Renal Arteriovenous Shunts: Clinical Features, Imaging Appearance, and Transcatheter Embolization Based on Angioarchitecture.

Science.gov (United States)

Maruno, Miyuki; Kiyosue, Hiro; Tanoue, Shuichi; Hongo, Norio; Matsumoto, Shunro; Mori, Hiromu; Sagara, Yoshiko; Kashiwagi, Junji

2016-01-01

Renal arteriovenous (AV) shunt, a rare pathologic condition, is divided into two categories, traumatic and nontraumatic, and can cause massive hematuria, retroperitoneal hemorrhage, pain, and high-output heart failure. Although transcatheter embolization is a less-invasive and effective treatment option, it has a potential risk of complications, including renal infarction and pulmonary embolism, and a potential risk of recanalization. The successful embolization of renal AV shunt requires a complete occlusion of the shunted vessel while preventing the migration of embolic materials and preserving normal renal arterial branches, which depends on the selection of adequate techniques and embolic materials for individual cases, based on the etiology and imaging angioarchitecture of the renal AV shunts. A classification of AV malformations in the extremities and body trunk could precisely correspond with the angioarchitecture of the nontraumatic renal AV shunts. The selection of techniques and choice of adequate embolic materials such as coils, vascular plugs, and liquid materials are determined on the basis of cause (eg, traumatic vs nontraumatic), the classification, and some other aspects of the angioarchitecture of renal AV shunts, including the flow and size of the fistulas, multiplicity of the feeders, and endovascular accessibility to the target lesions. Computed tomographic angiography and selective digital subtraction angiography can provide precise information about the angioarchitecture of renal AV shunts before treatment. Color Doppler ultrasonography and time-resolved three-dimensional contrast-enhanced magnetic resonance angiography represent useful tools for screening and follow-up examinations of renal AV shunts after embolization. In this article, the classifications, imaging features, and an endovascular treatment strategy based on the angioarchitecture of renal AV shunts are described. (©)RSNA, 2016.

Differential kinetics of response and toxicity using stereotactic radiation and interventional radiological coiling for pulmonary arterio-venous shunting from metastatic leiomyosarcoma

International Nuclear Information System (INIS)

Wong, Annie Ngai Man; Siva, Shankar; Chin, Kwang; Manser, Renee; Antippa, Phillip; Dowling, Richard; Mileshkin, Linda Rose

2015-01-01

Case report demonstrating the differential kinetics of response and toxicity using stereotactic radiation and interventional radiological coiling for pulmonary arterio-venous shunting from leiomyosarcoma pulmonary metastases.

A femoral arteriovenous shunt facilitates arterial whole blood sampling in animals

International Nuclear Information System (INIS)

Weber, Bruno; Burger, Cyrill; Buck, Alfred; Biro, Peter

2002-01-01

In this study we evaluated on-line continuous blood sampling in a femoral arteriovenous (a-v) shunt for use in quantitative tracer studies using gamma-emitting radionuclides in animals. The shunt consisted of 40 cm polyethylene tubing (PE-50) guided through a coincidence probe. Two three-way valves allowed blood pressure measurements and tracer injection. Blood flow in the shunt and the impulse response function (IRF) were assessed using heparinized human blood mixed with fluorine-18 fluorodeoxyglucose (FDG). In vivo experiments were performed in eight male rats (300-350 g) anaesthetized with halothane. In three rats, manual blood sampling was performed in parallel with on-line sampling. In another five animals, the arterial whole blood activity was recorded on-line for 40 min. For the experiments 150-180 MBq FDG was injected over 35 s. Blood flow in the shunt was 23.6, 29.2 and 42.8 ml/h at 100, 120 and 160 mmHg, respectively. The IRF was characterized by minimal dispersion (1-2 s FWHM). Deconvolution of the measured arterial input curves with the IRF changed the measured curve only minimally. Whole blood radioactivity concentration derived from manual and on-line sampling were in excellent agreement. The curves derived from on-line sampling were of high statistical quality. In conclusion, a femoral a-v shunt allows multiple manipulations such as measurement of the arterial whole blood activity, continuous blood pressure monitoring, injection of the tracer and collection of blood samples if necessary. It is not associated with blood loss if the collection of blood samples is not required. It is more convenient to use than manual sampling, the peak of the input curve is never missed and the input curves are of high statistical quality. (orig.)

Pulmonary Arteriovenous Fistula: Clinical and Histologic Spectrum of Four Cases

Directory of Open Access Journals (Sweden)

Soomin Ahn

2016-09-01

Full Text Available Pulmonary arteriovenous fistula (PAVF is abnormally dilated vessels that provide a right-to-left shunt between pulmonary artery and pulmonary vein and is clinically divided into simple and complex type. Here, we report four cases of surgically resected sporadic PAVFs presenting various clinical and histologic spectrums. Cases 1 (a 57-old-female and 2 (a 54-old-female presented as incidentally identified single aneurysmal fistulas and the lesions were surgically removed without complication. On the other hand, case 3 (an 11-old-male showed diffuse dilated vascular sacs involving both lungs and caused severe hemodynamic and pulmonary dysfunction. Embolization and surgical resection of the main lesion failed to relieve the symptoms. Case 4 (a 36-old-male had a localized multiloculated cyst clinically mimicking congenital cystic adenomatoid malformation. Microscopically, the lesion consisted of dilated thick vessels, consistent with the diagnosis of fistulous arteriovenous malformation/hemangioma.

Assessment of surgical portosystemic shunts and associated complications: The diagnostic and therapeutic role of radiologists

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Taslakian, Bedros, E-mail: btaslakian@gmail.com [Department of Radiology, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon); Faraj, Walid, E-mail: wf07@aub.edu.lb [Department of General Surgery, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon); Khalife, Mohammad, E-mail: mk12@aub.edu.lb [Department of General Surgery, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon); Al-Kutoubi, Aghiad, E-mail: mk00@aub.edu.lb [Department of Radiology, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon); El-Merhi, Fadi, E-mail: fe19@aub.edu.lb [Department of Radiology, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon); Saade, Charbel, E-mail: cs39@aub.edu.lb [Department of Radiology, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon); Hallal, Ali, E-mail: ah05@aub.edu.lb [Department of General Surgery, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon); Haydar, Ali, E-mail: ah24@aub.edu.lb [Department of Radiology, American University of Beirut Medical Center, Riad El-Solh 1107 2020—PO Box: 11-0236, Beirut (Lebanon)

2015-08-15

Highlights: • Portal hypertension is the pathological increase in portal venous pressure. • Surgical portosystemic shunting is an accepted methods to decrease portal venous pressure. • Surgical portosystemic shunts are divided into selective and nonselective. • Shunt thrombosis is a serious complication, resulting in shunt dysfunction. • Imaging is essential in the assessment of the shunt function and anatomy. - Abstract: Surgical portosystemic shunting, the formation of a vascular connection between the portal and systemic venous circulation, has been used as a treatment to reduce portal venous pressure. Although the use of portosystemic shunt surgery in the management of portal hypertension has declined during the past decade in favour of alternative therapies, and subsequently surgeons and radiologists became less familiar with the procedure, it remains a well-established treatment. Knowledge of different types of surgical portosystemic shunts, their pathophysiology and complications will help radiologists improve communication with surgeons and enhance their understanding of the diagnostic and therapeutic role of radiology in the assessment and management of these shunts. Optimal assessment of the shunt is essential to determine its patency and allow timely intervention. Both non-invasive and invasive imaging modalities complement each other in the evaluation of surgical portosystemic shunts. Interventional radiology plays an important role in the management of complications, such as shunt thrombosis and stenosis. This article describes the various types of surgical portosystemic shunts, explains the anatomy and pathophysiology of these shunts, illustrates the pearls and pitfalls of different imaging modalities in the assessment of these shunts and demonstrates the role of radiologists in the interventional management of complications.

Assessment of surgical portosystemic shunts and associated complications: The diagnostic and therapeutic role of radiologists

International Nuclear Information System (INIS)

Taslakian, Bedros; Faraj, Walid; Khalife, Mohammad; Al-Kutoubi, Aghiad; El-Merhi, Fadi; Saade, Charbel; Hallal, Ali; Haydar, Ali

2015-01-01

Highlights: • Portal hypertension is the pathological increase in portal venous pressure. • Surgical portosystemic shunting is an accepted methods to decrease portal venous pressure. • Surgical portosystemic shunts are divided into selective and nonselective. • Shunt thrombosis is a serious complication, resulting in shunt dysfunction. • Imaging is essential in the assessment of the shunt function and anatomy. - Abstract: Surgical portosystemic shunting, the formation of a vascular connection between the portal and systemic venous circulation, has been used as a treatment to reduce portal venous pressure. Although the use of portosystemic shunt surgery in the management of portal hypertension has declined during the past decade in favour of alternative therapies, and subsequently surgeons and radiologists became less familiar with the procedure, it remains a well-established treatment. Knowledge of different types of surgical portosystemic shunts, their pathophysiology and complications will help radiologists improve communication with surgeons and enhance their understanding of the diagnostic and therapeutic role of radiology in the assessment and management of these shunts. Optimal assessment of the shunt is essential to determine its patency and allow timely intervention. Both non-invasive and invasive imaging modalities complement each other in the evaluation of surgical portosystemic shunts. Interventional radiology plays an important role in the management of complications, such as shunt thrombosis and stenosis. This article describes the various types of surgical portosystemic shunts, explains the anatomy and pathophysiology of these shunts, illustrates the pearls and pitfalls of different imaging modalities in the assessment of these shunts and demonstrates the role of radiologists in the interventional management of complications

Evaluation of radiation dose during the percutaneous angioplasty for arteriovenous shunt assembling

International Nuclear Information System (INIS)

Ting, Chien-Yi; Wu, Wen-Shiann; Tang, Kuo-Ting; Wang, Hsin-Ell; Lin, Chun-Chih

2017-01-01

Percutaneous angioplasty (PTA) for dysfunctional hemodialysis is usually performed by radiologists, but not cardiologists, in Taiwan, so that the radiation dose in patients and physicians are usually unknown and related studies are rare. In this study, we are pioneering an investigation into the radiation dose in percutaneous angioplasty for arteriovenous shunt assembling and the effect of RADPAD device, a lead-free surgical drape containing Bi and Ba, on the decrease of a radiation dose in the non-targeted organs of the patient and also the operator. The radiation dose in a typical digital subtraction angiography (DSA) by the PTA protocol under a fixed field of view (FOV), was measured with optically simulated luminescent dosimeters arranged in a PIXY RS-102 anthropomorphic phantom. The results indicate that there is a significant dose reduction at the hands (0.022±0.002 mGy before treatment vs. 0.014±0.001 mGy after treatment; P=0.021), but not at the lens (0.027±0.003 mGy before treatment vs. 0.018±0.001 mGy after treatment; P=0.058), and the gonads (0.026±0.003 mGy before treatment vs. 0.020±0.001 mGy after treatment; P=0.058), of the cardiologist/operator after treatment with the RADPAD drape. At the patient's abdomen, the dose significantly decreased from 1.597±0.104 mGy to 0.031±0.002 mGy (P<0.001) after treated with the RADPAD shield. For the chest, lens and thyroid in the patient, the doses were respectively 0.154±0.100 mGy (compared to 0.049±0.001 mGy after treated with the RADPAD drape; P=0.0002), 0.066±0.001 mGy (compared to 0.021±0.001 mGy after the RADPAD treatment; P=0.009), and 0.208±0.002 mGy (compared to 0.042±0.003 mGy after shielded with the RADPAD drape; P<0.0001), which represents an apparent reduction in dose. However, no significant difference was found in the dose-area product between before (179.9±0.1mGy.cm 2 ) and after (177.4±0.1mGy.cm 2 ) the treatment (P=0.38). In conclusion, the RADPAD drape significantly reduced

Percutaneous arteriovenous shunting in patients with severe COPD. A new interventional radiological treatment; Perkutane arteriovenoese Shuntanlage bei Patienten mit schwerer COPD. Eine neue interventionelle radiologische Technik

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Schlosser, Thomas; Forsting, M. [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie; Burbelko, M. [Marburg Univ. (Germany). Klinik fuer Strahlendiagnostik; Ulrich, M. [Parkkrankenhaus Leipzig (Germany). Klinik fuer Innere Medizin/Angiologie/Kardiologie; Ludwig, F.; Reutiman, T. [ROX Medical, San Clemente, CA (United States); Antoch, G. [Universitaetsklinikum Duesseldorf (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Adamus, R. [Klinikum Nuernberg Nord (Germany). Inst. fuer Radiologie

2013-03-15

Purpose: The aim of this study was to evaluate the technical feasibility and safety of a new interventional radiological technique to create a shunt percutanously between the external iliac vein and artery in patients with severe COPD. Materials and Methods: 40 patients were included in this multicenter trial. In 38 patients the artery was punctured from the vein using a novel crossing needle. A special delivery system was used to implant a novel nitinol device (ACS, ROX Medical) between the artery and the vein to maintain a 4 mm calibrated and structured fistula between the two vessels. Results: Shunt implantation was successful in 38 patients. The perfused arteriovenous shunts could be well documented in DSA and the diameter was measured between 3 and 4 mm in all cases. Peri-interventional non-flow-limiting dissection of the iliac artery occurred in one patient. Post-interventional venous bleeding in two patients was treated successfully by local compression. In one patient a peripheral artery thrombembolism was successfully treated by thrombolysis. Conclusion: The new interventional radiological technique to create an arteriovenous shunt in the iliac vessels presented in this study has proven to be feasible and safe. (orig.)

Superior vena cava syndrome after pulsatile bidirectional Glenn shunt procedure: Perioperative implications

Directory of Open Access Journals (Sweden)

Neema Praveen

2009-01-01

Full Text Available Bidirectional superior cavopulmonary shunt (bidirectional Glenn shunt is generally performed in many congenital cardiac anomalies where complete two ventricle circulations cannot be easily achieved. The advantages of BDG shunt are achieved by partially separating the pulmonary and systemic venous circuits, and include reduced ventricular preload and long-term preservation of myocardium. The benefits of additional pulsatile pulmonary blood flow include the potential growth of pulmonary arteries, possible improvement in arterial oxygen saturation, and possible prevention of development of pulmonary arteriovenous malformations. However, increase in the systemic venous pressure after BDG with additional pulsatile blood flow is known. We describe the peri-operative implications of severe flow reversal in the superior vena cava after pulsatile BDG shunt construction in a child who presented for surgical interruption of the main pulmonary artery.

Surgical treatment for a complex congenital arteriovenous malformation of the lower limb.

Science.gov (United States)

Ozcan, Ali Vefa; Boysan, Emre; Isikli, Osman Yasar; Goksin, Ibrahim

2013-01-01

Arteriovenous fistula is defined as an abnormal communication between the arterial and venous systems. The complexity of congenital arteriovenous malformations makes treatment challenging. We present the case of a 23-year-old woman who had a complex congenital arteriovenous malformation in her left leg and a history of 2 unsuccessful coil-embolization procedures. We ligated all the feeding arteries of the arteriovenous malformation in the region of the superficial femoral artery, and the surgery was successful without sequelae. The patient returned 2 years later with thrombosis of the great saphenous vein and underwent a second operation. The thrombosed vein and all varicosities were excised successfully. Surgery can be an effective method for correcting complex congenital arteriovenous malformations, especially in the lower limbs. A 2-staged surgical approach like ours might be a good option in suitable patients.

Surgical Outcomes of Ahmed or Baerveldt Tube Shunt Implantation for medically Uncontrolled Traumatic Glaucoma.

Science.gov (United States)

Yadgarov, Arkadiy; Liu, Dan; Crane, Elliot S; Khouri, Albert S

2017-01-01

To describe postoperative surgical success of either Ahmed or Baerveldt tube shunt implantation for eyes with medically uncontrolled traumatic glaucoma. A review was carried out to identify patients with traumatic glaucoma that required tube shunt implantation between 2009 and 2015 at Rutgers University in Newark, New Jersey, USA. Seventeen eyes from 17 patients met inclusion criteria, including at least 3-month postoperative follow-up. The main outcome measure was surgical success at 1-year follow-up after tube implantation. Mean preoperative intraocular pressure (IOP) was 34.1 ± 8.2 mm Hg on 3.1 ± 1.6 ocular hypotensive medications. Nine eyes (53%) sustained closed globe injury. Ten eyes (59%) received an Ahmed valve shunt and seven eyes (41%) received a Baerveldt tube shunt. Surgical success rate at 1 year postoperatively was 83%. Compared to preoperative, the mean postoperative IOP was significantly lower (16.1 ± 3.5 mm Hg, p Ahmed or Baerveldt tube shunt provided successful control of IOP in patients with medically uncontrollable traumatic glaucoma. Yadgarov A, Liu D, Crane ES, Khouri AS. Surgical Outcomes of Ahmed or Baerveldt Tube Shunt Implantation for medically Uncontrolled Traumatic Glaucoma. J Curr Glaucoma Pract 2017;11(1):16-21.

Post V-P shunt surgical site EDH an uncommon complication: case report

Directory of Open Access Journals (Sweden)

Garg Manish

2017-06-01

Full Text Available ventriculoparitoneal shunt is well established modality of treatment for hydrocephalous. Complication of v-p shunt are also mentioned in literature like shunt infection shunt migration etc [8]. Here we are describing a rare complication of vp shunt which barely mentioned in literature. A 22 yr male admitted with complain of headache & vomiting patient was diagnosed to have tubercular meningities with hydrocephalous. Patient planned for ventriculoparietoneal shunt surgery and vp shunt was done. On 3rd post-surgery day patient develop weakness in Left side of body. Urgent ncct head done which showed EDH at surgical site. Immediate craniotomy and evacuation of hematoma was done patient improved and discharged. Thus we are discussing the importance of meticulous surgery for v-p shunt, post op ct scan and treatment.

Outcomes of systemic to pulmonary artery shunts in patients weighing less than 3 kg: analysis of shunt type, size, and surgical approach.

Science.gov (United States)

Myers, John W; Ghanayem, Nancy S; Cao, Yumei; Simpson, Pippa; Trapp, Katie; Mitchell, Michael E; Tweddell, James S; Woods, Ronald K

2014-02-01

To evaluate outcomes of systemic to pulmonary artery shunts (SPS) in patients weighing less than 3 kg with regard to shunt type, shunt size, and surgical approach. Patients weighing less than 3 kg who underwent modified Blalock-Taussig or central shunts with polytetrafluoroethylene grafts at our institution from January 1, 2000, to May 31, 2011, were reviewed. Patients who had undergone other major concomitant procedures were excluded from the analysis. Primary outcomes included mortality (discharge mortality and mortality before next planned palliative procedure or definitive repair), cardiac arrest and/or extracorporeal membrane oxygenation (ECMO), and shunt reintervention. In this cohort of 80 patients, discharge survival was 96% (77/80). Postoperative cardiac arrest or ECMO occurred in 6/80 (7.5%), and shunt reintervention was required in 14/80 (17%). On univariate analysis, shunt reintervention was more common in patients with 3-mm shunts (11/30, 37%) compared with 3.5-mm (2/36, 6%) or 4-mm shunts (1/14, 7%) (P approach and cardiac arrest/ECMO or mortality. Multiple logistic regression demonstrated that a shunt size of 3 mm (P = .019) and extracardiac anomaly (P = .047) were associated with shunt reintervention, whereas no variable was associated with cardiac arrest/ECMO or mortality. In this high-risk group of neonates weighing less than 3 kg at the time of SPS, survival to discharge and the next planned surgical procedure was high. Outcomes were good with the 3.5- and 4-mm shunts; however, shunt reintervention was common with 3-mm shunts. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

A Study on the Measurement of Intrapulmonary Shunt in Liver Diseases by the Nucleolide Method

International Nuclear Information System (INIS)

Yun, Sung Chul; Ahn, Jae Hee; Choi, Soo Bong

1987-01-01

The fact there are increase of intrapulmonary arteriovenous shunt amount in the liver cirrhosis patient has been known since 1950. And the method of shunt amount calculation by radionuclide method using 99m Tc-MAA was introduced in the middle of 1970. We measured intrapulmonary shunt amount by means of perfusion lung scan using 99m Tc-MAA in the various type of liver diseases especially in chronic liver diseases and acute liver disease. The results were as followed. 1) The amount of arteriovenous intrapulmonary shunt in the total case of liver disease was 9.3±3.9%, and that of in the control group was 4.6±2.1%. 2) The amount of arteriovenous intrapulmonary shunt in the chronic liver disease was 10.8±4.4%, and that of in the acute liver disease was 7.2±2.8%. We observed significant differences between normal control group and liver disease group, and between chronic liver disease group and acute liver disease group in the amount of shunt by the nucleolide method.

Surgical management of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb.

Science.gov (United States)

Tirakotai, W; Benes, L; Kappus, C; Sure, U; Farhoud, A; Bien, S; Bertalanffy, H

2007-01-01

Dural arteriovenous fistulas located in the vicinity of the jugular foramen are complex vascular malformations and belong to the most challenging skull base lesions to treat. The authors comprehensively analyze multiple features in a series of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb. Four patients who underwent surgery via the transcondylar approach to treat dural arteriovenous fistulas around the jugular foramen were retrospectively reviewed. Previously, endovascular treatment was attempted in all patients. The success of the surgical treatment was examined with postoperative angiography. Complete obliteration of the dural arteriovenous fistulas (DAVFs) was achieved in three patients, and significant flow reduction in one individual. All patients had a good postoperative outcome, and only one experienced mild hypoglossal nerve palsy. Despite extensive bone drilling, an occipitocervical fusion was necessary in only one patient with bilateral lesions. The use of an individually tailored transcondylar approach to treat dural arteriovenous fistulas at the region of the jugular foramen is most effective. This approach allows for complete obliteration of the connecting arterial feeders, and removal of bony structures containing pathological vessels.

Pulmonale arteriovenøse malformationer, moderne behandlingsprincipper

DEFF Research Database (Denmark)

Andersen, P E; Kjeldsen, A D

2001-01-01

Pulmonary arteriovenous malformations are congenital vascular malformations in the lungs, which act as shunts so that the blood is not oxygenated or filtered. These patients are typically hypoxaemic with exercise intolerance and are at high risk of paradoxical emboli to the brain. About 25...... technical success and few complications. Embolisation prevents cerebral stroke and abscess and pulmonary haemorrhage and further raises the functional level. Screening for pulmonary arteriovenous malformations in patients at risk is recommended....

Surgical attenuation of congenital portosystemic shunts in dogs. Techniques, complications and prognosis

NARCIS (Netherlands)

Kummeling, A.|info:eu-repo/dai/nl/304828793

2009-01-01

The general aim of this thesis was to identify factors associated with outcome after surgical attenuation of congenital portosystemic shunts (CPSS) in dogs and to clarify underlying mechanisms of postoperative recovery in this disease. Two surgical techniques used for CPSS attenuation, ligation and

Usefulness of color and pulsed Doppler's in the evaluation of surgical portosystemic shunts in pediatric patients

International Nuclear Information System (INIS)

Berrocal, T.; Prieto, C.; Cortes, P.; Rodriguez, R.; Pastor, I.

2003-01-01

Portosystemic shunts are performed to relieve symptomatic portal hypertension symptomatic or removal pressure in hepatic vascularisation in patients with Budd-Chiari's syndrome. Most surgical portosystemic shunts can be suitably studied by means of ultrasound scan complemented by color and pulsed Dopplers, proved one understands the hemodynamics of the surgical procedures involved. This article demonstrates the usefulness and limitations of the ultrasound scan Duplex Doppler in the evaluation of portosystemic shunts performed on pediatric patients. Pulsed Doppler provides information regarding the nature and direction of blood flow. Color doppler is capable of directly revealing the shunt and, in most cases, permits the anastomosis to be located. The types of shunts that appear include proximal and distal spleno-renal, portocaval and mesocaval. Types of vascular connections are illustrated,s well as expected post-surgical blood flow direction in affected vessels. The ultrasound scanning technique is discussed, as well as the criteria for determining vascular permeability. Also highlighted are the advantages, limitations and diagnostic difficulties associated with the different forms of Doppler. (Author) 17 refs

Surgical Repair of a Post-traumatic Arteriovenous Fistula Complicated by Stent-Graft Misplacement

International Nuclear Information System (INIS)

Sahin, Sinan; Ciinar, Bayer; Bilgin, Sule N.; Celik, Levent; Eren, Ergin E.

2005-01-01

An arteriovenous fistula (AVF) is an abnormal connection between an artery and a vein which may result from a traumatic injury or occur as a congenital abnormality. It may be asymptomatic or may present with a variety of symptoms. Surgical or endovascular treatment can be preferred. We present a case of unsuccessful percutaneous treatment of a femoral AVF due to misplacement of the stent-grafts, necessitating surgical correction

Developmental intrahepatic shunts of childhood: radiological features and management

International Nuclear Information System (INIS)

Paley, M.R.; Farrant, P.; Kane, P.; Karani, J.B.; Heaton, N.D.; Howard, E.R.

1997-01-01

The purpose of this study was to evaluate the role of radiological techniques in the diagnosis and management of developmental intrahepatic shunts. Hepatic vascular fistulae are recognised sequelae of liver trauma and intrahepatic tumours. However, there are rare developmental malformations which may present in childhood or later life and which may carry life-threatening complications. Retrospective analysis of clinical and radiological data was carried out in 24 patients. Anomalies evaluated were: (a) direct communication between hepatic artery and hepatic veins; (b) congenital hepatoportal arteriovenous malformations; and (c) congenital portocaval anastomosis with persistent flow through the ductus venosus. Although rare, the prompt recognition of these vascular anomalies allows early surgical or radiological intervention and reversal of the haemodynamic complications. (orig.)

Dsa examination and diagnosis of arteriovenous shunts in hepatic cavernous hemangiomas of adults

International Nuclear Information System (INIS)

Ouyang Yong; Ouyang Xuehui; Gu Subin; Zhou Qunhui

2000-01-01

Objective: To correct the misunderstanding that arteriovenous shunts (AVS) are rarely found in adult cavernous hemangiomas of the liver (CHL) and to increase its diagnosis rate by DSA. Methods: DSA examination and DSA images of thirty adults with definitely diagnostic CHL and without evidence of other hepatic diseases and hepatic injury were analyzed retrospectively. X-ray films of 21 cases with AVS taken immediately after transcatheter arterial embolization using lipiodol (L-TAE) were compared with the corresponding DSA images to check up those AVS opacified in DSA by observing sediment and distribution of iodized oil injected. Results: Definite diagnosis of AVS by DSA were obtained in 22 cases of this series (73%). All the AVS were located in the peritumoral parenchyma and appeared as parallel track sign, and early opacification of small draining veins, etc. during arterial phase of DSA. X-ray films taken immediately after L-TAE in 21 of 22 cases with AVS showed that few portal radicles or draining veins were refilled by iodized oil through incompletely occluded shunts in 11 cases, and no any vein was refilled by iodized oil resulted from complete occlusion of the present AVS in 10. No definite AVS was found in the other 8 cases of this series, and in 6 of them improper imaging factors of DSA were used. Conclusion: This study serves to emphasize that AVS is not a diagnosis of hepatic malignancy, but is frequently seen in the commonly benign CHL of adults. Proper imaging factors of DSA and superior images can be helpful to opacify small AVS of CHL. The formation of AVS in CHL may be closely related to the pathological changes of peritumoral parenchyma, however, its mechanism must be further studied

Percutaneous transluminal angioplasty of an occluded surgical splenorenal shunt in a 4-year-old child after liver transplantation

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Yussim, Ethan; Belenky, Alexander; Atar, Eli [Department of Diagnostic Radiology, Rabin Medical Center, Vascular and Interventional Radiology Unit, Petah Tikva (Israel); Shapiro, Rivka [Schneider Children' s Medical Center, Institute of Pediatric Gastroenterology and Nutrition, Petah Tikva (Israel); Mor, Eytan [Rabin Medical Center, Department of Organ Transplantation, Petah Tikva (Israel)

2005-07-01

Percutaneous transluminal angioplasty is increasingly used in children. We present a case of successful balloon angioplasty of an occluded surgical splenorenal shunt in a 4-year-old child who underwent liver transplantation because of biliary atresia. Percutaneous reopening of the shunt is a relatively safe procedure that may spare patients of surgical intervention. (orig.)

Percutaneous transluminal angioplasty of an occluded surgical splenorenal shunt in a 4-year-old child after liver transplantation

International Nuclear Information System (INIS)

Yussim, Ethan; Belenky, Alexander; Atar, Eli; Shapiro, Rivka; Mor, Eytan

2005-01-01

Percutaneous transluminal angioplasty is increasingly used in children. We present a case of successful balloon angioplasty of an occluded surgical splenorenal shunt in a 4-year-old child who underwent liver transplantation because of biliary atresia. Percutaneous reopening of the shunt is a relatively safe procedure that may spare patients of surgical intervention. (orig.)

Arteriovenous malformation of the mandible

International Nuclear Information System (INIS)

Kim, Dong Youn; Lee, Kang Sook; Choi, Karp Shik

1995-01-01

The arteriovenous malformation, an uncommon lesion, is a direct communication between an artery and a vein that bypasses the intervening capillary bed. The authors experienced two cases of arteriovenous malformation in 17-year-old and 18-year-old female patients who had suffered from mandibular pain and gingival bleeding. As a result of careful analysis of clinical and angiographic radiological examinations, we diagnosed them as arteriovenous malformations. The following result were obtained; 1. Main clinical symptoms were dull pain and gingival bleeding on the mandibular body area and redness, pain on palpitation in the lesional sites were also observed. 2. Radiographically, well-defined radiolucent lesions with multiple osteolytic defects were observed. In radionuclide scan, increased uptakes of radioisotope were observed in the lesional sites. 3. Increased venous shunt supplied by the facial, lingual and inferior alveolar arteries was observed in angiography. After embolotherapy was performed, no recurrence was reported during 3 to 6 months follow up.

Perkutan transluminal embolisering af pulmonale arteriovenøse misdannelser

DEFF Research Database (Denmark)

Kjeldsen, A D; Andersen, P E; Oxhøj, H

1998-01-01

A series of nine patients with pulmonary arteriovenous malformations (PAVM) treated with embolotherapy at Odense University Hospital is presented. In all patients the arterial oxygen tension increased after embolisation. PAVM causes right-to-left shunting, which may result in severe hypoxaemia, and...

Developmental intrahepatic shunts of childhood: radiological features and management

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Paley, M.R.; Farrant, P.; Kane, P.; Karani, J.B. [Department of Radiology, King`s College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Heaton, N.D.; Howard, E.R. [Department of Paediatric Hepatobiliary Surgery, King`s College Hospital Denmark Hill, London SE5 9RS (United Kingdom)

1997-12-01

The purpose of this study was to evaluate the role of radiological techniques in the diagnosis and management of developmental intrahepatic shunts. Hepatic vascular fistulae are recognised sequelae of liver trauma and intrahepatic tumours. However, there are rare developmental malformations which may present in childhood or later life and which may carry life-threatening complications. Retrospective analysis of clinical and radiological data was carried out in 24 patients. Anomalies evaluated were: (a) direct communication between hepatic artery and hepatic veins; (b) congenital hepatoportal arteriovenous malformations; and (c) congenital portocaval anastomosis with persistent flow through the ductus venosus. Although rare, the prompt recognition of these vascular anomalies allows early surgical or radiological intervention and reversal of the haemodynamic complications. (orig.) With 7 figs., 4 tabs., 22 refs.

Screening for pulmonary arteriovenous malformations

DEFF Research Database (Denmark)

Oxhøj, H; Kjeldsen, A D; Nielsen, G

2000-01-01

Pulmonary arteriovenous malformations (PAVM) cause right-to-left shunt and imply risk of paradoxical embolism and cerebral abscess. These complications can be prevented by appropriate treatment. Detection of PAVMs is therefore important, so simple and reliable screening methods are needed...... for this purpose. The aim of this investigation was to compare pulse oximetry and contrast echocardiography as screening tools for detection of pulmonary arteriovenous malformations. Eighty-five hereditary haemorrhagic telangiectasia (HHT) patients and first-degree relatives identified in a comprehensive study...... echocardiography with intravenous injection of echo contrast was performed in all subjects. Outcome measures were oxygen saturation change >2% units on changing body position and echo contrast observed in the left-sided heart chambers. Positive contrast echocardiography indicating the presence of PAVM was found...

Complex arteriovenous malformation - a case report

International Nuclear Information System (INIS)

Sirakov, S.; Penkov, M.; Marinov, M.; Kamenov, B.

2014-01-01

AVMs are composed of a network of channels interposed between feeding arteries and draining veins, without any direct shunt. Two different anatomic types of nidus may be more or less differentiated: The most frequent clinical presentations of brain AVMs are hemorrhage, seizure, chronic headache, and focal deficits not related to hemorrhage. We show a case of 27 years old female came to the hospital in heavy condition with subarachnoid hemorrhage Fisher 4. She had a history of 4 surgical operation of brain AVM in the last 10 years, without significant reduction of the malformation. After discussion of multidisciplinary team, of neuroradiologist and neurosurgeon was decided to be perform endovascular embolization, because of the better outcome for the patient. We performed endovascular treatment of the AVM with achieving subtotal embolization of malformation (90%). The patient recovery completely after 22 days and went home. For the next 18 months follow up there is no data of accidents for the patient. Key words: Arteriovenous Malformation. Subarachnoid hemorrhage. Endovascular treatment. Embolization

Oral Surgical Procedures Performed Safely in Patients With Head and Neck Arteriovenous Malformations: A Retrospective Case Series of 12 Patients.

Science.gov (United States)

Karim, Abdul Basit; Lindsey, Sean; Bovino, Brian; Berenstein, Alejandro

2016-02-01

This case series describes patients with head and neck arteriovenous malformations who underwent oral and maxillofacial surgical procedures combined with interventional radiology techniques to minimize blood loss. Twelve patients underwent femoral cerebral angiography to visualize the extent of vascular malformation. Before the surgical procedures, surgical sites were devascularized by direct injection of hemostatic or embolic agents. Direct puncture sclerotherapy at the base of surgical sites was performed using Surgiflo or n-butylcyanoacrylate glue. Surgical procedures were carried out in routine fashion. A hemostatic packing of FloSeal, Gelfoam, and Avitene was adapted to the surgical sites. Direct puncture sclerotherapy with Surgiflo or n-butylcyanoacrylate glue resulted in minimal blood loss intraoperatively. Local application of the FloSeal, Gelfoam, and Avitene packing sustained hemostasis and produced excellent healing postoperatively. Patients with arteriovenous malformations can safely undergo routine oral and maxillofacial surgical procedures with minimal blood loss when appropriate endovascular techniques and local hemostatic measures are used by the interventional radiologist and oral and maxillofacial surgeon. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Usefulness of color and pulsed Doppler's in the evaluation of surgical portosystemic shunts in pediatric patients; Utilidad del Doppler color y pulsado en la valoracion de los shunts portosistemicos quirurgicos en la edad pediatrica

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Berrocal, T.; Prieto, C.; Cortes, P.; Rodriguez, R.; Pastor, I. [Hospital Universitario La Paz. Madrid (Spain)

2003-07-01

Portosystemic shunts are performed to relieve symptomatic portal hypertension symptomatic or removal pressure in hepatic vascularisation in patients with Budd-Chiari's syndrome. Most surgical portosystemic shunts can be suitably studied by means of ultrasound scan complemented by color and pulsed Dopplers, proved one understands the hemodynamics of the surgical procedures involved. This article demonstrates the usefulness and limitations of the ultrasound scan Duplex Doppler in the evaluation of portosystemic shunts performed on pediatric patients. Pulsed Doppler provides information regarding the nature and direction of blood flow. Color doppler is capable of directly revealing the shunt and, in most cases, permits the anastomosis to be located. The types of shunts that appear include proximal and distal spleno-renal, portocaval and mesocaval. Types of vascular connections are illustrated,s well as expected post-surgical blood flow direction in affected vessels. The ultrasound scanning technique is discussed, as well as the criteria for determining vascular permeability. Also highlighted are the advantages, limitations and diagnostic difficulties associated with the different forms of Doppler. (Author) 17 refs.

