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Sample records for above-knee femoropopliteal bypass

  1. Dacron or PTFE for above-knee femoropopliteal bypass. a multicenter randomised study

    Jensen, L P; Lepäntalo, M; Fossdal, J E; Røder, Ole Christian; Jensen, B S; Madsen, M S; Grenager, O; Fasting, H; Myhre, H O; Baekgaard, N; Nielsen, O M; Helgstrand, U; Schroeder, T V

    2007-01-01

    To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass.......To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass....

  2. Long term results of polytetrafluoroethylene in above knee femoropopliteal bypass for critical ischaemia.

    Kavanagh, E G

    2012-02-03

    Ninety-six consecutive above-knee femoropopliteal bypasses, using polytetrafluoroethylene (PTFE) preferentially, were performed for limb-threatening ischaemia. Cumulative primary graft patency was 68 per cent, 49 per cent and 36 per cent and limb salvage 93 per cent, 85 per cent and 75 per cent at 1, 3 and 5 yr respectively. As a result of poor long term survival (51 per cent at 5 yr), and the healing of remedial lesions before graft occlusion, 68 patients (72 per cent) required no further intervention. Eighteen secondary bypasses were undertaken, 12 using ipsilateral saphenous vein. In this group of elderly patients with poor life expectancy, where a limited operation is desirable, the use of PTFE provided excellent limb salvage with low morbidity. Although we can no longer justify our continued use of PTFE in every case of critical ischaemia because of its inferior patency to autogenous vein, we continue to use it preferentially in patients whose lifespan is likely to be short and in cases where a remedial lesion is present.

  3. Dacron or PTFE for above-knee femoropopliteal bypass

    Jensen, Leif P.; Lepäntalo, M.; Fossdal, J.E.;

    2007-01-01

    analysis. Age, gender, indication (claudication: 65%), run-off (2 or 3 vessels: 76%), diabetes (17%) and hypertension (31%) as well as cerebrovascular (9%) and cardiac (33%) risks were evenly distributed. Patients were followed postoperatively at 1, 12 and 24 months. Patency assessment was based on ankle......-brachial pressures or imaging in case of doubt. RESULTS: The two-year primary patency rates for Dacron and PTFE were 70% and 57% (p=0.02), whereas the secondary patency rates were 76% and 65% (p=0.04), respectively. Primary patency at two years was significantly influenced by the number of patent crural vessels (two...

  4. Percutaneous mechanical thrombectomy for treatment of acute femoropopliteal bypass occlusion

    Lichtenberg M

    2012-05-01

    Full Text Available Michael Lichtenberg1, Matthias Käunicke1, Birgit Hailer1,21Cardiovascular Clinic, Vascular Center, Katholisches Klinikum Essen, Germany; 2University of Witten/Herdecke, GermanyAbstract: Acute and subacute ischemia of the legs in acute and subacute femoropopliteal bypass occlusion is a dramatic situation that endangers the survival of the limbs, depending on the severity of the ischemia. Different therapy options like percutaneous mechanical thrombectomy procedures, which include rotational thrombectomy, have become available in recent years, in addition to local lysis and surgical thrombectomy. Surgical thrombectomy using the Fogarty catheter technique, in particular, shows an increased incidence of perioperative complications but only small technical success rates in randomized trials. On the other hand, local lysis is associated with increased costs due to resource-consuming measures, such as intensive monitoring and repeat angiographies, in addition to bleeding complications. In the past, further development of the Straub Rotarex® system as an endovascular therapy option has demonstrated good success leading to amputation-free survival in multiple studies. At the same time, a low rate of complications with use has been documented. Most examinations have been conducted in the thigh. To date, there are little investigational data on its use in acutely and subacutely occluded femoropopliteal bypasses. In this paper, the current study-based significance of the Rotarex system for this indication is analyzed based on the existing literature and the authors' own experiences with 22 patients.Keywords: acute limb ischemia, femoropopliteal bypass, local lysis, rotational thrombectomy

  5. Continuous crossover femoropopliteal bypass in a 68-year-old gentleman with rest pain.

    Smith, F M

    2012-02-03

    Patients who have had multiple previous attempts at limb salvaging surgery frequently go on to have an amputation. This, however, results both in psychological perturbation for the patient and high rehabilitation costs for the community. Successful limb salvage surgery therefore has an important role in vascular surgery. We describe the management of a patient with critical limb ischemia that had previously undergone multiple limb salvage procedures and whose limb was saved by the use of a continuous femoropopliteal crossover bypass graft. The patient, who may have been deemed by some as a candidate for amputation, has full use of his limb 6 months after surgery with ankle brachial pressure index readings of 0.6. Continuous femoropopliteal crossover bypass grafting is a poorly described surgical technique that may be appropriate in a subgroup of patients and may allow salvage of a limb that otherwise may have been deemed fit for amputation.

  6. Pathophysiology and treatment of edema following femoropopliteal bypass surgery

    te Slaa, A.; Dolmans, D. E. J. G. J.; Ho, G. H.; Moll, F. L.; van der Laan, L.

    2012-01-01

    Substantial lower-limb edema affects the majority of patients who undergo peripheral bypass surgery. Edema has impairing effects on the microvascular and the macrovascular circulation, causes discomfort and might delay the rehabilitation process of the patient. However, the pathophysiology of this e

  7. Discharge Destination after Elective Femoropopliteal Bypass in Patients without Critical Ischemia.

    Kauvar, David S; Osborne, Candice L

    2016-05-01

    Femoropopliteal bypass (FPB) remains a widely accepted treatment option for symptomatic leg ischemia, even in patients without features of critical limb ischemia (CLI). These patients are revascularized to improve symptoms of exertional limb pain and the goal of such treatment is to increase their ability to ambulate within the community. Therefore, the anticipated initial discharge disposition for a patient without CLI undergoing FPB is back to their home. This study examined the disposition at initial discharge of such patients. Data from the 2012 National Surgical Quality Improvement Program registry was queried for all elective FPB performed in patients without CLI. Analysis was limited to patients surviving to initial discharge who were living independently at home before surgery. Initial disposition was defined as to HOME or to a FACILITY (either rehabilitation or skilled nursing); these constituting the study groups. Univariate analysis and multivariable logistic regression were performed to identify patient risk factors for failure to discharge to home. In-hospital and postoperative events were also recorded and compared. Significance was defined at P ≤ 0.05. In National Surgical Quality Improvement Program 2012, 1060 cases of elective FPB in patients without CLI were found. The mean± SD age of the population was 65 ± 9 years; 359 (34%) of patients were female; 198 (19%) had a reported race other than white; and most (893, 84%) had hypertension. 60 (6%) patients failed to discharge to home (26 to rehabilitation, 34 to skilled nursing). On univariate analysis, age (FACILITY 68 ± 11 years vs HOME 65 ± 9 years, P = 0.009), female gender (55% vs 37%, P accident, 5% vs 2.6%, P = 0.01) were found to predict failure to discharge to home. On multivariate analysis, female gender [odds ratio (OR) = 2.4, 95% confidence interval = 1.4-4.1, P = 0.002], and a history of congestive heart failure (OR = 4.7, 1.2-18, 0.03] or cerebrovascular accident (OR = 3.4, 1

  8. Comparison of long-term results of above-the-knee femoro-popliteal bypass with autogenous vein and polytetrafluoroethylene grafts

    Heo, Seon-Hee; Park, Yang-Jin; Woo, Shin-Young; Kim, Dong-Ik; Kim, Young-Wook

    2014-01-01

    Purpose To analyze the long-term results of above-the-knee femoro-popliteal bypass (ATKFPB) with vein grafts compared with polytetrafluoroethylene (PTFE) grafts. Methods A database of patients with chronic atherosclerotic occlusive disease who underwent ATKFPB was retrospectively reviewed. Characteristics of patient and arterial lesion, and follow-up results were compared between vein grafts and PTFE grafts. Graft patency was determined by periodic examinations of duplex ultrasonography or CT...

  9. Sciatic Neuroma Presenting Forty Years After Above-Knee Amputation

    Kitcat, M; Hunter, J. E.; C.M. Malata

    2009-01-01

    We report a case of a sciatic neuroma presenting forty years after above knee amputation. Patients developing neuroma following a limb amputation can present with stump pain which is commonly resistant to medical intervention. The length of interval from the initial injury to presentation is widely variable. Diagnosis relies on clinical suspicion and accurate assessment, radiological imaging and, if indicated, surgical exploration. MRI provides a better soft tissue definition than CT and is m...

  10. Optimal control for the active above-knee prosthesis.

    Popović, D; Oğuztöreli, M N; Stein, R B

    1991-01-01

    Control of an active above-knee prosthesis has been simulated for a selected gait activity using a hierarchical closed-loop method. An extension of finite-state control, referred to as artificial reflex control, was adopted at the strategic level of control. At the actuator level of control an optimal tracking method, based on dynamic programming, is applied. This deals mainly with the actuator level of control, but considers the interaction of the leg dynamics and the switching effects of artificial reflex control. Optimal tracking at the actuator level of the above-knee prosthesis reduces the on-off effects of finite-state methods, such as artificial reflex control. The proposed method can also be used for the design of prosthetic elements. Specific attention is paid to the limited torque and power in the prosthetic joint actuator, which are imposed by the principle of self-containment in the artificial leg. The hierarchical structure, integrating artificial reflex control and optimal tracking, can be used in real time, as estimated from the number of computer operations required for the suggested method. PMID:2048773

  11. Ischaemic wound complications in above-knee amputations in relation to the skin perfusion pressure

    Holstein, P

    1980-01-01

    Healing of the stumps in 59 above-knee amputations was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 131I-(-) or 125I-(-) antipyrine mixed with histamine. Out of the 11 cases with an SPP below 30 mm...... ischaemic wound complications in above-knee amputations as has previously been shown to be the case in below-knee amputations....

  12. Five-year outcomes following a randomized trial of femorofemoral and femoropopliteal bypass grafting with heparin-bonded or standard polytetrafluoroethylene grafts

    Lindholt, J S; Houlind, K; Gottschalksen, B;

    2016-01-01

    BACKGROUND: Cohort studies suggest superior long-term patency of luminal heparin-bonded polytetrafluoroethylene (Hb-PTFE) bypass grafts compared with standard PTFE grafts. The aim of this study was to compare the outcomes of Hb-PTFE grafts with those of standard PTFE grafts 5 years after a random...... likely to have a patent graft at 5 years than those with standard PTFE grafts....

  13. Bipolar hip hemiarthroplasty in a patient with an above knee amputation: a case report

    Liebergall Meir

    2009-07-01

    Full Text Available Abstract The treatment of an above knee amputee who has sustained a fracture of femoral neck is a challenge for both the orthopaedic surgeon and the rehabilitation team. We present a case of such a patient and discuss different difficulties in his treatment.

  14. Bipolar hip hemiarthroplasty in a patient with an above knee amputation: a case report

    Liebergall Meir; Schwartz Isabella; Safran Ori; Hernandez Miguel; Kandel Leonid; Mattan Yoav

    2009-01-01

    Abstract The treatment of an above knee amputee who has sustained a fracture of femoral neck is a challenge for both the orthopaedic surgeon and the rehabilitation team. We present a case of such a patient and discuss different difficulties in his treatment.

  15. Total hip arthroplasty in a patient with arthrogryphosis and an ipsilateral above knee amputation.

    Leonard, Michael

    2010-10-01

    The authors present the case of a young man with arthrogryphosis multiplex congenita and an above knee amputation who underwent an ipsilateral total hip replacement. The unique aspects of the case and technical difficulties are highlighted. Follow-up at five years revealed an excellent clinical and radiological outcome.

  16. Wound healing in above-knee amputations in relation to skin perfusion pressure

    Holstein, P; Dovey, H; Lassen, N A

    1979-01-01

    In 59 above-knee amputations healing of the stumps was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 1318-- or 125I--antipyrine mixed with histamine. Out of the 11 cases with an SPP below 30 mmHg no...

  17. Assessment of AK (Above Knee) Prosthesis with Different Ankle Assembly Using GRF Pattern in Stance Phase

    Kim, Sung-Min; Kim, Sung-Jae; Bae, Ha-Suk

    In this study, ground reaction force (GRF), absolute symmetry index (ASI) and coefficient of variation (CV) of fixed, single-axis and multi-axis prosthetic ankle assemblies were investigated by biomechanical evaluation of above knee amputees. In the experiments, 37 normal male volunteers, two male and two female Above Knee (AK) amputees GRF data were tested with fixed, single-axis and multi-axis prosthetic ankle assembly. A gait analysis was carried out to derive the ratio of GRF to weight as the percentage of total stance phase for ten points. The results showed that fixed-axis ankle assembly was superior to other two ankle assemblies for forwarding and braking forces. Multi-axis ankle was relatively superior to other two ankle assemblies for gait balancing and movement of the mass center. Single-axis ankle was relatively superior to the other two ankle assemblies for CV and ASI of GRF.

  18. A bio-inspired test system for bionic above-knee prosthetic knees

    Wang, Dai-Hua; Xu, Lei; Fu, Qiang; Yuan, Gang

    2013-04-01

    Recently, prosthetic knees in the developing stage are usually tested by installing them on amputees' stumps directly or on above-knee prostheses (AKPs) test platforms. Although amputees can fully provide the actual motion state of the thigh, immature prosthetic knees may hurt amputees. For AKPs test platforms, it just can partly simulate the actual motion state of the thigh with limitation of the motion curve of the thigh, the merits or demerits of newly developed bionic above-knee prosthetic knees cannot be accessed thoroughly. Aiming at the defects of two testing methods, this paper presents a bio-inspired AKPs test system for bionic above-knee prosthetic knees. The proposed bio-inspired AKPs test system is composed of a AKPs test platform, a control system, and a bio-inspired system. The AKPs test platform generates the motion of the thigh simulation mechanism (TSM) via two screw pairs with servo motors. The bio-inspired system includes the tester and the bio-inspired sensor wore by the tester. The control system, which is inspired by the bio-inspired system, generates the control command signal to move the TSM of the AKPs test platform. The bio-inspired AKPs test system is developed and experimentally tested with a commercially available prosthetic knee. The research results show that the bio-inspired AKPs test system can not only ensure the safety of the testers, but also track all kinds of the actual motion state of the thigh of the testers in real time.

  19. Investigation of sit-to-stand and stand-to-sit in an above knee amputee

    Gao, Fan; Zhang, Fan; Huang, He

    2011-01-01

    the objective of this pilot study is twofold: 1) to extract key factors/features in sit-to-stand and stand-to-sit (STS) performed by an above knee (AK) amputee; 2) to propose a convenient way to quantify symmetry. One male unilateral transfemoral amputee participated in the pilot study. The subject was instructed to rise in a comfortable and natural manner and conduct a series of sit-to-stand, stand-to-sit. We simultaneously measured kinematics, kinetics and muscle activities. Principal compo...

  20. Management of neglected femoral neck fracture in above knee amputated limb: A case report

    Umesh Meena; Ramesh Meena; Balaji S; Sahil Gaba

    2015-01-01

    The treatment of an above knee amputee who has sustained a fracture of the femoral neck is a challenging situation for both the orthopedic surgeon and the rehabilitation team.These fractures may be managed acutely either by reduction and internal fixation or by endoprosthetic replacement based on the same criteria as in any other patient with otherwise intact limbs.We present a neglected case treated successfully with valgus osteotomy.We conclude that these fractures should be treated with the same urgency and expertise as similar fractures in non-amputees as long-term survival and good quality of life can be expected.

  1. Management of neglected femoral neck fracture in above knee amputated limb: A case report.

    Meena, Umesh; Meena, Ramesh; S, Balaji; Gaba, Sahil

    2015-01-01

    The treatment of an above knee amputee who has sustained a fracture of the femoral neck is a chal- lenging situation for both the orthopedic surgeon and the rehabilitation team. These fractures may be managed acutely either by reduction and internal fixation or by endoprosthetic replacement based on the same criteria as in any other patient with otherwise intact limbs.We present a neglected case treated successfully with valgus osteotomy. We conclude that these fractures should be treated with the same urgency and expertise as similar fractures in non-amputees as long-term survival and good quality of life can be expected. PMID:26917032

  2. Wound healing in above-knee amputations in relation to skin perfusion pressure

    In 59 above-knee amputations healing of the stumps was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 132I--or 125I--antipyrine mixed with histamine. Out of the 11 cases with an SPP below 30 mmHg no less than nine (82 per cent) suffered severe wound complications. Out of the 48 cases with an SPP above 30 mmHg severe wound complications occurred in only four cases (8 per cent). The difference in wound complication rate is highly significant (P<0.01). The postoperative SPP measured on the stumps was on average only slightly and insignificantly higher than the preoperative values, explaining why the preoperative values related so closely to the postoperative clinical course. We conclude that the SPP can be used to predict ischaemic wound complications in above-knee amputations as has previously been shown to be the case in below-knee amputations. (author)

  3. A prosthetic knee using magnetorhelogical fluid damper for above-knee amputees

    Park, Jinhyuk; Choi, Seung-Bok

    2015-04-01

    A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.

  4. Oclusão arterial aguda de stent fêmoro-poplíteo Acute femoropopliteal artery stent obstruction

    Fabio Henrique Rossi

    2009-09-01

    Full Text Available A oclusão aguda de stent fêmoro-poplíteo pode ser causa de isquemia crítica dos membros inferiores. A terapia fibrinolítica pode não ser a forma de tratamento mais indicada para o grupo de pacientes com esse quadro clínico. Neste artigo, apresentamos um caso em que a retirada de um fragmento de stent por endarterectomia tornou possível a revascularização do membro.Femoropopliteal stent obstruction may be responsible for acute lower limb ischemia. Fibrinolytic treatment may not be the best therapeutic approach in this group of patients. We report a clinical case in which stent fragmentation and endarterectomy enabled femoropopliteal below knee bypass and limb revascularization.

  5. Design and control of a prosthetic leg for above-knee amputees operated in semi-active and active modes

    Park, Jinhyuk; Yoon, Gun-Ha; Kang, Je-Won; Choi, Seung-Bok

    2016-08-01

    This paper proposes a new prosthesis operated in two different modes; the semi-active and active modes. The semi-active mode is achieved from a flow mode magneto-rheological (MR) damper, while the active mode is obtained from an electronically commutated (EC) motor. The knee joint part of the above knee prosthesis is equipped with the MR damper and EC motor. The MR damper generates reaction force by controlling the field-dependent yield stress of the MR fluid, while the EC motor actively controls the knee joint angle during gait cycle. In this work, the MR damper is designed as a two-end type flow mode mechanism without air chamber for compact size. On other hand, in order to predict desired knee joint angle to be controlled by EC motor, a polynomial prediction function using a statistical method is used. A nonlinear proportional-derivative controller integrated with the computed torque method is then designed and applied to both MR damper and EC motor to control the knee joint angle. It is demonstrated that the desired knee joint angle is well achieved in different walking velocities on the ground ground.

  6. Femoropopliteal atherectomy with the Simpson catheter

    Percutaneous atherectomy was performed in 32 patients with 38 symptomatic femoropopliteal stenoses. Treatment was successful in 30 patients, in whom claudication disappeared and the ankle-arm index increased (mean increase, 0.35). Two early thromboses occurred. Angiographic analysis revealed residual stenosis <30% in 30 lesions, no dissecton or embolization, effective treatment of eccentric and calcified lesions, and no significant dissection after additional angioplasty. At 1-year follow-up (19 patients, 21 lesions), there were stable improvement in 13 patients, four restenoses, and two new diseases. The authors conclude that atherectomy restores a large lumen with minimal wall trauma, thus perhaps decreasing the restenosis rate

  7. Bilateral giant femoropopliteal artery aneurysms: a case report

    Perdikides Theodossios P

    2008-04-01

    Full Text Available Abstract Introduction Popliteal artery aneurysms are the most common peripheral arterial aneurysms, and are frequently bilateral. Acute limb ischemia, rupture and compression phenomena can complicate these aneurysms when the diameter exceeds 2 cm. Case Presentation We report an 82-year-old male patient with two giant femoropopliteal aneurysms, 10.5 and 8.5 cm diameters, managed in our institution. Both aneurysms were resected and a polytetrafluoroethylene (PTFE femoropopliteal interposition graft was placed successfully. Management and literature review are discussed. Conclusion We believe this is the first report in the medical literature of bilateral giant femoropopliteal aneurysms.

  8. Early rethrombosis in femoropopliteal occlusions treated with percutaneous transluminal angioplasty

    Jørgensen, B; Meisner, S; Holstein, P;

    1990-01-01

    was explained by a high incidence (41%) of rethrombosis within hours of dilatation. Early rethrombosis was seen with all lengths of occlusion (1-27 cm) with no statistically significant difference from other subsets. This study concludes that conventional PTA in femoropopliteal occlusions should be...... reserved for cases of limb salvage, preferably in patients who are technically inoperable. We suggest a new technique of segmentally enclosed thrombolysis to prevent early rethrombosis after PTA in femoropopliteal occlusions....

  9. Comparison of efficacy in crossing femoropopliteal artery occlusions with movable core and hydrophilic guidewires

    Tønnesen, K H; Bülow, J; Holstein, P;

    1994-01-01

    Compare the recanalization rate of femoropopliteal occlusions between movable core wire guide (MG) and hydrophilic guidewire (HG).......Compare the recanalization rate of femoropopliteal occlusions between movable core wire guide (MG) and hydrophilic guidewire (HG)....

  10. Clinical and haemodynamic evolution of lesions treated by means of atherectomy with SilverHawk in the femoropopliteal sector

    Ibanez, Maria Antonia, E-mail: marianim5@yahoo.es [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain); Cenizo, Noelia, E-mail: noecen@yahoo.es [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain); Rio, Lourdes, E-mail: mlriosol@yahoo.es [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain); Sanchez, Ana, E-mail: assantiago@yahoo.es [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain); San Norberto, Enrique, E-mail: esannorberto@hotmail.com [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain); Brizuela, Jose-Antonio, E-mail: brizsanz@yahoo.es [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain); Gutierrez, Vicente, E-mail: vgutierrezalonso@gmail.com [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain); Vaquero, Carlos, E-mail: cvaquero@med.uva.es [Department of Angiology and Vascular Surgery, Valladolid University Hospital, Valladolid, C/Ramon y Cajal no 3, 47005 Valladolid (Spain)

    2011-11-15

    The objective of the work is to study the clinical and haemodynamic evolution, over 1 year, in patients with femoropopliteal arterial pathology treated by means of atherectomy with the SilverHawk device. Materials and methods: Nineteen (19) patients were treated between December 2008 and May 2009, collecting data on sex, age, comorbidity and clinical degree, with prospective monitoring over 12 months of clinical symptoms, physical examination and ecodoppler, obtaining results on diameter and peak systolic velocity at different arterial levels. Results: Of the 19 patients, 14 were men and 5 women, with a mean age of 70 years, hypertensive (73%), diabetic (63%) and smokers (63%). Six (6) presented disabling claudication and 13 critical ischemia with advanced distal trophic lesions in 5. A good arteriographic result was obtained in 12 cases, a stent was placed on the superficial femoral artery in 5 due to suboptimal outcome. Contrast extravasation was observed in 2, with femoropopliteal bypass performed and one exclusion with endoprosthesis for repair. In the ecodoppler after 1, 3, 6 and 12 months, a progressive reduction in lumen diameter and peak intraarterial systolic velocity was observed, particularly on the distal superficial femoral artery. After one year, 7 patients (36.8%) were symptom-free, 5 (26.3%) presented mild or moderate intermittent claudication and 1 patient (5.3%) presented localised distal trophic lesion. Four (4) major amputations were performed, in 2 the knee was preserved, there were 3 thromboses due to the procedure, a secondary endovascular procedure was performed in one case and a femoropopliteal bypass in another, and there were 2 non procedure-related deaths. Discussion: atherectomy with SilverHawk achieves an improvement in clinical degree, with a good rate of extremity salvage in patients with critical ischemia. In the first year, the ecodoppler shows evolution of the arteriopathy, without this necessarily meaning a clinical worsening.

  11. A Simple Technique for the Positioning of a Patient with an above Knee Amputation for an Ipsilateral Extracapsular Hip Fracture Fixation

    N. Davarinos

    2013-01-01

    Full Text Available The positioning of the patient on the fracture table is critical to the successful reduction and operative fixation of hip fractures which are fixed using the dynamic hip screw system (DHS. There is a standard setup which is commonly used with relative ease. Yet the positioning of patients with amputations either above or below knee of the affected side can pose a significant challenge. We describe a novel positioning technique used on a 51-year old patient with a right above knee amputation who sustained an intertrochanteric extracapsular hip fracture.

  12. Segmentally enclosed thrombolysis in percutaneous transluminal angioplasty for femoropopliteal occlusions

    Jørgensen, B; Tønnesen, K H; Nielsen, J D; Holstein, P; Bülow, J; Jørgensen, M; Andersen, E

    1991-01-01

    Segmentally enclosed thrombolysis (SET) was performed immediately following 34 percutaneous transluminal angioplasties (PTAs) for femoropopliteal occlusions. The dilated segment was sealed off with a double balloon catheter, and recombinant tissue plasminogen activator (rt-PA) 1 mg/ml and heparin...... clinically relevant changes in plasma fibrinogen occurred. Two puncture site hemorrhages did not coincide with the coagulopathy induced by SET. One-year patency was 80%. Early rethrombosis occurred in 9% versus 41% in our previous series on standard PTA for femoropopliteal occlusions (p less than 0...

  13. A review of 155 extra-anatomic bypass grafts.

    Foster, M.C.; Mikulin, T; Hopkinson, B R; Makin, G. S.

    1986-01-01

    Extra-anatomic bypass grafting has been used as treatment for patients with aorto-iliac disease who were considered unfit for aortic surgery. Eighty five percent of the patients had ischaemic pain at rest or skin necrosis. One hundred and three femorofemoral (FF) grafts, 40 axillounifemoral and 12 axillobifemoral grafts were performed. Femoropopliteal extension grafts were performed in 39 cases. The three year cumulative graft patency rate was 69% for FF grafts and 48% for both types of axill...

  14. Axillobifemoral bypass grafting

    Davidović Lazar B.

    2004-01-01

    Full Text Available INTRODUCTION Axillo-femoral bypass (AxF means connecting the axillar and femoral artery with the graft that is placed subcutaneously [1]. Usually, this graft is connected with contralateral femoral artery via one accessory subcutaneous graft, and this connection is known as axillobifemoral bypass (AxFF. This extra-anatomic procedure is an alternative method to the standard reconstruction of aortoiliac region when there are contraindications for general or local reasons. OBJECTIVE The objective of this paper is to show early and late results of AxFF bypass grafting as well as to show the indications for AxFF bypass. METHODS The sample consisted of 37 patients. The procedure was performed in 28 patients who suffered from aortoiliac occlusive disease and who were at high risk due to the comorbidity- in one patient with the rupture of juxtarenal aneurysm of abdominal aorta; in five patients with aortoenteric fistula, in two patients with iatrogenic lesion of abdominal aorta and in one female patient with anus preternaturalis definitivus who was treated for rectovaginal fistula. Donor's right axillary artery was used in 26 cases (70.3%, and donor's left axillary artery was used in 9 cases (29.7%. Dacron graft was used in 34 patients and Polytetrafluo-roethlylene graft was used in three patients. Simultaneously, profundo-plastic was done in four patients and femoro-popliteal bypass was performed in three patients. In five patients who suffered from aortoenteric fistula, simultaneous intervention of gastrointerstinal system has been done, x2 test was used for statistical evaluation and life table method was used for verification of late graft patency. RESULTS The rate of early postoperative mortality was 13.5%. The causes of death were: sepsis -1, MOFS - 3, and infarct myocardium -1. The mean follow up period was 40.1 months, ranging from six months to 17 years. During the follow up period, an early graft thrombosis was identified in two and late graft

  15. Open Surgical Bypass for Superficial Femoral Artery Occlusion Caused by Blunt Trauma

    Ikeda, Akihiko; Kudo, Yohei; Maeda, Michihiro; Tochiki, Aito; Ichimura, Haruto; Uesugi, Masafumi; Jikuya, Tomoaki

    2015-01-01

    Blunt vascular trauma of the lower extremities brings about a high amputation rate, because other organ injuries disturb revascularization. We experienced a case of a superficial femoral artery occlusion caused by blunt trauma. The patient also had a femoral bone fracture and a large skin defect with deep muscular injuries of the thigh. We performed a femoropopliteal (FP) bypass using a saphenous vein which was routed through the contaminated wound. Postoperative vacuum-assisted closure thera...

  16. Early Results with the Use of Heparin-bonded Stent Graft to Rescue Failed Angioplasty of Chronic Femoropopliteal Occlusive Lesions: TASC D Lesions Have a Poor Outcome

    Kuhan, Ganesh, E-mail: gkuhan@nhs.net; Abisi, Said; Braithwaite, Bruce D.; MacSweeney, Shane T. R. [Nottingham University Hospitals, Vascular and Endovascular Unit, Queens Medical Centre (United Kingdom); Whitaker, Simon C.; Habib, Said B. [Nottingham University Hospitals, Department of Radiology, Queen' s Medical Centre (United Kingdom)

    2012-10-15

    Purpose: To evaluate early patency rate of the heparin-bonded stent grafts in atherosclerotic long femoropopliteal occlusive disease, and to identify factors that affect outcome. Methods: Heparin-bonded Viabahn stent grafts were placed in 33 limbs in 33 patients during 2009-2010. The stents were deployed to rescue failed conventional balloon angioplasty. Mean age was 69 (range 44-88) years, and 67 % (22 of 33) were men. Most procedures (21 of 33, 64 %) were performed for critical limb ischemia (33 % for rest pain, 30 % tissue loss). Kaplan-Meier plots and Cox regression analysis were used to identify significant risk factors. Results: The average length of lesions treated was 25 {+-} 10 cm, and they were predominantly TASC (Transatlantic Intersociety Consensus) D (n = 13) and C (n = 17) lesions. The median primary patency was 5.0 months (95 % confidence interval 1.22-8.77). The mean secondary patency was 8.6 months (95 % confidence interval 6.82-10.42). Subsequently, 4 patients underwent bypass surgery and 5 patients underwent major amputation. One patient died. There were 5 in-stent or edge-stent stenoses. Cox multivariate regression analysis identified TASC D lesions to be a significant risk factor for early occlusion (p = 0.035). Conclusion: TASC D lesions of femoropopliteal occlusions have poor patency rates with the use of heparin-bonded stent grafts after failed conventional angioplasty. Alternative options should be considered for these patients.

  17. Outflow distribution at the distal anastomosis of infrainguinal bypass grafts.

    Fisher, R K; How, T V; Bakran, A; Brennan, J A; Harris, P L

    2004-03-01

    Outflow distribution at the distal anastomosis of infrainguinal bypass grafts remains unquantified in vivo, but is likely to influence flow patterns and haemodynamics, thereby impacting upon graft patency. This study measured the ratio of distal to proximal outflow in 30 patients undergoing infrainguinal bypass for lower limb ischaemia, using a flow probe and a transit-time ultrasonic flow meter. The mean outflow distribution was approximately 75% distal to 25% proximal, with above knee anastomoses having a greater proportion of distal flow (84%) compared to below knee grafts (73%). These in vivo flow characteristics differ significantly from those used in theoretical models studying flow phenomena (50:50 and/or 100:0), and should be incorporated into future research. PMID:14757463

  18. Surgical treatment of 82 patients with diabetic lower limb ischemia by distal arterial bypass

    GU Yong-quan; WANG Zhong-gao; ZHANG Jian; QI Li-xing; YU Heng-xi; LI Jian-xin; LI Xue-feng; GUO Lian-rui; LUO Tao; CUI Shi-jun

    2007-01-01

    Background Diabetic lower limb ischemia is a serious complication of diabetes mellitus.This study was conducted to investigate the effectiveness of distal arterial bypass treatment in diabetic patients with lower limb ischemia. Methods From July 2000 to July 2004, 96 lower limbs of 82 diabetic patients (type 2) with severe lower limb ischemia were treated in Xuan Wu Hospital. Arterial bypass with femoro-popliteal polytetrafluoroethylene (PTFE) and graft-tibial autologous grafts was performed on 311 limbs (32.3%). Popliteal-tibial artery bypass alone was performed on 22 limbs (22.9%). Combined iliac artery stenting, femoro-popliteal artery PTFE graft bypass, and graft-tibial artery autologous graft bypass was performed on 12 limbs (12.5%), and femoro-tibial artery graft bypass was performed on 10 limbs (10.4%). Popliteal-tibial-pedal artery graft bypass was performed on 7 limbs (7.3%). Results Arterial grafts in 92 limbs of 79 patients were patent on discharge. Three patients with 4 ischemic limbs (3.7%)died of respiratory failure 12 hours, 3 days and 7 days after operation respectively. Early operation success rate was 96.3% (79/82). Graft patency rate of patients on discharge was 95.8% (92/96). The short-term total effectiveness rate was 83.3% (80/96). Foot ulcer healing rate was 35.7% (10/28). 97.4% (75/77) patients were followed up for a mean of 13.5 months. The long-term total effective rate was 80.7% (71/88). The total amputation rate was 4.5% (4/88). Mortality was 4.5%. The total graft patency rate was 90.9% (80/88).Conclusion In the treatment of diabetic foot, distal lower limb arterial bypass can help to avoid amputation or lower the amputation level, and may promote foot ulcer healing and improve patient's quality of life.

  19. Recanalization of Acute and Subacute Venous and Synthetic Bypass-Graft Occlusions With a Mechanical Rotational Catheter

    PurposePercutaneous mechanical thrombectomy (PMT) is now established as an alternative treatment of acute arterial occlusions in addition to fibrinolysis and surgical thrombectomy. The objective of this retrospective study was the investigation of a rotational atherothrombectomy catheter in terms of safety and efficacy in the treatment of acute and subacute femoropopliteal bypass occlusions.Materials and MethodsForty-two patients (average age 65.8 ± 9.1 years) with acute (<14 days [n = 31]) and subacute (14–42 days [n = 11]) femoropopliteal bypass occlusions were treated consecutively with a rotational debulking and removal catheter (Straub Rotarex). The average occlusion length was 28.4 ± 2.9 (24–34) cm. Thirty-four (81 %) patients underwent venous bypass, and 8 (19 %) patients underwent polytetrafluoroethylene bypass.ResultsThe technical success rate was 97.6 % (41 of 42). In 1 patient, blood flow could not be restored despite the use of the atherothrombectomy system. The average catheter intervention time was 6.9 ± 2.1 (4–9) min. Ankle-brachial index increased from 0.39 ± 0.13 to 0.83 ± 0.11 at discharge and to 0.82 ± 0.17 after 1 month (p < 0.05). There were a total of 2 (4.8 %) peri-interventional complications: One patient developed a distal embolism, which was successfully treated with local lysis, and another patient had a small perforation at the distal anastomosis, which was successfully treated with a stent.ConclusionPMT with the Rotarex atherothrombectomy catheter represents a safe and effective option in the treatment of acute and subacute femoropopliteal bypass occlusions because it can quickly restore blood flow

  20. Recanalization of Acute and Subacute Venous and Synthetic Bypass-Graft Occlusions With a Mechanical Rotational Catheter

    Wissgott, Christian, E-mail: cwissgott@wkk-hei.de; Kamusella, Peter; Andresen, Reimer [Westkuestenklinikum Heide-Academic Teaching Hospital of the Universities of Kiel, Luebeck and Hamburg, Institute of Diagnostic and Interventional Radiology/Neuroradiology (Germany)

    2013-08-01

    PurposePercutaneous mechanical thrombectomy (PMT) is now established as an alternative treatment of acute arterial occlusions in addition to fibrinolysis and surgical thrombectomy. The objective of this retrospective study was the investigation of a rotational atherothrombectomy catheter in terms of safety and efficacy in the treatment of acute and subacute femoropopliteal bypass occlusions.Materials and MethodsForty-two patients (average age 65.8 {+-} 9.1 years) with acute (<14 days [n = 31]) and subacute (14-42 days [n = 11]) femoropopliteal bypass occlusions were treated consecutively with a rotational debulking and removal catheter (Straub Rotarex). The average occlusion length was 28.4 {+-} 2.9 (24-34) cm. Thirty-four (81 %) patients underwent venous bypass, and 8 (19 %) patients underwent polytetrafluoroethylene bypass.ResultsThe technical success rate was 97.6 % (41 of 42). In 1 patient, blood flow could not be restored despite the use of the atherothrombectomy system. The average catheter intervention time was 6.9 {+-} 2.1 (4-9) min. Ankle-brachial index increased from 0.39 {+-} 0.13 to 0.83 {+-} 0.11 at discharge and to 0.82 {+-} 0.17 after 1 month (p < 0.05). There were a total of 2 (4.8 %) peri-interventional complications: One patient developed a distal embolism, which was successfully treated with local lysis, and another patient had a small perforation at the distal anastomosis, which was successfully treated with a stent.ConclusionPMT with the Rotarex atherothrombectomy catheter represents a safe and effective option in the treatment of acute and subacute femoropopliteal bypass occlusions because it can quickly restore blood flow.

  1. Late hemodynamic failure following percutaneous transluminal angioplasty for long and multifocal femoropopliteal stenoses

    Jørgensen, B; Tønnesen, K H; Holstein, P

    1991-01-01

    The outcome of percutaneous transluminal angioplasty (PTA) was evaluated for treatment of 87 limbs with femoropopliteal stenoses, including 55 short stenoses (2.4 +/- 1.6 cm, mean +/- SD), seven single long stenoses (10.4 +/- 2.0 cm), and 25 multifocal stenoses (2.1 +/- 1.6 cm), where two to four...

  2. Bypass materials in vascular surgery

    Willich, Stephan N.

    2006-03-01

    Full Text Available Introduction: Arteriosclerotic changes can lead to circulatory disturbances in various areas of the human vascular system. In addition to pharmacological therapy and the management of risk factors (e. g. hypertension, diabetes, lipid metabolism disorders, and lifestyle, surgical interventions also play an important role in the treatment of arteriosclerosis. Long-segment arterial occlusions, in particular, can be treated successfully with bypass sur-gery. A number of different materials are available for this type of operation, such as autologous vein or pros-thetic grafts comprised of polytetrafluoroethylene (PTFE or Dacron®. Prosthetic materials are used especially in the treatment of peripheral artery disease, such as in aortoiliac or femoropopliteal bypass surgery. The present report will thus focus on this area in order to examine the effectiveness of different bypass materials. Among the efforts being made to refine the newly introduced DRG system in Germany, analysing the different bypass materials used in vascular surgery is particularly important. Indeed, in its current version the German DRG system does not distinguish between bypass materials in terms of reimbursement rates. Differences in cost structures are thus of especial interest to hospitals in their budget calculations, whereas both private and statutory health insurance funds are primarily interested in long-term results and their costs. Objectives: The goal of this HTA is to compare the different bypass materials used in vascular surgery in terms of their medical efficiency and cost-effectiveness, as well as with regard to their ethical, social and legal implications. In addition, this report aims to point out the areas in which further medical, epidemiological and health economic research is still needed. Methods: Relevant publications were identified by means of a structured search of databases accessed through the German Institute of Medical Documentation and Information

  3. Combined treatment of subacute and acute synthetic and venous bypass-graft occlusions with percutaneous mechanical thrombectomy and thrombolysis

    Introduction: Percutaneous mechanical thrombectomy (PMT) is a third choice of treatment for acute arterial occlusions, in addition to thrombolysis and surgical thrombectomy. The aim of this retrospective study was to compare the combined treatment of PMT and local thrombolysis with thrombolysis therapy alone. Materials and methods: Sixty-nine patients with acute (<14 days [n = 35]) or subacute (14–42 days [n = 34]) femoropopliteal bypass occlusions were treated with PMT combined with thrombolysis. Seventy-two patients with acute [n = 40] or subacute [n = 32] femoropopliteal bypass occlusions were treated with thrombolysis alone. The thrombolysis in myocardial infarction (TIMI) classification was used to assess the bypass occlusion. Local thrombolysis time and dosage, reopening time, time in the intensive care unit, necessary surgical re-interventions, and clinical outcome were compared between the 2 groups. Results: The TIMI scores were significantly higher in the PMT plus thrombolysis group than in the thrombolysis group (acute occlusions 1188 versus 935, p < 0.001; subacute occlusions 935 versus 605, p < 0.001). The total urokinase dosage, the total hours of thrombolysis, time in the intensive care unit, and total hospital stay in the acute PMT plus thrombolysis group were significantly lesser than those in the thrombolysis group. After 24 h of treatment, the ankle-brachial index improved in all groups (p < 0.001): in the acute and subacute PMT plus thrombolysis group to 0.63 ± 0.14 and 0.43 ± 0.08, respectively; and in the acute and subacute thrombolysis group to 0.51 ± 0.11 and 0.41 ± 0.04, respectively. Conclusions: PMT combined with thrombolysis is a safe and very effective therapy for acute and subacute femoropopliteal bypass occlusions compared to treatment with thrombolysis alone

  4. Combined treatment of subacute and acute synthetic and venous bypass-graft occlusions with percutaneous mechanical thrombectomy and thrombolysis

    Hundt, Walter, E-mail: hundt@med.uni-marburg.de [Department of Radiology, Philipps University Marburg (Germany); Kalinowski, Mark; Stamm, Anna C. [Department of Radiology, Philipps University Marburg (Germany); Portig, Irene [Department of Cardiology, Division of Angiology, Philipps University Marburg (Germany); Swaid, Zaher; Dietz, Carsten; Geks, Josef [Department of Surgery, Philipps University Marburg (Germany); Burbelko, Mykhaylo [Department of Radiology, Philipps University Marburg (Germany)

    2013-12-01

    Introduction: Percutaneous mechanical thrombectomy (PMT) is a third choice of treatment for acute arterial occlusions, in addition to thrombolysis and surgical thrombectomy. The aim of this retrospective study was to compare the combined treatment of PMT and local thrombolysis with thrombolysis therapy alone. Materials and methods: Sixty-nine patients with acute (<14 days [n = 35]) or subacute (14–42 days [n = 34]) femoropopliteal bypass occlusions were treated with PMT combined with thrombolysis. Seventy-two patients with acute [n = 40] or subacute [n = 32] femoropopliteal bypass occlusions were treated with thrombolysis alone. The thrombolysis in myocardial infarction (TIMI) classification was used to assess the bypass occlusion. Local thrombolysis time and dosage, reopening time, time in the intensive care unit, necessary surgical re-interventions, and clinical outcome were compared between the 2 groups. Results: The TIMI scores were significantly higher in the PMT plus thrombolysis group than in the thrombolysis group (acute occlusions 1188 versus 935, p < 0.001; subacute occlusions 935 versus 605, p < 0.001). The total urokinase dosage, the total hours of thrombolysis, time in the intensive care unit, and total hospital stay in the acute PMT plus thrombolysis group were significantly lesser than those in the thrombolysis group. After 24 h of treatment, the ankle-brachial index improved in all groups (p < 0.001): in the acute and subacute PMT plus thrombolysis group to 0.63 ± 0.14 and 0.43 ± 0.08, respectively; and in the acute and subacute thrombolysis group to 0.51 ± 0.11 and 0.41 ± 0.04, respectively. Conclusions: PMT combined with thrombolysis is a safe and very effective therapy for acute and subacute femoropopliteal bypass occlusions compared to treatment with thrombolysis alone.

  5. Endovascular gamma irradiation for the prevention restenosis after angioplasty of femoropopliteal de novo stenoses

    The purpose of this study was to investigate the effectiveness and detect side effects of centered, overlapped endovascular gamma irradiation after angioplasty of de novo femoropopliteal stenoses. Thirty patients (age 65.3±9.2 years) with arterial occlusive disease were prospectively enrolled to receive endovascular gamma irradiation (192-iridium, 14 Gy centered at 2 mm vessel wall) immediately after percutaneous transluminal angioplasty (PTA) of femoropopliteal stenoses. Irradiation overlapped dilatation by 1-2 cm at each end. Follow-up involved angiography after 12 months; duplex sonography; and interviews before and after PTA and at 1, 6, and 12 months follow-up. PTA and centered endovascular irradiation were performed successfully in all patients. Three thromboembolic complications occurred during irradiation. Angiographic and clinical follow-up was possible in 28 patients. The angiographic degree of stenosis was 73.8%±16.3% before and 3.6%±23.5% after PTA and was 3.5%±43.7% at the 1-year follow-up. Restenosis (>50%) of the target lesion developed in three patients (10.7%) and edge stenoses (>30%) in nine patients (32.1%). An aneurysm of the irradiated segment in one patient was treated by stenting. The rate of retreatment was 17.9%. The vessel diameter after endovascular gamma irradiation and PTA of femoropopliteal stenoses remained stable. Restenosis, induction of edge stenoses, and aneurysm were reasons for reinterventions. (orig.)

  6. Frequency-Domain Intravascular Optical Coherence Tomography of the Femoropopliteal Artery

    Purpose: Optical coherence tomography (OCT) is a catheter-based imaging method that employs near-infrared light to produce high-resolution intravascular images. The authors report the safety and feasibility and illustrate common imaging findings of frequency-domain OCT (FD-OCT) imaging of the femoropopliteal artery in a series of 20 patients who underwent infrainguinal angioplasty. Methods: After crossing the lesion of interest, OCT was performed with a dextrose saline flush technique with simultaneous obstructive manual groin compression. An automatic pullback FD-OCT device was employed (each scan acquiring 54 mm of vessel lumen in 271 consecutive frames). OCT images were acquired before and after balloon dilatation and following provisional stenting if necessary and were evaluated for baseline characteristics of plaque or in-stent restenosis (ISR), vessel wall trauma after angioplasty, presence of thrombus, stent apposition, and tissue prolapse. Imaging follow-up was not included in this study’s protocol. Results: Twenty-seven obstructive lesions (18 cases of de novo atherosclerosis and 9 of ISR) of the femoropopliteal artery were imaged and 148 acquisitions were analyzed in total. High-resolution intravascular OCT imaging with effective blood clearance was achieved in 93.9%. Failure was mainly attributed to preocclusive proximal lesions and/or collateral flow. Mixed features of lipid pool areas, calcium deposits, necrotic core, and fibrosis were identified in all of the imaged atherosclerotic lesions, whereas ISR was purely fibrotic. After balloon angioplasty, OCT identified extensive intimal tears in all cases and one case of severe dissection that biplane subtraction angiography failed to identify. Conclusions: Infrainguinal frequency-domain optical coherence tomography is safe and feasible and may provide intravascular high-resolution imaging of the femoropopliteal artery during infrainguinal angioplasty procedures.

  7. Coronary Artery Bypass

    ... to 3 days in the Intensive Care Unit (ICU). Life After Bypass After bypass surgery, your doctor will recommend that you join a cardiac rehabilitation program. These programs help you make lifestyle changes ...

  8. Endovascular Therapy for Femoropopliteal Artery Disease and Association of Risk Factors With Primary Patency: The Implication of Critical Limb Ischemia and TASC II C/D Disease.

    Nishibe, Toshiya; Yamamoto, Kiyohito; Seike, Yoshimasa; Ogino, Hitoshi; Nishibe, Masayasu; Koizumi, Jun; Dardik, Alan

    2015-11-01

    The treatment of femoropopliteal artery disease remains controversial, without clear guidelines specifying the indications for endovascular therapy (EVT). Accordingly, we retrospectively examined our experience of using EVT to treat femoropopliteal artery disease. A total of 91 limbs in 82 patients underwent EVT for the treatment of femoropopliteal artery disease. Percutaneous transluminal angioplasty alone was performed in 20 limbs, and additional stenting was performed in 71 limbs. The 1-year primary patency, primary-assisted patency, limb salvage, and survival rates were 76%, 88%, 96%, and 92%, respectively. Multivariate Cox analysis of primary patency showed that critical limb ischemia (CLI; hazard ratio [HR], 2.53; 95% confidence interval [CI], 1.08-5.33; P EVT for femoropopliteal artery disease. PMID:26574486

  9. Semiclosed thromboendoarterectomy on femoro-popliteal tract revisited after a fourteen years experience on 595 cases.

    Vercellio, G; Castelli, P; Coletti, M; Carlesi, R; Agrifoglio, G

    1986-01-01

    In the seventies atherosclerotic femoropopliteal lesions were extensively treated by means of retrograde semiclosed thromboendarterectomy (FP-TEA) an analytic follow-up of cases, until 1980, induced the modification of the indications to FP-TEA. Currently the FP-TEA technique is only employed for patients at the 2nd Fontaine's stage with disabling claudication (generally less than 100 mt) with a good distal run-off (at least 2 tibial vessels patent). The report deals with a series of 595 cases operated in the period January 1971-December 1984. In 45% of cases FP-TEA was associated with a proximal revascularization. In an attempt to focus on the factors that may influence the outcome, the patients operated in 1976, 1980, 1984, were assessed and the results related to clinical stage, angiographic pattern and postoperative treatment. PMID:3721758

  10. Clogging the enrichment bypass

    The issue that has come to be known as the bypass is the latest dispute in the continuing saga of uranium trade between the United States and the Commonwealth of Indepenent States. Bypass deals now being conducted by US utilities have drawn heavy criticism from the US Department of Commerce but are perfectly legal under the terms of the Suspension Agreements. Urged on by the United States Enrichment Corporation, the US DOC intends to stop, or at least severely restrict, bypass deals. Using a recent agreement with Kazakhstan as a case study, this article reviews the implications of such bypass deals

  11. Retrospective Study of Rapid-Exchange Monorail Versus Over-the-Wire Technique for Femoropopliteal Angioplasty

    PurposeThe purpose of this study was to compare procedural outcome of rapid-exchange (RX) monorail versus conventional over-the-wire (OTW) technique for femoropopliteal angioplasty.Materials and MethodsDemographic data, procedure details, angioplasty success, and complications of 328 consecutive percutaneous transluminal angioplasties (PTAs) were collected from a prospective database and retrospectively analyzed. Procedure details included duration of fluoroscopy, area-dose product, amount of contrast agent, sheath sizes, access route, length of stenosis, presence of total occlusion, technical and anatomical success (residual stenosis <30% in the absence of complications), need for bail-out stenting, and periprocedural complications. The RX technique alone was used in 102 of 328 cases (31%); the OTW technique, in 226 of 328 of cases (68%).ResultsTechnical success was 98% for the RX versus 95.4% for the OTW technique (p = 0.2). A significantly greater number of stents had to be implanted due to angioplasty failure when the OTW technique was used (RX, 5.9%; OTW, 13.7%; p = 0.04). There were no significant differences in fluorocopy time, dose-area product, or amount of contrast medium used. The RX system facilitated the use of smaller sheath sizes (5 Fr = 38% and 6 Fr = 59% for RX versus 5 Fr = 16.8% and ≥6 Fr = 82.5% for OTW) but showed only a tendency toward lower overall complication rates (16.6% [17/102] in the RX group versus 19.9% [45/226] in the OTW group; p = 0.09). There was no effect on length of hospitalization. RX monorail systems were not associated with higher procedural costs when compared to conventional OTW technique.ConclusionWe conclude that RX monorail systems seem to enhance the technical success of femoropopliteal angioplasty. Although smaller sheath sizes can be used due to the lower profile of the RX systems, there is only a tendency toward lower complication rates.

  12. Heparin-bonded stent-graft for the treatment of TASC II C and D femoropopliteal lesions: the Viabahn-25 cm trial.

    Zeller, Thomas; Peeters, Patrick; Bosiers, Marc; Lammer, Johannes; Brechtel, Klaus; Scheinert, Dierk; Rastan, Aljoscha; Noory, Elias; Beschorner, Ulrich

    2014-12-01

    Purpose: To confirm the performance and safety of the 25-cm Viabahn endoprosthesis with Propaten bioactive surface when used in the treatment of de novo and/or restenotic TransAtlantic Inter-Society Consensus II C and D lesions of the superficial femoral artery and proximal popliteal artery. Methods: The 25-cm Gore Viabahn Endoprosthesis study (ClinicalTrials.gov identifier NCT01263665) is a prospective, multicenter, single-arm study that enrolled 71 patients (50 men; mean age 66.7 ± 8.34 years) with lifestyle-limiting claudication (Rutherford class 2 to 4) and lesions longer than 20 cm (mean length 26.5 ± 5.31 cm, range 20-40). The majority of lesions (92.9%) were total occlusions. The primary performance outcome was post-deployment stent length within ± 10% of the pre-deployment stent length determined angiographically by quantitative vascular analysis. The primary safety outcome was device- and procedure-related serious adverse events occurring within 30 days of the procedure. The patients underwent follow-up examinations at 1 month and 1 year. Results : The median follow-up was 12.3 months (mean 12.3 ± 0.6). Nine (12.7%) patients discontinued the study due to different reasons including 2 bypass surgeries. Angiography was available in 60 patients to determine the primary performance outcome, which was met in all cases. Two (2.8%) patients experienced a procedure-/device-related adverse event (dissection) during the 30-day follow-up. Kaplan-Meier estimates for 1-year primary and secondary patency were 67.0% [95% confidence interval (CI) 53.5% to 77.3%] and 96.9% (95% CI 88.0% to 99.2%), respectively. Changes in ankle-brachial index and Rutherford category at 1 and 12 months each showed sustained improvement. Conclusion : This study confirms that the 25-cm Viabahn endoprosthesis acutely performs as intended and is safe when used as indicated in complex femoropopliteal lesions. One-year primary and secondary patency rates are satisfying and comparable to

  13. An improved algorithm for femoropopliteal artery centerline restoration using prior knowledge of shapes and image space data

    Rakshe, Tejas; Fleischmann, Dominik; Rosenberg, Jarrett; Roos, Justus E.; Straka, Matus; Napel, Sandy

    2008-01-01

    Accurate arterial centerline extraction is essential for comprehensive visualization in CT Angiography. Time consuming manual tracking is needed when automated methods fail to track centerlines through severely diseased and occluded vessels. A previously described algorithm, Partial Vector Space Projection (PVSP), which uses vessel shape information from a database to bridge occlusions of the femoropopliteal artery, has a limited accuracy in long (>100 mm) occlusions. In this article we intro...

