 ± 238 s, respectively, and in the latter group were 54 ± 16 s and 311 ± 236 s, respectively. Training with the combination of a blood vessel model and animal model is helpful for beginners to learn to insert and withdraw optional filters.

  8. Effect of the number of abutments on biomechanics of Branemark prosthesis with straight and tilted distal implants

    Directory of Open Access Journals (Sweden)

    Marcos Michelon Naconecy

    2010-04-01

    Full Text Available OBJECTIVE: This study aimed to evaluate the bending moments, and compressive and tensile forces in implant-supported prostheses with three, four or five abutments. MATERIAL AND METHODS: Ten Pd-Ag frameworks were tested over two master models with: 1 parallel vertical implants, and 2 tilted distal implants. Strain gauges were fixed on the abutments of each master model to measure the deformation when a static load of 50 N was applied on the cantilever (15 mm. The deformation values were measured when the metallic frameworks were tested over three, four or five abutments, and transformed into force and bending moment values. Data were analyzed by ANOVA and Tukey's test for multiple comparisons at 5% level of significance. RESULTS: Abutment #1 (adjacent to the cantilever had the highest values of force and sagittal bending moment for all tests with three, four or five abutments. Independently from the number of abutments, axial force in abutment #1 was higher in the vertical model than in the tilted model. Total moment was higher with three abutments than with four or five abutments. Independently from the inclination of implants, the mean force with four or five abutments was lower than that with three abutments. CONCLUSION: The results suggest that in the set-ups with four or five abutments tilted distal implants reduced axial force and did not increase bending moments.

  9. Effect of the number of abutments on biomechanics of Branemark prosthesis with straight and tilted distal implants.

    Science.gov (United States)

    Naconecy, Marcos Michelon; Geremia, Tomás; Cervieri, André; Teixeira, Eduardo Rolim; Shinkai, Rosemary Sadami

    2010-01-01

    This study aimed to evaluate the bending moments, and compressive and tensile forces in implant-supported prostheses with three, four or five abutments. Ten Pd-Ag frameworks were tested over two master models with: 1) parallel vertical implants, and 2) tilted distal implants. Strain gauges were fixed on the abutments of each master model to measure the deformation when a static load of 50 N was applied on the cantilever (15 mm). The deformation values were measured when the metallic frameworks were tested over three, four or five abutments, and transformed into force and bending moment values. Data were analyzed by ANOVA and Tukey's test for multiple comparisons at 5% level of significance. Abutment #1 (adjacent to the cantilever) had the highest values of force and sagittal bending moment for all tests with three, four or five abutments. Independently from the number of abutments, axial force in abutment #1 was higher in the vertical model than in the tilted model. Total moment was higher with three abutments than with four or five abutments. Independently from the inclination of implants, the mean force with four or five abutments was lower than that with three abutments. The results suggest that in the set-ups with four or five abutments tilted distal implants reduced axial force and did not increase bending moments.

  10. Mathematical Models and Numerical Simulations for the Blood Flow in Large Vessels

    Directory of Open Access Journals (Sweden)

    Titus PETRILA

    2012-12-01

    Full Text Available We are proposing a non-Newtonian, Cross type rheological model for the blood flow, under the conditions of an unsteady flow regime connected with the rhythmic pumping of the blood by the heart. We admit the incompressibility and homogeneity of the blood while its flow is laminar and the exterior body forces are neglected. We take also into account the viscoelastic behavior of the vessel walls. The mathematical equations and the appropriate boundary conditions are considered in cylindrical (axisymmetric coordinates. Numerical experiments in case of stenosed artery and in artery with aneurysm (using COMSOL Multiphysics 3.3 are made. The variation of the wall shear stress, which is believed to have a special importance in the rupture of aneurysms, is calculated using both a Newtonian and a non-Newtonian model.

  11. Apparatus and method for examining a blood vessel of interest using radiation detected outside the body

    International Nuclear Information System (INIS)

    Shaw, R.F.