Retinal complications after aqueous shunt surgical procedures for glaucoma.

Science.gov (United States)

Law, S K; Kalenak, J W; Connor, T B; Pulido, J S; Han, D P; Mieler, W F

1996-12-01

To assess retinal complications and to identify risk factors for retinal complications following aqueous shunt procedures. Records of 38 consecutive aqueous shunt procedures that were performed on 36 patients at the Eye Institute of the Medical College of Wisconsin, Milwaukee, from June 1993 to March 1995 (minimum follow-up, 6 months) were reviewed. The mean +/- SD follow-up was 11.4 +/- 5.2 months (median, 10.5 months). Twelve patients (32%) had the following retinal complications: 4 serous choroidal effusions (10%) that required drainage, 3 suprachoroidal hemorrhages (8%), 2 vitreous hemorrhages (5%), 1 rhegmatogenous retinal detachment (3%), 1 endophthalmitis (3%), and 1 scleral buckling extrusion (3%). Surgical procedures for retinal complications were required in 8 (67%) of these 12 patients. Visual acuity decreased 2 lines or more in 9 (75%) of these 12 patients. The median onset of a postoperative retinal complication was 12.5 days, with 10 patients (83%) experiencing complications within 35 days. Serous choroidal effusions developed in 10 other patients (26%), and these effusions resolved spontaneously. Visual acuity decreased 2 lines or more in 2 (20%) of these additional 10 patients. Patients who experienced serious retinal complications were significantly older, had a higher rate of hypertension, and postoperative ocular hypotony. Serious retinal complications were distributed evenly among patients with Krupin valves with discs and Molteno and Baerveldt devices. Experience with the Ahmed glaucoma valve implant was limited. Aqueous shunt procedures may be associated with significant retinal complications and subsequent visual loss.

Arteriovenous shunt graft ulceration with sinus and graft epithelialization

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Pooja Singhal

2015-03-01

Full Text Available Arteriovenous fistula and grafts are used as access sites for patients with chronic kidney disease and are prone for complications. Stent grafts are used to treat access site complications. We report a rare and unusual finding of epithelialization of the sinus tract and the lumen of a polytetrafluoroethylene graft, following ulceration of the overlying skin.

CT in normal pressure hydrocephalus. Correlation between CT and clinical response to shunting

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Fujita, K.; Nogaki, H.; Noda, M.; Kusunoki, T.; Tamaki, N. (Kobe Univ. (Japan). School of Medicine)

1981-02-01

CT scans were obtained on 33 patients (age 73y. to 31y.) with the diagnosis of normal pressure hydrocephalus. In each case, the diagnosis was made on the basis of the symptoms, CT and cisternographic findings. Underlying diseases of normal pressure hydrocephalus are ruptured aneurysms (21 cases), arteriovenous malformations (2 cases), head trauma (1 case), cerebrovascular accidents (1 case) and idiopathie (8 cases). Sixteen of 33 patients showed marked improvement, five, moderate or minimal improvement, and twelve, no change. The results were compared with CT findings and clinical response to shunting. CT findings were classified into five types, bases on the degree of periventricular hypodensity (P.V.H.), the extent of brain damage by underlying diseases, and the degree of cortical atrophy. In 17 cases of type (I), CT shows the presence of P.V.H. with or without minimal frontal lobe damage and no cortical atrophy. The good surgical improvements were achieved in all cases of type (I) by shunting. In 4 cases of type (II), CT shows the presence of P.V.H. and severe brain damage without cortical atrophy. The fair clinical improvements were achieved in 2 cases (50%) by shunting. In one case of type (III), CT shows the absence of P.V.H. without brain damage nor cortical atrophy. No clinical improvement was obtained by shunting in this type. In 9 cases of type (IV) with mild cortical atrophy, the fair clinical improvement was achieved in two cases (22%) and no improvement in 7 cases. In 2 cases of type (V) with moderate or marked cortical atrophy, no clinical improvement was obtained by shunting. In conclusion, it appeared from the present study that there was a good correlation between the result of shunting and the type of CT, and clinical response to shunting operation might be predicted by classification of CT findings.

[INTERVENTIONAL AND SURGICAL TREATMENT OF THE ANGINA PECTORIS RECURRENCE AFTER CORONARY SHUNTING OPERATION].

Science.gov (United States)

Fanta, S M

2015-12-01

There were examined 134 patients, in whom in the clinic in 2005-2014 yrs a coronary shunting operation was performed. In patients with the angina pectoris recurrence a reoperation is indicated. The data of repeated coronaroventriculography and shuntography were analyzed. Efficacy of the surgical and interventional methods application in the patients was proved.

Surgical excision of a cerebral arteriovenous malformation in a dog

International Nuclear Information System (INIS)

Thomas, W.B.; Schueler, R.O.; Kornegay, J.N.

1995-01-01

A 7-year-old dog was presented with seizures and epistaxis. Computed tomography showed a contrast-enhancing lesion in the cerebrum. An arteriovenous malformation was identified at surgery and resected. A discussion of intracranial arteriovenous malformation is presented

Surgical experience with arteriovenous malformations of the brain

International Nuclear Information System (INIS)

Stein, B.M.

1984-01-01

Personal experience with the treatment of 200 arteriovenous malformations of the brain seen during the past decade is presented. One hundred and twenty of these patients underwent surgery, with a mortality of 1,7%. The morbidity rate of 10% includes cases of hemianopia after occipital malformations had been removed. Significant morbidity, including aphasia, hemiparesis and hemisensory loss, occurred in under 10% of cases. Computerized tomography plays an important role in determining the relationships of the arteriovenous malformations to associated structures such as the ventricular system

Management of patients with brain arteriovenous malformations

International Nuclear Information System (INIS)

Soederman, Michael; Andersson, Tommy; Karlsson, Bengt; Wallace, M. Christopher; Edner, Goeran

2003-01-01

Arteriovenous malformations (AVMs) of the brain, which are probably genetically determined, are errors in the development of the vasculature that, together with the effects of blood flow, may lead to a focal arteriovenous shunt. Clinically, the adult patient may present with acute or chronic neurological symptoms--fixed or unstable--such as deficits, seizures or headache. Sometimes the lesion is an incidental finding. In about half of the patients, the revealing event is an intracranial haemorrhage. The prevalence of AVM in the western world is probably 10 ml could benefit from targeted partial embolisation followed by radiosurgery or surgery, depending on the angioarchitecture; and (IV) AVMs >20 ml nidus volume usually have a high treatment risk with any treatment modality and are not obvious targets for treatment at all

Surgical Treatment for a Complex Congenital Arteriovenous Malformation of the Lower Limb

OpenAIRE

Ozcan, Ali Vefa; Boysan, Emre; Isikli, Osman Yasar; Goksin, Ibrahim

2013-01-01

Arteriovenous fistula is defined as an abnormal communication between the arterial and venous systems. The complexity of congenital arteriovenous malformations makes treatment challenging. We present the case of a 23-year-old woman who had a complex congenital arteriovenous malformation in her left leg and a history of 2 unsuccessful coil-embolization procedures. We ligated all the feeding arteries of the arteriovenous malformation in the region of the superficial femoral artery, and the surg...

Surgical approach for systemic-pulmonary shunt in neonates with functionally univentricular heart: comparison between sternotomy and thoracotomy.

Science.gov (United States)

Sasaki, Takashi; Takeda, Yuko; Ohnakatomi, Yasuko; Asou, Toshihide

2016-09-01

The preferred surgical approach for systemic-pulmonary shunts has changed from thoracotomy to sternotomy in our institution, to concomitantly manage the ductus arteriosus during surgery. The purpose of this study was to compare the outcomes of systemic-pulmonary shunts for neonates with functionally univentricular hearts based on surgical approach. Fifty-two neonates with functionally univentricular hearts underwent systemic-pulmonary shunt via sternotomy (n = 28) or thoracotomy (n = 24). Patient characteristics, achievement rates of right heart bypass, and survival rates were compared for the different approaches. Prenatal diagnosis was made more common in the sternotomy group (p = 0.006). The shunt was placed more centrally in the sternotomy group. The ductus arteriosus was ligated or banded in most patients in the sternotomy group (26/28) and in a few patients in the thoracotomy group (6/24). Frequency of ductal management in the early postoperative phase was not different between the groups (21 vs 25 %), but three new incisions had to be made in the thoracotomy group. No differences were seen in the achievement rates of bidirectional cavopulmonary shunts (86 vs 87 % at 10 months of age) and total cavopulmonary connection (81 vs 81 % at 2 years of age), or in the survival rates (92 vs 96 % at 8 years). There were no differences in short- and long-term outcomes between the groups. The sternotomy approach might be preferable in the current era of prenatal diagnosis, to allow simultaneous duct management during systemic-pulmonary shunt surgery, particularly in patients with large ducts associated with functionally univentricular hearts.

Systemic arteriovenous malformations as a cause of cardiac failure: Treatment with embolization

International Nuclear Information System (INIS)

Smith, E.J.; Hemingway, A.P.; Allison, D.J.

1987-01-01

Massive cogenital systemic arteriovenous malformations (AVMs) present considerable management problems for clinicians. Their size, position, and vascularity make successful surgical reaction impossible. Attempts at resection produce only temporary relief of symptoms and cause further disfigurement. Large AVMs give rise to pain, swelling, and distal ischaemia, can erode bone, and give rise to life-threatening hemorrhage, and a massive left or right shunt causes high-output cardiac failure and death. Ten patients (age range, 5-50 years; mean 26 years) have massive AVMs giving rise to high-output cardiac failure (26-28 liters). These patients (seven male, three female), have undergone a total of 43 embolization procedures. The advent of nonionic contrast media, digital subtraction angiography, steel coils, and balloons allows us to successfully treat these patients who until recently were condemned to die in high-output cardiac failure

Combined endovascular and surgical treatment in vertebral arteriovenous fistula

International Nuclear Information System (INIS)

Nakstad, P.H.; Haakonsen, M.; Magnaes, B.; Hetland, S.

1997-01-01

A 7-year-old girl with a right-sided congenital arteriovenous fistula in the neck was admitted with signs of cardial incompensation. Her fistula was fed from the right vertebral artery in antegrade as well as retrograde directions. A steal from the intracranial arteries was established. In addition, smaller feeding arteries from the neck were found. She was operated on with ligation of the right vertebral artery proximal to the fistula but the attempted ligation of the artery cranially to the fistula was unsuccessful. She was therefore embolized by the formation of a plug of platinum fiber coils in the upper right vertebral artery. Catheterization was performed from the left vertebral artery via the basilar artery. Persisting minor feeders to the fistula from cervical arteries were embolized in a second session. Finally, surgical extirpation of the fistula was performed together with the operative ligation of a crossover feeding artery from the left vertebral artery. Her heart size, heart rate and blood pressure were successively normalized. (orig.)

A Case of De Novo Anterior Condylar Dural Arteriovenous Fistula Long after Curative Transvenous Embolization of Contralateral Anterior Condylar Arteriovenous Fistula

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Shinya Hagiwara

2016-01-01

Full Text Available We report on a 55-year-old man who developed a de novo DAVF in left ACC 5 years after curative transvenous embolization for DAVF in right ACC. Angiography revealed that the de novo lesion demonstrated more aggressive arteriovenous shunt flow than the initial lesion. Successful transvenous embolization was performed for also the second lesion. The authors describe the possible pathophysiological mechanisms and management strategies for this rare occurrence.

Imaging findings of arteriovenous malformations involving lung and liver in hereditary hemorrhagic telangiectasia(Osler-weber-rendu disease): two cases report

Energy Technology Data Exchange (ETDEWEB)

Yi, Jeong Geun; Lee, Joo Hyuk; Seong, Su Ok [Cheongju St. Mary' s Hospital, Cheongju (Korea, Republic of)

1999-09-01

Hereditary hemorrhagic telangiectasia (HHT) or Osler-Weber-Rendu disease is an autosomal dominant disorder characterized by repeated episodes of bleeding. Multiple telangiectases consisting of thin-walled, dilated vascular channels with arteriovenous communication may involve, for example, mucocutaneous tissue, the gastrointestinal tract, and the liver, lung, and brain. We report the imaging findings of two cases of HHT involving arteriovenous malformation of both the lungs and liver, a rare condition. Chest radiography revealed a round mass, while helical CT showed a feeding artery and draining vein with arteriovenous malformation in the lung. Color Doppler sonography revealed an enlarged and tortuous hepatic artery with high systolic velocity. CT demonstrated an enlarged hepatic artery, arteriovenous shunt, and early draining hepatic vein in the liver. Celiac angiography showed arteriovenous malformation.

Imaging findings of arteriovenous malformations involving lung and liver in hereditary hemorrhagic telangiectasia(Osler-weber-rendu disease): two cases report

International Nuclear Information System (INIS)

Yi, Jeong Geun; Lee, Joo Hyuk; Seong, Su Ok

1999-01-01

Hereditary hemorrhagic telangiectasia (HHT) or Osler-Weber-Rendu disease is an autosomal dominant disorder characterized by repeated episodes of bleeding. Multiple telangiectases consisting of thin-walled, dilated vascular channels with arteriovenous communication may involve, for example, mucocutaneous tissue, the gastrointestinal tract, and the liver, lung, and brain. We report the imaging findings of two cases of HHT involving arteriovenous malformation of both the lungs and liver, a rare condition. Chest radiography revealed a round mass, while helical CT showed a feeding artery and draining vein with arteriovenous malformation in the lung. Color Doppler sonography revealed an enlarged and tortuous hepatic artery with high systolic velocity. CT demonstrated an enlarged hepatic artery, arteriovenous shunt, and early draining hepatic vein in the liver. Celiac angiography showed arteriovenous malformation

Coil occlusion of residual shunts after surgical closure of patent ductus arteriosus.

Science.gov (United States)

Fujii, Yoko; Keene, Bruce W; Mathews, Kyle G; Atkins, Clarke E; Defrancesco, Teresa C; Hardie, Elizabeth M; Wakao, Yoshito

2006-12-01

OBJECTIVE; To describe use of coil embolization to occlude residual flow through a patent ductus arteriosus (PDA) after incomplete surgical ligation. Clinical study. Dogs (n=4) with continuous murmur after surgical ligation of PDA. After PDA ligation, residual ductal flow through the PDA was visible on color-flow Doppler examination and left ventricular end-diastolic diameter remained increased. Coil embolization by an arterial approach was performed to achieve complete occlusion of the PDA. Embolization coils were delivered without complications and hemodynamically successful occlusion was achieved. Doppler-visible flow resolved in 2 dogs within 3 months after embolization. Left ventricular end-diastolic diameter indexed to body weight decreased in all dogs. Transcatheter coil embolization appears to be a safe and minimally invasive procedure for complete occlusion of residual PDA flow after incomplete surgical ligation. Transcatheter coil embolization should be considered for correction of hemodynamically significant residual shunts in dogs that have incomplete PDA occlusion after open surgical ligation.

Surgical outcome of severe pulmonary arterial hypertension secondary to left-to-right shunt lesions

Directory of Open Access Journals (Sweden)

Cha Gon Lee

2010-02-01

Full Text Available Purpose : Despite recent advances in pulmonary hypertension management and surgery, appropriate guidelines remain to be developed for operability in congenital heart disease with pulmonary artery hypertension (PAH. Our aim was to evaluate clinical outcomes of patients with severe PAH who underwent surgical closure of left-to-right shunt lesions (LRSL on the basis of pulmonary reactivity. Methods : We retrospectively reviewed 21 patients who underwent surgical closure of LRSL with severe PAH (?#248; Wood unit from January 1995 to April 2009. The median age at operation was 26 years. Atrial septal defect, ventricular septal defect (VSD, VSD and patent ductus arteriosus (PDA, and PDA was present in 11, 4, 4, and 2 patients, respectively. Results : Operability was based on vasoreactivity of PAH. Of the 21 patients, 5 showed response to pulmonary vasodilator therapy and 8 showed vasoreactivity after balloon occlusion of defects. The remaining 8 patients were considered operable because of significant left-to-right shunt (Qp/Qs ?#241;.5. Five patients underwent total closure of defects and 16 were left with small residual shunts. The median follow-up duration was 32 months. There was no significant postoperative mortality or morbidity. Systolic pulmonary artery pressure (PAP decreased in all but 2 patients. All patients except 1 showed improvement of New York Heart Association functional class. Conclusion : Closure of LRSL in patients with severe PAH on the basis of pulmonary vasoreactivity seems reasonable. PAP and clinical symptoms improved in most patients. Further research is needed for the evaluation of long-term results.

Ventriculoperitoneal shunt blockage by hydatid cyst

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Abrar A Wani

2013-01-01

Full Text Available Ventriculoperitoneal (VP shunt is one of the commonest procedures done in neurosurgical practice throughout the world. One of the commonest problems after putting the VP shunt is the shunt obstruction, which can be due to varied causes. Shunt obstruction secondary to the parasitic infections is rarely seen. We are presenting a 15-year-old child, a case of operated cerebral hydatid cyst with hydrocephalus. She presented with shunt malfunction after 1 year of surgical excision of the hydatid cyst. Revision of the VP shunt was done and peroperatively, it was found that the shunt tubing was obstructed due to small hydatid cysts. This is the first reported case of VP shunt obstruction by hydatid cyst.

Congenital extrahepatic portosystemic shunt associated with heterotaxy and polysplenia

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Newman, Beverley [Lucile Packard Children' s Hospital, Department of Radiology, Stanford University School of Medicine, Stanford, CA (United States); Feinstein, Jeffrey A. [Stanford University School of Medicine, Division of Pediatric Cardiology, Department of Pediatrics, Lucile Packard Children' s Hospital, Stanford (United States); Cohen, Ronald A.; Patel, Hitendra [Children' s Hospital and Research Center, Department of Diagnostic Radiology, Oakland, CA (United States); Feingold, Brian; Kreutzer, Jacqueline [Children' s Hospital of Pittsburgh, Department of Pediatrics, Division of Pediatric Cardiology, Pittsburgh, PA (United States); Chan, Fandics P. [Stanford University School of Medicine, Cardiovascular Imaging Section, Department of Radiology, Lucile Packard Children' s Hospital, Stanford, CA (United States)

2010-07-15

Heterotaxy with polysplenia is associated with many cardiovascular anomalies including the occasional occurrence of congenital extrahepatic portosystemic shunts (CEPS). Missing this anomaly can lead to inappropriate and ineffective therapy. To emphasize the importance and associated anatomy of CEPS in conjunction with heterotaxy with polysplenia. Review of three young children who presented with cyanosis and pulmonary hypertension without a cardiac etiology. They were known (1) or discovered (2) to have heterotaxy with polysplenia. There was absence of the intrahepatic inferior vena cava (IVC) with azygos or hemiazygos continuation in all three cases. In spite of normal liver function, they were discovered to have large portosystemic shunts, splenorenal in location, along with diffuse peripheral pulmonary arterial dilatation suggestive of CEPS (Abernethy malformation) with hepatopulmonary or, more accurately, portopulmonary syndrome. All CEPS were ipsilateral to the spleens. Patency of the portal veins in these cases allowed for percutaneous shunt closure with resolution of cyanosis. CEPS is associated with heterotaxy with polysplenia and can be symptomatic because of pulmonary arteriovenous (AV) shunting. Portal and hepatic vein patency are critical for determining feasibility of CEPS closure. (orig.)

Double Coaxial Microcatheter Technique for Glue Embolization of Renal Arteriovenous Malformations

International Nuclear Information System (INIS)

Uchikawa, Yoko; Mori, Kensaku; Shiigai, Masanari; Konishi, Takahiro; Hoshiai, Sodai; Ishigro, Toshitaka; Hiyama, Takashi; Nakai, Yasunobu; Minami, Manabu

2015-01-01

PurposeTo demonstrate the technical benefit of the double coaxial microcatheter technique for embolization of renal arteriovenous malformations (AVMs) with n-butyl cyanoacrylate and iodized oil (glue).Materials and MethodsSix consecutive patients (1 man and 5 women; mean age 61 years; range 44–77 years) with renal AVMs were included. Five patients had hematuria, and one had a risk of heart failure due to a large intrarenal arteriovenous shunt. All patients underwent transarterial embolization using glue and the double coaxial microcatheter technique with outer 2.6F and inner 1.9F microcatheters. After glue injection, the inner microcatheter was retracted, while the outer microcatheter was retained. We assessed the complications and clinical outcomes of this technique.ResultsTechnical success was achieved in all patients. In 9 sessions, 34 feeding arteries were embolized with glue using the double coaxial microcatheter technique, 1 was embolized with glue using a single microcatheter, and 2 were embolized with coils. The double coaxial microcatheter technique was useful for selecting small tortuous feeding arteries, preventing glue reflux to the proximal arteries, and approaching multiple feeding arteries without complete retraction of the microcatheters. As a minor complication, glue migrated into the venous system in four patients without any sequelae. In all patients, favorable clinical outcomes, including hematuria cessation in five patients and improvement of the large intrarenal arteriovenous shunt in one patient, were obtained without deterioration of renal function.ConclusionGlue embolization with the double coaxial microcatheter technique was useful for treating renal AVMs with multiple tortuous feeding arteries

Double Coaxial Microcatheter Technique for Glue Embolization of Renal Arteriovenous Malformations

Energy Technology Data Exchange (ETDEWEB)

Uchikawa, Yoko, E-mail: jauchikawa@gmail.com [University of Tsukuba Hospital, Department of Radiology (Japan); Mori, Kensaku, E-mail: moriken@md.tsukuba.ac.jp [University of Tsukuba, Department of Radiology, Faculty of Medicine (Japan); Shiigai, Masanari, E-mail: m-41gai@yahoo.co.jp [Tsukuba Medical Center Hospital, Department of Radiology (Japan); Konishi, Takahiro, E-mail: soratobukangaruu@gmail.com [University of Tsukuba Hospital, Department of Radiology (Japan); Hoshiai, Sodai, E-mail: hoshiai@sb4.so-net.ne.jp [Ibaraki Prefectural Central Hospital, Department of Radiology (Japan); Ishigro, Toshitaka, E-mail: suzutokei@gmail.com; Hiyama, Takashi, E-mail: med-tak@hotmail.com [University of Tsukuba Hospital, Department of Radiology (Japan); Nakai, Yasunobu, E-mail: nakaiya@tmch.or.jp [Tsukuba Medical Center Hospital, Department of Neurosurgery (Japan); Minami, Manabu, E-mail: mminami@md.tsukuba.ac.jp [University of Tsukuba, Department of Radiology, Faculty of Medicine (Japan)

2015-10-15

PurposeTo demonstrate the technical benefit of the double coaxial microcatheter technique for embolization of renal arteriovenous malformations (AVMs) with n-butyl cyanoacrylate and iodized oil (glue).Materials and MethodsSix consecutive patients (1 man and 5 women; mean age 61 years; range 44–77 years) with renal AVMs were included. Five patients had hematuria, and one had a risk of heart failure due to a large intrarenal arteriovenous shunt. All patients underwent transarterial embolization using glue and the double coaxial microcatheter technique with outer 2.6F and inner 1.9F microcatheters. After glue injection, the inner microcatheter was retracted, while the outer microcatheter was retained. We assessed the complications and clinical outcomes of this technique.ResultsTechnical success was achieved in all patients. In 9 sessions, 34 feeding arteries were embolized with glue using the double coaxial microcatheter technique, 1 was embolized with glue using a single microcatheter, and 2 were embolized with coils. The double coaxial microcatheter technique was useful for selecting small tortuous feeding arteries, preventing glue reflux to the proximal arteries, and approaching multiple feeding arteries without complete retraction of the microcatheters. As a minor complication, glue migrated into the venous system in four patients without any sequelae. In all patients, favorable clinical outcomes, including hematuria cessation in five patients and improvement of the large intrarenal arteriovenous shunt in one patient, were obtained without deterioration of renal function.ConclusionGlue embolization with the double coaxial microcatheter technique was useful for treating renal AVMs with multiple tortuous feeding arteries.

Surgical planning for microsurgical excision of cerebral arterio-venous malformations using virtual reality technology.

Science.gov (United States)

Ng, Ivan; Hwang, Peter Y K; Kumar, Dinesh; Lee, Cheng Kiang; Kockro, Ralf A; Sitoh, Y Y

2009-05-01

To evaluate the feasibility of surgical planning using a virtual reality platform workstation in the treatment of cerebral arterio-venous malformations (AVMs) Patient-specific data of multiple imaging modalities were co-registered, fused and displayed as a 3D stereoscopic object on the Dextroscope, a virtual reality surgical planning platform. This system allows for manipulation of 3D data and for the user to evaluate and appreciate the angio-architecture of the nidus with regards to position and spatial relationships of critical feeders and draining veins. We evaluated the ability of the Dextroscope to influence surgical planning by providing a better understanding of the angio-architecture as well as its impact on the surgeon's pre- and intra-operative confidence and ability to tackle these lesions. Twenty four patients were studied. The mean age was 29.65 years. Following pre-surgical planning on the Dextroscope, 23 patients underwent microsurgical resection after pre-surgical virtual reality planning, during which all had documented complete resection of the AVM. Planning on the virtual reality platform allowed for identification of critical feeders and draining vessels in all patients. The appreciation of the complex patient specific angio-architecture to establish a surgical plan was found to be invaluable in the conduct of the procedure and was found to enhance the surgeon's confidence significantly. Surgical planning of resection of an AVM with a virtual reality system allowed detailed and comprehensive analysis of 3D multi-modality imaging data and, in our experience, proved very helpful in establishing a good surgical strategy, enhancing intra-operative spatial orientation and increasing surgeon's confidence.

Assessment of Arteriovenous Shunt Pathway Function and Hypervolemia for Hemodialysis Patients by Using Integrated Rapid Screening System

Directory of Open Access Journals (Sweden)

Wei-Ling Chen

2017-06-01

Full Text Available Currently, the hemodialysis patients received body weight measurement by themselves, vital sign checking by nursing staffs before dialysis. Whenever, the arteriovenous routes with problems doubted, the patients needed to be referred to surgeon for vascular echography checking and then to be corrected. How to integrate these three tasks in one time is a very important issue. The project proposes to combine our previous study of audio-phono angiographic technology in detecting vascular stenosis with rapid screening system to evaluate dialysis patients’ arteriovenous routes function and their status of excess body fluids: inspecting and integrating the blood pressure, body weight, and fistula function work into a rapid screening system, and using the quantization of fistula phono angiography pitch to achieve assessing arteriovenous routes. Future hoping is developed a complete integrated intelligence system by combining the arteriovenous fistula signal processing with feature extraction with wireless sensor network technology.

Endovascular and surgical treatment of spinal dural arteriovenous fistulas

International Nuclear Information System (INIS)

Andres, Robert H.; University of Berne; Stanford University Medical Center, Department of Neurosurgery, Stanford, CA; University of Berne; Barth, Alain; Medical University of Graz, Department of Neurosurgery, Graz; University of Berne; Guzman, Raphael; Stanford University Medical Center, Department of Neurosurgery, Stanford, CA; University of Berne; Remonda, Luca; El-Koussy, Marwan; Schroth, Gerhard; University of Berne; Seiler, Rolf W.; Widmer, Hans R.; University of Berne

2008-01-01

The aim of this retrospective study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas (SDAVFs) that were treated with surgery, catheter embolization, or surgery after incomplete embolization. The study included 21 consecutive patients with SDAVFs of the thoracic, lumbar, or sacral spine who were treated in our institution from 1994 to 2007. Thirteen patients were treated with catheter embolization alone. Four patients underwent hemilaminectomy and intradural interruption of the fistula. Four patients were treated by endovascular techniques followed by surgery. The clinical outcome was assessed using the modified Aminoff-Logue scale (ALS) for myelopathy and the modified Rankin scale (MRS) for general quality of life. Patient age ranged from 44 to 77 years (mean 64.7 years). Surgical as well as endovascular treatment resulted in a significant improvement in ALS (-62.5% and -31.4%, respectively, p<0.05) and a tendency toward improved MRS (-50% and -32%, respectively) scores. Patients that underwent surgery after endovascular treatment due to incomplete occlusion of the fistula showed only a tendency for improvement in the ALS score (-16.7%), whereas the MRS score was not affected. We conclude that both endovascular and surgical treatment of SDAVFs resulted in a good and lasting clinical outcome in the majority of cases. In specific situations, when a secondary neurosurgical approach was required after endovascular treatment to achieve complete occlusion of the SDAVF, the clinical outcome was rather poor. The best first line treatment modality for each individual patient should be determined by an interdisciplinary team. (orig.)

Appraising the plasticity of the circle of Willis: a model of hemodynamic modulation in cerebral arteriovenous malformations.

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Chuang, Yu-Ming; Guo, Wanyuo; Lin, Ching-Po

2010-01-01

Cerebral arteriovenous malformations (AVMs) harbor a network of abnormal vasculatures, namely the nidus between arterial and venous components. The pressure gradient between these two components results in abnormal high-velocity arteriovenous shunts flowing through the nidus and alternate intracranial hemodynamics. This study hypothesizes that the flow patterns of the circle of Willis (CoW) are modulated by the alternation of intracranial hemodynamics occurring in cerebral AVMs. The flow patterns of the CoW before and after AVMs had been corrected and the arteriovenous shunts closed by radiosurgery were assessed to validate the hypothesis. Fifty patients (32 men and 18 women; mean age 35.8 +/- 4.2, range 23-52 years) with cerebral AVMs previously treated by radiosurgery were retrospectively investigated. This investigation used magnetic resonance angiography, performed prior to and after AVM surgery, to assess the CoW flow patterns. The CoW flow patterns in nearly half of the subjects (20/50, 40%) altered after the AVMs had been corrected. The alterations included: (1) decreased size or ceased flow patterns in the CoW vascular segment: ipsilateral A1 (n = 1) of the anterior cerebral artery (ACA), ipsilateral posterior communicating artery (PCoA) segment (n = 7), contralateral PCoA collateral (n = 4), bilateral PCoA (n = 2); (2) increased size or opening of the previous 'hypoplastic' segment of CoW: ipsilateral A1 of ACA (n = 1), contralateral PCoA (n = 2), bilateral PCoA (n = 1), and (3) biphasic alteration of the CoW: ceased ipsilateral PCoA segment and opening ipsilateral A1 of the ACA (n = 1), ceased ipsilateral PCoA and opening contralateral P1 of the posterior cerebral artery (n = 1). The plasticity of the flow patterns in the CoW are modulated by intracranial hemodynamics as shown by the AVM model. The calibers of CoW arterial segments are not a static feature. Willisian collateralization with recruitment of the CoW segment may cease, or hypoplastic segments

Transluminal angioplasty of a stenotic surgical splenorenal shunt

International Nuclear Information System (INIS)

Beers, B. van; Roche, A.; Cauquil, P.

1988-01-01

A stenosis of a side-to-side splenorenal shunt was treated by percutaneous angioplasty two years after the performance of the shunt. After dilatation, there was a fall of the splenorenal pressure gradient from 28 to 17 cm H 2 O and good transanastomotic flow was re-estabilshed. As in other arterial and venous territories, angioplasty may be an interesting alternative to surgery. (orig.)

Interventional treatment of pulmonary arteriovenous malformations

DEFF Research Database (Denmark)

Andersen, Poul Erik; Kjeldsen, Anette Drøhse

2010-01-01

Pulmonary arteriovenous malformations (PAVM) are congenital vascular communications in the lungs. They act as right to left shunts so that the blood running through these malformations is not oxygenated or filtered. These patients are typically hypoxaemic with exercise intolerance and are at high...... risk of paradoxical emboli to the brain and other organs. These malformations are most commonly seen in hereditary haemorrhagic telangiectasia (HHT) (Mb. Osler-Weber-Rendu syndrome). Nowadays, the generally accepted treatment strategy of first choice is embolization of the afferent arteries...... the functional level. Embolization is a well-established method of treating PAVM, with a significant effect on oxygenation of the blood. Screening for PAVM in patients at risk is recommended, especially in patients with HHT....

Genetic and Functional Analysis of Congenital Portosystemic Shunts in Dogs

NARCIS (Netherlands)

van den Bossche, L.

2017-01-01

The general aim of this thesis was to gain further insight into the pathogenesis of congenital portosystemic shunts (CPSS), elucidate mechanisms involved in the pathophysiology of CPSS, and explore predictors of recovery after surgical ligation of the shunt. For intrahepatic portosystemic shunts

Failed Ventriculoperitoneal Shunt: Is Retrograde Ventriculosinus Shunt a Reliable Option?

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Oliveira, Matheus Fernandes de; Teixeira, Manoel Jacobsen; Reis, Rodolfo Casimiro; Petitto, Carlo Emanuel; Gomes Pinto, Fernando Campos

2016-08-01

Currently, the treatment of hydrocephalus is mainly carried out through a ventriculoperitoneal shunt (VPS) insertion. However, in some cases, there may be surgical revisions and requirement of an alternative distal site for shunting. There are several described distal sites, and secondary options after VPS include ventriculopleural and ventriculoatrial shunt, which have technical difficulties and harmful complications. In this preliminary report we describe our initial experience with retrograde ventriculosinus shunt (RVSS) after failed VPS. In 3 consecutive cases we applied RVSS to treat hydrocephalus in shunt-dependent patients who had previously undergone VPS revision and in which peritoneal space was full of adhesions and fibrosis. RVSS was performed as described by Shafei et al., with some modifications to each case. All 3 patients kept the same clinical profile after RVSS, with no perioperative or postoperative complications. However, revision surgery was performed in the first operative day in 1 out of 3 patients, in which the catheter was not positioned in the superior sagittal sinus. We propose that in cases where VPS is not feasible, RVSS may be a safe and applicable second option. Nevertheless, the long-term follow-up of patients and further learning curve must bring stronger evidence. Copyright © 2016 Elsevier Inc. All rights reserved.

Cerebral Abscess Associated With Odontogenic Bacteremias, Hypoxemia, and Iron Loading in Immunocompetent Patients With Right-to-Left Shunting Through Pulmonary Arteriovenous Malformations

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Boother, Emily J.; Brownlow, Sheila; Tighe, Hannah C.; Bamford, Kathleen B.; Jackson, James E.

2017-01-01

Abstract Background Cerebral abscess is a recognized complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Methods Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with computed tomography–confirmed PAVMs (including 403 [90.5%] with hereditary hemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression was performed and detailed periabscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier nonoverlapping series. Results Thirty-seven of the 445 (8.3%) patients experienced a cerebral abscess at a median age of 50 years (range, 19–76 years). The rate adjusted for ascertainment bias was 27 of 435 (6.2%). Twenty-nine of 37 (78.4%) patients with abscess had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. Twenty-one of 37 (56.7%) suffered residual neurological deficits (most commonly memory/cognition impairment), hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events, emphasized potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio, 5.4 [95% confidence interval, 1.4–21.1]); male sex; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia. Conclusions Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower oxygen saturation and intravenous iron may be modifiable risk factors. PMID

Cerebral Abscess Associated With Odontogenic Bacteremias, Hypoxemia, and Iron Loading in Immunocompetent Patients With Right-to-Left Shunting Through Pulmonary Arteriovenous Malformations.