  14. Peripheral vascular disease of iliac and femoro-popliteal arteries. State-of-the-art endoluminal revascularization

    Endoluminal therapy is indicated in lower extremity ischaemia with Fontaine grades IIb, III and IV. In the presence of significant limitations, interventions are carried out even in grade IIa claudicants. In addition to the TASC A and B lesions, TASC C and D lesions are increasingly being treated endoluminally as well. Presently, technical success rates of revascularization procedures are above 90% in the iliac vessels and between 79% and 95% in the femoro-popliteal segments. Concentric, non-calcified iliac stenoses are primarily treated with balloon angioplasty (PTA) followed by optional stenting when necessary. For occlusions and heavily calcified lesions, primary stenting is recommended. Primary PTA is the mainstay of treatment in femoro-popliteal vessels with stents being used as a ''bail-out'' option in case of suboptimal PTA. However, initial reports proving the superiority of primary stenting over PTA with optional stenting have already appeared. Results of PTA with drug-coated balloons for prevention of early restenosis are promising. In the near future, primary PTA with optional stenting in the femoro-popliteal segments may give way to drug-coated balloon angioplasty or primary stenting. (orig.)

  15. An improved algorithm for femoropopliteal artery centerline restoration using prior knowledge of shapes and image space data.

    Rakshe, Tejas; Fleischmann, Dominik; Rosenberg, Jarrett; Roos, Justus E; Straka, Matus; Napel, Sandy

    2008-07-01

    Accurate arterial centerline extraction is essential for comprehensive visualization in CT Angiography. Time consuming manual tracking is needed when automated methods fail to track centerlines through severely diseased and occluded vessels. A previously described algorithm, Partial Vector Space Projection (PVSP), which uses vessel shape information from a database to bridge occlusions of the femoropopliteal artery, has a limited accuracy in long (>100 mm) occlusions. In this article we introduce a new algorithm, Intermediate Point Detection (IPD), which uses calcifications in the occluded artery to provide additional information about the location of the centerline to facilitate improvement in PVSP performance. It identifies calcified plaque in image space to find the most useful point within the occlusion to improve the estimate from PVSP. In this algorithm candidates for calcified plaque are automatically identified on axial CT slices in a restricted region around the estimate obtained from PVSP. A modified Canny edge detector identifies the edge of the calcified plaque and a convex polygon fit is used to find the edge of the calcification bordering the wall of the vessel. The Hough transform for circles estimates the center of the vessel on the slice, which serves as a candidate intermediate point. Each candidate is characterized by two scores based on radius and relative position within the occluded segment, and a polynomial function is constructed to define a net score representing the potential benefit of using this candidate for improving the centerline. We tested our approach in 44 femoropopliteal artery occlusions of lengths up to 398 mm in 30 patients with peripheral arterial occlusive disease. Centerlines were tracked manually by four-experts, twice each, with their mean serving as the reference standard. All occlusions were first interpolated with PVSP using a database of femoropopliteal arterial shapes obtained from a total of 60 subjects. Occlusions

  16. Bypassing damaged nervous tissue

    Shneider, M N

    2016-01-01

    We show the principal ability of bypassing damaged demyelinated portions of nervous tissue, thereby restoring its normal function for the passage of action potentials. We carry out a theoretical analysis on the basis of the synchronization mechanism of action potential propagation along a bundle of neurons, proposed recently in [1]. And we discuss the feasibility of implement a bypass to restore damaged nervous tissue and creating an artificial neuron network.

  17. Prevention of Femoropopliteal In-Stent Restenosis With Cilostazol: A Meta-Analysis.

    Iftikhar, Omer; Oliveros, Karla; Tafur, Alfonso J; Casanegra, Ana I

    2016-07-01

    Severe peripheral artery disease requires revascularization to relieve life-limiting ischemic symptoms. Postrevascularization in-stent restenosis continues to be a problem after femoropopliteal procedures. Our aim was to evaluate the use of cilostazol to prevent in-stent restenosis among patients with lower extremity arterial stenting. We performed a MEDLINE and EMBASE search and reviewed the abstracts and manuscripts following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary efficacy outcome was patency rate after stenting. The odds ratio estimates were pooled using the Mantel-Haenszel random-effects method. We identified 524 studies, and 20 articles were fully abstracted and 4 were included in the meta-analysis. The total number of patients included was 2434. Patients in the cilostazol group had better primary patency rates after endovascular stenting than those not taking cilostazol (odds ratio: 0.55; 95% confidence interval: 0.43-0.71). The use of cilostazol appears to prevent in-stent restenosis of high-risk patients. PMID:26390878

  18. Vibrational angioplasty in recanalization of chronic femoropopliteal arterial occlusions: Single center experience

    Purpose: This prospective study aims to present the overall success rate, safety and long-term outcome of vibrational angioplasty technique, in the treatment of chronic total femoropopliteal occlusions in our institute. Methods: Between October 2000 and December 2008, patients with chronic total femoropoliteal arterial occlusions, treated with vibrational angioplasty during the same session after a failed attempt with conventional recanalization technique, were included. Patient's follow up included serial ankle-brachial index measurements and arterial duplex ultrasound examinations at 1, 3, 6, 12, 24, 36 and 48 months. Results: Twenty-seven patients (16 males and 11 females) and twenty-eight lesions were included in our study. Twenty-five lesions (89.3%) were successfully recanalized. Pain relief was noticed in twenty-one cases. From ten lesions with tissue loss (ulcer or gangrene) in successfully recanalized occlusions, six healed without major, or minor amputation. One non-healing amputation stump was healed after recanalization, without further complications. Four limbs underwent amputation (one minor and three major) despite successful recanalization, however all had an excellent healing of the amputation stump without further complications. The Kaplan–Meier test demonstrated 90%, 85% and 70% amputation-free survival rate at 12, 24 and 36 months, respectively. No major or minor complications were encountered. Conclusions: Vibrational angioplasty is a safe, effective and durable endovascular technique for the treatment of chronic total occlusions in patients with limb ischemia that would be difficult to recanalize using conventional intraluminal techniques

  19. Paclitaxel-Coated Balloons: Review of a Promising Interventional Approach to Preventing Restenosis in Femoropopliteal Arteries.

    Teleb, Mohamed; Wardi, Miraie; Gosavi, Sucheta; Said, Sarmad; Mukherjee, Debabrata

    2016-06-01

    Peripheral arterial disease (PAD), a major cause of morbidity and mortality worldwide, is characterized by intermittent claudication and is associated with chronic diseases such as diabetes and hypertension. The goal of treatment is to address the underlying cause and to modify risk factors. Although medical management is the first-line treatment of PAD, some individuals may have severe symptoms and require revascularization with percutaneous transluminal angioplasty with or without stent placement or surgery. Interventional approaches may, however, be associated with high prevalence of restenosis and subsequent complications such as critical limb ischemia and amputation. Drug-eluting balloons (DEBs) are a new interventional technology with the primary goal of preventing restenosis. We review the clinical trials and studies that assessed the efficacy and safety profile of DEB and will focus on the restenosis rate in femoropopliteal arteries including target lesion revascularization (TLR) and late lumen lesion (LLL) using different modalities of intervention such as stents and DEB. Average data collected from the trials reported included restenosis rate of 25%, 0.3 mm LLL, and 14% reduction in TLR with DEB versus uncoated balloons. Below the knee (BTK) only intervention studies were excluded from this review as endovascular approach is usually reserved for critical limb ischemia for BTK disease. Interventional approach to treat PAD with DEB appears to be a promising technology. Additional larger studies are needed to further define safety, efficacy, and longer term outcome with this novel technology. PMID:27231422

  20. Vibrational angioplasty in recanalization of chronic femoropopliteal arterial occlusions: Single center experience

    Kapralos, Ioannis, E-mail: jkapgr@yahoo.gr [251 Hellenic Air Force General Hospital, Athens (Greece); Kehagias, Elias, E-mail: eliaskmd@yahoo.gr [Interventional Radiology Unit, Department of Radiology, Faculty of Medicine, University of Crete, Heraklion, Crete (Greece); Ioannou, Christos, E-mail: ioannou@med.uoc.g [Faculty of Medicine, University of Crete, Heraklion, Crete (Greece); Bouloukaki, Izolde, E-mail: izolthi@gmail.com [Interventional Radiology Unit, Department of Radiology, Faculty of Medicine, University of Crete, Heraklion, Crete (Greece); Kostas, Theodoros, E-mail: kostasth@mailbox.gr [Faculty of Medicine, University of Crete, Heraklion, Crete (Greece); Katsamouris, Asterios, E-mail: asterios@med.uoc.gr [Faculty of Medicine, University of Crete, Heraklion, Crete (Greece); Tsetis, Dimitrios, E-mail: tsetis@med.uoc.gr [Interventional Radiology Unit, Department of Radiology, Faculty of Medicine, University of Crete, Heraklion, Crete (Greece)

    2014-01-15

    Purpose: This prospective study aims to present the overall success rate, safety and long-term outcome of vibrational angioplasty technique, in the treatment of chronic total femoropopliteal occlusions in our institute. Methods: Between October 2000 and December 2008, patients with chronic total femoropoliteal arterial occlusions, treated with vibrational angioplasty during the same session after a failed attempt with conventional recanalization technique, were included. Patient's follow up included serial ankle-brachial index measurements and arterial duplex ultrasound examinations at 1, 3, 6, 12, 24, 36 and 48 months. Results: Twenty-seven patients (16 males and 11 females) and twenty-eight lesions were included in our study. Twenty-five lesions (89.3%) were successfully recanalized. Pain relief was noticed in twenty-one cases. From ten lesions with tissue loss (ulcer or gangrene) in successfully recanalized occlusions, six healed without major, or minor amputation. One non-healing amputation stump was healed after recanalization, without further complications. Four limbs underwent amputation (one minor and three major) despite successful recanalization, however all had an excellent healing of the amputation stump without further complications. The Kaplan–Meier test demonstrated 90%, 85% and 70% amputation-free survival rate at 12, 24 and 36 months, respectively. No major or minor complications were encountered. Conclusions: Vibrational angioplasty is a safe, effective and durable endovascular technique for the treatment of chronic total occlusions in patients with limb ischemia that would be difficult to recanalize using conventional intraluminal techniques.

  1. The impact of stent implantation on the patency rate of femoropopliteal artery after subintimal angioplasty for occlusive arteriosclerosis

    Objective: To assess the impact of stent implantation on the patency rate of femoropopliteal artery after subintimal angioplasty for occlusive arteriosclerosis. Methods: During the period from January 2007 to May 2009, a total of 43 patients with occlusive femoropopliteal arteriosclerosis (43 diseased legs) were treated in authors' hospital. Of the 43 patients, simple percutaneous subintimal angioplasty was performed in 24 (non-stent group), while percutaneous subintimal angioplasty with subsequent stent implantation was carried out in the remaining 19 (stent group). After the treatment, CTA or Doppler ultrasonic examination was performed to check the results. Interventional therapy was respected in some cases who developed restenosis. Results: The 12-month limb salvage rate was 98%. Perioperative minor complications occurred in 7% of patients (3/43). Two-year mortality rate was 7% (3/43). During the follow-up period, arterial restenosis or occlusion occurred in 22 cases. Three cases in non-stent group developed arterial occlusion within one month after the treatment. Repeated interventional procedure was carried out for 12 diseased legs. The primary patency rates of non-stent group at 6, 12 and 24 months were (83.3±7.6)%, (74.0±9.2)% and (56.1±13.5)%, respectively, while those of stent group were (89.5±7.0)%, (77.5±9.9)% and (32.2±16.6)%, respectively. The primary assisted patency rates at 12 and 24 months in non-stent group were (90.9±6.1)% and (64.2±14.7)%, respectively, while those in stent group were (94.4±5.4)% and (39.0±15.90%, respectively. The difference in both the primary patency rate and primary assisted patency rate between the two groups were of no significance (P>0.05). Cox-regression analysis indicated that the number of patent distal vessels, the type of femoropopliteal occlusive diseases and the history of smoking bore a close relationship to the two-year primary patency rate after subintimal angioplasty (r=-4.417, 2.502, 3.115; SX=1

  2. Oclusão arterial aguda de stent fêmoro-poplíteo Acute femoropopliteal artery stent obstruction

    Fabio Henrique Rossi; Milton Kiyonory Uehara; Juliana Chen; Thiago Emilio Burza Maia; Eduardo Mulinari Darold; Andréia Silveira Martins; Akash Kuzhiparambil Prakasan; Nilo Mitsuro Izukawa

    2009-01-01

    A oclusão aguda de stent fêmoro-poplíteo pode ser causa de isquemia crítica dos membros inferiores. A terapia fibrinolítica pode não ser a forma de tratamento mais indicada para o grupo de pacientes com esse quadro clínico. Neste artigo, apresentamos um caso em que a retirada de um fragmento de stent por endarterectomia tornou possível a revascularização do membro.Femoropopliteal stent obstruction may be responsible for acute lower limb ischemia. Fibrinolytic treatment may not be the best the...

  3. Small parietal thrombi in artificial bypass grafts

    During the last five years, 51 femoro-popliteal polytrafluoroethylene grafts were implanted in patients in the Second Surgical University Clinic, Vienna. In four of these patients an angiogram performed shortly after operation showed numerous small parietal thrombi on the artificial graft, a review of the literature has not shown any similar reports. The clinical importance and consequences of this observation are discussed. (orig.)

  4. Bypass Flow Study

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

  5. Bypass Flow Study

    Richard Schultz

    2011-09-01

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

  6. The Best Bypass Surgery Trial

    Møller, Christian H; Jensen, Birte Østergaard; Gluud, Christian; Perko, Mario J; Lund, Jens T; Andersen, Lars Willy; Madsen, Jan Kyst; Hughes, Pia; Steinbrüchel, Daniel A

    2007-01-01

    Recent trials suggest that off-pump coronary artery bypass grafting (OPCAB) reduces the risk of mortality and morbidity compared with conventional coronary artery bypass grafting (CCAB) using cardiopulmonary bypass. Patients with a moderate- to high-risk of complications after CCAB may have addit...

  7. Cardiopulmonary bypass in pregnancy.

    Pomini, F; Mercogliano, D; Cavalletti, C; Caruso, A; Pomini, P

    1996-01-01

    The cardiopathic patient can sustain acute heart failure during pregnancy. In such cases, if open heart operation is necessary to save the patient's life, the fetus could be seriously compromised after exposure to cardiopulmonary bypass. From 1958 to 1992, 69 reports of cardiac operations during pregnancy with the aid of cardiopulmonary bypass have been published. Maternal mortality was 2.9%. Embryofetal mortality was 20.2%. Examining only the last 40 patients, maternal and embryofetal mortality were 0.0% and 12.5%, respectively. Embryofetal mortality was 24.0% when hypothermia was used, compared with 0.0% while operating in normothermia. Maternal mortality did not change. The use of hypothermia during cardiopulmonary bypass provoked uterine contractions in several patients. Hypothermia decreases O2 exchange through the placenta. Pump flow and mean arterial pressure during cardiopulmonary bypass seem to be the most important parameters that influence fetal oxygenation. We speculate that cardiac operation is not a contraindication to pregnancy prolongation. PMID:8561577

  8. Aortic valve bypass

    Lund, Jens T; Jensen, Maiken Brit; Arendrup, Henrik; Ihlemann, Nikolaj

    2013-01-01

    In aortic valve bypass (AVB) a valve-containing conduit is connecting the apex of the left ventricle to the descending aorta. Candidates are patients with symptomatic aortic valve stenosis rejected for conventional aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI...

  9. Bypassing AMPK Phosphorylation

    Viollet, Benoit; Foretz, Marc; Schlattner, Uwe

    2014-01-01

    AMP-activated protein kinase (AMPK) functions as a signaling hub to balance energy supply with demand. Phosphorylation of activation loop Thr172 has been considered as an essential step in AMPK activation. In this issue of Chemistry & Biology, Scott and colleagues show that the small molecule direct AMPK activator, A-769662, bypasses this phosphorylation event, and acts synergistically with AMP on naive AMPK.

  10. Appearance of femoropopliteal segment aneurysms in patients with abdominal aortic aneurysm

    Maksić Milanko

    2012-01-01

    Full Text Available Background/Aim. To promote better treatment outcome, as well as economic benefit it is very important to find out patients with simultaneous occurrence of both aortic and arterial aneurysms. The aim of this prospective study was to determine the frequency and factors affecting femoropopliteal (F-P segment aneurysms appearance in patients with abdominal aortic aneurysms (AAA. Methods. This study included 70 patients who had underwent elective or urgent surgery of AAA from January 1, 2006 to December 31, 2007. After ultrasonographic examination of F-P segment, all the patients were divided into two groups - those with adjunctive F-P segment aneurysm (n = 20 and the group of 50 patients with no adjunctive F-P segment aneurysm. In both groups demographic characteristics (gender, age, risk factors (diabetes mellitus, elevated serum levels of cholesterol and triglycerides, arterial hypertension, smoking, obesity and cardiovascular comorbidity (cerebrovascular desease, ischemic heart desease were investigated. Results. Twenty (28.57% patients who had been operated on because of AAA, had adjunctive aneurysmal desease of F-P segment. Diabetes was no statistically significantly more present among the patients who, beside AAA, had adjunctive aneurismal desease of F-P segment (χ2 = 0.04; DF = 1; p > 0.05. Also, in both groups there was no statistically significant difference in gender structure (χ2 = 2. 05; DF = 2; p > 0.05, age (χ2 = 5. 46; DF = 1; p > 0.05, total cholesterol level (χ2 = 0.89; DF = 1; p > 0.05 and triglyceride (χ2 = 0.89; DF = 1; p > 0.05 levels, the presence of arterial hypertension (χ2 = 1.38; DF = 2; p > 0.05, smoking (χ2 = 1.74; DF = 1; p > 0.05, obesity (χ2 = 1.76; DF = 1; p > 0.05 and presence of cerebrovascular desease (χ2 = 2.34; DF = 1; p > 0.05. Conversly, ischemic heart desease was statistically significantly more present among the patients who, beside AAA, had adjunctive aneurismal desease of F-P segment (χ2 = 5

  11. Cost-effectiveness analysis of orbital atherectomy plus balloon angioplasty vs balloon angioplasty alone in subjects with calcified femoropopliteal lesions

    Weinstock B

    2014-03-01

    Full Text Available Barry Weinstock,1 Raymond Dattilo,2 Tiffini Diage3 1Orlando Health Heart Institute, Mid-Florida Cardiology Specialists, Orlando, FL, USA; 2Department of Cardiology, St Francis Health Center, Topeka, KS, USA; 3North American Science Association (NAMSA, Sunnyvale, CA, USA Introduction: As cost considerations become increasingly critical when selecting optimal endovascular treatment strategies, a cost-benefit analysis was conducted comparing the Diamondback 360°® Orbital Atherectomy System (OAS (Cardiovascular Systems, Inc., St Paul, MN, USA and balloon angioplasty (BA vs BA alone for treatment of calcified femoropopliteal lesions. Patients and methods: The clinical outcomes from COMPLIANCE 360°, a prospective, multicenter, randomized study comparing OAS+BA vs BA alone for treatment of calcified femoropopliteal lesions, were correlated with cost data and previously published quality of life data. Site of service, hospital charges, and associated medical resource utilization were obtained from Uniform Billing statements for index treatments and associated revascularizations out to 1 year. Hospital costs were estimated using hospital-specific, procedure-specific cost-to-charge ratios. Length of stay and procedural data were collected from participating study sites. Results: Twenty-five subjects with 38 lesions and 25 subjects with 27 lesions were randomized to the OAS+BA and BA-alone groups, respectively. Mean hospital charges (US$51,755 vs US$39,922 and estimated hospital costs (US$15,100 vs US$11,016 were higher for OAS+BA compared with BA alone (not statistically significant. Stent utilization was statistically significantly higher with BA-alone treatment for all subjects (1.1 vs 0.1, P=0.001 and in the subset of subjects with one lesion (1.0 vs 0.1, P<0.00001. There was a significant difference in cost for single-lesion versus multiple-lesion treatment. Using costs and quality-adjusted life years (QALYs for the single-lesion cohort, the 1-year

  12. Mid-Term Outcomes of Endovascular Treatment for TASC-II D Femoropopliteal Occlusive Disease with Critical Limb Ischemia

    PurposeThe purpose of the study was to assess the safety and midterm effectiveness of endovascular treatment in Trans-Atlantic Inter-Society Consensus II (TASC-II) D femoropopliteal occlusions in patients with critical limb ischemia (CLI).MethodsPatients with CLI who underwent endovascular treatment for TASC-D de novo femoropopliteal occlusive disease between September 2008 and December 2013 were selected. Data included anatomic features, pre- and postprocedure ankle-brachial index, duplex ultrasound, and periprocedural complications. Sustained clinical improvement, limb salvage rate, freedom from target lesion revascularization (TLR), and freedom from target extremity revascularization (TER) were assessed by Kaplan–Meier estimation and predictors of restenosis/occlusion with Cox analysis.ResultsThirty-two patients underwent treatment of 35 TASC-D occlusions. Mean age was 76 ± 9. Mean lesion length was 23 ± 5 cm. Twenty-eight limbs (80 %) presented tissue loss. Seventeen limbs underwent treatment by stent, 13 by stent-graft, and 5 by angioplasty. Mean follow-up was 29 ± 20 months. Seven patients required major amputation and six patients died during follow-up. Eighteen endovascular and three surgical TLR procedures were performed due to restenosis or occlusion. Estimated freedom from TLR and TER rates at 2 years were 41 and 76 %, whereas estimated primary and secondary patency rates were 41 and 79 %, respectively.ConclusionsEndovascular treatment for TASC II D lesions is safe and offers satisfying outcomes. This patient subset would benefit from a minimally invasive approach. Follow-up is advisable due to a high rate of restenosis. Further follow-up is necessary to know the long-term efficacy of these procedures

  13. Mid-Term Outcomes of Endovascular Treatment for TASC-II D Femoropopliteal Occlusive Disease with Critical Limb Ischemia

    Torres-Blanco, Álvaro, E-mail: atorres658@yahoo.es; Edo-Fleta, Gemma; Gómez-Palonés, Francisco; Molina-Nácher, Vicente; Ortiz-Monzón, Eduardo [Hospital Universitario Dr. Peset, Department of Angiology, Endovascular and Vascular Surgery (Spain)

    2016-03-15

    PurposeThe purpose of the study was to assess the safety and midterm effectiveness of endovascular treatment in Trans-Atlantic Inter-Society Consensus II (TASC-II) D femoropopliteal occlusions in patients with critical limb ischemia (CLI).MethodsPatients with CLI who underwent endovascular treatment for TASC-D de novo femoropopliteal occlusive disease between September 2008 and December 2013 were selected. Data included anatomic features, pre- and postprocedure ankle-brachial index, duplex ultrasound, and periprocedural complications. Sustained clinical improvement, limb salvage rate, freedom from target lesion revascularization (TLR), and freedom from target extremity revascularization (TER) were assessed by Kaplan–Meier estimation and predictors of restenosis/occlusion with Cox analysis.ResultsThirty-two patients underwent treatment of 35 TASC-D occlusions. Mean age was 76 ± 9. Mean lesion length was 23 ± 5 cm. Twenty-eight limbs (80 %) presented tissue loss. Seventeen limbs underwent treatment by stent, 13 by stent-graft, and 5 by angioplasty. Mean follow-up was 29 ± 20 months. Seven patients required major amputation and six patients died during follow-up. Eighteen endovascular and three surgical TLR procedures were performed due to restenosis or occlusion. Estimated freedom from TLR and TER rates at 2 years were 41 and 76 %, whereas estimated primary and secondary patency rates were 41 and 79 %, respectively.ConclusionsEndovascular treatment for TASC II D lesions is safe and offers satisfying outcomes. This patient subset would benefit from a minimally invasive approach. Follow-up is advisable due to a high rate of restenosis. Further follow-up is necessary to know the long-term efficacy of these procedures.

  14. Coronary Artery Bypass

    Kadri Ceberut

    2011-01-01

    Full Text Available Ancient schwannoma is a rare variant of neural tumors though rarely seen in the thorax. The combination with coronary artery diseases is also rare. Here we describe a 66 year-old male who had undergone one-stage combined surgery for thoracic ancient schwannomas removal and coronary artery disease. The masses were, respectively, 13 cm in the middle mediastinum and 5 cm in diameter originating from the intercostal nerve. The tumors were successfully removed using sternotomy, and then a coronary artery bypass grafting was performed. Here we discuss this rare tumor in relation to the relevant literature.

  15. Spiritual Bypass: A Preliminary Investigation

    Cashwell, Craig S.; Glosoff, Harriet L.; Hammond, Cheree

    2010-01-01

    The phenomenon of spiritual bypass has received limited attention in the transpersonal psychology and counseling literature and has not been subjected to empirical inquiry. This study examines the phenomenon of spiritual bypass by considering how spirituality, mindfulness, alexithymia (emotional restrictiveness), and narcissism work together to…

  16. Cardiopulmonary bypass in pregnancy

    Mukul Chandra Kapoor

    2014-01-01

    Full Text Available Cardiac surgery carried out on cardiopulmonary bypass (CPB in a pregnant woman is associated with poor neonatal outcomes although maternal outcomes are similar to cardiac surgery in non-pregnant women. Most adverse maternal and fetal outcomes from cardiac surgery during pregnancy are attributed to effects of CPB. The CPB is associated with utero-placental hypoperfusion due to a number of factors, which may translate into low fetal cardiac output, hypoxia and even death. Better maternal and fetal outcomes may be achieved by early pre-operative optimization of maternal cardiovascular status, use of perioperative fetal monitoring, optimization of CPB, delivery of a viable fetus before the operation and scheduling cardiac surgery on an elective basis during the second trimester.

  17. Heart bypass surgery - minimally invasive

    ... MIDCAB; Robot assisted coronary artery bypass; RACAB; Keyhole heart surgery ... To perform this surgery: The heart surgeon will make a 3- to 5-inch-long surgical cut in the left part of your chest between your ribs ...

  18. Catheter-directed Thrombolysis with Argatroban and tPA for Massive Iliac and Femoropopliteal Vein Thrombosis

    Sharifi, Mohsen, E-mail: seyedmohsensharifi@yahoo.com [Arizona Cardiovascular Consultants (United States); Bay, Curt [A. T. Still University (United States); Nowroozi, Sasan; Bentz, Suzanne; Valeros, Gayle; Memari, Sara [Arizona Cardiovascular Consultants (United States)

    2013-12-15

    Purpose: Catheter-directed thrombolysis (CDT) is a highly effective approach in the treatment of deep venous thrombosis (DVT). There are no data on the primary use of CDT with argatroban and tissue plasminogen activator (tPA) in patients without heparin-induced thrombocytopenia (HIT). The aim of this study was to evaluate the efficacy and safety of the combined administration of argatroban and tPA during CDT for massive DVT in patients without HIT. Methods: Thirty-three patients with massive symptomatic iliac and femoropopliteal DVT underwent CDT with tPA and argatroban within 28 {+-} 6 h of presentation. The dose of tPA was 0.75-1 mg/h through the infusion port and that of argatroban at 0.3-1 {mu}g/kg/min through the side port of the sheath. The patients were evaluated for the efficacy and safety of CDT and recurrent symptomatic venous thromboembolism (VTE) at a mean follow-up of 22 months. Results: There was no bleeding or iatrogenic pulmonary embolism with the CDT regimen we used. Grade III lysis (complete resolution of thrombus on venography) was achieved in 30 patients (91 %). In 3 patients with additional inferior vena cava filter thrombosis, further thrombectomy of the filter was required. No patient developed recurrent VTE. Conclusion: Concomitant administration of argatroban and tPA is a highly safe and effective regimen for CDT for massive DVT.

  19. Catheter-directed Thrombolysis with Argatroban and tPA for Massive Iliac and Femoropopliteal Vein Thrombosis

    Purpose: Catheter-directed thrombolysis (CDT) is a highly effective approach in the treatment of deep venous thrombosis (DVT). There are no data on the primary use of CDT with argatroban and tissue plasminogen activator (tPA) in patients without heparin-induced thrombocytopenia (HIT). The aim of this study was to evaluate the efficacy and safety of the combined administration of argatroban and tPA during CDT for massive DVT in patients without HIT. Methods: Thirty-three patients with massive symptomatic iliac and femoropopliteal DVT underwent CDT with tPA and argatroban within 28 ± 6 h of presentation. The dose of tPA was 0.75–1 mg/h through the infusion port and that of argatroban at 0.3–1 μg/kg/min through the side port of the sheath. The patients were evaluated for the efficacy and safety of CDT and recurrent symptomatic venous thromboembolism (VTE) at a mean follow-up of 22 months. Results: There was no bleeding or iatrogenic pulmonary embolism with the CDT regimen we used. Grade III lysis (complete resolution of thrombus on venography) was achieved in 30 patients (91 %). In 3 patients with additional inferior vena cava filter thrombosis, further thrombectomy of the filter was required. No patient developed recurrent VTE. Conclusion: Concomitant administration of argatroban and tPA is a highly safe and effective regimen for CDT for massive DVT

  20. Bypass Rewiring and Robustness of Complex Networks

    Park, Junsang

    2016-01-01

    A concept of bypass rewiring is introduced and random bypass rewiring is analytically and numerically investigated with simulations. Our results show that bypass rewiring makes networks robust against removal of nodes including random failures and attacks. Especially, random bypass rewiring connects all nodes except the removed nodes on an even degree infinite network and makes the percolation threshold $0$ for arbitrary occupation probabilities. In our example, the even degree network is more robust than the original network with random bypass rewiring while the original network is more robust than the even degree networks without random bypass. We propose a greedy bypass rewiring algorithm which guarantees the maximum size of the largest component at each step, assuming which node will be removed next is unknown. The simulation result shows that the greedy bypass rewiring algorithm improves the robustness of the autonomous system of the Internet under attacks more than random bypass rewiring.

  1. Technology Solutions Case Study: Preventing Thermal Bypass

    none,

    2012-10-01

    This project highlights the importance of continuous air barriers in full alignment with insulation to prevent thermal bypasses and achieve high energy performance, and recommends use of ENERGY STAR's Thermal Bypass Inspection Checklist.

  2. Nonselective digital subtraction angiography of aortocoronary bypasses

    Intra-arterial DSA was performed on 225 patients with a total of 552 coronary bypasses (515 aorto-coronary venous bypasses and 37 internal mammary artery bypasses). Four hundred and ninety-five bypasses were examined in the four weeks following surgery; of these, 428 (85.9%) were patent. Demonstration of the distal anastomosis was obtained in 40.4% of bypasses of the right anterior interventricular artery and in 36.1% of the right coronary artery, at least in their proximal parts. Bypasses of smaller branches showed filling in 12.8 to 19.2%. Because of the unsatisfactory demonstration of distal vessels by non-selective intra-arterial DSA, this method is suitable only for showing the patency of a bypass in the postoperative phase, but should not be used for investigating cardiac signs and symptoms following a bypass examination. (orig.)

  3. Nitinol stent implantation for femoropopliteal disease in patients on hemodialysis: results of the 3-year retrospective multicenter APOLLON study.

    Fujihara, Masahiko; Higashimori, Akihiro; Kato, Yoshihiro; Taniguchi, Hiromasa; Iwasaki, Yusuke; Amano, Tomonori; Sumiyoshi, Akinori; Nishiya, Daisuke; Yokoi, Yoshiaki

    2016-09-01

    The clinical outcomes of nitinol stents for femoropopliteal arterial (FP) disease in patients on hemodialysis were assessed. Endovascular therapy (EVT) is accepted for symptomatic FP disease. However, the clinical outcomes of patients on dialysis are not well known. A multicenter retrospective study was conducted with data between November 2010 and August 2013. A total of 484 consecutive patients who successfully underwent EVT for FP disease with nitinol stents were recruited and analyzed. Patients were categorized into the hemodialysis group (N = 161) and non-hemodialysis group (N = 323). The primary measure was primary patency verified by duplex ultrasound at a rest peak systolic velocity (PSVR) of >2.5, and secondary measures were freedom from target lesion revascularization (TLR) and major amputation-free survival (AFS). Average follow-up duration was 19.5 ± 13.5 months. The primary patency rate at 3 years was significantly lower in the hemodialysis group than the non-hemodialysis group (33.8 vs. 43.7 %; p = 0.036). Freedom from TLR at 3 years was 55.0 % in the hemodialysis group and 66.1 % in the non-hemodialysis group (p = 0.032). The hemodialysis group showed a significantly lower AFS rate at 3 years than the non-hemodialysis group (86.4 vs. 58.2 %; p < 0.001). In hemodialysis patients, nitinol stent use resulted in a lower patency rate, higher TLR rate, and lower AFS rate compared to non-hemodialysis patients. These data suggest that nitinol stent implantation for FP arteries in hemodialysis patient needs to be reconsidered. PMID:26337619

  4. Ankle-Arm Index, Angiography, and Duplex Ultrasonography After Recanalization of Occlusions in Femoropopliteal Arteries: Comparison of Long-Term Results

    Purpose: Comparison of the relative values of the ankle-arm index (AAI) at rest and after exercise, angiography, and duplex ultrasonography for the follow-up of percutaneous transluminal angioplasty (PTA) in patients with peripheral vascular disease. Methods: Thirty-two patients were prospectively followed after technically and clinically successful PTA of a femoropopliteal occlusion. The patency of the femoropopliteal artery was assessed for 1 year using AAI measurements at rest and after exercise; duplex ultrasonography at 4, 12, 24, 36, and 52 weeks; and angiography at 3 and 12 months after PTA. Results: Patency was highly dependent on the measurement technique. The cumulative patency after 1 year determined with the AAI at rest and during exercise, by angiography, and by duplex ultrasonography was 74%, 19%, 31%, and 32%, respectively. Seventy-five percent of the restenoses occurred at the site of the treated occlusion. Conclusion: Duplex ultrasonography is most suitable for this assessment, as it causes no patient discomfort and the specificity is better than AAI after exercise because vascular disease in other, proximal segments does not interfere with the results

  5. Implantation of the Corinthian IQ stent into the femoropopliteal arteries using 6-F introducer sheaths in antegrade and crossover procedures: midterm results

    Dorffner, Roland; Neumann, Christian; Gergely, Istvan [Department of Radiology, Hospital of the Brothers of St. John, Esterhazystrasse 26, 7000, Eisenstadt (Austria); Renner, Reinhold; Resinger, Mathias [Department of Surgery, Hospital of the Brothers of St. John, Esterhazystrasse 26, 7000, Eisenstadt (Austria); Juhasz, Max [Department of Internal Medicine, Hospital of the Brothers of St. John, Esterhazystrasse 26, 7000, Eisenstadt (Austria); Dorffner, Georg [Department of Medical Cybernetics and Artificial Intelligence, University of Vienna, Freyung 6/2, 1010, Vienna (Austria)

    2003-11-01

    The aim of this study was to evaluate the technical performance of the implantation of the Corinthian IQ stent into the femoropopliteal arteries using 6-F introducer sheaths. Thirty-three lesions (24 stenoses, 9 occlusions) in 32 patients (mean age 67 years) were stented. Selective stent implantation was performed after unsatisfactory percutaneous transluminal angioplasty result with an antegrade access in 21 patients and through a crossover sheath in 11 patients. A total of 36 stents were implanted. Stent delivery was successful in all cases (stent diameter 5 or 6 mm, stent length 11-38 mm). In none of the cases was stent dislodgement from the balloon observed. Stent placement was optimal without residual stenosis in 30 cases. In 1 case the stent was chosen too short requiring implantation of a second stent. In 1 patient distal embolization was observed which was treated with catheter embolectomy. Nine-month primary and secondary patency rates were 79{+-}8.7 and 86{+-}7.7%, respectively. Implantation of the Corinthian IQ stent into the femoropopliteal arteries using 6-F introducer sheaths is safe in antegrade and crossover procedures. (orig.)

  6. Implantation of the Corinthian IQ stent into the femoropopliteal arteries using 6-F introducer sheaths in antegrade and crossover procedures: midterm results

    The aim of this study was to evaluate the technical performance of the implantation of the Corinthian IQ stent into the femoropopliteal arteries using 6-F introducer sheaths. Thirty-three lesions (24 stenoses, 9 occlusions) in 32 patients (mean age 67 years) were stented. Selective stent implantation was performed after unsatisfactory percutaneous transluminal angioplasty result with an antegrade access in 21 patients and through a crossover sheath in 11 patients. A total of 36 stents were implanted. Stent delivery was successful in all cases (stent diameter 5 or 6 mm, stent length 11-38 mm). In none of the cases was stent dislodgement from the balloon observed. Stent placement was optimal without residual stenosis in 30 cases. In 1 case the stent was chosen too short requiring implantation of a second stent. In 1 patient distal embolization was observed which was treated with catheter embolectomy. Nine-month primary and secondary patency rates were 79±8.7 and 86±7.7%, respectively. Implantation of the Corinthian IQ stent into the femoropopliteal arteries using 6-F introducer sheaths is safe in antegrade and crossover procedures. (orig.)

  7. Multimodality imaging of coronary artery bypass grafts

    Salm, Liesbeth Pauline

    2006-01-01

    This thesis describes multiple imaging modalities to examine coronary artery bypass grafts, and the research which was performed to further develop noninvasive imaging techniques to detect stenoses in native coronary arteries and bypass grafts in patients who experienced recurrent chest pain after coronary artery bypass grafting (CABG).

  8. Interventions in Infrainguinal Bypass Grafts

    The interventional radiologist plays an important role in the detection and prevention of infrainguinal bypass failure. Early detection and evaluation of flow-limiting lesions effectively preserve graft (venous bypass and polyester or expanded polytetrafluoroethylene bypass) patency by identifying stenoses before occlusion occurs. Delay in treatment of the at-risk graft may result in graft failure and a reduced chance of successful revascularization. For this reason, surveillance protocols form an important part of follow-up after infrainguinal bypass surgery. As well as having an understanding of the application of imaging techniques including ultrasound, MR angiography, CT angiography and digital subtraction angiography, the interventional radiologist should have detailed knowledge of the minimally invasive therapeutic options. Percutaneous transluminal angioplasty (PTA), or alternatively cutting balloon angioplasty, is the interventional treatment of choice in prevention of graft failure and occlusion. Further alternatives include metallic stent placement, fibrinolysis, and mechanical thrombectomy. Primary assisted patency rates following PTA can be up to 65% at 5 years. When the endovascular approach is unsuccessful, these therapeutic options are complemented by surgical procedures including vein patch revision, jump grafting, or placement of a new graft

  9. Intraarterial digital subtraction angiography of aortofemoral bypasses

    In a retrospective study, 214 digital subtraction angiography (DSA) examinations of aortofemoral and femorocrural bypasses were reviewed. In 90% of cases intravenous DSA was diagnostic for aortofemoral bypasses, and in 95% of cases intrarterial DSA angiograms of excellent image quality were obtained. In 82% arterial stenoses proximal to the bypass, in 62% stenoses distal to the bypass, and in only 15% stenoses involving the bypass itself could be detected. In 54% the bypass was regularly perfused. In 26% a complete occlusion could be seen. All angiograms were obtained after infusion of the low-osmolar nonionic contrast medium Iopromide, 150mg/ml. All examinations were painless, and no heat-induced motion artifacts were registered. No disturbances of vital signs were observed. DSA with a nonionic low-osmolarity contrast medium (Iopromide) is a safe and reliable technique for the examination of all surgical aortofemoral bypasses

  10. Mini cardiopulmonary bypass: Anesthetic considerations

    Alsatli, Raed A.

    2012-01-01

    This review article is going to elaborate on the description, components, and advantages of mini-cardiopulmonary bypass (mini-CPB), with special reference to the anesthetic management and fast track anesthesia with mini-CPB. There are several clinical advantages of mini-CPB like, reduced inflammatory reaction to the pump, reduced need for allogenic blood transfusion and lower incidence of postoperative neurological complications. There are certainly important points that have to be considered...

  11. Epicardial ultrasound in coronary artery bypass surgery

    Budde, R.P.J.

    2005-01-01

    Chapter 1 Coronary artery bypass surgery (CABG) is traditionally performed via a median sternotomy approach on cardiopulmonary bypass (arrested heart). Since the mid 1990ties, beating heart, minimally invasive and even totally endoscopic CABG are (re)explored. In all approaches to CABG, the surgeon may face several intraoperative difficulties: 1. Localization of the target coronary artery for bypass grafting. 2. Selection of the optimal anastomotic site on the target coronary artery. 3. Asses...

  12. Popliteal artery puncture in the assessment of patients with severe leg ischemia

    Agerskov, K; Faris, I; Tønnesen, K H; Kristensen, P; Christensen, S C

    1983-01-01

    Two-plane angiography and direct segmental pressure measurements in the femoral and popliteal arteries and indirectly on the arm and ankle were performed in 101 limbs seeking to establish a relationship between angiographic assessment of the patency of the popliteal artery and the trifurcation...... pressure difference exceeded 10 mmHg in 2/58 limbs (3%). One month following above knee femoropopliteal bypass (48 limbs), patients with a popliteal-ankle difference less than 10 mmHg obtained a significantly higher ankle pressure index (PI 0.86, range 0.56-1.20) (p less than 0.01) than those with a......%). Finally, it was possible to predict the postoperative ankle pressure index significantly from data derived from the pressure measurements....

  13. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... And the bypass vessel is the so-called “internal mammary artery.” That’s an artery, as opposed to ... you very much. -- while I’m preparing the internal mammary artery for bypass. Good. All right. We ...

  14. Epicardial ultrasound in coronary artery bypass surgery

    Budde, R.P.J.

    2005-01-01

    Chapter 1 Coronary artery bypass surgery (CABG) is traditionally performed via a median sternotomy approach on cardiopulmonary bypass (arrested heart). Since the mid 1990ties, beating heart, minimally invasive and even totally endoscopic CABG are (re)explored. In all approaches to CABG, the surgeo

  15. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... as doctors use for this operation is “TECAB,” meaning “Totally Endoscopic Coronary Artery Bypass.” This procedure will ... make sure his vessels are able for bypass, meaning doing the CT angiograph for the peripheral arteries. ...

  16. Atrial fibrillation post cardiac bypass surgery

    Mostafa, Ashraf; EL-Haddad, Mohamed A.; Shenoy, Maithili; Tuliani, Tushar

    2012-01-01

    Atrial fibrillation occurs in 5-40% patients after coronary artery bypass graft surgery. Atrial fibrillation increases mortality and morbidity in the post-operative period. We sought to conduct a comprehensive review of literature focusing on pathophysiology, risk factors, prevention and treatment of post coronary artery bypass graft atrial fibrillation.

  17. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... going to thread that up to the patient’s bypass graft using X-ray, and there you are. So what we’re going to do is manipulate this catheter into actually the artery that leads to the arm, the subclavian, which is where the bypass comes off. Let me just saw it for ...

  18. In situ bypass og diabetes

    Jensen, Leif Panduro; Schroeder, T V; Lorentzen, J E

    1993-01-01

    From 1986 through to 1990 a total of 483 in situ bypass procedures were performed in 444 patients. Preoperative risk-factors were equally distributed among diabetic (DM) and non-diabetic (NDM) patients, except for smoking habits (DM:48%, NDM:64%, p = 0.002) and cardiac disease (DM:45%, NDM:29%, p...... = 0.005). Critical limb-ischaemia was more often present in diabetic than non-diabetic patients (DM:57%, NDM:36%, p = 0.0002). Diabetic patients had a significantly lower distal anastomosis than non-diabetic patients (p = 0.00001). There were no differences among diabetic and non-diabetic patients...... regarding three years primary and secondary patency (58% and 64% respectively), and regarding major amputations. However, the rate of minor amputations was higher in insulin-dependent compared with non-insulin-dependent diabetics, who in turn had a higher rate than non-diabetics (p

  19. Secondary coolant purification system with demineralizer bypass

    Apparatus and method are provided for a nuclear stream supply system for adequately controlling the chemistry of the secondary coolant. The invention includes means for the addition of volatile chemicals, a full flow condensate demineralizer, continuous blowdown capability, radiation detection means, a condensate demineralizer bypass line, and an auxiliary demineralizer bypass line, and an auxiliary demineralizer sized to handle full blowdown flow. The auxiliary demineralizer is cut into the system and the steam generator feedwater flow is bypassed around the full flow condensate demineralizer whenever radioactivity is detected in the secondary coolant

  20. Your diet after gastric bypass surgery

    ... low-fat or nonfat hard cheeses, cottage cheese, milk, and yogurt. After gastric bypass surgery, your body will not absorb some important vitamins and minerals. You will need to take these vitamins and ...

  1. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... perfect bypass. We are often asked how you learn this. Important question. Hours and hours of suturing ... OR-Live” makes it easy for you to learn more. Just click on the “Request information” button ...

  2. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... Artery Bypass June 10, 2009 Welcome to the University of Maryland Medical Center in Baltimore, where you ... to Maryland. Welcome to Baltimore. Welcome to the University of Maryland Medical Center here in OR-26. ...

  3. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... on for coronary surgery. A very durable bypass running here and supplying the chest wall with blood. ... case the branch, the typical branch that is running between the two heart chambers is located more ...

  4. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... is pulsating behind the fascia. Here is some muscle. Here we have the apex or tip of ... tissue. It then turns into the transverse thoracic muscle here. This bypass vessel has an extremely long ...

  5. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... sure that we preserve this bypass vessel very well in order to achieve this. So I go ... French quick-draw Venus cardiac visions cannula as well, which will draw back, go to the heart- ...

  6. Types of Coronary Artery Bypass Grafting

    ... best option for you based on your needs. Traditional Coronary Artery Bypass Grafting Traditional CABG is used when at least one major ... Grafting This type of CABG is similar to traditional CABG because the chest bone is opened to ...

  7. Exhaust gas bypass valve control for thermoelectric generator

    Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter Jacobus; Anderson, Todd Alan

    2012-09-04

    A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

  8. Phrenic Nerve Injury during Coronary Artery Bypass

    Guinn, Gene A.; Beall, Arthur C.; Lamki, Neela; Heibig, Jacques; Thornby, John

    1990-01-01

    After coronary artery bypass, some patients have diaphragmatic elevation, usually on the left side. To test our hypothesis that this phenomenon is due to phrenic nerve injury resulting from either 1) dissection of the proximal portion of the left internal mammary artery or 2) topical cooling of the heart with icy slush, we performed the following 2-part study. First, we reviewed our hospital records of 99 coronary artery bypass patients, 55 of whom had received left internal mammary artery gr...

  9. An experimental study of nerve bypass graft

    XU Jie; LI Xue-shi

    2008-01-01

    Objective: To study the use of a nerve "bypass" graft as a possible alternative to neurolysis or segmental resection with interposition grafting in the treatment of neuroma-in-continuity. Methods: A sciatic nerve crush injury model was established in the Sprague-Dawley rat by compression with a straight hemostatic forceps. Epineurial windows were created proximal and distal to the injury site. An 8-mm segment of radial nerve was harvested and coaptated to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Nerve conduction studies were performed over an 8-week period. Sciatic nerves were then harvested and studied under transmission electron microscopy. Myelinated axon counts were obtained. Results: Nerve conduction velocity was significantly faster in the bypass group than in the control group at 8 weeks (63.57 m/s±5.83 m/s vs. 54.88 m/s±4.79m/s, P<0.01). Myelinated axon counts in distal segments were found more in the experimental sciatic nerve than in the control sciatic nerve. Significant axonal growth was noted in the bypass nerve segment itself. Conclusion: Nerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve.

  10. Low-Molecular-Weight Heparin (Reviparin) Reduces the Incidence of Femoropopliteal In-Stent Stenosis: Preliminary Results of an Ongoing Study

    Purpose: To examine the efficacy of the low-molecular-weight heparin, reviparin, for prevention of femoropopliteal stent restenosis. Methods: Forty-two patients who had implantation of flexible tantalum stents for the treatment of stenosis (n= 24) or occlusion (n= 18) of the femoral (n= 27) or popliteal (n= 15) arteries were included in this study protocol. An intraarterial bolus of 5000 IU heparin was given before percutaneous transluminal angioplasty (PTA), and in the case of stent implantation due to unsuccessful PTA, an additional dose of reviparin (3500 anti-factor Xa IU) was given. Postprocedurally, 10,500 anti-factor Xa IU of reviparin were administered intravenously over 24 hr, followed by 3500 anti-factor Xa IU subcutaneously twice a day for 23 days. Oral aspirin (100 mg/day) was prescribed for the long term. Follow-up criteria (maximum follow-up 37 months) were clinical symptoms, Doppler ankle arm indices, color and duplex sonography, and angiography for suspicion of restenosis. Results: Early stent thromboses were not observed. Overall primary patency rate (PPR) was 88% ± 6.0% (1 year) and 74% ± 10.1% (2 years). Major hemorrhagic complications have not occurred. Conclusion: Reviparin administered in a high dose over a period of 24 days is a safe medication regimen and provides excellent patency rates after stent implantation

  11. Comparison of Immediate and 2-Year Outcomes between Excimer Laser-Assisted Angioplasty with Spot Stent and Primary Stenting in Intermediate to Long Femoropopliteal Disease

    Tien-Yu Wu

    2013-01-01

    Full Text Available Background. To compare the clinical outcomes between excimer laser-assisted angioplasty (ELA with spot stent (group A and primary stenting (group B in intermediate to long femoropopliteal disease. Methods. Outcomes of 105 patients totaling 119 legs treated with two different strategies were analyzed retrospectively in a prospectively maintained database. Results. Baseline characteristics were similar in both groups. Better angiographic results and lesser increase of serum C-reactive protein levels (0.60 ± 0.72 versus 2.98 ± 0.97 mg/dL, P<0.001 after the intervention were obtained in Group B. Group A had inferior 1-year outcomes due to higher rate of binary restenosis (67% versus 32%, P=0.001 and lower rate of primary patency (40% versus 58%, P=0.039. Rates of amputation-free survival, target vessel revascularization, assisted primary patency, and stent fracture at 24 months were similar in both groups (80% versus 82%, P=0.979, 65% versus 45%, P=0.11, 78% versus 80%, P=0.75 and 6.3% versus 6.8%, P=0.71, resp.. Conclusion. Greater vascular inflammation after ELA with spot stent resulted in earlier restenosis and inferior 1-year clinical outcomes than primary stenting. This benefit was lost in the primary stenting group at 2 years due to late catch-up restenosis. Active surveillance with prompt intervention was required to maintain the vessel patency.

  12. Brain microvascular function during cardiopulmonary bypass

    Sorensen, H.R.; Husum, B.; Waaben, J.; Andersen, K.; Andersen, L.I.; Gefke, K.; Kaarsen, A.L.; Gjedde, A.

    1987-11-01

    Emboli in the brain microvasculature may inhibit brain activity during cardiopulmonary bypass. Such hypothetical blockade, if confirmed, may be responsible for the reduction of cerebral metabolic rate for glucose observed in animals subjected to cardiopulmonary bypass. In previous studies of cerebral blood flow during bypass, brain microcirculation was not evaluated. In the present study in animals (pigs), reduction of the number of perfused capillaries was estimated by measurements of the capillary diffusion capacity for hydrophilic tracers of low permeability. Capillary diffusion capacity, cerebral blood flow, and cerebral metabolic rate for glucose were measured simultaneously by the integral method, different tracers being used with different circulation times. In eight animals subjected to normothermic cardiopulmonary bypass, and seven subjected to hypothermic bypass, cerebral blood flow, cerebral metabolic rate for glucose, and capillary diffusion capacity decreased significantly: cerebral blood flow from 63 to 43 ml/100 gm/min in normothermia and to 34 ml/100 gm/min in hypothermia and cerebral metabolic rate for glucose from 43.0 to 23.0 mumol/100 gm/min in normothermia and to 14.1 mumol/100 gm/min in hypothermia. The capillary diffusion capacity declined markedly from 0.15 to 0.03 ml/100 gm/min in normothermia but only to 0.08 ml/100 gm/min in hypothermia. We conclude that the decrease of cerebral metabolic rate for glucose during normothermic cardiopulmonary bypass is caused by interruption of blood flow through a part of the capillary bed, possibly by microemboli, and that cerebral blood flow is an inadequate indicator of capillary blood flow. Further studies must clarify why normal microvascular function appears to be preserved during hypothermic cardiopulmonary bypass.

  13. "Orpheus" cardiopulmonary bypass simulation system.

    Morris, Richard W; Pybus, David A

    2007-12-01

    In this paper we describe a high-fidelity perfusion simulation system intended for use in the training and continuing education of perfusionists. The system comprises a hydraulic simulator, an electronic interface unit and a controlling computer with associated real-time computer models. It is designed for use within an actual operating theatre, or within a specialized simulation facility. The hydraulic simulator can be positioned on an operating table and physically connected to the circuit of the institutional heart-lung machine. The institutional monitoring system is used to display the arterial and central venous pressures, the ECG and the nasopharyngeal temperature using appropriate connections. The simulator is able to reproduce the full spectrum of normal and abnormal events that may present during the course of cardiopulmonary bypass. The system incorporates a sophisticated blood gas model that accurately predicts the behavior of a modern, hollow-fiber oxygenator. Output from this model is displayed in the manner of an in-line blood gas electrode and is updated every 500 msecs. The perfusionist is able to administer a wide variety of drugs during a simulation session including: vasoconstrictors (metaraminol, epinephrine and phenylephrine), a vasodilator (sodium nitroprusside), chronotropes (epinephrine and atropine), an inotrope (epinephrine) and modifiers of coagulation (heparin and protamine). Each drug has a pharmacokinetic profile based on a three-compartment model plus an effect compartment. The simulation system has potential roles in the skill training of perfusionists, the development of crisis management protocols, the certification and accreditation of perfusionists and the evaluation of new perfusion equipment and/or techniques. PMID:18293807

  14. Dynamic Cerebral Autoregulation after Cardiopulmonary Bypass

    Christiansen, Claus Behrend; Berg, Ronan M G; Plovsing, Ronni;

    2016-01-01

    Background Cerebral hemodynamic disturbances in the peri- or postoperative period may contribute to postoperative cognitive dysfunction (POCD) in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). We therefore examined dynamic cerebral autoregulation (d......CA) post-CPB and changes in neurocognitive function in patients that had undergone CABG. Materials and Methods We assessed dCA by transfer function analysis of spontaneous oscillations between arterial blood pressure and middle cerebral artery blood flow velocity measured by transcranial Doppler ultrasound...