    1982-01-01

    Stenotic atherosclerotic lesions of the coronary arteries are detected by injecting a number of particulate signal sources such as positron-emitting particles (e.g. gallium 68) into the blood of a subject to determine the velocity of blood flow through the coronary vessels. The particles are tracked in three dimensions whenever they appear in the region of the heart by means of high-resolution high-speed gamma detectors that surround the chest. These recordings of particle position as a function of time are analyzed, and the velocity of blood as it flows through the coronary artery is measured by timing the transit of the particle. From the accumulated data of multiple particle transits through the coronary circulation, a three-dimensional representation of the lumen of the coronary arterial system is constructed

  12. Brain Blood Vessel Map Extraction Using Wavelet-based DSA Fusion

    Directory of Open Access Journals (Sweden)

    Saba Momeni

    2013-10-01

    Full Text Available Recently image fusion has prominent and applicable roles in medical image processing. Digital subtraction angiography (DSA image is applied to display map of blood vessels. In this essay, a new fusion algorithm for DSA serial images based on discrete wavelet transform coefficients is proposed. Fusion of high frequency coefficients is based on proposed fusion map and four evaluation criteria which introduce level of coefficient's energy. Our algorithm will be compared for different wavelet transforms and activity criteria for high frequency coefficients. The comparisons are based on the objective evaluation criteria which show measure of noise existence, sharpness and correlation between the fusion result and reference image. Finally, Meyer discrete wavelet transform is resulted as the best wavelet transform, and sum of modified Laplacian, local energy are introduced as activity level measurment for high and low frequency coefficients in process of brain vessel map extraction.

  13. [Molecular mechanism for the establishment of blood-vessel gateway for immune cells in the CNS.

    Science.gov (United States)

    Murakami, Masaaki

    We have been studying about the molecular mechanism responsible for the establishment of the blood-vessel gateway through which immune cells enter the CNS. We have discovered three kinds of gateways in a multiple sclerosis model, EAE, based on the neural stimulations and named them the gravity-gateway reflex, electric-gateway reflex, and pain-gateway reflex, respectively. All gateway reflexes are involved in specific crosstalk between sensory-sympathetic pathways. For example, in the gravity-gateway reflex, gravity-mediated sensory stimulation via the soleus muscles activates fifth lumber(L5)dorsal loot ganglions to activate L5 sympathetic ganglions, which express norepinephrine at specific vessels of the L5 cord. We explain these three types of gateway reflexes in this chapter.

  14. [Are the cobalt hip prosthesis dangerous?].

    Science.gov (United States)

    Mistretta, Virginie; Kurth, William; Charlier, Corinne

    The placement of a hip prosthesis is one of the most common orthopedic surgical procedures. Some implants contain metal and are therefore capable of releasing metal particles like cobalt in patients who wear metal prostheses. Cobalt can be responsible of local toxicity (including metallosis, hypersensitivity reaction, and benign tumor) or systemic toxicity (including cardiomyopathy, polycythemia, hypothyroidism, and neurological disorders). To monitor potential toxicity of metal hip prostheses, an annual monitoring of patients implanted is recommended and includes clinical examination, radiological examination and blood cobalt determination. The cobalt concentration in blood allows to estimate the risk of toxicity and to evaluate the performance of the implant. The currently recommended threshold value is equal to 7 µg of cobalt per liter of blood. Our study, conducted on 251 patients over a period of 4 years, has shown that the cobalt concentration average was 2.51 µg/l in blood, with 51 patients having a cobaltemia higher than the threshold of 7 µg/l. © 2016 médecine/sciences – Inserm.