Science.gov (United States)

Boother, Emily J; Brownlow, Sheila; Tighe, Hannah C; Bamford, Kathleen B; Jackson, James E; Shovlin, Claire L

2017-08-15

Cerebral abscess is a recognized complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with computed tomography-confirmed PAVMs (including 403 [90.5%] with hereditary hemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression was performed and detailed periabscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier nonoverlapping series. Thirty-seven of the 445 (8.3%) patients experienced a cerebral abscess at a median age of 50 years (range, 19-76 years). The rate adjusted for ascertainment bias was 27 of 435 (6.2%). Twenty-nine of 37 (78.4%) patients with abscess had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. Twenty-one of 37 (56.7%) suffered residual neurological deficits (most commonly memory/cognition impairment), hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events, emphasized potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio, 5.4 [95% confidence interval, 1.4-21.1]); male sex; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia. Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower oxygen saturation and intravenous iron may be modifiable risk factors. © The Author 2017. Published by Oxford University Press

Ventriculoperitoneal shunt complications needing shunt revision in children: A review of 5 years of experience with 48 revisions

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Rajendra K Ghritlaharey

2012-01-01

Full Text Available Background: The aim of this study was to review the management of ventriculoperitoneal (VP shunt complications in children. Patients and Methods: During the last 5 years (January 1, 2006 to December 31, 2010, 236 VP shunt operations were performed in children under 12 years of age; of these, 40 (16.94% developed shunt complications and those who underwent VP shunt revisions were studied. Results: This prospective study included 40 (28 boys and 12 girls children and required 48 shunt revisions. Complications following VP shunts that required shunt revisions were peritoneal catheter/peritoneal end malfunction (18, shunt/shunt tract infections (7, extrusion of peritoneal catheter through anus (5, ventricular catheter malfunction (4, cerebrospinal fluid (CSF leak from abdominal wound (4, shunt system failure (2, ventricular end/shunt displacement (2, CSF pseudocysts peritoneal cavity (2, extrusion of peritoneal catheter from neck, chest, abdominal scar and through umbilicus, one each. Four-fifth of these shunt complications occurred within 6 months of previous surgery. Surgical procedures done during shunt revisions in order of frequency were revision of peritoneal part of shunt (27, 56.25%, revision of entire shunt system (6, 12.5%, extra ventricular drainage and delayed re-shunt (5, 10.41%, shunt removal and delayed re-shunt (5, 10.41%, opposite side shunting (2, 4.16%, cysts excision and revision of peritoneal catheter (2, 4.16% and revision of ventricular catheter (1, 2.08%. The mortalities following VP shunt operations were 44 (18.64% and following shunt revisions were 4 (10%. Conclusions: VP shunt done for hydrocephalus in children is not only prone for complications and need for revision surgery but also associated with considerable mortality.

Maturation of arteriovenous fistula: Analysis of key factors

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Muhammad A. Siddiqui

2017-12-01

Full Text Available The growing proportion of individuals suffering from chronic kidney disease has considerable repercussions for both kidney specialists and primary care. Progressive and permanent renal failure is most frequently treated with hemodialysis. The efficiency of hemodialysis treatment relies on the functional status of vascular access. Determining the type of vascular access has prime significance for maximizing successful maturation of a fistula and avoiding surgical revision. Despite the frequency of arteriovenous fistula procedures, there are no consistent criteria applied before creation of arteriovenous fistulae. Increased prevalence and use of arteriovenous fistulae would result if there were reliable criteria to assess which arteriovenous fistulae are more likely to reach maturity without additional procedures. Published studies assessing the predictive markers of fistula maturation vary to a great extent with regard to definitions, design, study size, patient sample, and clinical factors. As a result, surgeons and specialists must decide which possible risk factors are most likely to occur, as well as which parameters to employ when evaluating the success rate of fistula development in patients awaiting the creation of permanent access. The purpose of this literature review is to discuss the role of patient factors and blood markers in the development of arteriovenous fistulae.

Primary ventriculoperitoneal shunting outcomes: a multicentre clinical audit for shunt infection and its risk factors.

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Woo, P Ym; Wong, H T; Pu, J Ks; Wong, W K; Wong, L Yw; Lee, M Wy; Yam, K Y; Lui, W M; Poon, W S

2016-10-01

To determine the frequency of primary ventriculoperitoneal shunt infection among patients treated at neurosurgical centres of the Hospital Authority and to identify underlying risk factors. This multicentre historical cohort study included consecutive patients who underwent primary ventriculoperitoneal shunting at a Hospital Authority neurosurgery centre from 1 January 2009 to 31 December 2011. The primary endpoint was shunt infection, defined as: (1) the presence of cerebrospinal fluid or shunt hardware culture that yielded the pathogenic micro-organism with associated compatible symptoms and signs of central nervous system infection or shunt malfunction; or (2) surgical incision site infection requiring shunt reinsertion (even in the absence of positive culture); or (3) intraperitoneal pseudocyst formation (even in the absence of positive culture). Secondary endpoints were shunt malfunction, defined as unsatisfactory cerebrospinal fluid drainage that required shunt reinsertion, and 30-day mortality. A primary ventriculoperitoneal shunt was inserted in 538 patients during the study period. The mean age of patients was 48 years (range, 13-88 years) with a male-to-female ratio of 1:1. Aneurysmal subarachnoid haemorrhage was the most common aetiology (n=169, 31%) followed by intracranial tumour (n=164, 30%), central nervous system infection (n=42, 8%), and traumatic brain injury (n=27, 5%). The mean operating time was 75 (standard deviation, 29) minutes. Shunt reinsertion and infection rates were 16% (n=87) and 7% (n=36), respectively. The most common cause for shunt reinsertion was malfunction followed by shunt infection. Independent predictors for shunt infection were: traumatic brain injury (adjusted odds ratio=6.2; 95% confidence interval, 2.3-16.8), emergency shunting (2.3; 1.0-5.1), and prophylactic vancomycin as the sole antibiotic (3.4; 1.1-11.0). The 30-day all-cause mortality was 6% and none were directly procedure-related. This is the first Hong Kong

Vasoactive intestinal polypeptide (VIP) in cirrhosis: arteriovenous extraction in different vascular beds

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl; Staun-Olsen, P; Fahrenkrug, J

1980-01-01

The concentration of vasoactive intestinal polypeptide (VIP) was determined in peripheral venous plasma from 136 patients with liver cirrhosis without gastrointestinal bleeding or coma and from 112 controls. In eight patients (cirrhosis, six; fibrosis, one; steatosis, one) arteriovenous extraction...... is significantly elevated in peripheral plasma from patients with cirrhosis, probably due to porto-systemic shunting and/or compromised hepatic elimination. Hepatic elimination is still likely to account for the inactivation of most of the VIP escaping from the neurosynapses throughout the body in patients...

Radiation arteriopathy in the transgenic arteriovenous fistula model.

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Lawton, Michael T; Arnold, Christine M; Kim, Yung J; Bogarin, Ernesto A; Stewart, Campbell L; Wulfstat, Amanda A; Derugin, Nikita; Deen, Dennis; Young, William L

2008-05-01

The transgenic arteriovenous fistula model, surgically constructed with transgenic mouse aorta interposed in common carotid artery-to-external jugular vein fistulae in nude rats, has a 4-month experimental window because patency and transgenic phenotype are lost over time. We adapted this model to investigate occlusive arteriopathy in brain arteriovenous malformations after radiosurgery by radiating grafted aorta before insertion in the fistula. We hypothesized that high-dose radiation would reproduce the arteriopathy observed clinically within the experimental time window and that deletions of endoglin (ENG) and endothelial nitric oxide synthase (eNOS) genes would modify the radiation response. Radiation arteriopathy in the common carotid arteries of 171 wild-type mice was examined with doses of 25, 80, 120, or 200 Gy (Experiment 1). Radiation arteriopathy in 68 wild-type arteriovenous fistulae was examined histologically and morphometrically with preoperative radiation doses of 0, 25, or 200 Gy (Experiment 2). Radiation arteriopathy in 51 transgenic arteriovenous fistulae (36 ENG and 15 eNOS knock-out fistulae) was examined using preoperative radiation doses of 0, 25, or 200 Gy (Experiment 3). High-dose radiation (200 Gy) of mouse common carotid arteries induced only mild arteriopathy (mean score, 0.66) without intimal hyperplasia and with high mortality (68%). Radiation arteriopathy in wild-type arteriovenous fistulae was severe (mean score, 3.5 at 200 Gy), with intimal hyperplasia and medial disruption at 3 months, decreasing luminal areas with increasing dose, and no mortality. Arteriopathy was robust in transgenic arteriovenous fistulae with ENG +/- and with eNOS +/-, with thick intimal hyperplasia in the former and distinct smooth muscle cell proliferation in the latter. The transgenic arteriovenous fistula model can be adapted to rapidly reproduce radiation arteriopathy observed in resected brain arteriovenous malformations after radiosurgery. High

Blood pressure shifts resulting from a concealed arteriovenous fistula associated with an iliac aneurysm: a case report.

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Doi, Shintaro; Motoyama, Yoshiaki; Ito, Hiromi

2016-01-01

A solitary iliac aneurysm (SIA) is more uncommon than an abdominal aortic aneurysm. The aneurysm is located in the deep pelvis and is diagnosed when it reaches a large size with symptoms of compression around adjacent structures and organs or when it ruptures. A definite diagnosis of an arteriovenous fistula (AVF) associated with a SIA is difficult preoperatively because there might not be enough symptoms and time for diagnosis. Here, we present a patient with asymptomatic rupture of SIA into the common iliac vein with characteristic blood pressure shifts. A 41-year-old man with a huge SIA underwent aortobifemoral graft replacement. Preoperatively, his blood pressure showed characteristic shifts for one or two heartbeats out of five beats, indicating that an AVF was present and that the shunt was about to having a high flow. During surgery, an AVF associated with the SIA was found to be concealed owing to compression from the huge iliac artery aneurysm, and the shunt showed a high flow, resulting in shock during the surgery. No complications were noted after aortobifemoral graft replacement. Postoperatively, we noted an enhanced paravertebral vein on computed tomography (CT), which indicated the presence of an AVF. Definite diagnosis of an AVF offers advantages in surgical and anesthetic management. We emphasize that a large SIA can push the iliac vein and occlude an AVF laceration, concealing the enhancement of the veins in the arterial phase on CT. Blood pressure shifts might predict the existence of a concealed AVF that has a large shunt. Even if the vena cava and the iliac veins are not enhanced on CT, anesthesiologists should carefully determine whether their distal branches are enhanced.

Pressure measurements in arterial feeders of brain arteriovenous malformations before and after endovascular embolization

International Nuclear Information System (INIS)

Henkes, H.; Gotwald, T.F.; Brew, S.; Kaemmerer, F.; Miloslavski, E.; Kuehne, D.

2004-01-01

Arteriovenous malformations (AVMs) are composed of abnormal arterial and venous vessels in the brain causing arteriovenous shunts of arterialized blood directly from pial arteries to draining veins. The hemodynamics of these lesions is not well-understood. Changes in blood flow and pressure are probably related to the natural history of AVMs and may also play a major role in AVM treatment. In this study intra-arterial pressure was measured in feeding arteries of AVMs using a microcatheter that had been placed for subsequent embolization treatment (201 measurements were performed in 95 patients before and after the embolization procedure). Results show a direct relationship between pressure changes and degree of embolization. Since pressure changes during the embolization procedure are relatively small, it seems unlikely that these changes are the direct cause of rupture and periprocedural bleedings. (orig.)

Cerebrovascular Accident Secondary to Paradoxical Embolism Following Arteriovenous Graft Thrombectomy

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Jolina Pamela Santos

2012-01-01

Full Text Available Thrombectomy is a common procedure performed to declot thrombosed dialysis arteriovenous fistula (AVF or arteriovenous graft (AVG. Complications associated with access thrombectomy like pulmonary embolism have been reported, but paradoxical embolism is extremely rare. We report a case of a 74-year-old black man with past medical history significant for end-stage renal disease (ESRD, atrial fibrillation on anticoagulation with warfarin, who presented to our hospital with lethargy, aphasia, and right-sided hemiparesis following thrombectomy of a clotted AVG. Computed tomography (CT scan of brain showed a hypodensity within the left posterior parietal lobe. INR was 2.0 on admission. Echocardiogram revealed a normal sized left atrium with no intracardiac thrombus, and bubble study showed the presence of right-to-left shunting. These findings suggest that the stroke occurred as a result of an embolus originating from the AVG. Paradoxical cerebral embolism is uncommon but can occur after thrombectomy of clotted vascular access in ESRD patients. Clinicians and patients should be aware of this serious and potentially fatal complication of vascular access procedure.

Cerebrovascular accident secondary to paradoxical embolism following arteriovenous graft thrombectomy.

Science.gov (United States)

Santos, Jolina Pamela; Hamadeh, Zaher; Ansari, Naheed

2012-01-01

Thrombectomy is a common procedure performed to declot thrombosed dialysis arteriovenous fistula (AVF) or arteriovenous graft (AVG). Complications associated with access thrombectomy like pulmonary embolism have been reported, but paradoxical embolism is extremely rare. We report a case of a 74-year-old black man with past medical history significant for end-stage renal disease (ESRD), atrial fibrillation on anticoagulation with warfarin, who presented to our hospital with lethargy, aphasia, and right-sided hemiparesis following thrombectomy of a clotted AVG. Computed tomography (CT) scan of brain showed a hypodensity within the left posterior parietal lobe. INR was 2.0 on admission. Echocardiogram revealed a normal sized left atrium with no intracardiac thrombus, and bubble study showed the presence of right-to-left shunting. These findings suggest that the stroke occurred as a result of an embolus originating from the AVG. Paradoxical cerebral embolism is uncommon but can occur after thrombectomy of clotted vascular access in ESRD patients. Clinicians and patients should be aware of this serious and potentially fatal complication of vascular access procedure.

Distal splenorenal shunt with partial spleen resection

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Gajin Predrag

2007-01-01

Full Text Available Introduction: Hypersplenism is a common complication of portal hypertension. Cytopenia in hypersplenism is predominantly caused by splenomegaly. Distal splenorenal shunt (Warren with partial spleen resection is an original surgical technique that regulates cytopenia by reduction of the enlarged spleen. Objective. The aim of our study was to present the advantages of distal splenorenal shunt (Warren with partial spleen resection comparing morbidity and mortality in a group of patients treated by distal splenorenal shunt with partial spleen resection with a group of patients treated only by a distal splenorenal shunt. Method. From 1995 to 2003, 41 patients with portal hypertension were surgically treated due to hypersplenism and oesophageal varices. The first group consisted of 20 patients (11 male, mean age 42.3 years who were treated by distal splenorenal shunt with partial spleen resection. The second group consisted of 21 patients (13 male, mean age 49.4 years that were treated by distal splenorenal shunt only. All patients underwent endoscopy and assessment of oesophageal varices. The size of the spleen was evaluated by ultrasound, CT or by scintigraphy. Angiography was performed in all patients. The platelet and white blood cell count and haemoglobin level were registered. Postoperatively, we noted blood transfusion, complications and total hospital stay. Follow-up period was 12 months, with first checkup after one month. Results In the first group, only one patient had splenomegaly postoperatively (5%, while in the second group there were 13 patients with splenomegaly (68%. Before surgery, the mean platelet count in the first group was 51.6±18.3x109/l, to 118.6±25.4x109/l postoperatively. The mean platelet count in the second group was 67.6±22.8x109/l, to 87.8±32.1x109/l postoperatively. Concerning postoperative splenomegaly, statistically significant difference was noted between the first and the second group (p<0.05. Comparing the

Combined spinal intramedullary arteriovenous malformation and lipomyelomeningocele

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Weon, Y.C.; Roh, H.G.; Byun, H.S. [Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiology, Seoul (Korea); Chung, J.I. [Medimoa Hospital, Department of Radiology, Seoul (Korea); Eoh, W. [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea)

2005-10-01

Combined spinal arteriovenous malformation and lipomyelomeningocele are extremely rare. We present a rare combined case of a lipomyelomeningocele with an intramedullary arteriovenous malformation (AVM) occurred at the L3-L4 level in a 30-year-old man who suffered from low back pain radiating to the lower extremities, dysuria, and frequency for 5 years. The MR studies showed an intradural mass with high-signal intensity on both T1-weighted and T2-weighted images, intermingled with multiple signal-void structures. The mass extended extradurally toward a subcutaneously forming fatty mass on the patient's back. Spinal angiography showed an AVM supplied by the radiculopial branches of the lumbar arteries and drained by tortuous, dilated, perimedullary veins. Endovascular embolization and surgical resection were performed. (orig.)

Systemic-pulmonary arteriovenous fistula of traumatic origin: A case report

International Nuclear Information System (INIS)

Hirsch, M.; Maroko, I.; Gueron, M.; Goleman, L.

1983-01-01

Arteriovenous fistulas between the systemic circulation and the pulmonary artery are extremely rare. Continuous precordial murmur is the usual clinical sign while unilateral rib notching may be the only radiologic manifestation of this condition. Selective angiographic investigation is necessary to localize the site of such an arteriovenous (AV) fistula before surgery is performed. In a review of the literature of 15 published cases, the majority were of congenital origin, with four of these systemic-pulmonary AV fistulas of traumatic origin, of which one occurred after insertion of an intercostal catheter. We describe one case of traumatic origin 9 years after percutaneous thoracic drainage for spontaneous pneumothorax, in which transcatheter embolic occlusion of the feeding arteries of an AV fistula was attempted. The advantages and the disadvantages of the non-surgical and surgical therapeutic approaches are discussed. (orig.)

Shunt occlusion for portosystemic shunt syndrome related refractory hepatic encephalopathy-A single-center experience in 21 patients from Kerala.

Science.gov (United States)

Philips, Cyriac Abby; Kumar, Lijesh; Augustine, Philip

2017-09-01

Large spontaneous portosystemic shunts (SPSS) are seen in a subset of patients with liver disease and medically refractory recurrent/persistent hepatic encephalopathy (MRHE). Shunt occlusion has been shown to improve clinical outcomes. We retrospectively analyzed patient characteristics, SPSS attributes, procedural features, baseline clinical and investigational parameters, neurological outcomes, adverse effects (procedure and portal hypertension related), and risk factors predicting outcomes in liver disease patients undergoing shunt occlusion procedure for MRHE. Between October 2016 and July 2017, 21 patients (Child-Pugh score, CTP 6 to 13) with mean model of end-stage liver disease (MELD) and MELD-sodium scores 15.7 and 19.3 respectively with MRHE [3-cirrhotic Parkinsonism (CP)] were diagnosed to have single or multiple large SPSSs. A total of 29 shunts were occluded (1 surgical, 20 non-surgical). Recurrent and persistent HE and CP markedly improved in the short (n=20, 1 to 3 months), intermediate (n=12, 3 to 6 months), and long (n=7, 6 to 9 months) follow up. None had spontaneous or persistent HE at a median follow up 105 (30 to 329) days (p11 predicted mortality post shunt occlusion (p=0.04). Embolization of large SPSS in liver disease patients with MRHE and modestly preserved liver function is safe and efficacious and associated with improved quality of life and can function as a bridge to liver transplantation in accurately selected patients.

Pulmonary arteriovenous malformations: overview and transcatheter embolotherapy

International Nuclear Information System (INIS)

Pugash, R.A.

2001-01-01

The majority of pulmonary arteriovenous malformations (pAVMs) are found in people with hereditary hemorrhagic telangiectasia (HHT), a condition also known as Osler-Weber-Rendu syndrome. HHT is a clinically heterogeneous autosomal dominant disorder in which abnormal blood vessels cause bleeding and arteriovenous shunting. The 2 basic lesions of HHT - telangiectasias and arteriovenous malformations (AVMs) - are closely related. Multisystem involvement leads to a staggering array of clinical manifestations, making HHT one of medicine's less familiar 'great pretenders'. Telangiectasias are dilated blood vessels, typically located in mucocutaneous surfaces (i.e., skin, conjunctiva, respiratory tract, gastrointestinal tract, urinary tract). Small telangiectasias are simply dilated post-capillary venules, whereas larger telangiectasias are made up of dilated arterioles and venules, often with no intervening capillary. They are, in essence, diminutive AVMs. These tiny lesions are visible as punctate bright red spots on skin and mucosal surfaces (Fig. 1). Their fragility and superficial location account for the disabling epistaxis and chronic gastrointestinal bleeding, which are so common with HHT. Hematuria (caused by urothelial telangiectasias) occurs occasionally but is not a prominent feature of the disease. Although tracheobronchial telangiectasias do occur and may cause hemoptysis, severe hemoptysis is typically related to pAVM rupture. AVMs are direct artery-to-vein connections. Though larger and far more impressive radiologically than telangiectasias, AVMs are more likely to be clinically silent until they either declare themselves in a catastrophic fashion or are detected by screening tests. In contrast to telangiectasias, which are generally found in epithelial surfaces, AVMs tend to develop within organs, most commonly the lung and brain. As screening methods evolve, liver involvement with both telangiectasias and complex AVMs is being recognized with increasing

Pulmonary arteriovenous malformations: overview and transcatheter embolotherapy

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Pugash, R.A. [Univ. of Toronto, St. Michael' s Hospital, Dept. of Medical Imaging, Toronto, Ontario (Canada)

2001-04-01

The majority of pulmonary arteriovenous malformations (pAVMs) are found in people with hereditary hemorrhagic telangiectasia (HHT), a condition also known as Osler-Weber-Rendu syndrome. HHT is a clinically heterogeneous autosomal dominant disorder in which abnormal blood vessels cause bleeding and arteriovenous shunting. The 2 basic lesions of HHT - telangiectasias and arteriovenous malformations (AVMs) - are closely related. Multisystem involvement leads to a staggering array of clinical manifestations, making HHT one of medicine's less familiar 'great pretenders'. Telangiectasias are dilated blood vessels, typically located in mucocutaneous surfaces (i.e., skin, conjunctiva, respiratory tract, gastrointestinal tract, urinary tract). Small telangiectasias are simply dilated post-capillary venules, whereas larger telangiectasias are made up of dilated arterioles and venules, often with no intervening capillary. They are, in essence, diminutive AVMs. These tiny lesions are visible as punctate bright red spots on skin and mucosal surfaces (Fig. 1). Their fragility and superficial location account for the disabling epistaxis and chronic gastrointestinal bleeding, which are so common with HHT. Hematuria (caused by urothelial telangiectasias) occurs occasionally but is not a prominent feature of the disease. Although tracheobronchial telangiectasias do occur and may cause hemoptysis, severe hemoptysis is typically related to pAVM rupture. AVMs are direct artery-to-vein connections. Though larger and far more impressive radiologically than telangiectasias, AVMs are more likely to be clinically silent until they either declare themselves in a catastrophic fashion or are detected by screening tests. In contrast to telangiectasias, which are generally found in epithelial surfaces, AVMs tend to develop within organs, most commonly the lung and brain. As screening methods evolve, liver involvement with both telangiectasias and complex AVMs is being recognized

Ischaemic strokes in patients with pulmonary arteriovenous malformations and hereditary hemorrhagic telangiectasia: associations with iron deficiency and platelets.

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Claire L Shovlin

Full Text Available BACKGROUND: Pulmonary first pass filtration of particles marginally exceeding ∼7 µm (the size of a red blood cell is used routinely in diagnostics, and allows cellular aggregates forming or entering the circulation in the preceding cardiac cycle to lodge safely in pulmonary capillaries/arterioles. Pulmonary arteriovenous malformations compromise capillary bed filtration, and are commonly associated with ischaemic stroke. Cohorts with CT-scan evident malformations associated with the highest contrast echocardiographic shunt grades are known to be at higher stroke risk. Our goal was to identify within this broad grouping, which patients were at higher risk of stroke. METHODOLOGY: 497 consecutive patients with CT-proven pulmonary arteriovenous malformations due to hereditary haemorrhagic telangiectasia were studied. Relationships with radiologically-confirmed clinical ischaemic stroke were examined using logistic regression, receiver operating characteristic analyses, and platelet studies. PRINCIPAL FINDINGS: Sixty-one individuals (12.3% had acute, non-iatrogenic ischaemic clinical strokes at a median age of 52 (IQR 41-63 years. In crude and age-adjusted logistic regression, stroke risk was associated not with venous thromboemboli or conventional neurovascular risk factors, but with low serum iron (adjusted odds ratio 0.96 [95% confidence intervals 0.92, 1.00], and more weakly with low oxygen saturations reflecting a larger right-to-left shunt (adjusted OR 0.96 [0.92, 1.01]. For the same pulmonary arteriovenous malformations, the stroke risk would approximately double with serum iron 6 µmol/L compared to mid-normal range (7-27 µmol/L. Platelet studies confirmed overlooked data that iron deficiency is associated with exuberant platelet aggregation to serotonin (5HT, correcting following iron treatment. By MANOVA, adjusting for participant and 5HT, iron or ferritin explained 14% of the variance in log-transformed aggregation-rate (p = 0

Polyvinyl alcohol terminal chemoembolization for hepatocellular carcinoma with hepatic arteriovenous shunts: Safety, efficacy, and prognostic factors

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Liu, Qiu-song; Mei, Que-lin; Li, Yan-hao, E-mail: cjr.liyanhao@vip.163.com

2017-04-15

Purpose: To evaluate the safety and efficacy of polyvinyl alcohol (PVA) terminal chemoembolization and to identify the prognostic factors associated with survival in hepatocellular carcinoma (HCC) patients with hepatic arteriovenous shunts (HAVS). Materials and methods: Of 133 patients’ managements were retrospectively analyzed. HAVS was classified into three types: slow-flow, intermediate-flow and high-flow. The size of the PVA used was determined following the scheme: slow-flow HAVS: 300–500 μm PVA; intermediate-flow HAVS: 500–710 μm PVA; high-flow HAVS: 710–1000 μm PVA. The HCCs with slow-flow and intermediate-flow HAVS were embolized by PVA plus chemotherapeutic agents lipiodol emulsion, while the high-flow HAVS were treated by PVA with chemotherapeutic agents. Survival curves were calculated by Kaplan-Meier method and compared by log-rank test. The influence of possible prognostic factors on survival were analyzed by multivariate Cox proportional-hazards method. Results: The median overall survival (OS) of 133 patients was 9.1 months. The median OS of the slow-flow type, intermediate-flow type and high-flow type patients were 10.8, 9.1 and 7.3 months, respectively. There was no statistically significant difference among different HAVS types (P = 0.239). The 30-day mortality was 3.8%. Cox multivariate survival analysis revealed that initial preoperative AFP value ≥ 400 ng/ml (HR = 2.105, P = 0.006) was an independent risk factor. While multiple embolization (HR = 0.482, P = 0.011), tumor remission (HR = 0.431, P = 0.041) and multimodality therapy (HR = 0.416, P = 0.004) were independent protection factors. Conclusion: It is safe and effective for HCCs with HAVS treated by terminal chemoembolization therapy with PVA plus chemotherapeutic agents lipiodol emulsion (or PVA plus chemotherapeutic agents). The HCCs with HAVS achieves good prognosis with multiple embolization, tumor remission and multimodality therapy, while achieves poor prognosis with

Portosystemic shunts for extrahepatic portal hypertension in children.

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Tocornal, J; Cruz, F

1981-07-01

Twenty-three children with prehepatic portal hypertension and hemorrhage due to ruptured esophagogastric varices had portosystemic shunts. Their ages ranged from two years and seven months to 15 years. Eleven were less than eight years of age. Twenty patients had portal vein cavernomatosis and three patients had double portal veins. In 21 patients, a mesocaval type of shunt was done. A splenorenal shunt was performed in two. There was no surgical mortality. Two shunts occluded, both in rather young infants--two years and seven months and three years of age. In all the others, there was no further bleeding, and the shunts remained patent, as shown by abdominal angiograms. Neuropsychiatric disorders, probably due to hepatic encephalopathy, occurred in only one patient. On the basis of this favorable experience, we believe that an elective portosystemic shunt should, in general, be performed upon children with prehepatic portal hypertension after one major variceal hemorrhage. We favor a mesocaval type of shunt in these children because of the larger diameter of the vessels involved in the anastomosis and because it preserves the spleen, maintaining defense against subsequent infection.

Creation of transcatheter aortopulmonary and cavopulmonary shunts using magnetic catheters: feasibility study in swine.

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Levi, Daniel S; Danon, Saar; Gordon, Brent; Virdone, Nicky; Vinuela, Fernando; Shah, Sanjay; Carman, Greg; Moore, John W

2009-05-01

Surgical shunts are the basic form of palliation for many types of congenital heart disease. The Glenn shunt (superior cavopulmonary connection) and central shunt (aortopulmonary connection) represent surgical interventions that could potentially be accomplished by transcatheter techniques. We sought to investigate the efficacy of using neodymium iron boron (NdFeB) magnetic catheters to create transcatheter cavopulmonary and aortopulmonary shunts. NdFeB magnets were machined and integrated into catheters. "Target" catheters were placed in the pulmonary arteries (PAs), and radiofrequency "perforation" catheters were placed in either the descending aorta (DAo) for central shunts or the superior vena cava (SVC) for Glenn shunts. The magnet technique or "balloon target" method was used to pass wires from the DAo or the SVC into the PA. Aortopulmonary and cavopulmonary connections were then created using Atrium iCAST covered stents. Magnet catheters were used to perforate the left pulmonary artery from the DAo, thereby establishing a transcatheter central shunt. Given the orientation of the vasculature, magnetic catheters could not be used for SVC-to-PA connections; however, perforation from the SVC to the right pulmonary artery was accomplished with a trans-septal needle and balloon target. Transcatheter Glenn or central shunts were successfully created in four swine.

An unusual case of fistula formation and thrombosis between arteriovenous graft and a native vein

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Young Sub Kim

2016-03-01

Full Text Available Arteriovenous graft for hemodialysis vascular access is a widely used technique with many advantages. However, it has crucial complications with graft thrombosis and infection. We recently experienced an unusual case of arteriovenous graft complication involving graft thrombosis related to fistula formation between the graft and the natural vein with infection. We diagnosed this condition using Doppler ultrasound and computed tomography angiography. Successful surgical treatment including partial graft excision and creation of a secondary arteriovenous fistula using an inadvertently dilated cephalic vein was performed. The dialysis unit staff should keep this condition in mind and try to prevent this complication.

Characteristics, diagnosis and treatment of hypoglossal canal dural arteriovenous fistula: report of nine cases

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Manabe, Shinji; Satoh, Koichi; Matsubara, Shunji; Satomi, Junichiro; Hanaoka, Mami; Nagahiro, Shinji [University of Tokushima, Department of Neurosurgery, Tokushima (Japan)

2008-08-15

We report the characteristics, diagnosis and treatment of dural arteriovenous fistula (DAVF) of the hypoglossal canal in nine patients with this relatively rare vascular disorder. Of 248 patients with intracranial DAVFs managed at our institution, nine patients (3.6%; four men, five women; mean age 62 years) were diagnosed with hypoglossal canal DAVF. We investigated patient characteristics with respect to clinical symptoms, neuroradiological findings, efficacy and complications related to endovascular treatment. Seven patients had experienced head injury. All patients presented with pulsatile tinnitus. One patient displayed ipsilateral hypoglossal nerve palsy before treatment. MR angiography showed a 'magic wand' appearance between the affected hypoglossal canal and the internal jugular vein in four patients. Angiography demonstrated an AV fistula on the medial aspect of the superior jugular bulb, mostly arising from the bilateral occipital, ascending pharyngeal and vertebral arteries with drainage to the internal jugular vein via the anterior condylar vein. Contralateral carotid injection accurately clarified the shunting point. Five patients underwent endovascular treatment: transarterial embolization (TAE; n=2), transvenous embolization (TVE; n=2), and TAE/TVE (n=1). Complete shunt obliteration was achieved in four patients and shunt reduction in one. The remaining four patients were treated conservatively and the shunt had disappeared at follow-up. Postoperative hypoglossal nerve palsy occurred in one patient after TVE, possibly due to coil overpacking. The incidence of hypoglossal canal DAVF was not very low in our series. Contralateral carotid injection is an essential examination to provide an accurate diagnosis. TVE should be considered when access is available, although TAE is also appropriate for shunt reduction. (orig.)

Characteristics, diagnosis and treatment of hypoglossal canal dural arteriovenous fistula: report of nine cases

International Nuclear Information System (INIS)

Manabe, Shinji; Satoh, Koichi; Matsubara, Shunji; Satomi, Junichiro; Hanaoka, Mami; Nagahiro, Shinji

2008-01-01

We report the characteristics, diagnosis and treatment of dural arteriovenous fistula (DAVF) of the hypoglossal canal in nine patients with this relatively rare vascular disorder. Of 248 patients with intracranial DAVFs managed at our institution, nine patients (3.6%; four men, five women; mean age 62 years) were diagnosed with hypoglossal canal DAVF. We investigated patient characteristics with respect to clinical symptoms, neuroradiological findings, efficacy and complications related to endovascular treatment. Seven patients had experienced head injury. All patients presented with pulsatile tinnitus. One patient displayed ipsilateral hypoglossal nerve palsy before treatment. MR angiography showed a ''magic wand'' appearance between the affected hypoglossal canal and the internal jugular vein in four patients. Angiography demonstrated an AV fistula on the medial aspect of the superior jugular bulb, mostly arising from the bilateral occipital, ascending pharyngeal and vertebral arteries with drainage to the internal jugular vein via the anterior condylar vein. Contralateral carotid injection accurately clarified the shunting point. Five patients underwent endovascular treatment: transarterial embolization (TAE; n=2), transvenous embolization (TVE; n=2), and TAE/TVE (n=1). Complete shunt obliteration was achieved in four patients and shunt reduction in one. The remaining four patients were treated conservatively and the shunt had disappeared at follow-up. Postoperative hypoglossal nerve palsy occurred in one patient after TVE, possibly due to coil overpacking. The incidence of hypoglossal canal DAVF was not very low in our series. Contralateral carotid injection is an essential examination to provide an accurate diagnosis. TVE should be considered when access is available, although TAE is also appropriate for shunt reduction. (orig.)

Treatment of refractory chylothorax with externalized pleuroperitoneal shunts in children.

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Wolff, A B; Silen, M L; Kokoska, E R; Rodgers, B M

1999-09-01

Traditional therapy for refractory chylothorax in the pediatric population has included pleurodesis and thoracic duct ligation. These procedures are associated with high morbidity and questionable success rates. We retrospectively reviewed our experience with 15 patients who underwent treatment for chylous effusions using pleuroperitoneal shunts with exteriorized pump chambers. Mean patient age at time of shunt placement was 2.1 (0.1 to 11.5) years and the most common indication (7 of 15) was refractory chylothorax following surgical correction of congenital heart disease. Mean chylothorax duration before shunt placement was 76 (5 to 810) days and shunts were in place for an average of 104 (12 to 365) days. A total of 19 chylous effusions (pleural or pericardial) were treated with shunts. Nine of 11 right-sided chylothoraces, 5 of 6 left-sided chylothoraces, and 2 of 2 chylopericardia resolved with shunt therapy (84% total). Pleuroperitoneal shunting failed to clear the effusion in 3 children. There were six episodes of shunt malfunction that were repaired and two episodes of infection. Inguinal or umbilical hernia developed in 4 patients. Externalized pleuroperitoneal shunting is a safe, effective, and minimally invasive treatment for children with refractory chylous effusions.