  15. Prospective Randomized Study of Sarpogrelate Versus Clopidogrel-based Dual Antiplatelet Therapies in Patients Undergoing Femoropopliteal Arterial Endovascular Interventions: Preliminary Results

    Yue-Xin Chen; Wen-Da Wang; Xiao-Jun Song; Yong-Quan Gu; Hong-Yan Tian; He-Jie Hu; Ji-Chun Zhao

    2015-01-01

    Background:Sarpogrelate is a selective 5-hydroxytryptamine (5-HT) receptor subtype 2A antagonist which blocks 5-HT induced platelet aggregation and proliferation of vascular smooth muscle cells.We compared the efficacy of sarpogrelate-based dual antiplatelet therapies for the prevention of restenosis and target lesion revascularization (TLR) rates comparing with that of clopidogrel after percutaneous endovascular interventions (EVIs) of femoropopliteal (FP) arterial lesions.Methods:This prospective,multicenter,randomized clinical trial recruited a total of 120 patients with successful EVI of FP lesions at seven centers across China between January 2011 and June 2012.Patients were randomized to receive either sarpogrelate (1 00 mg trice daily for 6 months,n =63) or clopidogrel (75 mg once daily for 6 months,n =57).All patients also received oral aspirin (100 mg once daily for 12 months).Clinical follow-up was conducted up to 12 months postprocedure.Results:There was no significant difference between the two groups in basic demographic data.The restenosis rate was higher in the clopidogrel group (22.80%) than in sarpogrelate group (17.50%),but there was no significant difference between these two groups (P =0.465).The TLR rate,ipsilateral amputation rate,mortality in all-cause and bleeding rate were also similar in the two groups (P > 0.05).Conclusions:Aspirin plus sarpogrelate is a comparable antithrombotic regimen to aspirin plus clopidogrel after EVI of FP arterial lesions.Dual antiplatelet therapies might play an important role in preventing restenosis after successful EVI of FP lesions.

  16. Coronary artery bypass surgery without cardiopulmonary bypass: short- and mid-term results.

    Mishra, Y; Mehta, Y; Kohli, V M; Kohli, V; Mairal, M; Mishra, A; Bapna, R K; Trehan, N

    1997-01-01

    From March 1994 to April 1997, 433 patients had undergone coronary artery bypass grafting without cardiopulmonary bypass in our institute. Sixty-eight patients had various organ dysfunctions and/or aortic atheroma or calcification and were regarded as high risk for cardiopulmonary bypass. In 277 patients surgery was performed through midline sternotomy, while in 156 minithoracotomy approach was used. In 361 patients single coronary artery bypass grafting was done, and in 72 two-coronary arteries were bypassed. In 63 patients who had graftable vessels in anterior wall and diffusely diseased ungraftable vessels in posterolateral and/or inferior wall, transmyocardial laser revascularisation was also done along with coronary artery bypass grafting to achieve complete myocardial revascularisation. Nine patients in this series were also subjected to simultaneous carotid endarterectomy along with myocardial revascularisation. In two patients complementary percutaneous transluminal coronary angioplasty of left circumflex coronary artery was done five days after minithoracotomy and left internal mammary artery to left anterior descending coronary artery bypass grafting. Forty-two cases were extubated in operating room. Average blood loss was 260 ml. Six patients were reexplored for postoperative bleeding. Seven patients had perioperative myocardial infarction. One developed neurological complication. Hospital mortality was 2.3 percent (10/433 cases) and four deaths were due to malignant ventricular arrhythmias. Nine patients developed chest wound complications. Average hospital stay after operation was six days, 423 patients were discharged from hospital and all of them were asymptomatic. During three years follow-up (range 3 to 38 months) there were three known cardiac deaths. Ninety percent (391) patients reported to the follow-up clinic and 91 percent of them were angina-free. In patients who were subjected to transmyocardial laser revascularisation along with coronary

  17. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    ROBOT-ASSISTED MINIMALLY INVASIVE CORONARY ARTERY BYPASS SURGERY OPERATION PINNACLEHEALTH HARRISBURG HOSPITAL HARRISBURG, PA 00:00:08 ... Hospital campus. We are going to witness a robot-assisted minimally invasive coronary artery bypass surgery operation. ...

  18. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Full Text Available ROBOT-ASSISTED MINIMALLY INVASIVE CORONARY ARTERY BYPASS SURGERY OPERATION PINNACLEHEALTH HARRISBURG HOSPITAL HARRISBURG, PA 00:00:08 ... Hospital campus. We are going to witness a robot-assisted minimally invasive coronary artery bypass surgery operation. ...

  19. 21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

    2010-04-01

    ... bypass oxygenator. (a) Identification. A cardiopulmonary bypass oxygenator is a device used to exchange gases between blood and a gaseous environment to satisfy the gas exchange needs of a patient during...

  20. Coronary Artery Bypass Graft Surgery (Beyond the Basics)

    ... for people with coronary heart disease is called "percutaneous coronary intervention" (PCI), or "stenting." This involves using a flexible ... artery disease: Coronary artery bypass graft surgery versus percutaneous coronary intervention Coronary artery bypass grafting in patients with cerebrovascular ...

  1. Crioplastia para tratamento da doença arterial fêmoro-poplítea Cryoplasty for the treatment of femoropopliteal arterial disease

    Marco Antonio Lourenço

    2011-09-01

    .BACKGROUND: Endovascular treatment of peripheral arterial disease (PAD presents low morbidity and mortality rates; however, mid and long-term patency rates remain controversial. Cryoplasty was developed as an attempt to resolve the main problems related to angioplasty: dissection, recoil and restenosis. OBJECTIVE: To evaluate clinical results and mid-term patency in patients treated with cryoplasty of femoropopliteal arterial disease. METHODS: Patients with indication for endovascular lower limb revascularization according to Fontaine and Rutherford clinical classifications and to TASC II anatomical classification underwent cryoplasty using the PolarCath® peripheral dilatation balloon catheter. Clinical results and anatomical patency were analyzed by duplex ultrasound scan at follow-up, RESULTS: Ten patients with femoropopliteal arterial disease were treated with cryoplasty. Nine patients presented with intermittent claudication and one patient had an ischemic ulcer. Three patients had class B lesions and seven patients had class A lesions according to the TASC II. Initial technical success was achieved in all patients, and one patient needed stenting during the procedure due to dissection. One patient died due to complications in the postoperative period. Nine patients were followed up for 31.6 months on average (18-35, with primary patency rate of 77.7% and secondary patency rate of 100%. All patients were asymptomatic at the end of this period (Fontaine stage I. CONCLUSIONS: Cryoplasty is a safe technique for the treatment of femoropopliteal arterial disease that presents low morbidity rates, short-term and mid-term results comparable to conventional angioplasty, as well as potential advantages of lower dissection, recoil and mid-term restenosis rates.

  2. Obstructive and enteropathic syndromes after jejunoileal bypass surgery

    Small bowel bypass procedures for morbid obesity have been associated with many postoperative complications. With the use of the Scott procedure, the bypassed or excluded small bowel segment has recently been the focus of 2 syndromes - 'bypass enteritis' and 'defunctioned bowel syndrome'. We describe these postoperative complications and present their significant radiologic features. (orig.)

  3. Obstructive and enteropathic syndromes after jejunoileal bypass surgery

    Karasick, D.; Karasick, S.

    1981-05-15

    Small bowel bypass procedures for morbid obesity have been associated with many postoperative complications. With the use of the Scott procedure, the bypassed or excluded small bowel segment has recently been the focus of 2 syndromes - 'bypass enteritis' and 'defunctioned bowel syndrome'. We describe these postoperative complications and present their significant radiologic features.

  4. Outcomes after off-pump coronary bypass surgery

    Dijk, Diederik van

    2002-01-01

    The complications associated with in coronary artery bypass surgery (CABG) using cardiopulmonary bypass (CPB) have led to a renewed interest in coronary bypass surgery on the beating heart. The primary objective of the Octopus Study was to compare cognitive outcome between patients randomized to off

  5. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is used in the blood pump head and which is cyclically compressed by the pump to cause the blood to...

  6. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood...

  7. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  8. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... completely endoscopic coronary artery bypass grafting procedure using robotics. We call this operation a “TECAB,” “Totally Endoscopic ... scrub nurse, also a lot of experience with robotics now. And Dr. Atiq Rahman, fellow here for ...

  9. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... bypass graft to the LAD. We have a real long-term option. 4 So again, this is under T guidance. Anesthesia tells me that I am in the descending thoracic aorta. That means I’m on the right track. Once that is done then we sequentially ...

  10. Analysis and testing of electrorheological bypass dampers

    Lindler, Jason E.; Wereley, Norman M.

    1998-06-01

    We experimentally validate nonlinear quasi-steady electrorheological (ER) and magnetorheological (MR) damper models, using an idealized Bingham plastic shear flow mechanism, for the flow mode of damper operation. An electrorheological valve or bypass damper was designed, and fabricated using predominantly commercial off-the-shelf hydraulic components. Both the hydraulic cylinder and the bypass duct have cylindrical geometry, and damping forces are developed in the annular bypass via Poiseuille (flow mode) flow. Damper models assume parallel plate geometry. Three nondimensional groups are used for damper analysis, namely, the Bingham number, Bi, the nondimensional plug thickness, (delta) , and the area coefficient defined as the ratio of the piston head area, A(rho ), to the cross-sectional area of the annular bypass, Ad. In the flow mode case, the damping coefficient, which is defined as the ratio of equivalent viscous damping of the Bingham plastic material, Ceq, to the Newtonian viscous damping, C, is a function of the nondimensional plug thickness only. The damper was tested using a mechanical damper dynamometer for sinusoidal stroke of 2 inches, over a range of frequencies below 0.63 Hz. The damping coefficient vs. nondimensional plug thickness diagram was experimentally validated using these data over a range of damper shaft velocities and applied electric field. Because the behaviors of ER and MR fluid are qualitatively similar, these ER damper modeling results may be extended to analysis of flow mode MR dampers.

  11. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... is in place right now. There’s usually some slack or redundancy in the balloon once we initially ... go on bypass, and then it’s without any slack in the right position, and we can inflate ...

  12. Phlegmonous Gastritis Following Coronary Bypass Surgery

    Radhi, J; Kamouna, M; Nyssen, J.

    1999-01-01

    Phlegmonous gastritis is a rare, rapidly progressive and potentially fatal gastric bacterial infection. A case of phlegmonous gastritis following a coronary bypass surgery is described. This condition was not diagnosed premortem due to the nonspecific nature of the gastrointestinal symptoms. Upper gastrointestinal endoscopy may be of value in establishing the diagnosis in emergencies with culture of gastric aspirate and biopsy.

  13. TECAB - Totally Endoscopic Coronary Artery Bypass

    Full Text Available ... coronary artery bypass grafting procedure using robotics. We call this operation a “TECAB,” “Totally Endoscopic Coronary Artery ... see 2 the heart beating behind what we call the “pericardium,” the sack where the heart is ...

  14. Is a fully heparin-bonded cardiopulmonary bypass circuit superior to a standard cardiopulmonary bypass circuit?

    Mahmood, Sarah; Bilal, Haris; Zaman, Mahvash; Tang, Augustine

    2012-01-01

    A best-evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘Is a fully heparin bonded cardiopulmonary bypass circuit superior to a standard cardiopulmonary bypass circuit?’ Altogether more than 792 papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of...

  15. Evaluation of variations of neck to shaft of femur in amputations above knee

    Naraghi M; Hedayatpoor A

    1997-01-01

    In this study, we investigated variations of the angle between neck and shaft of femur after amputation of tigh above the knee. In amputated tigh the angle between neck and shaft of the femur is decreased than normal (nearly 90° degrees) (coax vara). The angle of the normal femur usually increases due to weight bearing (coax valga). In the patients that both tighs have been amputated the changes of the angle are equal.

  16. Evaluation of variations of neck to shaft of femur in amputations above knee

    Naraghi M

    1997-09-01

    Full Text Available In this study, we investigated variations of the angle between neck and shaft of femur after amputation of tigh above the knee. In amputated tigh the angle between neck and shaft of the femur is decreased than normal (nearly 90° degrees (coax vara. The angle of the normal femur usually increases due to weight bearing (coax valga. In the patients that both tighs have been amputated the changes of the angle are equal.

  17. Detecting asymmetries in balance control with system identification: first experimental results from above knee amputees

    Kooij, van der H.; Asseldonk, van E.H.F.; Nederhand, M.J.; Driessen, B.; Helder, J.L.; Gelderblom, G.J.

    2007-01-01

    A prosthetic leg can influence balance in various ways, but not all changes in postural performance can easily be identified with the naked clinical eye. Various studies have shown that dynamic posturography is able to detect more subtle changes in balance control. Here, we describe a modification o

  18. Efficiency Biliopancreatic bypass surgery in bulimia nervosa

    Yu I Yashkov; D K Bekuzarov; A V Nikol'skiy

    2008-01-01

    A clinical significance in the treatment of bulimia nervosa patients with morbid obesity had already been raised [10, 13], but we did not find publications on the effectiveness of bariatric surgery in these cases. There is also information about the possibility of applying the operation bilio-pancreatic bypass, effective in patients with morbid obesity with uncontrolled eating behavior for the treatment of patients with anorexia BILIM not suffering from morbid obesity. In this article the dat...

  19. Analgesic Treatment in Laparoscopic Gastric Bypass Surgery

    Andersen, Lars P H; Werner, Mads U; Rosenberg, Jacob;

    2014-01-01

    This review aimed to present an overview of the randomized controlled trials investigating analgesic regimens used in laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. Literature search was performed in PubMed and EMBASE databases in August 2013 in accordance to PRISMA guidelines. The...... literature search identified nine studies eligible for inclusion. The administration of nonsteroidal anti-inflammatory drugs, local anesthetics (intraperitoneally or subfascially/subcutaneously), transversus abdominis plane block, dexmedetomidine, and ketamine may improve analgesia compared to placebo...

  20. Conduits for Coronary Bypass: Vein Grafts

    Barner, Hendrick B.; Farkas, Emily A.

    2012-01-01

    The saphenous vein has been the principal conduit for coronary bypass grafting from the beginning, circa 1970. This report briefly traces this history and concomitantly presents one surgeons experience and personal views on use of the vein graft. As such it is not exhaustive but meant to be practical with a modest number of references. The focus is that of providing guidance and perspective which may be at variance with that of others and recognizing that there may be many ways to accomplish ...

  1. Conduits for Coronary Bypass: Internal Thoracic Artery

    Barner, Hendrick B.

    2012-01-01

    This second report in the series on coronary artery bypass presents the authors experience and personal views on the internal thoracic artery (ITA) which date to 1966. There has been a very gradual evolution in the acceptance of this conduit which was initially compared with the saphenous vein and viewed as an improbable alternative to it. As is common with concepts and techniques which are 'outside the box' there was skepticism and criticism of this new conduit which was more difficult and t...

  2. Atypical complications of gastric bypass surgery

    Although gastric bypass surgery continues to grow in popularity for weight loss and weight maintenance in the morbidly obese, there has been little attention given to the imaging of complications associated with these surgeries. The purpose of our study is to demonstrate the variety of gastric bypass surgery complications that can be identified radiographically, with attention to the more unusual complications. This study was performed with institutional Internal Review Board approval. We performed a 5-year retrospective review of all patients who had undergone gastric bypass surgery, had complications of the surgery, and had studies performed in our department to image these complications. These studies consisted of contrast fluoroscopy and CT. We identified the more common complications of anastomotic stenoses and anastomotic leaks. We also identified six unusual complications as follow: (1) internal herniation through the small bowel mesentery, (2) internal herniation through the transverse mesocolon, (3) external herniation through the abdominal wall incision, (4) enterocutaneous fistulas, (5) antiperistaltic construction of the Roux-en-Y, and (6) incorrect anstomoses of the Roux limbs resulting in a Roux-en-O configuration. Our findings show that a thorough understanding of expected postoperative bowel configuration is essential in the evaluation of these patients. In addition, fluoroscopic evaluation should assess not only anatomy, but also motility

  3. Vein harvesting and techniques for infrainguinal bypass.

    Albäck, Anders; Saarinen, Eva; Venermo, Maarit

    2016-04-01

    In order to achieve good long term results after bypass surgery, alongside with good inflow and outflow arteries, the bypass graft material also has an important role. The best patency and limb salvage rates are achieved with autologous vein. If great saphenous vein is not available, acceptable long-term results can be achieved with arm veins and lesser saphenous vein. The quality and size of the vein are important. A small-caliber vein, increased wall thickness, postphlebitic changes and varicosities are associated with a risk of early failure. Preoperative vein mapping with ultrasound reduces readmissions and postoperative surgical site infections. During the mapping, the vein to be used and its main tributaries are marked with a permanent marker pen. To reduce wound complication rates we recommend bridged incisions in vein harvesting. Endoscopic vein harvesting seems to have no benefit compared to open techniques in lower limb bypasses, and has been associated with higher risk of primary patency loss at one year. With deep tunneling of the graft the problems caused by wound infection can be avoided. PMID:26837257

  4. Patient's Perception About Coronary Artery Bypass Grafting

    Kelminda Maria Bulhões Mendonça

    2015-10-01

    Full Text Available ABSTRACT OBJECTIVE: The diagnosis of coronary artery disease referred for heart surgery has an important psychological component. The purpose of this study was to access the difficulties experienced by individuals awaiting coronary artery bypass grafting and to determine strategies that facilitate adaptation to a new lifestyle, modified by the disease. METHODS: A qualitative, exploratory study involving patients admitted to a university teaching hospital in the city of Salvador, Bahia, Brazil, awaiting coronary artery bypass grafting. Semi-structured interviews were performed in accordance with a previously defined script based on the study objective. Each transcription was read in its entirety to verify the representativeness, homogeneity and pertinence of the data obtained (pre-analysis, followed by separation of categories of analysis. RESULTS: The descriptions of this study show that patients admitted to the completion of coronary artery bypass grafting experience a wide range of psychological difficulties, considering that surgery acquires interpretations that vary according to individuals' subjectivity. The patients recognized the benefit of being able to discuss their feelings as a means of diminishing their fear and anxiety. CONCLUSION: Helping patients find resources to confront more positively the daily hospitalization is an important aspect for the health care professionals who assist them. This goal can be achieved through modification of the biomedical model of care for a biopsychosocial view. The investment of time and attention is of fundamental importance and aims to overcome existing deficiencies that interfere with the outcome of patients after cardiac surgery.

  5. Dynamic Experimental Study of a Multi—bypass Pulse Tube Refrigerator with Two—bypass Tubes

    YonglinJu; ChaoWang; 等

    1998-01-01

    A dynamic experimental apparatus to measure the instantaneous velocity and pressure in the multibypass pulse tube refrigerator(MPTR) was designed and constructed.Some important experimental results of the instantaneous measurements of the velocity and the pressure in the MPTR with twobypass tubes during actual operation are prsented.The effects of the middle-bypass version on the dynamic pressure and mass flow rate at the cold end of the pulse tube are ev aluated from experimental measurements.DC-flow phenomena are observed in this MPTR.The reasons of the multi-bypass version improved the performance of pulse tube refrigertor are given.

  6. Renal tubular acidosis secondary to jejunoileal bypass for morbid obesity

    Schaffalitzky de Muckadell, O B; Ladefoged, Jens; Thorup, Jørgen Mogens

    1985-01-01

    Renal handling of acid and base was studied in patients with persistent metabolic acidosis 3-9 years after jejunoileal bypass for morbid obesity. Excretion of acid was studied before and after intravenous infusion of NH4Cl and excretion of bicarbonate after infusion of NaHCO3. Bypass patients...... groups. Fractional loss of bicarbonate in urine was higher in controls than in bypass patients. The renal impairment is classified as distal renal tubular acidosis....

  7. Magnetic resonance angiographic assessment after extracranial-intracranial bypass surgery.

    Praharaj, S S; Coulthard, A; Gholkar, A; English, P; Mendelow, A D

    1996-01-01

    Extracranial-intracranial (EC-IC) bypass operation may be performed to augment the distal cerebral circulation. The bypass patency is usually assessed postoperatively with conventional cerebral angiography. Six patients are reported in whom the bypass patency was assessed using magnetic resonance angiography (MRA): Two had intracavernous carotid aneurysms, three had base of skull tumours encompassing the internal carotid artery, and one had occlusion of the right internal carotid artery with ...

  8. Outcomes after off-pump coronary bypass surgery

    van Dijk, Diederik

    2002-01-01

    The complications associated with in coronary artery bypass surgery (CABG) using cardiopulmonary bypass (CPB) have led to a renewed interest in coronary bypass surgery on the beating heart. The primary objective of the Octopus Study was to compare cognitive outcome between patients randomized to off-pump or on-pump CABG. In chapter 2, the literature suggesting that CABG may impair cognitive function is systematically reviewed and chapter 3 describes in detail the rationale and design of the O...

  9. Extra-intracranial standard bypass in the elderly

    Sandow, Nora; von Weitzel-Mudersbach, Paul; Rosenbaum, Sverre;

    2013-01-01

    Patients with chronic atherosclerotic vessel occlusion and cerebrovascular hemodynamic insufficiency may benefit from extra-intracranial (EC-IC) bypass surgery. Due to demographic changes, an increasing number of elderly patients presents with cerebrovascular hemodynamic insufficiency. So far......, little data for EC-IC bypass surgery in elderly patients suffering occlusive cerebrovascular disease are available. We therefore designed a retrospective study to address the question whether EC-IC bypass is a safe and efficient treatment in a patient cohort ≥70 years....

  10. Jejunioleal Bypass Procedures in Morbid Obesity: Preoperative Psychological Findings

    Webb, Warren W.; And Others

    1976-01-01

    Seventy patients who averaged 155 percent overweight and requested jejunioleal bypass surgery as a treatment intervention for morbid obesity were studied preoperatively for prominent psychological characteristics. (Author)

  11. Hormonal and metabolic responses of fetal lamb during cardiopulmonary bypass

    苏肇伉; 周成斌; 张海波; 祝忠群

    2003-01-01

    Objective To study the hormonal and metabolic responses of fetal lamb during cardiopulmonary bypass.Methods Six pregnant ewes underwent fetal cardiopulmonary bypasses with artificial oxygenators and roller pumps for 30 minutes, which maintained the blood gas value at the fetal physiological level. The fetal blood pressure, heart rate, pH value and blood lactate levels were monitored. The levels of catecholamine, cortisol and insulin were measured pre-bypass and then again 30 minutes later. The blood glucose and free fatty acid levels were monitored continuously during the bypass. Fetal hepatic PAS staining was also carried out.Results There were no changes before and during the bypass in fetal blood pressure, heart rate and blood gas. However, pH values decreased and blood lactate levels increased (P<0.05). The fetal catecholamine and cortisol levels increased significantly (P<0.01), while the levels of insulin did not change. The blood glucose and free fatty acid levels increased at the beginning of the bypass (P<0.01), and then gradually slowed down during the bypass. The fetal hepatic PAS staining showed that hepatic glycogen was consumed in large amounts. After 30 minutes of bypass, the fetal lamb would not survive more than 1 hour.Conclusion The fetal lamb has a strong negative reaction to cardiopulmonary bypass.

  12. Cardiac Bypass Pump Flow Management via NIRS Monitoring

    Macnab, Andrew J.; Gagnon, Roy E.; Gagnon, Faith A.; Blackstock, Derek; LeBlanc, Jacques G.

    2003-01-01

    During cardiac surgery, bypass pumps rely on pressure monitors to evaluate flow. We studied whether it would be possible to optimize pump flow by monitoring changes in cerebral cytochrome a,a3 using NIRS to maintain cyt redox status at its pre-bypass level. Method: 18 healthy 7–45 kg swine were placed on bypass for repeated cycles of cooling and re-warming from 36 to 15 to 36°C in 3°C steps. Between each cycle, the swine's bypass pump blood flow rate was adjusted to restore cytochrome redox s...

  13. Obstetrical and neonatal outcomes in women following gastric bypass

    Berlac, Janne Foss; Skovlund, Charlotte Wessel; Lidegaard, Ojvind

    2014-01-01

    OBJECTIVE: To assess obstetrical and neonatal outcomes in women following gastric bypass, compared with adipose women without surgery and with a normal weight control population. DESIGN: Historical controlled cohort study. SETTING: Denmark. POPULATION: All women undergoing gastric bypass during the...... period 1996-2011, and subsequently giving birth. METHODS AND MAIN OUTCOME MEASURES: Obstetrical and neonatal outcomes in women without gastric bypass matched on age, parity, plurality, year, and body mass index, and normal weight women. RESULTS: In 415 women giving birth after gastric bypass we found...

  14. Hemodynamics Simulation of Stenosed Coronary Bypass Graft

    LIU You-jun; QIAO Aike; DU Jian-jun

    2005-01-01

    By means of FEM, the physiological blood flow in coronary bypass graft is simulated. The stenosis in coronary artery is involved in the graft model,and the deformation of graft end to allow the surgical suture with a smaller diameter coronary is taken into consideration. The flow pattern, secondary flow and wall shear stress in the vicinity of anastomosis are analyzed. It is shown that a zone of low wall stress and high wall stress gradient exists downstream the toe. The floor opposed to the anastomosis is an area of high wall stress and high wall stress gradient. Both the toe downstream and the anastomosis bottom floor are prone to intimal hyperplasia.

  15. Flow characteristics in narrowed coronary bypass graft

    Bernad, S. I.; Bosioc, A.; Bernad, E. S.; Petre, I.; Totorean, A. F.

    2016-06-01

    Tortuous saphenous vein graft (SVG) hemodynamics was investigated using computational fluid dynamics (CFD) techniques. Computed tomography (CT) technology is used for non-invasive bypass graft assessment 7 days after surgery. CT investigation shown two regions with severe shape remodelling first is an elbow type contortion and second is a severe curvature with tortuous area reduction. In conclusion, the helical flow induced by vessel torsion may stabilize the blood flow in the distal part of the SVG, reducing the flow disturbance and suppressing the flow separation, but in the distal end of the graft, promote the inflammatory processes in the vessels.

  16. Work on the Geneva motorway bypass

    État de Genève, DCTI, Direction du génie civil

    2006-01-01

    Work on the airport section of the Geneva motorway bypass is continuing and will require the temporary closure of two sliproads allowing traffic to make a U-turn near the airport and the Palexpo exhibition centre. The sliproads on the French and Lausanne sides will be closed until autumn 2006. U-turns will still be possible via clearly marked deviations. For further information: www.autoroute-aeroport.ch We would like to thank you in advance for your understanding. Civil Engineering Department, DCTI, State of Geneva

  17. Impossible Airway Requiring Venovenous Bypass for Tracheostomy

    Johnathan Gardes

    2012-01-01

    Full Text Available The elective surgical airway is the definitive management for a tracheal stenotic lesion that is not a candidate for tracheal resection, or who has failed multiple-tracheal dilations. This case report details the management of a patient who has failed an elective awake tracheostomy secondary to the inability to be intubated as well as severe scar tissue at the surgical site. A combination of regional anesthesia and venovenous bypass is used to facilitate the surgical airway management of this patient. Cerebral oximetry and a multidisciplinary team approach aid in early detection of an oxygenation issue, as well as the emergent intervention that preserved this patient’s life.

  18. Indications and Outcomes of Prophylactic and Therapeutic Extracranial-to-intracranial Arterial Bypass for Cerebral Revascularization

    Emre Gazyakan, MD, MSc

    2015-04-01

    Conclusions: The collaboration of neurosurgeons and plastic surgeons in performing EC-IC bypass can result in excellent outcomes with a high bypass patency rate and few complications, particularly for prophylactic EC-IC bypass.

  19. Efficiency Biliopancreatic bypass surgery in bulimia nervosa

    Yu I Yashkov

    2008-06-01

    Full Text Available A clinical significance in the treatment of bulimia nervosa patients with morbid obesity had already been raised [10, 13], but we did not find publications on the effectiveness of bariatric surgery in these cases. There is also information about the possibility of applying the operation bilio-pancreatic bypass, effective in patients with morbid obesity with uncontrolled eating behavior for the treatment of patients with anorexia BILIM not suffering from morbid obesity. In this article the data of clinical observation of a small sample of patients. As a result, the treatment of these patients found that severe nervous BILIM can be seen as a latent form of morbid obesity. The choice of treatment should depend not only on the initial body weight of the patient, but also on the severity of the nervous BILIM. Unsuccessful attempts at organized-balanced, conservative treatment of patients with severe bulimia nervosa may be considered a variant of surgical treatment, while bilio-pancreatic bypass surgery is considered as the most preferred operation, compared with the installation of the gastric balloon and others. All candidates for surgical treatment of obesity must identify clinical signs of bulimia nervosa, as this may influence the choice of method of operation. Further study of the role of hyperinsulinemia, secretion of ghrelin, leptin, intestinal peptide may contribute to the elucidation of the true causes of bulimia nervosa, probably has a similar origin with morbid obesity.

  20. 21 CFR 870.4420 - Cardiopulmonary bypass cardiotomy return sucker.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass cardiotomy return sucker. 870.4420 Section 870.4420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4420 Cardiopulmonary bypass cardiotomy...

  1. 46 CFR 56.20-20 - Valve bypasses.

    2010-10-01

    ... (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2010-10-01 2010-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...

  2. Reverse bias protected solar array with integrated bypass battery

    Landis, Geoffrey A (Inventor)

    2012-01-01

    A method for protecting the photovoltaic cells in a photovoltaic (PV) array from reverse bias damage by utilizing a rechargeable battery for bypassing current from a shaded photovoltaic cell or group of cells, avoiding the need for a bypass diode. Further, the method mitigates the voltage degradation of a PV array caused by shaded cells.

  3. Rumen bypass nutrients: Manipulation and implications

    The feeds available for ruminants in developing countries are either agro-industrial by-products or specially grown forage crops. Many of these feeds are low in protein and require supplementation with non-protein N (NPN) to maintain efficient rumen function and digestibility. The principles for utilizing high energy, low protein feeds by ruminants are discussed in relation to the supply of NPN, the establishment of efficient rumen function, maximizing feed intake by means of supplements, and increasing total energy and protein intake by using supplements which bypass the rumen. To illustrate it the application of these principles to feeding systems based on molasses, chopped whole sugar cane and derinded sugar cane is discussed. The implications of the principles in increasing the feeding value of straw are also discussed. (author)

  4. Emergent cardiopulmonary bypass during pectus excavatum repair

    Ryan Craner

    2013-01-01

    Full Text Available Pectus excavatum is a chest wall deformity that produces significant cardiopulmonary disability and is typically seen in younger patients. Minimally invasive repair of pectus excavatum or Nuss procedure has become a widely accepted technique for adult and pediatric patients. Although it is carried out through a thoracoscopic approach, the procedure is associated with a number of potential intraoperative and post-operative complications. We present a case of cardiac perforation requiring emergent cardiopulmonary bypass in a 29-year-old male with Marfan syndrome and previous mitral valve repair undergoing a Nuss procedure for pectus excavatum. This case illustrates the importance of vigilance and preparation by the surgeons, anesthesia providers as well as the institution to be prepared with resources to handle the possible complications. This includes available cardiac surgical backup, perfusionist support and adequate blood product availability.

  5. Current status of coronary artery bypass surgery

    CHEN Xin

    2009-01-01

    @@ Surgical revascularization for atherosclerotic heart disease, also called coronary artery bypass grafting (CABG), was first performed in 1962, and is one of the great achievements in medicine. Relief of angina, improvement of exercise tolerance, and the realization of survival benefit have been documented.1 CABG has been used in multi-vessel disease and left main stenosis for over 40 years.2 In the last two decades the mortality of CABG has decreased to less than 2% despite an aging population with increased risk factors. However, percutaneous coronary intervention (PCI), especially with drug-eluting stents, has been challenging CABG, While PCI has improved, CABG has also progressed with better peri-operative management, a higher use of arterial grafting, off-pump surgery, and improved techniques with minimally invasive surgical options.3,4

  6. Innovative Double Bypass Engine for Increased Performance

    Manoharan, Sanjivan

    Engines continue to grow in size to meet the current thrust requirements of the civil aerospace industry. Large engines pose significant transportation problems and require them to be split in order to be shipped. Thus, large amounts of time have been spent in researching methods to increase thrust capabilities while maintaining a reasonable engine size. Unfortunately, much of this research has been focused on increasing the performance and efficiencies of individual components while limited research has been done on innovative engine configurations. This thesis focuses on an innovative engine configuration, the High Double Bypass Engine, aimed at increasing fuel efficiency and thrust while maintaining a competitive fan diameter and engine length. The 1-D analysis was done in Excel and then compared to the results from Numerical Propulsion Simulation System (NPSS) software and were found to be within 4% error. Flow performance characteristics were also determined and validated against their criteria.

  7. Hypoglycaemia after gastric bypass: mechanisms and treatment.

    Ritz, P; Vaurs, C; Barigou, M; Hanaire, H

    2016-03-01

    Hypoglycaemia after gastric bypass can be severe, but is uncommon, and is sometimes only revealed through monitoring glucose concentrations. The published literature is limited by the heterogeneity of the criteria used for diagnosis, arguing in favour of the Whipple triad with a glycaemia threshold of 55 mg/dl as the diagnostic reference. Women who lost most of their excess weight after gastric bypass, long after the surgery was performed, and who did not have diabetes before surgery are at the greatest risk. In this context, hypoglycaemia results from hyperinsulinism, which is either generated by pancreas anomalies (nesidioblastosis) and/or caused by an overstimulation of β cells by incretins, mainly glucagon-like peptide-1 (GLP-1). Glucose absorption is both accelerated and increased because of the direct communication between the gastric pouch and the jejunum. This is a post-surgical exaggeration of a natural adaptation that is seen in patients who have not undergone surgery in whom glucose is infused directly into the jejunum. There is not always a correspondence between symptoms and biological traits; however, hyperinsulinism is constant if hypoglycaemia is severe and there are neuroglucopenic symptoms. The treatment relies firstly on changes in eating habits, splitting food intake into five to six daily meals, slowing gastric emptying, reducing the glycaemic load and glycaemic index of foods, using fructose and avoiding stress at meals. Pharmacological treatment with acarbose is efficient, but other drugs still need to be validated in a greater number of subjects (insulin, glucagon, calcium channel blockers, somatostatin analogues and GLP-1 analogues). Lastly, if the surgical option has to be used, the benefits (efficient symptom relief) and the risks (weight regain, diabetes) should be weighed carefully. PMID:26508374

  8. CFD Analysis of Core Bypass Phenomena

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary

  9. CFD Analysis of Core Bypass Phenomena

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2010-03-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the sector grid can be set as a symmetry boundary

  10. CFD Analysis of Core Bypass Phenomena

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2009-11-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary

  11. Alongshore sediment bypassing as a control on river mouth morphodynamics

    Nienhuis, Jaap H.; Ashton, Andrew D.; Nardin, William; Fagherazzi, Sergio; Giosan, Liviu

    2016-04-01

    River mouths, shoreline locations where fluvial and coastal sediments are partitioned via erosion, trapping, and redistribution, are responsible for the ultimate sedimentary architecture of deltas and, because of their dynamic nature, also pose great management and engineering challenges. To investigate the interaction between fluvial and littoral processes at wave-dominated river mouths, we modeled their morphologic evolution using the coupled hydrodynamic and morphodynamic model Delft3D-SWAN. Model experiments replicate alongshore migration of river mouths, river mouth spit development, and eventual spit breaching, suggesting that these are emergent phenomena that can develop even under constant fluvial and wave conditions. Furthermore, we find that sediment bypassing of a river mouth develops though feedbacks between waves and river mouth morphology, resulting in either continuous bypassing pathways or episodic bar bypassing pathways. Model results demonstrate that waves refracting into the river mouth bar create a zone of low alongshore sediment transport updrift of the river mouth, which reduces sediment bypassing. Sediment bypassing, in turn, controls the river mouth migration rate and the size of the river mouth spit. As a result, an intermediate amount of river discharge maximizes river mouth migration. The fraction of alongshore sediment bypassing can be predicted from the balance between the jet and the wave momentum flux. Quantitative comparisons show a match between our modeled predictions of river mouth bypassing and migration rates observed in natural settings.

  12. Seasonal Variation of Climatological Bypassing Flows around the Tibetan Plateau

    LI Qiang; ZHANG Renhe

    2012-01-01

    The present study investigated diagnostically the seasonal variation of the bypassing flows caused by the splitting effect of the Tibetan Plateau (TP).The relationships among the splitting bypassing flows around the TP to precipitation in China,the westerly jet stream,and the thermal status over the TP are revealed.The bypassing flows occur from the 1st to the 22nd pentad and from the 59th to the 73rd pentad,respectively,and they disappear from the 29th to the 58th pentad.They are strongest in winter from the 1st to the 22nd pentad and from the 59th to the 73rd pentad,respectively.During the rebuilding of the bypassing flows from mid-October to mid-February,they are the main cause of precipitation over southeastern China.The enhancement of the bypassing flow intensity in March cau cause the precipitation to increase in the early stage of the persistent spring rain over southeastern China.From winter to summer,the seasonal transition of the bypassing flows in the lower troposphere precedes that of the westerly jet stream axis in the upper troposphere to the west of the TP by ~4 pentads,while from summer to winter lags by ~4 pentads.The seasonal variation of the thermal status over the TP plays an important role in the bypassing flows around the TP.The strengthening of the heating over the TP weakens the bypassing flows,and the increase in cooling over the TP is related to the rebuilding and strengthening of the bypassing flows.

  13. Coronary bypass using bilateral internal mammary arteries in an achondroplast.

    Alassal, Mohamed Abdulwahab; Youssef, Mostafa; Koudieh, Mohammed

    2015-01-01

    Coronary bypass grafting for ischemic heart disease in achondroplastic dwarfs is very rare. Shortage of veins and inadequate vein quality may cause difficulties during surgery. Only 2 cases of coronary bypass surgery in an achondroplastic dwarf, in which the left internal mammary artery and vein grafts were used, have been reported. We describe the case of a 55-year-old male achondroplastic dwarf who had triple-vessel coronary disease and underwent successful coronary bypass surgery using one saphenous vein graft and bilateral internal mammary artery grafts. The anatomic and surgical challenges in achondroplasia are highlighted. PMID:24887865

  14. Percutaneous transluminal angioplasty after bypass operations on the lower extremities

    To prevent bypass thrombosis, percutaneous transluminal angioplasty (PTA) was performed on 32 stenoses in 25 patients following vascular surgery. Seventeen patients showed 23 stenoses at the level of the anastomoses or in the bypass itself; 8 patients exhibited 9 stenoses proximal or distal to the bypass. Twenty-two patients underwent successful PTA and showed an increase in the ankle/arm Doppler index from 0.38±0.13 to 0.76±0.11 after PTA. The long-term patency rates at 6, 12 and 24 months were 75%, 57% and 39%, respectively. The reason for three unsuccessful PTAs are discussed. (orig.)

  15. Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease

    Møller, Christian H; Penninga, Luit; Wetterslev, Jørn; Steinbrüchel, Daniel A; Gluud, Christian

    2012-01-01

    Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear.......Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear....

  16. Apicoaortic Valve Conduit for a Patient with Aortic Valve Stenosis and Patent Coronary Bypass Grafts Using Cardiopulmonary Bypass.

    Shackelford, Anthony G; Relle, Margaret A; Lombardi, Sarah A

    2015-12-01

    In adults over 65 years of age, aortic valve stenosis has been found to be present in 2-9% within this group. Furthermore, aortic valve replacements in patients whom have had a previous coronary artery bypass grafting surgery have a mortality rate as high as 18%. A non-conventional effective surgical approach of bypassing the aortic valve by inserting an apicoaortic valve conduit (AVC) connecting the left ventricular apex to the descending thoracic aorta has been previously documented. We describe the case of a successful implantation of an AVC in a 64-year-old Caucasian male using cardiopulmonary bypass. PMID:26834287

  17. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... to check their blood sugar several times a day. Other problems that patients with morbid obesity have ... a lap band and he’s discharged the next day. With the gastric bypass, the patient comes in ...

  18. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... and are morbidly obese have higher incidents of heart problems. The other things that we see are ... used for multiple surgical procedures. It’s used for heart procedures, the CABG, coronary artery bypass, valve procedures, ...

  19. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... the gastric bypass Roux-en-Y is a superior procedure than the lap band. That given, we ... of the robot has been shown to be superior to the laparoscopic cases, that this will also ...

  20. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... Anthony Gonzalez, and welcome to South Miami Hospital. We’re here for a live webcast, a fully robotic gastric bypass, as I mentioned, we’re in the operating room at South Miami ...

  1. Severe hypoglycaemia post-gastric bypass requiring partial pancreatectomy

    Patti, M E; McMahon, G; Mun, E C;

    2005-01-01

    AIMS/HYPOTHESIS: Postprandial hypoglycaemia following gastric bypass for obesity is considered a late manifestation of the dumping syndrome and can usually be managed with dietary modification. We investigated three patients with severe postprandial hypoglycaemia and hyperinsulinaemia unresponsive...

  2. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... you a detailed account of how the operation works. During that time, I’d like to answer ... you’ll understand it. Basically, the gastric bypass works on two different principals for weight loss, one ...

  3. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... The feet are in this direction. And the robot is brought and docked over the patient’s body ... this location where I will be using the robot to perform this fully robotic gastric bypass. So ...

  4. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... Health South Florida Miami, FL May 20, 2010 I am Dr. Anthony Gonzalez, and welcome to South ... live webcast, a fully robotic gastric bypass, as I mentioned, we’re in the operating room at ...

  5. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Full Text Available ... needs to be bypassed. So I feel more confident that I can go ahead and start taking ... more so as people become more familiar and confident with their skills. 00:39:31 JOHN PENNOCK, ...

  6. Alveolar proteinosis lung lavage using partial cardiopulmonary bypass.

    Freedman, A P; Pelias, A; Johnston, R F; Goel, I P; Hakki, H I; Oslick, T; Shinnick, J P

    1981-01-01

    An adult case of pulmonary alveolar proteinosis presented with an arterial oxygen tension of 27 mmHg (3.6 kPa) while breathing air. Dangerous hypoxaemia during lung lavage was avoided by using partial cardiopulmonary bypass.

  7. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... Loss Surgery: The Fully Robotic Gastric Bypass Baptist Health South Florida Miami, FL May 20, 2010 I ... study in 1991 at the National Institute of Health in Washington, D.C. And what they looked ...

  8. Antiplatelet therapy at the time of coronary artery bypass grafting

    Kremke, Michael; Jensen, Mariann Tang; Bak, Mikkel; Kristensen, Katrine Lawaetz; Hindsholm, Karsten; Andreasen, Jan Jesper; Hjortdal, Vibeke; Jakobsen, Carl-Johan

    2013-01-01

    OBJECTIVES: The purpose of this multicentre cohort study was to examine the relationship between antiplatelet therapy (APT) at the time of coronary artery bypass grafting (CABG) and postoperative bleeding complications, transfusion requirements and adverse cardiovascular events. METHODS: A matched...

  9. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... later, there was laparoscopic gastric bypass surgery. The learning curve, which is the time that it takes for the surgeon to learn surgery from open to laparoscopic, used to be ...

  10. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... Loss Surgery: The Fully Robotic Gastric Bypass Baptist Health South Florida Miami, FL May 20, 2010 I ... robotic prostatectomy, which is probably the standard of care today for prostate cancer. This is our eighth ...

  11. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass Baptist Health South Florida Miami, FL May 20, 2010 I am Dr. Anthony Gonzalez, and welcome to South Miami Hospital. We’ ...

  12. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... gastrectomy. Another question is, “Does gastric bypass eliminate diabetes?” The morbidly obese patients that we see are those patients that have diabetes mellitus type II, and that’s diabetes associated with ...

  13. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... of reinforce this. This has been a really beautiful case. There’s really no bleeding, even though we ... on BAPTISTHEALTH.NET and joining us for this beautiful fully robotic gastric bypass. I hope that Dr. ...

  14. Association of sex with patency of femorodistal bypass grafts

    Watson, H R; Schroeder, T V; Simms, M H;

    2000-01-01

    There is evidence for superior patency in infra-inguinal bypass procedures in men compared to women. A large, prospectively planned series was investigated in order to confirm this finding and to determine the origin of this difference in outcome....

  15. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... we have an added dimension, and the depth perception is incredible and just aids the surgery a ... later, there was laparoscopic gastric bypass surgery. The learning curve, which is the time that it takes ...

  16. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... gastric bypass. So without further adieu, let me send you out, right outside our doors to my ... everything else that’s going into it, it will send the same signal to the brain that you’ ...

  17. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Full Text Available ... Harrisburg Hospital campus. We are going to witness a robot-assisted minimally invasive coronary artery bypass surgery ... you're starting to do and maybe give a little background on the patient's condition? 00:00: ...

  18. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... later, there was laparoscopic gastric bypass surgery. The learning curve, which is the time that it takes ... that you can do it proficiently; however the learning curve with robotic surgery is much shorter. In ...

  19. Collider bypass diode thermal simulations and measurements for the SSCL

    Rostamzadeh, C.; Tool, G.

    1993-05-01

    Warm bypass diodes will be used as a component of a quench protection system to bypass an exponentially decaying current of 36 sec. time constant and peak current of 7000 A. Temperature excursions due to approximately 252 Kilo Ampere Sec. are studied using ANSYS, a finite element analysis program. A parabolic current waveform of similar energy but higher MIITs (1058 MIIT) was applied to the bypass circuit and temperature excursion was measured at various locations. The procedure of current waveform generation and thermal measurements is illustrated in this paper. A comparison of simulation technique with actual measurements confirms the accuracy of the bypass diode assembly model. This assembly is installed at the SSC half-cell string test facility and results are extremely encouraging.

  20. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... done in two dimensions. Here we have an added dimension, and the depth perception is incredible and ... just a restrictive type of procedure. There’s no combined procedure like with the gastric bypass. So the ...

  1. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... operative procedure, the live procedure, you’ll understand it. Basically, the gastric bypass works on two different ... a small portion of the stomach and divide it from the rest of the stomach, and that’s ...

  2. Value of Optical Bypass in Packet Ring Networks

    2003-01-01

    This paper firstly examines the value of optical bypass scheme in packet ring networks. An Integer Linear Program (ILP) formulation is presented and analytical results under different traffic patterns are given.

  3. Normoxic and Hyperoxic Cardiopulmonary Bypass in Congenital Heart Disease

    2014-01-01

    Cyanotic congenital heart disease comprises a diverse spectrum of anatomical pathologies. Common to all, however, is chronic hypoxia before these lesions are operated upon when cardiopulmonary bypass is initiated. A range of functional and structural adaptations take place in the chronically hypoxic heart, which, whilst protective in the hypoxic state, are deleterious when the availability of oxygen to the myocardium is suddenly improved. Conventional cardiopulmonary bypass delivers hyperoxic...

  4. Electrical failure during cardiopulmonary bypass: a critical moment.

    Durukan, Ahmet Baris; Gurbuz, Hasan Alper; Ozcelik, Gokhan; Yorgancioglu, Cem

    2016-06-01

    Electrical failure during cardiopulmonary bypass is a crisis situation for the cardiac surgical team. Fortunately, it has a low incidence with low morbidity and mortality rates. Notwithstanding, institutional preventative and management measures should be taken. Here, we report a case of electrical failure during cardiopulmonary bypass, which was successfully managed during the surgery, allowing the patient to recover uneventfully. These unwanted complications can only be managed by promoting awareness and putting in place strategies against them. PMID:27516788

  5. Bypass flow computations on the LOFA transient in a VHTR

    Bypass flow in the prismatic gas-cooled very high temperature reactor (VHTR) is not intentionally designed to occur, but is present in the gaps between graphite blocks. Previous studies of the bypass flow in the core indicated that the cooling provided by flow in the bypass gaps had a significant effect on temperature and flow distributions for normal operating conditions. However, the flow and heat transports in the core are changed significantly after a Loss of Flow Accident (LOFA). This study aims to study the effect and role of the bypass flow after a LOFA in terms of the temperature and flow distributions and for the heat transport out of the core by natural convection of the coolant for a 1/12 symmetric section of the active core which is composed of images and mirror images of two sub-region models. The two sub-region models, 9 × 1/12 and 15 × 1/12 symmetric sectors of the active core, are employed as the CFD flow models using computational grid systems of 70.2 million and 117 million nodes, respectively. It is concluded that the effect of bypass flow is significant for the initial conditions and the beginning of LOFA, but the bypass flow has little effect after a long period of time in the transient computation of natural circulation. -- Highlights: • Effect of with/without bypass flow through gaps between hexagonal blocks is studied. • Role of natural convection by the bypass flow after a loss of flow accident. • Two regions of the one-twelfth symmetric sector of the active core are in CFD models. • 70.2 million cell mesh employed for CFD computations with 15 and 9 × 1/12 sectors. • The reference model is based on modular high temperature gas-cooled reactor (MHTGR)

  6. Controllability and Operability Analysis of Heat Exchanger Networks Including Bypasses

    Hernández, S; Balcazar-López, L.; Sánchez-Márquez, J. A.; González-García, G.

    2010-01-01

    In this paper, the influence of bypasses in heat exchanger networks on theoretical control properties and closed-loop behavior was investigated. According to theoretical control properties obtained using the singular value decomposition technique, the presence of bypasses increases flexibility of the heat exchanger network. This result was corroborated using closed-loop dynamic simulations using a proportional integral controller and a proportional integral controller with dynamic estimati...

  7. Coronary artery bypass grafting in an achondroplastic dwarf.

    Balaguer, J M; Perry, D; Crowley, J; Moran, J. M.

    1995-01-01

    To our knowledge, coronary bypass for complications of coronary artery disease in achondroplasia has not previously been described. Achondroplasia, in and of itself, is not a contraindication to coronary bypass. Although the anatomic reserve of saphenous vein is less in achondroplastic dwarfs than in people of normal stature, that vessel and the internal mammary artery can be harvested in routine fashion. A 60-year-old woman with several risk factors for coronary artery disease underwent succ...

  8. Bypass Selection for Control of Heat Exchanger Network

    SUN Lin; LUO Xionglin; HOU Benquan; BAI Yujie

    2013-01-01

    Considering the flexibility and controllability of heat exchanger networks (HENs),bypasses are widely used for effective control of process stream target temperatures.However,the optimal location for the bypass is generally difficult to design with the trade-off between controllability and capital investments.In this paper,based on the steady-state model of heat exchanger networks the optimal bypass location was firstly selected by iteratively calculating the non-square Relative Gain Array (ns-RGA).To simplify the calculation process,rules of bypass selection were also proposed.In order to evaluate this method,then,the structural controllability of heat exchanger networks was analyzed.With both the consideration of the controllability and capital investments,the bypasses locations were finally selected.A case study on the HEN in Crude Distillation Unit was presented in which the ns-RGA and structural controllability were used to select bypasses and also to evaluate the results.

  9. Variations in dietary intake after bypass surgery for obesity. Possible relation to development of fatty liver after jejunoileal bypass

    Rogus, J.; Blumenthal, S.A.

    1981-01-01

    Consumption of nutrients and food energy was compared, with concomitant chemical and radiologic measurements of hepatic fat content, preoperatively and postoperatively in 25 patients who underwent gastric or jejunoileal bypass for obesity. Patients in the two operative groups ingested similar quantities of food before surgery. After surgery, caloric intake from all sources decreased in both groups but to a significantly greater extent in the gastric bypass patients. During the first six months postoperatively, the 13 gastric bypass patients showed no changes in hepatic fat content, whereas substantial increases in liver fat uniformly occurred in the 12 patients who had jejunoileal bypasses. It is suggested that dietary carbohydrate may have contributed to the accretion of liver fat in these 12 patients.

  10. Annular MHD Physics for Turbojet Energy Bypass

    Schneider, Steven J.

    2011-01-01

    The use of annular Hall type MHD generator/accelerator ducts for turbojet energy bypass is evaluated assuming weakly ionized flows obtained from pulsed nanosecond discharges. The equations for a 1-D, axisymmetric MHD generator/accelerator are derived and numerically integrated to determine the generator/accelerator performance characteristics. The concept offers a shockless means of interacting with high speed inlet flows and potentially offers variable inlet geometry performance without the complexity of moving parts simply by varying the generator loading parameter. The cycle analysis conducted iteratively with a spike inlet and turbojet flying at M = 7 at 30 km altitude is estimated to have a positive thrust per unit mass flow of 185 N-s/kg. The turbojet allowable combustor temperature is set at an aggressive 2200 deg K. The annular MHD Hall generator/accelerator is L = 3 m in length with a B(sub r) = 5 Tesla magnetic field and a conductivity of sigma = 5 mho/m for the generator and sigma= 1.0 mho/m for the accelerator. The calculated isentropic efficiency for the generator is eta(sub sg) = 84 percent at an enthalpy extraction ratio, eta(sub Ng) = 0.63. The calculated isentropic efficiency for the accelerator is eta(sub sa) = 81 percent at an enthalpy addition ratio, eta(sub Na) = 0.62. An assessment of the ionization fraction necessary to achieve a conductivity of sigma = 1.0 mho/m is n(sub e)/n = 1.90 X 10(exp -6), and for sigma = 5.0 mho/m is n(sub e)/n = 9.52 X 10(exp -6).