  15. Understanding How Space Travel Affects Blood Vessels: Arterial Remodeling and Functional Adaptations Induced by Microgravity

    Science.gov (United States)

    Delp, Michael; Vasques, Marilyn; Aquilina, Rudy (Technical Monitor)

    2002-01-01

    Ever rise quickly from the couch to get something from the kitchen and suddenly feel dizzy? With a low heart rate and relaxed muscles, the cardiovascular system does not immediately provide the resistance necessary to keep enough blood going to your head. Gravity wins, at least for a short time, before your heart and blood vessels can respond to the sudden change in position and correct the situation. Actually, the human cardiovascular system is quite well adapted to the constant gravitational force of the Earth. When standing, vessels in the legs constrict to prevent blood from collecting in the lower extremities. In the space environment, the usual head-to-foot blood pressure and tissue fluid gradients that exist during the upright posture on Earth are removed. The subsequent shift in fluids from the lower to the upper portions of the body triggers adaptations within the cardiovascular system to accommodate the new pressure and fluid gradients. In animal models that simulate microgravity, the vessels in the head become more robust while those in the lower limbs become thin and lax. Similar changes may also occur in humans during spaceflight and while these adaptations are appropriate for a microgravity environment, they can cause problems when the astronauts return to Earth or perhaps another planet. Astronauts often develop orthostatic intolerance which means they become dizzy or faint when standing upright. This dizziness can persist for a number of days making routine activities difficult. In an effort to understand the physiological details of these cardiovascular adaptations, Dr. Michael Delp at Texas A&M University, uses the rat as a model for his studies. For the experiment flown on STS-107, he will test the hypothesis that blood vessels in the rats' hindlimbs become thinner, weaker, and constrict less in response to pressure changes and to chemical signals when exposed to microgravity. In addition, he will test the hypothesis that arteries in the brain

  16. P2X7R antagonism after subfailure overstretch injury of blood vessels reverses vasomotor dysfunction and prevents apoptosis.

    Science.gov (United States)

    Luo, Weifeng; Feldman, Daniel; McCallister, Reid; Brophy, Colleen; Cheung-Flynn, Joyce

    2017-12-01

    Human saphenous vein (HSV) is harvested and prepared prior to implantation as an arterial bypass graft. Injury and the response to injury from surgical harvest and preparation trigger cascades of molecular events and contribute to graft remodeling and intimal hyperplasia. Apoptosis is an early response after implantation that contributes the development of neointimal lesions. Here, we showed that surgical harvest and preparation of HSV leads to vasomotor dysfunction, increased apoptosis and downregulation of the phosphorylation of the anti-apoptotic protein, Niban. A model of subfailure overstretch injury in rat aorta (RA) was used to demonstrate impaired vasomotor function, increased extracellular ATP (eATP) release, and increased apoptosis following pathological vascular injury. The subfailure overstretch injury was associated with activation of p38 MAPK stress pathway and decreases in the phosphorylation of the anti-apoptotic protein Niban. Treatment of RA after overstretch injury with antagonists to purinergic P2X7 receptor (P2X7R) antagonists or P2X7R/pannexin (PanX1) complex, but not PanX1 alone, restored vasomotor function. Inhibitors to P2X7R and PanX1 reduced stretch-induced eATP release. P2X7R/PanX1 antagonism led to decrease in p38 MAPK phosphorylation, restoration of Niban phosphorylation and increases in the phosphorylation of the anti-apoptotic protein Akt in RA and reduced TNFα-stimulated caspase 3/7 activity in cultured rat vascular smooth muscle cells. In conclusion, inhibition of P2X7R after overstretch injury restored vasomotor function and inhibited apoptosis. Treatment with P2X7R/PanX1 complex inhibitors after harvest and preparation injury of blood vessels used for bypass conduits may prevent the subsequent response to injury that lead to apoptosis and represents a novel therapeutic approach to prevent graft failure.

  17. 21 CFR 888.3025 - Passive tendon prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Passive tendon prosthesis. 888.3025 Section 888...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3025 Passive tendon prosthesis. (a) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or a...