Peroneal Arteriovenous Fistula and Pseudoaneurysm: An Unusual Presentation

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Kevin C. Ching

2014-01-01

Full Text Available Peroneal artery arteriovenous fistulas and pseudoaneurysms are extremely rare with the majority of reported cases due to penetrating, orthopedic, or iatrogenic trauma. Failure to diagnose this unusual vascular pathology may lead to massive hemorrhage or limb threatening ischemia. We report an interesting case of a 14-year-old male who presented with acute musculoskeletal pain of his lower extremity. Initial radiographs were negative. Further imaging workup revealed a peroneal arteriovenous fistula with a large pseudoaneurysm. After initial endovascular intervention was unsuccessful, the vessels were surgically ligated in the operating room. Pathology revealed papillary endothelial hyperplasia consistent with an aneurysm and later genetic testing was consistent with Ehlers-Danlos syndrome Type IV. This case illustrates an unusual cause of acute atraumatic musculoskeletal pain and uncommon presentation of Ehlers-Danlos syndrome.

Endoscopic Third Ventriculostomy in Previously Shunted Children

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Eva Brichtova

2013-01-01

Full Text Available Endoscopic third ventriculostomy (ETV is a routine and safe procedure for therapy of obstructive hydrocephalus. The aim of our study is to evaluate ETV success rate in therapy of obstructive hydrocephalus in pediatric patients formerly treated by ventriculoperitoneal (V-P shunt implantation. From 2001 till 2011, ETV was performed in 42 patients with former V-P drainage implantation. In all patients, the obstruction in aqueduct or outflow parts of the fourth ventricle was proved by MRI. During the surgery, V-P shunt was clipped and ETV was performed. In case of favourable clinical state and MRI functional stoma, the V-P shunt has been removed 3 months after ETV. These patients with V-P shunt possible removing were evaluated as successful. In our group of 42 patients we were successful in 29 patients (69%. There were two serious complications (4.7%—one patient died 2.5 years and one patient died 1 year after surgery in consequence of delayed ETV failure. ETV is the method of choice in obstructive hydrocephalus even in patients with former V-P shunt implantation. In case of acute or scheduled V-P shunt surgical revision, MRI is feasible, and if ventricular system obstruction is diagnosed, the hydrocephalus may be solved endoscopically.

Autologous patch graft in tube shunt surgery.

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Aslanides, I M; Spaeth, G L; Schmidt, C M; Lanzl, I M; Gandham, S B

1999-10-01

To evaluate an alternate method of covering the subconjunctival portion of the tube in aqueous shunt surgery. Evidence of tube erosion, graft-related infection, graft melting, or other associated intraocular complications were evaluated. A retrospective study of 16 patients (17 eyes) who underwent tube shunt surgery at Wills Eye Hospital between July 1991 and October 1996 was conducted. An autologous either "free" or "rotating" scleral lamellar graft was created to cover the subconjunctival portion of the tube shunt. All patients were evaluated for at least 6 months, with a mean follow-up of 14.8 months (range 6-62 months). All eyes tolerated the autologous graft well, with no clinical evidence of tube erosion, or graft-related or intraocular complications. Autologous patch graft in tube shunt surgery appears--in selected cases--to be an effective, safe and inexpensive surgical alternative to allogenic graft materials. It also offers ease of availability, and eliminates the risk of transmitting infectious disease.

Maintenance of vascular access patency in pediatrics

International Nuclear Information System (INIS)

Hoffer, F.A.; Wyly, J.B.; Fellows, K.E.; Harmon, W.; Levey, R.H.

1986-01-01

The patency of vascular access shunts and fistulae has been prolonged by a combined surgical and radiological approach that includes percutaneous transluminal angioplasty (PTA), surgical revision, thrombectomy, and thrombolysis. Over the last 3 years, 35 vascular accesses in 27 patients were found to have angiographic abnormality. PTA was performed 32 times of 19 accesses and 7 PTAs resulted in patent accesses by the end of the study. Surgical revision was performed 9 times on 8 accesses and 2 of the surgical revisions resulted in a patent access by the end of the study. Concerning Thomas femoral shunts, PTA prolonged the patency by 2.2 months and surgical revision by 3.8 months per procedure. Concerning arteriovenous (AV) fistulae, PTA prolonged the patency by 4.3 months and surgical revision by 3.5 months per procedure. A combination of procedures effectively doubles the duration of patency of Thomas femoral shunts and almost triples the duration of patency of AV fistulae in children. Forty-one percent of these accesses remain open 1 year following the initiation of these procedures. (orig.)

Staged Transcatheter Treatment of Portal Hypoplasia and Congenital Portosystemic Shunts in Children

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Bruckheimer, Elchanan, E-mail: elchananb@bezeqint.net; Dagan, Tamir [Schneider Children' s Medical Center Israel, Section of Pediatric Cardiology (Israel); Atar, Eli; Schwartz, Michael [Schneider Children' s Medical Center Israel, Section of Radiology (Israel); Kachko, Ludmila [Schneider Children' s Medical Center Israel, Section of Anesthesiology (Israel); Superina, Riccardo; Amir, Gabriel [Schneider Children' s Medical Center Israel, Section of Pediatric Cardiology (Israel); Shapiro, Rivka [Schneider Children' s Medical Center Israel, Section of Gastroenterology (Israel); Birk, Einat [Schneider Children' s Medical Center Israel, Section of Pediatric Cardiology (Israel)

2013-12-15

Purpose: Congenital portosystemic shunts (CPSS) with portal venous hypoplasia cause hyperammonemia. Acute shunt closure results in portal hypertension. A transcatheter method of staged shunt reduction to afford growth of portal vessels followed by shunt closure is reported. Methods: Pressure measurements and angiography in the CPSS or superior mesenteric artery (SMA) during temporary occlusion of the shunt were performed. If vessels were diminutive and the pressure was above 18 mmHg, a staged approach was performed, which included implantation of a tailored reducing stent to reduce shunt diameter by {approx}50 %. Recatheterization was performed approximately 3 months later. If the portal pressure was below 18 mmHg and vessels had developed, the shunt was closed with a device. Results: Six patients (5 boys, 1 girl) with a median age of 3.3 (range 0.5-13) years had CPSS portal venous hypoplasia and hyperammonemia. Five patients underwent staged closure. One patient tolerated acute closure. One patient required surgical shunt banding because a reducing stent could not be positioned. At median follow-up of 3.8 (range 2.2-8.4) years, a total of 21 procedures (20 transcatheter, 1 surgical) were performed. In all patients, the shunt was closed with a significant reduction in portal pressure (27.7 {+-} 11.3 to 10.8 {+-} 1.8 mmHg; p = 0.016), significant growth of the portal vessels (0.8 {+-} 0.5 to 4.0 {+-} 2.4 mm; p = 0.037), and normalization of ammonia levels (202.1 {+-} 53.6 to 65.7 {+-} 9.6 {mu}mol/L; p = 0.002) with no complications. Conclusion: Staged CPSS closure is effective in causing portal vessel growth and treating hyperammonemia.

Timing, severity of deficits, and clinical improvement after surgery for spinal dural arteriovenous fistulas.

Science.gov (United States)

Safaee, Michael M; Clark, Aaron J; Burkhardt, Jan-Karl; Winkler, Ethan A; Lawton, Michael T

2018-04-20

OBJECTIVE Spinal dural arteriovenous fistulas (dAVFs) are rare vascular abnormalities caused by arteriovenous shunting. They often form at the dural root sleeve between a radicular feeding artery and draining medullary vein causing venous congestion and edema, decreased perfusion, and ischemia of the spinal cord. Treatment consists of either surgical ligation of the draining vein or selective embolization via an endovascular approach. There is a paucity of data on which modality provides more durable and effective outcomes. METHODS The authors performed a retrospective review of a prospectively maintained database by the senior author to assess clinical outcomes in patients undergoing surgical treatment of spinal dAVFs. Preoperative and postoperative motor and Aminoff-Logue Scale (ALS) scores were collected. RESULTS A total of 41 patients with 44 spinal dAVFs were identified, with a mean patient age of 64 years. The mean symptom duration was 14 months, with weakness (82%), urinary symptoms (47%), and sensory symptoms (29%) at presentation. The fistula locations were as follows: 30 thoracic, 9 lumbar, 3 sacral, and 2 cervical. Five patients had normal motor and ALS scores at presentation. Among the remaining 36 patients with motor deficits or abnormal gait and micturition at presentation, 78% experienced an improvement while the remaining 22% continued to be stable. There was a trend toward improved outcomes in patients with shorter symptom duration; mean symptom duration among patients with clinical improvement was 13 months compared with 22 months among those without improvement. Additionally, rates of improvement were higher for lower thoracic and lumbosacral dAVFs (85% and 83%) compared with those in the upper thoracic spine (57%). No patient developed recurrent fistulas or worsening neurological deficits. CONCLUSIONS Surgery is associated with excellent outcomes in the treatment of spinal dAVFs. Early diagnosis and treatment are critical, with a trend toward

Treatment of Occluded Distal Splenorenal Shunts with Endovascular Stents: A Report of Two Cases

International Nuclear Information System (INIS)

Lopez-Medina, Antonio; Peiro, Javier; Gonzalez de Garay, Miguel; Antonana, Miguel A.; Sustacha, Jon; Grande, Domingo

2001-01-01

Surgical treatment of an occluded or stenotic portosystemic shunt is difficult and carries a high risk of mortality. We report two cases of early thrombosis of distal splenorenal shunt (DSRS) successfully treated by transcatheter recanalization and stent placement. At 18-month follow-up, the patients remained asymptomatic and control venograms showed continued patency of the shunt with no evidence of stenosis or collaterals

Non-matured arteriovenous fistulae for haemodialysis: diagnosis, endovascular and surgical treatment

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Marko Malovrh

2010-04-01

Full Text Available Non-maturation is a feature of autologous vascular access. The autologous arteriovenous fistula needs time to mature and for the vein to enlarge to a size where it can be needled for dialysis. A fistula that fails early is one that either never develops adequately to support dialysis or fails within the first three months of its use. Two variables are required for fistula maturation. Firstly, the fistula should have adequate blood flow to support dialysis and secondly, it should have enough size to allow for successful repetitive cannulation. Three main reasons for maturation failure are: arterial and venous problems and the presence of accessory veins. Early diagnostics and intervention for fistula maturation minimizes catheter use and its associated complications. The identification of immature fistulae is relatively simple. Physical examination has been highlighted to be a valuable tool in assessing fistula. Any fistula that fails to mature adequately and demonstrates abnormal physical findings should be studied aggressively. Ultrasonography can successfully identify candidates who fail to meet the recently developed criteria for immature fistulae. In recent years, digital subtraction angiography and contrast-enhanced magnetic resonance angiography has been introduced for assessment of dysfunctional haemodialysis conduits, including immature fistulae. A great majority of non-matured fistulae can be successfully salvaged using percutaneous techniques. In addition to endovascular techniques, surgical intervention can also be an option. This paper reviews the process of fistula maturation and presents information regarding how to obtain a mature fistula.

Treatment of Portosystemic Shunt Myelopathy with a Stent Graft Deployed through a Transjugular Intrahepatic Route

International Nuclear Information System (INIS)

Jain, Deepak; Arora, Ankur; Deka, Pranjal; Mukund, Amar; Bhatnagar, Shorav; Jindal, Deepti; Kumar, Niteen; Pamecha, Viniyendra

2013-01-01

A case of surgically created splenorenal shunt complicated with shunt myelopathy was successfully managed by placement of a stent graft within the splenic vein to close the portosystemic shunt and alleviate myelopathy. To our knowledge, this is the first report of a case of shunt myelopathy in a patient with noncirrhotic portal fibrosis without cirrhosis treated by a novel technique wherein a transjugular intrahepatic route was adopted to deploy the stent graft

Arteriovenous malformation of the external ear: a clinical assessment with a scoping review of the literature

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Shin Hye Kim

Full Text Available Abstract Introduction: Auricular Arteriovenous Malformation of the external ear is a rarely encountered disease; in particular, arteriovenous malformation arising from the auricle, with spontaneous bleeding, has seldom been reported. Objective: In the current study, we report an unusual case of late-onset auricular arteriovenous malformation originating from the posterior auricular artery that was confirmed by computed tomographic angiography. The case was successfully managed by pre-surgical intravascular embolization followed by total lesion excision. Prompted by this case, we also present a scoping review of the literature. Methods: A case of a 60 year-old man with right auricular arteriovenous malformation treated in our tertiary care center, and 52 patients with auricular arteriovenous malformation described in 10 case reports and a retrospective review are presented. Auricular arteriovenous malformation can manifest as swelling of the ear, pulsatile tinnitus, pain, and/or bleeding. On physical examination, a pulsatile swelling and/or a tender mass is evident. When arteriovenous malformation is suspected, the lesions should be visualized using imaging modalities that optimally detect vascular lesions, and managed via embolization, mass excision, or auricular resection. Effectiveness of the various diagnostic methods used and the treatment outcomes were analyzed. Results: Various imaging modalities including Doppler sonography, computed tomographic angiography, magnetic resonance angiography, and/or transfemoral cerebral angiography were used to diagnose 38 cases reported in the literature. In another 15 cases, no imaging was performed; treatment was determined solely by physical examination and auscultation. Of the total of 53 cases, 12 were not treated (their symptoms were merely observed whereas 20 underwent therapeutic embolization. In total, 32 patients, including 1 patient who was not treated and 10 with persistent or aggravated

Morphology of congenital portosystemic shunts involving the left colic vein in dogs and cats.

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White, R N; Parry, A T

2016-05-01

To describe the anatomy of congenital portosystemic shunts involving the left colic vein in dogs and cats. Retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. For inclusion a shunt involving the left colic vein with recorded intraoperative mesenteric portovenography or computed tomography angiography along with direct gross surgical observations at the time of surgery was required. Six dogs and three cats met the inclusion criteria. All cases had a shunt which involved a distended left colic vein. The final communication with a systemic vein was variable; in seven cases (five dogs, two cats) it was via the caudal vena cava, in one cat it was via the common iliac vein and in the remaining dog it was via the internal iliac vein. In addition, two cats showed caudal vena cava duplication. The morphology of this shunt type appeared to be a result of an abnormal communication between either the left colic vein or the cranial rectal vein and a pelvic systemic vein (caudal vena cava, common iliac vein or internal iliac vein). This information may help with surgical planning in cases undergoing shunt closure surgery. © 2016 British Small Animal Veterinary Association.

Radiosurgery for brain arteriovenous malformations

International Nuclear Information System (INIS)

Latorzeff, I.; Schlienger, M.; Sabatier, J.; Borius, P.Y.; Lotterie, J.A.; Bourdin, S.; Menegalli, D.; Cognard, C.; Januel, A.C.; Desal, H.; Debono, B.; Blond, S.

2012-01-01

Radiosurgery as treatment for arteriovenous malformations has shown a good efficacy in reducing intracranial bleeding due to rupture. The choice of therapeutic modalities is based on evolutive risk and arteriovenous malformations volume, patient profile and risks stratification following therapeutic techniques (microsurgery, radiosurgery, embolization). Nidus size, arteriovenous malformations anatomical localization, prior embolization or bleeding, distributed dose are predictive factors for radio-surgery's good results and tolerance. This review article will highlight arteriovenous malformations radiosurgery indications and discuss recent irradiation alternatives for large arteriovenous malformation volumes. (authors)

Controversies: Optic nerve sheath fenestration versus shunt placement for the treatment of idiopathic intracranial hypertension

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Arielle Spitze

2014-01-01

Full Text Available Background: Idiopathic intracranial hypertension (IIH has been increasing in prevalence in the past decade, following the obesity epidemic. When medical treatment fails, surgical treatment options must be considered. However, controversy remains as to which surgical procedure is the preferred surgical option - optic nerve sheath fenestration (ONSF or cerebrospinal fluid (CSF shunting - for the long-term treatment of this syndrome. Purpose: To provide a clinical update of the pros and cons of ONSF versus shunt placement for the treatment of IIH. Design: This was a retrospective review of the current literature in the English language indexed in PubMed. Methods: The authors conducted a PubMed search using the following terms: Idiopathic IIH, pseudotumor cerebri, ONSF, CSF shunts, vetriculo-peritoneal shunting, and lumbo-peritoneal shunting. The authors included pertinent and significant original articles, review articles, and case reports, which revealed the new aspects and updates in these topics. Results: The treatment of IIH remains controversial and lacks randomized controlled clinical trial data. Treatment of IIH rests with the determination of the severity of IIH-related visual loss and headache. Conclusion: The decision for ONSF versus shunting is somewhat institution and surgeon dependent. ONSF is preferred for patients with visual symptoms whereas shunting is reserved for patients with headache. There are positive and negative aspects of both procedures, and a prospective, randomized, controlled trial is needed (currently underway. This article will hopefully be helpful in allowing the reader to make a more informed decision until that time.

Characteristics, diagnosis and treatment of hypoglossal canal dural arteriovenous fistula: report of nine cases

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Manabe, Shinji; Satoh, Koichi; Matsubara, Shunji; Satomi, Junichiro; Hanaoka, Mami; Nagahiro, Shinji [University of Tokushima, Department of Neurosurgery, Tokushima (Japan)

2008-08-15

We report the characteristics, diagnosis and treatment of dural arteriovenous fistula (DAVF) of the hypoglossal canal in nine patients with this relatively rare vascular disorder. Of 248 patients with intracranial DAVFs managed at our institution, nine patients (3.6%; four men, five women; mean age 62 years) were diagnosed with hypoglossal canal DAVF. We investigated patient characteristics with respect to clinical symptoms, neuroradiological findings, efficacy and complications related to endovascular treatment. Seven patients had experienced head injury. All patients presented with pulsatile tinnitus. One patient displayed ipsilateral hypoglossal nerve palsy before treatment. MR angiography showed a 'magic wand' appearance between the affected hypoglossal canal and the internal jugular vein in four patients. Angiography demonstrated an AV fistula on the medial aspect of the superior jugular bulb, mostly arising from the bilateral occipital, ascending pharyngeal and vertebral arteries with drainage to the internal jugular vein via the anterior condylar vein. Contralateral carotid injection accurately clarified the shunting point. Five patients underwent endovascular treatment: transarterial embolization (TAE; n=2), transvenous embolization (TVE; n=2), and TAE/TVE (n=1). Complete shunt obliteration was achieved in four patients and shunt reduction in one. The remaining four patients were treated conservatively and the shunt had disappeared at follow-up. Postoperative hypoglossal nerve palsy occurred in one patient after TVE, possibly due to coil overpacking. The incidence of hypoglossal canal DAVF was not very low in our series. Contralateral carotid injection is an essential examination to provide an accurate diagnosis. TVE should be considered when access is available, although TAE is also appropriate for shunt reduction. (orig.)

Staged Transcatheter Treatment of Portal Hypoplasia and Congenital Portosystemic Shunts in Children

International Nuclear Information System (INIS)

Bruckheimer, Elchanan; Dagan, Tamir; Atar, Eli; Schwartz, Michael; Kachko, Ludmila; Superina, Riccardo; Amir, Gabriel; Shapiro, Rivka; Birk, Einat

2013-01-01

Purpose: Congenital portosystemic shunts (CPSS) with portal venous hypoplasia cause hyperammonemia. Acute shunt closure results in portal hypertension. A transcatheter method of staged shunt reduction to afford growth of portal vessels followed by shunt closure is reported. Methods: Pressure measurements and angiography in the CPSS or superior mesenteric artery (SMA) during temporary occlusion of the shunt were performed. If vessels were diminutive and the pressure was above 18 mmHg, a staged approach was performed, which included implantation of a tailored reducing stent to reduce shunt diameter by ∼50 %. Recatheterization was performed approximately 3 months later. If the portal pressure was below 18 mmHg and vessels had developed, the shunt was closed with a device. Results: Six patients (5 boys, 1 girl) with a median age of 3.3 (range 0.5–13) years had CPSS portal venous hypoplasia and hyperammonemia. Five patients underwent staged closure. One patient tolerated acute closure. One patient required surgical shunt banding because a reducing stent could not be positioned. At median follow-up of 3.8 (range 2.2–8.4) years, a total of 21 procedures (20 transcatheter, 1 surgical) were performed. In all patients, the shunt was closed with a significant reduction in portal pressure (27.7 ± 11.3 to 10.8 ± 1.8 mmHg; p = 0.016), significant growth of the portal vessels (0.8 ± 0.5 to 4.0 ± 2.4 mm; p = 0.037), and normalization of ammonia levels (202.1 ± 53.6 to 65.7 ± 9.6 μmol/L; p = 0.002) with no complications. Conclusion: Staged CPSS closure is effective in causing portal vessel growth and treating hyperammonemia

Reproducibility of right-to-left shunt quantification using transthoracic contrast echocardiography in hereditary haemorrhagic telangiectasia.

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Vorselaars, V M M; Velthuis, S; Huitema, M P; Hosman, A E; Westermann, C J J; Snijder, R J; Mager, J J; Post, M C

2018-04-01

Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia. Shunt quantification is used to find treatable PAVMs. So far, there has been no study investigating the reproducibility of this diagnostic test. Therefore, this study aimed to describe inter-observer and inter-injection variability of TTCE. We conducted a prospective single centre study. We included all consecutive persons screened for presence of PAVMs in association with hereditary haemorrhagic telangiectasia in 2015. The videos of two contrast injections per patient were divided and reviewed by two cardiologists blinded for patient data. Pulmonary right-to-left shunts were graded using a three-grade scale. Inter-observer and inter-injection agreement was calculated with κ statistics for the presence and grade of pulmonary right-to-left shunts. We included 107 persons (accounting for 214 injections) (49.5% male, mean age 45.0 ± 16.6 years). A pulmonary right-to-left shunt was present in 136 (63.6%) and 131 (61.2%) injections for observer 1 and 2, respectively. Inter-injection agreement for the presence of pulmonary right-to-left shunts was 0.96 (95% confidence interval (CI) 0.9-1.0) and 0.98 (95% CI 0.94-1.00) for observer 1 and 2, respectively. Inter-injection agreement for pulmonary right-to-left shunt grade was 0.96 (95% CI 0.93-0.99) and 0.95 (95% CI 0.92-0.98) respectively. There was disagreement in right-to-left shunt grade between the contrast injections in 11 patients (10.3%). Inter-observer variability for presence and grade of the pulmonary right-to-left shunt was 0.95 (95% CI 0.91-0.99) and 0.97 (95% CI 0.95-0.99) respectively. TTCE has an excellent inter-injection and inter-observer agreement for both the presence and grade of pulmonary right-to-left shunts.

Pediatric hydrocephalus: 40-year outcomes in 128 hydrocephalic patients treated with shunts during childhood. Assessment of surgical outcome, work participation, and health-related quality of life.

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Paulsen, Anne Henriette; Lundar, Tryggve; Lindegaard, Karl-Fredrik

2015-12-01

Treatment for hydrocephalus has not advanced appreciably since the advent of CSF shunts more than 50 years ago. The outcome for pediatric patients with hydrocephalus has been the object for several studies; however, much uncertainty remains regarding the very long term outcome for these patients. Shunting became the standard treatment for hydrocephalus in Norway during the 1960s, and the first cohorts from this era have now reached middle age. Therefore, the objective of this study was to review surgical outcome, mortality, social outcome, and health-related quality of life in middle-aged patients treated for hydrocephalus during childhood. Data were collected in all patients, age 14 years or less, who required a CSF shunt during the years 1967-1970. Descriptive statistics were assessed regarding patient characteristics, surgical features, social functioning, and work participation. The time and cause of death, if applicable, were also determined. Kaplan-Meier survival estimates were used to determine the overall survival of patients. Information regarding self-perceived health and functional status was assessed using the 36-Item Short Form Health Survey (SF-36) and the Barthel Index score. A total of 128 patients were included in the study, with no patient lost to follow-up. Of the 128 patients in the study, 61 (47.6%) patients died during the 42-45 years of observation. The patients who died belonged to the tumor group (22 patients) and the myelomeningocele group (13 patients). The mortality rate was lowered to 39% if the patients with tumors were excluded. The overall mortality rates at 1, 2, 10, 20, and 40 years from time of initial shunt insertion were 16%, 24%, 31%, 40%, and 48% respectively. The incidence of shunt-related mortality was 8%. The majority of children graduated from a normal school (67%) or from a school specializing in education for physically handicapped children (20%). Self-perceived health was significantly poorer in 6 out of 8 domains

Four-dimensional computed tomography angiographic evaluation of cranial dural arteriovenous fistula before and after embolization.

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Tian, Bing; Xu, Bing; Lu, Jianping; Liu, Qi; Wang, Li; Wang, Minjie

2015-06-01

This study aimed to evaluate the usefulness of four-dimensional CTA before and after embolization treatment with ONYX-18 in eleven patients with cranial dural arteriovenous fistulas, and to compare the results with those of the reference standard DSA. Eleven patients with cranial dural arteriovenous fistulas detected on DSA underwent transarterial embolization with ONYX-18. Four-dimensional CTA was performed an average of 2 days before and 4 days after DSA. Four-dimensional CTA and DSA images were reviewed by two neuroradiologists for identification of feeding arteries and drainage veins and for determining treatment effects. Interobserver and intermodality agreement between four-dimensional CTA and DSA were assessed. Forty-two feeding arteries were identified for 14 fistulas in the 11 patients. Of these, 36 (85.71%) were detected on four-dimensional CTA. After transarterial embolization, one patient got partly embolized, and the fistulas in the remaining 10 patients were completely occluded. The interobserver agreement for four-dimensional CTA and intermodality agreement between four-dimensional CTA and DSA were excellent (κ=1) for shunt location, identification of drainage veins, and fistula occlusion after treatment. Four-dimensional CTA images are highly accurate when compared with DSA images both before and after transarterial embolization treatment. Four-dimensional CTA can be used for diagnosis as well as follow-up of cranial dural arteriovenous fistulas in clinical settings. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Interventional treatment of upper gastrointestinal bleeding in patients of hepatic carcinoma accompanied with hepatic artery-portal vein shunting

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Li Jijun; Shang Jianqiang; Liu Zuoqin; Tang Jun; Sun Zengtao; Chen Jie; Zhang Lei; Liu Hongjun; Zhou Zhaohai

2011-01-01

Objective: To explore the diagnostic and therapeutic efficacy of interventional procedure for upper gastrointestinal bleeding in patients of hepatic carcinoma accompanied with hepatic artery-portal vein shunting (HAPVS). Methods: Clinical data of 27 patients of hepatic carcinoma accompanied with HAPVS were retrospectively analyzed. All patients underwent hepatic arterial angiography and transcatheter arterial embolization. Shunts were embolized with coils, Gelfoam particles or PVA particles. Results: Of 27 patients with upper gastrointestinal bleeding, central type HAPVS was seen in 16 and peripheral type HAPVS in 11. Reversed portal venous flow was detected in 20 cases and ascites was found in 23 cases. The abnormal shunts were successfully occluded in all patients and the bleeding ceased within 2 days after embolization. No recurrent bleeding occurred in one month after the treatment. Ascites disappeared in 16 cases and subsided in 7 cases. Conclusion: HAPVS is an important cause for upper gastrointestinal bleeding in patients of hepatic carcinoma, and the arteriovenous fistula can be confirmed with hepatic artery DSA. Embolization of fistulous orifice is the most effective therapy for such patients. (authors)

Cerebrospinal fluid (CSF) shunting and ventriculocisternostomy (ETV) in 400 pediatric patients. Shifts in understanding, diagnostics, case-mix, and surgical management during half a century.

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Paulsen, A Henriette; Due-Tønnessen, Bernt J; Lundar, Tryggve; Lindegaard, Karl-Fredrik

2017-02-01

To characterize shifts from the 1960s to the first decade in the 21st century as to diagnostics, case-mix, and surgical management of pediatric patients undergoing permanent CSF diversion procedures. One hundred and thirty-four patients below 15 years of age were the first time treated with CSF shunt or ETV for hydrocephalus or idiopathic intracranial hypertension (IIH) in 2009-2013. This represents our current practice. Our previously reported cohorts of shunted children 1967-1970 (n = 128) and 1985-1988 (n = 138) served as backgrounds for comparison. In the 1960s, ventriculography and head circumference measurements were the main diagnostic tools; ventriculoatrial shunt was the preferred procedure (94 %), neural tube defect (NTD) was the leading etiology (33 %), and overall 2-year survival rate was 76 % (non-tumor survival 84 %). In the 1980s, computerized tomography (CT) was the preferred diagnostic imaging tool; ventriculoperitoneal shunt (VPS) had become standard (91 %), the proportion of NTD children declined to 17 %, and the 2-year survival rate was 91 % (non-tumor survival 95 %). Hydrocephalus caused by intracranial hemorrhage had, on the other hand, increased from 7 to 19 %. In the years 2009-2013, when MRI and endoscopic third ventriculocisternostomy (ETV) were matured technologies, 73 % underwent VPS, and 23 % ETV as their initial surgical procedure. The most prevalent etiology was CNS tumor (31 %). The proportion of NTD patients was yet again halved to 8 %, while intracranial hemorrhage was also reduced to 12 %. In this last period, six children were treated with VPS for Idiopathic Intracranial Hypertension (IIH) due to unsatisfactory response to medical treatment. They all had headache, papilledema, and visual disturbances and responded favorably to treatment. The 2 years of survival was 92 % (non-tumor survival 99 %). In contrast to the previous periods, there was no early shunt related mortality (2 years). Aqueductal stenosis

How I do it: surgical ligation of craniocervical junction dural AV fistulas.

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Sorenson, Thomas J; La Pira, Biagia; Hughes, Joshua; Lanzino, Giuseppe

2017-08-01

Dural arteriovenous fistulas (DAVFs) of the craniocervical junction are uncommon vascular lesions, which often require surgical treatment even in the endovascular era. Most commonly, the fistula is placed laterally, and surgical ligation is performed through a lateral suboccipital craniotomy. After dural opening, the area is inspected, and the arterialized vein is identified emerging from the dura, often adjacent to the entry point of the vertebral artery, and ligated. A far lateral craniotomy is the authors' preferred surgical approach for accessing and treating dural arteriovenous fistulas of the craniocervical junction that cannot be reached endovascularly.

Pulmonary arteriovenous malformation in cryptogenic liver

International Nuclear Information System (INIS)

Afzal, N.

2013-01-01

The cause in 10 - 20% cases of liver cirrhosis (LC) cannot be elucidated, and are thus termed cryptogenic. Pulmonary arteriovenous malformations (PAVMs) are relatively rare, but the most common anomaly involving the pulmonary tree. Although the rare correlation between LC and PAVM is well-known, there have been no reports of PAVMs occurring in cryptogenic LC. We report a case of PAVM that occurred in cryptogenic liver cirrhosis in a 3 years old male child. The child presented with complaints of malena, hematemesis and variceal bleed. The examination revealed a child with respiratory distress, irritability, tachycardia, clubbing and abdominal distention. He was worked up for recurrent variceal bleeding secondary to portal hypertension but the oxygen saturation during hospital stay kept deteriorating. The diagnosis of hepatopulmonary syndrome as the cause of persistent hypoxemia in the absence of other cardio-pulmonary causes was then made by enhanced echocardiogram using agitated saline. He improved significantly after liver transplantation performed abroad. At a 6 months follow-up, the child was stable with no evidence of intrapulmonary shunting on repeat echo. (author)

Acquired arteriovenous fistula in a grizzly bear (Ursus arctos horribilis).

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Tuttle, Allison D; MacLean, Robert A; Linder, Keith; Cullen, John M; Wolfe, Barbara A; Loomis, Michael

2009-03-01

A captive adult male grizzly bear (Ursus arctos horribilis) was evaluated due to multifocal wounds of the skin and subcutaneous tissues sustained as a result of trauma from another grizzly bear. On presentation, one lesion that was located in the perineal region seemed to be a deep puncture with purple tissue protruding from it. This perineal wound did not heal in the same manner or rate as did the other wounds. Twenty-five days after initial detection, substantial active hemorrhage from the lesion occurred and necessitated anesthesia for examination of the bear. The entire lesion was surgically excised, which later proved curative. An acquired arteriovenous fistula was diagnosed via histopathology. Arteriovenous fistulas can develop after traumatic injury and should be considered as a potential complication in bears with nonhealing wounds.

Haematology and coagulation profiles in cats with congenital portosystemic shunts.

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Tzounos, Caitlin E; Tivers, Michael S; Adamantos, Sophie E; English, Kate; Rees, Alan L; Lipscomb, Vicky J

2017-12-01

Objectives The objectives of this study were, first, to report the haematological parameters and coagulation times for cats with a congenital portosystemic shunt (CPSS) and the influence of surgical shunt attenuation on these parameters; and, second, to identify any association between prolongation in coagulation profiles and incidence of perioperative haemorrhage. Methods This was a retrospective clinical study using client-owned cats with a CPSS. Signalment, shunt type (extra- or intrahepatic), degree of shunt attenuation (complete or partial), haematological parameters, prothrombin time (PT) and activated partial thromboplastin time (aPTT) test results, and occurrence of any perioperative clinical bleeding complications were recorded for cats undergoing surgical treatment of a CPSS at the Royal Veterinary College, UK, between 1994 and 2011. Results Forty-two cats were included. Thirty-six (85.7%) had an extrahepatic CPSS and six (14.3%) had an intrahepatic CPSS. Preoperatively, mean cell volume (MCV) and mean cell haemoglobin (MCH) were below the reference interval (RI) in 32 (76.2%) and 31 (73.8%) cats, respectively. Red blood cell count and mean cell haemoglobin concentration (MCHC) were above the RI in 10 (23.8%) and eight (19.1%) cats, respectively. Postoperatively, there were significant increases in haematocrit ( P = 0.044), MCV ( P = 0.008) and MCH ( P = 0.002). Despite the significant increase in MCV postoperatively, the median MCV postoperatively was below the RI, indicating persistence of microcytosis. Preoperatively, PT was above the upper RI in 14 cats (87.5%), and aPTT was above the upper RI in 11 cats (68.8%). No cat demonstrated a perioperative clinical bleeding complication. Conclusions and relevance Cats with a CPSS are likely to present with a microcytosis, but rarely present with anaemia, leukocytosis or thrombocytopenia. Surgical attenuation of the CPSS results in a significant increase in the HCT and MCV. Coagulation profiles in cats with a

A large pulmonary arteriovenous malformation causing cerebrovascular accidents.

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Sladden, David; Casha, Aaron; Azzopardi, Conrad; Manche', Alexander

2015-04-16

The incidence of pulmonary arteriovenous malformations (PAVMs) is 2.5 in 100,000. 80% are associated with Osler-Weber-Rendu syndrome or hereditary haemorrhagic telangiectasia. We report the case of a 70-year-old man with a 6 cm spherical mass incidentally found on chest X-ray. There was a localised systolic bruit over the right lower zone posteriorly; however, he was asymptomatic. He had suffered a stroke, affecting his right hand and his speech, from which he recovered. He experienced regular transient ischaemic attacks, on an average of every 2 months. He underwent a right lower lobectomy and on ligating the right lower lobe pulmonary artery the saturations of oxygen rose from 92% to 97%, demonstrating a significant right to left extracardiac shunt. Postoperative recovery was excellent and 1 year later the patient reports no further neurological symptoms. 40% of such lesions exhibit symptoms, however, only one-third are neurological. Treatment should be by percutaneous embolisation. 2015 BMJ Publishing Group Ltd.

Linear accelerator radiosurgery for arteriovenous malformations: Updated literature review.