  11. Minimally invasive coronary artery bypass grafting: initial Connecticut experience.

    Tellides, G; Maragh, M R; Smith, J M; Kopf, G S; Ezekowitz, M; Remetz, M; Elefteriades, J A

    1997-03-01

    We report the initial Connecticut experience with minimally invasive coronary artery bypass grafting. This procedure allows bypass grafting to the left anterior descending coronary artery utilizing the internal mammary artery as the conduit. The procedure is minimally invasive because it is performed through a mini-thoracotomy incision in the fourth anterior intercostal space and it is conducted without the use of cardiopulmonary bypass. The procedure has been applied to 13 patients operated between February and October 1996. All but one patient selected were poor candidates for conventional coronary artery bypass surgery because of advanced age (6), chronic renal failure/dialysis/kidney transplant (4), redo status with vulnerable grafts (1), severe peripheral vascular disease (6), severe chronic obstructive pulmonary disease (4). All patients survived operation and were discharged in good condition. Mean postoperative intubation time was seven hours and mean hospital stay was 4.5 days despite the very high pre-existing comorbidity of these patients. All patients are alive at the current follow-up time. Two patients required a conventional bypass procedure for occlusion of the minimally invasive graft, the first because of diffuse disease in the target artery and the second attributable to the technical limitations of minimally invasive coronary artery bypass grafting; both tolerated the subsequent procedure well. All patients are now angina-free. All four grafts studied by routine postoperative angiography were widely patent. Routine post-operative exercise nuclear imaging was normal in an additional patient. This procedure of minimally invasive coronary artery bypass grafting offers significant advantages compared to the conventional bypass procedure (short hospital stay, quick recovery, and, especially, avoidance of cerebrovascular accidents caused by the heart-lung machine). This minimally invasive procedure is expected to apply to a growing percentage of

  12. Infiltration and Bypass Flow of Cracking Puddled Soils

    M.J. Islam

    2004-01-01

    Full Text Available A study of infiltration and bypass flow was conducted in a wet soil bin with three different soils treatments (sandy loam, clay loam and clay soil to determine the swelling behaviour of cracking puddled soils by watering and its impact on bypass flow. Infiltration rate for the soils was recorded after puddling the soils. Then the puddled soils were allowed to dry for a period of up to 15 days. After that the plots were rewetted in order to observe the swelling and bypass behaviour of cracked soils. From this study it is observed that the infiltration rates of puddled soils were very low (0.03-0.05 mm h-1 mainly due to the puddling effect. The study indicates that cracks on puddled soils at 15th day�s of drying are effectively irreversible. The maximum bypass flow was recorded for the clay loam soil. During the first day, the flow rate was extremely high at 313 mm h-1. But this higher rate gradually reduced from the second day and onwards. The bypass flow rate for the clay loam and clay soil was almost same. The study reveals that it is not possible to swell up shrinkage cracks on puddled soils by watering alone. Re-working of the soil is necessary to seal the cracks.

  13. The influence of core bypass flow during SBLOCA

    Many parameters affect the behaviour of a NPP during a Small Break Loss of Coolant Accident (SBLOCA). The bypass flow between the core side and the downcomer is one of them. Different PWRs have different values of core bypass flow. In spite of the complexity of the real situation in the primary system during SBLOCA, some fundamental details of the phenomena can be explained with simplified mathematical models, which relate on basic parameters of the primary coolant. These models define the conditions for loop seal clearance and final results are confirmed with measured values. The analysis presented in the paper refers to Bethsy Test 9.1.b SB LOCA scenario, with variation of core bypass flow. Basic RELAP5 input model calculation results show very good agreement with the experimental data. The core liquid level depression before loop seal clearance is lower in case of smaller core bypass flow. This affects the fuel clad temperature because of different heat transfer mechanisms. Time of loop seal clearance is delayed with larger core bypass flow and consequently lower differential pressure between downcomer and core. (author)

  14. Photovoltaic-module bypass-diode encapsulation. Annual report

    1983-06-20

    The design and processing techniques necessary to incorporate bypass diodes within the module encapsulant are presented in this annual report. A comprehensive survey of available pad-mounted PN junction and Schottky diodes led to the selection of Semicon PN junction diode cells for this application. Diode junction-to-heat spreader thermal resistance measurements, performed on a variety of mounted diode chip types and sizes, have yielded values which are consistently below 1/sup 0/C per watt, but show some instability when thermally cycled over the temperature range from -40 to 150/sup 0/C. Based on the results of a detailed thermal analysis, which covered the range of bypass currents from 2 to 20 amperes, three representative experimental modules, each incorporating integral bypass diode/heat spreader assemblies of various sizes, were designed and fabricated. Thermal testing of these modules has enabled the formation of a recommended heat spreader plate sizing relationship. The production cost of three encapsulated bypass diode/heat spreader assemblies were compared with similarly rated externally-mounted packaged diodes. An assessment of bypass diode reliability, which relies heavily on rectifying diode failure rate data, leads to the general conclusion that, when proper designed and installed, these devices will improve the overall reliability of a terrestrial array over a 20 year design lifetime.

  15. Full turbine bypass system for nuclear power plant

    With the increase in the weight of electric power network, vigilant watch is kept on the toughness of nuclear power plants against disturbances on the side of the network. Basically speaking, it is desirable that reactors continue operation even in case the station is removed from the network due to an outside disturbance. In order to meet this requirement, the application of a full-load turbine bypass system for 1,100-MW-class nuclear power plants has been planned; the development of system components was advanced; the reliability of the full-load turbine bypass system was confirmed through simulation tests. The process of development is outlined here. (author)

  16. Lower leg electrical impedance after distal bypass surgery

    Belanger, G K; Bolbjerg, M L; Heegaard, N H; Wiik, A; Schroeder, T V; Secher, N H

    1998-01-01

    Electrical impedance was determined in 13 patients following distal bypass surgery to evaluate lower leg oedema as reflected by its circumference. Tissue injury was assessed by the plasma concentration of muscle enzymes. After surgery, the volume of the control lower leg increased from 1250 (816...... concentration of troponin I (n = 8). In conclusion, tissue injury was reflected by increases in muscle enzymes in plasma. We found an inverse correlation between lower leg electrical impedance and volume, but the deviation in electrical impedance was approximately twice that of the leg volume. Electrical...... impedance appears to be a useful method for the evaluation of lower leg oedema after distal bypass surgery....

  17. Divertor bypass in the Alcator C-Mod tokamak

    Pitcher, C. S.; LaBombard, B.; Danforth, R.; Pina, W.; Silveira, M.; Parkin, B.

    2001-01-01

    The Alcator C-Mod divertor bypass has for the first time allowed in situ variations to the mechanical baffle design in a tokamak. The design utilizes small coils which interact with the ambient magnetic field inside the vessel to provide the torque required to control small flaps of a Venetian blind geometry. Plasma physics experiments with the bypass have revealed the importance of the divertor baffling to maintain high divertor gas pressures. These experiments have also indicated that the divertor baffling has only a limited effect on the main chamber pressure in C-Mod.

  18. Surgical cartographic navigation system for endoscopic bypass grafting.

    Voruganti, Arun; Mayoral, Rafael; Jacobs, Stephan; Grunert, Ronny; Moeckel, Hendrik; Korb, Werner

    2007-01-01

    Endoscopic bypass grafting with the da Vinci system is still challenging and needs high level of experience and skill of the surgeon. Therefore, it is necessary to support the surgeon with enhanced vision and augmented reality. The augmentation of the patient model into the view of the endoscope is a direct approach to enhance support. The results of a preclinical study are shown in this paper. The method applied is suitable for endoscopic bypass grafting and in general applicable to minimal invasive surgery. The system was designed as an open architecture to facilitate easy transfer of the methodology into other surgical domain applications. PMID:18002243

  19. Managing the Inflammatory Response after Cardiopulmonary Bypass : Review of the Studies in Animal Models

    Liguori, Gabriel Romero; Kanas, Alexandre Fligelman; Moreira, Luiz Felipe Pinho

    2014-01-01

    OBJECTIVE: To review studies performed in animal models that evaluated therapeutic interventions to inflammatory response and microcirculatory changes after cardiopulmonary bypass. METHODS: It was used the search strategy ("Cardiopulmonary Bypass" (MeSH)) and ("Microcirculation" (MeSH) or "Inflammat

  20. Contrast-enhanced cardiac MRI before coronary artery bypass surgery: impact of myocardial scar extent on bypass flow

    The aim of the study was to relate the extent of myocardial late gadolinium enhancement (LGE) in cardiac MRI to intraoperative graft flow in patients undergoing coronary artery bypass graft (CABG) surgery. Thirty-three CAD patients underwent LGE MRI before surgery using an inversion-recovery GRE sequence (turboFLASH). Intraoperative graft flow in Doppler ultrasonography was compared with the scar extent in each coronary vessel territory. One hundred and fourteen grafts were established supplying 86 of the 99 vessel territories. A significant negative correlation was found between scar extent and graft flow (r = -0.4, p -1; p < 0.0001). In summary, the extent of myocardial scar as defined by contrast-enhanced MRI predicts coronary bypass graft flow. Beyond the probability of functional recovery, preoperative MRI might add value to surgery planning by predicting midterm bypass graft patency. (orig.)

  1. Natural headland sand bypassing; towards identifying and modelling the mechanisms and processes

    Bin Ab Razak, M.S.

    2015-01-01

    Natural headland sand bypassing: Towards identifying and modelling the mechanisms and processes contributes to the understanding of the mechanisms and processes of sand bypassing in artificial and non-artificial coastal environments through a numerical modelling study. Sand bypassing processes in general are a relevant but poorly understood topic. This study attempts to link the theory and physics of sand bypassing processes which is significantly important in definition of coastal sedimentar...

  2. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  3. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  4. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  5. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter...

  6. Numerical modelling of bypass transition in turbine cascades

    Louda, P.; Příhoda, Jaromír; Kozel, K.

    Budapest: Budapest University of Technology and Economics, 2015. [International Conference on Fluid Flow Technologies /16./. Budapest (HU), 01.09.2015-04.09.2015] R&D Projects: GA ČR GAP101/12/1271 Institutional support: RVO:61388998 Keywords : 3D turbine cascade * bypass transition model * EARSM turbulence model Subject RIV: BK - Fluid Dynamics

  7. Emergency bypass post percutaneous atrial ablation: a case report.

    Hargrove, M

    2010-11-01

    A 34-year-old male undergoing percutaneous atrial ablation procedure for paroxysmal fibrillation required emergency sternotomy for cardiac tamponade. The patient had been anticoagulated and had received plavix and aspirin prior to and during the ablation procedure. Seven units of red cell concentrate had been transfused in the cardiac catherisation laboratory. On arrival in theatre, the patient was hypotensive, but was awake on induction of anaesthesia. No recordable blood pressure with non-invasive monitoring was observed. A sternotomy was immediately performed and, on evacuation of the pericardium, a bleeding site was not visible. The patient was commenced on cardiopulmonary bypass. Bleeding site was identified and the defect closed. The patient was weaned from cardiopulmonary bypass with minimal inotropic support and made an uneventful recovery. Bypass time was 38 minutes. A literature review showed a 1% incidence of post-ablation bleeding(1). The incidence of reverting to bypass for such an event has not been reported previously. During these procedures, it might be wise to have the cardiothoracic team notified while atrial ablation procedures are being performed in the cardiac catheterization laboratory.

  8. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... doing robotic gastric bypasses, we would do a hybrid. We would do part of it laparoscopically and ... if they’re using the robot, it’s a hybrid procedure. But now we’re doing them fully ...

  9. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Full Text Available ... that we see are those patients that have diabetes mellitus type II, and that’s diabetes associated with obesity. And there’s no question that ... The other question is, “Does gastric bypass eliminate diabetes and does the sleeve?” It’s not the type of -- it’s not actually the type of procedure ...

  10. Cycling firing method for bypass operation of bridge converters

    Zabar, Zivan

    1982-01-01

    The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

  11. Thermal Reliability Study of Bypass Diodes in Photovoltaic Modules (Poster)

    Zhang, Z.; Wohlgemuth, J.; Kurtz, S.

    2013-05-01

    This paper presents the result of high-temperature durability and thermal cycling testing and analysis for the selected diodes to study the detail of the thermal design and relative long-term reliability of the bypass diodes used to limit the detrimental effects of module hot-spot susceptibility.

  12. A device for a noninvasive evaluation of coronary bypass grafts.

    McInerney, J J; Lamser, D G; Herr, M D

    1994-01-01

    A new device is presented for evaluating the patency of coronary bypass grafts. Bypass grafts are located within the chest cavity using a Compton backscatter imaging (CBI) technique that creates frontal plane tomographic images. The tomographic image pixels are mapped into computer memory and displayed. A display pointer is used to mark the position of the bypass graft. The computer uses that information to subsequently position a radiation detector, such that it "looks" at the location of the bypass graft within the closed chest. The patency of the graft is then evaluated by monitoring an X-ray induced iodine fluorescence transient in the graft, subsequent to a peripheral intravenous contrast injection. This imaging and graft evaluation device is relatively inexpensive and its application does not require cutdowns or catheterization. The associated radiation dose is 1/10 to 1/50 of that associated with alternative X-ray graft patency evaluation techniques. Preliminary testing has been performed on mechanical and animal models. PMID:18218544

  13. Integral bypass diodes in an amorphous silicon alloy photovoltaic module

    Hanak, J. J.; Flaisher, H.

    1991-01-01

    Thin-film, tandem-junction, amorphous silicon (a-Si) photovoltaic modules were constructed in which a part of the a-Si alloy cell material is used to form bypass protection diodes. This integral design circumvents the need for incorporating external, conventional diodes, thus simplifying the manufacturing process and reducing module weight.

  14. Clinical benefit of steroid use in patients undergoing cardiopulmonary bypass

    Whitlock, Richard P; Chan, Simon; Devereaux, P J;

    2008-01-01

    We sought to establish the efficacy and safety of prophylactic steroids in adult patients undergoing cardiopulmonary bypass (CPB). We performed a meta-analysis of randomized trials reporting the effects of prophylactic steroids on clinical outcomes after CPB. Outcomes examined were mortality, myo...

  15. Turbulent spots detection during boundary layer by-pass transition

    Jonáš, Pavel; Elsner, W.; Mazur, Oton; Uruba, Václav; Wysocki, M.

    -, č. 80 (2009), s. 16-19. ISSN N R&D Projects: GA AV ČR(CZ) IAA200760614; GA MŠk MEB050810 Institutional research plan: CEZ:AV0Z20760514 Keywords : turbulent spot * boundary layer * by-pass transition * turbulent spot detection Subject RIV: BK - Fluid Dynamics

  16. Bypassing of a barrier by dissociated and superlattice dislocations

    Bhushan, Karihaloo

    1975-01-01

    Very simple procedures are used to calculate the upper and lower bounds for the applied stress required for the leading extended (superlattice) dislocation in a group of n coplanar screw dislocations of like sign with Burgers vector b to bypass a noncoplanar perfect screw dislocation with Burgers...... vector mb (m...

  17. A device for a noninvasive evaluation of coronary bypass grafts

    A new device is presented for evaluating the patency of coronary bypass grafts. Bypass grafts are located within the chest cavity using a Compton Backscatter Imaging (CBI) technique that creates frontal plane tomographic images. The tomographic image pixels are mapped into computer memory and displayed. A display pointer is used to mark the position of the bypass graft. The computer uses that information to subsequently position a radiation detector, such that it looks at the location of the bypass graft within the closed chest. The patency of the graft is then evaluated by monitoring an X-ray induced iodine fluorescence transient in the graft, subsequent to a peripheral intravenous contrast injection. This imaging and graft evaluation device is relatively inexpensive and its application does not require cutdowns or catheterization. The associated radiation dose is 1/10 to 1/50 of that associated with alternative X-ray graft patency evaluation techniques. Preliminary testing has been performed on mechanical and animal models

  18. Simulation and Analysis of the bypass Influences on Tire Noise

    Haichao Zhou

    2014-01-01

    Full Text Available It is a well-known scientific fact that circumferential groove exists great influence on tire noise. Increasing the void can help the rubber blocks to penetrate faster into the underlying water film and improve anti-skid performance, but which gives way to an increased air pumping noise. Therefore, the structure parameters of circumferential grooves play large influence on tire performance. The goal of this present study is using the bypass to change the grooves design and analysis the influence of bypass on tire noise and offer the tire designer a better approach to improve tire comfort ability. By virtual of numerical simulation method, the influence of bypass structure parameters, such as the width of junction pipe, the volume of resonance cavity, on tire noise were analyzed in this study. The result shows that the circumferential grooves with bypass not only bring down pipe resonance noise of circumferential grooves but also decrease far-field radiated noise of tire. Besides, with a certain resonant cavity, the width of junction pipeline between the circumferential grooves and the resonance cavity plays an important role in the improvement of tire noise. Simulation results are in reasonable agreement with experimental results.

  19. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Full Text Available ... PINNACLEHEALTH HARRISBURG HOSPITAL HARRISBURG, PA 00:00:08 JOHN PENNOCK, MD: Welcome this evening to PinnacleHealth Harrisburg ... artery bypass surgery operation. My name is Dr. John Pennock. I'm going to introduce you shortly ...

  20. New air Cherenkov light detectors to study mass composition of cosmic rays with energies above knee region

    Tsunesada, Yoshiki, E-mail: tsunesada@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Katsuya, Ryoichi, E-mail: katsuya@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Mitsumori, Yu; Nakayama, Keisuke; Kakimoto, Fumio; Tokuno, Hisao [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Tajima, Norio [RIKEN, Wako, Saitama 351-0198 (Japan); Miranda, Pedro; Salinas, Juan; Tavera, Wilfredo [Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz (Bolivia, Plurinational State of)

    2014-11-01

    We have installed a hybrid detection system for air showers generated by cosmic rays with energies greater than 3×10{sup 15}eV at Mount Chacaltaya (5200 m above the sea level), in order to study the mass composition of cosmic rays above the knee region. This detection system comprises an air shower array with 49 scintillation counters in an area of 500 m×650 m, and seven new Cherenkov light detectors installed in a radial direction from the center of the air shower array with a separation of 50 m. It is known that the longitudinal development of a particle cascade in the atmosphere strongly depends on the type of the primary nucleus, and an air shower initiated by a heavier nucleus develops faster than that by a lighter primary of the same energy, because of the differences in the interaction cross-section and the energy per nucleon. This can be measured by detecting the Cherenkov radiation emitted from charged particles in air showers at higher altitudes. In this paper we describe the design and performance of our new non-imaging Cherenkov light detectors at Mount Chacaltaya that are operated in conjunction with the air shower array. The arrival directions and energies of air showers are determined by the shower array, and information about the primary masses is obtained from the Cherenkov light data including the time profiles and lateral distributions. The detector consists of photomultiplier tube (PMT), high-speed ADCs, other control modules, and data storage device. The Cherenkov light signals from an air shower are typically 10–100 ns long, and the waveforms are digitized with a sampling frequency of 1 GHz and recorded in situ without long-distance analog signal transfers. All the Cherenkov light detectors record their time-series data by receiving a triggering signal transmitted from the trigger module of the air shower array, which is fired by a coincidence of shower signals in four neighboring scintillation counters. The optical characteristics of the detectors and the control and the data acquisition systems are discussed.

  1. Reoperations for occluded arterial bypasses in the lower limbs

    2006-01-01

    Background We reviewed the outcomes of reoperations for 29 patients (30 limbs) who had undergone occluded arterial bypass in the lower limbs from May 1996 to September 2005. Methods The 30 lower limbs of the 29 patients with arteriosclerotic obstruction received 44 reoperations, including thrombectomy alone (group T, 27) and inflow or outflow reconstruction plus thrombectomy (group C, 17). Among the 17 operations in group C, 17.6% (3/17) were inflow reconstructions involving the axillary-femoral (1), aorta-iliac (1) and aorta-femoral (1) arteries, and 76.4% (13/17) outflow reconstructions involving the femoral-popliteal bypass-tibial (8), femoral-tibial (1), femoral-popliteal bypass-popliteal arteries below the knee (2), and the femoral-popliteal bypass-tibial-peroneal trunk (2). One patient (1 limb) underwent both inflow and outflow reconstructions with an iliac arterial stent and a graft-popliteal anastomosis patch. Polytetrafluoroethylene (PTFE) grafts were used in the inflow or outflow reconstructions abve the knee. Autovenous grafts or autovenously combined PTFE grafts were used in the outflow reconstructions below the knee. Results The percentages of Fontaine stage III and IV before primary operation and reoperation were 60% (18/30) and 86.7% (26/30), respectively (P0.05). Among 42 reoperations, 19 failed within 1 month in groups T (16) and C (3) (P0.05). The rate of limb salvage was 64.29% (18/28). Conclusions The percentages of Fontaine stage III and IV before reoperation may be much higher than those before primary operation. Thrombectomy plus inflow/outflow reconstruction creates patency better than thrombectomy alone for re-occluded bypass.

  2. Glycemic control and outcome related to cardiopulmonary bypass.

    Thiessen, Steven; Vanhorebeek, Ilse; Van den Berghe, Greet

    2015-06-01

    Perioperative hyperglycemia, aggravated by cardiopulmonary bypass, is associated with adverse outcome in adult and pediatric patients. Whereas hyperglycemia was originally perceived as an adaptive response to surgical stress, it is now clear that glycemic control is a strategy to reduce adverse outcomes after cardiac surgery and cardiopulmonary bypass. The optimal blood glucose target, whether or not glycemic control should be initiated already intraoperatively, and whether or not perioperative glucose administration affects the impact of glycemic control on ischemia-reperfusion damage remain open questions. Hypoglycemia, the risk of which is increased with glycemic control, is also associated with adverse outcomes. However, it remains controversial whether brief episodes of hypoglycemia, rapidly corrected during glycemic control, have adverse effects on outcome. This review gives an overview of the currently available literature on glycemic control during and after cardiac surgery and focuses on the indicated open questions about this intervention for this specific patient population. PMID:26060029

  3. Arteriovenous fistulas aggravate the hemodynamic effect of vein bypass stenoses

    Nielsen, T G; Djurhuus, C; Pedersen, Erik Morre; Laustsen, J; Hasenkam, J M; Schroeder, Torben Veith

    1996-01-01

    PURPOSE: The purpose of this study was to assess the impact of arteriovenous fistulas combined with varying degrees of stenosis on distal bypass hemodynamics and Doppler spectral parameters. METHODS: In an in vitro flow model bypass stenoses causing 30%, 55%, and 70% diameter reduction were induced...... the systolic pressure drop from 31% to 48% and had significant impact on all waveform parameters. CONCLUSIONS: Distal arteriovenous fistulas enhance pressure loss across stenoses and affect downstream velocity waveform configuration. The presence of a combined fistula and a stenosis mimics the distal...... 10 cm upstream of a fistula with low outflow resistance. Flow and intraluminal pressure were measured proximal to the stenosis and downstream of the fistula. The waveform parameters peak systolic velocity, end-diastolic velocity, pulsatility index, and pulse rise time were determined from midstream...

  4. Analyses of 1/15 scale Creare bypass transient experiments

    RELAP4 analyses of several 1/15 scale Creare H-series bypass transient experiments have been done to investigate the effect of using different downcomer nodalizations, physical scales, slip models, and vapor fraction donoring methods. Most of the analyses were thermal equilibrium calculations performed with RELAP4/MOD5, but a few such calculations were done with RELAP4/MOD6 and RELAP4/MOD7, which contain improved slip models. In order to estimate the importance of nonequilibrium effects, additional analyses were performed with TRAC-PD2, RELAP5 and the nonequilibrium option of RELAP4/MOD7. The purpose of these studies was to determine whether results from Westinghouse's calculation of the Creare experiments, which were done with a UHI-modified version of SATAN, were sufficient to guarantee SATAN would be conservative with respect to ECC bypass in full-scale plant analyses

  5. Bilateral Internal Thoracic Artery Configuration for Coronary Artery Bypass Surgery

    Boodhwani, Munir; Hanet, Claude; de Kerchove, Laurent; Navarra, Emiliano; Astarci, Parla; Noirhomme, Philippe; El Khoury, Gebrine

    2016-01-01

    Background— Bilateral internal thoracic arteries (BITA) have demonstrated superior patency and improved survival in patients undergoing coronary artery bypass grafting. However, the optimal configuration for BITA utilization and its effect on long-term outcome remains uncertain. Methods and Results— We randomly assigned 304 patients undergoing coronary artery bypass grafting using BITA to either in situ or Y grafting configurations. The primary end point was 3-year angiographic patency. Secondary end points included major adverse cardiac and cerebrovascular events (ie, death from any cause, stroke, myocardial infarction, or repeat revascularization) at 7 years. More coronary targets were able to be revascularized using internal thoracic arteries in patients randomized to Y grafting versus in situ group (3.2±0.8 versus 2.4±0.5 arteries/patient; PURL: http://www.clinicaltrials.gov. Unique identifier: NCT01666366. PMID:27406988

  6. Access pricing, bypass and universal service in post

    Armstrong, Mark

    2006-01-01

    A postal regulator typically faces two issues which make the design of efficient access pricing especially difficult and which complicate the process of liberalizing the industry. First, universal service obligations, together with the presence of fixed costs, require retail prices to depart from the underlying marginal costs of the incumbent provider. Second, competing firms may be able to bypass the incumbent’s delivery network. Within a simple and stylized framework, this note ...

  7. Effects of Deep Breathing Exercises after Coronary Artery Bypass Surgery

    Westerdahl, Elisabeth

    2004-01-01

    Deep breathing exercises are widely used in the postoperative care to prevent or reduce pulmonary complications, but no scientific evidence for the efficacy has been found after coronary artery bypass grafting (CABG) surgery. The aim of the thesis was to describe postoperative pulmonary function and to evaluate the efficacy of deep breathing exercises performed with or without a blow bottle device for positive expiratory pressure (PEP) 10 cmH2O or an inspiratory resistance-positive expirator...

  8. An Efficient Bypassing Void Routing Algorithm for Wireless Sensor Network

    2015-01-01

    Since the sensor node’s distribution in a wireless sensor network (WSN) is irregular, geographic routing protocols using the greedy algorithm can cause local minima problem. This problem may fail due to routing voids and lead to failure of data transmission. Based on the virtual coordinate mapping, this paper proposes an efficient bypassing void routing protocol to solve the control packet overhead and transmission delay in routing void of WSN, which is called EBVRPVCM. The basic idea is to t...

  9. Constitutive modeling of coronary artery bypass graft with incorporated torsion

    Horný, L.; Chlup, Hynek; Žitný, R.; Adámek, T.

    2009-01-01

    Roč. 49, č. 2 (2009), s. 273-277. ISSN 0543-5846 R&D Projects: GA ČR(CZ) GA106/08/0557 Institutional research plan: CEZ:AV0Z20760514 Keywords : coronary artery bypass graft * constitutive model * digital image correlation Subject RIV: BJ - Thermodynamics Impact factor: 0.439, year: 2009 http:// web .tuke.sk/sjf-kamam/mmams2009/contents.pdf

  10. Coronary Artery Bypass Surgery - Multiple Languages: MedlinePlus

    ... Chinese - Simplified (简体中文) Chinese - Traditional (繁體中文) French (français) Hindi (हिन्दी) Japanese (日本語) Korean (한국어) Russian (Русский) ... coronarien - français (French) Bilingual PDF Health Information Translations Hindi (हिन्दी) Coronary Artery Bypass Surgery हिन्दी ( ...

  11. CULTURAL DIAGNOSIS AND BYPASSING; THE EFFECT ON SUCCESSFUL INTERNATIONALIZATION

    Andrews Adugudaa Akolaa

    2012-01-01

    Globalization and its effect on business continue to propel firms to look beyond local markets for opportunities for market development and as a source of growth. However, Cultural differences in various markets continue to exert enormous pressure on international market operations as a result of cultural bypassing or misdiagnosis and this requires international marketers to undertake robust cultural analysis to ensure successful market servicing strategies. This paper reviews and discusses t...

  12. Adherence to treatment after coronary bypass surgery: Psychological aspects

    Maria V. Iakovleva

    2016-01-01

    Poor adherence to treatment is a problem of great importance and striking magnitude. Its consequences are increased health care costs and poor health outcomes. It defined the objective of this research, which is the study of psychological characteristics of patients with different degrees of adherence to rehabilitation treatment after coronary bypass surgery. Ninety male and female patients with CHD, aged 46---71, were examined. The study was carried out using the questionnaire of wa...

  13. Successful cardiopulmonary bypass in diabetics with anaphylactoid reactions to protamine.

    Walker, W. S.; Reid, K G; Hider, C F; Davidson, I. A.; Boulton, F. E.; Yap, P L

    1984-01-01

    Two insulin dependent diabetics with previous anaphylactic like (anaphylactoid) reactions to protamine underwent successful cardiopulmonary bypass for coronary artery surgery. Platelet concentrates instead of protamine were used to neutralise their systemic heparinisation. In both cases the anaphylactoid reactions first became apparent after administration of protamine sulphate at the end of cardiac catheterisation. These cases show that adverse reactions to protamine need not be a contraindi...

  14. Immunocytochemical features of obstructed saphenous vein coronary artery bypass grafts.

    Brody, J I; Pickering, N J; Fink, G B

    1989-01-01

    The peroxidase-immunoperoxidase immunocytochemical method was used on 27 saphenous vein coronary artery bypass grafts, which had been resected because of recurrent angina, to identify in situ cellular and humoral elements possibly associated with graft occlusion. Immunostaining was performed on paraffin wax embedded control saphenous vein and graft sections incubated directly with primary antibodies against von Willebrand antigen (vWFAg), fibronectin, fibrinogen, leucocyte common antigen (LCA...

  15. Factors influencing early results of femoro-femoral crossover bypass

    Đorić Predrag

    2011-01-01

    Full Text Available Introduction. Femoro-femoral crossover bypass is an extraanatomic reconstruction used for revascularization of lower limb with contralatateral femoral artery as an inflow vessel, and the graft placed in the suprapubic region. We perform this procedure when anatomic reconstruction is not possible or is contraindicated. Objective. To analyze the influence of different risk factors on early patency of femoro-femoral crossover bypass. Methods. This retrospective study analyzed the results of 88 femoro-femoral bypass grafting during an 11-year period. There were 66 (75% males and 22 (25% females of average age 64.93 years (42-79 years. In 76 patients the operations were performed due to critical limb ischemia. Revascularization was urgent in 12 patients, while 76 patients were elective. Dacron prosthesis was used in 81 patients, while PTFE was used in 7 patients. Statistical analysis was made by logistic regression. Results. During hospitalisation the graft remained patent in 82 patients, and graft thrombosis occurred in 6 patients. Limb salvage rate was 90.91%. Early morbidity rate (within the first post-operative month was 13.64%, while early mortality rate was 4.55%. Using logistic regression we established that early graft patency was statistically more significant in males (p<0.05. Age (p=0.07 and hypertension (p=0.08 appeared to be predicting influence of the graft patency on the border of the accepted statistical significance level. Conclusion. Femoro-femoral crossover bypass is a good alternative for revascularization in high risk patients for standard anatomic reconstructions due to comorbid conditions or local problems.

  16. Geschlechtsspezifische Aspekte psychosozialer Variablen bei aortokoronarer Bypass-Operation

    Dunkel, Anne

    2012-01-01

    Following coronary artery bypass graft (CABG) surgery women display not only higher mortality rates, but also report more restrictions in terms of health-related quality of life (HRQoL). So far, the causes for this gender gap could not be fully explained by clinical variables. Therefore, the aim of the present study was to analyze the role of psychosocial variables during recovery following CABG. Six specific problems concerning perioperative gender differences in HRQoL, depression, social su...

  17. Isopentenyl diphosphate (IPP)-bypass mevalonate pathways for isopentenol production.

    Kang, Aram; George, Kevin W; Wang, George; Baidoo, Edward; Keasling, Jay D; Lee, Taek Soon

    2016-03-01

    Branched C5 alcohols are promising biofuels with favorable combustion properties. A mevalonate (MVA)-based isoprenoid biosynthetic pathway for C5 alcohols was constructed in Escherichia coli using genes from several organisms, and the pathway was optimized to achieve over 50% theoretical yield. Although the MVA pathway is energetically less efficient than the native methylerythritol 4-phosphate (MEP) pathway, implementing the MVA pathway in bacterial hosts such as E. coli is advantageous due to its lack of endogenous regulation. The MVA and MEP pathways intersect at isopentenyl diphosphate (IPP), the direct precursor to isoprenoid-derived C5 alcohols and initial precursor to longer chain terpenes, which makes independent regulation of the pathways difficult. In pursuit of the complete "decoupling" of the MVA pathway from native cellular regulation, we designed novel IPP-bypass MVA pathways for C5 alcohol production by utilizing promiscuous activities of two enzymes, phosphomevalonate decarboxylase (PMD) and an E. coli-endogenous phosphatase (AphA). These bypass pathways have reduced energetic requirements, are further decoupled from intrinsic regulation, and are free from IPP-related toxicity. In addition to these benefits, we demonstrate that reduced aeration rate has less impact on the bypass pathway than the original MVA pathway. Finally, we showed that performance of the bypass pathway was primarily determined by the activity of PMD. We designed PMD mutants with improved activity and demonstrated titer increases in the mutant strains. These modified pathways would be a good platform for industrial production of isopentenol and related chemicals such as isoprene. PMID:26708516

  18. Simulation and Analysis of the bypass Influences on Tire Noise

    Haichao Zhou; Guolin Wang; Jian Yang; Shizhou Ying

    2014-01-01

    It is a well-known scientific fact that circumferential groove exists great influence on tire noise. Increasing the void can help the rubber blocks to penetrate faster into the underlying water film and improve anti-skid performance, but which gives way to an increased air pumping noise. Therefore, the structure parameters of circumferential grooves play large influence on tire performance. The goal of this present study is using the bypass to change the grooves design and analysis the influe...

  19. Efficacy of Intravenous Acetaminophen after Coronary Artery Bypass Graft Surgery

    Leick AM; Ratliff PD; Shely RN; Lester WC; Short MR

    2015-01-01

    In recent years, a multimodal approach to post-operative pain control consisting of opioid and non-opioid agents administered simultaneously has been used to provide synergistic effects and reduce opioid-related adverse effects. This is a retrospective, cohort study involving coronary artery bypass graft surgery patients who received scheduled intravenous IV acetaminophen 1gm every 6 hours for 4 doses starting at surgery end time with opioids administered as needed versus opioids as monother...

  20. Early chest tube removal after coronary artery bypass graft surgery

    Mohsen Mirmohammad-Sadeghi

    2009-01-01

    Full Text Available Background: There is no clear data about the optimum time for chest tube removal after coronary artery bypass surgery. Aim: The aim of this study was to assess the impact of the chest tube removal time following coronary artery bypass grafting surgery on the clinical outcome of the patients. Material and Methods: An analysis of data from 307 patients was performed. The patients were randomized into two groups: in group 1 (N=107 chest tubes were removed within the first 24 hours after surgery, whereas in group 2 (N=200, chest tubes were removed in the second 24 hours after surgery. Demographics, lactate and pH at the beginning, during and after the operation, creatinine, left ventricular ejection fraction, inotropic drugs administration, length of ICU stay, and mortality data were collected. Respiratory rate and pain level was assessed. Results: In these surgeries, the mean± standard deviation for the aortic clamping time was 49.18±17.59 minutes and cardiopulmonary bypass time was 78.39±25.12 minutes. The amount of heparin consumed by the second group was higher (P <0.001 which could be considered as an important factor in increasing the drainage time after the surgery (P =0.047. The pain level evaluated 24 hours post-operation was lower in the first group, and the difference in the pain level between the 2 groups evaluated 30 hours post-operation was significant (P=0.016. The mean time of intensive care unit stay was longer in the second group but it was not statistically significant. Conclusion: Early extracting of chest tubes after coronary artery bypass graft surgery when there is no significant drainage can lead to pain reduction and consuming oxygen is an effective measure after surgery toward healing; it doesn′t increase the risk of creation of plural effusion and pericardial effusion.

  1. Assessing Patient bypass Behavior Using Taxi Trip Origin–Destination (OD Data

    Gege Yang

    2016-09-01

    Full Text Available Many patients prefer to use the best hospitals even if there are one or more other hospitals closer to their homes; this behavior is called “hospital bypass behavior”. Because this behavior can be problematic in urban areas, it is important that it be reduced. In this paper, the taxi GPS data of Beijing and Suzhou were used to measure hospital bypass behavior. The “bypass behavior index” (BBI represents the bypass behavior for each hospital. The results indicated that the mean hospital bypass trip distance value ranges from 5.988 km to 9.754 km in Beijing and from 4.168 km to 10.283 km in Suzhou. In general, the bypass shares of both areas show a gradually increasing trend. The following hospitals exhibited significant patient bypass behavior: the 301 Hospital, Beijing Children’s Hospital, the Second Affiliated Hospital of Soochow University and the Suzhou Hospital of Traditional Chinese Medicine. The hospitals’ reputation, transport accessibility and spatial distribution were found to be the main factors affecting patient bypass behavior. Although the hospital bypass phenomena generally appeared to be more pronounced in Beijing, the bypass trip distances between hospitals were found to be more significant in Suzhou.

  2. Modulation method of scroll compressor based on suction gas bypass

    The air conditioners and heat pumps tend to work in much mild environments and part load situations rather than provide the rated full capacity under severe rated testing conditions. Both the capacity and inner compression ratio of the compressor should be regulated according to the working condition for higher energy efficiency and occupants’ comfort. A potential modulating technology of the scroll compressor, suction gas bypass, is investigated in this paper. The principle and operation method are illuminated and the adaptability is validated by experiments and simulations. As a conclusion, an appropriate suction gas bypass can reduce the inner compression loss of the scroll compressor under over compression conditions, enhance the system COP and also largely decrease the heating/cooling capacity of the refrigeration/heat pump system. - Highlights: ► Suction gas bypass (SGB) is an effective regulating method of scroll compressor. ► SGB reduces the inner compression loss under over compression conditions. ► SGB largely decreases the heating/cooling capacity of the refrigeration system.

  3. Ileal loop interposition:an alternative biliar y bypass technique

    Felipe JF Coimbra; Alessandro L Diniz; Heber SC Ribeiro; Wilson L Costa Jr.; Eduardo NP Lima; André L Montagnini

    2010-01-01

    BACKGROUND: Obstructive jaundice is a common condition in advanced digestive cancer. Palliative procedures can improve quality of life and allow patients to attempt a systemic treatment. Bilioenteric anastomosis is still the procedure of choice for patients in many centers. When a surgical bypass is not possible, biliary drainage can be done by placing endoscopic or transparietal stents, which are less durable methods even when an expandable stent is employed. METHODS: A 47-year-old male with an excellent clinical status and a previous cholecystectomy and an exploratory laparotomy for advanced gastric cancer was referred with obstructive jaundice. A preoperative CT scan showed a dilated bile duct and a small mass at the distal hepatic hilum. No other signs of metastasis were found. A surgical bilioenteric anastomosis was indicated. At surgery, a distal choledochal obstruction and a mesenteric retraction by a lymph node mass prevented the jejunum to ascend for a bilioenteric anastomosis. Surgically, an alternative bilioenteric bypass was performed by means of an ileal loop interposition between the bile duct and the jejunum. RESULT: The recovery of the patient was uneventful and his bilirubin levels normalized after one week. The patient was then referred for systemic chemotherapy. CONCLUSIONS: This alternative biliary bypass can be safely and easily performed, and may be a good alternative for patients already referred for surgery because of a better life expectancy and when the jejunum is not an alternative.

  4. Laparoscopic gastric bypass to robotic gastric bypass: time and cost commitment involved in training and transitioning an academic surgical practice.

    Lyn-Sue, Jerome R; Winder, Josh S; Kotch, Shannon; Colello, Jacob; Docimo, Salvatore

    2016-06-01

    The Roux-en-Y gastric bypass is the gold standard procedure for weight loss. This relatively complex procedure has excellent outcomes when performed via laparoscopy. The advent of the DaVinci robotic platform has been a technological advancement. Our goal is to provide information regarding the cost, time commitment, and advantages of transitioning an LRYGB program to an RRYGB program in an academic setting. We retrospectively reviewed the last 25 laparoscopic gastric bypass procedures and the first 25 robotic gastric bypass procedures performed by a single surgeon. We compared clinical outcomes and focused on time and hospital cost during this transition phase. There was no significant demographic difference between the groups. The mean age was 41.7 (RRYGB) years vs 43.4 (LRYGM) years. The mean BMI were similar between groups, 45.3 vs 46.5 kg/m(2) for RRYGB and LRYGB. No anastomotic leaks or mortalities were noted. There was one anastomotic stricture in both groups. Excess weight loss was similar in both groups at 1 year. There was a significant increase in operative time with RRYGB, mean 241 min vs mean 174 min (p = 0.0005). Operative time fell by 25 min after the first 10 cases. The hospital cost was also increased with RRYGB mean $5922 vs $4395 (p = 0.03). Transitioning from a laparoscopic to a robotic practice can be done safely, however, the initial operative times were longer and the hospital cost was higher for robotic gastric bypass. We hope in the future that these will decrease after overcoming the learning and as the technology becomes widespread. PMID:26983848

  5. Passage of downstream migrant American eels through an airlift-assisted deep bypass

    Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

    2016-01-01

    Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not

  6. Perioperative risk factors for prolonged mechanical ventilation and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass

    Zahra S Faritous

    2011-01-01

    Full Text Available Background: Prolonged mechanical ventilation is an important recognized complication occurring during cardiovascular surgery procedures. This study was done to assess the perioperative risk factors related to postoperative pulmonary complications and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass. Methods: It was a retrospective study on 5,497 patients, including 31 patients with prolonged ventilatory support and 5,466 patients without it; from the latter group, 350 patients with normal condition (extubated in 6-8 hours without any complication were selected randomly. Possible perioperative risk factors were compared between the two groups using a binary logistic regression model. Results: Among the 5,497 women undergoing coronary artery bypass graft (CABG, 31 women needed prolonged mechanical ventilation (PMV, and 15 underwent tracheostomy. After logistic regression, 7 factors were determined as being independent perioperative risk factors for PMV. Discussion: Age ≥70 years old, left ventricular ejection fraction (LVEF ≤30%, preexisting respiratory or renal disease, emergency or re-do operation and use of preoperative inotropic agents are the main risk factors determined in this study on women undergoing CABG.

  7. Effects of topical hypothermia on postoperative inflammatory markers in patients undergoing coronary artery bypass surgery

    Kadan, Murat; Erol, Gokhan; Savas Oz, Bilgehan; Arslan, Mehmet

    2014-01-01

    Summary Background We aimed to examine the effects of topical hypothermia on inflammatory markers in patients undergoing coronary artery bypass surgery. Methods Fifty patients undergoing isolated coronary artery bypass surgery were included the study. They were randomised to two groups. Mild hypothermic cardiopulmonary bypass (28–32°C) was performed on both groups using standardised anaesthesiology and surgical techniques. Furthermore, topical cooling with 4°C saline was performed on patients...

  8. Why caretakers bypass Primary Health Care facilities for child care - a case from rural Tanzania

    Kahabuka Catherine; Kvåle Gunnar; Moland Karen; Hinderaker Sven

    2011-01-01

    Abstract Background Research on health care utilization in low income countries suggests that patients frequently bypass PHC facilities in favour of higher-level hospitals - despite substantial additional time and financial costs. There are limited number of studies focusing on user's experiences at such facilities and reasons for bypassing them. This study aimed to identify factors associated with bypassing PHC facilities among caretakers seeking care for their underfive children and to expl...

  9. Effect of Dextrose-Crystalloid Priming Solution on Fluid Requirements and Urine Output During Cardiopulmonary Bypass

    Metz, Samuel; Hacker, Jerriann

    1986-01-01

    We examined the influence of the addition of dextrose to crystalloid cardiopulmonary bypass priming solution. Ten patients received only lactated Ringer's solution during the perioperative period and as their cardiopulmonary bypass priming solution, while ten others, managed identically in all other respects, received only 5% dextrose in lactated Ringer's solution (D 5LR). During cardiopulmonary bypass, patients who did not receive glucose required more supplementary fluid (20.0 vs 2.2 ml Kg−...

  10. Cost Performance and Efficacy of Off-pump Coronary Artery Bypass Grafting

    Nomura, Fumikazu; Mukai, Shogo; Tamura, Kentaro; Shimazutsu, Kazufumi; Okuma, Kazuhide; Ihara, Katsuhiko

    2002-01-01

    Off-pump coronary artery bypass grafting (Off-Pump CABG) may provide an alternative form of surgical revascularization by avoiding the unwanted complications of cardiopulmonary bypass, particularly in high-risk patients. To clarify the efficacy and cost performance of Off- Pump CABG, we studied the postoperative course of Off-Pump CABG and compared it to On- pump coronary artery bypass grafting (On-Pump CABG). From Aug. 1998 to Feb. 2002, twenty-eight patients who had preoperative complicatio...

  11. Multiple Rad5 activities mediate sister chromatid recombination to bypass DNA damage at stalled replication forks

    Minca, Eugen C; Kowalski, David

    2010-01-01

    DNA damage that blocks replication is bypassed in order to complete chromosome duplication and preserve cell viability and genome stability. Rad5, a PCNA polyubiquitin ligase and DNA-dependent ATPase in yeast, is orthologous to putative tumor suppressors and controls error-free damage bypass by an unknown mechanism. To identify the mechanism in vivo, we investigated the roles of Rad5 and analyzed the DNA structures that form during damage bypass at site-specific stalled forks present at repli...

  12. Comparative study of the protective effect using hypothermic cardiopulmonary bypass and normothermic cardiopulmonary bypass

    HAN Pei-li; FU Qing-lin; ZHANG Xin-zhong; ZHANG-Jie; QIN Yuan-xu; CUI Yu

    2007-01-01

    Objective To explore the detrimental influence of normothermic and hypothermic cardiopulmonary by-pass during open - heart surgery on immunity function,cytokines and complements. Methods Forty patients with con-genital or rheumatic heart disease were randomized to receive the two strategies: normothermie CPB (study group) andhypothermic CPB (control group) ,20 cases in each group. Venous blood samples were collected at each time points ofpreoperation, end of CPB, day 1,4,7,14 postoperatively to examine the plasma level of IL - 2, TNF - α, C3, C4, IgG,IgM, IgA, CD3, CD4, CD8. Results IL -2 in both groups decreased significantly at day 1,4, and returned to normal atday 7 postoperatively. IL - 2 in control group was significantly lower than that in study group postoperatively. TNF - α intwo groups was all higher at time points of end of CPB,day 1,4 postoperatively;in study group,it returned to normallevel at day 7 postoperatively, whereas in control group, it was still higher at day 7 postoperatively than that before oper-ation ,and returned to normal at day 14 postoperatively. C3 in study group was significantly lower at time points of endof CPB,day 1,7 postoperatively than that in control group;C3 in both groups was all higher at time points of end ofCPB, day 1,4 postoperatively;in study group, it returned to normal level at day 7 postoperatively, whereas in controlgroup,it was still higher at day 7 postoperatively than that before operation and returned to normal at day 14 postopera-tively. CA in study group at time points of end of CPB, day 1 postoperatively was significantly lower than that in controlgroup;C4 in both groups was all lower at time points of end of CPB, day 1,4 postoperatively than that before operation.The results showed that IgA after operation in both groups was significantly lower than that before operation, and re-turned to normal at day 7 postoperatively;IgA in study group at day 1 postoperatively was higher than that in controlgroup. IgG in

  13. Perioperative considerations in a sickle cell patient undergoing cardiopulmonary bypass

    Monish S Raut

    2014-01-01

    Full Text Available An 11-year-old child, a known case of sickle cell anaemia with a history suggestive of sickling crisis in the past was scheduled for surgical pulmonary valvotomy. Pre-operative blood transfusion and hydroxyurea were administered. Pre-operative blood transfusion is indicated in sickle cell disease patients to raise the haematocrit level and lower sickle haemoglobin (HbS levels. Before the start of cardiopulmonary bypass (CPB, exchange transfusion was performed to reduce HbS level and raise adult haemoglobin level. Hypothermia was prevented by employing normothermic CPB.

  14. Incidental invasive thymoma during coronary artery bypass surgery.

    Al-Smady, Moaath; Hammdan, Farouq F; Abu-Abeeleh, Mahmood M; Massad, Islam M

    2009-01-01

    We encountered 2 incidental cases of invasive thymomas at Jordan University Hospital, Amman, Jordan; during routine coronary artery bypass graft surgery between 2005 and 2008 with an incidence of 0.6%. Both patients presented with angina pain. None of the 2 patients had pressure symptoms (cough, shortness of breath or superior vena cava syndrome) or Myasthenia Gravis symptoms. Total thymectomy with dissection of perithymic fat was performed on both cases. No radiotherapy was given. No recurrence of the tumor was seen in 2 years follow up. These cases are presented to emphasize the occurrence of this tumor. PMID:19139788

  15. Bypass Pigging of Subsea Pipelines Suffering Wax Deposition

    Galta, Tore

    2014-01-01

    Which criteria to pay attention to is important when finding the optimal pigging frequency. This thesis illustrates the forces acting on a bypass pig in operation. Expressions for both the frictional force and wax removal force have been presented. Results presented in this thesis show that the frictional forces are much higher than the forces for wax removal. The most important factor for the contact forces for a cleaning pig seems to be due to the oversize of the discs. However, it is diffi...

  16. Fatal Pyoderma Gangrenosum with Pathergy after Coronary Artery Bypass Grafting

    Bryan, Charles S.

    2012-01-01

    Surgeons and others who perform invasive procedures should be aware of the possibility of pyoderma gangrenosum and the risk of pathergy in patients who have a history of unexplained skin ulcers or poor wound-healing. We report the case of a 70-year-old man in whom diffuse erythema over the anterior chest wall and marked leukocytosis developed after coronary artery bypass grafting. This prompted débridement and opening of the sternotomy wound. The cause of the erythema was pyoderma gangrenosum...

  17. Deoxypyrimidine monophosphate bypass therapy for thymidine kinase 2 deficiency

    Garone, Caterina; Garc??a-D??az, Beatriz; Emmanuele, Valentina; L??pez Garc??a, Luis Carlos; Tadesse, Saba; Akman, Hasan O.; Tanji, Kurenai; Quinzii, Catarina M.; Hirano, Michio

    2014-01-01

    Autosomal recessive mutations in the thymidine kinase 2 gene (TK2) cause mitochondrial DNA depletion, multiple deletions, or both due to loss of TK2 enzyme activity and ensuing unbalanced deoxynucleotide triphosphate (dNTP) pools. To bypass Tk2 deficiency, we administered deoxycytidine and deoxythymidine monophosphates (dCMP+dTMP) to the Tk2 H126N (Tk2 −/− ) knock-in mouse model from postnatal day 4, when mutant mice are phenotypically normal, but biochemically affected. Assessment of 13-day-...

  18. [Dealing with surgical complications after bariatric gastric bypass surgery].

    Schlesinger, Nis Hallundbæk; Naver, Lars

    2013-11-25

    The subject of this article is surgical complications to Roux-en-Y-gastric bypass and how to deal with them. The article addresses doctors, who are on duty in hospitals without bariatric surgery and who often deal with this patient category in the acute situation. Managing complications is challenging due to both the patient's physiognomy and the wide-ranged change in anatomy. The article gives a review of the literature and hands-on-recommendations for treating anastomotic leak, post-operative bleeding, internal herniation, bowel obstruction and biliary complications. PMID:24629437

  19. Lepirudin as an alternative to "heparin allergy" during cardiopulmonary bypass

    Parissis Haralabos

    2011-04-01

    Full Text Available Abstract A treatment strategy of a difficult and unusual problem is presented. We are reporting a case of a patient who had a documented allergy to heparin and required Cardiac surgery for an ASD closure. The anticoagulation regime used during cardiopulmonary bypass was lepirudin based. This report indicates that r-hirudin provides effective anticoagulation, however unless ECT is monitoring, post operative hemorrhage is encountered. Therefore this case is unique not only because of its rarity but also by the fact that it presents the caveats encountered when ECT is not available.

  20. Flow quantification of the non-occlusive excimer laser-assisted EC-IC bypass

    Background. For six years, we used the excimer laser-assisted non-occlusive anastomosis technique for high-flow revascularization of the brain in patients with either nonclippable and noncoilable giant aneurysms of the internal carotid or basilar artery or progressive stroke associated with occlusive disease of the internal carotid artery. The aim of this study is to assess the blood flow capacity of this type of extra-intracranial bypass and its haemodynamic behavior over time. Methods. Twenty-six patients with a giant aneurysms and 8 patients with occlusive disease of the internal carotid artery were treated with the non-occlusive excimer laser assisted EC-IC bypass. Intra-operatively, direct measurements of flow in the EC-IC bypass were performed in all patients (Transonic Systems, Inc., Ithaca, NY). Postoperatively, follow up measurements of flow were performed with MR angiography in 14 patients with a giant aneurysm after occluding the internal carotid artery, and 7 patients with occlusive carotid disease. Results. The mean flow in the laser assisted bypasses in the group of patients with a giant aneurysm was 158 ml/min after ligation or balloon occlusion of the ICA. The mean flow of the laser assisted bypass in the group of patients with ICA occlusive disease was 130 ml/min. A comparison with data on flow capacity of conventional EC IC bypasses is made. A demonstrated increase of flow in the bypass during follow up is discussed from a haemodynamic point of view. Conclusions. The results of this study demonstrate that the flow capacity of the non-occluding excimer laser assisted bypass is much higher than the capacity of the conventional, more peripherally located conventional EC IC bypass, and should therefore be denoted as high-flow EC IC bypass. Consequently, this type of bypass can be a powerful and safe tool in new revascularization strategies. (author)

  1. Heparin Therapy during Extracorporeal Circulation: Deriving an Optimal Activated Clotting Time during Cardiopulmonary Bypass for Isolated Coronary Artery Bypass Grafting

    Palmer, Kenneth; Ridgway, Tim; Al-Rawi, Omar; Poullis, Michael

    2012-01-01

    Bull’s seminal work on heparin therapy during cardiopulmonary bypass (CPB) was carried out over 30 years ago and has not been updated in the modern era. No correlation with postoperative blood loss was performed. The optimal activated clotting time (ACT) with regard to blood loss has not been established for patients undergoing CPB. A minimum ACT of 400 is based on the lack of visible formation of clots in the CPB circuit. The effect of heparin dose, sensitivity, metabolism, patient size, ele...