  18. 21 CFR 870.3450 - Vascular graft prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular graft prosthesis. 870.3450 Section 870... prosthesis. (a) Identification. A vascular graft prosthesis is an implanted device intended to repair... Prostheses 510(k) Submissions.” [66 FR 18542, Apr. 10, 2001] ...

  19. Mitral valve replacement in infants and children 5 years of age or younger: Evolution in practice and outcome over three decades with a focus on supra-annular prosthesis implantation

    Science.gov (United States)

    Tierney, Elif Seda Selamet; Pigula, Frank A.; Berul, Charles I.; Lock, James E.; del Nido, Pedro J.; McElhinney, Doff B.

    2014-01-01

    Objective Successful mitral valve replacement in young children is limited by the lack of small prosthetic valves. Supra-annular prosthesis implantation can facilitate mitral valve replacement with a larger prosthesis in children with a small annulus, but little is known about its effect on the outcomes of mitral valve replacement in young children. Methods One hundred eighteen children underwent mitral valve replacement at 5 years of age or younger from 1976–2006. Mitral valve replacement was supra-annular in 37 (32%) patients. Results Survival was 74% ± 4% at 1 year and 56% ± 5% at 10 years but improved over time (10-year survival of 83% ± 7% from 1994–2006). Factors associated with worse survival included earlier mitral valve replacement date, age less than 1 year, complete atrioventricular canal, and additional procedures at mitral valve replacement, but not supra-annular mitral valve replacement. As survival improved during our more recent experience, the risks of supra-annular mitral valve replacement became apparent; survival was worse among patients with a supra-annular prosthesis after 1991. A pacemaker was placed in 18 (15%) patients within 1 month of mitral valve replacement and was less likely in patients who had undergone supra-annular mitral valve replacement. Among early survivors, freedom from redo mitral valve replacement was 72% ± 5% at 5 years and 45% ± 7% at 10 years. Twenty-one patients with a supra-annular prosthesis underwent redo mitral valve replacement. The second prosthesis was annular in 15 of these patients and upsized in all but 1, but 5 required pacemaker placement for heart block. Conclusions Supra-annular mitral valve replacement was associated with worse survival than annular mitral valve replacement in our recent experience. Patients with supra-annular mitral valve replacement were less likely to have operative complete heart block but remained at risk when the prosthesis was subsequently replaced. PMID:18954636

  20. Control of weft yarn or density improves biocompatibility of PET small diameter artificial blood vessels.

    Science.gov (United States)

    Hu, Xingyou; Hu, Tao; Guan, Guoping; Yu, Shaoting; Wu, Yufen; Wang, Lu

    2018-04-01

    Polyethylene glycol terephthalate (PET) fabrics with woven structures have proved to be quite effective for use on large diameter artificial blood vessels. However, their use within small-diameter artificial blood vessels has been associated with poor long-term patency, a problem resulting from slow endothelialization on PET and an over hyperplasia of smooth muscle cells. Previous research from our laboratory has revealed that ICAM-1 can be used as a marker to investigate cell adhesion, an effect which was closely associated with cell behavior on the surface of polycaprolactone (PCL) films. Moreover, we found that the coarseness or pore size of the surface exerts considerable influence on cell adhesion and proliferation on PCL films. In this study, we successfully fabricated six types of PET woven fabrics with varying gradients of tightness and porosities. Levels of ICAM-1 expression (membrane ICAM-1 & soluble ICAM-1) were then determined in these woven fabrics. Our results show that increased levels of mICAM-1 and decreased levels of sICAM-1 expression were obtained in HUVECs seeded on these six samples. These findings indicate that cell adhesion and proliferation on fabric surfaces were strongly influenced by their structural parameters, in particular the initial adhesion between the cell and fabric surface. In addition, we also found that extracellular matrix adhesion tends to prefer flat and tight surfaces, which promotes cell-cell and cell-matrix interactions, as well as the endothelialization on the surface of PET fabrics. These findings provide some novel insights with regard to the design and application of small-diameter artificial blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 954-964, 2018. © 2017 Wiley Periodicals, Inc.