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Yahya, S; Heyes, G; Nightingale, P; Lamin, S; Chavda, S; Geh, I; Spooner, D; Cruickshank, G; Sanghera, P

2017-04-01

Arteriovenous malformations (AVMs) are the leading causing of intra-cerebral haemorrhage. Stereotactic radiosurgery (SRS) is an established treatment for arteriovenous malformations (AVM) and commonly delivered using Gamma Knife within dedicated radiosurgery units. Linear accelerator (LINAC) SRS is increasingly available however debate remains over whether it offers an equivalent outcome. The aim of this project is to evaluate the outcomes using LINAC SRS for AVMs used within a UK neurosciences unit and review the literature to aid decision making across various SRS platforms. Results have shown comparability across platforms and strongly supports that an adapted LINAC based SRS facility within a dynamic regional neuro-oncology department delivers similar outcomes (in terms of obliteration and toxicity) to any other dedicated radio-surgical platform. Locally available facilities can facilitate discussion between options however throughput will inevitably be lower than centrally based dedicated national radiosurgery units. Copyright © 2016. Published by Elsevier Ltd.

Barry shunt for treatment of a 76-hour stuttering priapism without subsequent erectile dysfunction

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Osmonov DK

2014-07-01

Full Text Available Daniar Kurmanbekovich Osmonov, Aleksey Aksenov, Andrea Nathaly Guerra Sandoval, Almut Kalz, Klaus Peter Juenemann Department of Urology and Pediatric Urology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany Introduction: This paper reports treatment of a 76-hour low-flow priapism with a shunting procedure that was first described by Barry in 1976. We were able to observe the preservation of erectile function despite the long period of ischemia. A review of the literature shows that there are few reports of erectile function recovery after a priapism of similar duration. Materials and methods: A 42-year-old patient presented with a 76-hour priapism, probably caused by consumption of alcohol and illegal drugs. A Barry Shunt procedure was performed. The erectile function of the patient was assessed by means of International Index of Erectile Function score over a follow-up period of 30 months. Moreover, we reviewed different surgical options for treatment of priapism in the literature. Results: Partial return of erection without sexual arousal occurred on two occasions during the 10-day hospitalization, but was treated by manipulation of the penis, ie, by milking the tumescence into the shunt. After 3 months, the shunt was still palpable as a subcutaneous swelling. Six months postoperatively, the residual swelling had disappeared. The International Index of Erectile Function score was of 21 without phosphodiesterase type 5 inhibitors after a follow-up of 2.5 years. Conclusion: Barry shunt is an effective alternative surgical option for the treatment of low-flow priapism. In the case of our patient, it was also effective after a 76-hour-lasting priapism. Keywords: low flow priapism, erectile function, cavernovenous shunt, surgical treatment of stuttering priapism

Delayed angiography in the investigation of intracerebral hematomas caused by small arteriovenous malformations

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Willinsky, R.A. (Dept. of Radiology, Toronto Hospital, Western Div., Toronto, ON (Canada) Univ. of Toronto, Brain Vascular Malformation Study Group, ON (Canada)); Fitzgerald, M. (Dept. of Radiology, Toronto Hospital, Western Div., Toronto, ON (Canada)); TerBrugge, K. (Dept. of Radiology, Toronto Hospital, Western Div., Toronto, ON (Canada) Univ. of Toronto, Brain Vascular Malformation Study Group, ON (Canada)); Montanera, W. (Dept. of Radiology, Toronto Hospital, Western Div., Toronto, ON (Canada)); Wallace, M. (Div. of Neurosurgery, Dept. of Surgery, Toronto Hospital, Western Div., ON (Canada) Univ. of Toronto, Brain Vascular Malformation Study Group, ON (Canada))

1993-04-01

We reviewed the clinical and radiological features of ten patients with small arteriovenous malformations that caused intracerebral hematomas. In six patients, angiography showed a small nidus (less than 1 cm in diameter) with a shunt at the site of the hematoma, and in four only an early-filling vein was evident. Six patients had only delayed angiography (4 weeks or more after the ictus). In three, angiography within 2 days of the ictus failed to reveal the cause of the bleed, but repeat angiography showed an early-filling vein in two, and a nidus with shunting in one. In only one patient did early angiography reveal the malformation. MRI was obtained in eight patients, and in two prominent vessels were evident in the wall of the hematoma cavity. In investigation of an unexplained intracerebral hematoma, MRI may be useful to exclude a neoplasm or cavernoma, although the latter may be not be evident in the presence of a recent hematoma. We suggest early MRI and angiography for investigation of an unexplained, nonhypertensive intracerebral bleed, with follow-up MRI and dealyed angiography if the initial studies fail to reveal the cause. (orig.)

Cerebral arterio-venous malformations at Edgardo Rebagliati Martins Nacional Hospital

OpenAIRE

Rabanal, Jorge

2014-01-01

A review of 50 cases with cerebral arterio.venous malformations (AVM) treated since Junly 1988 through December 1992 in the Neurosurgery Service from Edgardo Rebagliati Martins National Hospital was done. Clinical records, surgical techniques and pre- and post-operative studies were evaluted by retrospective analysis. The more important results were the frecuency of presentations in male patients from the coast, the clinical onset with intracraneal hemorrhage, the operative technique of drain...

Predictors of shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage: a pilot study in a single Egyptian institute.

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Aboul-Ela, Hashem M; Salah El-Din, Ahmed M; Zaater, Ahmed A; Shehab, Mohamed; El Shahawy, Ossama A

2018-01-01

Acute hydrocephalus can cause neurological deterioration after aneurysmal subarachnoid hemorrhage (aSAH). Predicting which patient would require shunting is challenging. This prospective study was conducted upon twenty patients who suffered acute hydrocephalus due to subarachnoid hemorrhage of ruptured aneurysms. Surgical or non-surgical management of hydrocephalus was conducted. Glasgow Coma scale (GCS) was assessed, and hydrocephalus was graded by bicaudate index. Fisher grade was determined from CT scan. Aneurysm site was determined by conventional or CT angiography. Either surgical clipping or endovascular coiling of aneurysms was performed. Initially, 3 (15%) patients had emergency CSF diversion on admission due to poor GCS on arrival. Initially, the remaining 17 patients were managed conservatively. Five patients did not require any intervention. Twelve patients had external ventricular drainage placement, 4 were weaned, and 8 failed weaning. High bicaudate index (> 0.2) correlated with shunting. Aneurysm site correlated well with shunting (ACoA or PCoA). Patients with fair GCS can be managed conservatively. Any deterioration warrants shifting to CSF diversion. Higher bicaudate index will usually need CSF diversion. The value of Fisher carries no significant value. Aneurysm location (ACoA or PCoA) correlates with an increased incidence of ventriculoperitoneal shunt placement.

Stereotactic radiosurgery for deep intracranial arteriovenous malformations, part 1: Brainstem arteriovenous malformations.

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Cohen-Inbar, Or; Ding, Dale; Chen, Ching-Jen; Sheehan, Jason P

2016-02-01

The management of brainstem arteriovenous malformations (AVM) are one of the greatest challenges encountered by neurosurgeons. Brainstem AVM have a higher risk of hemorrhage compared to AVM in other locations, and rupture of these lesions commonly results in devastating neurological morbidity and mortality. The potential morbidity associated with currently available treatment modalities further compounds the complexity of decision making for affected patients. Stereotactic radiosurgery (SRS) has an important role in the management of brainstem AVM. SRS offers acceptable obliteration rates with lower risks of hemorrhage occurring during the latency period. Complex nidal architecture requires a multi-disciplinary treatment approach. Nidi partly involving subpial/epipial regions of the dorsal midbrain or cerebellopontine angle should be considered for a combination of endovascular embolization, micro-surgical resection and SRS. Considering the fact that incompletely obliterated lesions (even when reduced in size) could still cause lethal hemorrhages, additional treatment, including repeat SRS and surgical resection should be considered when complete obliteration is not achieved by first SRS. Patients with brainstem AVM require continued clinical and radiological observation and follow-up after SRS, well after angiographic obliteration has been confirmed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fanconi anaemia with bilateral diffuse pulmonary arterio venous fistulae: a case report

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Samarakoon Lasitha

2012-03-01

Full Text Available Abstract Background We report a patient with cytogenetically confirmed Fanconi anaemia with associated diffuse bilateral pulmonary arterio-venous fistulae. This is only the second reported case of diffuse pulmonary arterio-venous fistulae with Fanconi anaemia. Case Presentation A 16 year old Sri Lankan boy, with a cytogenetically confirmed Fanconi anaemia was admitted to University Medical Unit, National Hospital of Sri Lanka for further assessment and treatment. Both central and peripheral cyanosis plus clubbing were noted on examination. The peripheral saturation was persistently low on room air and did not improve with supplementary Oxygen. Contrast echocardiography failed to demonstrate an intra cardiac shunt but showed early crossover of contrast, suggesting the possibility of pulmonary arterio-venous fistulae. Computed tomography pulmonary angiogram was inconclusive. Subsequent right heart catheterisation revealed bilateral diffuse arterio-venous fistulae not amenable for device closure or surgical intervention. Conclusion To our knowledge, this is the second reported patient with diffuse pulmonary arterio-venous fistulae associated with Fanconi anaemia. We report this case to create awareness among clinicians regarding this elusive association. We recommend screening patients with Fanconi anaemia using contrast echocardiography at the time of assessment with transthoracic echocardiogram. Though universal screening may be impossible given the cost constraints, such screening should at least be performed in patients with clinical evidence of desaturation or when a therapeutic option such as haematopoietic stem cell transplantation is considered. Treatment of pulmonary arteriovenous fistulae would improve patient outcome as desaturation by shunting worsens the anaemic symptoms by reducing the oxygen carrying capacity of blood.

Subacute bacterial endocarditis and subsequent shunt nephritis from ventriculoatrial shunting 14 years after shunt implantation

DEFF Research Database (Denmark)

Burström, Gustav; Andresen, Morten; Bartek, Jiri Jr.

2014-01-01

of causing subacute bacterial endocarditis and subsequent shunt nephritis. The patient was successfully treated with antibiotics combined with ventriculoatrial shunt removal and endoscopic third ventriculocisternostomy (VCS). This case illustrates the nowadays rare, but potentially severe complication...... of subacute bacterial endocarditis and shunt nephritis. It also exemplifies the VCS as an alternative to implanting foreign shunt systems for CSF diversion....

Non-Imaging Acoustical Properties in Monitoring Arteriovenous Hemodialysis Access. A Review

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Anas Mohd Noor

2015-12-01

Full Text Available The limitations of the gold standard angiography technique in arteriovenous access surveillance have opened a gap for researchers to find the best way to monitor this condition with low-cost, non-invasive and continuous bedside monitoring. The phonoangiography technique has been developed prior to these limits. This measurement and monitoring technique, associated with intelligence signal processing, promises better analysis for early detection of hemodialysis access problems, such as stenosis and thrombosis. Some research groups have shown that the phonoangiography technique could identify as many as 20% of vascular diameter changes and also its frequency characteristics due to hemodialysis access problems. The frequency characteristics of these acoustical signals are presented and discussed in detail to understand the association with the stenosis level, blood flows, sensor locations, fundamental frequency bands of normal and abnormal conditions, and also the spectral energy produced. This promising technique could be used in the near future as a tool for pre-diagnosis of arteriovenous access before any further access correction by surgical techniques is required. This paper provides an extensive review of various arteriovenous access monitoring techniques based on non-imaging acoustical properties.

Validity of administrative database code algorithms to identify vascular access placement, surgical revisions, and secondary patency.

Science.gov (United States)

Al-Jaishi, Ahmed A; Moist, Louise M; Oliver, Matthew J; Nash, Danielle M; Fleet, Jamie L; Garg, Amit X; Lok, Charmaine E

2018-03-01

We assessed the validity of physician billing codes and hospital admission using International Classification of Diseases 10th revision codes to identify vascular access placement, secondary patency, and surgical revisions in administrative data. We included adults (≥18 years) with a vascular access placed between 1 April 2004 and 31 March 2013 at the University Health Network, Toronto. Our reference standard was a prospective vascular access database (VASPRO) that contains information on vascular access type and dates of placement, dates for failure, and any revisions. We used VASPRO to assess the validity of different administrative coding algorithms by calculating the sensitivity, specificity, and positive predictive values of vascular access events. The sensitivity (95% confidence interval) of the best performing algorithm to identify arteriovenous access placement was 86% (83%, 89%) and specificity was 92% (89%, 93%). The corresponding numbers to identify catheter insertion were 84% (82%, 86%) and 84% (80%, 87%), respectively. The sensitivity of the best performing coding algorithm to identify arteriovenous access surgical revisions was 81% (67%, 90%) and specificity was 89% (87%, 90%). The algorithm capturing arteriovenous access placement and catheter insertion had a positive predictive value greater than 90% and arteriovenous access surgical revisions had a positive predictive value of 20%. The duration of arteriovenous access secondary patency was on average 578 (553, 603) days in VASPRO and 555 (530, 580) days in administrative databases. Administrative data algorithms have fair to good operating characteristics to identify vascular access placement and arteriovenous access secondary patency. Low positive predictive values for surgical revisions algorithm suggest that administrative data should only be used to rule out the occurrence of an event.

Bacterial contamination of surgeons' gloves during shunt insertion; a pilot study

DEFF Research Database (Denmark)

Sørensen, Preben; Ejlertsen, Tove; Aaen, Dorte

2008-01-01

antibiotics and double gloving, by surgeons experienced in shunt surgery. Surgical incision, dissection and tunnelling were done. Then the surgeon, the scrub-nurse and, in three cases, the assistant made an imprint of their outer gloves on agar plates. Hereafter, they changed the outer pair of gloves before...... handling the shunt and completing the operation. The plates were cultured for 6 days in both aerobic and anaerobic environment. In all cases the surgeons gloves were contaminated, and in six cases also the nurses' gloves were contaminated, as well as all three assistants. Propionebacterium acnes were...... nurse and assistant were contaminated with micro-organisms less than 15 min after surgery has been commenced and before the shunts were handled. This study offers a feasible, simple and logical explanation of how shunts may become contaminated and infected. A simple measure would be to change the outer...

Pathogenesis of arteriovenous malformations in the absence of endoglin.

Science.gov (United States)

Mahmoud, Marwa; Allinson, Kathleen R; Zhai, Zhenhua; Oakenfull, Rachael; Ghandi, Pranita; Adams, Ralf H; Fruttiger, Marcus; Arthur, Helen M

2010-04-30

Arteriovenous malformations (AVMs) result in anomalous direct blood flow between arteries and veins, bypassing the normal capillary bed. Depending on size and location, AVMs may lead to severe clinical effects including systemic cyanosis (pulmonary AVMs), hemorrhagic stroke (cerebral AVMs) and high output cardiac failure (hepatic AVMs). The factors leading to AVM formation are poorly understood, but patients with the familial disease hereditary hemorrhagic telangiectasia (HHT) develop AVMs at high frequency. As most HHT patients have mutations in ENG (endoglin) or ACVRL1 (activin receptor-like kinase 1), a better understanding of the role of these genes in vascular development is likely to reveal the etiology of AVM formation. Using a mouse with a conditional mutation in the Eng gene, we investigated the sequence of abnormal cellular events occurring during development of an AVM. In the absence of endoglin, subcutaneous Matrigel implants in adult mice were populated by reduced numbers of new blood vessels compared with controls, and resulted in local venous enlargement (venomegaly). To investigate abnormal vascular responses in more detail, we turned to the more readily accessible vasculature of the neonatal retina. Endoglin-deficient retinas exhibited delayed remodeling of the capillary plexus, increased proliferation of endothelial cells and localized AVMs. Muscularization of the resulting arteriovenous shunts appeared to be a secondary response to increased blood flow. AVMs develop when an angiogenic stimulus is combined with endoglin depletion. Moreover, AVM formation appears to result from the combination of delayed vascular remodeling and an inappropriate endothelial cell proliferation response in the absence of endoglin.

Pre-Liver Transplant: Tips Versus Distal Splenorenal Shunt

Directory of Open Access Journals (Sweden)

Thomas W. Faust

1997-01-01

Full Text Available Recurrent variceal bleeding in liver transplant candidates with end-stage liver disease can complicate or even prohibit a subsequent transplant procedure (OLT. Endoscopic sclero-therapy and medical therapy are considered as first-line management with surgical shunts reserved for refractory situations. Surgical shunts can be associated with a high mortality in this population and may complicate subsequent OLT. The transjugular intrahepatic portosystemic shunt (TIPS has been recommended in these patients as a bridge to OLT. This is a new modality that has not been compared with previously established therapies such as the distal splenorenal shunt (DSRS. In this study we report our experience with 35 liver transplant recipients who had a previous TIPS (18 patients or DSRS (17 patients for variceal bleeding. The TIPS group had a significantly larger proportion of critically ill and Child-Pugh C patients. Mean operating time was more prolonged in the DSRS group (P=0.014 but transfusion requirements were similar. Intraoperative portal vein blood flow measurements averaged 2132±725 ml/min in the TIPS group compared with 1120±351ml/min in the DSRS group (P<0.001. Arterial flows were similar. Mean ICU and hospital stays were similar. There were 3 hospital mortalities in the DSRS group and none in the TIPS group (P=0.1. We conclude that TIPS is a valuable tool in the management of recurrent variceal bleeding prior to liver transplantation. Intra0Perative hemodynamic measurements suggest a theoretical advantage with TIPS. In a group of patients with advanced liver disease we report an outcome that is similar to patients treated with DSRS prior to liver transplantation. The role of TIPS in the treatment of nontransplant candidates remains to be clarified.

Similar degree of intimal hyperplasia in surgically detected stenotic and nonstenotic arteriovenous fistula segments: a preliminary report.

Science.gov (United States)

Duque, Juan C; Tabbara, Marwan; Martinez, Laisel; Paez, Angela; Selman, Guillermo; Salman, Loay H; Velazquez, Omaida C; Vazquez-Padron, Roberto I

2018-04-01

Intimal hyperplasia has been historically associated with improper venous remodeling and stenosis after creation of an arteriovenous fistula. Recently, however, we showed that intimal hyperplasia by itself does not explain the failure of maturation of 2-stage arteriovenous fistulas. We seek to evaluate whether intimal hyperplasia plays a role in the development of focal stenosis of an arteriovenous fistula. This study compares intimal hyperplasia lesions in stenotic and nearby nonstenotic segments collected from the same arteriovenous fistula. Focal areas of stenosis were detected in the operating room in patients (n= 14) undergoing the second-stage vein transposition procedure. The entire vein was inspected, and areas of stenosis were visually located with the aid of manual palpation and hemodynamic changes in the vein peripheral and central to the narrowing. Stenotic and nonstenotic segments were documented by photography before tissue collection (14 tissue pairs). Intimal area and thickness, intima-media thickness, and intima to media area ratio were measured in hematoxylin and eosin stained cross-sections followed by pairwise statistical comparisons. The intimal area in stenotic and nonstenotic segments ranged from 1.25 to 11.61 mm 2 and 1.29 to 5.81 mm 2 , respectively. There was no significant difference between these 2 groups (P=.26). Maximal intimal thickness (P=.22), maximal intima-media thickness (P=.13), and intima to media area ratio (P=.73) were also similar between both types of segments. This preliminary study indicates that postoperative intimal hyperplasia by itself is not associated with the development of focal venous stenosis in 2-stage fistulas. Copyright © 2017 Elsevier Inc. All rights reserved.

Pictorial essay: trans-jugular intra-hepatic porto-systemic shunt (TIPS)

International Nuclear Information System (INIS)

Rao Anuradha, T.N.; Rastogi, H.; Pandey, U.C.

2001-01-01

TIPS is an interventional radiologic method of creating a portosystemic shunt by percutaneous means. It is a relatively new weapon in the armamentarium of the management of portal hypertension with variceal bleeding or intractable ascites. Using needles, angioplasty balloon catheters and expandable metallic stents, a shunt is established directly inside the liver parenchyma connecting a large hepatic vein with a main portal vein branch. Depending on the diameter of the expandable stent used, the created TIPS diverts various amounts of portal blood into the systemic circulation and results in significant portal decompression, cessation of hemorrhage from esophageal varices and resolution of ascites. TIPS is not only an effective and safe alternative to shunt surgery but is life saving in cases of variceal hemorrhage. The use of TIPS seems to be a valid alternative to surgery and has several advantages over either esophageal transection or surgical shunts. TIPS avoids a general anesthetic, laparotomy, and disruption of the hepatic venous system that may adversely affect subsequent hepatic transplantation. TIPS has been performed on patients without interfering with successful transplantation

Early mediastinal seroma secondary to modified Blalock-Taussig shunts - successful management by percutaneous drainage

International Nuclear Information System (INIS)

Connolly, Bairbre L.; Temple, Michael J.; Chait, Peter G.; Restrepo, Ricardo; Adatia, Ian

2003-01-01

Large symptomatic mediastinal seroma following modified-BT shunts, traditionally required revisional thoracotomy. We describe percutaneous image-guided pigtail catheter drainage in the successful treatment of early mediastinal seroma secondary to PTFE Blalock-Taussig shunt, avoiding thoracotomy. A retrospective review of all relevant clinical and imaging records in five patients was performed. All five presented with intermittent stridor, respiratory distress and/or episodic desaturation within 6 weeks of their surgery. In four of five infants, percutaneous drainage was effective and reoperation was avoided. In one of five, rather than urgent surgical evacuation and BT shunt revision, we were able to perform an elective stage-II bidirectional Glenn SVC-RA anastamosis in a stable infant. There were no complications. Percutaneous image-guided drainage of mediastinal seroma secondary to PTFE-BT shunt is a safe, minimally invasive, and effective treatment. This may avoid BT shunt revision. (orig.)

Transdiaphragmatic Approach to Attenuate Porto-Azygos Shunts Inserting in the Thorax.

Science.gov (United States)

Or, Matan; Kitshoff, Adriaan; Devriendt, Nausikaa; De Ridder, Marianne; Quist-Rybachuk, Galena; de Rooster, Hilde

2016-11-01

To describe the surgical technique and document the application of a transdiaphragmatic approach to attenuate porto-azygos shunts inserting in the thoracic section of the azygos vein. Cadaveric study and prospective case series. Canine cadavers (n=6) and client-owned dogs with porto-azygos shunts inserting in the thoracic section of the azygos vein (n=9). In the cadavers, the azygos vein was filled with aqueous latex. Landmarks were established for creating a safe transdiaphragmatic approach to the caudal intrathoracic portion of the azygos vein. In the clinical cases, porto-azygos communication was diagnosed by trans-splenic portal scintigraphy. All shunts were attenuated close to their insertion site via ventral midline celiotomy and a transdiaphragmatic approach to the shunt. Perioperative complications were recorded. A 3-5 cm incision, 0.5-1 cm ventral and lateral to the level of the aortic hiatus, was made in the pars lumbalis part of the diaphragm. Stay sutures at both sides of the diaphragmatic incision were placed to open up the incision and a retractor was used to push the esophagus away from the aorta. Intrathoracic insertion of the shunt was confirmed intraoperative. Exposure of the shunt insertion site at the azygos vein was excellent in all clinical cases. No intraoperative or postoperative complications were encountered. If thoracic attenuation of a porto-azygos shunt is considered, a transdiaphragmatic approach exposes the insertion site for shunt attenuation. This approach is straightforward, without unnecessary abdominal organ manipulation, and since attenuates at the insertion, avoids missing additional contributing branches. © Copyright 2016 by The American College of Veterinary Surgeons.

Reversibility of hyperintense globus pallidus on T 1-weighted MRI following surgery for a portosystemic shunt in an 8-year-old girl

International Nuclear Information System (INIS)

Ikeda, Shinji; Sera, Yoshihisa; Yoshida, Mituhiro; Ohshiro, Hajime; Uchino, Shinichiro; Seguchi, Sasa; Endo, Fumio

1999-01-01

An 8-year-old Japanese girl with a portosystemic shunt had shown hyperammonaemia since she was 3 years of age. MRI of her brain showed bilateral hyperintense globus pallidus. A portosystemic shunt was evident on US and angiography. She underwent surgical banding of the shunt, after which the lesion and clinical symptoms disappeared. (orig.)

False traumatic aneurysms and arteriovenous fistulas: retrospective analysis.

Science.gov (United States)

Davidovic, Lazar B; Banzić, Igor; Rich, Norman; Dragaš, Marko; Cvetkovic, Slobodan D; Dimic, Andrija

2011-06-01

The purpose of this study was to analyze the incidence, clinical presentation, diagnosis, and treatment of false traumatic aneurysms and arteriovenous fistulas as well as the outcomes of the patients. A retrospective, 16-year survey has been conducted regarding the cases of patients who underwent surgery for false traumatic aneurysms (FTA) of arteries and traumatic arteriovenous fistulas (TAVF). Patients with iatrogenic AV fistulas and iatrogenic false aneurysms were excluded from the study. There were 36 patients with TAVF and 47 with FTA. In all, 73 (87.95%) were male, and 10 (12.05%) were female, with an average age of 36.93 years (13-82 years). In 25 (29.76%) cases TAVF and FTA appeared combat-related, and 59 (70.24%) were in noncombatants. The average of all intervals between the injury and surgery was 919. 8 days (1 day to 41 years) for FTA and 396.6 days (1 day to 9 years) for TAVF. Most of the patients in both groups were surgically treated during the first 30 days after injury. One patient died on the fourth postoperative day. There were two early complications. The early patency rate was 83.34%, and limb salvage was 100%. There were no recurrent AV fistulas that required additional operations. Because of their history of severe complications, FTA and TAV fistulas require prompt treatment. The treatment is simpler if there is only a short interval between the injury and the operation. Surgical endovascular repair is mostly indicated.

The transjugular portosystemic stent shunt (TIPSS) as an intervention in clinical complication of portal hypertension

International Nuclear Information System (INIS)

Thalhammer, A.; Jacobi, V.; Schwarz, W.; Balzer, J.; Abolmaali, N.; Vogl, T.J.

2001-01-01

Most frequent complications in patients with liver cirrhosis are due to portal hypertension. Beside ascites circumvent vessles formate with vasodilatation. Due to counterregulation a secondary hyperaldosteronism develops with release of vasocontrictive agents. If conservative and endoscopic methods fail, indication for building a portosystemic shunt is given. The TIPSS procedure is less invasive than the surgical method of Warren-Shunt, so the radiological intervention has replaced surgery. Reducing the portal pressure by the shunt, the clinical complications change for the better. Still problems are defined as hepatic encephalopathy and right ventricular heart failure. Regular follow up investigations have to be performed to detect complications in the shunt. Using regular clinical and radiological check up TIPSS is of clinical benefit with good long term results. (orig.) [de

Traumatic subclavian arteriovenous fistula in a young adult

International Nuclear Information System (INIS)

Nazario Dolz, Ana Maria; Ibannez Casero, Marlene; Rodriguez Fernandez, Zenen; Pichin Quesada, Alexis; Lopez Martin, Jose Carlos

2011-01-01

The case report of a 23 year-old patient who was admitted to the General Surgery Service of 'Saturnino Lora Torres' Provincial Teaching Clinical Surgical Hospital in Santiago de Cuba with the diagnosis of traumatic pneumothorax is described, as consequence of stab wounds in the right anterior and superior region of the thorax; but then, after 48 hours, a right subclavian arteriovenous fistula, which was proven by means of x ray was diagnosed. The postoperative clinical course was favorable and the patient was discharged after 11 days, completely asymptomatic. His working activities began 2 months later.(author)

Scrotal migration of ventriculoperitoneal shunt: a case report at Haji Adam Malik hospital, Medan

Science.gov (United States)

Dharmajaya, R.

2018-03-01

Ventriculoperitoneal (VP) shunting is one of the most common pediatric neurosurgery operations performed for dealing with hydrocephalus. We report an unusual case of a 1-year-old child with communicating hydrocephalus, who experienced right scrotum swelling after 11 months of shunting. Abdominal x-ray showed the shunt tubing, which was kinked in its distal portion of thescrotum. Ultrasound examination was performed, revealing hydrocele along with the presence of thedistal catheter in the scrotum. The patient underwent distal catheter trimming via laparoscopic approach with general surgery and managed with asuccessful outcome. Prompt surgical management of catheter repositioning is recommended to avoid the risk of further complications.

The contribution of intrapulmonary shunts to the alveolar-to-arterial oxygen difference during exercise is very small

DEFF Research Database (Denmark)

Vogiatzis, Ioannis; Zakynthinos, Spyros; Boushel, Robert

2008-01-01

Exercise is well known to cause arterial PO2 to fall and the alveolar-arterial PO2 difference(Aa PO2 ) to increase. Until recently, the physiological basis for this was considered to be mostly ventilation/perfusion ((.)VA/(.)Q) inequality and alveolar-capillary diffusion limitation. Recently......, arterio-venous shunting through dilated pulmonary blood vessels has been proposed to explain a significant part of the Aa PO2 during exercise. To test this hypothesis we determined venous admixture during 5 min of near-maximal, constant-load, exercise in hypoxia (in inspired O2 fraction, FIO2 , 0...... venous admixture, Aa PO2 and hypoxaemia during heavy exercise....

Ventriculoperitoneal Shunt Migration

Directory of Open Access Journals (Sweden)

Justin P Puller

2017-01-01

Full Text Available History of present illness: A 40-year-old female presented to our ED with left upper abdominal pain and flank pain. The pain had begun suddenly 2 hours prior when she was reaching into a freezer to get a bag of frozen vegetables. She described the pain as sharp, constant, severe, and worse with movements and breathing. The pain radiated to the left shoulder. On review of systems, the patient had mild dyspnea and nausea. She denied fever, chills, headache, vision changes, vomiting, or urinary symptoms. Her medical history was notable for obstructive sleep apnea, gastroesophageal reflux disease, arthritis, fibromyalgia, depression, obesity, and idiopathic intracranial hypertension. For the latter, she had a VP (ventriculoperitoneal shunt placed 14 years prior to this visit. She had a history of 2 shunt revisions, the most recent 30 days before this ED visit. Significant findings: An immediate post-op abdominal x-ray performed after the patient’s VP shunt revision 30 days prior to this ED visit reveals the VP shunt tip in the mid abdomen. A CT of the abdomen performed on the day of the ED visit reveals the VP shunt tip interposed between the spleen and the diaphragm. Discussion: VP shunts have been reported to migrate to varied locations in the thorax and abdomen. Incidence of abdominal complications of VP shunt placement ranges from 10%-30%, and can include pseudocyst formation, migration, peritonitis, CSF ascites, infection, and viscus perforation. Incidence of distal shunt migration is reported as 10%, and most previously reported cases occurred in pediatric patients.1 A recent retrospective review cited BMI greater than thirty and previous shunt procedure as risk factors for distal shunt migration.2 The patient in the case presented had a BMI of 59 and 3 previous shunt procedures.

Pathophysiology of shunt dysfunction in shunt treated hydrocephalus

DEFF Research Database (Denmark)

Blegvad, C.; Skjolding, A D; Broholm, H

2013-01-01

We hypothesized that shunt dysfunction in the ventricular catheter and the shunt valve is caused by different cellular responses. We also hypothesized that the cellular responses depend on different pathophysiological mechanisms....

Idiopathic intracranial hypertension: lumboperitoneal shunts versus ventriculoperitoneal shunts--case series and literature review.

LENUS (Irish Health Repository)

Abubaker, Khalid

2012-02-01

OBJECTIVES: Idiopathic intracranial hypertension (IIH) is an uncommon but important cause of headache that can lead to visual loss. This study was undertaken to review our experience in the treatment of IIH by neuronavigation-assisted ventriculoperitoneal (VP) shunts with programmable valves as compared to lumboperitoneal (LP) shunts. METHODS: A retrospective chart review was conducted on 25 patients treated for IIH between 2001 and 2009. Age, sex, clinical presentation, methods of treatment and failure rates were recorded. RESULTS: Seventy-two per cent were treated initially with LP shunts. Failure rate was 11% in this group. Neuronavigation-assisted VP shunts were used to treat 28%. In this group, the failure rate was 14%. CONCLUSION: Our experience indicates that both LP shunts and VP shuts are effective in controlling all the clinical manifestations of IIH in the immediate postoperative period. Failure rates are slightly higher for VP shunts (14%) than LP shunts (11%). However, revision rates are higher with LP shunts (60%) than with VP shunts (30%).

Embolotherapy for pulmonary arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)

DEFF Research Database (Denmark)

Andersen, P E; Kjeldsen, A D; Oxhøj, H

1998-01-01

experienced an improved functional level. One patient experienced severe pleurisy and another a rise in temperature following treatment, but otherwise no symptomatic complications were observed. CONCLUSION: Embolotherapy is a definitive treatment for PAVMs: it is very effective with a high success rate......PURPOSE: To evaluate the clinical results of embolization of pulmonary arteriovenous malformations (PAVMs) in patients with hereditary hemorrhagic telangiectasia (HHT), the Rendu-Osler-Weber syndrome. MATERIAL AND METHODS: Twelve patients in the county of Fyn, Denmark, were treated...... with transcatheter embolization of 20 PAVMs using 12 detachable silicone balloons and 26 steel coils. RESULTS: All PAVMs were completely occluded and we observed a significant rise in PaO2 after treatment and a significant decrease in right-to-left shunt estimated by contrast echocardiography. All patients...

Stereotactic helium-ion radiosurgery for the treatment of intracranial arteriovenous malformations

International Nuclear Information System (INIS)

Fabrikant, J.I.; Levy, R.P.; Frankel, K.A.; Phillips, M.H.; Lyman, J.T.; Chuang, F.Y.S.; Steinberg, G.K.; Marks, M.P.

1989-12-01

One of the more challenging problems of vascular neurosurgery is the management of surgically-inaccessible arteriovenous malformations (AVMs) of the brain. At Lawrence Berkeley Laboratory, we have developed the method of stereotactic heavy-charged-particle (helium-ion) Bragg peak radiosurgery for treatment of inoperable intracranial AVMs in over 300 patients since 1980 [Fabrikant et al. 1989, Fabrikant et al. 1985, Levy et al. 1989]. This report describes patient selection, treatment method, clinical and neuroradiologic results and complications encountered. 4 refs

A tale of two cases of pulmonary arteriovenous malformation: How they fared after cardiac transplantation.

Science.gov (United States)

Wisotzkey, Bethany L; Magyar, Dari L; Jones, Thomas K; Boucek, Robert J; Permut, Lester C; Kemna, Mariska S; Law, Yuk M

2018-02-01

In single ventricle patients, aortopulmonary collaterals (APCs) and pulmonary arteriovenous malformations (PAVMs) following superior cavopulmonary shunt (CPS) can complicate orthotopic heart transplant (OHT) by cyanosis and hemoptysis. Although PAVMs can regress with the restoration of hepatic venous flow to the pulmonary circulation, the effects of hypoxemia on the "unconditioned" allograft are not known. Two patients with significant PAVMs after CPS were cyanotic following OHT. One patient with predominantly unilateral left PAVMs had arterial saturation levels less than 70% despite pulmonary vasodilators and ventilation. A custom flow restrictor-covered stent was deployed in the pulmonary artery of the affected side, redirecting the blood flow to the contralateral lung, immediately improving cyanosis. When the PAVMs regressed, the flow restrictor stent was dilated to eliminate the constriction. The second patient with PAVMs had cyanosis and severe hemoptysis from APCs post-OHT. The APCs required an extensive coil embolization, while the cyanosis responded to oxygen and pulmonary vasodilators. Both recipients did well with gradual resolution of PAVMs within 8 months. Despite cyanosis from right-to-left intrapulmonary shunting, allograft function recovered. Novel transcatheter interventions can play a role in patients with significant APCs or PAVM following cardiac transplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Surgical revascularization induces angiogenesis in orthotopic bone allograft

NARCIS (Netherlands)

Willems, Wouter F.; Kremer, Thomas; Friedrich, Patricia; Bishop, Allen T.