  2. Nursing care for the patient after femoral popliteal bypass grafting

    Guo Xiaohui

    2003-01-01

    Objective: To share my knowledge, regarding the nursing care for the patients after femoral popliteal bypass grafting, with my Chinese colleagues who have never been abroad. Methods: From August 1998 to September 2002, five patients (including 1 female and 4 male) were summarized retrospectively on postoperative care by assessment, nursing implementation and evaluation. Results: All patients were followed up for 3 to 6 months. The results were evaluated as follows: patient's condition and the function of the operated leg were improved. The leg pain was released. The peripheral pulses were present and strong. The color, temperature and sensation of the skin were normal. None of further complications was noted. Conclusion: For Nursing the patient after femoral popliteal bypass grafting, the nurses should focus their attention on the circulatory status of the operated leg, anticoagulant therapy and signs of bleeding from the graft site. Meanwhile, provide a quiet、comfortable and safety environment for the patient. Asall of these are the main points of the postoperative care. A good nursing careoffer to a patient not only can ease the patient's physical suffering, but alsocan avoid some complications occurring.

  3. CLINICAL ADVANTAGES OF TOTAL CAVOPULMONARY ANASTOMOSIS WITHOUT CARDIOPULMONARY BYPASS

    Jun-min Chu; Qing-yu Wu; Jian-ping Xu

    2005-01-01

    Objective To evaluate surgical methods and results of extracardiac conduit total cavopulmonary anastomosis (ECTCPA) without cardiopulmonary bypass (CPB).Methods From May 2000 to April 2003, 11 patients with functional univentricle underwent off-pump EC-TCPA (noCPB group). Their postoperative outcome was retrospectively compared with a 17-patient group who underwent EC-TCPA with cardiopulmonary bypass (CPB group) over a concurrent time period.Results There was 1 operative death in no-CPB group and 2 in CPB group; early postoperative hemodynamics appeared to significantly improve in no-CPB group. Blood and platelet transfusions decreased and blood plasma transfusion significantly lowered in no-CPB group compared with CPB group (P = 0.036). Postoperative courses of patients in no-CPB group were smooth and event free, and extubation time was substantially short. Intensive cares unit stay (P=0.04) and hospital stay (P= 0.02) postoperation were significantly shorter, hospital costs were significantly reduced (P= 0.004) in no-CPB group compared with CPB group.Conclusions EC-TCPA without use of CPB is not a difficult procedure; the procedure results in improvement in postoperative hemodynamics, and decreased use of blood and blood products. It is a more efficient operation with more short recovery time and reduced hospital stay.

  4. Bypass transition of the bottom boundary layer under solitary wave

    Sadek, Mahmoud; Diamessis, Peter; Parras, Luis; Liu, Philip

    2015-11-01

    The transition to turbulence in the bottom boundary layer (BBL) flow driven by a soliton-like pressure gradient in an oscillating water tunnel (an approximation for the BBL under solitary waves) is investigated using hydrodynamic linear stability theory and DNS. As observed in the laboratory experiment by Sumer et al. (2010), two possible transition scenarios exist. The first scenario is associated with the classical transition resulting from the breakdown of the exponentially growing 2-D Tollmien-Schlichting waves. The alternative scenario; i.e., bypass transition; takes place through formation of localized turbulent spots. The investigation of the latter transition scenario is performed in two steps. The first step consists of reformulating the linear stability analysis in the non-modal framework for the purpose of finding the optimum disturbance characteristics which lead to the formation of those turbulent spots. In the second step, the computed optimum noise structure is inserted in the 3D DNS in order to induce the formation of the turbulent spots and effectively simulate the bypass transition observed experimentally.

  5. Do Statins Reduce Atrial Fibrillation After Coronary Artery Bypass Grafting?

    Anil Paturi MD

    2011-07-01

    Full Text Available Background Atrial Fibrillation (AF is a common postoperative complication after coronary artery bypass grafting. There is contradictory evidence as to whether pre-operative statin use lowers the incidence of postoperative AF. This study aimed to assess whether pre operative statin therapy prevents the post-operative AF. Methods In this retrospective cohort study we used a propensity score–matching analysis to evaluate the effect of preoperative treatment with statins on postoperative atrial fibrillation. There were 427 matched pairs of patients. Primary outcome was the incidence of postoperative AF. Secondary outcomes were 30 day mortality, stroke, myocardial infarction and length of hospital stay Results The incidence of postoperative AF was not different in the statin users compared with the nonusers (123, 28.1%, versus 127, 29.7%, respectively; p = 0.764. The 30 day mortality (6, 1.4%, versus 8, 1.9%; p = 0.590, stroke (10, 2.3%, versus 8, 1.9%; p = 0.634, myocardial infarction (2, 0.5%, versus 0, 0.0%; p = 0.499 and length of hospital stay in days (11.8 ± 9.0, versus 11.9 ± 9.3; p = 0.544 did not differ significantly between the two groups. Conclusions In a propensity-matched cohort of patients undergoing coronary bypass surgery, we could not demonstrate that preoperative statins were protective for the development of post operative atrial fibrillation.

  6. Diabetes severely affects attentional performance after coronary artery bypass grafting

    Krannich Jens-Holger

    2012-11-01

    Full Text Available Abstract Background Diabetes is a risk factor for (micro vascular damage of the brain, too. Therefore cognitive performance after coronary artery bypass grafting may be hypothesized worse in diabetics. To avoid observational errors a reliable tool for testing attentional performance was used. We evaluated whether diabetes mellitus disposes to distinct cognitive dysfunction after coronary artery bypass grafting (CABG. Methods Three aspects in attentional performance were prospectively tested with three different tests (alertness: composed of un-cued and cued reaction, divided attention, and selective attention by a computerized tool one day before and seven days after CABG in a highly selected cohort of 30 males, 10 of whom had diabetes. Statistical comparisons were done with analysis of variance for repeated measurements and Fisher's LSD. Results Prior to CABG there was no statistically meaningful difference between diabetics and non-diabetics. Postoperatively, diabetic patients performed significantly worse than non-diabetics in tests for un-cued (p=0.01 and cued alertness (p=0.03. Test performance in divided attention was worse after CABG but independent of diabetes status. Selective attention was neither affected by diabetes status nor by CABG itself. Conclusions Diabetes may have an impact on cognitive performance after CABG. More severe deficits in alertness may point to underlying microvascular disease.

  7. Implementation of magnetohydrodynamic energy bypass process for hypersonic vehicles

    Lee, Ying Ming; Czysz, Paul A.; Bruno, Claudio

    2004-08-01

    The global political structure has changed dramatically since the breakup of the former Soviet Union, and world changes have caused the United States to reprioritize its national hypersonic needs. The US Government has looked at the needs of the future, and the hypersonic aerospace plane is one of the systems included in alternative force structures. One hypersonic aerospace plane concept would involve magnetohydrodynamic (MHD) technology (i.e., the AJAX hypersonic flight vehicle concept) originally proposed by Russian scientist Vladimir Fraishtadt. This paper reports on the current progress and findings of an air-breathing horizontal takeoff and landing design concept using an MHD energy bypass injector ramjet engine being studied at MSE Technology Applications, Inc., HyperTech Concepts, and several universities for the National Aeronautics and Space Administration Langley Research Center under a Phase II Small Business Innovation Research project. The areas that are addressed in this paper include: (1) ionization required to achieve the required energy bypass, (2) utilization of a nonequilibrium model to calculate nonequilibrium engine ionization conditions, (3) hydrocarbon fuel reforming, and (4) vehicle performance and sizing. A quasi-onedimensional electromagnetic code combined with a new scramjet model, as well as other tools, were used to examine total system performance.

  8. Myocardial contractile function in survived neonatal piglets after cardiopulmonary bypass

    Popov Aron-Frederik

    2010-11-01

    Full Text Available Abstract Background Hemodynamic function may be depressed in the early postoperative stages after cardiac surgery. The aim of this study was the analysis of the myocardial contractility in neonates after cardiopulmonary bypass (CPB and mild hypothermia. Methods Three indices of left ventricular myocardial contractile function (dP/dt, (dP/dt/P, and wall thickening were studied up to 6 hours after CPB in neonatal piglets (CPB group; n = 4. The contractility data were analysed and then compared to the data of newborn piglets who also underwent median thoracotomy and instrumentation for the same time intervals but without CPB (non-CPB group; n = 3. Results Left ventricular dP/dtmax and (dP/dtmax/P remained stable in CPB group, while dP/dtmax decreased in non-CPB group 5 hours postoperatively (1761 ± 205 mmHg/s at baseline vs. 1170 ± 205 mmHg/s after 5 h; p max and (dP/dtmax/P there were no statistically significant differences between the two groups. Comparably, although myocardial thickening decreased in the non-CPB group the differences between the two groups were not statistically significant. Conclusions The myocardial contractile function in survived neonatal piglets remained stable 6 hours after cardiopulmonary bypass and mild hypothermia probably due to regional hypercontractility.

  9. A bypass transition in the Lamb-Oseen vortex

    Bisanti, Luigi; Brancher, Pierre; Airiau, Christophe

    2012-11-01

    Transient energy growth in the short-time linear dynamics of a Lamb-Oseen monopole is a potential mechanism for nonlinear bypass transition, a phenomenon already observed in both experiments and numerical simulations. In the present study, we investigate this scenario by means of a nonlinear optimal perturbation approach, i.e. by looking for the initial perturbation whose evolution satisfies the fully nonlinear Navier-Stokes equations and maximizes the energy gain at a given time horizon. Preliminary two-dimensional results show that, for small initial amplitudes, the optimal perturbation and growth mechanisms observed in the linear regime are recovered. More particularly, the time evolution of the m = 2 optimal perturbation leads to an elliptical core deformation of the monopole, which suggests a potential bypass scenario driven by the non-linear dynamics. This is confirmed by computations for larger initial perturbation amplitudes: the optimal perturbation is similar to that of the linear regime but a subcritical bifurcation to a quasi-steady, high-energy, rotating tripole is observed.

  10. Anesthesia for off-pump coronary artery bypass surgery

    Thomas M Hemmerling

    2013-01-01

    Full Text Available The evolution of techniques and knowledge of beating heart surgery has led anesthesia toward the development of new procedures and innovations to promote patient safety and ensure high standards of care. Off-pump coronary artery bypass (OPCAB surgery has shown to have some advantages compared to on-pump cardiac surgery, particularly the reduction of postoperative complications including systemic inflammation, myocardial injury, and cerebral injury. Minimally invasive surgery for single vessel OPCAB through a limited thoracotomy incision can offer the advantage of further reduction of complications. The anesthesiologist has to deal with different issues, including hemodynamic instability and myocardial ischemia during aorto-coronary bypass grafting. The anesthesiologist and surgeon should collaborate and plan the best perioperative strategy to provide optimal care and ensure a rapid and complete recovery. The use of high thoracic epidural analgesia and fast-track anesthesia offers particular benefits in beating heart surgery. The excellent analgesia, the ability to reduce myocardial oxygen consumption, and the good hemodynamic stability make high thoracic epidural analgesia an interesting technique. New scenarios are entering in cardiac anesthesia: ultra-fast-track anesthesia with extubation in the operating room and awake surgery tend to be less invasive, but can only be performed on selected patients.

  11. Feed technology and other methods for increasing the bypass protein for ruminants fed low quality forages

    To make use of crop residues, the protein and energy needs of the ruminant must be met. Inexpensive sources of rumen ammonia (urea or ammonia from ammoniation) cam meet the needs of the rumen microorganisms. The cost of protein supplementation can be reduced by using sources of high bypass protein with the sources of ammonia. Accurate evaluation of protein is necessary. Estimates of the bypass values for protein sources can be made from laboratory analyses or by directly measuring the bypass of a protein source with intestinally fistulated animals. These values are useful as supporting evidence; however, measurement of animal growth or production is the best way to obtain these bypass values. It is essential that proteins be compared below the animal's protein requirement. Otherwise, protein is not the first limiting nutrient and valid comparisons cannot be made. The protein in grain, especially corn and milo, is bypassed to a great extent and, therefore, the grain by-products are high in bypass protein. Heating reduces rumen degradation of proteins and, therefore, the drying of dehydrated alfalfa, blood meal and meat meal causes them to be high bypass protein sources. Hydrolysed feather meal and non-enzymatically browned protein are also good sources of bypass protein. (author). 15 refs, 7 figs, 2 tabs

  12. Fluoropolymer-coated dacron versus PTFE grafts for femorofemoral crossover bypass: randomised trial

    Eiberg, J P; Røder, Ole Christian; Stahl-Madsen, Morten; Eldrup, Nikolaj; Qvarfordt, Peter; Laursen, Anders; Greve, Max; Flörenes, Tor; Nielsen, O M; Seidelin, Claus; Vestergaard-Andersen, Torben; Schroeder, T V

    2006-01-01

    To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery.......To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery....

  13. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    2010-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange...

  14. Antique SVG with two humps: a case of two giant aneurysms of single saphenous vein bypass graft.

    Kurita, Tairo; Kitamura, Tetsuya; Yamanaka, Takashi; Tanabe, Masaki; Dohi, Kaoru; Tanigawa, Takashi; Onishi, Katsuya; Ito, Masaaki; Isaka, Naoki; Nakano, Takeshi

    2007-03-20

    Saphenous vein graft aneurysms are a rare complication of coronary artery bypass surgery. In this article, we present a 3-dimensional computed tomography image of two giant aneurysms of a single saphenous vein bypass graft. PMID:17070939

  15. The effect of cardiopulmonary bypass in coronary artery bypass surgeries (on-pump versus off-pump) on erectile function and endothelium-derived nitric oxide levels

    Onder Canguven; Selami Albayrak; Ahmet Selimoglu; Muhsin Balaban; Ahmet Sasmazel; Ayse Baysal

    2011-01-01

    PURPOSE: To investigate the effects of on-pump and off-pump coronary artery bypass grafting (CABG) on the erectile function and endothelium-derived nitric oxide (eNO) levels. MATERIALS AND METHODS: Twenty-eight consecutive patients were randomized into two groups depending on use of cardiopulmonary bypass in CABG surgery. The erectile function was evaluated by using the IIEF-5 questionnaire. The plasma eNO levels were determined at baseline and after reactive hyperemia before and after surger...

  16. Does transfusion of residual cardiopulmonary bypass circuit blood increase postoperative bleeding? A prospective randomized study in patients undergoing on pump cardiopulmonary bypass

    Duara Rajnish; Misra Manoranjan; Bhuyan Ritwick; Sarma P; Jayakumar Karunakaran

    2008-01-01

    Objective: Homologous blood transfusion after open heart surgery puts a tremendous load on the blood banks. This prospective randomized study evaluates the efficacy of infusing back residual cardiopulmonary bypass (CPB) circuit i.e., pump blood as a means to reduce homologous transfusion after coronary artery bypass surgery (CABG) and whether its use increases postoperative drainage. Materials and Methods: Sixty-seven consecutive patients who underwent elective CABGs under CPB were randomi...

  17. Obturator or "lateral" bypass in the management of infected vascular prostheses at the groin

    Davidović Lazar B.

    2002-01-01

    Full Text Available The infection of the previously implanted vascular graft at the groin, is associated with great mortality and morbidity rate [1]. The authors present a retrospective study in which they analyzed management of infected vascular prostheses at the groin, using obturator bypass in 26 cases, and "lateral" bypass in 15 cases. The indications for obturator bypass reconstructions included: 20 infections of aorto-femoral grafts, two infected pse udoaneurysms in the groin after RTA of the superficial femoral artery, and 4 infections of iliac-femoral grafts. The indications for lateral bypass reconstructions were: infections after aorto-femoral reconstructions - 8 cases; infection after femora-popliteal reconstructions - 4 cases; infection after iliac-femoral reconstruction - 2 patients, and one infected pseudoaneurysm in the groin after RTA of the superficial femoral artery. In 3 subjects obturator bypass was performed using extraperitoneal approach while in other 23 patients transperitoneal approach was done by donor's artery. The obturator bypass was performed using a PTFE graft in 3 cases and Dacron graft in 23. The donor's artery used for obturator bypass was a noninfected proximal part of aortofemoral graft in 20 cases, and iliac artery in 6 patients. The superfical femoral artery was recipient artery for obturator bypass in 3 cases, deep femoral artery in one case, and above the knee popliteal artery in 22 cases (Figure 1. In two patients transperitoenal approach to donors artery for "lateral" bypass has been used, and in 13 cases extraperitoneal. The proximal noninfected part of aorto femoral graft was used as a donor's artery for lateral bypass in 8 patients, while common iliac artery in 7 subjects. In 5 cases recon structions were performed using PTFE grafts, in 3 using autologous saphenous vein grafts, and in 7 using Dacron grafts. The recipient artery for "lateral" bypass was deep femoral in 8 cases, superficial femoral in three patients and

  18. Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms: options, technical challenges, and results in 35 patients.

    Abla, Adib A; McDougall, Cameron M; Breshears, Jonathan D; Lawton, Michael T

    2016-05-01

    OBJECT Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (EC-IC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed. METHODS Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA's origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included. RESULTS During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 IC-IC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients. CONCLUSIONS PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one

  19. Numerical and experimental investigation on labyrinth seal mechanism for bypass flow reduction in prismatic VHTR core

    Yoon, Su-Jong, E-mail: paper80@snu.ac.r [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Lee, Jeong-Hun [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Lee, Sang-Moon [Department of Mechanical Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Incheon 402-751 (Korea, Republic of); Tak, Nam-il; Kim, Min-Hwan [Korea Atomic Energy Research Institute, 150-1 Deokjin-Dong, 1045 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Kwang-Yong [Department of Mechanical Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Incheon 402-751 (Korea, Republic of); Park, Goon-Cherl [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of)

    2013-09-15

    Highlights: • Bypass flow reduction method was developed by applying labyrinth seal mechanism. • Grooves on side walls of replaceable reflector block were made. • Design of the grooved wall of the reflector block was optimized by the RSA method. • The flow resistance of the bypass gap rose from 18.04 to 26.24 by the optimization. • The bypass ratios at the inlet and outlet were reduced by 36.19% and 14.66%, respectively. -- Abstract: Core bypass flow in block type very high temperature reactor (VHTR) occurs due to the inevitable gaps between the hexagonal core blocks for the block installation and refueling. Since the core bypass flow affects the reactor safety and efficiency, it should be minimized to enhance the core thermal margin. In this regard, the core bypass flow reduction method applying the labyrinth seal mechanism was developed and optimized by using the single-objective shape optimization method. Response surface approximation (RSA) method was adopted as the optimization method. Side wall of the replaceable reflector block was redesigned and response surface approximate model was adopted to optimize the shape of the reflector wall. Computational fluid dynamics (CFD) analyses were carried out not only to assess the limitation of existing method of bypass flow reduction, but also to optimize the design of a newly developed reduction method. The experiment with Seoul National University (SNU) multi-block experimental facility was performed to demonstrate the performance of the reduction method. It was found that the effect of the existing bypass flow reduction method by sealing the bypass gap exit was restricted nearby the lower region of the core. However, the flow resistance factor of the bypass gap increased from 18.04 to 26.24 by the optimized reduction method. The results of the performance test showed that the bypass flow distribution was reduced throughout the entire core regions. The bypass flow ratios at the inlet and the outlet were

  20. Numerical and experimental investigation on labyrinth seal mechanism for bypass flow reduction in prismatic VHTR core

    Highlights: • Bypass flow reduction method was developed by applying labyrinth seal mechanism. • Grooves on side walls of replaceable reflector block were made. • Design of the grooved wall of the reflector block was optimized by the RSA method. • The flow resistance of the bypass gap rose from 18.04 to 26.24 by the optimization. • The bypass ratios at the inlet and outlet were reduced by 36.19% and 14.66%, respectively. -- Abstract: Core bypass flow in block type very high temperature reactor (VHTR) occurs due to the inevitable gaps between the hexagonal core blocks for the block installation and refueling. Since the core bypass flow affects the reactor safety and efficiency, it should be minimized to enhance the core thermal margin. In this regard, the core bypass flow reduction method applying the labyrinth seal mechanism was developed and optimized by using the single-objective shape optimization method. Response surface approximation (RSA) method was adopted as the optimization method. Side wall of the replaceable reflector block was redesigned and response surface approximate model was adopted to optimize the shape of the reflector wall. Computational fluid dynamics (CFD) analyses were carried out not only to assess the limitation of existing method of bypass flow reduction, but also to optimize the design of a newly developed reduction method. The experiment with Seoul National University (SNU) multi-block experimental facility was performed to demonstrate the performance of the reduction method. It was found that the effect of the existing bypass flow reduction method by sealing the bypass gap exit was restricted nearby the lower region of the core. However, the flow resistance factor of the bypass gap increased from 18.04 to 26.24 by the optimized reduction method. The results of the performance test showed that the bypass flow distribution was reduced throughout the entire core regions. The bypass flow ratios at the inlet and the outlet were

  1. Photovoltaic power generation system free of bypass diodes

    Lentine, Anthony L.; Okandan, Murat; Nielson, Gregory N.

    2015-07-28

    A photovoltaic power generation system that includes a solar panel that is free of bypass diodes is described herein. The solar panel includes a plurality of photovoltaic sub-modules, wherein at least two of photovoltaic sub-modules in the plurality of photovoltaic sub-modules are electrically connected in parallel. A photovoltaic sub-module includes a plurality of groups of electrically connected photovoltaic cells, wherein at least two of the groups are electrically connected in series. A photovoltaic group includes a plurality of strings of photovoltaic cells, wherein a string of photovoltaic cells comprises a plurality of photovoltaic cells electrically connected in series. The strings of photovoltaic cells are electrically connected in parallel, and the photovoltaic cells are microsystem-enabled photovoltaic cells.

  2. Study of transient turbine shot without bypass in a BWR

    The study and analysis of operational transients are important for predicting the behavior of a system to short-terms events and the impact that would cause this transition. For the nuclear industry these studies are indispensable due to economic, environmental and social impacts that could result in an accident during the operation of a nuclear reactor. In this paper the preparation, simulation and analysis of results of a turbine shot transient, which is not taken into operation the bypass is presented. The study is realized for a BWR of 2027 MWt, to an intermediate cycle life and using the computer code Simulate-3K a depressurization stage of the vessel is created which shows the response of other security systems and gives a coherent prediction to the event presented type. (Author)

  3. Robotic coronary artery bypass for aberrant right coronary artery stenosis.

    Chen, Kuan-chin Jean; Teefy, Patrick; Kiaii, Bob; Vezina, William C; Chu, Michael Wa

    2010-10-01

    Anomalous coronary arteries that course between the aorta and pulmonary artery are subject to compressive forces and can manifest angina, myocardial infarction and sudden death. The current report presents a young, female patient who presented with a short duration of severe, rapidly progressive angina despite optimal medical therapy. Combined computed tomography and myocardial perfusion scanning identified an anomalous dominant right coronary artery that appeared kinked at its origin between the aorta and main pulmonary artery. A robot-assisted right internal thoracic artery to right coronary artery bypass was performed, which was confirmed to be widely patent (FitzGibbon grade A) on routine intraoperative angiography. The procedure completely resolved the patient's angina symptoms. PMID:20931103

  4. In situ saphenous vein bypass surgery in diabetic patients

    Jensen, L P; Schroeder, T V; Lorentzen, J E

    1992-01-01

    or foot. Diabetic patients had a significantly lower distal anastomosis than non-diabetic patients (p = 0.0001). The overall 3-year primary and secondary patency rates were 58 and 64%, respectively, with no differences between non-diabetics, non-insulin-dependent diabetics and insulin......From 1986 through to 1990 a total of 483 consecutive in situ infra-inguinal vein bypass procedures were performed in 444 patients, of whom 112 (25%) were diabetics (57 insulin dependent diabetes mellitus and 55 non-insulin-dependent diabetes mellitus). Based on a prospective vascular data registry...... this material was analysed to determine the influence of diabetes on the outcome. Preoperative risk factors were equally distributed among diabetic and non-diabetic patients, except for smoking habits (diabetics: 48%; non-diabetics: 64%, p = 0.002) and cardiac disease (diabetics: 45%; non-diabetics: 29...

  5. No ethical bypass of moral status in stem cell research.

    Brown, Mark

    2013-01-01

    Recent advances in reprogramming technology do not bypass the ethical challenge of embryo sacrifice. Induced pluripotent stem cell (iPS) research has been and almost certainly will continue to be conducted within the context of embryo sacrifice. If human embryos have moral status as human beings, then participation in iPS research renders one morally complicit in their destruction; if human embryos have moral status as mere precursors of human beings, then advocacy of iPS research policy that is inhibited by embryo sacrifice concerns renders one morally complicit in avoidable harms to persons. Steps may be taken to address these complicity concerns, but in the final analysis there is no alternative to achieving clarity with respect to the moral status of the human embryo. PMID:21726260

  6. New pathway to bypass the 15O waiting point

    Stefan, I; Pellegriti, M G; Dumitru, G; Navin, A; Angélique, J C; Angélique, M; Berthoumieux, E; Butà, A; Borcea, R; Coc, A; Daugas, J M; Davinson, T; Fadil, M; Grévy, S; Kiener, J; Lefebvre-Schuhl, A; Lenhardt, M; Lewitowicz, M; Negoita, F; Pantelica, D; Perrot, L; Roig, O; Laurent, M G S; Ray, I; Sorlin, O; Stanoiu, M; Stodel, C; Tatischeff, V; Thomas, J C

    2006-01-01

    Two reactions $^{15}$O(p,$\\beta^{+}$)$^{16}$O and $^{15}$O(p,$\\gamma)(\\beta^{+}$)$^{16}$O are presented as new paths to bypass the $^{15}$O waiting point in the CNO cycles. Precise measurements of the ground and excited states in $^{16}$F, obtained using H($^{15}$O,p)$^{15}$O reaction, were used to calculate the cross sections. Surprisingly the second reaction has a cross section $\\simeq$ 10$^{10}$ times larger. This can be understood to arise from the more effective feeding of the low energy wing of the ground state resonance. The implications of the latter reaction in novae explosions and x-ray bursts sites is discussed.

  7. 股腘动脉慢性长段闭塞腔内治疗134例临床分析%Endovascular treatment of Trans - Atlantic Inter - Society Consensus (TASC) Ⅱ C/D femoropopliteal lesions:an analysis of 134 cases

    殷敏毅; 蒋米尔; 黄新天; 陆民; 陆信武; 黄英; 李维敏

    2011-01-01

    Objective To summarize the endovascular treatment and the procedure - related complications for TASC II C/D femoropopliteal lesions. Methods Between January 2009 and December 2010,the clinical data of 134 patients (172 lower limbs) with TASC II C/D femoropopliteal artery occlusions who underwent endovascular treatments were retrospectively reviewed. Technical success rates, ankle brachial index,complication rates, and cumulative primary patency rates were evaluated at 3,6 and 12 months. Results The technical success rate was 90.7%. Perioperative complications occurred in 43 limbs (83 cases) and the overall complication rate was 27. 6% , including arterial dissections in 29 cases (34.9% ) ,arterial perforations in 11 (13.3% ) .arterial embolisms in 8 (9. 6% ) .puncture site hemato-mas in 16 (19.3% ),pseudoaneurysms in 5 (6.0% ) .arterial thromboses in 3 (3.6% ) .contrast allergies in 3 (3.6% ) .urinary tract hemorrhages in 2 (2.4% ) and cerebrovascular accidents in 6(7.2% ). A total of 104 patients (131 lower limbs) were followed up for a mean period of 13.1 months. Primary,assisted -primary,and secondary patency rate at 12 months was 61. 1% ,70. 2% ,81. 7% respectively. Conclusion Endovascular treatment of TASC II C/D femoropopliteal lesions has a high success rate with favorable 1 -year patency rate. Skilled technique, timely treatment of complications and regular postoperative follow - up are the keys to initial success and long - term patency.%目的 观察TASCⅡC、D型股腘动脉慢性长段闭塞腔内治疗的临床疗效,总结腔内治疗相关并发症和防治方法.方法 2009年1月至2010年12月,134例(172条下肢)TASCⅡC、D型股腘动脉闭塞患者接受腔内治疗.回顾性分析技术成功率、患肢术后临床症状、踝肱指数(ankle brachial index,ABI)变化、并发症发生率和通畅率.结果 技术成功率90.7%.43条患肢(83条次)出现并发症(27.6%).其中动脉夹层29条(34.9%),动脉穿孔11条(13.3

  8. Direct ECC bypass phenomena in the MIDAS test facility during LBLOCA reflood phase

    This paper describes the experimental results of ECC Direct Bypass Phenomena in the downcomer during the late reflood phase of LBLOCA of the reactor that adopts Direct Vessel Injection as a ECC system. The experiments have been performed in MIDAS test facility using superheated steam and water. The test condition was determined, based on the preliminary analysis of TRAC code, from modified linear scaling method of 1/4.93 length scale. To measure the direct bypass fraction according to the nozzle location, separate effect tests have been performed in case of DVI-4(farthest from broken cold leg) injection, DVI-2(closest to broken cold leg) injection, and DVI-2 and 4 injection, respectively. Also the test was carried out varying the steam flow rate greatly to investigate the effect of steam flow rate on the direct bypass fraction of ECC water. Test results show that the direct bypass fraction of ECC water depends significantly on the injected steam mass flow rate. DVI-4 tests show that the direct bypass fraction increases drastically as the steam flow rate increases. However, in DVI-2 test most of the injected ECC water penetrates into lower downcomer. The direct bypass characteristic in each of DVI-2 and DVI-4 tests is reflected into the direct bypass characteristic curve of DVI-2 and 4 test. The steam condensation reaches to the theoretically allowable maximum value

  9. Direct ECC bypass phenomena in the MIDAS test facility during LBLOCA reflood phase

    Yun, B. J.; Kweon, T. S.; Ah, D. J.; Ju, I. C.; Song, C. H.; Park, J. K. [KAERI, Taejon (Korea, Republic of)

    2001-10-01

    This paper describes the experimental results of ECC Direct Bypass Phenomena in the downcomer during the late reflood phase of LBLOCA of the reactor that adopts Direct Vessel Injection as a ECC system. The experiments have been performed in MIDAS test facility using superheated steam and water. The test condition was determined, based on the preliminary analysis of TRAC code, from modified linear scaling method of 1/4.93 length scale. To measure the direct bypass fraction according to the nozzle location, separate effect tests have been performed in case of DVI-4(farthest from broken cold leg) injection, DVI-2(closest to broken cold leg) injection, and DVI-2 and 4 injection, respectively. Also the test was carried out varying the steam flow rate greatly to investigate the effect of steam flow rate on the direct bypass fraction of ECC water. Test results show that the direct bypass fraction of ECC water depends significantly on the injected steam mass flow rate. DVI-4 tests show that the direct bypass fraction increases drastically as the steam flow rate increases. However, in DVI-2 test most of the injected ECC water penetrates into lower downcomer. The direct bypass characteristic in each of DVI-2 and DVI-4 tests is reflected into the direct bypass characteristic curve of DVI-2 and 4 test. The steam condensation reaches to the theoretically allowable maximum value.

  10. Myocardial edema and compromised left ventricular function attributable to dirofilariasis and cardiopulmonary bypass in dogs.

    Rohn, D A; Davis, K L; Mehlhorn, U; Allen, S J; Laine, G A

    1995-02-01

    We investigated the relation between left ventricular dysfunction and myocardial edema in dogs with heartworm (Dirofilaria immitis) infection that were undergoing cardiopulmonary bypass. Dogs with and without D immitis were anesthetized by continuous thiopental infusion and were mechanically ventilated. Sonomicrometry crystals were placed on the long and short axes of the left ventricle, and a Millar pressure transducer was placed in the left ventricular chamber. Pressure-volume loops were digitized and continuously recorded. Dogs with and without D immitis were placed on standard hypothermic cardiopulmonary bypass, with 1 hour of aortic cross-clamp. Wet-to-dry weight ratio corrected for residual blood volume was used to quantitate the volume of myocardial edema. Preload recruitable stroke work was used as a preload-independent index of systolic function. Tau, the isovolumic relaxation time constant, was determined to assess diastolic relaxation. Dogs with D immitis had increased baseline myocardial wet-to-dry weight ratio. After cardiopulmonary bypass, myocardial edema increased in all dogs. Acute edema attributable to cardiopulmonary bypass decreased preload recruitable stroke work in all dogs of both groups, and dogs with D immitis could not be weaned from cardiopulmonary bypass. Myocardial edema increased diastolic relaxation times (tau) in dogs with and without D immitis. We conclude that cardiopulmonary bypass and heartworm infection induce myocardial edema. This edema compromises left ventricular systolic and diastolic function making D immitis an important confounding factor in weaning dogs from cardiopulmonary bypass. PMID:7717590

  11. Pre-test CFD Calculations for a Bypass Flow Standard Problem

    Rich Johnson

    2011-11-01

    The bypass flow in a prismatic high temperature gas-cooled reactor (HTGR) is the flow that occurs between adjacent graphite blocks. Gaps exist between blocks due to variances in their manufacture and installation and because of the expansion and shrinkage of the blocks from heating and irradiation. Although the temperature of fuel compacts and graphite is sensitive to the presence of bypass flow, there is great uncertainty in the level and effects of the bypass flow. The Next Generation Nuclear Plant (NGNP) program at the Idaho National Laboratory has undertaken to produce experimental data of isothermal bypass flow between three adjacent graphite blocks. These data are intended to provide validation for computational fluid dynamic (CFD) analyses of the bypass flow. Such validation data sets are called Standard Problems in the nuclear safety analysis field. Details of the experimental apparatus as well as several pre-test calculations of the bypass flow are provided. Pre-test calculations are useful in examining the nature of the flow and to see if there are any problems associated with the flow and its measurement. The apparatus is designed to be able to provide three different gap widths in the vertical direction (the direction of the normal coolant flow) and two gap widths in the horizontal direction. It is expected that the vertical bypass flow will range from laminar to transitional to turbulent flow for the different gap widths that will be available.

  12. Clinical observation of gastric bypass in treatment of type 2 diabetes

    PU Yong-dong; YANG Bo; HE Jiao-miao; WU You-jun; WANG Yi; L(U) Gang; ZHANG Bo; WANG Yue; LIU Wei-ping; WENG Jian-feng; LI Jing-quan; CAO Zhi-yu; WANG Li; HU Xiao; DONG Li-guo; LI Yue-min; ZHAO Hua-zhou; QIN Rong

    2012-01-01

    Background Roux-en-Y gastric bypass (GBP) is the main surgical procedure used in type 2 diabetes.The objective of this study was to evaluate the different types of GBP in treatment of type 2 diabetes.Methods Patients with type 2 diabetes were randomly divided into two groups:those who underwent gastrojejunal loop anastomosis bypass and those who underwent gastrojejunal Roux-en-Y bypass.Blood glucose alterations,operation time,and operation complicatiors were observed.Results Gastrojejunal loop anastomosis bypass and gastrojejunal Roux-en-Y bypass were both effective in the treatment of selected patients with type 2 diabetes.Compared with gastrojejunal Roux-en-Y bypass,gastrojejunal loop anastomosis bypass had the advantages of easier implementation,shorter operation time,and fewer operation complications.Conclusions Gastrojejunal loop anastomosis is effective in treatment of type 2 diabetes.It is safe,easy to implement,and worthy of clinical popularization.

  13. On-pump versus off-pump coronary artery bypass surgery

    Houlind, Kim Christian

    2013-01-01

    Off pump coronary artery bypass surgery has been purported to be safer than conventional coronary artery bypass surgery performed using cardiopulmonary bypass. This theory was supported by a number of early series, but failed to be confirmed by a number of small, randomized controlled trials...... . Conversely, it has been suggested that revascularization after off pump surgery is associated with fewer grafts and lower graft patency, potentially leading to a higher risk of cardiovascular morbidity and need for repeated, coronary interventions. Since 2009, three major randomized controlled trials have...

  14. Experimental Study on Airflow Reversal Within Bypass Branch During Mine Fire

    周福宝; 王德明; 周延

    2001-01-01

    Based on the analysis of conditions for airflow reversal within a bypass branch, the airflow reversal phenomena were successfully simulated in the laboratory experiments. Data obtained indicate that airflow reversal within a bypass branch is mainly caused by fire pressure yielded in the combustion branch. In addition, the maximum reversal quantity of airflow occurs in step with the highest temperature of fire, the highest concentration of CO2 and the lowest concentration of O2. Moreover, the time that fire size reaches the maximum value corresponds to the time airflow reversal in the bypass branch is most possible. The results are of great significance for guiding rescue work to avoid airflow reversal.

  15. On the Modelling of Steady Generalized Newtonian Flows in a 3D Coronary Bypass

    Vimmr, Jan; Jonášová, Alena

    2008-01-01

    Blood's non-Newtonian behaviour is investigated in an idealized coronary 3D bypass model, which includes both the proximal and distal parts of the occluded native artery and the connected end-to-side bypass graft. Considering the blood to be a generalized Newtonian fluid, the shear-dependent viscosity is given by two well-known macroscopic non-Newtonian models (the Carreau-Yasuda model and the modified Cross model). Both non-Newtonian steady flow fields are analyzed with regard to the bypass ...

  16. Robotic-assisted aortic valve bypass (apicoaortic conduit) for aortic stenosis.

    Gammie, James S; Lehr, Eric J; Griffith, Bartley P; Dawood, Murtaza Y; Bonatti, Johannes

    2011-08-01

    Aortic valve bypass (AVB [apicoaortic conduit]) surgery consists of the construction of a valved conduit between the left ventricular apex and the descending thoracic aorta. In our institution, AVB is routinely performed without cardiopulmonary bypass or manipulation of the ascending aorta or native aortic valve. We report the case of an 83-year-old man with severe symptomatic bioprosthetic aortic stenosis, chronic thrombocytopenia, and a patent bypass graft who underwent robotically assisted beating-heart AVB through an anterior minithoracotomy. The distal anastomosis was constructed entirely using robotic telemanipulation. Robotic assistance enables the performance of beating-heart AVB through a small incision. PMID:21801931

  17. Analysis of pesticides in surface water and sediment from Yolo Bypass, California, 2004-2005

    Smalling, Kelly L.; Orlando, James L.; Kuivila, Kathryn M.

    2005-01-01

    Inputs to the Yolo Bypass are potential sources of pesticides that could impact critical life stages of native fish. To assess the direct inputs during inundation, pesticide concentrations were analyzed in water, in suspended and bed-sediment samples collected from six source watersheds to the Yolo Bypass, and from three sites within the Bypass in 2004 and 2005. Water samples were collected in February 2004 from the six input sites to the Bypass during the first flood event of the year representing pesticide inputs during high-flow events. Samples were also collected along a transect across the Bypass in early March 2004 and from three sites within the Bypass in the spring of 2004 under low-flow conditions. Low-flow data were used to understand potential pesticide contamination and its effects on native fish if water from these areas were used to flood the Bypass in dry years. To assess loads of pesticides to the Bypass associated with suspended sediments, large-volume water samples were collected during high flows in 2004 and 2005 from three sites, whereas bed sediments were collected from six sites in the fall of 2004 during the dry season. Thirteen current-use pesticides were detected in surface water samples collected during the study. The highest pesticide concentrations detected at the input sites to the Bypass corresponded to the first high-flow event of the year. The highest pesticide concentrations at the two sites sampled within the Bypass during the early spring were detected in mid-April following a major flood event as the water began to subside. The pesticides detected and their concentrations in the surface waters varied by site; however, hexazinone and simazine were detected at all sites and at some of the highest concentrations. Thirteen current-use pesticides and three organochlorine insecticides were detected in bed and suspended sediments collected in 2004 and 2005. The pesticides detected and their concentrations varied by site and sediment

  18. Effect of short-acting beta blocker on the cardiac recovery after cardiopulmonary bypass

    Qian Yanning

    2011-08-01

    Full Text Available Abstract The objective of this study was to investigate the effect of beta blocker on cardiac recovery and rhythm during cardiac surgeries. Sixty surgical rheumatic heart disease patients were received esmolol 1 mg/kg or the same volume of saline prior to removal of the aortic clamp. The incidence of cardiac automatic re-beat, ventricular fibrillation after reperfusion, the heart rate after steady re-beat, vasoactive drug use during weaning from bypass, the posterior parallel time and total bypass time were decreased by esmolol treatment. In conclusion: Esmolol has a positive effect on the cardiac recovery in cardiopulmonary bypass surgeries.

  19. Severe scurvy after gastric bypass surgery and a poor postoperative diet

    Hansen, Esben P K; Metzsche, Carsten; Henningsen, Emil;

    2012-01-01

    After bariatric gastric bypass surgery patients are at risk of developing micronutrient deficiencies. If gastric bypass surgery is followed by a vitamin deficient diet the patients have a risk of developing vitamin-C deficiency. When spontaneous ecchymosis is observed in the skin, in at-risk pati......-risk patients, scurvy must be considered. When treated with large doses of vitamin-C the symptoms of scurvy rapidly improve even if the patient has developed multiple organ dysfunction syndrome. KEYWORDS: Scurvy; Gastric bypass surgery; Multiorgan dysfunction....

  20. A simple technique can reduce cardiopulmonary bypass use during lung transplantation

    Marcos N. Samano

    2016-04-01

    Full Text Available Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure.

  1. ROBOTIC ROUX-EN-Y GASTRIC BYPASS: OPERATIVE RESULTS IN 100 PATIENTS

    DOMENE, Carlos Eduardo; VOLPE, Paula; HEITOR, Frederico A.

    2014-01-01

    Background Laparoscopic gastric bypass is gold-standard for morbid obesity treatment. Aim To describe the results of robotic gastric bypass for morbid obesity patients. Method Were operated on 100 morbidly obese patients through totally robotic gastric bypass between 2013 and 2014. They were 83% female. The age ranged from 20 to 65 years old (medium 48,5 years); the body mass index varied between 38-67 (medium 42,3 kg/cm2). The procedure was designed with 3 cm long gastric pouch, 1 m biliopan...

  2. By-Pass Diode Temperature Tests of a Solar Array Coupon under Space Thermal Environment Conditions

    Wright, Kenneth H.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon

    2016-01-01

    By-Pass diodes are a key design feature of solar arrays and system design must be robust against local heating, especially with implementation of larger solar cells. By-Pass diode testing was performed to aid thermal model development for use in future array designs that utilize larger cell sizes that result in higher string currents. Testing was performed on a 56-cell Advanced Triple Junction solar array coupon provided by SSL. Test conditions were vacuum with cold array backside using discrete by-pass diode current steps of 0.25 A ranging from 0 A to 2.0 A.

  3. Vascularized Nerve Bypass Graft: A Case Report of an Additional Treatment for Poor Sensory Recovery.

    Usami, Satoshi; Tanaka, Kentaro; Ohkubo, Alisa; Okazaki, Mutsumi

    2016-04-01

    End-to-side neurorrhaphy has proven effective in basic research and in clinical application. One of the methods of end-to-side neurorrhaphy, nerve bypass technique, has been reported and axon regeneration has been proven. In clinical application, the utility of the nerve bypass technique has been revealed in some cases; however, these bypasses were performed using nonvascularized nerves. We initially used the vascularized nerve bypass graft technique with the sural nerve as a secondary clinical procedure after median nerve injury in a 61-year-old patient and achieved motor and sensory nerve regeneration, as supported by a nerve conduction study and clinical sensory test. This technique has the potential to become one of the choices for salvage procedure of severe nerve injury. PMID:27200248

  4. Off-Pump Versus On-Pump Coronary Artery Bypass Grafting

    Møller, Christian H; Steinbrüchel, Daniel A

    2014-01-01

    Coronary artery bypass grafting (CABG) remains the preferred treatment in patients with complex coronary artery disease. However, whether the procedure should be performed with or without the use of cardiopulmonary bypass, referred to as off-pump and on-pump CABG, is still up for debate....... Intuitively, avoidance of cardiopulmonary bypass seems beneficial as the systemic inflammatory response from extracorporeal circulation is omitted, but no single randomized trial has been able to prove off-pump CABG superior to on-pump CABG as regards the hard outcomes death, stroke or myocardial infarction....... In contrast, off-pump CABG is technically more challenging and may be associated with increased risk of incomplete revascularization. The purpose of the review is to summarize the current literature comparing outcomes of off-pump versus on-pump coronary artery bypass surgery....

  5. Emergency Coronary Artery Bypass Grafting: Indications and Outcomes from 2003 through 2013

    Schumer, Erin M.; Chaney, John H.; Trivedi, Jaimin R.; Linsky, Paul L.; Williams, Matthew L.; Slaughter, Mark S

    2016-01-01

    Emergency coronary artery bypass grafting (CABG) is associated with increased in-hospital mortality rates and adverse events. This study retrospectively evaluated indications and outcomes in patients who underwent emergency CABG.

  6. Bypass Transitional Flow Calculations Using a Navier-Stokes Solver and Two-Equation Models

    Liuo, William W.; Shih, Tsan-Hsing; Povinelli, L. A. (Technical Monitor)

    2000-01-01

    Bypass transitional flows over a flat plate were simulated using a Navier-Stokes solver and two equation models. A new model for the bypass transition, which occurs in cases with high free stream turbulence intensity (TI), is described. The new transition model is developed by including an intermittency correction function to an existing two-equation turbulence model. The advantages of using Navier-Stokes equations, as opposed to boundary-layer equations, in bypass transition simulations are also illustrated. The results for two test flows over a flat plate with different levels of free stream turbulence intensity are reported. Comparisons with the experimental measurements show that the new model can capture very well both the onset and the length of bypass transition.

  7. THE BASIC LAWS AND FEATURES OF CYTOKINE DYNAMICS IN PROCESS AND EARLY TERMS AFTER CARDIOPULMONARY BYPASS

    S. I. Suskov

    2011-01-01

    Full Text Available The basic variants of cytokines reactions defining type of organ dysfunctions are revealed in the course of car- diopulmonary bypass and in the early postoperative period. Their character and expression, depends on gravity preoperative an immunodeficiency and initial degree of heart insufficiency. Diphasic dynamics of development of system inflammatory reaction is confirmed after cardiopulmonary bypass: increase of levels proinflammatory cytokines is in the first phase and anti-inflammatory cytokines with development immunodepression and cellular anergy in is the second phase. Also, key role IL-1Ra is revealed in restraint of hyperactivation of system inflam- matory reaction. Blood whey levels IL-6, IL-8, G-CSF, TNF-α and IL-1Ra should be defined to cardiopulmonary bypass, in 10–12 hours, 24 hours and 3 days after cardiopulmonary bypass and may be used as prognostic criteria of development of postoperative complications. 

  8. Quality of Life After Bypass Surgery in Patients with Chest Pain and Heart Failure

    Annals of Internal Medicine Summaries for Patients Quality of Life After Bypass Surgery in Patients With Chest Pain and Heart Failure The full report is titled “Quality-of-Life Outcomes With Coronary Artery ...

  9. Utilising cardiopulmonary bypass for cancer surgery. Malignancy-induced protein C deficiency and thrombophilia.

    Marshall, C

    2012-02-03

    Cardiopulmonary bypass has evolved over the last 30 years. It is an important tool for the cardiac surgeon today and also has applications in non-cardiac operations such as surgery to extract tumours. Such patients undergoing surgery for cancer may be at an increased risk of a thromboembolic event post surgery, due to disturbances in the normal clotting pathway leading to hypercoagulability. One such disturbance is malignancy-induced Protein C deficiency. A deficiency of Protein C can cause hypercoagulabitity. Recent studies have examined cardiopulmonary bypass and inherited Protein C deficiency. However, surgery for cancer patients with a malignancy-induced Protein C deficiency involving cardiopulmonary bypass has not been reported. Surgery using CPB in these patients may result in increased morbidity and mortality. The objective of this article is to review the literature in order to discuss the occurrence, the aetiology and possible management of cancer patients with malignancy-induced Protein C deficiencies that require cardiopulmonary bypass for their surgery.

  10. Decline in Health-Related Quality of Life 6 Months After Coronary Artery Bypass Graft Surgery

    El Baz, Noha; Pedersen, Susanne S.; van Dijk, Jitse P; Wynia, Klaske; Reijneveld, Sijmen A

    2013-01-01

    Although coronary artery bypass graft (CABG) is known to improve health-related quality of life (HRQoL), this improvement does not seem to be realized in all patients who had undergone CABG surgery....

  11. Extracranial–intracranial bypass for Takayasu’s arteritis: A case report

    Richard M. Young, M.D.

    2014-12-01

    Conclusion: STA–MCA bypass to enhance cerebral blood flow in the setting of stroke symptoms due to Takayasu’s arteritis can serve as a bridge before definitive cardiothoracic treatment of the great vessels.

  12. Effects of cardiopulmonary bypass on propofol pharmacokinetics and bispectral index during coronary surgery

    Ricardo Antonio G. Barbosa

    2009-03-01

    Full Text Available PURPOSE: Cardiopulmonary bypass is known to alter propofol pharmacokinetics in patients undergoing cardiac surgery. However, few studies have evaluated the impact of these alterations on postoperative pharmacodynamics. This study was designed to test the hypothesis that changes in propofol pharmacokinetics increase hypnotic effects after cardiopulmonary bypass. METHODS: Twenty patients scheduled for on-pump coronary artery bypass graft (group, n=10 or off-pump coronary artery bypass graft (group, n=10 coronary artery bypass grafts were anesthetized with sufentanil and a propofol target controlled infusion (2.0 µg/mL. Depth of hypnosis was monitored using the bispectral index. Blood samples were collected from the induction of anesthesia up to 12 hours after the end of propofol infusion, at predetermined intervals. Plasma propofol concentrations were measured using high-performance liquid chromatography, followed by a non-compartmental propofol pharmacokinetic analysis. Data were analyzed using ANOVA, considering p<0.05 as significant. RESULTS: After cardiopulmonary bypass, despite similar plasma propofol concentrations in both groups, bispectral index values were lower in the on-pump coronary artery bypass graft group. Time to extubation after the end of propofol infusion was greater in the on-pump coronary artery bypass graft group (334 ± 117 vs. 216 ± 85 min, p = 0.04. Patients undergoing cardiopulmonary bypass had shorter biological (1.82 ± 0.5 vs. 3.67 ± 1.15h, p < 0.01 and terminal elimination (6.27 ± 1.29 vs. 10.5h ± 2.18, p < 0.01 half-life values, as well as higher total plasma clearance (28.36 ± 11.40 vs.18.29 ± 7.67 mL/kg/min, p = 0.03, compared to patients in the off-pump coronary artery bypass graft group. CONCLUSION: Aside from the increased sensitivity of the brain to anesthetics after cardiopulmonary bypass, changes in propofol pharmacokinetics may contribute to its central nervous system effects.

  13. Air embolism during off-pump coronary artery bypass graft surgery -A case report-

    Chang, Choo-Hoon; Shin, Young Hee; Cho, Hyun-Sung

    2012-01-01

    There have been several reports of gas embolism occurring during off-pump coronary artery bypass graft (OPCAB) surgery. However, all these cases of air embolism were associated with the repair of venous circulation, using a CO2 blower. In this report, we describe a rare case of air embolism in the coronary arteries associated with the use of a CO2 blower during OPCAB. There was no injury to the veins during OPCAB. The air embolism was treated successfully with cardiopulmonary bypass.

  14. Anesthetic considerations for the patients with off-pump coronary artery bypass grafting

    2005-01-01

    New surgical techniques for coronary artery bypass graft (CABG) have been explored in order to minimize disfiguring scars, avoid cardiopulmonary bypass and decrease hospital residence and costs etc. Improved surgical expertise can perform the procedures in some high-risk patients such as poor left ventricular function, redo CABG, advanced age and renal dysfunction etc. Intraoperatively there is an obligatory period of myocardial ischemia, which may lead to significant hemodynamic consequences. It is a quite challenge to anesthetist in managing the intraoperative patient.

  15. The incidence of ureteral obstruction secondary to aorto-femoral bypass surgery. A prospective study

    Henriksen, L O; Mejdahl, Steen; Petersen, F; Tønnesen, Knud Henrik; Holstein, P E

    1988-01-01

    Hydronephrosis is reported to be an infrequent complication of aorto-femoral bypass operations. To define the true incidence of this complication, renography (131I-Hippuran) and renal scintigraphy (99 Technetium) were performed both pre- and postoperatively on 56 asymptomatic patients following s...... successful aortic reconstruction. No patient developed signs of ureteral obstruction. It is concluded that hydronephrosis is a rare complication to aorto-femoral bypass surgery and postoperative control is only indicated in patients with symptoms from the urinary tract....

  16. Innovations in Pedriatic Cradiopulmonary Bypass: a continuous process of quality improvement

    Golab, Hanna

    2011-01-01

    textabstractCardiopulmonary bypass (CPB) is defined as a technique that temporarily replaces the function of the heart and lungs, maintaining an adequate blood circulation and oxygen content of the body during surgery of the heart and great vessels. The current practice of cardiopulmonary bypass was achieved through the efforts of a numbers of individuals who believed that artificial cardiopulmonary support could replace the body’s own circulatory and respiratory systems. Collaborative effort...

  17. Stress analysis method for clearance-fit joints with bearing-bypass loads

    Naik, R. A.; Crews, J. H., Jr.

    1989-01-01

    Within a multi-fastener joint, fastener holes may be subjected to the combined effects of bearing loads and loads that bypass the hole to be reacted elsewhere in the joint. The analysis of a joint subjected to search combined bearing and bypass loads is complicated by the usual clearance between the hole and the fastener. A simple analysis method for such clearance-fit joints subjected to bearing-bypass loading has been developed in the present study. It uses an inverse formulation with a linear elastic finite-element analysis. Conditions along the bolt-hole contact arc are specified by displacement constraint equations. The present method is simple to apply and can be implemented with most general purpose finite-element programs since it does not use complicated iterative-incremental procedures. The method was used to study the effects of bearing-bypass loading on bolt-hole contact angles and local stresses. In this study, a rigid, frictionless bolt was used with a plate having the properties of a quasi-isotropic graphite/epoxy laminate. Results showed that the contact angle as well as the peak stresses around the hole and their locations were strongly influenced by the ratio of bearing and bypass loads. For single contact, tension and compression bearing-bypass loading had opposite effects on the contact angle. For some compressive bearing-bypass loads, the hole tended to close on the fastener leading to dual contact. It was shown that dual contact reduces the stress concentration at the fastener and would, therefore, increase joint strength in compression. The results illustrate the general importance of accounting for bolt-hole clearance and contact to accurately compute local bolt-hole stresses for combined bearings and bypass loading.