  1. A new model for the artificial aorta blood vessels using double-sided radial functionally graded biomaterials.

    Science.gov (United States)

    Salimi Bani, M; Asgharzadeh Shirazi, H; Ayatollahi, M R; Asnafi, Alireza

    2017-05-01

    Based on radial functionally graded biomaterials and inspired by the geometry of a real aorta blood vessel, a new model was proposed to fabricate the artificial blood vessels. A finite element analyzer is employed to reach the optimal and proper material properties while earlier, it was validated by two famous theories, i.e., the first shear deformation and the plane elasticity. First, the geometry of a real ascending aorta part was simulated and then solved under the axially varying blood pressure and other real and actual conditions. Since the construction of artificial blood vessels just similar to the natural one is impossible, it was tried to find the best substitutes for other materials. Due to the significant properties of functionally graded biomaterials in the reduction in sudden changes of stress and deformation, these types of materials were selected and studied. Two types of conventional single-sided and an efficient double-sided radial functionally graded vessel were proposed and simulated. The elastic behaviors of proposed vessels were obtained and compared to ones previously attained from the real vessel. The results show that all the desired behaviors cannot be achieved by using a conventional single-sided radial FG vessel. Instead and as a conjecture, a smart double-sided radial FG biomaterial is suggested. Fortunately, the proposed material can meet all the desired goals and satisfy all of the indices simultaneously.

  2. [Bone-anchored auricular prosthesis].

    Science.gov (United States)

    Bille, M; Homøe, P; Vesterhauge, S; Rixen, M; Bretlau, P

    1994-10-03

    During the period February 1989-September 1991, 15 patients with absent or defective pinna were treated with a bone-anchored auricular prosthesis at the ENT-department, Rigshospitalet, Copenhagen. These patients were followed up from the hospital records and by means of a questionnaire. Altogether 40 titanium implants have been inserted, of which one implant was found not to be integrated at the time of the second-stage surgery. Five patients underwent additional surgery, one patient because of non-integration of a screw, and four patients on account of soft-tissue reactions. From the questionnaire replies it appears that all patients found the cosmetic result and the technique concerning mounting of the prosthesis very satisfactory. Nearly half the patients found that the care of the skin around the abutments caused considerable problems. Three patients had experienced unintended losses of the prosthesis. In conclusion, treatment with a bone anchored auricular prosthesis has considerable advantages compared to treatment with a prosthesis attached by adhesive. Furthermore the use of a bone-anchored prosthesis should be considered a viable alternative to surgical reconstruction because of the outstanding aesthetic result and because the surgical procedure puts less strain on the patient. The disadvantage of the method is the lifelong daily care of the skin and the dependence on the health services.

  3. Design and development of a blood vessel localization system using a Nir viewer

    International Nuclear Information System (INIS)

    Hernandez R, A.; Plascencia C, L. E.; Cordova F, T.; Padilla R, N.

    2017-10-01

    In addition to the multiple applications of ionizing radiation in clinical diagnosis there is the possibility of using another part of the electromagnetic spectrum such as near infrared (Nir). This paper presents the design and construction of a Nir Biosensor in a range between 800 and 900 nm, which allows the visualization of blood vessels for the venepuncture procedure with the aim of reducing the trauma of venous access to patients of all ages. The possibility that the device is used in the location of venous ulcers as an alternative to veno grams obtained by X-rays is also explored. (Author)

  4. Patient-prosthesis mismatch in patients treated with transcatheter aortic valve implantation – predictors, incidence and impact on clinical efficacy. A preliminary study

    Directory of Open Access Journals (Sweden)