2012-01-01

Remodeling of structural bone allografts relies on adequate revascularization, which can theoretically be induced by surgical revascularization. We developed a new orthotopic animal model to determine the technical feasibility of axial arteriovenous bundle implantation and resultant angiogenesis. We

Risk factors for worsened muscle strength after the surgical treatment of arteriovenous malformations of the eloquent motor area.

Science.gov (United States)

Lin, Fuxin; Zhao, Bing; Wu, Jun; Wang, Lijun; Jin, Zhen; Cao, Yong; Wang, Shuo

2016-08-01

OBJECT Case selection for the surgical treatment of arteriovenous malformations (AVMs) of the eloquent motor area remains challenging. The aim of this study was to determine the risk factors for worsened muscle strength after surgery in patients with this disorder. METHODS At their hospital the authors retrospectively studied 48 consecutive patients with AVMs involving motor cortex and/or the descending pathway. All patients had undergone preoperative functional MRI (fMRI) and diffusion tensor imaging (DTI), followed by resection. Both functional and angioarchitectural factors were analyzed with respect to the change in muscle strength. Functional factors included lesion-to-corticospinal tract distance (LCD) on DTI and lesion-to-activation area distance (LAD) and cortical reorganization on fMRI. Based on preoperative muscle strength, the changes in muscle strength at 1 week and 6 months after surgery were defined as short-term and long-term surgical outcomes, respectively. Statistical analysis was performed using the statistical package SPSS (version 20.0.0, IBM Corp.). RESULTS Twenty-one patients (43.8%) had worsened muscle strength 1 week after surgery. However, only 10 patients (20.8%) suffered from muscle strength worsening 6 months after surgery. The LCD was significantly correlated with short-term (p 0 mm (p = 0.009) and LCD > 5 mm (p 0 mm group and LCD > 5 mm group (p = 0.116). Nidus size was the other significant predictor of short-term (p = 0.021) and long-term (p = 0.016) outcomes. For long-term outcomes, the area under the ROC curve (AUC) was 0.728, and the cutoff point was 3.6 cm. Spetzler-Martin grade was not associated with short-term surgical outcomes (0.143), although it was correlated with long-term outcomes (0.038). CONCLUSIONS An AVM with a nidus in contact with tracked eloquent fibers (LCD = 0) and having a large size is more likely to be associated with worsened muscle strength after surgery in patients with eloquent motor area AVMs. Surgical

External thoracic duct-venous shunt in conscious pigs for long term studies of connective tissue metabolites in lymph

DEFF Research Database (Denmark)

Jensen, L T; Olesen, H P; Risteli, J

1990-01-01

An experimental animal model for lymph studies is described. Thoracic duct-venous shunt was established in 12 pigs. Shunt patency averaged 5.5 days. The composition of connective tissue metabolites in lymph and serum were investigated during a standardized surgical operation (thoracotomy) under...... instead of dogs and sheep in studies on lymph. The effect of surgery/anesthesia must be taken into consideration....

Four-dimensional computed tomography angiographic evaluation of cranial dural arteriovenous fistula before and after embolization

International Nuclear Information System (INIS)

Tian, Bing; Xu, Bing; Lu, Jianping; Liu, Qi; Wang, Li; Wang, Minjie

2015-01-01

Highlights: • 4D CTA showed excellent agreement with DSA with regard to identification of feeding arteries and drainage veins. • The most important finding was 4D CTA in determining the impact of DAVF treatment with transarterial embolization. • 4D CTA provides images similar to those obtained with DSA both before and after treatment. - Abstract: Purpose: This study aimed to evaluate the usefulness of four-dimensional CTA before and after embolization treatment with ONYX-18 in eleven patients with cranial dural arteriovenous fistulas, and to compare the results with those of the reference standard DSA. Patients and Methods: Eleven patients with cranial dural arteriovenous fistulas detected on DSA underwent transarterial embolization with ONYX-18. Four-dimensional CTA was performed an average of 2 days before and 4 days after DSA. Four-dimensional CTA and DSA images were reviewed by two neuroradiologists for identification of feeding arteries and drainage veins and for determining treatment effects. Interobserver and intermodality agreement between four-dimensional CTA and DSA were assessed. Results: Forty-two feeding arteries were identified for 14 fistulas in the 11 patients. Of these, 36 (85.71%) were detected on four-dimensional CTA. After transarterial embolization, one patient got partly embolized, and the fistulas in the remaining 10 patients were completely occluded. The interobserver agreement for four-dimensional CTA and intermodality agreement between four-dimensional CTA and DSA were excellent (κ = 1) for shunt location, identification of drainage veins, and fistula occlusion after treatment. Conclusion: Four-dimensional CTA images are highly accurate when compared with DSA images both before and after transarterial embolization treatment. Four-dimensional CTA can be used for diagnosis as well as follow-up of cranial dural arteriovenous fistulas in clinical settings

Reduction of shunt obstructions by using a peel-away sheath technique? A multicenter prospective randomized trial.

Science.gov (United States)

Kehler, Uwe; Langer, Niels; Gliemroth, Jan; Meier, Ullrich; Lemcke, Johannes; Sprung, Christian; Schlosser, Hans-Georg; Kiefer, Michael; Eymann, Regina; Heese, Oliver

2012-05-01

Shunt obstructions may partly be caused by brain debris, which intrude into the ventricular catheter during ventricle puncture. Avoiding contact between the catheter and brain tissue, by using a peel-away sheath, should reduce the number of shunt failures caused by obstruction. To test this hypothesis, we conducted a randomized, prospective multicenter study. 201 patients from 6 different neurosurgical centers in Germany receiving a ventriculo-peritoneal shunt were included in this study. Of these, 177 patients completed a 1-year follow-up period. Surgery was randomized in a 1 to 1 fashion, such that out of 177 procedures, 91 were performed using a peel-away sheath and 86 were performed without. The rate of surgical re-interventions and shunt obstructions within a 12-month period was recorded. Within 1 year post-surgery, 17 shunt obstructions (9.6%) leading to shunt revisions were recorded. However, no difference was found between surgeries performed using a peel-away sheath (9.9%) or not (9.3%). The overall shunt infection rate was 2.8% and the shunt revision rate for overdrainage was 3.9%. The theoretical advantages attributed to the use of a peel-away sheath to introduce a ventricular catheter could not be confirmed in this randomized study, suggesting that the proposed role of brain debris in shunt obstructions may be overestimated. Copyright © 2011 Elsevier B.V. All rights reserved.

Ventriculo-pleural shunt patency study

International Nuclear Information System (INIS)

Yeates, K.

2000-01-01

Full text: A twenty-four year old male was admitted to hospital complaining of headaches, drowsiness and blurred vision. He suffered from congenital hydrocephalus and had had a ventriculo-peritoneal shunt inserted in infancy. This had undergone many revisions due to persistent peritoneal infections and had recently been replaced with a ventriculo-pleural shunt. The symptoms described suggested shunt blockage and he was referred for a Shunt Patency Study. The current shunt is a HAKIM Programmable Valve Shunt System and the opening pressure was 12cm of CSF (within the normal range). Forty megabecquerels of filtered 99 Tc m O 4 was injected into the pre-chamber of the shunt. Serial images and counts were obtained for twenty-five minutes after the injection. The images showed the tracer flowing from the shunt within the first ten minutes. At twenty minutes almost all of the tracer had drained from the shunt and was present in the right pleural cavity, indicating shunt patency. This study is presented to demonstrate the appearances of a normally functioning, but rarely seen Ventriculo-Pleural CSF Shunt. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

[Results of the mesoportal bypass (Rex shunt) in the treatment of idiopathic extrahepatic portal vein obstruction in children].

Science.gov (United States)

Domínguez Amillo, E; De la Torre Ramos, C; Andrés Moreno, A; Encinas Hernández, J L; Hernández Oliveros, F; López Santamaría, M

2017-01-25

Extrahepatic portal vein obstruction (EPVO) is the principal cause of portal hypertension in children. The objective of this study was to analyze the capacity of the surgical technique that creates a mesoportal shunt to treat changes caused by EPVO. Retrospective review of patients with idiopathic EPVO who underwent a mesoportal shunt and analysis of the changes in the number of leucocytes, platelets, prothrombin time and spleen size one year after the surgery. Twelve patients underwent surgery, out of which 10 had prior leukopenia, 11 thrombopenia, 9 longer prothrombin times and all had hypersplenism. One patient suffered a postoperative shunt thrombosis, was reoperated and underwent a change in the operative technique. The remaining patients (92%) have functioning shunts 4.3 ± 2.5 years after surgery, and none have suffered any episode of gastrointestinal bleeding. One year after surgery, there were significant changes in the number of platelets, prothrombin time and spleen size, with no significant changes in the number of leukocytes. However, the number of patients who went from a leukopenic to a normal state was significant, as happened with changes in prothrombin time. Mesoportal Rex shunt improves some of the disorders caused by portal hypertension in children suffering EPVO, with a high rate of surgical success. This technique should be of first choice in these patients.

Transcatheter Potts shunt creation in patients with severe pulmonary arterial hypertension: initial clinical experience.

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Esch, Jesse J; Shah, Pinak B; Cockrill, Barbara A; Farber, Harrison W; Landzberg, Michael J; Mehra, Mandeep R; Mullen, Mary P; Opotowsky, Alexander R; Waxman, Aaron B; Lock, James E; Marshall, Audrey C

2013-04-01

Patients with severe pulmonary arterial hypertension (PAH) face significant morbidity and death as a consequence of progressive right heart failure. Surgical shunt placement between the left PA and descending aorta (Potts shunt) appears promising for PAH palliation in children; however, surgical mortality is likely to be unacceptably high in adults with PAH. We describe a technique for transcatheter Potts shunt (TPS) creation by fluoroscopically guided retrograde needle perforation of the descending aorta at the site of apposition to the left PA to create a tract for deployment of a covered stent between these vessels. This covered stent-anchored by the vessel walls and surrounding tissue-serves as the shunt. TPS creation was considered in 7 patients and performed in 4. The procedure was technically successful in 3 patients; 1 patient died during the procedure as a result of uncontrolled hemothorax. One acute survivor, critically ill at the time of TPS creation, later died of comorbidities. The 2 mid-term survivors (follow-up of 10 and 4 months) are well at home, with symptomatic improvement and no late complications. The 3 candidate patients in whom the procedure was not performed died within 1 month of consideration, underscoring the tenuous nature of this population. TPS creation is feasible and may offer symptomatic relief to select patients with refractory PAH. Further study of this innovative approach is warranted. Copyright © 2013 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

[Shunt and short circuit].

Science.gov (United States)

Rangel-Abundis, Alberto

2006-01-01

Shunt and short circuit are antonyms. In French, the term shunt has been adopted to denote the alternative pathway of blood flow. However, in French, as well as in Spanish, the word short circuit (court-circuit and cortocircuito) is synonymous with shunt, giving rise to a linguistic and scientific inconsistency. Scientific because shunt and short circuit made reference to a phenomenon that occurs in the field of the physics. Because shunt and short circuit are antonyms, it is necessary to clarify that shunt is an alternative pathway of flow from a net of high resistance to a net of low resistance, maintaining the stream. Short circuit is the interruption of the flow, because a high resistance impeaches the flood. This concept is applied to electrical and cardiovascular physiology, as well as to the metabolic pathways.

Tube shunt complications and their prevention.

Science.gov (United States)

Sarkisian, Steven R

2009-03-01

Glaucoma drainage devices (GDDs) have been generally accepted as a treatment of refractory glaucoma. GDDs have their own unique set of complications that are important to evaluate to prevent them. Tube shunts are typically used in eyes with refractory glaucoma. There is increased interest in studying the efficacy of GDDs. Most of the attention has been focused on comparing trabeculectomy with the Baerveldt implant (Advanced Medical Optics, Inc., Santa Anna, California, USA). The other leading implant is the Ahmed Glaucoma Valve. There are several retrospective studies comparing these two devices and a prospective study is ongoing. There is great interest in the complication rate of tube shunts and these have been published both retrospectively and prospectively. Complications such as hypotony, diplopia, strabismus, proptosis, tube erosion, failure, corneal decompensation, endophthalmitis, and visual loss are all important and some have recently been reviewed in the literature. Moreover, the use of glaucoma drainage implants in the pediatric population has been evaluated. Glaucoma drainage implants have been a powerful tool in our surgical fight to prevent blindness; however, they are not without complications or controversy.

Myocardial blood flow and V/sub O2/ in conscious lambs with an aortopulmonary shunt

International Nuclear Information System (INIS)

Toorop, G.P.; Hardjowijono, R.; Dalinghaus, M.; Gerding, A.M.; Koers, J.H.; Zijlstra, W.G.; Kuipers, J.R.G.

1987-01-01

The authors measured myocardial blood flow (q/sub LVFW/) using radioactively-labeled microspheres and O 2 consumption of the left ventricular free wall (V/sub O 2 , LVFW/) in 13 chronically instrumented, 7-wk-old lambs with an aortopulmonary left-to-right shunt (S) and in 10 control lamps without a shunt (C). The measured V/sub O 2 , LVFW/ was compared with the calculated values obtained by two predictive indexes, the rate-pressure product (RPP) and the pressure-work index (PWI). Measured V/sub O 2 , LVFW/ in S lambs was significantly higher than in C lambs. This was achieved by the significantly higher q/sub LVFW/, since the arteriovenous O 2 difference across the left ventricular free wall was similar in both groups of lambs. Total coronary blood flow per unit body mass in S lambs was higher than in C lambs, not only because of the increased V/sub O 2 , LVFW/ per unit muscle mass, but also because of the increased total heart weight. Correct estimation of V/sub O 2 /, LVFW/ by means of the RPP and the PWI was only possible in C lambs. In S lambs the estimated values were significantly lower than the measured ones. They conclude that since V/sub O 2 , LVFW/ in S lambs is twice as high as in C lambs, the data support the view that a volume load caused by a left-to-right shunt may have a more profound effect on myocardial O 2 consumption than could be anticipated on the basis of previous work

[Mesenteric-cava shunt's results with autologous jugular vein graft in children with pre-sinusoidal portal hypertension].

Science.gov (United States)

Leal, N; López Santamaría, M; Gámez, M; Murcia, J; Andolfi, G; Berrocal, T; Frauca, E; Jara, P; Tovar, J

2002-07-01

Presinusoidal portal hypertension (PPH) in children evaluates without functional hepatic damage, and with the time, trends to compensate through the creation of spontaneous portosystemic shunts. Nevertheless, some patients suffer episodes of gastrointestinal bleeding (GIB) that because of its frequency or severity, force to propose the change of surgical treatment. To evaluate the results of the mesocaval shunt (MCS) with autologous jugular vein in children with PPH. Among the 32 children with PPH treated in our Hospital in the last 7 years, 10 had episodes of GIB that forced to perform a surgical shunt. The types of shunt were distal splenorenal in 3 patients and mesocaval in 7. These 7 cases are the material of this study. The origin of the PPH was a cavernomatosis transformation of the portal vein in 6 cases and a congenital hepatic fibrosis in 1. Before the surgery the average number of episodes of GIB was 9 (range 2-15); all the patients needed transfusion of blood products and variceal sclerosis. In 2 cases a tamponade with the Sengtaken balloon was required and 5 patients were treated with somatostatin and propranolol. The Doppler ultrasounds revealed and intense hepatofugal collateral circulation in all the cases. The initial flow through the shunt was adequate in all the patients except one who required a percutaneous balloon dilatation. Only this patient has suffered an episode of GIB. The hyperesplenism signs disappeared or improved in all the seven cases and the collateral circulation was significantly reduced. The pressure in the splenic territory decreased around 50% in the 4 patients that was measured. There were no cases of encephalopasty and only one child with congenital hepatic fibrosis shows signs of mild hepatic disfunction. The medium follow up post-shunt is 32 months (range 8 m-6 years). The MCS prevents the GIB in the PPH not responsive to the conservative treatment; its effectiveness is related with an adequate permeability though the graft

Our initial experience with ventriculo-epiplooic shunt in treatment of hydrocephalus in two centers.

Science.gov (United States)

Grigorean, Valentin Titus; Sandu, Aurelia Mihaela; Popescu, Mihai; Florian, Ioan Stefan; Lupascu, Cristian Dumitru; Ursulescu, Corina Lupascu

Hydrocephalus represents impairment in cerebrospinal fluid (CSF) dynamics. If the treatment of hydrocephalus is considered difficult, the repeated revisions of ventriculo-peritoneal (VP) shunts are even more challenging. The aim of this article is to evaluate the efficiency of ventriculo-epiplooic (VEp) shunt as a feasible alternative in hydrocephalic patients. A technical modification regarding the insertion of peritoneal catheter was imagined: midline laparotomy 8-10cm long was performed in order to open the peritoneal cavity; the great omentum was dissected between its two layers; we placed the distal end of the catheter between the two epiplooic layers; a fenestration of 4cm in diameter into the visceral layer was also performed. A retrospective study of medical records of 15 consecutive patients with hydrocephalus treated with VEp shunt is also presented. Between 2008 and 2014 we performed VEp shunt in 15 patients: 5 with congenital hydrocephalus, 8 with secondary hydrocephalus and 2 with normal pressure hydrocephalus. There were 7 men and 8 women. VEp shunt was performed in 13 patients with multiple distal shunt failures and in 2 patients, with history of abdominal surgery, as de novo extracranial drainage procedure. The outcome was favorable in all cases, with no significant postoperative complications. VEp shunt is a new, safe and efficient surgical technique for the treatment of hydrocephalus. VEp shunt is indicated in patients with history of recurrent distal shunt failures, and in patients with history of open abdominal surgery and high risk for developing abdominal complications. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Splenorenal shunt via magnetic compression technique: a feasibility study in canine and cadaver.

Science.gov (United States)

Xue, Fei; Li, Jianpeng; Lu, Jianwen; Zhu, Haoyang; Liu, Wenyan; Zhang, Hongke; Yang, Huan; Guo, Hongchang; Lv, Yi

2016-12-01

The concept of magnetic compression technique (MCT) has been accepted by surgeons to solve a variety of surgical problems. In this study, we attempted to explore the feasibility of a splenorenal shunt using MCT in canine and cadaver. The diameters of the splenic vein (SV), the left renal vein (LRV), and the vertical interval between them, were measured in computer tomography (CT) images obtained from 30 patients with portal hypertension and in 20 adult cadavers. The magnetic devices used for the splenorenal shunt were then manufactured based on the anatomic parameters measured above. The observation of the anatomical structure showed there were no special structural tissues or any important organs between SV and LRV. Then the magnetic compression splenorenal shunt procedure was performed in three dogs and five cadavers. Seven days later, the necrotic tissue between the two magnets was shed and the magnets were removed with the anchor wire. The feasibility of splenorenal shunt via MCT was successfully shown in both canine and cadaver, thus providing a theoretical support for future clinical application.

Arteriovenous Malformations

Science.gov (United States)

Arteriovenous malformations (AVMs) are defects in your vascular system. The vascular system includes arteries, veins, and capillaries. Arteries carry blood away from the heart to other organs; veins carry blood back to the heart. Capillaries connect the arteries and veins. An ...

Dural arteriovenous fistula presenting with exophthalmos and seizures.

Science.gov (United States)

Feyissa, Anteneh M; Ponce, Lucido L; Patterson, Joel T; Von Ritschl, Rudiger H; Smith, Robert G

2014-03-15

Concomitant seizures and exophthalmos in the context of a temporal dural arteriovenous fistula (dAVF) has not been described before. Here, we report a 55-year-old-male who presented with an 8-month history of progressive painless exophthalmos of his left eye, conjunctival chemosis, reduced vision and new onset complex partial seizures. Cerebral angiography demonstrated Cognard Type IIa left cerebral dAVF fed by branches from the left occipital artery and an accessory meningeal artery, with drainage to the superior ophthalmic vein. Following surgical obliteration of dAVF feeding vessels, our patient had dramatic improvement in visual acuity, proptosis and chemosis along with cessation of clinical seizures. Published by Elsevier B.V.

Shunting outcomes in posthemorrhagic hydrocephalus: results of a Hydrocephalus Clinical Research Network prospective cohort study.

Science.gov (United States)

Wellons, John C; Shannon, Chevis N; Holubkov, Richard; Riva-Cambrin, Jay; Kulkarni, Abhaya V; Limbrick, David D; Whitehead, William; Browd, Samuel; Rozzelle, Curtis; Simon, Tamara D; Tamber, Mandeep S; Oakes, W Jerry; Drake, James; Luerssen, Thomas G; Kestle, John

2017-07-01

OBJECTIVE Previous Hydrocephalus Clinical Research Network (HCRN) retrospective studies have shown a 15% difference in rates of conversion to permanent shunts with the use of ventriculosubgaleal shunts (VSGSs) versus ventricular reservoirs (VRs) as temporization procedures in the treatment of hydrocephalus due to high-grade intraventricular hemorrhage (IVH) of prematurity. Further research in the same study line revealed a strong influence of center-specific decision-making on shunt outcomes. The primary goal of this prospective study was to standardize decision-making across centers to determine true procedural superiority, if any, of VSGS versus VR as a temporization procedure in high-grade IVH of prematurity. METHODS The HCRN conducted a prospective cohort study across 6 centers with an approximate 1.5- to 3-year accrual period (depending on center) followed by 6 months of follow-up. Infants with premature birth, who weighed less than 1500 g, had Grade 3 or 4 IVH of prematurity, and had more than 72 hours of life expectancy were included in the study. Based on a priori consensus, decisions were standardized regarding the timing of initial surgical treatment, upfront shunt versus temporization procedure (VR or VSGS), and when to convert a VR or VSGS to a permanent shunt. Physical examination assessment and surgical technique were also standardized. The primary outcome was the proportion of infants who underwent conversion to a permanent shunt. The major secondary outcomes of interest included infection and other complication rates. RESULTS One hundred forty-five premature infants were enrolled and met criteria for analysis. Using the standardized decision rubrics, 28 infants never reached the threshold for treatment, 11 initially received permanent shunts, 4 were initially treated with endoscopic third ventriculostomy (ETV), and 102 underwent a temporization procedure (36 with VSGSs and 66 with VRs). The 2 temporization cohorts were similar in terms of sex, race

Management of Ventriculoperitoneal Shunt Infections in Adults: Analysis of Risk Factors Associated With Treatment Failure.

Science.gov (United States)

Pelegrín, Iván; Lora-Tamayo, Jaime; Gómez-Junyent, Joan; Sabé, Nuria; García-Somoza, Dolors; Gabarrós, Andreu; Ariza, Javier; Viladrich, Pedro Fernández; Cabellos, Carmen

2017-04-15

Little is known regarding the optimal treatment of ventriculoperitoneal (VP) shunt infections in adults. Our aim was to assess the efficacy of treatment strategies and to identify factors that predict failure. Retrospective, observational study of patients aged ≥12 years with VP shunt infections (1980 -2014). Therapeutic approaches were classified under 4 headings: only antibiotics (OA), one-stage shunt replacement (OSSR), two-stage shunt replacement (TSSR), and shunt removal without replacement (SR). The primary endpoint was failure of the treatment strategy, defined as the absence of definite cerebrospinal fluid (CSF) sterilization or related mortality. The parameters that predicted failure were analyzed using logistic regression. Of 108 episodes (51% male, median age 50 years), 86 were analyzed. Intravenous antibiotics were administered for a median of 19 days. Eighty episodes were treated using strategies that combined antibiotic and surgical treatment (37 TSSR, 24 SR, 19 OSSR) and 6 with OA. Failure occurred in 30% of episodes, mostly due to lack of CSF sterilization in OSSR and OA groups. Twelve percent died of related causes and 10% presented superinfection of the CSF temporary drainage/externalized peritoneal catheter. TSSR was the most effective strategy when VP shunt replacement was attempted. The only independent risk factor that predicted failure was retention of the VP shunt, regardless of the strategy. This is the largest series of VP shunt infections in adults reported to date. VP shunt removal, particularly TSSR when the patient is shunt dependent, remains the optimal choice of treatment and does not increase morbidity. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Consensus Document of the International Union of Angiology (IUA)-2013. Current concept on the management of arterio-venous management.

Science.gov (United States)

Lee, B B; Baumgartner, I; Berlien, H P; Bianchini, G; Burrows, P; Do, Y S; Ivancev, K; Kool, L S; Laredo, J; Loose, D A; Lopez-Gutierrez, J C; Mattassi, R; Parsi, K; Rimon, U; Rosenblatt, M; Shortell, C; Simkin, R; Stillo, F; Villavicencio, L; Yakes, W

2013-02-01

Arterio-venous malformations (AVMs) are congenital vascular malformations (CVMs) that result from birth defects involving the vessels of both arterial and venous origins, resulting in direct communications between the different size vessels or a meshwork of primitive reticular networks of dysplastic minute vessels which have failed to mature to become 'capillary' vessels termed "nidus". These lesions are defined by shunting of high velocity, low resistance flow from the arterial vasculature into the venous system in a variety of fistulous conditions. A systematic classification system developed by various groups of experts (Hamburg classification, ISSVA classification, Schobinger classification, angiographic classification of AVMs,) has resulted in a better understanding of the biology and natural history of these lesions and improved management of CVMs and AVMs. The Hamburg classification, based on the embryological differentiation between extratruncular and truncular type of lesions, allows the determination of the potential of progression and recurrence of these lesions. The majority of all AVMs are extra-truncular lesions with persistent proliferative potential, whereas truncular AVM lesions are exceedingly rare. Regardless of the type, AV shunting may ultimately result in significant anatomical, pathophysiological and hemodynamic consequences. Therefore, despite their relative rarity (10-20% of all CVMs), AVMs remain the most challenging and potentially limb or life-threatening form of vascular anomalies. The initial diagnosis and assessment may be facilitated by non- to minimally invasive investigations such as duplex ultrasound, magnetic resonance imaging (MRI), MR angiography (MRA), computerized tomography (CT) and CT angiography (CTA). Arteriography remains the diagnostic gold standard, and is required for planning subsequent treatment. A multidisciplinary team approach should be utilized to integrate surgical and non-surgical interventions for optimum

Resolution of clinical symptoms after reopening of an occluded inferior petrosal sinus in a patient with a cavernous sinus dural arteriovenous fistula. A case report.

Science.gov (United States)

Kojima, A; Onozuka, S; Kinoshita, Y

2013-03-01

We describe a rare case with a cavernous sinus (CS) dural arteriovenous fistula (DAVF) in which the clinical symptoms disappeared after the patient underwent reopening of an occluded inferior petrosal sinus (IPS). A 66-year-old woman presented with increased intraocular pressure, chemosis, and proptosis on the left side. Angiography demonstrated a left CS DAVF supplied by the dural branches of bilateral internal carotid arteries. The shunt flow was directed to the superior and inferior ophthalmic veins, while the bilateral IPSs were not opacified. Accordingly, a transvenous embolization of the fistula was attempted. Although the microcatheter was navigated to the cavernous sinus through the occluded left IPS, obliteration of the fistula was unsuccessful because of the failure of superselective catheterization at the fistulous point. However, the final image demonstrated the development of an antegrade shunt flow through the left IPS to the internal jugular vein and disappearance of the retrograde reflux to the superior and inferior ophthalmic veins. The patient's clinical symptoms immediately resolved after the operation, and the symptoms have not recurred during a one-year follow-up period. Inappropriate transvenous embolization of CS DAVFs can result in vascular complications arising from the unintentional redistribution of shunt flow. The present case illustrates that the disappearance of retrograde shunt flow to the ophthalmic veins after reopening of the occluded IPS may be sufficient if a superselective approach fails or is anticipated to result only in an incomplete embolization of the fistulous point.

Intracranial arteriovenous malformation. Contralateral steal phenomena

Energy Technology Data Exchange (ETDEWEB)

Batjer, H H; Devous, M D; Seibert, G B; Purdy, P D; Ajmani, A K; Delarosa, M; Bonte, F J [Texas Univ., Dallas, TX (USA). Southwestern Medical Center

1989-05-01

Sixty-two patients with radiographically proven intracranial arteriovenous malformations underwent preoperative regional cerebral blood flow measurement with {sup 133}Xe signal-photon emission computed tomography. Contralateral regions of hypoperfusion were deteceted in all cases. Steal severity was assessed according to the contralateral steal index (ISteal(c)). ISteal(c) was < 0.7 (severe) in 22 (35%), 0.7-0.8 (intermediate) in 18 (29%), and > 0.8 (mild) in 22 (35%). ISteal(c) was more frequently severe or mild in females and more often intermediate in males in males (p < 0.05). Hyperemic complications were encountered more frequently in patients with intermediate ISteal(c) (p = 0.086). An unfavorable outcome was associated with less severe contralateral steal (p = 0.12). A detailed clinical, radiographic, and hemodynamic profile may help to preperatively identify patients at high risk for a poor surgical outcome. (author).

Pulmonary arteriovenous fistulas

International Nuclear Information System (INIS)

Medeiros Sobrinho, J.H. de; Kambara, A.M.

1987-01-01

Six cases of pulmonary arteriovenous fistulas, isolated, without hemorrhagic hereditary telangiectasia (Rendu-Osler-Weber Symdrome) are reported emphasizing the radiographic, tomographic and angiographic examinations, (M.A.C.) [pt

Coronary Arteriovenous Fistula Causing Hydrops Fetalis

Directory of Open Access Journals (Sweden)

Nilüfer Çetiner

2014-01-01

Full Text Available Fetal heart failure and hydrops fetalis may occur due to systemic arteriovenous fistula because of increased cardiac output. Arteriovenous fistula of the central nervous system, liver, bone or vascular tumors such as sacrococcygeal teratoma were previously reported to be causes of intrauterine heart failure. However, coronary arteriovenous fistula was not reported as a cause of fetal heart failure previously. It is a rare pathology comprising 0.2–0.4% of all congenital heart diseases even during postnatal life. Some may remain asymptomatic for many years and diagnosed by auscultation of a continuous murmur during a routine examination, while a larger fistulous coronary artery opening to a low pressure cardiac chamber may cause ischemia of the affected myocardial region due to steal phenomenon and may present with cardiomyopathy or congestive heart failure during childhood. We herein report a neonate with coronary arteriovenous fistula between the left main coronary artery and the right ventricular apex, who presented with hydrops fetalis during the third trimester of pregnancy.

Evaluation of hepatic steatosis in dogs with congenital portosystemic shunts using Oil-Red-O staining

Science.gov (United States)

Hunt, GB; Luff, J; Daniel, L; Van den Bergh, R.

2015-01-01

The aims of this prospective study were to quantify steatosis in dogs with congenital portosystemic shunts using a fat-specific stain, to compare the amount of steatosis in different lobes of the liver, and to evaluate intra- and inter-Observer variability in lipid point counting. Computer-assisted point counting of lipid droplets was undertaken following Oil-Red-O staining in 21 dogs with congenital portosystemic shunts and 9 control dogs. Dogs with congenital portosystemic shunts had significantly more small lipid droplets ( 9 μ) and lipogranulomas per tissue point (p = 0.023 and 0.01, respectively). In conclusion, computer-assisted counting of lipid droplets following Oil Red O staining of liver biopsy samples allows objective measurement and detection of significant differences between dogs with CPS and normal dogs. This method will allow future evaluation of the relationship between different presentations of CPS (anatomy, age, breed) and lipidosis, as well as the impact of hepatic lipidosis on outcomes following surgical shunt attenuation. PMID:23528942

Long term follow-up of 43 pure dural arteriovenous fistulae (AVF) of the lateral sinus

Energy Technology Data Exchange (ETDEWEB)

Fermand, M; Reizine, D; Melki, J P; Riche, M C; Merland, J J

1987-07-01

Fourty-three patients with arterio-venous fistulae of the dura of the transverse sinus with a complaint of tinnitus are reviewed, with a follow-up of 12 months to 11 years. 34 patients were embolized, 2 treated surgically, and 7 were untreated. Embolization appears to have been beneficial. The benign nature of this abnormality must be emphasized, and serious psychological study of the patient must be made before deciding on therapy.

Genetics Home Reference: capillary malformation-arteriovenous malformation syndrome

Science.gov (United States)

... Institute: How the Heart Works National Institute of Neurological Disorders and Stroke: Arteriovenous Malformation Educational Resources (7 links) Boston Children's Hospital: Arteriovenous Malformation Boston Children's Hospital: Capillary Malformation ...

Indocyanine green videoangiography "in negative": definition and usefulness in spinal dural arteriovenous fistulae.

Science.gov (United States)

Simal Julián, Juan Antonio; Miranda Lloret, Pablo; López González, Antonio; Evangelista Zamora, Rocío; Botella Asunción, Carlos

2013-05-01

Indocyanine green videoangiography (IGV) has proven its effectiveness in the field of exovascular neurosurgery, both in the intracranial and spinal compartment, but is necessary to define a systematic process for the performance of the IGV to facilitate its interpretation during the procedure. We have defined and applied the concept of videoangiography "in negative" (INIGV) to spinal dural arteriovenous fistulae (dAVF) for the detection and treatment of arteriovenous shunts, so called because the first phase is performed with the vessel suggestive of being pathological occluded. A Pentero-operating microscope with near-infrared IGV-integrated system (Carl Zeiss Co., Germany) was used. At our institution, 24 patients were treated for a spinal dAVF between 1995 and 2011, only in the last 4 cases, INIGV was performed. We describe the IGV in negative procedure and show the most illustrative cases. In all cases, the fistula occlusion was confirmed by postoperative selective digital subtraction angiography (DSA). INIGV demonstrate its capacity in detecting vessels not actually arterialized that should be respected and avoid some of the main limitations of the conventional IGV. This is a technical description about an Indocyanine green (ICG) videoangiographic procedure modification that is superior to merely performing ICG before and after clipping of a dAVF. The INIGV results are rapid and easy to interpret procedure and provide great advantages to the dAVF treatment. Nevertheless, further studies are needed with a larger sample size to determine if INIGV may reduce the need to perform immediate postoperative DSA.

Analysis of postural sway in patients with normal pressure hydrocephalus: effects of shunt implantation

Directory of Open Access Journals (Sweden)

Czerwosz L

2009-12-01

Full Text Available Abstract Poor postural balance is one of the major risk factors for falling in normal pressure hydrocephalus (NPH. Postural instability in the clinic is commonly assessed based upon force platform posturography. In this study we focused on the identification of changes in sway characteristics while standing quiet in patients with NPH before and after shunt implantation. Postural sway area and sway radius were analyzed in a group of 9 patients and 46 controls of both genders. Subject's spontaneous sway was recorded while standing quiet on a force platform for 30-60 s, with eyes open and then closed. Both analyzed sway descriptors identified between-group differences and also an effect of shunt implantation in the NPH group. Sway radius and sway area in patients exhibited very high values compared with those in the control group. Importantly, the effect of eyesight in patients was not observed before shunt implantation and reappeared after the surgical treatment. The study documents that static force platform posturography may be a reliable measure of postural control improvement due to shunt surgery.

Traumatic Intrarenal Arteriovenous Fistula Treated by Conservative ...

African Journals Online (AJOL)

1974-06-01

Jun 1, 1974 ... with these vascular lesions.' Varela' in 1928 reported the first case of intrarenal arteriovenous fistula. Arteriovenous fistula of the kidney is an ... and penetrating abdominal trauma, this lesion will be encountered with increasing frequency. Selective renal artery catheterisation aids materially in making the.

Post-traumatic arteriovenous fistula of the hepatic pedicle.