  18. Outcome of Coronary Artery Bypass Grafts: Comparison between on Pump and off Pump

    Rasoul Ibrahim Abdulrahman; Rezayat Parvizi

    2010-01-01

    The present study was undertaken to compare the in hospital results of coronary artery bypass graft (CABG) with (on pump) or without (off pump) cardiopulmonary bypass (CPB). Data were collected on all first-time isolated CABGs with saphenous vein and/or artery grafts at Shahid Madani Hospital in Tabriz-Iran, between 2006 and 2009. Age and clinical profile were marched between on pump and off pump group patients. Patients with concomitant cardiac operations or beating pump technique were exclu...

  19. C-terminales Pro-Endothelin-1 als Verlaufsmarker bei herzchirurgischen Operationen mit kardiopulmonalem Bypass

    J. Köster

    2009-01-01

    Bei herzchirurgischen Operationen mit kardiopulmonalem Bypass beeinflusst die Erhöhung des Endothelin-1 (ET-1) Körperfunktionen negativ. Das ist eine Synthesevorstufe des ET-1. Es wurde zu 12 Messzeitpunkten der Verlauf des C-terminalen Pro-ET1 nach herzchirurgischen Engriffen mit kardiopulmonalem Bypass sowie das Langzeitoutcome bei 123 Patienten prospektiv mittels Immunossay bestimmt. Nach 2 Jahren wurde die Überlebensrate erhoben. Es zeigte sich ein spezifischer Verlauf: nach Einleitung de...

  20. Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor

    Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.

  1. Effect of in-hospital physical activity on cardiovascular prognosis in lower extremity bypass for claudication

    Matsuo, Tomohiro; Sakaguchi, Taichi; Ishida, Atsuhisa; Yuguchi, Satoshi; Saito, Kazuya; Nakajima, Masaharu; Ujikawa, Takuya; Morisawa, Tomoyuki; Chikazawa, Genta; Takahashi, Tetsuya

    2015-01-01

    [Purpose] This study aimed to evaluate the effect of in-hospital physical activity on patient prognosis after lower extremity bypass surgery for peripheral arterial disease. [Subjects and Methods] A total of 13 patients (16 limbs; 11 males and 2 females; mean age [standard deviation], 72.8 [5.9] years) who underwent lower extremity bypass surgery for Fontaine stage 2 peripheral arterial disease were included in this study and assigned to either an active group (n = 6) to perform increased phy...

  2. Numerical simulation of an alternative to prevent hydrates formation in a bypass section

    Almeida, Lucilla Coelho; Oliveira Junior, Joao Americo Aguirre; Fonte, Clarissa Bergman [Engineering Simulation and Scientific Software Ltda. (ESSS), Florianopolis, SC (Brazil); Silva, Fabricio Soares da; Moraes, Carlos Alberto Capela [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    This work presents the use of Computational Fluid Dynamics to evaluate the feasibility of MEG (monoethylene glycol) injection as an alternative to prevent hydrate formation in a bypass section, present in an inlet module of a separation device of a subsea separation system. As the bypass section is open to the main pipeline, MEG will probably be dragged due to secondary flows generated by the main flow stream. The MEG removal rate is estimated, as well as the internal heat transfer between the currents and the heat loss to the external environment in order to estimate the temperature in the equipment. In a first step, the MEG removal was evaluated considering the heat transfer between the liquid phase (composed of water, oil and MEG) and the gas phase as well as the heat transfer by forced convection to the external environment. In a second step, the influence of a thermal insulation layer around the bypass line, reducing the heat loss to the external environment, was studied. Both simulations (with or without thermal insulation) showed the establishment of secondary flows in the open connection between the main line and bypass line, promoting the removal of MEG from the bypass section and enabling other components of the liquid phase and/or gas to enter in the bypass line. This MEG removal is faster when thermal isolation was considered, due to the fact that higher temperatures are established in the bypass, maintaining the liquid phase with lower densities and viscosities. With regard to temperature, the insulation was able to keep higher temperatures at the bypass line than those obtained without insulation, indicating that the combination of MEG injection and thermal insulation may be able to avoid the critical condition for hydrate formation. (author)

  3. Self-priming Hemodynamic Reservoir and Inline Flow Meter for a Cardiopulmonary Bypass Simulation

    Raasch, David; Austin, Jon; Tallman, Richard

    2010-01-01

    Simulator exercises are used at Midwestern University to augment academic and laboratory training toward consolidating particular skills, increasing situation awareness, and preparing the student for practice within the team environment of an operating room. This paper describes an enhanced cardiopulmonary bypass simulator consisting of a self-priming hemodynamic reservoir that includes an inline flow meter. A typical cardiopulmonary bypass adult perfusion circuit was assembled using a roller...

  4. Ventilation during cardiopulmonary bypass did not attenuate inflammatory response or affect postoperative outcomes

    Durukan, Ahmet Baris; Gurbuz, Hasan Alper; Ucar, Halil Ibrahim; Yorgancioglu, Cem; Salman, Nevriye; Utku Unal, Ertekin

    2013-01-01

    Introduction Cardiopulmonary bypass causes a series of inflammatory events that have adverse effects on the outcome. The release of cytokines, including interleukins, plays a key role in the pathophysiology of the process. Simultaneously, cessation of ventilation and pulmonary blood flow contribute to ischaemia–reperfusion injury in the lungs when reperfusion is maintained. Collapse of the lungs during cardiopulmonary bypass leads to postoperative atelectasis, which correlates with the amount...

  5. Bypassing health facilities for childbirth: a multilevel study in three districts of Gujarat, India

    Salazar, Mariano; Vora, Kranti; de Costa, Ayesha

    2016-01-01

    Background: Bypassing available facilities for childbirth has important implications for maternal health service delivery and human resources within a health system. The results are the additional expenses imposed on the woman and her family, as well as the inefficient use of health system resources. Bypassing often indicates a lack of confidence in the care provided by the facility nearest to the mother, which implies a level of dysfunctionality that the health system needs to address. Over ...

  6. An Investigation of the Socioeconomic Impacts of Tri-State Bypass, 1970-2000

    Yeboah, Osei-Agyeman; Shaik, Saleem; Hatch, L. Upton

    2003-01-01

    Geographical information systems and econometric tools were used to determine the socioeconomic impacts of bypasses in Atlanta-Birmingham Metropolitan area. Mean household income and per capita income of county is separately used as a proxy for anticipated bypass impact as a function, of socioeconomic variables: farm income, farm employment, non-farm employment, age groups, and population density. The cross-sectional and the time series data were pooled together and estimated as panel data. R...

  7. Effects of different PEEP levels on respiratory mechanics and oxygenation after coronary artery bypass grafting

    Daniel Lago Borges; Vinícius José da Silva Nina; Marina de Albuquerque Gonçalves Costa; Thiago Eduardo Pereira Baldez; Natália Pereira dos Santos; Ilka Mendes Lima; Eduardo Durans Figuerêdo; Josimary Lima da Silva Lula

    2013-01-01

    OBJECTIVE: To compare the effects of different levels of positive end-expiratory pressure on respiratory mechanics and oxygenation indexes in the immediate postoperative period of coronary artery bypass grafting. METHODS: Randomized clinical trial in which 136 patients underwent coronary artery bypass grafting between January 2011 and March 2012 were divided into three groups and admitted to mechanical ventilation with different positive end-expiratory pressure levels: Group A, 5 cmH2O (n=44)...

  8. The Effect of Low Tidal Volume Ventilation during Cardiopulmonary Bypass on Postoperative Pulmonary Function

    Gholamreza Safarpour; Mohammad Hosein Bakhshaei; Ahmad Moradi; Afshin Farhanchi; Maryam Davoudi

    2010-01-01

    Background: Postoperative pulmonary dysfunction is one of the most frequent complications after cardiac surgery and it is believed to result from the use of cardiopulmonary bypass (CPB). In this study, we investigated the effect of low tidal volume ventilation during CPB on postoperative gas exchange and lung mechanics. Methods: This prospective randomized study included 100 patients undergoing elective coronary artery bypass grafting. In 50 patients, low tidal volume ventilation [tidal volum...

  9. A cryogenic heat exchanger with bypass and throttling and its thermodynamic analysis

    Tao, X.; Liu, D. L.; Wang, L. Y.; Shen, J.; Gan, Z. H.

    2015-12-01

    A precooled Joule-Thomson (J-T) cooler refrigerates at liquid helium temperature. Its third stage heat exchanger works below 20 K. Hot fluid cannot be sufficiently cooled due to nonidealism of the heat exchanger and helium-4 properties. In a J-T cycle of low pressure ratio, the heat exchanger with bypass and throttling improves the refrigeration capacity. Bypass and throttling reduces the temperature difference and entropy generation within the heat exchanger.

  10. CARDIOPULMONARY BYPASS WITH AUTOLOGOUS LUNG AS SUBSTITUTE FOR ARTIFICIAL OXYGENATOR ATTENUATES INFLAMMATORY RESPONSIVE INSPIRATORY DYSFUNCTION

    HUANG Hui-min; KONG Xiang; WANG Wei; ZHU De-ming; ZHANG Hai-bo

    2007-01-01

    Objective To study if using autologous lung as a substitute of oxygenator in cardiopulmonary bypass is better than the conventional cardiopulmonary bypass with artificial oxygenator in pulmonary preservation.Methods Twelve piglets were randomly divided into two groups ( n = 6). The isolated lung perfusion model was established. The experimental animals underwent continuous lung perfusion for about 120 min. While the control animals underwent 90 min lung ischemia followed by 30 min reperfusion. Another 12 piglets were randomly divided into two groups ( n =6). The experimental animals underwent bi-ventricular bypass with autologous lung perfusion.While control animals underwent conventional cardiopulmonary bypass with artificial oxygenator. The bypass time and aortic cross clamping time were 135 min and 60 min respectively for each animal. The lung static compliance ( Cstat), alveolus-artery oxygen difference ( PA-aO2 ), TNF-α, IL-6 and wet to dry lung weight ratio (W/D) were measured. Histological and ultra-structural changes of the lung were also observed after bypass. Results After either isolated lung perfusion or cardiopulmonary bypass, the Cstat decreased, the PA-aO2 increased and the content of TNF-α increased for both groups, but the changes of experimental group were much less than those of control group. The lower W/D ratio and mild pathological changes in experimental group than those in control group were also demonstrated. Conclusion Autologous lung is able to tolerate the nonpalsatile perfusion. It can be used as a substitute to artificial ogygenator in cardiopulmonary bypass to minimize the inflammatory pulmonary injury caused mainly by ischemic reperfusion and interaction of the blood to the non-physiological surface of artificial oxygenator.

  11. Severe Scurvy After Gastric Bypass Surgery and a Poor Postoperative Diet

    Hansen, Esben P.K.; Metzsche, Carsten; Henningsen, Emil; Toft, Palle

    2012-01-01

    After bariatric gastric bypass surgery patients are at risk of developing micronutrient deficiencies. If gastric bypass surgery is followed by a vitamin deficient diet the patients have a risk of developing vitamin-C deficiency. When spontaneous ecchymosis is observed in the skin, in at-risk patients, scurvy must be considered. When treated with large doses of vitamin-C the symptoms of scurvy rapidly improve even if the patient has developed multiple organ dysfunction syndrome. Keywords Scurv...

  12. Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor

    Richard Schultz

    2012-04-01

    Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.

  13. Ubiquitin-dependent DNA damage bypass is separable from genome replication

    Daigaku, Yasukazu; Davies, Adelina A.; Ulrich, Helle D.

    2010-01-01

    Postreplication repair (PRR) is a pathway that allows cells to bypass or overcome lesions during DNA replication1. In eukaryotes, damage bypass is activated by ubiquitylation of the replication clamp PCNA through components of the RAD6 pathway2. Whereas monoubiquitylation of PCNA allows mutagenic translesion synthesis by damage-tolerant DNA polymerases3-5, polyubiquitylation is required for an error-free pathway that likely involves a template switch to the undamaged sister chromatid6. Both t...

  14. Pregnancy following gastric bypass surgery (Roux-en-Y) for morbid obesity

    Anasiudu, R; Gajjar, K; Osoba, O; Soliman, N

    2011-01-01

    Morbidly obese women are at increased risk of obstetric complications and poor neonatal outcomes. Gastric bypass surgery is being performed with increased frequency in reproductive-aged women to treat morbid obesity. Both maternal and fetal complications have been reported in women who underwent gastric bypass surgery. Current recommendations advise delaying pregnancy for at least 1 year following bariatric surgery. This guideline is meant to discourage women from becoming pregnant during the...

  15. Randomised trial of endoscopic endoprosthesis versus operative bypass in malignant obstructive jaundice

    Andersen, J R; Sørensen, S M; Kruse, A;

    1989-01-01

    In patients with obstructive jaundice caused by malignant stricture of the extrahepatic bile duct we compared survival time, complication rates, hospitalisation requirements, and quality of life after palliation by endoscopic endoprosthesis or bypass surgery. During diagnostic endoscopic...... survival between treatment groups or randomisation groups. No differences were found when other variables were compared. We conclude, that palliation of obstructive jaundice in malignant bile duct obstruction with endoscopically introduced endoprosthesis is as effective as operative bypass....

  16. Esmolol added in repeated, cold, oxygenated blood cardioplegia improves myocardial function after cardiopulmonary bypass

    Dahle, Geir Olav; Salminen, Pirjo-Riitta; Moen, Christian Arvei; Eliassen, Finn; Jonassen, Anne K.; Haaverstad, Rune; Matre, Knut; Grong, Ketil

    2015-01-01

    Objective: This study investigated if the β-receptor blocking agent esmolol, added to standard oxygenated blood cardioplegia, improved myocardial function after weaning from bypass. Design: A block-randomized, blinded study. Setting: A university laboratory. Participants: Twenty anesthetized pigs, Norwegian Landrace. Interventions: After cardiopulmonary bypass, cardiac arrest was induced with cold (12°C), oxygenated blood cardioplegia, enriched with either esmolol or vehi...

  17. Implementation of a graft surveillance programme for infrainuginal vascular bypass surgery

    Cassar, Noel; Dunjic, Branko; Cassar, Kevin

    2010-01-01

    Aim: Patients undergoing bypass graft placement in the lower limb are often entered into a graft surveillance programme using duplex scanning. The aim of this programme is to identify stenoses in vein grafts before they become symptomatic and treat these by angioplasty or surgery, thus prolonging the patency of the graft. This paper aims at reporting on the progress and viability of this programme at Mater Dei Hospital, Malta. Method: Infrainguinal bypass grafts carried out between July 2007 ...

  18. Improved Environmental Impact with Diversion of Perfusion Bypass Circuit to Municipal Solid Waste

    DeBois, William; Prata, Jessica; Elmer, Barbara; Liu, Junli; Fominyam, Edward; Salemi, Arash

    2013-01-01

    The project goal was to reduce waste disposal volume, costs and minimize the negative impact that regulated waste treatment and disposal has on the environment. This was accomplished by diverting bypass circuits from the traditional regulated medical waste (RMW) to clear bag waste, or municipal solid waste (MSW). To qualify circuits to be disposed of through MSW stream, the circuits needed to be void of any free-flowing blood and be “responsibly clear.” Traditionally the perfusion bypass circ...

  19. Assessment of extracranial-intracranial bypass patency with 64-slice multidetector computerized tomography angiography

    Extracranial-intracranial (EC/IC) bypass is a useful procedure for the treatment of cerebral vascular insufficiency or complex aneurysms. We explored the role of multidetector computed tomography angiography (MDCTA), instead of digital subtraction angiography (DSA), for the postoperative assessment of EC/IC bypass patency. We retrospectively analyzed a consecutive series of 21 MDCTAs from 17 patients that underwent 25 direct or indirect EC/IC bypass procedures between April 2003 and November 2007. Conventional DSA was available for comparison in 13 cases. MDCTA used a 64-slice MDCT scanner (Aquilion 64, Toshiba). The proximal and distal patencies were analyzed independently on MDCTA and DSA by a neuroradiologist and a neurosurgeon. The bypass was considered patent when the entire donor vessel was opacified without discontinuity from proximal to distal ends and was visibly in contact with the recipient vessel. MDCTA depicted the patency status in every patient. Bypasses were patent in 22 cases, stenosed in one, and occluded in two. DSA always confirmed the results of the MDCTA (sensitivity = 100%, 95% CI = 0.655-1.0; specificity 100%, 95% CI = 0.05-1.0). MDCTA is a non-invasive and accurate exam to assess the postoperative EC/IC bypass patency and is a promising technique in routine follow-up. (orig.)

  20. Graft patency in off-pump and conventional coronary artery bypass grafting for treatment of triple vessel coronary disease

    胡盛寿; 王小启; 宋云虎; 吕锋

    2003-01-01

    Objective To compare graft patency in off-pump and conventional coronary artery bypass grafting by using the transit time flow meter in the treatment of triple vessel coronary artery disease. Methods Between June 2000 and April 2001, 60 patients with triple vessel coronary artery disease underwent coronary artery bypass grafting. They were divided into two groups: off-pump and conventional coronary artery bypass. All completed grafts were tested intraoperatively using Transit Time Flow Measurement (TTFM). Preoperative and postoperative variables of the two groups were also compared. Results There were no significant differences in sex, age, weight, acute or remote myocardial infarction, hypertension, diabetes and type of bypass grafts between the two groups. The number of bypass grafts and the assisted respiratory time of the off-pump coronary artery bypass grafting (OPCAB) group were significantly less than those of the conventional coronary artery bypass grafting (CCABG) group. The flow and pulsatile index (PI) of the left anterior descending artery bypass grafts and the right coronary artery bypass grafts were not significantly different between the OPCAB and CCABG groups. The flow of OM in the CCABG group with the multiple anastomosis site of sequential grafts was higher than that in the OPCAB group. Diffused narrow coronary artery bypass grafts in both groups had less flow.Conclusion No signficant differences in graft patency were observed in patients with triple vessel coronary artery disease who had undergone OPCAB or CCABG.

  1. A pulsatile pump for cardiopulmonary bypass and its clinical use.

    Sasaki, Y; Kawai, T; Nishiyama, K; Murayama, Y; Toda, S; Wada, T; Kitaura, K; Sato, S; Kadowaki, M; Kanki, Y

    1988-09-01

    A pulsatile pump driven by a coil spring, which was designed and constructed by us, is described in this report. It consists of two main parts, a disposable blood chamber and a driving section. The blood chamber has two leaflet valves and a piston, which is covered with two bellofram rolling diaphragms and moves into the housing to draw in and eject the blood. The driving section consists of three cams, an electric motor and a coil spring. The ejection force is wholly produced by the compressed coil spring and is transmitted to the piston in the blood chamber by a rod. This pump allows the ejection pressure, the beat rates, and the stroke volume all to be changed independently. The performance of the pump was tested by using a circulation model where the beat rate was adjusted from 30 to 250 bpm. The output subsequently increased from 0.8 l/min to 5.7 l/min and the stroke volume, from 20.4 ml to 36.7 ml. This new pump has been used for clinical cardiopulmonary bypasses in 24 patients of open heart surgery and the pressure traces during perfusion resembled those of the patients' own hearts. PMID:3230723

  2. In situ saphenous vein bypass for limb salvage.

    Sarcina, A; Carlesi, R; Bellosta, R; Agrifoglio, G

    1993-02-01

    A total of 130 infrapopliteal in situ saphenous vein bypasses were performed in 128 patients between January 1980 and June 1991. The indication for surgery was critical ischaemia with impending limb loss in 121 patients; seven suffered from severe claudication. The distal anastomosis was to the popliteal artery below the knee in 60 cases (46.2%) and in 70 (53.8%) to the tibioperoneal arteries. The results, in terms of secondary patency and limb salvage rates, of the first 68 procedures (1980-1985) and subsequent 62 (1986-June 1991) were compared. In the first period, a secondary patency rate of 42.6% and a limb salvage rate of 67.0% were obtained, compared with 71.3 and 80.8% respectively in the second. These differences are significant for patency (P < 0.005) and limb salvage (P < 0.01). These results show that the in situ technique can give acceptable results but a learning period with a high percentage of early failures is to be expected. PMID:8075993

  3. Cell-permeable succinate prodrugs bypass mitochondrial complex I deficiency.

    Ehinger, Johannes K; Piel, Sarah; Ford, Rhonan; Karlsson, Michael; Sjövall, Fredrik; Frostner, Eleonor Åsander; Morota, Saori; Taylor, Robert W; Turnbull, Doug M; Cornell, Clive; Moss, Steven J; Metzsch, Carsten; Hansson, Magnus J; Fliri, Hans; Elmér, Eskil

    2016-01-01

    Mitochondrial complex I (CI) deficiency is the most prevalent defect in the respiratory chain in paediatric mitochondrial disease. This heterogeneous group of diseases includes serious or fatal neurological presentations such as Leigh syndrome and there are very limited evidence-based treatment options available. Here we describe that cell membrane-permeable prodrugs of the complex II substrate succinate increase ATP-linked mitochondrial respiration in CI-deficient human blood cells, fibroblasts and heart fibres. Lactate accumulation in platelets due to rotenone-induced CI inhibition is reversed and rotenone-induced increase in lactate:pyruvate ratio in white blood cells is alleviated. Metabolomic analyses demonstrate delivery and metabolism of [(13)C]succinate. In Leigh syndrome patient fibroblasts, with a recessive NDUFS2 mutation, respiration and spare respiratory capacity are increased by prodrug administration. We conclude that prodrug-delivered succinate bypasses CI and supports electron transport, membrane potential and ATP production. This strategy offers a potential future therapy for metabolic decompensation due to mitochondrial CI dysfunction. PMID:27502960

  4. Novel TPP-riboswitch activators bypass metabolic enzyme dependency

    Mayer, Günter; Lünse, Christina; Suckling, Colin; Scott, Fraser

    2014-07-01

    Riboswitches are conserved regions within mRNA molecules that bind specific metabolites and regulate gene expression. TPP-riboswitches, which respond to thiamine pyrophosphate (TPP), are involved in the regulation of thiamine metabolism in numerous bacteria. As these regulatory RNAs are often modulating essential biosynthesis pathways they have become increasingly interesting as promising antibacterial targets. Here, we describe thiamine analogs containing a central 1,2,3-triazole group to induce repression of thiM-riboswitch dependent gene expression in different E. coli strains. Additionally, we show that compound activation is dependent on proteins involved in the metabolic pathways of thiamine uptake and synthesis. The most promising molecule, triazolethiamine (TT), shows concentration dependent reporter gene repression that is dependent on the presence of thiamine kinase ThiK, whereas the effect of pyrithiamine (PT), a known TPP-riboswitch modulator, is ThiK independent. We further show that this dependence can be bypassed by triazolethiamine-derivatives that bear phosphate-mimicking moieties. As triazolethiamine reveals superior activity compared to pyrithiamine, it represents a very promising starting point for developing novel antibacterial compounds that target TPP-riboswitches. Riboswitch-targeting compounds engage diverse endogenous mechanisms to attain in vivo activity. These findings are of importance for the understanding of compounds that require metabolic activation to achieve effective riboswitch modulation and they enable the design of novel compound generations that are independent of endogenous activation mechanisms.

  5. Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose.

    Kulika Chomvong

    Full Text Available The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP. However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose production. Here, we developed an alternative xylose utilization pathway that largely bypasses the PPP. In the new pathway, d-xylulose is converted to d-xylulose-1-phosphate, a novel metabolite to S. cerevisiae, which is then cleaved to glycolaldehyde and dihydroxyacetone phosphate. This synthetic pathway served as a platform for the biosynthesis of ethanol and ethylene glycol. The use of d-xylulose-1-phosphate as an entry point for xylose metabolism opens the way for optimizing chemical conversion of pentose sugars in S. cerevisiae in a modular fashion.

  6. Plasma levels of immunosuppressive mediators during cardiopulmonary bypass

    E. Borrelli

    1996-01-01

    Full Text Available The aim of this study was to evaluate plasma levels of two mediators with immunosuppressive properties, complement fraction C3a (C3a and transforming growth factor-β1 (TGF-β1, during extracorporeal circulation. The proliferation index after phytohaemagglutinin (PHA stimulation of isolated peripheral blood mononuclear cells was also investigated. Sixteen patients undergoing hypothermic (n = 8, group 1 and normothermic (n = 8, group 2 cardiopulmormry bypass (CPB were enrolled in this study. As a control, we evaluated four patients undergoing thoracovascular operations without CPB. Blood samples were collected before CPB but after anaesthesia, every 30 min during CPB, at the end of CPB and 10 min after protamine administration. Both C3a and TGF-β1 increased significantly during CPB and after protamine administration in the hypothermic as well as the normothermic group. In the latter case the increase of C3a and TGF-β1, although more prominent, was not significantl higher than in the former group. Conversely, the proliferation, index of peripheral mononuclear cells had already decreased 30 min after CPB was started and remained depressed throughout the CPB time. These results suggest a possible role of C3a and TGF-β1 in the immunological changes occurring during extracorporeal circulation.

  7. Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose

    Chomvong, Kulika; Bauer, Stefan; Benjamin, Daniel I.; Li, Xin; Nomura, Daniel K.; Cate, Jamie H. D.

    2016-01-01

    The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP). However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose production. Here, we developed an alternative xylose utilization pathway that largely bypasses the PPP. In the new pathway, d-xylulose is converted to d-xylulose-1-phosphate, a novel metabolite to S. cerevisiae, which is then cleaved to glycolaldehyde and dihydroxyacetone phosphate. This synthetic pathway served as a platform for the biosynthesis of ethanol and ethylene glycol. The use of d-xylulose-1-phosphate as an entry point for xylose metabolism opens the way for optimizing chemical conversion of pentose sugars in S. cerevisiae in a modular fashion. PMID:27336308

  8. DOES MEAN PERFUSION PRESSURE DURING CARDIOPULMONARY BYPASS AFFECT RENAL FUNCTION?

    Ramesh

    2015-10-01

    Full Text Available BACKGROUND: After cardiac surgery acute kidney injury (AKI is a common and serious condition carrying significant costs and is independently associated with increased morbidity and mortality. During cardiopulmonary bypass (CPB surgery, modifiable factors may contri bute to post - operative AKI. Their prevention might be a potential target for nephroprotection and any other morbidity after cardiac surgery. METHODS AND MATERIAL : The objective of the present study was to identify and determine whether intraoperative hypot ension or any other cofactor are independent risk factors for postoperative AKI defined by the RIFLE (renal Risk, Injury, Failure, Loss of renal function and End - stage renal disease. On basis of this patients were divided into two groups according to rise in serum creatinine >0.3 mg/dl till 72 hrs postoperatively. Group B patients have developed AKI (n=34 and the remaining patients were in Group A. RESULT : In our study we have found that mean arterial pressure during CPB were less in group B patients compare to group A patients which was statistically significant (p<0.001. And in this group ICU stay and mortality rate were also high compare to group A pati ent who had not developed AKI. CONCLUSION: Lower MAP during CPB is associated with development of postoperative renal derangement, leads to increase ICU stay and mortality. Larger studies are required to further support the evidence

  9. Coronary artery bypass surgery in the diabetic patient.

    Maher, M

    2012-02-03

    Coronary artery and peripheral occlusive arterial disease frequently complicate diabetes mellitus, with death due to atherosclerotic coronary artery disease being three times more likely in diabetic compared to non-diabetic patients. The profile of 32 diabetic patients and 32 matched controls who underwent coronary artery bypass (CABG) is studied and their early and late postoperative outcomes are described. The mean age was 61 +\\/- 1 year in both groups. The diabetic group comprised 26 non-insulin dependent and 6 insulin dependent diabetics, who had a mean duration of diabetes of 8.5 years (range 2 months--35 years). The median number of grafts per patient performed in the diabetic group and the control group was 3.5 and 3 respectively. There was no mortality in the series, however considerably greater wound morbidity rates were encountered in the diabetic group when compared to matched controls. One renal transplant patient in the diabetic group suffered irreversible acute tubular necrosis and became dialysis dependent post-operatively. Longterm follow-up showed no longterm mortality in either group, with full relief of angina achieved in 75% of diabetic patients compared with 87.5% of matched controls. In addition diabetic patients suffered greater longterm cardiac morbidity than the control group (21.8% versus 12.5%). The results of this study suggest that CABG is a safe operation for the diabetic patient. Diabetic patients receive satisfactory symptomatic relief of angina, but suffer increased perioperative wound complications and greater incidence of longterm cardiac morbidity.

  10. Hypothermia and normothermia effects on mortality rate of cardiopulmonary bypass

    Ali Rahdari

    2015-12-01

    Full Text Available Introduction: Cardiopulmonary bypass is associated with higher risk of mortality and morbidity, thus it should be investigated regarding the major risk factors. Temperature management have a significant role in postoperative cerebral and neurological complications; however the optimum temperature during cardiopulmonary surgery is not certainly detected. This systematic review has investigated the differences between hypothermia and normothermia regarding postoperative mortality. Method: PubMed was searched for the relevant articles. Only English language articles were included with no time limitation. Data regarding in-hospital patient deaths provided in each article mostly within 30 days after the surgery, were extracted and compared based on relative risk reduction (RRR, absolute risk reduction (ARR, and number needed to treat (NNT.Result: Totally, 28 articles were retrieved and extracted. The mortality rate was zero in hypothermic and normotehrmic groups of 8/28 included studies, thus the RRR, ARR, and NNT could not be calculated. There were no significant differences between investigated groups of each included studies regarding the patients’ age, gender, and preoperative conditions.Conclusions: No significant difference was obtained between two studied groups. Similar prevalence of death observed between hypothermic and normothermic groups might be due to the sample size of studies, or the subsequent cares performed in intensive care units that assist to reduce the postoperative mortality rate. According to the obtained results, both of these procedures might be similarly safe regarding mortality rate.

  11. Substance misuse following Roux-en-Y gastric bypass surgery.

    Reslan, Summar; Saules, Karen K; Greenwald, Mark K; Schuh, Leslie M

    2014-03-01

    Post-bariatric surgery patients are overrepresented in substance abuse treatment, particularly those who have had the Roux-en-Y gastric bypass (RYGB) procedure. The severity of the substance use disorder (SUD; i.e., warranting inpatient treatment) and related consequences necessitate a better understanding of the variables associated with post-RYGB SUDs. This investigation assessed factors associated with post-RYGB substance misuse. Post-RYGB patients (N = 141; at least 24 months postsurgery) completed an online survey assessing variables hypothesized to contribute to post-RYGB SUDs. Fourteen percent of participants met criteria for postoperative substance misuse. Those with a lower percent total weight loss (%TWL) were more likely to endorse substance misuse. Family history of substance misuse was strongly associated with postoperative substance misuse. Eating-related variables including presurgical food addiction and postsurgical nocturnal eating, subjective hunger, and environmental responsiveness to food cues were also associated with a probable postoperative SUD. These findings have clinical utility in that family history of substance misuse can be easily assessed, and at-risk patients can be advised accordingly. In addition, those who endorse post-RYGB substance misuse appear to have stronger cognitive and behavioral responses to food, providing some support for the theory of behavioral substitution (or "addiction transfer"). PMID:24102253

  12. Off-Pump Coronary Bypass Grafting Causing Stunned Myocardium

    Feridoun Sabzi

    2015-10-01

    Full Text Available The term “stunned myocardium” refers to abnormalities in the myocardial function following reperfusion and is common in on-pump coronary artery bypass grafting (CABG and is exceedingly rare in off- pump CABG. A 53-year-old man presented with unstable angina due to the severe stenosis of the left anterior descending coronary artery (LAD and the obtuse marginal. Laboratory findings and Chest X-ray revealed nothing abnormal. The intraoperative course was uneventful. The patient left the operating room without any inotropic support. Six hours later, however, he developed low cardiac output .At exploration, cardiac tamponade was excluded and flowmetry showed that the graft had adequate function. Cardiac enzymes were normal. High-dose adrenalin and Dobutamine were administrated and an intra-aortic balloon pump was used. After hemodynamic stabilization, the patient left the Intensive Care Unit without an intra-aortic balloon pump and inotropic support. On the fifth postoperative day, coronary angiography showed patent grafts and correct anastomotic sites. On the seventh postoperative day, the akinetic lateral wall of the left ventricle changed to dyskinesia. Finally after hospital discharge on the thirtieth postoperative day, an echocardiogram showed normal left ventricular function without regional wall motion abnormalities

  13. Magnetic navigation in patients with coronary artery bypass grafting.

    Ramcharitar, Steve; van Geuns, Robert-Jan

    2009-05-01

    Magnetic navigation (MN) can precisely control a percutaneous coronary interventions (PCI) guidewire or a device in three-dimensional space within the body without requiring reshaping of the tip to access vessels or areas of the heart that are often challenging using conventional wires. In this article we review and report on the use of magnetic navigation system in secondary revascularisation of coronary arterial bypass grafts (CABG). MN was successfully used in the secondary revascularisation of failed conventional CABG cases. Retrograde PCI through a LIMA is not only feasible but the wires can manage complex stenoses involving a bifurcation by using 3D reconstruction software. Difficult anatomies such as a hairpin bend as highlighted in this paper found at a saphenous vein graft (SVG) anastomosis can be overcome by co-integrating a CTCA 3D dataset for navigation. Preliminary data supports potential advantages in reduction of contrast media usage, crossing and fluoroscopy times and suggest that larger randomised studies are warranted. PMID:19736073

  14. Efficacy of Intravenous Acetaminophen after Coronary Artery Bypass Graft Surgery

    Leick AM

    2015-12-01

    Full Text Available In recent years, a multimodal approach to post-operative pain control consisting of opioid and non-opioid agents administered simultaneously has been used to provide synergistic effects and reduce opioid-related adverse effects. This is a retrospective, cohort study involving coronary artery bypass graft surgery patients who received scheduled intravenous IV acetaminophen 1gm every 6 hours for 4 doses starting at surgery end time with opioids administered as needed versus opioids as monotherapy for postoperative pain control. The primary endpoint assessed was total morphine equivalents administered post-operatively in each group with a secondary focus on degree of pain control, total length of stay, ICU length of stay, and time to first bowel movement. The study concludes that the addition of IV acetaminophen to opioids for postoperative pain relief did not produce an opioid sparing effect and paradoxically led to an increase in opioid use. Clinical outcomes including pain control, total length of stay, and ICU length of stay were unaffected by the addition of IV acetaminophen.

  15. Effects of graphite surface roughness on bypass flow computations for an HTGR

    Highlights: ► CFD calculations are made of bypass flow between graphite blocks in HTGR. ► Several turbulence models are employed to compare to friction and heat transfer correlations. ► Parameters varied include bypass gap width and surface roughness. ► Surface roughness causes increases in max fuel and coolant temperatures. ► Surface roughness does not cause increase in outlet coolant temperature variation. - Abstract: Bypass flow in a prismatic high temperature gas reactor (HTGR) occurs between graphite blocks as they sit side by side in the core. Bypass flow is not intentionally designed to occur in the reactor, but is present because of tolerances in manufacture, imperfect installation and expansion and shrinkage of the blocks from heating and irradiation. It is desired to increase the knowledge of the effects of such flow; it has been suggested that it may be as much as 20% of the total helium coolant flow [INL Report 2007, INL/EXT-07-13289]. Computational fluid dynamic (CFD) simulations can provide estimates of the scale and impacts of bypass flow. Previous CFD calculations have examined the effects of bypass gap width, level and distribution of heat generation and effects of shrinkage. The present contribution examines the effects of graphite surface roughness on the bypass flow for different relative roughness factors for three gap widths. Such calculations should be validated using specific bypass flow measurements. While such experiments are currently underway for the specific reference prismatic HTGR design for the next generation nuclear plant (NGNP) program of the U.S. Dept. of Energy, the data are not yet available. To enhance confidence in the present calculations, wall shear stress and heat transfer results for several turbulence models and their associated wall treatments are first compared for steady flow in a single tube that is representative of a coolant channel in the prismatic HTGR core. The results are compared to published

  16. Effects of Cardiopulmonary Bypass on Mediastinal Drainage and the Use of Blood Products in the Intensive Care Unit in 60- to 80-Year-Old Patients Who Have Undergone Coronary Artery Bypass Grafting

    Fatih Aygün; Mehmet Özülkü; Murat Günday

    2015-01-01

    ABSTRACT OBJECTIVE: The present study consisted of patients who underwent on-pump coronary artery bypass grafting (CABG) and off-pump CABG and investigated effect of using cardiopulmonary bypass (CPB) on the amount of postoperative drainage and blood products, red blood cell (RBC), free frozen plasma (FFP) given in the intensive care unit in 60-80-year-old patients who underwent CABG. METHODS: The present study comprises a total of 174 patients who have undergone coronary artery bypass graf...

  17. Weight Loss After Laparoscopic Band-to-Bypass Revision Compared With Primary Gastric Bypass: Long-term Outcomes.

    Sadot, Eran; Spivak, Hadar

    2015-06-01

    Laparoscopic Roux-en-Y gastric bypass (RYGB) is frequently performed as a salvage operation after failed laparoscopic adjustable gastric banding (LAGB). Reports about long-term outcomes are lacking. We assessed the long-term outcomes of RYGB revision surgery after failed LAGB (study group, n = 44) and compared these outcomes with a demographically matched group who underwent primary RYGB (control group, n = 82). There were no between-group differences in sex distribution, age, or initial weight characteristics. At 2 years after RYGB, the mean ΔBMI was 11.8 ± 5.7 kg/m2 in the study group and 15.6 ± 4.2 kg/m2 in the control group (P = 0.01); the corresponding %EWL values were 57% and 78% (P = 0.005). At 6 years after RYGB, the mean ΔBMI was 10 ± 4.5 kg/m2 in the study group and 13.6 ± 5.7 kg/m2 in the control group (P = 0.006); the corresponding %EWL values were 53% and 66% (P = 0.04). In conclusion, this study supports the safety and favorable weight-loss outcome of LAGB revision to RYGB. However, the results are inferior to those of primary RYGB. PMID:25856132

  18. Effect of utilization of veno-venous bypass vs. cardiopulmonary bypass on complications for high level inferior vena cava tumor thrombectomy and concomitant radical nephrectomy

    Ross M. Simon

    2015-10-01

    Full Text Available ABSTRACT Purpose: To determine if patients with renal cell carcinoma (RCC with levels III and IV tumor thrombi are receive any reduction in complication rate utilizing veno-venous bypass (VVB over cardiopulmonary bypass (CPB for high level (III/IV inferior vena cava (IVC tumor thrombectomy and concomitant radical nephrectomy. Materials and Methods: From May 1990 to August 2011, we reviewed 21 patients that had been treated for RCC with radical nephrectomy and concomitant IVC thrombectomy employing either CPB (n =16 or VVB (n=5. We retrospectively reviewed our study population for complication rates and perioperative characteristics. Results: Our results are reported using the validated Dindo-Clavien Classification system comparing the VVB and CPB cohorts. No significant difference was noted in minor complication rate (60.0% versus 68.7%, P=1.0, major complication rate (40.0% versus 31.3%, P=1.0, or overall complication rate (60.0% versus 62.5%, P=1.0 comparing VVB versus CPB. We also demonstrated a trend towards decreased time on bypass (P=0.09 in the VVB cohort. Conclusion: The use of VVB over CPB provides no decrease in minor, major, or overall complication rate. The use of VVB however, can be employed on an individualized basis with final decision on vascular bypass selection left to the discretion of the surgeon based on specifics of the individual case.

  19. A case report and brief review of the literature on bilateral retinal infarction following cardiopulmonary bypass for coronary artery bypass grafting

    Trethowan Brian A

    2011-11-01

    Full Text Available Abstract Postoperative visual loss is a devastating perioperative complication. The commonest aetiologies are anterior ischaemic optic neuropathy (AION, posterior ischaemic optic neuropathy (PION, and central retinal artery occlusion (CRAO. These appear to be related to certain types of operation, most commonly spinal and cardiac bypass procedures; with the rest divided between: major trauma causing excessive blood loss; head/neck and nasal or sinus surgery; major vascular procedures (aortic aneurysm repair, aorto-bifemoral bypass; general surgery; urology; gynaecology; liposuction; liver transplantation and duration of surgery. The non-surgical risk factors are multifactorial: advanced age, prolonged postoperative anaemia, positioning (supine v prone, alteration of venous drainage of the retina, hypertension, smoking, atherosclerosis, hyperlipidaemia, diabetes, hypercoagulability, hypotension, blood loss and large volume resuscitation. Other important cardiac causes are septic emboli from bacterial endocarditis and emboli caused by atrial myxomata. The majority of AION cases occur during CPB followed by head/neck surgery and prone spine surgery. CPB is used to allow coronary artery bypass grafting on a motionless heart. It has many side-effects and complications associated with its use and we report here a case of bilateral retinal infarction during routine coronary artery bypass grafting in a young male patient with multiple risk factors for developing this complication despite steps to minimise its occurrence.

  20. Evaluation of early coronary graft patency after coronary artery bypass graft surgery using multislice computed tomography angiography

    Raissi Kamal; Givtaj Nader; Abdi Seifollah; Motevali Marzieh; Noohi Fereidoun; Salari Farzad; Bassri Hosseinali; Haghjoo Majid

    2009-01-01

    Abstract Background Coronary artery bypass graft (CABG) surgery is the standard of care in the treatment of advanced coronary artery disease, and its long-term results are affected by the failure of bypass grafts. The aim of the present study was to evaluate the early patency rate in coronary bypass grafts. Methods A total of 107 consecutive patients who underwent CABG were included in this study. Early graft patency was evaluated via computed tomography (CT) angiography in the first week aft...

  1. Aorta-LITA Bypass Grafting with Saphenous Vein in a Patient Undergoing Coronary Artery Surgery with Subclavian Artery Stenosis

    Kerim Çağlı

    2011-12-01

    Full Text Available The internal thoracic artery (ITA is the primary graft for coronary artery bypass grafting and can not be used if there is subclavian artery stenosis (SAS. Aorto-axillary, carotid-subclavian bypass and also angioplasty with stenting or other interventional treatments are acceptable procedures for SAS treatment. Aorta-ITA bypass with saphenous vein can be alternative and simple technique for SAS to save Winslow pathway for patients with peripheral artery disease.

  2. Changes in fetal ovine metabolism and oxygen delivery with fetal bypass.

    Lam, Christopher T; Baker, R Scott; Clark, Kenneth E; Eghtesady, Pirooz

    2011-07-01

    Since the 1980s, attempts at experimental fetal cardiac bypass for the purpose of correcting severe congenital heart defects in the womb have been hampered by deterioration of placental function. This placental pathophysiology in turn affects transplacental transport of nutrients and gas exchange. To date, the effects of bypass on fetal metabolism and oxygen delivery have not been studied. Nine Suffolk sheep fetuses from 109-121 days gestation were instrumented and placed on fetal bypass for 30 min and followed postbypass for 2 h. Blood gases, glucose, and lactate were serially measured in the fetal arterial and umbilical venous circulations throughout the procedure. Insulin and glucagon levels were serially measured by immunoassay in fetal plasma. Fetal-placental hemodynamics were measured continuously. The expression of glycogen content was examined in fetal liver. Oxygen delivery to the fetus and fetal oxygen consumption were significantly deranged after the conduct of bypass (in-group ANOVA (P = 0.001) and overall contrast (P = 0.072) with planned contrast (P < 0.05) for delivery and consumption, respectively). There were significant alterations in fetal glucose metabolism in the postbypass period; however, insulin and glucagon levels did not change. Fetal liver glycogen content appeared lower after bypass. This is the first report documenting fetal metabolic dysregulation that occurs in response to the conduct of fetal bypass. The significant alterations in fetal oxygen and glucose delivery coupled with hepatic glycogen depletion complicate and impede fetal recovery. These initial findings warrant further investigation of interventions to restore metabolic and hemodynamic homeostasis after fetal bypass. PMID:21508289

  3. Improved red blood cell survival after cardiac operations with administration of urea during cardiopulmonary bypass

    The plasma hemoglobin and red blood cell survival (half-life of 51Cr) was studied in 48 patients undergoing single valve replacement or coronary artery bypass graft. Urea or placebo was administered during cardiopulmonary bypass in a prospective, randomized, double-blind manner to test the potential effect on mechanical hemolysis. The mean plasma hemoglobin level at the end of extracorporeal circulation was significantly lower in the urea-treated groups (coronary artery bypass 342 mg/L; valve replacement 364 mg/L) than in the control groups (coronary artery bypass 635 mg/L, valve replacement 518 mg/L. The half-life of 51Cr was significantly longer in the urea-treated patients (coronary artery bypass 18 days; valve replacement 16 days) than in the control groups (coronary artery bypass 12.4 days; valve replacement 12.7 days) but still below the normal reference value (29 +/- 4 days). The plasma hemoglobin returned to near normal values (50 mg/L) the day after operation (day 1) and remained low with no differences between control and urea-treated groups. The total blood hemoglobin was followed for 2 weeks after operation and showed significantly less anemia in the urea-treated group. The lowest mean blood hemoglobin level was noted between days 5 and 9-114 (coronary artery bypass) and 107 (valve replacement) gm/L in the urea-treated patients compared to 92.3 gm/L in the control subjects. The reduction in the severity of the anemia led to less transfusion in the urea-treated patients (approximately 0.5 unit/patient) than in the control subjects (approximately 1 unit/patient) between days 3 and 14

  4. EC-IC bypass for cavernous carotid aneurysms: An initial experience with twelve patients

    Menon, G.; Jayanand, Sudhir; Krishnakumar, K.; Nair, S.

    2014-01-01

    Aims: Need for performing a bypass procedure prior to parent artery occlusion in patients with good cerebral vascular reserve is controversial. We analyze our experience of 12 giant internal carotid artery aneurysms treated with extracranial-intracranial (EC-IC) bypass and proximal artery occlusion. Materials and Methods: Retrospective analysis of the case records of all complex carotid aneurysms operated in our institute since January 2009. Results: The study included eleven cavernous carotid aneurysms and one large fusiform cervical carotid aneurysm reaching the skull base. Preoperative assessment of cerebral vascular reserve was limited to Balloon test occlusion with hypotensive challenge. Eleven patients who successfully completed a Balloon test occlusion (BTO) underwent low flow superficial temporal artery to middle cerebral artery (STA-MCA) bypass, while one patient with a failed BTO underwent a high flow bypass using a saphenous vein graft. Parent artery ligation was performed in all patients following the bypass procedure. Check angiogram revealed thrombosis of the aneurysm in all patients with a graft patency rate of 81.8%. We had one operative mortality, probably related to a leak from the anastomotic site. The only patient who had a high flow bypass developed contralateral hemispheric infarcts and remained vegetative. All the other patients had a good recovery and with a Glasgow outcome score of 5 at last follow-up. Conclusion: We feel that combining EC-IC bypass prior to parent vessel occlusion helps in reducing the risk of post operative ischemic complications especially in situations where a complete mandated cerebral blood flow studies are not feasible. PMID:25126123

  5. Neurodevelopmental outcome after cardiac surgery utilizing cardiopulmonary bypass in children

    Aymen N Naguib

    2015-01-01

    Full Text Available Introduction: Modulating the stress response and perioperative factors can have a paramount impact on the neurodevelopmental outcome of infants who undergo cardiac surgery utilizing cardiopulmonary bypass. Materials and Methods: In this single center prospective follow-up study, we evaluated the impact of three different anesthetic techniques on the neurodevelopmental outcomes of 19 children who previously underwent congenital cardiac surgery within their 1 st year of life. Cases were done from May 2011 to December 2013. Children were assessed using the Stanford-Binet Intelligence Scales (5 th edition. Multiple regression analysis was used to test different parental and perioperative factors that could significantly predict the different neurodevelopmental outcomes in the entire cohort of patients. Results: When comparing the three groups regarding the major cognitive scores, a high-dose fentanyl (HDF patients scored significantly higher than the low-dose fentanyl (LDF + dexmedetomidine (DEX (LDF + DEX group in the quantitative reasoning scores (106 ± 22 vs. 82 ± 15 P = 0.046. The bispectral index (BIS value at the end of surgery for the -LDF group was significantly higher than that in LDF + DEX group (P = 0.011. For the entire cohort, a strong correlation was seen between the standard verbal intelligence quotient (IQ score and the baseline adrenocorticotropic hormone level, the interleukin-6 level at the end of surgery and the BIS value at the end of the procedure with an R 2 value of 0.67 and P < 0.04. There was an inverse correlation between the cardiac Intensive Care Unit length of stay and the full-scale IQ score (R = 0.4675 and P 0.027. Conclusions: Patients in the HDF group demonstrated overall higher neurodevelopmental scores, although it did not reach statistical significance except in fluid reasoning scores. Our results may point to a possible correlation between blunting the stress response and improvement of the neurodevelopmental

  6. Strategies to prevent intraoperative lung injury during cardiopulmonary bypass

    Siminelakis Stavros N

    2010-01-01

    Full Text Available Abstract During open heart surgery the influence of a series of factors such as cardiopulmonary bypass (CPB, hypothermia, operation and anaesthesia, as well as medication and transfusion can cause a diffuse trauma in the lungs. This injury leads mostly to a postoperative interstitial pulmonary oedema and abnormal gas exchange. Substantial improvements in all of the above mentioned factors may lead to a better lung function postoperatively. By avoiding CPB, reducing its time, or by minimizing the extracorporeal surface area with the use of miniaturized circuits of CPB, beneficial effects on lung function are reported. In addition, replacement of circuit surface with biocompatible surfaces like heparin-coated, and material-independent sources of blood activation, a better postoperative lung function is observed. Meticulous myocardial protection by using hypothermia and cardioplegia methods during ischemia and reperfusion remain one of the cornerstones of postoperative lung function. The partial restoration of pulmonary artery perfusion during CPB possibly contributes to prevent pulmonary ischemia and lung dysfunction. Using medication such as corticosteroids and aprotinin, which protect the lungs during CPB, and leukocyte depletion filters for operations expected to exceed 90 minutes in CPB-time appear to be protective against the toxic impact of CPB in the lungs. The newer methods of ultrafiltration used to scavenge pro-inflammatory factors seem to be protective for the lung function. In a similar way, reducing the use of cardiotomy suction device, as well as the contact-time between free blood and pericardium, it is expected that the postoperative lung function will be improved.

  7. [Results of splenorenal venous bypass grafting in patients with hepatocirrhosis].

    Katel'nitskiĭ, I I; Sapronova, N G

    2013-01-01

    Presented herein are the results of surgical treatment of 79 patients with intrahepatic portal hypertension who underwent splenorenal venous bypass grafting after splenectomy. The patients' age varied from 8 to 64 years, averaging 37.3 years. The authors followed up the immediate and remote results of treatment at terms varying from 1 to 20 years. Of the early postoperative complications mention should be made that intra-abdominal haemorrhage was revealed in 4 (5%) patients, six (7.6%) patients were found to develop left-side reactive pleuritis, one patient (1.2%) - bilateral pleuritis and pericarditis, subcutaneous eventration was revealed in 1 patient with pronounced ascites (1.2%). Haemorrhage from varicose dilated oesophageal veins in the early postoperative period was observed in 8 (10%) cases. Posthaemorrhagic anaemia was present in 27 cases (43.1%). The mortality rate in the early postoperative period amounted to 5% (4). We followed up the long-term results in 51 (64.5%) of the 79 patients at terms up to 5 years after surgery, in 17 patients at terms up to 10 years following interventions, in 9 at terms up to 15 years, and in one patient up to 20 years. A total of 3 patients died within the first postoperative year. 48 (94%) patients are alive 5 years after the operation, 10 - after ten years, with 7 having died. Five patients are still alive more than 15 years, four died, one followed up woman is still alive after 20 years with a satisfactory result. PMID:23863796

  8. Hyperhomocysteinemia and mortality after coronary artery bypass grafting.

    Domenico Girelli

    Full Text Available BACKGROUND: The independent prognostic impact, as well as the possible causal role, of hyperhomocysteinemia (HHcy in coronary artery disease (CAD is controversial. No previous study specifically has addressed the relationship between HHcy and mortality after coronary artery bypass grafting (CABG surgery. The aim of this study is to evaluate the prognostic impact of HHcy after CABG surgery. METHODOLOGY AND PRINCIPAL FINDINGS: We prospectively followed 350 patients who underwent elective CABG between May 1996 and May 1999. At baseline, fasting total homocysteine (tHcy levels were measured in all participants, and a post-methionine loading (PML test was performed in 77.7% of them (n = 272. After a median follow-up of 58 months, 33 patients (9.4% had died, 25 because of cardiovascular events. HHcy, defined by levels higher than the 90th percentile (25.2 micromol/L of the population's distribution, was significantly associated to total and cardiovascular mortality (P = 0.018 [log-rank test 5.57]; P = 0.002 [log-rank test 9.76], respectively. The PML test had no prognostic value. After multiple adjustment for other univariate predictors by Cox regression, including statin therapy (the most powerful predictor in uni-/multivariate analyses, high-sensitivity C Reactive Protein (hs-CRP levels, and all known major genetic (MTHFR 677C-->T polymorphism and non-genetic (B-group vitamin status and renal function tHcy determinants, HHcy remained an independent prognostic factor for mortality (HRs: 5.02, 95% CIs 1.88 to 13.42, P = 0.001. CONCLUSIONS: HHcy is an important prognostic marker after CABG, independent of modern drug therapy and biomarkers.