    Karol Zbroński

    2017-11-01

    Full Text Available Introduction : Patient-prosthesis mismatch (PPM is relatively frequent after surgical aortic valve replacement (SAVR and negatively impacts prognosis. Aim : We sought to determine the frequency and clinical effects of PPM after transcatheter aortic valve implantation (TAVI. Material and methods : Overall, 238 patients who underwent TAVI were screened. Moderate PPM was defined as indexed effective orifice area (EOAi between 0.65 and 0.85 cm2/m2, and severe PPM as < 0.65 cm2/m2. All-cause mortality and the Valve Academic Research Consortium 2 (VARC-2 defined composite of clinical efficacy at 1 year were the primary endpoints. Results : Finally, 201 patients were included (mean age: 79.6 ±7.4 years, 52% females. The femoral artery served as the delivery route in 79% and most of the prostheses were self-expanding (68%. Any PPM was present in 48 (24% subjects, and only 7 (3.5% had severe PPM. Body surface area (BSA independently predicted any PPM (OR = 16.9, p 20 mm Hg. Conclusions : Severe PPM after TAVI is rare, can be predicted by larger BSA and does not seem to affect mid-term mortality or composite clinical outcome. Larger studies are needed to find different independent predictors of PPM and elucidate its impact in terms of device durability and long-term clinical efficacy.

  5. Effects of a protein glycocalyx in the hemodynamics of small blood vessels

    Science.gov (United States)

    Dimakopoulos, Yiannis; Delidakis, George; Tsamopoulos, John

    2015-11-01

    Glycocalyx is a protein layer of approximate thickness 0.5 μm that lines vessel walls. We study the effects this layer has on the blood flow inside arterioles and venules, where the relative size of the glycocalyx is significant. To properly describe phenomena that naturally occur in blood flow, such as the inhomogeneous distribution of red blood cells and their aggregation, we use an improved viscoelastic constitutive model. The glycocalyx layer is modeled as fixed porous media. Cells cannot penetrate inside it, since its hydraulic permeability is very low, and the flow inside this layer is described by the equations for a viscous fluid with an extra Brinkman term to account for the effects the porous medium has on the flow. The closed set of equations is solved using the Finite Element method, assuming steady-state with dependence only in the r-direction. Our results are favorably compared with the in vivo velocity profiles in venules of mice produced by Damiano et al. (2004) and the formation of cell-free layer near glycocalyx. Flow inside the glycocalyx layer is found to be severely attenuated due to the low hydraulic permeability, which can have interesting implications in the transport of various substances form the blood to the tissues or in the use of shear stresses as signals for the endothelial surface cells. Finally, we simulate the transient blood flow under pulsatile conditions.

  6. Limitations of quantitative photoacoustic measurements of blood oxygenation in small vessels

    International Nuclear Information System (INIS)

    Sivaramakrishnan, Mathangi; Maslov, Konstantin; Zhang, Hao F; Stoica, George; Wang, Lihong V

    2007-01-01

    We investigate the feasibility of obtaining accurate quantitative information, such as local blood oxygenation level (sO 2 ), with a spatial resolution of about 50 μm from spectral photoacoustic (PA) measurements. The optical wavelength dependence of the peak values of the PA signals is utilized to obtain the local blood oxygenation level. In our in vitro experimental models, the PA signal amplitude is found to be linearly proportional to the blood optical absorption coefficient when using ultrasonic transducers with central frequencies high enough such that the ultrasonic wavelengths are shorter than the light penetration depth into the blood vessels. For an optical wavelength in the 578-596 nm region, with a transducer central frequency that is above 25 MHz, the sensitivity and accuracy of sO 2 inversion is shown to be better than 4%. The effect of the transducer focal position on the accuracy of quantifying blood oxygenation is found to be negligible. In vivo oxygenation measurements of rat skin microvasculature yield results consistent with those from in vitro studies, although factors specific to in vivo measurements, such as the spectral dependence of tissue optical attenuation, dramatically affect the accuracy of sO 2 quantification in vivo

  7. A numerical analysis on the curved bileaflet Mechanical Heart Valve (MHV) : leaflet motion and blood flow in an elastic blood vessel