Science.gov (United States)

Ibn Majdoub Hassani, K; Mohsine, R; Belkouchi, A; Bensaid, Y

2010-10-01

Hepatico-portal fistula (HPF) is a rare condition, most often of post-traumatic or iatrogenic origin and occasionally secondary to a ruptured aneurysm of the hepatic artery into the portal vein. HPF in extrahepatic locations often results in portal hypertension (PHT). While Doppler ultrasound, CT angiography, and magnetic resonance angiography are usually demonstrative, arteriography remains indispensable to clarify the exact anatomical configuration. In the treatment of these arteriovenous (AV) fistulas, open surgical approaches have increasingly given way to radiological embolization techniques, especially in intrahepatic locations, but surgery remains indicated for AV fistulas of the hepatic pedicle where maintenance of hepatic arterial flow is a priority of treatment. We report a patient who had an AV fistula of the hepatic pedicle with resultant PHT presenting 5 years after open abdominal trauma. Treatment was surgical; the immediate and long-term postoperative course was uneventful with regression of PHT. Through analysis of this case and a review of the literature, we discuss the clinical, paraclinical, therapeutic, and prognostic features of this lesion. Copyright © 2010. Published by Elsevier Masson SAS.

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

Science.gov (United States)

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Berenstein, Laura Diaz; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2016-01-01

Objective Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. Methods 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3–9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. Results A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=−0.67–−0.70 for all patients on room air, p<0.01 and R=−0.49–−0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. Conclusions There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. Trial Registration Number NCT02135081. PMID:26048877

Flow-regulated versus differential pressure-regulated shunt valves for adult patients with normal pressure hydrocephalus

DEFF Research Database (Denmark)

Ziebell, Morten; Wetterslev, Jørn; Tisell, Magnus

2013-01-01

Since 1965 many ventriculo-peritoneal shunt systems have been inserted worldwide to treat hydrocephalus. The most frequent indication in adults is normal pressure hydrocephalus (NPH), a condition that can be difficult to diagnose precisely. Surgical intervention with flow-regulated and differential...

Surgical management of hydrocephalus secondary to intraventricular hemorrhage in the preterm infant.

Science.gov (United States)

Christian, Eisha A; Melamed, Edward F; Peck, Edwin; Krieger, Mark D; McComb, J Gordon

2016-03-01

OBJECT Posthemorrhagic hydrocephalus (PHH) in the preterm infant remains a major neurological complication of prematurity. The authors first described insertion of a specially designed low-profile subcutaneous ventricular catheter reservoir for temporary management of hydrocephalus in 1983. This report presents the follow-up experience with the surgical management of PHH in this population and describes outcomes both in infants who were stable for permanent shunt insertion and those initially temporized with a ventricular reservoir (VR) prior to permanent ventriculoperitoneal (VP)/ventriculoatrial (VA) shunt placement. METHODS A retrospective review was undertaken of the medical records of all premature infants surgically treated for posthemorrhagic hydrocephalus (PHH) between 1997 and 2012 at Children's Hospital Los Angeles. RESULTS Over 14 years, 91 preterm infants with PHH were identified. Fifty neonates received temporizing measures via a VR that was serially tapped for varying time periods. For the remaining 41 premature infants, VP/VA shunt placement was the first procedure. Patients with a temporizing measure as their initial procedure had undergone CSF diversion significantly earlier in life than those who had permanent shunting as the initial procedure (29 vs 56 days after birth, p hydrocephalus and shunt infection did not statistically differ between the 2 groups. CONCLUSIONS Patients with initial VR insertion as a temporizing measure received a CSF diversion procedure significantly earlier than those who received a permanent shunt as their initial procedure. Otherwise, the outcomes with regard to shunt revisions, loculated hydrocephalus, and shunt infection were not different for the 2 groups.

Congenital Intrahepatic Portosystemic Shunts

Energy Technology Data Exchange (ETDEWEB)

Lee, Woong Hee; Kim, Young Tong; Jou, Sung Shick; Shin, Hyeong Cheol [Soonchunhyang University, Asan (Korea, Republic of)

2008-12-15

Intrahepatic portosystemic shunts are an anomalous connection between the portal vein and hepatic vein/IVC, which may be either congenital or acquired secondary to liver cirrhosis or portal hypertension. Cases of congenital intrahepatic shunts are usually encountered in children and may spontaneously resolve. We report 5 cases of congenital intrahepatic portosystemic shunts in neonates and an adult

Long term follow-up of 43 pure dural arteriovenous fistulae (AVF) of the lateral sinus

International Nuclear Information System (INIS)

Fermand, M.; Reizine, D.; Melki, J.P.; Riche, M.C.; Merland, J.J.

1987-01-01

Fourty-three patients with arterio-venous fistulae of the dura of the transverse sinus with a complaint of tinnitus are reviewed, with a follow-up of 12 months to 11 years. 34 patients were embolized, 2 treated surgically, and 7 were untreated. Embolization appears to have been beneficial. The benign nature of this abnormality must be emphasized, and serious psychological study of the patient must be made before deciding on therapy. (orig.)

Rate of shunt revision as a function of age in patients with shunted hydrocephalus due to myelomeningocele.

Science.gov (United States)

Dupepe, Esther B; Hopson, Betsy; Johnston, James M; Rozzelle, Curtis J; Jerry Oakes, W; Blount, Jeffrey P; Rocque, Brandon G

2016-11-01

OBJECTIVE It is generally accepted that cerebrospinal fluid shunts fail most frequently in the first years of life. The purpose of this study was to describe the risk of shunt failure for a given patient age in a well-defined cohort with shunted hydrocephalus due to myelomeningocele (MMC). METHODS The authors analyzed data from their institutional spina bifida research database including all patients with MMC and shunted hydrocephalus. For the entire population, the number of shunt revisions in each year of life was determined. Then the number of patients at risk for shunt revision during each year of life was calculated, thus enabling them to calculate the rate of shunt revision per patient in each year of life. In this way, the timing of all shunt revision operations for the entire clinic population and the likelihood of having a shunt revision during each year of life were calculated. RESULTS A total of 655 patients were enrolled in the spina bifida research database, 519 of whom had a diagnosis of MMC and whose mean age was 17.48 ± 11.7 years (median 16 years, range 0-63 years). Four hundred seventeen patients had had a CSF shunt for the treatment of hydrocephalus and thus are included in this analysis. There were 94 shunt revisions in the 1st year of life, which represents a rate of 0.23 revisions per patient in that year. The rate of shunt revision per patient-year initially decreased as age increased, except for an increase in revision frequency in the early teen years. Shunt revisions continued to occur as late as 43 years of age. CONCLUSIONS These data substantiate the idea that shunt revision surgeries in patients with MMC are most common in the 1st year of life and decrease thereafter, except for an increase in the early teen years. A persistent risk of shunt failure was observed well into adult life. These findings underscore the importance of routine follow-up of all MMC patients with shunted hydrocephalus and will aid in counseling patients and

Overall outcomes following early interventions for intracranial arteriovenous malformations with hematomas.

Science.gov (United States)

Bir, Shyamal C; Maiti, Tanmoy Kumar; Konar, Subhas; Nanda, Anil

2016-01-01

We evaluated the timing and predictors of surgical intervention for intracranial arteriovenous malformations (AVM) with hematoma. A ruptured intracranial AVM with hematoma is an emergency condition, and the optimal timing for surgical intervention is not well understood. In addition, the outcome predictors of surgical intervention have rarely been reported. We identified and analyzed 78 patients treated with microsurgical resection for pathologically proven AVM at Louisiana State University Health in Shreveport from February 1992 to December 2004. All 78 patients were diagnosed with ruptured AVM before surgery. The independent variables, including patient demographics, timing of surgery, location of the AVM and comorbidities were analyzed to assess outcome. The results of this series revealed that surgical intervention after 48hours resulted in poor outcomes for patients with hematoma, following a ruptured AVM. Several other prognostic factors, including younger age (11-40years), Spetzler-Martin Grade I and II, and AVM in a supratentorial location, had significant positive effects on outcomes. However, hypertension, smoking, and a prior embolization showed significant negative effects on outcomes after surgery. The multiple logistic regression analyses also revealed that the timing of surgical intervention had a significant effect on outcomes in patients with hematoma following ruptured AVM. Early intervention is the key to success in these patients. Published by Elsevier Ltd.

Treatment of hydrocephalus determined by the European Orbis Sigma Valve II survey: a multicenter prospective 5-year shunt survival study in children and adults in whom a flow-regulating shunt was used

NARCIS (Netherlands)

Hanlo, Patrick W.; Cinalli, Giuseppe; Vandertop, W. Peter; Faber, Joop A. J.; Bøgeskov, Lars; Børgesen, Svend E.; Boschert, Jürgen; Chumas, Paul; Eder, Hans; Pople, Ian K.; Serlo, Willy; Vitzthum, Eckehard

2003-01-01

OBJECT: The goal of this study was to evaluate the long-term results of a flow-regulating shunt (Orbis Sigma Valve [OSV] II Smart Valve System; Integra NeuroSciences, Sophia Antipolis, France) in the treatment of hydrocephalus, whether it was a first insertion procedure or surgical revision of

[Multiple coronary arteriovenous fistulae. Hazard or predetermination?].

Science.gov (United States)

Rangel, Alberto; Muñoz-Castellanos, Luis; Solorio, Sergio

2003-01-01

The authors present the clinical cases of three adult patients (49, 53 and 61 year-old), with rheumatic cardiac valvulopathy, and bilateral coronary arteriovenous fistulae draining in the main pulmonary artery. Based on documental investigation, the authors speculate about the predeterminate origin of coronary arteriovenous fistulae. At first glance, it seems obvious that congenital cardiopathies occur at random, i.e., embryonic development deviate or stops due to unknown reasons, originating the persistence of lacunar blood spaces prior to the development of coronary arteries cords. There are two factors involved in the genesis of congenital malformations: a genomic preexisting factor and the presence of an environmental precipitating factor, i.e., isolated pulmonary valve atresia or left ventricular hypoplastic syndrome, with mitral and aortic valve stenosis, can predispose development of coronary arteriovenous fistulae. Recently, the question has been raised whether there is a relation of coronary arteries fistulae with: ethnic groups, hereditary gigantism, autoimmune diseases, such as polymyositis, hereditary hemorrhagic telangiectasia, and apical hypertrophic myocardiopathy. Coronary arteriovenous fistulae, as well as some congenital cardiopathies, could be due to chromosome alterations or might be related to hereditary diseases, such as hemorrhagic telangiectasia, induced by a disturbed genetic program. Although, there is no concrete evidence that a genetic factor is related to the development of coronary arteriovenous fistulae, there are signs that suggest that such a possibility could be investigated.

Transjugular intrahepatic portosystemic shunt

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Park, Jae Hyung; Han, Joon Koo; Chung, Jin Wook; Han, Man Chung [Seoul National University College of Medicidne, Seoul (Korea, Republic of)

1992-05-15

As a new interventional procedure for the control of variceal bleeding, a portosystemic shunt can be established with the installment of metallic stent through the transjugular approach. In order to evaluate the clinical usefulness of the procedure, transjugular intrahepatic portosystemic shunt procedure were performed in 5 patients with variceal bleeding due to liver cirrhosis. The metallic stents were mainly a self expandable Wallstent (Schneider, Switzerland), An 8 to 10 mm shunt was formed by the insertion of the stent and balloon dilatation after puncture of the proximal portal vein from the right or middle hepatic vein. The patency of the shunt was proven by portography after the procedure. The portal pressure measured in 3 patients before and after the procedure improved with decrease from 31 mmHg to 25 mmHg. The procedure failed in 1 patient due to pre-existing portal vein thrombosis. During the follow-up period from 1 month to 4 months, shunts were patent in all 4 patients. However, hepatic encephalopathy occurred in one patient one week following the procedure. Though the follow-up period was not long enough for full evaluation, we found the transjugular intrahepatic portosystemic shunt was a safe and effective procedure for the control of variceal bleeding by lowering the portal pressure. For the appropriate application for this procedure, the optimal size of the shunt and optical degree of the resultant decompression are yet to be determined in the future.

Molecular and cellular biology of cerebral arteriovenous malformations: a review of current concepts and future trends in treatment.

Science.gov (United States)

Rangel-Castilla, Leonardo; Russin, Jonathan J; Martinez-Del-Campo, Eduardo; Soriano-Baron, Hector; Spetzler, Robert F; Nakaji, Peter

2014-09-01

Arteriovenous malformations (AVMs) are classically described as congenital static lesions. However, in addition to rupturing, AVMs can undergo growth, remodeling, and regression. These phenomena are directly related to cellular, molecular, and physiological processes. Understanding these relationships is essential to direct future diagnostic and therapeutic strategies. The authors performed a search of the contemporary literature to review current information regarding the molecular and cellular biology of AVMs and how this biology will impact their potential future management. A PubMed search was performed using the key words "genetic," "molecular," "brain," "cerebral," "arteriovenous," "malformation," "rupture," "management," "embolization," and "radiosurgery." Only English-language papers were considered. The reference lists of all papers selected for full-text assessment were reviewed. Current concepts in genetic polymorphisms, growth factors, angiopoietins, apoptosis, endothelial cells, pathophysiology, clinical syndromes, medical treatment (including tetracycline and microRNA-18a), radiation therapy, endovascular embolization, and surgical treatment as they apply to AVMs are discussed. Understanding the complex cellular biology, physiology, hemodynamics, and flow-related phenomena of AVMs is critical for defining and predicting their behavior, developing novel drug treatments, and improving endovascular and surgical therapies.

Shunt detection and measurement

International Nuclear Information System (INIS)

Grossman, W.

1986-01-01

Detection, localization, and quantification of intracardiac shunts are an integral part of the hemodynamic evaluation of patients with congenital heart disease. In most cases, an intracardiac shunt is suspected on the basis of the clinical evaluation of the patient prior to catheterization. However, there are several circumstances in which data obtained at catheterization should alert the cardiologist to look for a shunt that previously had not been suspected

Automated double-cone-beam CT fusion technique. Enhanced evaluation of glue distribution in cases of spinal dural arteriovenous fistula (SDAVF) embolisation

International Nuclear Information System (INIS)

Farago, Giuseppe; Caldiera, V.; Antozzi, C.; Bellino, A.; Innocenti, A.; Ciceri, E.

2017-01-01

Spinal dural arteriovenous fistulas (SDAVFs) are acquired diseases that represent the majority of all arteriovenous spinal shunts, leading to progressive and disabling myelopathy. Treatment is focused on accurately disconnecting the fistula point. We present our experience with the double-cone-beam CT fusion technique successfully applied to evaluate treatment results in a series of SDAVFs. Between November 2011 and December 2015 we performed double-DynaCT acquisition (pre- and post-embolisation) in 12 cases of SDAVF. A successful DynaCT fusion technique was only achieved in the group of patients with pre- and post-treatment images acquired at the same time as the treatment session, under general anaesthesia (4/12). DynaCT performed on different days proved to be inadequate for the automated fusion technique because of changes in the body position (8/12). A pre-treatment flat-panel cone-beam CT with contrast, at the time of diagnostic angiography, can be very helpful to detect the correct level of the fistula and the relationship between the fistula and the surrounding structures. In case of the endovascular approach, additional post-treatment native acquisition merged with the pre-treatment acquisition (double-cone-beam CT fusion technique) permits to immediately evaluate the distribution of the glue cast and to confirm the success of the procedure. (orig.)

Automated double-cone-beam CT fusion technique. Enhanced evaluation of glue distribution in cases of spinal dural arteriovenous fistula (SDAVF) embolisation

Energy Technology Data Exchange (ETDEWEB)

Farago, Giuseppe [Foundation Neurological Institute ' ' C. Besta' ' , Department of Interventional Neuroradiology, Milan (Italy); Fondazione IRCCS Istituto Neurologico Carlo Besta, Department of Interventional Neuroradiology, Milan (Italy); Caldiera, V. [Foundation Neurological Institute ' ' C. Besta' ' , Department of Interventional Neuroradiology, Milan (Italy); Antozzi, C.; Bellino, A. [Foundation Neurological Institute ' ' C. Besta' ' , Department of Neuroimmunology and Neuromuscular Diseases, Milan (Italy); Innocenti, A. [Foundation Neurological Institute ' ' C. Besta' ' , Department of Neuro-Oncology, Milan (Italy); Ciceri, E. [Foundation Neurological Institute ' ' C. Besta' ' , Department of Interventional Neuroradiology, Milan (Italy); Azienda Ospedaliera Universitaria Integrata Borgo Trento, Department of Neuroradiology, Verona (Italy)

2017-05-15

Spinal dural arteriovenous fistulas (SDAVFs) are acquired diseases that represent the majority of all arteriovenous spinal shunts, leading to progressive and disabling myelopathy. Treatment is focused on accurately disconnecting the fistula point. We present our experience with the double-cone-beam CT fusion technique successfully applied to evaluate treatment results in a series of SDAVFs. Between November 2011 and December 2015 we performed double-DynaCT acquisition (pre- and post-embolisation) in 12 cases of SDAVF. A successful DynaCT fusion technique was only achieved in the group of patients with pre- and post-treatment images acquired at the same time as the treatment session, under general anaesthesia (4/12). DynaCT performed on different days proved to be inadequate for the automated fusion technique because of changes in the body position (8/12). A pre-treatment flat-panel cone-beam CT with contrast, at the time of diagnostic angiography, can be very helpful to detect the correct level of the fistula and the relationship between the fistula and the surrounding structures. In case of the endovascular approach, additional post-treatment native acquisition merged with the pre-treatment acquisition (double-cone-beam CT fusion technique) permits to immediately evaluate the distribution of the glue cast and to confirm the success of the procedure. (orig.)

Pathological Predictors of Shunt Stenosis and Hepatic Encephalopathy after Transjugular Intrahepatic Portosystemic Shunt

Directory of Open Access Journals (Sweden)

Fuliang He

2016-01-01

Full Text Available Background. Transjugular intrahepatic portosystemic shunt (TIPS is an artificial channel from the portal vein to the hepatic vein or vena cava for controlling portal vein hypertension. The major drawbacks of TIPS are shunt stenosis and hepatic encephalopathy (HE; previous studies showed that post-TIPS shunt stenosis and HE might be correlated with the pathological features of the liver tissues. Therefore, we analyzed the pathological predictors for clinical outcome, to determine the risk factors for shunt stenosis and HE after TIPS. Methods. We recruited 361 patients who suffered from portal hypertension symptoms and were treated with TIPS from January 2009 to December 2012. Results. Multivariate logistic regression analysis showed that the risk of shunt stenosis was increased with more severe inflammation in the liver tissue (OR, 2.864; 95% CI: 1.466–5.592; P=0.002, HE comorbidity (OR, 6.266; 95% CI, 3.141–12.501; P<0.001, or higher MELD score (95% CI, 1.298–1.731; P<0.001. Higher risk of HE was associated with shunt stenosis comorbidity (OR, 6.266; 95% CI, 3.141–12.501; P<0.001, higher stage of the liver fibrosis (OR, 2.431; 95% CI, 1.355–4.359; P=0.003, and higher MELD score (95% CI, 1.711–2.406; P<0.001. Conclusion. The pathological features can predict individual susceptibility to shunt stenosis and HE.

Splenic arteriovenous fistula treated with percutaneous transarterial embolization

DEFF Research Database (Denmark)

Madsen, M.A.; Frevert, S.; Madsen, P.L.

2008-01-01

Splenic arteriovenous fistula is a rare complication following splenectomy. We report a case of a large splenic arteriovenous fistula 23 years after splenectomy in a 50-year old male with abdominal pain, gastro-intestinal bleeding, ascites, diarrhoea, dyspnoea, portal hypertension and heart failure...

30 CFR 56.6401 - Shunting.

Science.gov (United States)

2010-07-01

... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Electric Blasting § 56.6401 Shunting. Except during testing— (a) Electric detonators shall be kept shunted until connected to the blasting line or wired into a blasting round; (b) Wired rounds shall be kept shunted until...

Arteriovenous malformation of face

Directory of Open Access Journals (Sweden)

Ashok Kumar

2017-01-01

Full Text Available Arteriovenous malformations (AVMs are rare congenital vascular malformations accounting only 1.5% of all vascular anomalies with 50% occurrence in the oral and maxillofacial region. It usually results from birth defects of the vasculature. A literature search revealed only few case reports of AVMs in the facial region. Lack of meticulous diagnosis, scarcity of knowledge, and paucity of literature can result in their exsanguinations leading to fatal hemorrhagic incidents after various dental procedures such as tooth extraction, surgical intervention, puncture wound, or blunt injury in involved area. The present case describes the accidental diagnosis of asymptomatic high-flow AVMs in the facial region of pediatric patient reported primarily for the treatment of periapical abscess. This case report is unique because although there was no history of bleeding episodes, thorough examination and investigations diagnosed it as high-flow vascular malformation. It is important for the dental practitioner to be aware of AVM which may be present in the head and neck region that can produce fatal bleeding episodes during various dental procedures. Proper diagnosis of AVMs through complete history, precise clinical examination, and advanced imaging modalities can help in preventing serious life-threatening complications.

Rendu-Osler-Weber syndrome presenting with pulmonary arteriovenous fistula

International Nuclear Information System (INIS)

Halefoglu, A.M.

2005-01-01

A pulmonary arteriovenous fistula is an abnormal connection between pulmonary arteries and veins. Patients with Rendu-Osler-Weber syndrome may present with this vascular malformation, which is a typical finding of the disease. Approximately 5-15% of Rendu-Osler-Weber syndrome patients have pulmonary arteriovenous malformations (AVM) and there is usually a family history of AVM in these patients. The malformations are usually located in the lower lobes. In this paper, I describe a 49-year-old male patient with dyspnoea, cough, haemoptysis and epistaxis. Physical examination showed nasal telangiectasias, cyanosis of the lips and nails, and a systolic bruit over the left lung. Chest X-ray revealed a 5-cm mass in the left lower lobe and after magnetic resonance examination, together with 3-D magnetic resonance angiography, it was demonstrated to be a pulmonary arteriovenous fistula. The history of a niece with a similar history of suspected pulmonary arteriovenous fistula led me to consider the possibility of Rendu-Osler-Weber syndrome presenting with a pulmonary arteriovenous fistula. Copyright (2005) Blackwell Science Pty Ltd

Arteriovenous Malformation of the Pancreas

Directory of Open Access Journals (Sweden)

Alexandros Charalabopoulos

2011-01-01

Full Text Available Pancreatic arteriovenous malformation (PAVM is a very rare and mostly congenital lesion, with less than 80 cases described in the English-published literature. It is defined as a tumorous vascular abnormality that is constructed between an anomalous bypass anastomosis of the arterial and venous networks within the pancreas. It represents about 5% of all arteriovenous malformations found in the gastrointestinal tract. Herein, we present a 64-year-old patient with symptomatic PAVM involving the body and tail of the organ, which was successfully treated by transcatheter arterial embolization. The disease spectrum and review of the literature are also presented.

Transcatheter Closure of a Chronic Iatrogenic Arteriovenous Fistula Between the Carotid Artery and the Brachiocephalic Vein with an Amplatzer Duct Occluder in Combination with a Carotid Stent

International Nuclear Information System (INIS)

Stasek, Josef; Lojik, Miroslav; Bis, Josef; Horak, David; Dusek, Jaroslav; Brtko, Miroslav; Polansky, Pavel; Babu, Anush; Vojacek, Jan

2009-01-01

We report an original method of transcatheter closure of an arteriovenous fistula using the combination of an Amplatzer PDA occluder and a carotid stent. The fistula was between the left carotid artery and the brachiocephalic vein. The patient had significant left-to-right shunt and was highly symptomatic. Due to the large orifice and pseudoaneurysmatic enlargement of the fistula, we had to use a large Amplatzer PDA occluder and the protruding part of the PDA device disk had to be covered with a carotid stent. The fistula was completely closed. The patient stopped having symptoms and, 2 years after the procedure, the effect persists.

Clinical results of the transjugular intrahepatic portosystemic shunt

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Park, Auh Whan; Sim, Jae In; Ryeom, Hun Kyu; Kim, Yong Joo [Kyungpook National University Hospital, Daegu (Korea, Republic of)

1994-04-15

To evaluate the clinical results of transjugular intrahepatic portosystemic shunt(TIPS) for the control of variceal bleeding. TIPS creation was attempted in 23 patients with endoscopically confirmed variceal bleeding. Most patients had multiple episodes of bleeding in the past and have been treated with multiple endoscopic sclerotherapies. Pre-and post-procedural hepatic and portal vein pressures were measured. After creation of TIPS patients were followed up at regular intervals. TIPS has been successfully accomplished in 22 of 23 patients using Wallstent(n = 21) and Strecker stent(n = 1). Immediate bleeding control was achieved in all patients with shunt creation. No procedure-related complication was noted. Portal vein pressure was reduced from 30.7 {+-} 5.8 mmHg to 20.8 {+-} 4.7 mmHg. The mean pressure gradient of portosystemic shunt dropped from 22.8 {+-} 6.0 prior to TIPS to 12.2 {+-} 4.1 immediately after. During the follow-up period (6-556 days, mean; 10 months), seven patients died; progressive hepatic failure (n 4), variceal rebleeding (n = 2), and respiratory failure(n = 1). Hepatic encephalopathy after TIPS was noted in 7 patients(31.8%). Variceal rebleeding occurred in 3 patients(13.6%). The remaining 15 patients have survived an average of 11 months. This results suggest that TIPS is a safe and effective method for lowering portal pressure and controlling variceal bleeding. Furthermore if these initial results are encouraged by further long-term observation, TIPS could replace endoscopic and risky surgical intervention.

Portal hypertension: A critical appraisal of shunt procedures with emphasis on distal splenorenal shunt in children

Directory of Open Access Journals (Sweden)

Nitin Sharma

2014-01-01

Full Text Available Background: Extrahepatic portal venous obstruction (EHPVO is the most common cause of pediatric portal hypertension. We analyzed the investigative protocol and results of portosystemic shunts in this group of patients. Materials and Methods: A total of 40 consecutive children aged below 12 years operated with a diagnosis of extra-hepatic portal hypertension formed the study group. Historical data and clinical data were collected. All patients underwent upper gastrointestinal endoscopy, ultrasound Doppler and computed tomographic portogram pre-operatively and post-operatively. Results with respect to shunt patency, hypersplenism and efficacy of different radiological investigations were collected. Results: A total of 40 patients, 28 boys and 12 girls constituted the study group. Lienorenal shunt (LRS was performed in 14 patients; distal splenorenal shunt in 21 patients and side-to-side lienorenal shunt in 4 patients, inferior mesenteric renal shunt was performed in 1 patient. Follow-up ranged from 36 to 70 months. At a minimum follow-up of 3 years, 32 (80% patients were found to have patent shunts. Patent shunts could be visualized in 30/32 patients with computer tomographic portogram (CTP and 28/32 with ultrasound. Varices regressed completely in 26/32 patients and in the rest incomplete regression was seen. Spleen completely regressed in 19/25 patients. Hypersplenism resolved in all patients with patent shunts. Conclusions: Portosystemic shunting in children with EHPVO is a viable option. While long-term cure rates are comparable with sclerotherapy, repeated hospital visits are reduced with one time surgery. Pre-operative and post-operative assessment can be performed with complimentary use of ultrasound, CTP and endoscopy.

Liver perfusion scintigraphy prior to and after transjugular intrahepatic portosystemic shunts (TIPS) in patients with portal hypertension

International Nuclear Information System (INIS)

Willkomm, P.; Schomburg, A.; Reichmann, K.; Bangard, M.; Overbeck, B.; Biersack, H.J.; Brensing, K.A.; Sauerbruch, T.

2000-01-01

Purpose: This investigation was performed to compare the hemodynamic results of the transjugular intrahepatic portosystemic shunt, a new interventional treatment for portal hypertension, with those observed after the established surgical shunt interventions. Methods: We examined 22 patients with portal hypertension due to liver cirrhosis before and after elective TIPS by liver perfusion scintigraphy. The relative portal perfusion was determined before and after the shunt procedure. Additionally, we measured the portal pressure gradient (PPG: Portal-central venous pressure, mmHg). Results: Prior to TIPS, the relative portal perfusion was significantly reduced to 22±9.1%. After the intervention we calculated values of 23.1±10.7% in the TIPS-group (p=0.67; not significant). In spite of unchanged portal perfusion, the portal pressure was significantly (p [de

Utility of time-resolved three-dimensional magnetic resonance digital subtraction angiography without contrast material for assessment of intracranial dural arterio-venous fistula

International Nuclear Information System (INIS)

Hori, Masaaki; Aoki, Shigeki; Nakanishi, Atsushi; Shimoji, Keigo; Kamagata, Koji; Houshito, Haruyoshi; Kuwatsuru, Ryohei; Oishi, Hidenori; Arai, Hajime

2011-01-01

Background: Intracranial dural arteriovenous fistula (DAVF) is an arteriovenous shunting disease of the dura. Magnetic resonance angiography (MRA) is expected to be a safer alternative method in evaluation of DAVF, compared with invasive intra-arterial digital subtraction angiography (IADSA). Purpose: To evaluate the diagnostic use of time-spatial labeling inversion pulse (Time-SLIP) three-dimensional (3D) magnetic resonance digital subtraction angiography (MRDSA) without contrast material in six patients with DAVF. Material and Methods: Images for 3D time-of-flight MRA, which has been a valuable tool for the diagnosis of DAVF but provide little or less hemodynamic information, and Time-SLIP 3D MRDSA, were acquired for each patient. The presence, side, and grade of the disease were evaluated according to IADSA. Results: In all patients, the presence and side of the DAVF were correctly identified by both 3D time-of-flight MRA and Time-SLIP 3D MRDSA. Cortical reflux present in a patient with a grade 2b DAVF was not detected by Time-SLIP 3D MRDSA, when compared with IADSA findings. Conclusion: Time-SLIP 3D MRDSA provides hemodynamic information without contrast material and is a useful complementary tool for diagnosis of DAVF

Alteration of brain viscoelasticity after shunt treatment in normal pressure hydrocephalus

Energy Technology Data Exchange (ETDEWEB)

Freimann, Florian Baptist; Sprung, Christian [Charite - University Medicine Berlin, Campus Virchow-Klinikum, Neurosurgical Department, Berlin (Germany); Streitberger, Kaspar-Josche; Klatt, Dieter; Sack, Ingolf [Charite - University Medicine Berlin, Campus Charite Mitte, Department of Radiology, Berlin (Germany); Lin, Kui; McLaughlin, Joyce [Rensselaer Polytechnic Institute, Mathematics Department, Troy, NY (United States); Braun, Juergen [Charite - University Medicine Campus Benjamin Franklin, Institute of Medical Informatics, Berlin (Germany)

2012-03-15

Normal pressure hydrocephalus (NPH) represents a chronic neurological disorder with increasing incidence. The symptoms of NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid. However, the pathogenesis of NPH is not yet fully elucidated, and the clinical response of shunt treatment is hard to predict. According to current theories of NPH, altered mechanical properties of brain tissue seem to play an important role. Magnetic resonance elastography (MRE) is a unique method for measuring in vivo brain mechanics. In this study cerebral MRE was applied to test the viscoelastic properties of the brain in 20 patients with primary (N = 14) and secondary (N = 6) NPH prior and after (91 {+-} 16 days) shunt placement. Viscoelastic parameters were derived from the complex modulus according to the rheological springpot model. This model provided two independent parameters {mu} and {alpha}, related to the inherent rigidity and topology of the mechanical network of brain tissue. The viscoelastic parameters {mu} and {alpha} were found to be decreased with -25% and -10%, respectively, compared to age-matched controls (P < 0.001). Interestingly, {alpha} increased after shunt placement (P < 0.001) to almost normal values whereas {mu} remained symptomatically low. The results indicate the fundamental role of altered viscoelastic properties of brain tissue during disease progression and tissue repair in NPH. Clinical improvement in NPH is associated with an increasing complexity of the mechanical network whose inherent strength, however, remains degraded. (orig.)

Alteration of brain viscoelasticity after shunt treatment in normal pressure hydrocephalus

International Nuclear Information System (INIS)

Freimann, Florian Baptist; Sprung, Christian; Streitberger, Kaspar-Josche; Klatt, Dieter; Sack, Ingolf; Lin, Kui; McLaughlin, Joyce; Braun, Juergen

2012-01-01

Normal pressure hydrocephalus (NPH) represents a chronic neurological disorder with increasing incidence. The symptoms of NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid. However, the pathogenesis of NPH is not yet fully elucidated, and the clinical response of shunt treatment is hard to predict. According to current theories of NPH, altered mechanical properties of brain tissue seem to play an important role. Magnetic resonance elastography (MRE) is a unique method for measuring in vivo brain mechanics. In this study cerebral MRE was applied to test the viscoelastic properties of the brain in 20 patients with primary (N = 14) and secondary (N = 6) NPH prior and after (91 ± 16 days) shunt placement. Viscoelastic parameters were derived from the complex modulus according to the rheological springpot model. This model provided two independent parameters μ and α, related to the inherent rigidity and topology of the mechanical network of brain tissue. The viscoelastic parameters μ and α were found to be decreased with -25% and -10%, respectively, compared to age-matched controls (P < 0.001). Interestingly, α increased after shunt placement (P < 0.001) to almost normal values whereas μ remained symptomatically low. The results indicate the fundamental role of altered viscoelastic properties of brain tissue during disease progression and tissue repair in NPH. Clinical improvement in NPH is associated with an increasing complexity of the mechanical network whose inherent strength, however, remains degraded. (orig.)

Aqueous shunts for glaucoma.

Science.gov (United States)

Tseng, Victoria L; Coleman, Anne L; Chang, Melinda Y; Caprioli, Joseph

2017-07-28

single-plate without oral corticosteroids, 1 trial; double-plate versus single-plate, 1 trial; and pressure-ridge versus double-plate with tube ligation, 1 trial). Information was insufficient to conclude whether there are differences between aqueous shunts and trabeculectomy for glaucoma treatment. While the Baerveldt implant may lower IOP more than the Ahmed implant, the evidence was of moderate-certainty and it is unclear whether the difference in IOP reduction is clinically significant. Overall, methodology and data quality among existing randomized controlled trials of aqueous shunts was heterogeneous across studies, and there are no well-justified or widely accepted generalizations about the superiority of one surgical procedure or device over another.

Validation of an ultrasound dilution technology for cardiac output measurement and shunt detection in infants and children.

Science.gov (United States)

Lindberg, Lars; Johansson, Sune; Perez-de-Sa, Valeria

2014-02-01

To validate cardiac output measurements by ultrasound dilution technology (COstatus monitor) against those obtained by a transit-time ultrasound technology with a perivascular flow probe and to investigate ultrasound dilution ability to estimate pulmonary to systemic blood flow ratio in children. Prospective observational clinical trial. Pediatric cardiac operating theater in a university hospital. In 21 children (6.1 ± 2.6 kg, mean ± SD) undergoing heart surgery, cardiac output was simultaneously recorded by ultrasound dilution (extracorporeal arteriovenous loop connected to existing arterial and central venous catheters) and a transit-time ultrasound probe applied to the ascending aorta, and when possible, the main pulmonary artery. The pulmonary to systemic blood flow ratio estimated from ultrasound dilution curve analysis was compared with that estimated from transit-time ultrasound technology. Bland-Altman analysis of the whole cohort (90 pairs, before and after surgery) showed a bias between transit-time ultrasound (1.01 ± 0.47 L/min) and ultrasound dilution technology (1.03 ± 0.51 L/min) of -0.02 L/min, limits of agreement -0.3 to 0.3 L/min, and percentage error of 31%. In children with no residual shunts, the bias was -0.04 L/min, limits of agreement -0.28 to 0.2 L/min, and percentage error 19%. The pooled co efficient of variation was for the whole cohort 3.5% (transit-time ultrasound) and 6.3% (ultrasound dilution), and in children without shunt, it was 2.9% (transit-time ultrasound) and 4% (ultrasound dilution), respectively. Ultrasound dilution identified the presence of shunts (pulmonary to systemic blood flow ≠ 1) with a sensitivity of 100% and a specificity of 92%. Mean pulmonary to systemic blood flow ratio by transit-time ultrasound was 2.6 ± 1.0 and by ultrasound dilution 2.2 ± 0.7 (not significant). The COstatus monitor is a reliable technique to measure cardiac output in children with high sensitivity and specificity for detecting the

Over-drainage and persistent shunt-dependency in patients with idiopathic intracranial hypertension treated with shunts and bariatric surgery.