  9. Investigation on the Core Bypass Flow in a Very High Temperature Reactor

    Hassan, Yassin

    2013-10-22

    Uncertainties associated with the core bypass flow are some of the key issues that directly influence the coolant mass flow distribution and magnitude, and thus the operational core temperature profiles, in the very high-temperature reactor (VHTR). Designers will attempt to configure the core geometry so the core cooling flow rate magnitude and distribution conform to the design values. The objective of this project is to study the bypass flow both experimentally and computationally. Researchers will develop experimental data using state-of-the-art particle image velocimetry in a small test facility. The team will attempt to obtain full field temperature distribution using racks of thermocouples. The experimental data are intended to benchmark computational fluid dynamics (CFD) codes by providing detailed information. These experimental data are urgently needed for validation of the CFD codes. The following are the project tasks: • Construct a small-scale bench-top experiment to resemble the bypass flow between the graphite blocks, varying parameters to address their impact on bypass flow. Wall roughness of the graphite block walls, spacing between the blocks, and temperature of the blocks are some of the parameters to be tested. • Perform CFD to evaluate pre- and post-test calculations and turbulence models, including sensitivity studies to achieve high accuracy. • Develop the state-of-the art large eddy simulation (LES) using appropriate subgrid modeling. • Develop models to be used in systems thermal hydraulics codes to account and estimate the bypass flows. These computer programs include, among others, RELAP3D, MELCOR, GAMMA, and GAS-NET. Actual core bypass flow rate may vary considerably from the design value. Although the uncertainty of the bypass flow rate is not known, some sources have stated that the bypass flow rates in the Fort St. Vrain reactor were between 8 and 25 percent of the total reactor mass flow rate. If bypass flow rates are on the

  10. CPAP of 10 cmH2O during cardiopulmonary bypass followed by an alveolar recruitment manoeuvre does not improve post-bypass oxygenation compared to a recruitment manoeuvre alone in children.

    Kim, J T; Na, H S; Kim, H S; Kim, C S; Kim, S D

    2010-03-01

    This randomised controlled study assessed whether continuous positive airway pressure (CPAP) of 10 cmH2O during cardiopulmonary bypass improves post-bypass oxygenation in children compared with no CPAP during bypass. We studied children with a ventricular septal defect. CPAP of 10 cmH2O was applied during bypass in the CPAP group (n=24), whereas the lungs were left deflated in the control group (n=20). In both groups, an alveolar recruitment maneuver was performed by applying positive pressure of 30 to 40 cmH2O for five seconds before weaning from bypass. Postoperative ventilation had the peak inflation pressure set to produce an expired tidal volume of 8 ml/kg with positive end expiratory pressure of 5 cmH2O. Arterial blood gas and haemodynamic measurements were performed at skin incision, five minutes after weaning from bypass, five minutes after chest closure and four hours after arrival in the intensive care unit. In four children CPAP was discontinued because it adversely affected the operating field. There was no difference in demographic characteristics, haemodynamic data, bypass time and operation time. No difference was observed between the groups with respect to pH, PaO2, P(A-a) DO2, PaCO2, and ETCO2 at each time. Variability in the data was greater than expected, leading to a decrease in the expected power of the study. CPAP at 10 cmH2O during bypass was not found to improve the post-bypass oxygenation as compared with leaving the lung deflated during bypass in children undergoing ventricular septal defect repair who had an alveolar recruitment maneuver at the end of bypass. PMID:20369762

  11. The role of extra- and intracranial bypass in the treatment of complex aneurysms.

    Cenzato, Marco; Bortolotti, Carlo

    2016-03-01

    The availability of flow diverters and new endovascular techniques has greatly reduced the need and indications for bypass surgery. Nevertheless, there are situations where a bypass is the best option for a complex cerebrovascular problem. Generally, typical indications are giant aneurysms with a wide neck and/or partially calcified aneurysms with main branches or perforating arteries arising directly from the sac or from the neck itself, or fusiform aneurysms, partially calcified aneurysms. In this paper we discuss the following issues as they apply to the modern use of bypass techniques. In case of fusiform aneurysms involving the proximal bifurcations of the media or the internal carotid artery combined and coordinated evaluations and efforts by a team which includes neurosurgeons and endovascular specialists is essential. Treatment with bypass alone may not be sufficient and the combination of one or more bypasses with an endovascular treatment of occlusion, partial aneurysm embolization or flow diversion may be the best strategy. Addressing complex and fusiform aneurysm surgery requires a problem solving attitude and in this lies both the challenging and the fun side of this surgery. PMID:26947783

  12. Bypasses of the antimycin a block of mitochondrial electron transport in relation to ubisemiquinone function.

    Alexandre, A; Lehninger, A L

    1984-10-26

    Two different bypasses around the antimycin block of electron transport from succinate to cytochrome c via the ubiquinol-cytochrome c oxidoreductase of intact rat liver mitochondria were analyzed, one promoted by N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) and the other by 2,6-dichlorophenolindophenol (DCIP). Both bypasses are inhibited by myxothiazol, which blocks electron flow from ubiquinol to the Rieske iron-sulfur center, and by 2-hydroxy-3-undecyl-1,4-naphthoquinone, which inhibits electron flow from the iron-sulfur center to cytochrome c1. In the bypass promoted by TMPD its oxidized form (Wurster's blue) acts as an electron acceptor from some reduced component prior to the antimycin block, which by exclusion of other possibilities is ubisemiquinone. In the DCIP bypass its reduced form acts as an electron donor, by reducing ubisemiquinone to ubiquinol; reduced DCIP is regenerated again at the expense of either succinate or ascorbate. The observations described are consistent with and support current models of the Q cycle. Bypasses promoted by artificial electron carriers provide an independent approach to analysis of electron flow through ubiquinol-cytochrome c oxidoreductase. PMID:6091750

  13. Laparoscopic Revision of an Omega Loop Gastric Bypass to Treat Afferent Loop Syndrome.

    Kassir, Radwan; Blanc, Pierre; Lointier, Patrice; Breton, Christophe; Debs, Tarek; Tiffet, Olivier

    2015-10-01

    The omega loop gastric bypass (OLGB) has become a very commonly performed bariatric procedure because of the advantages it carries over the Roux en Y gastric bypass (RYGBP). However, mini gastric bypass is a misnomer, as this procedure is more malabsorptive than the RYGBP. Recently, it is called single or one anastomosis gastric bypass. The omega loop procedure is associated with a risk of afferent loop syndrome, a known complication of the Billroth II (Finsterer) operation. This rare complication of the OLGB can be debilitating, serious, and deadly. Afferent loop syndrome should be suspected in case of malabsorption syndrome with chronic diarrhea, steatorrhea, iron-deficiency anemia, edema, emaciation, and osteomalacia and also in case of simple biological anomalies such as macrocytosis or megaloblastic anemia. The diagnosis can be confirmed by measuring bacterial overgrowth, although this requires a jejunal aspirate performed during endoscopy with jejunal intubation. A microbial population of more than 106 organisms per milliliter of aspirate is pathological. Afferent loop syndrome is encountered less frequently now that the number of gastrectomies has dropped. Yet, with the omega loop bypass procedure becoming more common, surgeons must again be made aware of this potential complication. PMID:26210192

  14. Evolution of elderly patients who underwent cardiac surgery with cardiopulmonary bypass

    Alain Moré Duarte

    2016-01-01

    Full Text Available Introduction: There is a steady increase in the number of elderly patients with severe cardiovascular diseases who require a surgical procedure to recover some quality of life that allows them a socially meaningful existence, despite the risks.Objectives: To analyze the behavior of elderly patients who underwent cardiac surgery with cardiopulmonary bypass.Method: A descriptive, retrospective, cross-sectional study was conducted with patients over 65 years of age who underwent surgery at the Cardiocentro Ernesto Che Guevara, in Santa Clara, from January 2013 to March 2014.Results: In the study, 73.1% of patients were men; and there was a predominance of subjects between 65 and 70 years of age, accounting for 67.3%. Coronary artery bypass graft was the most prevalent type of surgery and had the longest cardiopulmonary bypass times. Hypertension was present in 98.1% of patients. The most frequent postoperative complications were renal dysfunction and severe low cardiac output, with 44.2% and 34.6% respectively.Conclusions: There was a predominance of men, the age group of 65 to 70 years, hypertension, and patients who underwent coronary artery bypass graft with prolonged cardiopulmonary bypass. Renal dysfunction was the most frequent complication.

  15. Crural Bypass for Critical Lower Limb Ischemia with Omniflow II Prosthesis.

    Dünschede, Friedrich; Stabrauskaite, Justina; Weisser, Gerhard; Espinola-Klein, Christine; Dorweiler, Bernhard; Vahl, Christian-Friedrich

    2016-06-01

    Background Reports about the use of the Omniflow II prosthesis (Bio Nova International, Victoria, Australia) in a crural position in patients with critical lower limb ischemia are rare. Methods All crural bypass operations were registered in a database. Primary end points of the study were amputation-free survival, limb salvage, and long-term patency. Results From January 2007 to December 2012, we implanted 27 Omniflow II prostheses in the crural position for critical lower limb ischemia. Of these, 12 crural bypasses were conducted with adjuvant distal arteriovenous fistula as a means to increase bypass flow in the presence of severely impaired intraoperative runoff or revision for early failure. Fifteen Omniflow II prosthesis bypasses were performed in the crural position without fistula. Overall, two patients died postoperatively. The limb salvage rate was 92% in the fistula group compared with 60% in the nonfistula group after a median observation time of 19 months in patients getting Omniflow prosthesis bypasses. Conclusion Omniflow II prosthesis in patients with critical lower limb ischemia and absence of sufficient autologous vein is durable. Moreover, the use of adjuvant distal arteriovenous fistula may increase the chance of limb salvage in this group of patients. PMID:26291743

  16. Early Coronary Artery Bypass Grafting Following Life-Saving Percutaneous Coronary Intervention

    Kerem Yay

    2013-10-01

    Full Text Available Aim: Percutaneous coronary intervention is usually the initial treatment option for treatment of emergent and severe coronary atherosclerosis with suitable coronary arteries. We aimed to investigate the clinical features, morbidity and mortality rates of coronary artery bypass grafting performed following life-saving stent procedures and patency rates of these stents. Material and Method: Between January 2005 and December 2008, we performed coronary artery bypass grafting on 23 patients who had previous percutaneous coronary intervention to the culprit artery for acute myocardial infarction. Early postoperative coronary angiography was obtained for evaluation of stent patency. Results: In-hospital mortality occurred in five patients (21.7%. Coronary angiographic examination of the remaining patients revealed severe stenosis or occlusion at 16 out 20 stents (80%. The mean time interval between percutaneous coronary intervention and coronary artery bypass grafting was found to be statistically significant regarding stent patency (p=0.007. Discussion: Bypass grafting to a previously stented coronary artery may be the relevant approach even if the angiographic findings are normal, because intraoperative manipulation and systemic effects of cardiopulmonary bypass if used will result in deformity or occlusion of the stent.

  17. Superficial temporal artery to proximal posterior cerebral artery bypass through the anterior temporal approach

    Satoru Takeuchi

    2015-01-01

    Full Text Available Background: The superficial temporal artery (STA to proximal posterior cerebral artery (PCA (P2 segment bypass is one of the most difficult procedures to perform because the proximal PCA is located deep and high within the ambient cistern. STA to proximal PCA bypass is usually performed through a subtemporal approach or posterior transpetrosal approach, and rarely through a transsylvian approach. The aim of this study was to describe the operative technique of STA to proximal PCA bypass through a modified transsylvian approach (anterior temporal approach. Methods: STA to proximal PCA bypass was performed through an anterior temporal approach in three patients with intracranial aneurysm. We describe the details of the surgical technique. Results: The STA was successfully anastomosed to the proximal PCA in all cases. One patient suffered hemiparesis and aphasia due to infarction in the anterior thalamoperforating artery territory. Conclusions: STA to proximal PCA bypass can be performed through an anterior temporal approach in selected patients. We recommend that every precaution, including complete hemostasis, placement of cellulose sponges beneath the recipient artery to elevate the site of the anastomosis, and placement of a continuous drainage tube at the bottom of the operative field to avoid blood contamination during the anastomosis, should be taken to shorten the temporary occlusion time.

  18. Experimental and analytic study on the core bypass flow in a very high temperature reactor

    Kim, Min Hwan; Lim, Hong Sik; Tak, Nam Il; Jun, Ji Su; Kim, Chan Soo; Yun, Churl; Jo, Chang Keun; Lee, Won Jae [KAERI, Daejeon (Korea, Republic of)

    2011-12-15

    A multi-block and multi-layer bypass flow test facility was designed and constructed. Experiments using the facility were carried out for uniform and non-uniform gap distributions of test blocks to produce data for the validation of codes. Using independent models developed for GAMMA+ code in Korea and GAS-NET code in the US, analyses for the bypass experiment were performed and the results were compared. In addition, CFD benchmark calculations by using CFX code in Korea and STARCCM+ in the US were carried out for MIR experiments and the validity of CFD models were assessed. A model for the estimation of bypass flow gap size in VHTR core was developed. And three dimensional core thermo-fluid analysis model considering the bypass gap distribution was developed by using the GAMMA+ code, which was applied to a prismatic core, developed in nuclear hydrogen project in KAERI, to predict core flow distribution and maximum fuel temperature. Finally, two measures of bypass flow reduction were suggested and their performance was assessed by the experiment.

  19. Separation of craniopagus Siamese twins using cardiopulmonary bypass and hypothermic circulatory arrest.

    Cameron, D E; Reitz, B A; Carson, B S; Long, D M; Dufresne, C R; Vander Kolk, C A; Maxwell, L G; Tilghman, D M; Nichols, D G; Wetzel, R C

    1989-11-01

    Occipitally joined craniopagus Siamese twins were separated with the use of cardiopulmonary bypass and hypothermic circulatory arrest. The 7-month-old infants shared a large sagittal venous sinus that precluded conventional neurosurgical approach because of risk of exsanguination and air embolism. After craniotomy and preliminary exposure of the sinus, each twin underwent sternotomy and total cardiopulmonary bypass with deep hypothermia. Hypothermic circulatory arrest allowed safe division and subsequent reconstruction of the sinus remnants. Several unusual problems were encountered, including transfusion of a large blood volume from one extracorporeal circuit to the other through the common venous sinus, deleterious warming of the exposed brain during circulatory arrest, and thrombosis of both pump oxygenators. Both infants survived, although recovery was complicated in each by neurologic injury, cranial wound infection, and hydrocephalus. This case demonstrates the valuable supportive role of cardiopulmonary bypass and hypothermic circulatory arrest in the management of complex surgical problems of otherwise inoperable patients. PMID:2682024

  20. Copper Deficiency after Gastric Bypass for Morbid Obesity: a Systematic Review.

    Kumar, Parveen; Hamza, Numan; Madhok, Brijesh; De Alwis, Nimantha; Sharma, Manisha; Miras, Alexander Dimitri; Mahawar, Kamal K

    2016-06-01

    A large number of patients undergoing bariatric surgery are deficient in copper, and Roux-en-Y gastric bypass can further aggravate it. Delays in diagnosis and treatment of copper deficiency can leave patients with residual neurological disability. This has led to recommendation from the British Obesity and Metabolic Surgery Society that copper levels should be monitored annually after gastric bypass. This review concludes that copper deficiency in adequately supplemented patients is rare and can be adequately treated if a related haematological or neurological disorder is diagnosed. The cost of routine monitoring may therefore not be justified for adequately supplemented, asymptomatic patients who have undergone Roux-en-Y gastric bypass. The screening may however be necessary for high-risk patient groups to prevent severe complications and permanent disability. PMID:27034062

  1. The influence of stenosis degrees and graft suture position on local hemodynamics of coronary bypass

    Totorean, A. F.; Bernad, S. I.; Susan-Resiga, R. F.

    2016-06-01

    Bypass graft failure is mainly caused by intimal hyperplasia (IH) that occurs at the graft anastomosis after coronary artery bypass grafting (CABG) surgery. It has been shown that local hemodynamics influences the process of IH initiation and progression. A main concern at this type of surgery is to increase the graft patency, respectively to improve the local hemodynamics. This paper analyzes the influence of different degree of stenosis severity and graft suture position on graft patency, taking into consideration the local hemodynamics. Bypass configurations with anastomosis angle of 45° were numerically investigated, with respect to wall shear stress and pressure variation. We can assume that in the conditions of our study, different stenosis degrees and position of the graft suture influence the local blood flow conditions, and, nevertheless, the graft patency.

  2. Redox-mediated bypass of restriction point via skipping of G1pm

    Greene James J

    2006-07-01

    Full Text Available Abstract Background It is well known that cancer cells bypass the restriction point, R, and undergo uncontrolled cell proliferation. Hypothesis and evidence We suggest here that fibrosarcoma cells enter G1ps directly from M, skipping G1pm, hence bypassing R, in response to redox modulation. Evidence is presented from the published literature that demonstrate a shortening of the cycle period of transformed fibroblasts (SV-3T3 compared to the nontransformed 3T3 fibroblasts, corresponding to the duration of G1pm in the 3T3 fibroblasts. Evidence is also presented that demonstrate that redox modulation can induce the CUA-4 fibroblasts to bypass R, resulting in a cycle period closely corresponding to the cycle period of fibrosarcoma cells (HT1080. Conclusion The evidence supports our hypothesis that a low internal redox potential can cause fibrosarcoma cells to skip the G1pm phase of the cell cycle.

  3. Determination of required delay time following reactor shutdown prior to actuation of LOFT ECCS Bypass

    Carmichael, C.F.

    1977-04-22

    The results of calculations are presented for the decay time required prior to LOFT ECCS shutdown bypass actuation following a reactor shutdown. These calculations are based on a LOCA occurring during hot shutdown which would void the core. Based on an operator response time of 20 minutes to manually establish ECC flow, the reactor decay time was calculated to prevent the fuel cladding temperature from exceeding 1100/sup 0/F. Results show that 211 hours are required following normal reactor shutdown from 55 MW reactor power before ECCS shutdown bypass actuation can be allowed if the reactor is not in cold shutdown condition. One hundred (100) seconds are required following a LOCE before ECCS shutdown bypass actuation can be allowed.

  4. Low prevalence of significant carotid artery disease in Iranian patients undergoing elective coronary artery bypass

    Karimi Fatemeh

    2007-01-01

    Full Text Available Abstract Background Coronary artery bypass grafting ranks as one of the most frequent operations worldwide. The presence of carotid artery stenosis may increase the stroke rate in the perioperative period. Routine preoperative noninvasive assessment of the carotid arteries are recommended in many institutions to reduce the stroke rate. Methods 271 consecutive patients undergoing coronary artery bypass grafting at Shaheed Madani hospital of Tabriz, Iran (age, 58.5 Y; 73.1% male underwent preoperative ultrasonography for assessment of carotid artery wall thickness. Results Plaque in right common, left common, right internal and left internal carotid arteries was detected in 4.8%, 7.4%, 43.2% and 42.1% of patients respectively. 5 patients (1.8% had significant ( Conclusion Consecutive Iranian patients undergoing elective coronary artery bypass surgery show a very low prevalence of significant carotid artery disease.

  5. Stagnant loop syndrome resulting from small-bowel irradiation injury and intestinal by-pass

    Stagnant or blind-loop syndrome includes vitamin B12 malabsorption, steatorrhea, and bacterial overgrowth of the small intestine. A case is presented to demonstrate this syndrome occurring after small-bowel irradiation injury with exaggeration postenterocolic by-pass. Alteration of normal small-bowel flora is basic to development of the stagnant-loop syndrome. Certain strains of bacteria as Bacteriodes and E. coli are capable of producing a malabsorption state. Definitive therapy for this syndrome developing after severe irradiation injury and intestinal by-pass includes antibiotics. Rapid symptomatic relief from diarrhea and improved malabsorption studies usually follow appropriate antibiotic therapy. Recolonization of the loop(s) with the offending bacterial species may produce exacerbation of symptoms. Since antibiotics are effective, recognition of this syndrome is important. Foul diarrheal stools should not be considered a necessary consequence of irradiation injury and intestinal by-pass

  6. Quasi-steady Bingham plastic analysis of an electrorheological flow mode bypass damper with piston bleed

    Lindler, Jason; Wereley, Norman M.

    2003-06-01

    We present an improved experimental validation of our nonlinear quasi-steady electrorheological (ER) and magnetorheological damper analysis, using an idealized Bingham plastic shear flow mechanism, for the flow mode of damper operation with leakage effect. To validate the model, a double-acting ER valve or bypass damper was designed and fabricated. Both the hydraulic cylinder and the bypass duct have cylindrical geometry, and damping forces are developed in the annular bypass via Poiseuille flow. The ER fluid damper contains a controlled amount of leakage around the piston head. The leakage allows ER fluid to flow from one side of the piston head to the opposite side without passing through the ER bypass. For this flow mode damper, the damping coefficient, defined as the ratio of equivalent viscous damping of the Bingham plastic material, Ceq, to the Newtonian viscous damping, C, is a function of the non-dimensional plug thickness only. The damper was tested for varying conditions of applied electric field and frequency using a mechanical damper dynamometer. In this analysis, the leakage damping coefficient with incorporated leakage effects, predict the amount of energy dissipated for a complete cycle of the piston rod. Measured force verses displacement cycles for multiple frequencies and electric fields validate the ability of the non-dimensional groups and the leakage damping coefficient to predict the damping levels for an ER bypass damper with leakage. Based on the experimental validation of the model using these data, the Bingham plastic analysis is shown to be an effective tool for the analysis-based design of double-acting ER bypass dampers.

  7. Conventional hemofiltration during cardiopulmonary bypass increases the serum lactate level in adult cardiac surgery

    Rabie Soliman

    2016-01-01

    Full Text Available Objective: To evaluate the effect of hemofiltration during cardiopulmonary bypass on lactate level in adult patients who underwent cardiac surgery. Design: An observational study. Setting: Prince Sultan cardiac center, Riyadh, Saudi Arabia. Participants: The study included 283 patients classified into two groups: Hemofiltration group (n=138, hemofiltration was done during CPB. Control group (n = 145, patients without hemofiltration. Interventions: Hemofiltration during cardiopulmonary bypass. Measurements and Main Results: Monitors included hematocrit, lactate levels, mixed venous oxygen saturation, amount of fluid removal during hemofiltration and urine output. The lactate elevated in group H than group C (P < 0.05, and the PH showed metabolic acidosis in group H (P < 0.05. The mixed venous oxygen saturation decreased in group H than group C (P < 0.05. The number of transfused packed red blood cells was lower in group H than group C (P < 0.05. The hematocrit was higher in group H than group C (P < 0.05. The urine output was lower in group H than group C (P < 0.05. Conclusions: Hemofiltration during cardiopulmonary bypass leads to hemoconcentration, elevated lactate level and increased inotropic support. There are some recommendations for hemofiltration: First; Hemofiltration should be limited for patients with impaired renal function, positive fluid balance, reduced response to diuretics or prolonged bypass time more than 2 hours. Second; Minimal amount of fluids should be administered to maintain adequate cardiac output and reduction of priming volumes is preferable to maintain controlled hemodilution. Third; it should be done before weaning of or after cardiopulmonary bypass and not during the whole time of cardiopulmonary bypass.

  8. Computational fluid dynamic analysis of core bypass flow phenomena in a prismatic VHTR

    The core bypass flow in a prismatic very high temperature reactor (VHTR) is an important design consideration and can have considerable impact on the condition of reactor core internals including fuels. The interstitial gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The occurrence of hot spots in the core and lower plenum and hot streaking in the lower plenum (regions of very hot gas flow) are affected by bypass flow. In the present study, three-dimensional computational fluid dynamic (CFD) calculations of a typical prismatic VHTR are conducted to better understand bypass flow phenomena and establish an evaluation method for the reactor core using the commercial CFD code FLUENT. Parametric calculations changing several factors in a one-twelfth sector of a fuel column are performed. The simulations show the impact of each factor on bypass flow and the resulting flow and temperature distributions in the prismatic core. Factors include inter-column gap-width, turbulence model, axial heat generation profile and geometry change from irradiation-induced shrinkage in the graphite block region. It is shown that bypass flow provides a significant cooling effect on the prismatic block and that the maximum fuel and coolant channel outlet temperatures increase with an increase in gap-width, especially when a peak radial factor is applied to the total heat generation rate. Also, the presence of bypass flow causes a large lateral temperature gradient in the block and also dramatically increases the variation in coolant channel outlet temperatures for a given block that may have repercussions on the structural integrity of the graphite, the neutronics and the potential for hot streaking and hot spots occurring in the lower plenum.

  9. Evaluation of orthotopic liver transplantation with no veno-venous bypass

    黄东胜; 郑树森; 吴健; 梁廷波; 王伟林; 沈岩; 张珉

    2002-01-01

    To assess the feasibility and outcome of orthotopic liver transplantation(OLT) with no veno-venous bypass(v-v hypass)in adult patients.Methods:Between 1999 and 2001 ,43 adult patients underwent OLT with v-v bypass,33 with no v-v bypass.The operation time,anhepatic time,amount of blood loss,amount of blood transfusion,ICU stay days of the two groups were compared.renal function and gastrointestinal function in the two groups were examined.Results:There was no significant difference in mean serum creatinine on day 3 and gas discharge time in patients with v-v bypass or not.With no v-v hypass,the average operation time was 5.7±1.3 hours,anhepatic time was 64±13 minutes,median amount of blood loss in operation was 4000±820mL,median amount of blood transfused intracperatively was 4650±910mL,median ICU stay was 5.7 days;all those were lower or shorter than those with v-v hypass.and these differences betweent the two groups had statistical significances.Conclusion:OLT with no v-v bypass is safe and can be performed in the majority of adult patients.The practice of liver transplantation with no v-v hypass is associated with shorter total operation time.shorter anhepatic time,lower blood product ussege,and shorter ICU stay compared with standard technique of OLT with routine use of v-v bypass.

  10. Mechanical rotational thrombectomy for treatment thrombolysis in acute and subacute occlusion of femoropopliteal arteries: retrospective analysis of the results from 1999 to 2005; Mechanische Rotationsthrombektomie zur Behandlung von akuten und subakuten Okklusionen der femoropoplitealen Arterien: Retrospektive Auswertung der Ergebnisse von 1999 bis 2005

    Wissgott, C.; Kamusella, P.; Richter, A.; Steinkamp, H.J. [Radiologie, DRK-Kliniken Berlin (Germany); Klein-Weigel, P. [Angiologie, DRK-Kliniken Berlin (Germany)

    2008-04-15

    Purpose: direct intra-arterial thrombolysis is the standard of care over acute surgical intervention for acute infrainguinal occlusion. However, several mechanical thrombectomy devices can be utilized as a less invasive alternative to rapid reperfusion of the acutely threatened limb. Materials end methods: retrospective analysis of 265 patients treated from 1999 to 2005, mean age 65 {+-} 8.4 (range from 47 to 75) years, with acute (85 patients, 32.1%, group 1) or subacute (180 patients, 67.9%, group 2) occlusions of the femoropopliteal artery with a rotational thromboembolectomy system (Straub Rotarex registered). The mean occlusion length was 25 (range 2 - 40) cm. Results: the technical success rate was 94.7% (251 / 265). In the additional 14 patients, no complete clot removal (n = 9) or intraluminal guidewire passage was able to be achieved (n = 5). After a mean follow-up of 12 {+-} 3 months, the restenosis rate was 49% in group 1 and 54% in group 2. The ankle-brachial index improved in group 1 from 0.32 {+-} 0.17 to 0.78 {+-} 0.24 at discharge and 0.71 {+-} 0.23 after 12 months (p {<=} 0.001) and in group 2 from preinterventional 0.47 {+-} 0.24 to 0.81 {+-} 0.19 at discharge and 0.74 {+-} 0.24 after 12 months (p {<=} 0.001). There were 16 (6%) distal embolizations and 3 (1.2%) perforations. There were no cases of amputation or death during follow-up. (orig.)

  11. Recommended number of strides for automatic assessment of gait symmetry and regularity in above-knee amputees by means of accelerometry and autocorrelation analysis

    Tura Andrea

    2012-02-01

    Full Text Available Abstract Background Symmetry and regularity of gait are essential outcomes of gait retraining programs, especially in lower-limb amputees. This study aims presenting an algorithm to automatically compute symmetry and regularity indices, and assessing the minimum number of strides for appropriate evaluation of gait symmetry and regularity through autocorrelation of acceleration signals. Methods Ten transfemoral amputees (AMP and ten control subjects (CTRL were studied. Subjects wore an accelerometer and were asked to walk for 70 m at their natural speed (twice. Reference values of step and stride regularity indices (Ad1 and Ad2 were obtained by autocorrelation analysis of the vertical and antero-posterior acceleration signals, excluding initial and final strides. The Ad1 and Ad2 coefficients were then computed at different stages by analyzing increasing portions of the signals (considering both the signals cleaned by initial and final strides, and the whole signals. At each stage, the difference between Ad1 and Ad2 values and the corresponding reference values were compared with the minimum detectable difference, MDD, of the index. If that difference was less than MDD, it was assumed that the portion of signal used in the analysis was of sufficient length to allow reliable estimation of the autocorrelation coefficient. Results All Ad1 and Ad2 indices were lower in AMP than in CTRL (P Conclusions Without the need to identify and eliminate the phases of gait initiation and termination, twenty strides can provide a reasonable amount of information to reliably estimate gait regularity in transfemoral amputees.

  12. Management of a patient with hyperkalemic periodic paralysis requiring coronary artery bypass grafts

    Sanjay Orathi Patangi

    2012-01-01

    Full Text Available Hyperkalemic periodic paralysis (HPP is an autosomal-dominant inherited muscle disease characterized by episodes of flaccid weakness and intermittent myotonia. There are no previous reports in the literature about anesthesia for cardiac surgery with cardiopulmonary bypass in this disorder. We describe perioperative anesthetic management for on-pump coronary artery bypass grafting in a 75-year-old man with a history of hyperkalemic periodic paralysis. This case report outlines our management strategy and the issues encountered during the perioperative period.

  13. Reversible hyperinsulinemic hypoglycemia after gastric bypass: a consequence of altered nutrient delivery

    McLaughlin, Tracey; Peck, Marcia; Holst, Jens; Deacon, Carolyn

    2010-01-01

    Severe hypoglycemia after Roux-en-Y gastric bypass surgery (RYGB) is an increasingly recognized condition, characterized by neuroglycopenia and inappropriately elevated insulin concentrations that occur primarily in the postprandial state. Both pathophysiology and treatment of this disorder remai...... elusive, but it has been postulated that hyperplasia and/or hypertrophy of beta-cells due to morbid obesity and/or postsurgical nesidioblastosis may contribute.......Severe hypoglycemia after Roux-en-Y gastric bypass surgery (RYGB) is an increasingly recognized condition, characterized by neuroglycopenia and inappropriately elevated insulin concentrations that occur primarily in the postprandial state. Both pathophysiology and treatment of this disorder remain...

  14. Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2016-01-01

    A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.

  15. Blood flow modeling for patient-specific bypass surgery in lower-limb arteries

    Willemet, Marie

    2012-01-01

    Every day in Belgium, at least one or two people will undergo a bypass surgery in the lower-limb arteries. This medical procedure consists of replacing an occluded section of the leg arteries with an artificial vessel, in order to allow blood to flow downwards of this blockage. Even though this intervention is very common, failure of this treatment within five years reaches up to 60%. In order to improve our understanding of the causes of bypass failure, one approach is to study the local hem...

  16. DOES TRANEXAMIC ACID REDUCE BLOOD LOSS IN OFF-PUMP CORONARY ARTERY BYPASS?

    A. Mehr-Aein; M. Sadeghi M. Madani-Civi

    2006-01-01

    Tranexamic acid is now used on a routine basis for on-pump coronary artery bypass grafting (CABG). We assessed the hemostatic effects of tranexamic acid to decrease bleeding tendency and transfusion requirements in patients undergoing off-pump coronary artery bypass surgery (OPCAB). A total of 66 patients were enrolled to elective OPCAB in a double-blind, prospective randomized study. Of these, 33 patients received tranexamic acid (15 mg/kg before the infusion of heparin and 15 mg/kg after pr...

  17. Endovascular management of an acquired aortobronchial fistula following aortic bypass for coarctation.

    O'Sullivan, Katie E

    2013-09-20

    Aortobronchial fistula (ABF) in the setting of aortic coarctation repair is very rare but uniformly fatal if untreated. Endovascular stenting of the descending aorta is now the first-choice approach for ABF presenting with haemoptysis and offers a less-invasive technique with improved outcomes, compared with open repair. We report a case of late ABF occurring following bypass for aortic coarctation. Management focused on two key manoeuvres: use of a covered endovascular stent to occlude the aortic bypass thus controlling the fistula and dilatation and stenting of native coarctation.

  18. Endovascular management of an acquired aortobronchial fistula following aortic bypass for coarctation

    O’Sullivan, Katie E.; Bolster, Ferdia; Lawler, Leo P.; Hurley, John

    2014-01-01

    Aortobronchial fistula (ABF) in the setting of aortic coarctation repair is very rare but uniformly fatal if untreated. Endovascular stenting of the descending aorta is now the first-choice approach for ABF presenting with haemoptysis and offers a less-invasive technique with improved outcomes, compared with open repair. We report a case of late ABF occurring following bypass for aortic coarctation. Management focused on two key manoeuvres: use of a covered endovascular stent to occlude the aortic bypass thus controlling the fistula and dilatation and stenting of native coarctation. PMID:24057860

  19. Longevity and admission to nursing home according to age after isolated coronary artery bypass surgery

    Thorsteinsson, Kristinn; Andreasen, Jan Jesper; Torp-Pedersen, Christian;

    2015-01-01

    O5 Longevity and admission to nursing home according to age after isolated coronary artery bypass surgery: A nationwide cohort study Kristinn Thorsteinsson, Jan Jesper Andreasen, Christian Torp Pedersen, Kirsten Fonager, Rikke Nørmark Mortensen, Kristian Kragholm, Gunnar Gislason, Lars Køber....... Aalborg, Denmark Background: Data on nursing home admission in patients >80 years of age after isolated coronary artery bypass grafting (CABG) are scarce. Aim: The purpose of this study was to evaluate longevity and subsequent admission to nursing home stratified by age in a nationwide CABG cohort...

  20. Effects Of Graphite Surface Roughness On Bypass Flow Computations For An HTGR

    Bypass flow in a prismatic high temperature gas reactor (HTGR) occurs between graphite blocks as they sit side by side in the core. Bypass flow is not intentionally designed to occur in the reactor, but is present because of tolerances in manufacture, imperfect installation and expansion and shrinkage of the blocks from heating and irradiation. It is desired to increase the knowledge of the effects of such flow, which has been estimated to be as much as 20% of the total helium coolant flow. Computational fluid dynamic (CFD) simulations can provide estimates of the scale and impacts of bypass flow. Previous CFD calculations have examined the effects of bypass gap width, level and distribution of heat generation and effects of shrinkage. The present contribution examines the effects of graphite surface roughness on the bypass flow for different relative roughness factors on three gap widths. Such calculations should be validated using specific bypass flow measurements. While such experiments are currently underway for the specific reference prismatic HTGR design for the next generation nuclear plant (NGNP) program of the U. S. Dept. of Energy, the data are not yet available. To enhance confidence in the present calculations, wall shear stress and heat transfer results for several turbulence models and their associated wall treatments are first compared for flow in a single tube that is representative of a coolant channel in the prismatic HTGR core. The results are compared to published correlations for wall shear stress and Nusselt number in turbulent pipe flow. Turbulence models that perform well are then used to make bypass flow calculations in a symmetric onetwelfth sector of a prismatic block that includes bypass flow. The comparison of shear stress and Nusselt number results with published correlations constitutes a partial validation of the CFD model. Calculations are also compared to ones made previously using a different CFD code. Results indicate that

  1. Scintigraphic assessment of focal platelet accumulations following infrainguinal bypass surgery in humans

    Nielsen, Tina G; Hesse, B; Eiberg, J; Rabøl, A; Folke, M; Schroeder, T V

    1997-01-01

    28 patients undergoing in situ vein (n = 24), composite vein-polytetrafluoroethylene (PTFE) (n = 1) or PTFE (n = 3) bypass surgery, assumed vascular injuries were recorded intraoperatively. Autologous indium-111-labelled platelets were injected into the inflow artery immediately after restoration of...... antiplatelet therapy or vein graft diameter. Only 2 of the 20 intragraft platelet depositions occurred in areas where intra-operative vascular injury was suspected. In the composite graft and the PTFE grafts, diffuse activity was observed throughout the entire bypass. In conclusion, focal activity...

  2. Adaptive mechanisms of arterial and venous coronary bypass grafts to an increase in flow demand

    Gurné, Olivier; Chenu, Patrick; Buche, Michel; Louagie, Yves; Eucher, Philippe; Marchandise, Baudouin; Rombaut, E; Blommaert, Dominique; Schroeder, Erwin

    1999-01-01

    OBJECTIVE—To compare the mechanisms by which arterial and venous grafts increase their flow during pacing induced tachycardia, early and later after coronary bypass surgery.
DESIGN—43 grafts (13 epigastric artery, 15 mammary artery, 15 saphenous vein) evaluated early (9 (3) days (mean (SD)) after bypass surgery were compared with 41 other grafts (15 epigastric, 11 mammary, 15 saphenous vein) evaluated later after surgery (mean 23 months, range 6 to 168 months) by quantitative angiography and ...

  3. Indications, algorithms, and outcomes for coronary artery bypass surgery in patients with acute coronary syndromes.

    Yerokun, Babatunde A; Williams, Judson B; Gaca, Jeffrey; Smith, Peter K; Roe, Matthew T

    2016-06-01

    For patients with a non-ST-segment elevation acute coronary syndrome (NSTE-ACS), guideline recommendations and treatment pathways focus on revascularization for definitive treatment if the patient is an appropriate candidate. Despite the widespread use of revascularization for NSTE-ACS, most patients undergo a percutaneous coronary intervention, whereas a minority of patients undergo coronary artery bypass grafting. Focusing specifically on the USA, the contemporary utilization, preoperative and perioperative considerations, and outcomes of NSTE-ACS patients undergoing coronary artery bypass grafting have not been comprehensively reviewed. PMID:26945187

  4. 75 FR 62919 - Notice of Final Federal Agency Actions on the Route 250 Bypass Interchange at McIntire Road...

    2010-10-13

    ... at McIntire Road Project in Virginia AGENCY: Federal Highway Administration (FHWA), DOT. ACTION... the Route 250 Bypass Interchange at McIntire Road project in the City of Charlottesville, Virginia... approvals for the following project in the State of Virginia: Route 250 Bypass Interchange at McIntire...

  5. Cutting Balloon-Assisted Angioplasty of an Anastomotic Carotid-Brachial Bypass Graft Stenosis: A Case Report

    Neointimal hyperplasia leads to anastomotic stenosis in bypass grafts. These stenoses are often resistant to conventional balloon dilatation. We present a case of a carotid-brachial bypass graft stenosis, which was treated by a 5-mm cutting balloon angioplasty with a good angiographic and clinical result

  6. Experimental and Numerical Evaluation of the By-Pass Flow in a Catalytic Plate Reactor for Hydrogen Production

    Sigurdsson, Haftor Örn; Kær, Søren Knudsen

    2011-01-01

    Numerical and experimental study is performed to evaluate the reactant by-pass flow in a catalytic plate reactor with a coated wire mesh catalyst for steam reforming of methane for hydrogen generation. By-pass of unconverted methane is evaluated under different wire mesh catalyst width to reactor...

  7. A case-controlled evaluation of the Medtronic Resting Heart System compared with conventional cardiopulmonary bypass in patients undergoing isolated coronary artery bypass surgery†

    Nozohoor, Shahab; Johnsson, Per; Scicluna, Sara; Wallentin, Per; Andell, Elisabeth; Nilsson, Johan

    2012-01-01

    The Medtronic Resting Heart System (RHS) is a heparin-coated, closed perfusion circuit. Clinical results indicate less haemodilution and reduced complement activation, when compared with a traditional circuit leading to fewer postoperative blood transfusions. We evaluated the potential clinical benefits, including reduced transfusion requirements, when using the RHS compared with conventional cardiopulmonary bypass (cCPB). The study group (n = 330) consisted of patients undergoing isolated co...

  8. The bypass solution as a capacity enhancing measure in connecting biogas plants to the grid; Die Bypass-Loesung als kapazitaetserhoehende Massnahme beim Netzanschluss von Biogasanlagen

    Grassmann, Nils [PwC Legal AG, Frankfurt am Main (Germany). Bereich Energierecht in der Region Sued; Reinhardt, Anja [PwC Legal AG, Muenchen (Germany)

    2012-07-01

    In spite of repeated amendments to the laws governing the connection of biogas plants to the grid there still remain unresolved disputes in practice. A significant issue in this regard concerns what is referred to as the bypass solution, where a connection to the general supply grid of the receiving grid operator is created and at the same time technical equipment is installed which provides a connection to an upstream grid to which biogas can be backfed in times of low grid load. The Upper Regional Court of Duesseldorf classifies constellations of this kind as a combined grid connection to two different grids. It argues that since the legislature has provided no regulations on this constellation there can be no legitimate right to obtaining a connection of this configuration. However, this line of argumentation does not appear compelling. The meaning and purpose of Articles 31 ff. of the Gas Network Access Ordinance and the wording of the relevant norms both speak in favour of considering bypass solutions as capacity-enhancing measures. The receiving (downstream) grid operator would then be obliged, under the general requirements, to create a grid connection and to draw the bypass solution into consideration as a special means of backfeeding. This would provide legal certainty for all involved and allow technically meaningful solutions to be implemented.

  9. [Evaluation of the addition of counterpulsation to the partial left ventricular-femoral bypass for limitation of evolving myocardial infarction].

    Yamaguchi, A; Ide, H; Ino, T; Adachi, H; Mizuhara, A; Kawahito, K; Murata, S

    1994-08-01

    The effect of adding counterpulsation to a partial left ventricular bypass was evaluated in a canine model of acute myocardial ischemia by using a myocardial staining method. To establish a left ventricular bypass, a catheter consisting of bypass tube (90 cm in length and 15 Fr in inner diameter) and an accompanying intraaortic balloon as a single apparatus (Integrated Cardioassist Catheter; ICAC) was introduced into the left ventricle via the abdominal aorta. The left ventricular bypass was adjusted to 1 L/min. with or without counterpulsation with the aid of a centrifugal pump and IABP console. The use of the ICAC that provided pulsatile left ventricular bypass tended to raise the mean aortic pressure and cardiac output. Reduction of the tension time index was noted with the use of the ICAC in contrast to the control. And increment of the DPTI/TTI ratio was observed with the use of the ICAC in contrast to the control and partial left ventricular bypass alone. While the percentages of the region at risk were similar [17.3 +/- 9.5% (control), vs. 16.4 +/- 3.4% (partial left ventricular bypass alone) vs. 16.9 +/- 5.2% (ICAC)], the percentages of infarct sizes were reduced due to the use of counterpulsation. [61.9 +/- 12.2% (control), vs. 57.5 +/- 3.9% (partial left ventricular bypass alone) vs. 16.8 +/- 6.0% (ICAC)]. These results revealed that the addition of counterpulsation alleviates afterload reduction to the partial left ventricular bypass and was more beneficial to the reduction of the infarct size than partial left ventricular bypass alone. PMID:7963829

  10. 4D flow MRI assessment of extracranial-intracranial bypass: qualitative and quantitative evaluation of the hemodynamics

    Sekine, Tetsuro [University Hospital Zurich/University of Zurich, Department of Medical Radiology, Division of Nuclear Medicine, Zurich (Switzerland); Nippon Medical School, Department of Radiology, Tokyo (Japan); Takagi, Ryo; Amano, Yasuo; Orita, Erika; Matsumura, Yoshio; Kumita, Shin-ichiro [Nippon Medical School, Department of Radiology, Tokyo (Japan); Murai, Yasuo [Nippon Medical School, Department of Neurological Surgery, Tokyo (Japan)

    2016-03-15

    Our aim was to assess the feasibility of using time-resolved 3D phase-contrast (4D flow) MRI to characterize extracranial-intracranial (EC-IC) bypass. We enrolled 32 patients who underwent EC-IC bypass (15 men, 17 women; mean age 66.4 years). In all, 16 underwent radial artery graft (RAG) bypass and 16 underwent superficial temporal artery (STA) bypass. 4D flow MRI, time-of-flight (TOF) magnetic resonance angiography (MRA), and computed tomography angiography (CTA) were performed. Bypass patency, flow direction, and blood flow volume (BFV) of each artery were determined by 4D flow MRI. Arterial diameters were measured by TOF-MRA and CTA. We compared RAG and STA bypasses by evaluating the flow direction and BFV of each artery. We evaluated the correlation between arterial diameters (measured by CTA or MRA) and the BFV and the detectability of flow direction (measured by 4D flow MRI) of each artery. 4D flow MRI confirmed the patency of each bypass artery. Flow direction of the M1 segment of the middle cerebral artery and BFV in the bypass artery differed between RAG and STA groups (p < 0.01). BFV in the bypass slightly correlated with the diameters on CTA (p < 0.05, R{sup 2} = 0.287). Of the 29 arteries in the circle of Willis, nine were not depicted on 4D flow MRI. Cutoff values for arterial diameters on CTA and TOF-MRA for detecting the artery on 4D flow MRI were 2.4 and 1.8 mm, respectively. 4D flow MRI provided unique information for characterizing EC-IC bypasses, although this detectability is limited when addressing small arteries with slow flow. (orig.)

  11. Adherence to treatment after coronary bypass surgery: Psychological aspects

    Maria V. Iakovleva

    2016-01-01

    Full Text Available Poor adherence to treatment is a problem of great importance and striking magnitude. Its consequences are increased health care costs and poor health outcomes. It defined the objective of this research, which is the study of psychological characteristics of patients with different degrees of adherence to rehabilitation treatment after coronary bypass surgery. Ninety male and female patients with CHD, aged 46---71, were examined. The study was carried out using the questionnaire of ways of coping and the technique for diagnosing the types of attitude toward the disease, and the study of medical history. The analysis of the types of attitude toward the disease revealed that adherent patients show higher values on the harmonious type; patients with poor adherence show higher values on the apathetic, as well as the melancholic type of attitude toward illness. This study shows that wide range of psychological characteristics is significant for the definition of adherence to treatment. It is essential to consider the patient’s personality and his characteristics, such as attitude toward the disease, because they influence the adherence and, therefore, the effectiveness of therapy in the postoperative period. La escasa adherencia a la terapia es un problema de gran importancia ampliamente extendido. Sus consecuencias son el aumento de costes del tratamiento y su baja eficacia. El objetivo de la investigación fue el estudio de las características psicológicas de pacientes con diferentes grados de adherencia al tratamiento de rehabilitación después de la cirugía de derivación coronaria. Se recogieron datos clínicos de 90 pacientes de ambos sexos con cardiopatía coronaria, sometidos a cirugía de derivación coronaria, con edades comprendidas entre 46-71 a˜nos. Los cuestionarios administrados fueron el cuestionario de estilos de afrontamiento y la técnica de diagnóstico de tipos de actitud hacia la enfermedad. Además se realizó un estudio

  12. A Case of Nonalcoholic Steatohepatitis and Small Intestinal Bacterial Overgrowth with Peripheral Edema Caused by Intestinal Bypass Surgery and Relieved by Repair

    Sung, Young Kyung; Gwak, Geum Youn; Choi, Moon Seok; Koh, Kwang Chul; Paik, Seung Woon; Yoo, Byung Chul; Lee, Joon Hyeok

    2012-01-01

    Intestinal bypass surgery, particularly jejuno-ileal bypass surgery, performed for the purpose of weight reduction may cause an unexpected exacerbation of nonalcoholic steatohepatitis (NASH). Here, we report a case of NASH caused by small intestinal bacterial overgrowth, which developed after jejuno-colic bypass surgery and resolved dramatically after surgical correction.

  13. Analysis of circulatory mitochondrial DNA level after cardiac surgery with cardiopulmonary bypass and potential prognostic implications.

    Qin, Chaoyi; Gu, Jun; Qian, Hong; Meng, Wei

    2016-01-01

    Our research letter found that circulatory mtDNA level increased after the end of CPB and positive correlations between mtDNA and peak CRP level, peak BNP level, and peak PCT level, which revealed the prognostic role of perioperative circulatory mtDNA level in patients who underwent cardiopulmonary bypass. PMID:27316503

  14. Bariatric Bypass Surgery to Resolve Complicated Childhood Morbid Obesity: Case Report Study: Erratum.

    2016-05-01

    In the article ''Bariatric Bypass Surgery to Resolve Complicated Childhood Morbid Obesity: Case Report Study'', which appeared in Volume 94, Issue 49 of Medicine, Dr. Elrazek's name was incorrectly presented as Abd Elrazek M. Ali Hussein when it should have read Abd Elrazek Abd Elrazek. The article has since been corrected online. PMID:27231816

  15. Pancreaticoduodenectomy in Patients with a History of Roux-en Y Gastric Bypass Surgery

    Jeffrey M Hardacre

    2009-03-01

    Full Text Available Context Roux-en Y gastric bypass surgery is the most common operation for treatment of morbid obesity. The approach to pancreaticoduodenal resection in patients with a history of Roux-en Y gastric bypass is not well described. Case reports Pancreaticoduodenal resection was performed in two patients with distal bile duct strictures, with a past history of Roux-en Y gastric bypass. In both cases the remnant stomach, distal bile duct, duodenum and pancreas were excised. The biliopancreatic limb was divided close to the ligament of Treitz and brought up into the supracolic compartment in a retromesenteric manner and pancreatic and biliary anastomoses performed. The previous enteroenterostomy and gastrojejunal anastomoses were left intact. Both patients had an uncompleted post-operative recovery. The mean operating time was 6.5 hours and mean estimated blood loss was 525 mL. They were discharged home by days 6 and 7 post-operatively. Conclusions Pancreaticoduodenal resection can be successfully performed following Roux-en Y gastric bypass with en-bloc excision of the remnant stomach, with the pancreas and bile duct anastomosed to the divided biliopancreatic limb.

  16. Removal of thrombus from aortocoronary bypass grafts and coronary arteries using the 6Fr hydrolyser

    vanOmmen, VG; vandenBos, AA; Pieper, M; denHeyer, P; Thomas, MR; Ozbeck, S; Bar, FW; Wellens, HJJ

    1997-01-01

    This study evaluates the feasibility and safety of a 6Fr hydrodynamic thrombectomy catheter, the Hydrolyser, in native coronary arteries and aortocoronory bypass grafts. With use of a conventional contrast injector, saline solution is injected into the narrow lumen of the catheter which makes a 180

  17. Microbubbles detection during cardiopulmonary bypass with transoesophageal echocardiography: a case report

    Zanatta, Paolo; Bosco, Enrico; Salandin, Valeria; Salvador, Loris; Valfrè, Carlo; Sorbara, Carlo

    2008-01-01

    Introduction Microembolic signals are usually detected with transcranial doppler during cardiac surgery. This report focuses on suggesting the transesophageal echocardiography as a different diagnostic approach to detect microemboli during cardiopulmonary bypass. Case presentation A 58 year old male patient, caucasian race, was operated on video assisted minimally invasive mitral valve repair using right minithoracotomy approach. His past medical history included an uncontrolled hypertension,...

  18. Leptomeningeal contrast enhancement in moyamoya: its potential role in postoperative assessment of circulation through the bypass

    Leptomeningeal contrast enhancement (LMCE) is one of the MRI features of moyamoya. Its clinical significance, however, is not elucidated. Our purpose was to characterise LMCE on MRI and to evaluate its role in the assessment of circulation through a surgically established bypass in moyamoya. We studied 16 patients with idiopathic moyamoya (seven males, nine females, includingt four children, aged 7 to 54 years, mean 24 years) who underwent T1-weighted MRI before and after intravenous contrast medium. The presence of LMCE, its intensity and anatomical distribution, catheter angiographic findings, and relation of LMCE to the bypass surgery were assessed. More LMCE was seen in the cerebrum in most patients with moyamoya than in normal controls. LMCE in the brain stem and cerebellum was minimal, similar to that seen in the controls. LMCE was less prominent following surgery than before operation or in patients who did not undergo surgery. In three patients examined both before and after operation LMCE became less prominent following bypass surgery. As LMCE becomes less prominent after ''effective'' bypass surgery, this may be used for evaluation of effectiveness of surgery in moyamoya. (orig.)

  19. Leptomeningeal contrast enhancement in moyamoya: its potential role in postoperative assessment of circulation through the bypass

    Komiyama, M.; Nakajima, H.; Nishikawa, M.; Yasui, T. [Dept. of Neurosurgery, Osaka City General Hospital (Japan); Kitano, S.; Sakamoto, H. [Dept. of Paediatric Neurosurgery, Osaka City General Hospital (Japan)

    2001-01-01

    Leptomeningeal contrast enhancement (LMCE) is one of the MRI features of moyamoya. Its clinical significance, however, is not elucidated. Our purpose was to characterise LMCE on MRI and to evaluate its role in the assessment of circulation through a surgically established bypass in moyamoya. We studied 16 patients with idiopathic moyamoya (seven males, nine females, includingt four children, aged 7 to 54 years, mean 24 years) who underwent T1-weighted MRI before and after intravenous contrast medium. The presence of LMCE, its intensity and anatomical distribution, catheter angiographic findings, and relation of LMCE to the bypass surgery were assessed. More LMCE was seen in the cerebrum in most patients with moyamoya than in normal controls. LMCE in the brain stem and cerebellum was minimal, similar to that seen in the controls. LMCE was less prominent following surgery than before operation or in patients who did not undergo surgery. In three patients examined both before and after operation LMCE became less prominent following bypass surgery. As LMCE becomes less prominent after ''effective'' bypass surgery, this may be used for evaluation of effectiveness of surgery in moyamoya. (orig.)

  20. Prediction of bypass flows in HTR-PM by the flow network method

    The high temperature gas-cooled reactor is moderated by many graphite bricks. Gaps between graphite reflectors are possible flow paths that some fraction of cold helium may directly enter the hot plenum without being heated, which is a kind of bypass flow. The ratio of the bypass flows to the total flow is a key factor related to the peak fuel temperature in the normal operation of the reactor. Gaps are widely distributed in three dimensional structures, thus building proper flow network is the practical means to describe all the main flow and bypass flow paths by assigning proper nodes and links of the flow network. Graphically illustrated in the V power simulator platform, a preliminary flow network was built for the main flow and bypass flow paths. As the resistance performances of all flow paths determined by empirical formulas or CFD tools, the flow network was solved to show the effects of total mass flow rate, outlet pressure as well as the gap size on the mass flow distributions. (author)

  1. Oral bioavailability of moxifloxacin after Roux-en-Y gastric bypass surgery

    De Smet, Julie; Colin, Pieter; De Paepe, Peter; Ruige, Johannes; Batens, Helene; Van Nieuwenhove, Yves; Vogelaers, Dirk; Blot, Stijn; Van Bocxlaer, Jan; Van Bortel, Luc M.; Boussery, Koen

    2012-01-01

    Objectives: Roux-en-Y gastric bypass surgery is the most commonly performed procedure for the treatment of morbid obesity. This anatomical alteration may affect the absorption and consequently the bioavailability of oral drugs. This study aims to investigate the oral bioavailability of moxifloxacin

  2. Numerical Simulation of Coronary Artery Bypass Graft with an Assistant Graft

    WANG Wei; WANG Feng

    2014-01-01

    The conventional bypass design is to implant a graft on the stenosed host artery allowing blood to flow bypass the stenotic artery. However, restenosis is a challenging problem which finally results in reoperation. The purpose of this paper is to propose a new bypass graft design of coronary artery with an assistant graft for the treatment of coronary artery stenosis. An additional assistant graft was employed in the new design compared with the conventional ETS anastomosis. Numerical simulations were performed by means of finite volume method using computational fluid dynamics (CFD) solver. Results demonstrated that the new anastomoses model provided a more smooth flow at the distal ETS anastomosis without any stagnation point on anastomotic bed and vortex formation in the heel region. Oscillatory shear index (OSI) and time-averaged wall shear stress gradient (TAWSSG) at the artery bed of the distal ETS anastomosis were reduced. The coronary artery bypass graft with an assistant graft is feasible to improve the local hemodynamics and diminish the probability of restenosis in the treatment of coronary artery stenosis.

  3. Is the use of albumin in colloid prime solution of cardiopulmonary bypass circuit justified?

    Boks, RH; van Herwerden, LA; Takkenberg, JJM; van Oeveren, W; Gu, YJ; Wijers, MJ; Bogers, AJJC

    2001-01-01

    Background. Albumin in the priming solution precoats the surface of the cardiopulmonary bypass circuit, supposedly causing delayed adsorption of fibrinogen and reduced activation and adhesion of platelets. This action may result in lower transoxygenator resistance. Because our institution uses a col

  4. The roles of aldehyde dehydrogenases (ALDHs in the PDH bypass of Arabidopsis

    Lin Ming

    2009-03-01

    Full Text Available Abstract Background Eukaryotic aldehyde dehydrogenases (ALDHs, EC 1.2.1, which oxidize aldehydes into carboxylic acids, have been classified into more than 20 families. In mammals, Family 2 ALDHs detoxify acetaldehyde. It has been hypothesized that plant Family 2 ALDHs oxidize acetaldehyde generated via ethanolic fermentation, producing acetate for acetyl-CoA biosynthesis via acetyl-CoA synthetase (ACS, similar to the yeast pathway termed the "pyruvate dehydrogenase (PDH bypass". Evidence for this pathway in plants has been obtained from pollen. Results To test for the presence of the PDH bypass in the sporophytic tissue of plants, Arabidopsis plants homozygous for mutant alleles of all three Family 2 ALDH genes were fed with 14C-ethanol along with wild type controls. Comparisons of the incorporation rates of 14C-ethanol into fatty acids in mutants and wild type controls provided direct evidence for the presence of the PDH bypass in sporophytic tissue. Among the three Family 2 ALDHs, one of the two mitochondrial ALDHs (ALDH2B4 appears to be the primary contributor to this pathway. Surprisingly, single, double and triple ALDH mutants of Arabidopsis did not exhibit detectable phenotypes, even though a Family 2 ALDH gene is required for normal anther development in maize. Conclusion The PDH bypass is active in sporophytic tissue of plants. Blocking this pathway via triple ALDH mutants does not uncover obvious visible phenotypes.

  5. Drug disposition and modelling before and after gastric bypass: immediate and controlled-release metoprolol formulations

    Gesquiere, Ina; Darwich, Adam S; Van der Schueren, Bart; de Hoon, Jan; Lannoo, Matthias; Matthys, Christophe; Rostami, Amin; Foulon, Veerle; Augustijns, Patrick

    2015-01-01

    The aim of the present study was to evaluate the disposition of metoprolol after oral administration of an immediate and controlled-release formulation before and after Roux-en-Y gastric bypass (RYGB) surgery in the same individuals and to validate a physiologically based pharmacokinetic (PBPK) model for predicting oral bioavailability following RYGB.

  6. Iron Deficiency After Roux-en-Y Gastric Bypass: Insufficient Iron Absorption from Oral Iron Supplements

    Gesquiere, Ina; Lannoo, Matthias; Augustijns, Patrick; Matthys, Christophe; Van der Schueren, Bart; Foulon, Veerle

    2014-01-01

    Roux-en-Y gastric bypass (RYGB) may reduce the absorption of iron, but the extent to which this absorption is impeded is largely unknown. First, we determined the prevalence of iron deficiency following RYGB and explored the risk factors for its development. Second, we examined to what extent oral iron supplements are absorbed after RYGB.

  7. Pregnant woman with fatal complication after laparoscopic Roux-en-Y gastric bypass

    Renault, Kristina; Gyrtrup, Hans Jørgen; Damgaard, Karen;

    2012-01-01

    In Europe, an increasing number of women have bariatric surgery; therefore, obstetricians are likely to encounter these patients. We report a 22-year-old woman, who had previously undergone uncomplicated laparoscopic Roux-en-Y gastric bypass. She was admitted with severe abdominal pain at 35 week...... surgeons experienced in bariatric surgery, as well as radiologists with specific knowledge of relevant imaging procedures....

  8. Multiple Rad5 activities mediate sister chromatid recombination to bypass DNA damage at stalled replication forks.

    Minca, Eugen C; Kowalski, David

    2010-06-11

    DNA damage that blocks replication is bypassed in order to complete chromosome duplication and preserve cell viability and genome stability. Rad5, a PCNA polyubiquitin ligase and DNA-dependent ATPase in yeast, is orthologous to putative tumor suppressors and controls error-free damage bypass by an unknown mechanism. To identify the mechanism in vivo, we investigated the roles of Rad5 and analyzed the DNA structures that form during damage bypass at site-specific stalled forks present at replication origins. Rad5 mediated the formation of recombination-dependent, X-shaped DNA structures containing Holliday junctions between sister chromatids. Mutants lacking these damage-induced chromatid junctions were defective in resolving stalled forks, restarting replication, and completing chromosome duplication. Rad5 polyubiquitin ligase and ATPase domains both contributed to replication fork recombination. Our results indicate that multiple activities of Rad5 function coordinately with homologous recombination factors to enable replication template switch events that join sister chromatids at stalled forks and bypass DNA damage. PMID:20541998

  9. Effect of acetylcysteine on adaptation of intestinal smooth muscle after small bowel bypass

    The authors have postulated that the adaptive changes in function and structure of bypassed segments of small bowel are due in part to the change in intestinal contents following operation. The purpose of these experiments was to determine if a mucolytic agent could alter the adaptation. Rats were anesthetized and a 70% jejunoileal bypass was performed. The bypassed segments then were perfused with either saline or acetylcysteine for 3-12 days. Then, either intestinal transit was determined using Cr-51, or segments were taken for morphometric analysis. Transit, as assessed by the geometric center, was increased 32% by acetylcysteine treatment. Treatment also caused a decrease in hypertrophy of the muscularis. Muscle wet weight, muscle cross-sectional area, and muscle layer thickness all were significantly less in those animals infused with acetyl-cysteine. No decreases in hypertrophy were seen in the in-continuity segments. These data indicate that alterations in intestinal content can affect the course of adaptation of intestinal muscle in response to small bowel bypass

  10. In situ cephalic vein bypasses from axillary to the brachial artery after catheterization injuries.

    Hudorovic, Narcis; Lovricevic, Ivo; Ahel, Zaky

    2010-07-01

    The need to bypass to the brachial artery is rare. Over a five-year period, 16 patients had suffered iatrogenic post-catheterization injuries of the upper extremity. We have performed 16 bypasses, in 16 patients, mean age was 65 years (range 47-75), to the brachial artery originating from an artery proximal to the shoulder joint. In all cases, the axillary artery was the donor artery. All bypasses were created by using the cephalic vein with the in situ technique and distal anastomoses were made to a distance-free section of brachial artery. No operative mortality, neurological complications or major upper-extremity amputation was associated with the procedure. Life-long-conduit analysis showed 75% patency in the five-year period. After iatrogenic post-catheterization trauma of arterial system of upper extremity, bypasses from axillary to brachial artery with the cephalic vein with the in situ technique is a safe operation with satisfactory long-term patency. PMID:20395248

  11. The Effect of Low Tidal Volume Ventilation during Cardiopulmonary Bypass on Postoperative Pulmonary Function

    Gholamreza Safarpour

    2010-08-01

    Full Text Available Background: Postoperative pulmonary dysfunction is one of the most frequent complications after cardiac surgery and it is believed to result from the use of cardiopulmonary bypass (CPB. In this study, we investigated the effect of low tidal volume ventilation during CPB on postoperative gas exchange and lung mechanics.Methods: This prospective randomized study included 100 patients undergoing elective coronary artery bypass grafting. In 50 patients, low tidal volume ventilation [tidal volume (TV = 3 ml/kg, respiratory rate (RR = 12/min, fraction of inspiratory oxygen (FIO2= 1.0, positive end expiratory pressure (PEEP = 5 cmH2O] was applied during CPB (group I; and in the other 50 patients (group II, the lungs were open to the atmosphere without ventilation. Measurements were taken preoperatively,after CPB, and before discharge.Results: Post-bypass PaO2 (just after CPB 85 versus75 was higher significantly in group I (P value < 0.05. Decrease in postoperative forced expiratory volume in 1 second (25% versus 30% and forced vital capacity (32% versus 35% was less significant in group I. Also, time to extubation (5 hrs versus 5.5 hrs was shorter in group I.Conclusion: Continued low tidal volume ventilation during CPB improved post-bypass oxygenation and lung mechanics.

  12. Judicial bypass of parental consent for abortion: characteristics of pregnant minor "Jane Doe's".

    Friedman, Susan Hatters; Hendrix, Todd; Haberman, Jessica; Jain, Abhishek

    2015-06-01

    Pregnant minors can obtain an abortion without parental consent through a judicial bypass procedure in 38 states. To grant such a petition in Ohio, the Court must determine that the young woman is either "sufficiently mature and well enough informed to intelligently decide whether to have an abortion," or that notification of her parents is "not in her best interest," usually due to abuse. For the sake of anonymity in these emotionally and politically charged cases, the evaluee is referred to as "Jane Doe." This project sought to describe characteristics of teenagers seeking judicial bypass for abortion, which have not been well described in the scientific literature. Data were collected from Jane Doe evaluations completed at a metropolitan juvenile court psychiatric clinic, over 3 years. The mean age of the evaluees (N = 55) was 16.4 years. The vast majority (95%) were granted a judicial bypass. They usually had long-term boyfriends of comparable age. They had often told trusted adults about their pregnancy, though not their parents, due to concerns of violence or being excluded from the family. This study presents the first comprehensive description of characteristics of minors seeking judicial bypasses for abortion. Psychiatrists may apply general principles of informed consent in such evaluations, including ascertaining whether the decision is being made voluntarily, knowingly, and with sufficient decision-making capacity. PMID:26034870

  13. Safety experience with the duodenal-jejunal bypass liner: an endoscopic treatment for diabetes and obesity

    Betzel, B; Koehestanie, P.; Aarts, E.O.; Dogan, K.; Homan, J.; Janssen, I.M.C.; Wahab, P.J.; Groenen, M.J.; Berends, F.J.

    2015-01-01

    BACKGROUND: The duodenal-jejunal bypass liner (DJBL) is a new, device-based endoscopic treatment for type 2 diabetes mellitus (T2DM) and obesity. OBJECTIVE: To report serious safety events of subjects treated with the DJBL while offering a simple guideline to mitigate risk. DESIGN: Single-center obs

  14. Overexpression of isocitrate lyase-glyoxylate bypass influence on metabolism in Aspergillus niger

    Meijer, Susan Lisette; Otero, José Manuel; Olivares Hernandez, Roberto;

    2009-01-01

    In order to improve the production of succinate and malate by the filamentous fungus Aspergillus niger the activity of the glyoxylate bypass pathway was increased by over-expression of the isocitrate lyase (icl) gene. The hypothesis was that when isocitrate lyase was up-regulated the flux towards...

  15. Arterial pressure during cardiopulmonary bypass is not associated with acute kidney injury

    Kandler, K; Jensen, M E; Nilsson, J C;

    2015-01-01

    BACKGROUND: Acute kidney injury (AKI) after cardiac surgery is common and is associated with increased mortality. We wanted to investigate if the arterial pressure or the use of norepinephrine during cardiopulmonary bypass were associated with AKI. METHODS: A retrospective analysis of patients who...

  16. DIET MICRONUTRIENT ADEQUACY OF WOMEN AFTER 1 YEAR OF GASTRIC BYPASS

    LEIRO, Larissa Silveira; Melendez-ARAÚJO, Mariana Silva

    2014-01-01

    Background The more effective treatment for severe obesity is bariatric surgery. Gastric bypass is a surgical technique used worldwide; however, as well as other techniques; it has postoperative risks, including nutrient deficiency. Aim To determine the amounts of dietary iron, calcium, vitamin D and vitamin B12 ingested by patients of a public hospital one year after gastric bypass, and compare with the recommendations of the Recommended Dietary Allowances. Methods This was a transverse descriptive study and the sample consisted of 36 women, with at least one year of gastric bypass. Data collected included sociodemographic, anthropometric and diet variables. Dietetic information was collected through a validated food frequency questionnaire. Ingestion of iron, calcium, vitamin D and vitamina B12 was evaluated in comparison with the Recommended Dietary Allowances, as well as correlation of micronutrient ingestion with time of surgery. Results There was inadequate consumption of iron, calcium and vitamin D. The vitamin B12 intake was considered adequate. There was statistically significant positive correlation between the time of surgery and the ingestion of iron, vitamin B12 and vitamin D. Conclusion The intake of iron, calcium and vitamin D of women one year after gastric bypass was inadequate, emphasizing the importance of multiprofessional monitoring postoperatively to prevent nutrient deficiencies. PMID:25409960

  17. Duodenal-jejunal bypass sleeve - a potential alternative to bariatric surgery?

    Rohde, Ulrich; Gylvin, Silas; Vilmann, Peter;

    2014-01-01

    Overweight and obesity are risk factors for several co-morbidities reducing life expectancy. Conservative treatment of obesity is generally ineffective in the long-term. Bariatric surgery has proven effective, but is associated with potential complications. Duodenal-jejunal bypass sleeve is a novel...

  18. Modelling of the bypass-transition in the linear turbine blade cascade

    Straka, P.; Příhoda, Jaromír

    Vienna: Vienna University of Technology, 2012, s. 1-15. ISBN 978-3-9502481-9-7. [ECCOMAS 2012 /6./. Vienna (AT), 10.09.2012-14.09.2012] R&D Projects: GA ČR(CZ) GAP101/10/1329 Institutional support: RVO:61388998 Keywords : computational fluid dynamics * bypass-transition * turbomachinery Subject RIV: BK - Fluid Dynamics

  19. Lymphaticovenous Bypass Decreases Pathologic Skin Changes in Upper Extremity Breast Cancer-Related Lymphedema

    Torrisi, Jeremy S.; Joseph, Walter J.; Ghanta, Swapna; Cuzzone, Daniel A.; Albano, Nicholas J.; Savetsky, Ira L.; Gardenier, Jason C.; Skoracki, Roman; Chang, David; Mehrara, Babak J.

    2015-01-01

    Introduction: Recent advances in microsurgery such as lymphaticovenous bypass (LVB) have been shown to decrease limb volumes and improve subjective symptoms in patients with lymphedema. However, to date, it remains unknown if these procedures can reverse the pathological tissue changes associated with lymphedema. Therefore, the purpose of this study was to analyze skin tissue changes in patients before and after LVB.

  20. Effect of cardiopulmonary bypass on leukocyte activation : changes in membrane-bound elastase on neutrophils

    Tang, M; Gu, YJ; Wang, WJ; Xu, YP; Chen, CZ

    2004-01-01

    Background: Neutrophil elastase is known to be released from the activated leukocytes as a result of cardiopulmonary bypass (CPB). However, its biological effect on organ injury is questionable because it is quickly bound by natural proteinase inhibitors (PIs). Recently, membrane-bound elastase ( MB

  1. Hematological Disorders following Gastric Bypass Surgery: Emerging Concepts of the Interplay between Nutritional Deficiency and Inflammation

    Mingyi Chen

    2013-01-01

    Full Text Available Obesity and the associated metabolic syndrome are among the most common and detrimental metabolic diseases of the modern era, affecting over 50% of the adult population in the United States. Surgeries designed to promote weight loss, known as bariatric surgery, typically involve a gastric bypass procedure and have shown high success rates for treating morbid obesity. However, following gastric bypass surgery, many patients develop chronic anemia, most commonly due to iron deficiency. Deficiencies of vitamins B1, B12, folate, A, K, D, and E and copper have also been reported after surgery. Copper deficiency can cause hematological abnormalities with or without neurological complications. Despite oral supplementation and normal serum concentrations of iron, copper, folate, and vitamin B12, some patients present with persistent anemia after surgery. The evaluation of hematologic disorders after gastric bypass surgery must take into account issues unique to the postsurgery setting that influence the development of anemia and other cytopenias. In this paper, the clinical characteristics and differential diagnosis of the hematological disorders associated with gastric bypass surgery are reviewed, and the underlying molecular mechanisms are discussed.

  2. Endotoxin release in cardiac surgery with cardiopulmonary bypass : pathophysiology and possible therapeutic strategies. An update

    Kats, Suzanne; Schonberger, Jacques P. A. M.; Brands, Ruud; Seinen, Willem; van Oeveren, Wim

    2011-01-01

    Cardiac surgery with cardiopulmonary bypass provokes a systemic inflammatory response syndrome caused by the surgical trauma itself, blood contact with the non-physiological surfaces of the extracorporeal circuit, endotoxemia, and ischemia. The role of endotoxin in the inflammatory response syndrome

  3. California's Yolo Bypass: Evidence that flood control can be compatible with fisheries, wetlands, wildlife, and agriculture

    Sommer, T.; Harrell, B.; Nobriga, M.; Brown, R.; Moyle, P.B.; Kimmerer, W.; Schemel, Laurence E.

    2001-01-01

    Unlike conventional flood control systems that frequently isolate rivers from ecologically-essential floodplain habitat, California's Yolo Bypass has been engineered to allow Sacramento Valley floodwaters to inundate a broad floodplain. From a flood control standpoint, the 24,000 ha leveed floodplain has been exceptionally successful based on its ability to convey up to 80% of the flow of the Sacramento River basin during high water events. Agricultural lands and seasonal and permanent wetlands within the bypass provide key habitat for waterfowl migrating through the Pacific Flyway. Our field studies demonstrate that the bypass seasonally supports 42 fish species, 15 of which are native. The floodplain appears to be particularly valuable spawning and rearing habitat for the splittail (Pogonichthys macrolepidotus), a federally-listed cyprinid, and for young chinook salmon (Oncorhynchus tshawytscha), which use the Yolo Bypass as a nursery area. The system may also be an important source to the downstream food web of the San Francisco Estuary as a result of enhanced production of phytoplankton and detrital material. These results suggest that alternative flood control systems can be designed without eliminating floodplain function and processes, key goals of the 1996 Draft AFS Floodplain Management Position Statement.

  4. APROTININ PRESERVES HEMOSTASIS IN ASPIRIN-TREATED PATIENTS UNDERGOING CARDIOPULMONARY BYPASS

    TABUCHI, N; HUET, RCG; STURK, A; EIJSMAN, L; WILDEVUUR, CRH

    1994-01-01

    Various clinical trials have shown that hemostasis is improved by the administration of aprotinin during cardiopulmonary bypass. However, this effect has not been proved for those patients treated preoperatively with aspirin. Therefore, a double-blind, placebo-controlled study was conducted to test

  5. [Stented dilated or varicose veins as arterial bypass transplants: experimental and initial clinical results].

    Moritz, A; Magometschnigg, H; Staudacher, M; Ptakovsky, H; Raderer, F; Ullrich, R; Grabenwöger, F; Wolner, E

    1991-01-01

    Dilated and varicose veins are usually not used as arterial bypass-grafts despite they are lined with functional endothelium. External support by a constrictive mesh tube could conform these veins into evenly calibrated bypass-grafts. Ovine jugular veins could be constricted from 15 to 6 mm diameter without forming folds on the inner flow surface. 6 months after implantation of 5 cm long jugular vein segments into the carotid arteries of 7 sheep the inner diameter was 19.5 +/- 3.3 mm for native veins (n = 4) and 7.6 +/- 0.8 mm for constricted veins (n = 10). Intimal hyperplasia was reduced from 0.4 +/- 0.2 mm in native to 0.23 +/- 0.07 mm in reinforced veins (p = 0.03). Mesh tube constricted varicose veins were used as bypass material in 11 infrainguinal reconstructions. All grafts were well calibrated at control angiography. External constriction by mesh tubes is a means to convert varicose veins into suitable bypass grafts. PMID:1950138

  6. The effect of pulsatile cardiopulmonary bypass on lung function in elderly patients

    Engels, Gerwin E.; Dodonov, Mikhail; Rakhorst, Gerhard; van Oeveren, Willem; Milano, Aldo D.; Gu, Y. John; Faggian, Giuseppe

    2014-01-01

    Purpose: Cardiopulmonary bypass is still a major cause of lung injury and delay in pulmonary recovery after cardiac surgery. Although it has been shown that pulsatile flow induced by intra-aortic balloon pumping is beneficial for preserving lung function, it is not clear if the same beneficial effec

  7. Structure-function analysis of ribonucleotide bypass by B family DNA replicases

    Clausen, Anders R.; Murray, Michael S.; Passer, Andrew R.; Pedersen, Lars C.; Kunkel, Thomas A. [NIH

    2013-11-01

    Ribonucleotides are frequently incorporated into DNA during replication, they are normally removed, and failure to remove them results in replication stress. This stress correlates with DNA polymerase (Pol) stalling during bypass of ribonucleotides in DNA templates. Here we demonstrate that stalling by yeast replicative Pols δ and ε increases as the number of consecutive template ribonucleotides increases from one to four. The homologous bacteriophage RB69 Pol also stalls during ribonucleotide bypass, with a pattern most similar to that of Pol ε. Crystal structures of an exonuclease-deficient variant of RB69 Pol corresponding to multiple steps in single ribonucleotide bypass reveal that increased stalling is associated with displacement of Tyr391 and an unpreferred C2´-endo conformation for the ribose. Even less efficient bypass of two consecutive ribonucleotides in DNA correlates with similar movements of Tyr391 and displacement of one of the ribonucleotides along with the primer-strand DNA backbone. These structure–function studies have implications for cellular signaling by ribonucleotides, and they may be relevant to replication stress in cells defective in ribonucleotide excision repair, including humans suffering from autoimmune disease associated with RNase H2 defects.

  8. Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger with Bypass Setpoint Temperature Control

    Ungar, Eugene K.

    2008-01-01

    Spacecraft radiators are sized for their maximum heat load in their warmest thermal environment, but must operate at reduced heat loads and in colder environments. For systems where the radiator environment can be colder than the working fluid freezing temperature, radiator freezing becomes an issue. Radiator freezing has not been a major issue for the Space Shuttle and the International Space Station (ISS) active thermal control systems (ATCSs) because they operate in environments that are warm relative to the freezing point of their external coolants (Freon-21 and ammonia, respectively). For a vehicle that lands at the Lunar South Pole, the design thermal environment is 215K, but the radiator working fluid must also be kept from freezing during the 0 K sink of transit. A radiator bypass flow control design such as those used on the Space Shuttle and ISS requires more than 30% of the design heat load to avoid radiator freezing during transit - even with a very low freezing point working fluid. By changing the traditional ATCS architecture to include a regenerating heat exchanger inboard of the radiator and by using a regenerator bypass flow control valve to maintain system setpoint, the required minimum heat load can be reduced by more than half. This gives the spacecraft much more flexibility in design and operation. The present work describes the regenerator bypass ATCS setpoint control methodology. It includes analytical results comparing the performance of this system to the traditional radiator bypass system. Finally, a summary of the advantages of the regenerator bypass system are presented.

  9. Postoperative cognitive deficit after cardiopulmonary bypass with preserved cerebral oxygenation: a prospective observational pilot study

    Meybohm Patrick

    2011-03-01

    Full Text Available Abstract Background Neurologic deficits after cardiac surgery are common complications. Aim of this prospective observational pilot study was to investigate the incidence of postoperative cognitive deficit (POCD after cardiac surgery, provided that relevant decrease of cerebral oxygen saturation (cSO2 is avoided during cardiopulmonary bypass. Methods cSO2 was measured by near infrared spectroscopy in 35 patients during cardiopulmonary bypass. cSO2 was kept above 80% of baseline and above 55% during anesthesia including cardiopulmonary bypass. POCD was tested by trail making test, digit symbol substitution test, Ray's auditorial verbal learning test, digit span test and verbal fluency test the day before and 5 days after surgery. POCD was defined as a decline in test performance that exceeded - 20% from baseline in two tests or more. Correlation of POCD with lowest cSO2 and cSO2 - threshold were determined explorative. Results POCD was observed in 43% of patients. Lowest cSO2 during cardiopulmonary bypass was significantly correlated with POCD (p = 0.015, r2 = 0.44, without Bonferroni correction. A threshold of 65% for cSO2 was able to predict POCD with a sensitivity of 86.7% and a specificity of 65.0% (p = 0.03, without Bonferroni correction. Conclusions Despite a relevant decrease of cerebral oxygen saturation was avoided in our pilot study during cardiopulmonary bypass, incidence of POCD was comparable to that reported in patients without monitoring. A higher threshold for cSO2 may be needed to reduce the incidence of POCD.

  10. [Experimental evaluation of respiratory assist and hemodynamic changes by veno-venous bypass].

    Shimizu, A

    1989-06-01

    The veno-venous bypass (VVB) with a membrane lung is one of the effective procedures to provide respiratory assistance even in patients with a high mortality rate when assisted only with mechanical ventilation. The purpose of this experimental study was to reveal the efficacy of respiratory assistance and the hemodynamic changes by VVB in acute respiratory failure. VVB was carried out in 22 mongrel dogs with acute respiratory failure induced by intratracheal seawater infusion. The ventilation-perfusion ratio (V/Q) of a membrane lung was changed to 1.0, 2.0 and 3.0 for each of the bypass flow rates of 20%, 40%, 60% and 80% of pre-perfusion cardiac output. For each condition variables indicating blood gas status and hemodynamic parameters were measured. As the indicator evaluating the efficiency of CO2 removal by VVB, the index of VVBCO2R was used, indicating the blood CO2 tension differences between IVC and the pulmonary artery. Arterial oxygen saturation was increased with bypass flow rates greater than 60% compared with pre-VVB, but the change was not marked. VVB was considered to be inadequate as a method of oxygenation. Besides, oxygenation was not able to be controlled by changing V/Q. However, significant reduction of arterial CO2 tension (PaCO2) could be obtained even with a bypass flow rate of 20%. As the blood flow rate increased, PaCO2 was lowered. But no more significant reductions of PaCO2 were obtained even with the flow rate of 60% and 80%. VVBCO2R was increased by changing the bypass flow rate from 20% to 40%, while no further increases were observed even with changes from 40% to 60% and 80%.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2509600

  11. Effects of massage therapy on sleep quality after coronary artery bypass graft surgery

    Flavia Baggio Nerbass

    2010-01-01

    Full Text Available INTRODUCTION: Having poor sleep quality is common among patients following cardiopulmonary artery bypass graft surgery. Pain, stress, anxiety and poor sleep quality may be improved by massage therapy. OBJECTIVE: This study evaluated whether massage therapy is an effective technique for improving sleep quality in patients following cardiopulmonary artery bypass graft surgery. METHOD: Participants included cardiopulmonary artery bypass graft surgery patients who were randomized into a control group and a massage therapy group following discharge from the intensive care unit (Day 0, during the postoperative period. The control group and the massage therapy group comprised participants who were subjected to three nights without massage and three nights with massage therapy, respectively. The patients were evaluated on the following mornings (i.e., Day 1 to Day 3 using a visual analogue scale for pain in the chest, back and shoulders, in addition to fatigue and sleep. Participants kept a sleep diary during the study period. RESULTS: Fifty-seven cardiopulmonary artery bypass graft surgery patients were enrolled in the study during the preoperative period, 17 of whom were excluded due to postoperative complications. The remaining 40 participants (male: 67.5%, age: 61.9 years ± 8.9 years, body mass index: 27.2 kg/m² ± 3.7 kg/m² were randomized into control (n = 20 and massage therapy (n = 20 groups. Pain in the chest, shoulders, and back decreased significantly in both groups from Day 1 to Day 3. The participants in the massage therapy group had fewer complaints of fatigue on Day 1 (p=0.006 and Day 2 (p=0.028 in addition, they reported a more effective sleep during all three days (p=0.019 when compared with the participants in the control group. CONCLUSION: Massage therapy is an effective technique for improving patient recovery from cardiopulmonary artery bypass graft surgery because it reduces fatigue and improves sleep.

  12. Evaluation of aortocoronary bypass graft patency by x-ray computed tomography

    The patency of aortocoronary (AC) bypass grafts was evaluated by X-ray computed tomography (CT) in 25 patients and the results were compared with the findings of selective bypassgraphy (SBG). Cardiac CT images were taken from aortic arch to cardiac apex with scanning time of 9 seconds and slice width of 5 or 10 mm. For contrast enhancement (CE), 220 ml of 30 % meglumine iothalamate was administered with intravenous drip infusion : 110 ml as an initial loading dose and 110 ml as a subsequent maintenance dose, before and during the scanning respectively. The interpretation of the CT images was made without knowledge of the SBG results. When the increment of the CT numbers within the graft with CE was identical with that within the aorta or cardiac chambers (back ground), the graft was defined to be patent by CT, otherwise to be occluded. Forty-four of 48 grafts (91.7 %) could be detected by CT and their patency assessed with CE was coincident with the SBG diagnoses (42 patent, 2 occluded). Four grafts (8.3 %) could not be detected by CT : two grafts were patent and another two were occluded by SBG. In one patient, that had received an AC bypass graft on his left anterior descending artery two years before and had begun to have exertional angina again, the increment of the CT number within the graft was about half of that within the back ground ; suggesting a significant bypass flow reduction. In conclusion, CT proved to be a promising noninvasive method for the recognition of AC bypass grafts and for the evaluation of their patency. The possibility of this procedure for the quantitative detection of the bypass flow was also suggested. (author)

  13. Does Off-Pump Coronary Artery Bypass Grafting Negatively Impact Long-Term Survival and Freedom from Reintervention?

    Raja, Shahzad G.; Husain, Mubassher; Popescu, Florentina L.; Chudasama, Dimple; Daley, Siobhan; Amrani, Mohamed

    2013-01-01

    Recently published evidence has raised concerns about worse late mortality and increasing need for reintervention after off-pump coronary artery bypass grafting. We undertook this study to assess the impact of off-pump coronary artery bypass grafting on survival and freedom from reintervention at 10 years. From January 2002 to December 2002, 307 consecutive patients who had isolated multivessel off-pump coronary artery bypass grafting at our institution were compared to a control group of 397 patients that underwent multivessel on-pump coronary artery bypass grafting during the same period. In addition, univariate and risk-adjusted comparisons between the two groups were performed at 10 years. Kaplan-Meier survival was similar for the two cohorts. After adjusting for clinical covariates, off-pump coronary artery bypass grafting did not emerge as a significant independent predictor of long-term mortality (Hazard Ratio 0.91; 95% Confidence Interval 0.70–1.12), readmission to hospital for cardiac cause (Hazard Ratio 0.96; 95% Confidence Interval 0.78–1.10), or the need for reintervention (Hazard Ratio 0.93; 95% Confidence Interval 0.87–1.05). Off-pump coronary artery bypass grafting compared with on-pump coronary artery bypass grafting does not adversely impact survival or freedom from reintervention at a 10-year follow-up. PMID:24106710

  14. Does Off-Pump Coronary Artery Bypass Grafting Negatively Impact Long-Term Survival and Freedom from Reintervention?

    Shahzad G. Raja

    2013-01-01

    Full Text Available Recently published evidence has raised concerns about worse late mortality and increasing need for reintervention after off-pump coronary artery bypass grafting. We undertook this study to assess the impact of off-pump coronary artery bypass grafting on survival and freedom from reintervention at 10 years. From January 2002 to December 2002, 307 consecutive patients who had isolated multivessel off-pump coronary artery bypass grafting at our institution were compared to a control group of 397 patients that underwent multivessel on-pump coronary artery bypass grafting during the same period. In addition, univariate and risk-adjusted comparisons between the two groups were performed at 10 years. Kaplan-Meier survival was similar for the two cohorts. After adjusting for clinical covariates, off-pump coronary artery bypass grafting did not emerge as a significant independent predictor of long-term mortality (Hazard Ratio 0.91; 95% Confidence Interval 0.70–1.12, readmission to hospital for cardiac cause (Hazard Ratio 0.96; 95% Confidence Interval 0.78–1.10, or the need for reintervention (Hazard Ratio 0.93; 95% Confidence Interval 0.87–1.05. Off-pump coronary artery bypass grafting compared with on-pump coronary artery bypass grafting does not adversely impact survival or freedom from reintervention at a 10-year follow-up.

  15. Simple hyperaemia test as a screening method in the postoperative surveillance of infrainguinal in situ vein bypasses

    Nielsen, Tina G; Sillesen, H; Schroeder, T V

    1995-01-01

    follow-up. CONCLUSIONS: Single point waveform analysis of vein bypass velocity profile at rest and during reactive hyperaemia is a simple screening method providing diagnostic and prognostic information which may be of value in the postoperative surveillance of infrainguinal vein bypasses........ The optimal value of the waveform parameters for discrimination between bypasses with and without evidence of stenoses was determined by receiver operating characteristics (ROC) analysis. MAIN RESULTS: Complete Duplex scanning of the entire graft revealed an increase in the peak systolic velocity by a...

  16. Investigation of the excluded stomach after Roux-en-Y gastric bypass: The role of percutaneous endoscopy

    Kanwar RS Gill; J Mark McKinney; Mark E Stark; Ernest P Bouras

    2008-01-01

    Accessing the bypassed portion of the stomach via conventional endoscopy is difficult following Roux-en-Y gastric bypass surgery. However, endoscopic examination of the stomach and small bowel is possible through percutaneous access into the bypassed stomach (BS) with a combined radiologic and endoscopic technique. We present a case of obscure overt gastrointestinal (GI) bleeding where the source of bleeding was thought to be from the BS. After conventional endoscopic methods failed to examine the BS, percutaneous endoscopy (PE) was used as an alternative to surgical exploration.

  17. The management of impending myocardial infarction using coronary artery by-pass grafting and an intra-aortic balloon pump.

    Harris, P L; Woollard, K; Bartoli, A; Makey, A R

    1980-01-01

    Of 33 patients with impending myocardial infarction 25 were treated using a combination of coronary artery by-pass grafting and intra-aortic balloon pumping. Eight patients were treated with coronary artery by-pass grafting alone. Twenty-two of the 25 patients who were treated with the combined technique made a full recovery. Three patients sustained definite myocardial infarctions and one of these died. Five of the 8 patients treated by grafting alone suffered infarction and of these 3 died. The value of intra-aortic balloon pumping in combination with coronary artery by-pass grafting in the management of impending myocardial infarction is discussed. PMID:6968314

  18. Effectiveness and safety of laparoscopic Roux-en-Y gastric bypass for the treatment of type 2 diabetes mellitus

    Zhang, Pin; Zhang, Hongwei; Han, Xiaodong; Di, Jianzhong; Zhou, Yulong; Li, Kun; Zheng, Qi

    2016-01-01

    Gastric bypass may be conducted to aid in glycemic control in adults with type 2 diabetes mellitus (T2DM). The aim of the present study was to investigate the clinical results of diabetes remission and metabolic syndrome in individuals with T2DM after undergoing a gastric bypass. A total of 85 patients (39 men and 46 women) with T2DM underwent laparoscopic Roux-en-Y gastric bypass (LRYGB). Data regarding patient demographics, body mass index (BMI), co-morbidities and details of diabetes melli...

  19. ¿Cambio de paradigma desde el bypass gástrico Roux-en-Y al (mini) bypass gástrico debido a problemas de glucosa?

    Himpens, Jaques

    2014-01-01

    El bypass gástrico Roux-en-Y funciona de la siguiente manera sobre la diabetes mellitus tipo 2: En obesos mórbidos la diabetes tipo2 inicia con la presencia de resistencia a la insulina con un incremento del péptido C, o sea incremento de las necesidades de insulina que los no obesos tienen para mantener el estado euglucemico. Cuando la secreción de insulina es insuficiente, se desarrolla la diabetes. Esta secreción de insulina está modulada por las incretinas y posiblemente por anti-incretin...

  20. Intraoperative conversion to on-pump coronary artery bypass grafting is independently associated with higher mortality in patients undergoing off-pump coronary artery bypass grafting: A propensity-matched analysis

    Deepak Prakash Borde; Balaji Asegaonkar; Pramod Apsingekar; Sujeet Khade; Savni Futane; Bapu Khodve; Ajita Annachhatre; Manish Puranik; Sayaji Sargar; Yogesh Belapurkar; Anand Deodhar; Antony George; Shreedhar Joshi

    2016-01-01

    Context: One of the main limitations of off-pump coronary artery bypass grafting (OPCAB) is the occasional need for intraoperative conversion (IOC) to on-pump coronary artery bypass grafting. IOC is associated with a significantly increased risk of mortality and postoperative morbidity. The impact of IOC on outcome cannot be assessed by a randomized control design. Aims: The objective of this study was to analyze the incidence, risk factors, and impact of IOC on the outcome in patients underg...

  1. A brief study of the effects of turbofan-engine bypass ratio on short and long haul cruise aircraft

    Keith, A. L., Jr.

    1975-01-01

    A brief study of the effects of turbofan-engine bypass ratio on Breguet cruise range and take-off distance for subsonic cruise aircraft showed significant differences between short- and long-haul aircraft designs. Large thrust lapse rates at high bypass ratios caused severe reductions in cruise range for short-haul aircraft because of increases in propulsion system weight. Long-haul aircraft, with a higher fuel fraction (ratio of propulsion weight plus total fuel weight to gross take-off weight), are less sensitive to propulsion-system weight and, accordingly, were not significantly affected by bypass-ratio variations. Both types of aircraft have shorter take-off distances at higher bypass ratios because of higher take-off thrust-weight ratios.

  2. Imaging findings of myocardial revascularization at multidetector computed tomography: where are the bypass grafts?: an iconographic essay

    Multidetector coronary computed tomography angiography is a precise method for evaluating post-coronary revascularization arterial and venous bypass grafts, and is somehow superseding coronary catheterization that is an invasive and more expensive technique. The present iconographic essay is aimed at anatomically demonstrating the bypass grafts most frequently utilized, how to differentiate between arterial and venous grafts and how to find them. The studies were performed in 64-row multidetector computed tomography equipment, with breath hold, controlled heart rate and appropriate protocols with later MPR, MIP and 3D reconstructions according to electrocardiogram. The localization of the bypass grafts and anastomoses at computed tomography studies focused on chest and coronary arteries may represent a difficulty in the images analysis by the radiologist who is not familiar with the matter, so the knowledge of the surgical techniques adopted and possible courses of the saphenous bypass grafts and arterial grafts can aid in the analysis of both studies, avoiding diagnostic errors. (author)

  3. Determination of fit-up stresses in the recirculation bypass line in the Brunswick 1 Reactor

    The report describes the execution of a strain gage plan to determine fit-up stress levels in a bypass line in the recirculation system of a boiling water reactor. In addition to the experimental work, an analysis method is developed to determine the forces and moment acting throughout the line using the results from a limited number of strain gage locations. The general level of stress measured and calculated in the line was low. The peak axial strain measured with strain gages gave a tensile stress of 2.3 ksi at the outlet-side weldolet. The analysis showed that the maximum calculated axial stress in the line occurred at the inlet-side elbow with a magnitude of 4.3 ksi. This level of stress is the sum of construction fit-up and dead weight and is not significant when compared with total stress levels in BWR bypass lines from service-induced and residual welding stresses

  4. Indus-1 LCW plant control system using reconfigurable logic and timed interlock bypass

    Low Conductivity Water (LCW) is used for cooling of various accelerator components in Booster and Indus-1. This plant uses ten interlocks for protection of major components such as primary side pumps, secondary side pumps and cooling tower pumps. The paper presents the architecture and scheme of microcontroller based interlock card with configurable logic and timed bypass features. For communication and in-system configuration of the card, MODBUS protocol is implemented in software. The card is designed to guarantee the failsafe condition of interlock in case any active component fails. The card will enhance the system availability by avoiding the manual faults during the system maintenance. It also alarms about the temporary bypassing of interlocks and provides flexibility to the operator for changing interlock logic. (author)

  5. Red Kidney: Kidney Transplant From a Deceased Donor Who Received Massive Blood Transfusion During Cardiopulmonary Bypass.

    Bell, Richard; Hanif, Faisal; Prasad, Padmini; Ahmad, Niaz

    2016-06-01

    Here, we present a case of a deceased-donor kidney transplant. The brain-dead donor had received a massive blood transfusion during cardiopulmonary bypass, which lead to hemolysis, hemoglobinuria, acute kidney injury, and renal replacement therapy. The kidney appeared red after in situ flush. Postoperatively, the recipient developed delayed graft function. Protocol biopsy during the postoperative period revealed the widespread deposition of heme pigment in the renal tubules. Massive blood transfusion and cardiopulmonary bypass surgery are associated with hemolysis and heme pigment deposition in the renal tubules, which subsequently lead to acute kidney injury. Kidneys from such donors appear red and, while this does not preclude transplant, are likely to develop delayed graft function. PMID:26030717

  6. Steady-state, whole-core prismatic VHTR simulation including core bypass

    The neutron transport code DeCART and the commercial CFD code STAR-CD are being integrated into the SHARP reactor analysis tool-kit to enable the extension of it's capabilities to high-fidelity analysis of prismatic VHTR cores. The studies described herein provide a preliminary evaluation of the applicability of RANS-based CFD methods to the prediction of fluid flow and heat transfer within a large symmetric region of a VHTR core. Simulations considering a single flow channel define mesh density requirements and quantify impacts of detailed geometric details on turbulent flow development. Simulations of a single column of blocks identify the need for detailed power distributions and for including the bypass flow between columns of blocks in full core simulations. While additional development of the meshing strategy and tools is needed, a coarse mesh simulation of a 116. segment of a VHTR core with bypass flow provides a preliminary demonstration of applicability. (authors)

  7. By-pass Devices as Effective Means of Protection from the Hydraulic Hammer

    Khalid S. Al-Rababa

    2005-01-01

    Full Text Available Switching-off the parallel working pump units causes sudden discharge changes in parallel pipe lines, as a result of that hydraulic shocks takes place. The damping of these shocks can be achieved by the installation of the by-pass devices between the parallel lines of the piping system. The analytical calculations demonstrate that the reduction in hydraulic shocks reaches 40% and considerable part of the electric power (from 5 up to 21% is economized by using the by-pass devices, the duration of pressure decline decreases by more than 1,5 times. Comparison of the calculations based on the developed algorithm with the results of practical studies at the pumping station (Syrdarya has shown good convergence of analytical and experimental outcomes.

  8. The Effect of Magnetohydrodynamic (MHD) Energy Bypass on Specific Thrust for a Supersonic Turbojet Engine

    Benyo, Theresa L.

    2010-01-01

    This paper describes the preliminary results of a thermodynamic cycle analysis of a supersonic turbojet engine with a magnetohydrodynamic (MHD) energy bypass system that explores a wide range of MHD enthalpy extraction parameters. Through the analysis described here, it is shown that applying a magnetic field to a flow path in the Mach 2.0 to 3.5 range can increase the specific thrust of the turbojet engine up to as much as 420 N/(kg/s) provided that the magnitude of the magnetic field is in the range of 1 to 5 Tesla. The MHD energy bypass can also increase the operating Mach number range for a supersonic turbojet engine into the hypersonic flight regime. In this case, the Mach number range is shown to be extended to Mach 7.0.

  9. Bypass Diode Temperature Tests of a Solar Array Coupon Under Space Thermal Environment Conditions

    Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon

    2016-01-01

    Tests were performed on a 56-cell Advanced Triple Junction solar array coupon whose purpose was to determine margin available for bypass diodes integrated with new, large multi-junction solar cells that are manufactured from a 4-inch wafer. The tests were performed under high vacuum with coupon back side thermal conditions of both cold and ambient. The bypass diodes were subjected to a sequence of increasing discrete current steps from 0 Amp to 2.0 Amp in steps of 0.25 Amp. At each current step, a temperature measurement was obtained via remote viewing by an infrared camera. This paper discusses the experimental methodology, experiment results, and the thermal model.

  10. Neuropsychological dynamics in patients with type 2 diabetes mellitus undergone coronary artery bypass grafting

    Ol'ga Aleksandrovna Trubnikova

    2012-12-01

    Full Text Available Aim. The study was aimed at evaluation of hospital neuropsychological dynamics in ischemic heart disease patients with comorbid type 2 diabetes mellitus (T2DM undergone on-pump coronary artery bypass grafting.Materials and methods. 14 from a total of 37 examined patients had T2DM. Diabetic patients were found to have lower attention parameters prior to the intervention in comparison to non-diabetic controls. At days 7-10 after the surgery all patients demonstrated deterioration of cognitive functions.Results. We observed deeper deterioration in diabetic patients, regarding attention, memory, sensorimotor speed and quantity of erroneous test responses, as measured against individuals with normal glucose tolerance.Conclusion. Diabetic patients undergone coronary artery bypass surgery show lower cognitive characteristics when compared to controls without T2DM, suggesting this cohort to be a high-risk group for further cognitive decline.

  11. The increase of plasminogen activator inhibitor activity is associated with graft occlusion in patients undergoing aorto-coronary bypass surgery

    Rifon, J. (José); Paramo, J. A.; Panizo, C. (Carlos); R. Montes; Rocha, E

    1997-01-01

    Early graft occlusion is a common complication in patients undergoing aorto-coronary bypass surgery. Both mechanical and haemostatic factors play a role in the pathogenesis of thrombotic occlusion. Several studies have demonstrated a relationship between fibrinolytic activity and venous or arterial thrombosis. We undertook this study to evaluate the possible contribution of the fibrinolytic system to postoperative occlusion in patients undergoing aorto-coronary bypass graft (CABG). A venous o...

  12. Oxidative Stress and Homocysteine Metabolism Following Coronary Artery Bypass Grafting by On-pump and Off-pump Techniques

    Susan Hassanzadeh Salmasi; Mohammad Rahbani Noubar; Rezayat Parvizi

    2007-01-01

    Background: It is well documented that coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) causes ischemia and oxidative stress of the whole body. To compare the effect of on – pump and off –pump CABG on the induction of the oxidative stress and the metabolism of homocysteine which is involved in the synthesis of glutathione was investigated in the CABG patients during the early postoperative period.Methods: Plasma homocysteine, folate total antioxidant capacity (TAC) and...

  13. Effect of trimetazidine and glucose- insulin-potassium use on myocard during beating heart coronary artery bypass surgery

    Ercan, Abdulkadir; Velioğlu, Yusuf; Ercan, Arzu; Gürbüz, Orçun; Özkan, Hakan; Karal, İlker Hasan; Biçer, Murat; Ener, Serdar

    2011-01-01

    Objectives: This prospective, randomised, controlled, clinical study was planned to determine the effect of trimetazidine and glucose - insulin - potassium (GIK) on myocardial ischemia-rep­erfusion during beating heart coronary artery bypass surgery. Materials and methods: Patients (n=45) with coronary artery disease who required beating heart coronary artery bypass grafting were randomly allocated into three groups. Patients in group 1 (n=15) was recevied trimetazidine (20 mg x 3...

  14. Effect of trimetazidine and glucose- insulin-potassium use on myocard during beating heart coronary artery bypass surgery

    Abdulkadir Ercan; Yusuf Velioğlu; Arzu Ercan; Orçun Gürbüz; Hakan Özkan; İlker Hasan Karal; Murat Biçer; Serdar Ener

    2011-01-01

    Objectives: This prospective, randomised, controlled, clinical study was planned to determine the effect of trimetazidine and glucose - insulin - potassium (GIK) on myocardial ischemia-reperfusion during beating heart coronary artery bypass surgery.Materials and methods: Patients (n=45) with coronary artery disease who required beating heart coronary artery bypass grafting were randomly allocated into three groups. Patients in group 1 (n=15) was recevied trimetazidine (20 mg x 3 per day) 7 da...

  15. Metoprolol treatment for two years after coronary bypass grafting: effects on exercise capacity and signs of myocardial ischaemia.

    Sjöland, H.; Caidahl, K; Lurje, L.; Hjalmarson, A.; Herlitz, J

    1995-01-01

    OBJECTIVE--To evaluate whether prophylactic treatment with metoprolol for two years after coronary artery bypass grafting improves working capacity and reduces the occurrence of myocardial ischaemia in patients with coronary artery disease. METHODS--After coronary artery bypass grafting, patients were randomised to treatment with metoprolol or placebo for two years. Two years after randomisation, a computerised 12-lead electrocardiogram was obtained during a standardised bicycle exercise test...

  16. Compromised Cardiopulmonary Exercise Capacity in Patients Early After Endoscopic Atraumatic Coronary Artery Bypass Graft: Implications for Rehabilitation

    Hansen, Dominique; Roijackers, Ruben; Jackmaert, Lore; Robic, Boris; Hendrikx, Marc; Yilmaz, Alaaddin; Frederix, Ines; Rosseel, Michael; DENDALE, PAUL

    2016-01-01

    Objective: The purpose of this work was to test the hypothesis that cardiopulmonary exercise tolerance is better preserved early after endoscopic atraumatic coronary artery bypass graft (endo-ACAB) surgery versus coronary artery bypass graft (CABG) surgery. Design: Twenty endo-ACAB surgery patients, 20 CABG surgery patients, and 15 healthy subjects executed a maximal cardiopulmonary exercise test, with assessment and comparison of cycling power output, O2 uptake, CO2 output, respiratory ...

  17. Does transfusion of residual cardiopulmonary bypass circuit blood increase postoperative bleeding? A prospective randomized study in patients undergoing on pump cardiopulmonary bypass

    Duara Rajnish

    2008-01-01

    Full Text Available Objective: Homologous blood transfusion after open heart surgery puts a tremendous load on the blood banks. This prospective randomized study evaluates the efficacy of infusing back residual cardiopulmonary bypass (CPB circuit i.e., pump blood as a means to reduce homologous transfusion after coronary artery bypass surgery (CABG and whether its use increases postoperative drainage. Materials and Methods: Sixty-seven consecutive patients who underwent elective CABGs under CPB were randomized into 2 groups: (1 cases where residual pump blood was used and (2 controls where residual pump blood was not used. Patients were monitored for hourly drainage on the day of surgery and the 1 st postoperative day and the requirements of homologous blood and its products. Data were matched regarding change in Hemoglobin, Packed Cell Volume and coagulation parameters till 1st postoperative day. All cases were followed up for three years. Results: There was a marginal reduction in bleeding pattern in the early postoperative period in the cases compared to controls. The requirement of homologous blood and its products were also reduced in the cases. Conclusions: The use of CPB circuit blood is safe in the immediate postoperative period. The requirement of homologous blood transfusion can come down if strict transfusion criteria are maintained.

  18. Postoperative ventilatory and circulatory effects of heating after aortocoronary bypass surgery. Extended rewarming during cardiopulmonary bypass and postoperative radiant heat supply.

    Joachimsson, P O; Nyström, S O; Tydén, H

    1987-08-01

    Twenty-four patients with stable angina pectoris were studied after aortocoronary bypass surgery with hypothermic cardiopulmonary bypass (CPB). Twelve patients (radiant heat supply group) were rewarmed during CPB to a nasopharyngeal temperature of at least 38 degrees C and a mean rectal temperature of 34.4 degrees C. Postoperatively they received radiant heat supply from a thermal ceiling. In addition, a heating water mattress was used during the end of the operation and heated, humidified inspired gases were administered intra- and postoperatively. The other 12 patients (combination heat supply group) had the rewarming during CPB extended until the rectal temperature exceeded 36 degrees C, but otherwise received the same treatment as the radiant heat supply group. The combination of extended rewarming during CPB and postoperative radiant heat supply significantly reduced oxygen uptake, carbon dioxide production and the required ventilation volumes during early recovery as compared with the values in the radiant heat supply group. The reduced metabolic demands were accompanied by lower cardiac index and oxygen delivery, which, however, were sufficient for adequate tissue perfusion as judged by the similarity in oxygen extraction and arterial base excess values in the two groups. The metabolic demands and ventilatory requirements were reduced to a level at which safe early extubation is possible. PMID:3498281

  19. Shape design by optimal flow control and reduced basis techniques: applications to bypass configurations in haemodynamics

    Rozza, Gianluigi; Quarteroni, Alfio

    2007-01-01

    The purpose of this thesis is to develop numerical methods for optimization, control and shape design in computational fluid dynamics, more precisely in haemodynamics. The application studied is related with the shape optimization of an aorto-coronaric bypass. The optimization process has to keep into account aspects which are very different and sometimes conflicting, for this reason the process has been organized in more levels dealing with a geometrical scale. Moreover we have chosen to use...

  20. Experimental study of the wall-friction development during boundary layer by-pass transition

    Jonáš, Pavel; Mazur, Oton; Uruba, Václav

    Praha : Ústav termomechaniky AV ČR, 2006 - (Jonáš, P.; Uruba, V.), s. 67-70 ISBN 80-87012-01-1. [Colloquium Fluid Dynamics 2006. Praha (CZ), 25.10.2006-27.10.2006] R&D Projects: GA AV ČR(CZ) IAA200760614 Institutional research plan: CEZ:AV0Z20760514 Keywords : by-pass transition * wall-friction intermittency * conditioned averaging Subject RIV: BK - Fluid Dynamics