Science.gov (United States)

Roth, Jonathan; Constantini, Shlomi; Kesler, Anat

2015-01-01

Idiopathic intracranial hypertension (IIH) may lead to visual impairment. Shunt surgery is indicated for refractory IIH-related symptoms that persist despite medical treatment, or those presenting with significant visual decline. Obesity is a risk factor for IIH; a reduction in weight has been shown to improve papilledema. Bariatric surgery (BS) has been suggested for treating IIH associated with morbid obesity. In this study, we describe a high rate of over-drainage (OD) seen in patients following shunts and BS. The study cohort includes 13 patients with IIH that underwent shunt surgery for treatment of the IIH-related symptoms. Six patients underwent BS in addition to the shunt surgery (but not concomitantly). Seven patients had only shunt surgeries with no BS. Data were collected retrospectively. BS effectively led to weight reduction (body mass index decreasing from 43 ± 4 to 28 ± 5). Patients undergoing BS had 1-6 (2.5 ± 1.9) shunt revisions for OD following BS, as opposed to 0-3 (1.4 ± 1.1) revisions prior to BS over similar time spans (statistically insignificant difference), and 0-6 (1.6 ± 2.5) revisions among the non-BS patients over a longer time span (statistically insignificant difference). Two patients in the BS group underwent shunt externalization and closure; however, they proved to be shunt-dependent. Patients with IIH that undergo shunt surgery and BS (not concomitantly) may suffer from OD symptoms, necessitating multiple shunt revisions, and valve upgrades. Despite BS being a valid primary treatment for some patients with IIH, among shunted patients, BS may not lead to resolution of IIH-related symptoms and patients may remain shunt-dependent.

A modified Glenn shunt reduces right ventricular stroke work during left ventricular assist device therapy.

Science.gov (United States)

Schiller, Petter; Vikholm, Per; Hellgren, Laila

2016-03-01

Right ventricular (RV) failure is a major cause of morbidity and mortality after left ventricular assist device (LVAD) placement and remains hard to predict. We hypothesized that partial surgical exclusion of the RV with a modified Glenn shunt during LVAD treatment would reduce RV stroke work. An LVAD was implanted in eight pigs and a modified Glenn shunt was constructed. A conductance pressure-volume catheter was placed in the right ventricle through the apex. Haemodynamic data and pressure-volume loops were obtained at the following time periods: (i) baseline, (ii) open shunt, (iii) LVAD with closed shunt and (iii) LVAD and open shunt. During LVAD therapy, the right atrial (RA) pressure increased from 9 mmHg (9-9) to 15 mmHg (12-15), P = 0.01. RV stroke volume increased from 30 ml (29-40) to 51 ml (42-53), P work increased to 708 mmHg ml (654-1193) from 535 mmHg ml (424-717), P = 0.04, compared with baseline. During LVAD therapy in combination with a Glenn shunt, the RA pressure decreased from 15 mmHg (12-15) to 10 mmHg (7-11) when compared with LVAD therapy only, P = 0.01. A decrease in RV stroke work from 708 mmHg ml (654-1193) to 465 mmHg ml (366-711), P = 0.04, was seen when the LVAD was combined with a shunt, not significantly different from the baseline value (535 mmHg ml). The developed pressure in the right ventricle decreased from 29 mmHg (26-32) to 21 mmHg (20-24), P work during the use of the shunt with LVAD treatment. A modified Glenn shunt reduced RV volumes, RV stroke work and RA pressure during LVAD therapy in an experimental model of heart failure in pigs. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Flux shunts for undulators

International Nuclear Information System (INIS)

Hoyer, E.; Chin, J.; Hassenzahl, W.V.

1993-05-01

Undulators for high-performance applications in synchrotron-radiation sources and periodic magnetic structures for free-electron lasers have stringent requirements on the curvature of the electron's average trajectory. Undulators using the permanent magnet hybrid configuration often have fields in their central region that produce a curved trajectory caused by local, ambient magnetic fields such as those of the earth. The 4.6 m long Advanced Light Source (ALS) undulators use flux shunts to reduce this effect. These flux shunts are magnetic linkages of very high permeability material connecting the two steel beams that support the magnetic structures. The shunts reduce the scalar potential difference between the supporting beams and carry substantial flux that would normally appear in the undulator gap. Magnetic design, mechanical configuration of the flux shunts and magnetic measurements of their effect on the ALS undulators are described

Arterioportal shunts on dynamic computed tomography

International Nuclear Information System (INIS)

Nakayama, T.; Hiyama, Y.; Ohnishi, K.; Tsuchiya, S.; Kohno, K.; Nakajima, Y.; Okuda, K.

1983-01-01

Thirty-two patients, 20 with hepatocelluar carcinoma and 12 with liver cirrhosis, were examined by dynamic computed tomography (CT) using intravenous bolus injection of contrast medium and by celiac angiography. Dynamic CT disclosed arterioportal shunting in four cases of hepatocellular carcinoma and in one of cirrhosis. In three of the former, the arterioportal shunt was adjacent to a mass lesion on CT, suggesting tumor invasion into the portal branch. In one with hepatocellular carcinoma, the shunt was remote from the mass. In the case with cirrhosis, there was no mass. In these last two cases, the shunt might have been caused by prior percutaneous needle puncture. In another case of hepatocellular carcinoma, celiac angiography but not CT demonstrated an arterioportal shunt. Thus, dynamic CT was diagnostic in five of six cases of arteriographically demonstrated arterioportal shunts

Research progress in TIPS shunt dysfunction and recanalization

Directory of Open Access Journals (Sweden)

WANG Tingting

2015-11-01

Full Text Available Transjugular intrahepatic portosystemic shunt (TIPS is widely used in the treatment of cirrhotic portal hypertension and its associated complications. However, postoperative shunt dysfunction has been an important factor restricting the clinical application of TIPS. This article summarizes the use of shunt, the incidence of shunt dysfunction after TIPS, preventive measures and diagnostic methods for shunt dysfunction, and indications and techniques of shunt recanalization, in order to enhance our knowledge of shunt dysfunction and recanalization, which could further improve the efficacy of TIPS for cirrhotic portal hypertension.

Aqueous shunt implantation in glaucoma

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Jing Wang

2017-01-01

Full Text Available Aqueous shunts or glaucoma drainage devices are increasingly utilized in the management of refractory glaucoma. The general design of the most commonly-used shunts is based on the principles of the Molteno implant: ie. a permanent sclerostomy (tube, a predetermined bleb area (plate and diversion of aqueous humour to the equatorial region and away from the limbal subconjunctival space. These three factors make aqueous shunts more resistant to scarring as compared to trabeculectomy. The two most commonly used shunts are the Ahmed Glaucoma Valve, which contains a flow-restrictor, and the non-valved Baervedlt Glaucoma Implant. While the valved implants have a lower tendency to hypotony and related complications, the non-valved implants with larger, more-biocompatible end plate design, achieve lower intraocular pressures with less encapsulation. Non-valved implants require additional suturing techniques to prevent early hypotony and a number of these methods will be described. Although serious shunt-related infection is rare, corneal decompensation and diplopia are small but significant risks.

Subgaleo-peritoneal shunt: An effective and safer alternative to lumboperitoneal shunt in the management of persistent or recurrent iatrogenic cranial pseudomeningoceles.

Science.gov (United States)

Kiran, Narayanam Anantha Sai; Thakar, Sumit; Mohan, Dilip; Aryan, Saritha; Rao, Arun Sadashiva; Hegde, Alangar S

2013-01-01

Subgaleo-peritoneal (SP) shunting for pseudomeningoceles (PMCs) is an effective and safer alternative as compared to the lumboperitoneal (LP) shunt. SP shunting was done in six patients (14-60 years) with persistent or recurrent PMCs using the cranial (ventricular part) and the distal parts of a Chhabra shunt connected by a rigid connector without any intervening chamber or valve. Two patients had undergone a prior LP shunt that had failed. One patient was unsuitable for a LP shunt placement. The PMC subsided completely in all the patients following the SP shunt. In one patient, the shunt got displaced and required repositioning. None of the patients developed symptoms of over-drainage or any other complication. All patients were asymptomatic at a mean follow-up of 15 months. These results suggest that SP shunting is a safe, simple, and effective alternative to the traditional LP shunt in the management of persistent or recurrent cranial PMCs.

Intervention on Surgical Systemic-to-Pulmonary Artery Shunts: Carotid Versus Femoral Access.

Science.gov (United States)

Ligon, R Allen; Ooi, Yinn K; Kim, Dennis W; Vincent, Robert N; Petit, Christopher J

2017-09-11

The purpose of this study was to compare results between the femoral arterial (FA) and carotid arterial (CA) approaches in catheter-based interventions on Blalock-Taussig shunts (BTS). Transcatheter intervention on BTS is often performed in shunt-dependent, hypoxemic infants. The approach to BTS intervention likely has an impact on timeliness and overall success. The authors reviewed all cases of catheter intervention for BTS obstruction between 2012 and 2017 for their institution. They sought to compare procedural success rates and time, sheath time, time to arterial access, and time from access to stent implantation between FA and CA approaches. There were 42 BTS interventions between 34 patients. BTS intervention was more successful from the CA approach (p = 0.035). Among the FA cohort, BTS intervention was unsuccessful in 8 cases (25%), 5 of which were converted to CA with subsequent success. The CA cohort had lower procedure time (62 min vs. 104 min; p = 0.01) and anesthesia time (119 min vs. 151 min; p = 0.01). Additionally, CA access was associated with shorter time to arterial access (4.0 min vs. 9.3 min; p BTS (6.5 min vs. 13 min; p BTS stent implantation (9 min vs. 20 min; p BTS deliberately. The authors' approach has been the carotid artery as an alternative access site-associated with greater procedural success, shorter procedural time, and shorter time to stent implantation. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Quadrupole shunt experiments at SPEAR

International Nuclear Information System (INIS)

Corbett, W.J.; Hettel, R.O.; Nuhn, H.-D.

1996-05-01

As part of a program to align and stabilize the SPEAR storage ring, a switchable shunt resistor was installed on each quadrupole to bypass a small percentage of the magnet current. The impact of a quadrupole shunt is to move the electron beam orbit in proportion to the off-axis beam position at the quadrupole, and to shift the betatron tune. Initially, quadrupole shunts in SPEAR were used to position the electron beam in the center of the quadrupoles. This provided readback offsets for nearby beam position monitors, and helped to steer the photon beams with low-amplitude corrector currents. The shunt-induced tune shift measurements were then processed in MAD to derive a lattice model

Rare malformation of glans penis: arteriovenous malformation.

Science.gov (United States)

Akin, Y; Sarac, M; Yucel, S

2013-01-01

Pediatric glans penis malformations, especially arteriovenous malformations (AVM), are very rare. Herein, we report two rare cases. A 14-year-old boy attended our outpatient clinic with chief complaints of purple swelling and rapidly growing lesion on the glans penis. The lesion was excised surgically after physical and radiological evaluations. Pathology reported AVM and the patient is being followed up. The second case is a 2-year-old boy who was admitted with a big lesion involving glans penis and genital area that has been present since birth. In physical and radiological evaluations, lesion on the glans penis was pulsatile. Parents of the patient did not want any surgery and patient has been in follow-up. Diagnosis of the vascular lesions on glans penis is very easy by physical and radiological examinations today. Long-term follow-up is very important for AVM. Clinicians must make a careful effort to document new glans lesions in the pediatric population and decrease anxiety in the parents of affected children.

Transcatheter coil embolisation of pulmonary arteriovenous malformations

International Nuclear Information System (INIS)

Wingen, M.; Guenther, R.W.

2001-01-01

Evaluation of technical success, complications and long-term results of transcatheter coil embolisation in pulmonary arteriovenous malformations (pAVMs). Material and Methods: Transcatheter embolisations of 46 pAVMs in 14 patients were analysed retrospectively, and, 5 years after treatment, the patients were interviewed by telefone concerning persistent symptoms and complications. Main symptoms before embolisation were dyspnoe (86%), hypoxaemia (100%), cerebral ischemia (21%), and hemoptysis (14%); 11 patients (79%) suffered from hereditary hemorrhagic telangiectasia. Results: Embolisation with an average of 3,9 coils (min. 1, max. 19 coils) per pAVM yielded technical success in all cases. Only two minor complications, transitory pleuritis and a small lung infarction were observed. On follow up examination after 5 years either no residual complaints or substantial improvement of dyspnoe were reported; no patient suffered from neurologic or hemorrhagic complications after the embolisation. Conclusion: Transcatheter embolisation is a safe and minimally invasive therapy for pAVMs and has rightfully replaced surgical resection as the therapy of choice. (orig.) [de

Pediatric ventriculoperitoneal shunts and their complications: An analysis

Directory of Open Access Journals (Sweden)

Nitin Agarwal

2017-01-01

Conclusion: With this retrospective review of complications of VP shunts, age at initial shunt insertion and the interval between the age of initial shunt placement and onset of complications were the most important patient-related predictors of shunt failure. The different predominant etiological factors responsible for early and late shunt failure were infective and mechanical complications, respectively.

Anaesthetic management of a child with massive extracranial arteriovenous malformation

Directory of Open Access Journals (Sweden)

Faisal Shamim

2012-01-01

Full Text Available Vascular tumors affect the head and neck commonly but arteriovenous malformations are rare. Vascular malformations are often present at birth and grow with the patient, usually only becoming significant later in childhood. Embolization has been the mainstay of treatment in massive and complex arteriovenous malformations. We present a case of massive extracranial arteriovenous malformation in a 7-year-old boy causing significant workload on right heart and respiratory distress. The management of angioembolization under general anaesthesia and anaesthetic concerns are presented.

Superconducting fault current-limiter with variable shunt impedance

Science.gov (United States)

Llambes, Juan Carlos H; Xiong, Xuming

2013-11-19

A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance. The second impedance of the variable-impedance shunt(s) is a lower impedance than the first impedance, which facilitates current flow through the variable-impedance shunt(s) during a recovery transition of the superconducting element from the normal resistive state to the superconducting state, and thus, facilitates recovery of the superconducting element under load.

Plain radiographic, nuclear medicine and angiographic observations of hepatogenic pulmonary angiodysplasia

Energy Technology Data Exchange (ETDEWEB)

Sang Oh, K; Bender, T M; Bowen, A D; Ledesma-Medina, J

1983-05-01

Clinical and radiological findings of hepatogenic pulmonary angiodysplasia are reported in two cases. Myriad spidery pulmonary blood vessles are seen on plain radiographs and verified with right to left intrapulmonary shunting on pulmonary angiogram and pulmonary isotopic perfusion scan. Pathophysiology and differential diagnosis are discussed. We propose the medical term ''pulmonary angiodysplasia'' to include: 1) Pulmonary telangiectasia 2) Hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber syndrome) 3) Classical discrete pulmonary arteriovenous fistula 4) Hepatogenic discrete pulmonary angiodysplasia: pulmonary arteriovenous communications with right to left shunting secondary to hepatic cirrhosis.

Idiopathic intracranial hypertension: lumboperitoneal shunts versus ventriculoperitoneal shunts--case series and literature review.

LENUS (Irish Health Repository)

Abubaker, Khalid

2011-02-01

Idiopathic intracranial hypertension (IIH) is an uncommon but important cause of headache that can lead to visual loss. This study was undertaken to review our experience in the treatment of IIH by neuronavigation-assisted ventriculoperitoneal (VP) shunts with programmable valves as compared to lumboperitoneal (LP) shunts.

Mandibular Arteriovenous Malformation in an 8-year-old Child: A Case Report.

Science.gov (United States)

Rudagi, B M; Patil, Sudha; Hammannavar, Reshma; Jaiswal, Tejus

2016-01-01

Arteriovenous (AV) malformation is a congenital vascular anomaly in which there is an abnormal connection between the arterial and venous system resulting from developmental arrest during embryogenesis. In children, they are rare and potentially life-threatening. In the present case, an 8-year-old male patient presented with a simple gingival swelling associated with mobility of the corresponding teeth, which appeared relatively simple to excise but had an AV malformation associated with it. Timely diagnosis and investigations revealed its presence and hence prevented a catastrophy from occurring. Conventional method of surgical ligation of the external carotid artery was done as an emergency procedure and surgical resection was done without compromising the associated anatomic structures. This procedure helped control the bleeding as well as achieved an uneventful healing. This case report intends to create an awareness among Pediatric Dentists regarding the condition and thereby preventing an uncontrolled and unmanageable hemorrhage occurring in the Dental Office.

Physical examination of the hemodialysis arteriovenous fistula to detect early dysfunction.

Science.gov (United States)

Abreo, Kenneth; Amin, Bakhtiar M; Abreo, Adrian P

2018-04-01

The maintenance of vascular access patency for end-stage renal disease patients on hemodialysis is necessary for survival. Many nephrologists, nurse practitioners, and nurses have limited experience with the physical examination of the arteriovenous fistula. In this review, we define key terms used in the assessment of an arteriovenous fistula. We discuss the arteriovenous fistula physical exam, including details of inspection, palpation, and auscultation. Using these concepts, we review the abnormal findings that can assist practitioners in determining the location of a stenosis. We review the existing literature that validates physical exam findings with gold standard tests such as ultrasound and angiography. Finally, we review data supporting the value of training physicians and nurses in arteriovenous fistula physical examination.

Transarterial embolization for hematuria caused by renal arteriovenous malformations or fistulae

International Nuclear Information System (INIS)

Meng Xiaoxi; Liu Shiyuan; Dong Weihua; Dong Sheng; Jia Ningyang; Xiao Xiangsheng

2008-01-01

Objective: To evaluate the efficacy and safety of transarterial embolization for hematuria caused by renal arteriovenous malformation or fistulae. Methods: Seven patients with gross hematuria caused by renal arterial abnormalities were retrospectively reviewed, of which three had congenital renal arteriovenous malformations and the other four had non-neoplastic acquired renal arteriovenous fistulae. All patients were confirmed by renal arterial angiography and undergone embolization with various embolic materials. Results: Embolization was successfully carried out in all cases. Gross hematuria disappeared one to seven days after the procedure. No severe complications were encountered. No recurrence occurred within 12 to 36 months of follow-up. Conclusions: Transarterial embolization is safe and effective for hematuria caused by renal arteriovenous malformations or fistulae. (authors)

Quadrupole shunt experiments at SPEAR

International Nuclear Information System (INIS)

Corbett, W.J.; Hettel, R.O.; Nuhn, H.

1997-01-01

As part of a program to align and stabilize the SPEAR storage ring, a switchable shunt resistor was installed on each quadrupole to bypass a small percentage of the magnet current. The impact of a quadrupole shunt is to move the electron beam orbit in proportion to the off-axis beam position at the quadrupole and to shift the betatron tune. Initially, quadrupole shunts in SPEAR were used to position the electron beam in the center of the quadrupoles. This provided readback offsets for nearby beam position monitors and helped to steer the photon beams with low-amplitude corrector currents. The shunt-induced tune shift measurements were then processed in MAD to derive a lattice model. copyright 1997 American Institute of Physics

Initial shunt type at the Norwood operation impacts myocardial function in hypoplastic left heart syndrome.

Science.gov (United States)

Ruotsalainen, Hanna K; Pihkala, Jaana; Salminen, Jukka; Hornberger, Lisa K; Sairanen, Heikki; Ojala, Tiina

2017-08-01

We investigated the impact of initial shunt type, a Blalock-Taussig (BT) shunt versus a right ventricle to pulmonary artery conduit (RV-PA) on myocardial function at different stages of surgical palliation in patients with hypoplastic left heart syndrome (HLHS). A population-based cohort of 63 Finnish children with HLHS (BT n  = 23, RV-PA n  = 40) born between 2003 and 2010 were studied retrospectively by echocardiography prior to Stages 1, 2 and 3 palliation and 0.5-3 years after Stage 3. For comparison of systolic myocardial function, we evaluated the RV fractional area change (FAC), strain, strain rate and mechanical synchrony from the apical 4-chamber view by velocity vector imaging. There were no intergroup differences in demographics during the study period. At baseline, no intergroup differences were detected in RV systolic myocardial function. Before Stage 2, RV FAC was higher ( P  = 0.03) in the RV-PA conduit group. At Stage 3, an increase in all systolic myocardial functional parameters was observed in the BT shunt group. After Stage 3, the BT shunt group had better RV systolic function. In multiple regression analysis, the shunt type and the stage of palliation had an impact on myocardial function. Although patients with HLHS initially palliated with a BT shunt demonstrate lower RV FAC after Stage I, RV FAC improves after Stage 2 with better systolic performance after Stage 3 compared with those initially palliated with an RV-PA conduit. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Migration of a ventriculo-peritoneal shunt catheter into a back incision of a patient with previous spinal fusion.

Science.gov (United States)

Suryadevara, Raviteja; Lieber, Bryan A; Garcia, Erick; Sood, Sandeep; Haridas, Abilash; Ham, Steven

2018-04-01

This case examines a unique, longitudinal presentation of an abandoned, migrating VP shunt which presents as multiple complications, including a weeping abscess in the patients back. We believe that the latter complication was potentially caused by the wound from the patient's previous history of spinal fusion surgery. The patient presents with an associated type 2 Chiari malformation, hydrocephalus, and a previous history of posterior spinal fusion (T4-L5 anterior fusion and T2-L5 posterior fusion) at age 11. The patient had undergone shunt revisions in early adolescence as well. At 22, the patient is admitted into emergency care due to recurrent infections caused by a migrating VP shunt. Due to complications in corrective surgery at the time, the shunt was forced to be abandoned. This resulted in the most recent presentation of a weeping abscess at the patient's spinal fusion surgery wound; the culprit was the abandoned, migrating VP shunt.. An initial course of broad-spectrum antibiotics was started. However, the abscess continued to recur. Eventually, the catheter was surgically removed, a tailored antibiotic regiment was started, and a 6-month patient follow-up was performed. The patient is no longer symptomatic and off of antibiotics. In abandoned VP shunts, migration into a non-sterile cavity dictates prompt removal, especially after symptoms of infection present. Additionally, careful monitoring for signs of peritonitis or other symptoms for a dedicated period of time is necessary. To the authors' best knowledge, this is the first case of an occult shunt migration through the patient's back that presented with a weeping abscess.

A wireless monitoring system for Hydrocephalus shunts.

Science.gov (United States)

Narayanaswamy, A; Nourani, M; Tamil, L; Bianco, S

2015-08-01

Patients with Hydrocephalus are usually treated by diverting the excess Cerebrospinal Fluid (CSF) to other parts of the body using shunts. More than 40 percentage of shunts implanted fail within the first two years. Obstruction in the shunts is one of the major causes of failure (45 percent) and the detection of obstruction reduces the complexity of the revision surgery. This paper describes a proposed wireless monitoring system for clog detection and flow measurement in shunts. A prototype was built using multiple pressure sensors along the shunt catheters for sensing the location of clog and flow rate. Regular monitoring of flow rates can be used to adjust the valve in the shunt to prevent over drainage or under drainage of CSF. The accuracy of the flow measurement is more than 90 percent.

Stent graft placement for dysfunctional arteriovenous grafts

Energy Technology Data Exchange (ETDEWEB)

Jeon, Gyeong Sik [Dept. of Radiology, CHA Bundang Medical Center, College of Medicine, CHA University, Seongnam (Korea, Republic of); Shin, Byung Seok; Ohm, Joon Young; Ahn, Moon Sang [Chungnam National University Hospital, Daejeon (Korea, Republic of)

2015-07-15

This study aimed to evaluate the usefulness and outcomes of stent graft use in dysfunctional arteriovenous grafts. Eleven patients who underwent stent graft placement for a dysfunctional hemodialysis graft were included in this retrospective study. Expanded polytetrafluoroethylene covered stent grafts were placed at the venous anastomosis site in case of pseudoaneurysm, venous laceration, elastic recoil or residual restenosis despite the repeated angioplasty. The patency of the arteriovenous graft was evaluated using Kaplan-Meier analysis. Primary and secondary mean patency was 363 days and 741 days. Primary patency at 3, 6, and 12 months was 82%, 73%, and 32%, respectively. Secondary patency at the 3, 6, 12, 24, and 36 months was improved to 91%, 82%, 82%, 50%, and 25%, respectively. Fractures of the stent graft were observed in 2 patients, but had no effect on the patency. Stent graft placement in dysfunctional arteriovenous graft is useful and effective in prolonging graft patency.

Predictive simulation of bidirectional Glenn shunt using a hybrid blood vessel model.

Science.gov (United States)

Li, Hao; Leow, Wee Kheng; Chiu, Ing-Sh

2009-01-01

This paper proposes a method for performing predictive simulation of cardiac surgery. It applies a hybrid approach to model the deformation of blood vessels. The hybrid blood vessel model consists of a reference Cosserat rod and a surface mesh. The reference Cosserat rod models the blood vessel's global bending, stretching, twisting and shearing in a physically correct manner, and the surface mesh models the surface details of the blood vessel. In this way, the deformation of blood vessels can be computed efficiently and accurately. Our predictive simulation system can produce complex surgical results given a small amount of user inputs. It allows the surgeon to easily explore various surgical options and evaluate them. Tests of the system using bidirectional Glenn shunt (BDG) as an application example show that the results produc by the system are similar to real surgical results.

Hydrocephalus shunt technology: 20 years of experience from the Cambridge Shunt Evaluation Laboratory.

Science.gov (United States)

Chari, Aswin; Czosnyka, Marek; Richards, Hugh K; Pickard, John D; Czosnyka, Zofia H

2014-03-01

The Cambridge Shunt Evaluation Laboratory was established 20 years ago. This paper summarizes the findings of that laboratory for the clinician. Twenty-six models of valves have been tested long-term in the shunt laboratory according to the expanded International Organization for Standardization 7197 standard protocol. The majority of the valves had a nonphysiologically low hydrodynamic resistance (from 1.5 to 3 mm Hg/[ml/min]), which may result in overdrainage related to posture and during nocturnal cerebral vasogenic waves. A long distal catheter increases the resistance of these valves by 100%-200%. Drainage through valves without a siphon-preventing mechanism is very sensitive to body posture, which may result in grossly negative intracranial pressure. Siphon-preventing accessories offer a reasonable resistance to negative outlet pressure; however, accessories with membrane devices may be blocked by raised subcutaneous pressure. In adjustable valves, the settings may be changed by external magnetic fields of intensity above 40 mT (exceptions: ProGAV, Polaris, and Certas). Most of the magnetically adjustable valves produce large distortions on MRI studies. The behavior of a valve revealed during testing is of relevance to the surgeon and may not be adequately described in the manufacturer's product information. The results of shunt testing are helpful in many circumstances, such as the initial choice of shunt and the evaluation of the shunt when its dysfunction is suspected.

Transcatheter arterial ethanol embolization for congenital renal arteriovenous malformations

International Nuclear Information System (INIS)

Wang Jingbing; Wang Han; An Xiao; Wang Linchuan; Gao Liqiang; Zhou Zhiguo; Zhang Guixiang

2010-01-01

Objective: To discuss the effect and safety of trans-microcatheter arterial embolization with ethanol for the treatment of congenital renal arteriovenous malformations. Methods: Clinical data of 11 patients with congenital renal arteriovenous malformations manifested mainly as gross hematuria were retrospectively analyzed. Selective renal angiography was performed in all 11 patients. After the diagnosis was confirmed, super-selective catheterization of the diseased arteries was carried out and the trans-microcatheter arterial embolization with ethanol was conducted. Results: A total of 12 procedures were completed in 11 patients. The ethanol dose used in one procedure was 5-25 ml. Successful embolization of the congenital renal arteriovenous malformations was obtained in all patients. The gross hematuria disappeared within 24-48 hours after the treatment. Lumbago at treated side, low fever, abdominal distension, nausea, vomiting, etc. occurred within one week and no other serious complications developed. During the follow-up period lasting for 4-96 months, no recurrence of hematuria was observed and the renal function remained normal. Conclusion: Transcatheter arterial ethanol embolization is an economic, safe and effective treatment for congenital renal arteriovenous malformations. (authors)

Congenital portosystemic shunts with and without gastrointestinal bleeding - case series

Energy Technology Data Exchange (ETDEWEB)

Gong, Ying; Chen, Jun; Chen, Qi; Ji, Min; Pa, Mier; Qiao, Zhongwei [Children' s Hospital of Fudan University, Department of Radiology, Shanghai (China); Zhu, Hui [Fudan University Shanghai Cancer Center, Department of Radiology, Shanghai (China); Zheng, Shan [Children' s Hospital of Fudan University, Department of Surgery, Shanghai (China)

2015-12-15

The clinical presentation of congenital portosystemic shunt is variable and gastrointestinal bleeding is an uncommon presentation. To describe the imaging features of congenital portosystemic shunt as it presented in 11 children with (n = 6) and without gastrointestinal bleeding (n = 5). We performed a retrospective study on a clinical and imaging dataset of 11 children diagnosed with congenital portosystemic shunt. A total of 11 children with congenital portosystemic shunt were included in this study, 7 with extrahepatic portosystemic shunts and 4 with intrahepatic portosystemic shunts. Six patients with gastrointestinal bleeding had an extrahepatic portosystemic shunt, and the imaging results showed that the shunts originated from the splenomesenteric junction (n = 5) or splenic vein (n = 1) and connected to the internal iliac vein. Among the five cases of congenital portosystemic shunt without gastrointestinal bleeding, one case was an extrahepatic portosystemic shunt and the other four were intrahepatic portosystemic shunts. Most congenital portosystemic shunt patients with gastrointestinal bleeding had a shunt that drained portal blood into the iliac vein via an inferior mesenteric vein. This type of shunt was uncommon, but the concomitant rate of gastrointestinal bleeding with this type of shunt was high. (orig.)

[Brachial artery pseudoaneurysm: a rare but serious complication in hemodialysis patients with arteriovenous fistula].

Science.gov (United States)

Mancini, Andrea; Castriotta, Giuseppe; Angelini, Pernina; Bozzi, Michele; Giancaspro, Vincenzo; La Raia, Elvira; Nisi, Maria Teresa; Proscia, Anna Rita; Tarantino, Giuseppe; Vitale, Ottavia; Cuzzola, Cristoforo

2017-06-01

A pseudoaneurysm or false aneurysm of the brachial artery is an uncommon occurrence in patients receiving hemodialysis with arteriovenous fistula (AVF). We describe the case of a 76-year-old woman presenting with a large, tender, pulsatile mass in the right antecubital region 10 cm from the AVF. B-mode ultrasound examination revealed a saccular hematoma. Color doppler showed a recirculation movement of blood, creating a two colors image called "Korean flag". The patient was transferred to the surgical unit where she first underwent ultrasound-guided compression and then surgical repair of the pseudoaneurysm. Two weeks after surgery the AVF was used again as an access for hemodialysis. Differentiating between a false and a true aneurysm based on ultrasound is not always straightforward. Doppler ultrasound findings can be decisive for the early diagnosis of a pseudoaneurysm to ensure proper treatment planning given the dangerous complications of ruptures. Treatment options include: compression, percutaneous thrombin injection, endovascular exclusion with covered stents, aneurysmectomy and surgical repair. Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.

MR-angiogram-added surface anatomy scanning of superficial cerebral arteriovenous malformations

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, Kazuhiro; Katase, Shichiro; Yoshino, Ayako; Hachiya, Junichi [Department of Radiology, Kyorin University School of Medicine, 6-20-2, Shinkawa, Mitaka, Tokyo 181-8611 (Japan); Shiokawa, Yoshiaki [Department of Neurosurgery, Kyorin University School of Medicine, 6-20-2, Shinkawa, Mitaka, Tokyo 181-8611 (Japan)

2002-09-01

Our purpose was to evaluate the utility of surface anatomy scanning (SAS) of the brain with superimposition of MR angiograms in the diagnosis and presurgical planning of superficial cerebral arteriovenous malformations (AVMs). We performed SAS in 15 patients with superficial cerebral AVMs. Two-dimensional phase-contrast MR angiograms were then obtained in the same section and superimposed on the SAS images. The images were assessed regarding the visualization of each AVM component using a four-point grading scale (3=excellent to 0=poor). In 13 of the patients, the assessment was made comparing with conventional angiograms. The images were also compared with the surgical findings in 5 patients. The added images agreed well with the angiographic findings and demonstrated the relationships between the AVM components and the adjacent brain surface. The average scores of the feeder(s), nidus, and drainer(s) were 2.27, 2.33, and 2.67, respectively. The surgical findings also correlated well with the added images. Our technique can noninvasively demonstrate superficial AVMs along with the brain surface and provide information useful for planning surgery. (orig.)

MR-angiogram-added surface anatomy scanning of superficial cerebral arteriovenous malformations

International Nuclear Information System (INIS)

Tsuchiya, Kazuhiro; Katase, Shichiro; Yoshino, Ayako; Hachiya, Junichi; Shiokawa, Yoshiaki

2002-01-01

Our purpose was to evaluate the utility of surface anatomy scanning (SAS) of the brain with superimposition of MR angiograms in the diagnosis and presurgical planning of superficial cerebral arteriovenous malformations (AVMs). We performed SAS in 15 patients with superficial cerebral AVMs. Two-dimensional phase-contrast MR angiograms were then obtained in the same section and superimposed on the SAS images. The images were assessed regarding the visualization of each AVM component using a four-point grading scale (3=excellent to 0=poor). In 13 of the patients, the assessment was made comparing with conventional angiograms. The images were also compared with the surgical findings in 5 patients. The added images agreed well with the angiographic findings and demonstrated the relationships between the AVM components and the adjacent brain surface. The average scores of the feeder(s), nidus, and drainer(s) were 2.27, 2.33, and 2.67, respectively. The surgical findings also correlated well with the added images. Our technique can noninvasively demonstrate superficial AVMs along with the brain surface and provide information useful for planning surgery. (orig.)

Transcatheter arterial embolization for congenital renal arteriovenous malformation

International Nuclear Information System (INIS)

Zhou Jun; Hu Tingyang; Yuan Jianhua; Yu Wenqiang

2008-01-01

Objective: To evaluate the effectiveness of transcatheter arterial embolization for congenital renal arteriovenous malformation. Methods: Seven cases of congenital renal arteriovenous malformation causing gross hematuria were retrospectively studied. All of 7 cases were demonstrated by means of angiography and then the catheter was placed superselectively into the involved arterial end of the malformation undertaking embolization with gelfoam, dehydrated ethanol, coils, etc. Results: All the malformations of the 7 cases were successfully embolized with stoppage of gross hematuria within 24 hours. No serious complications occurred except lumbago, fever, gastrointestinal reaction for one week. There was no recurrence of haematuria and the renal function was also normal in all cases during the follow-up for 36 to 98 months. Conclusions: Transcatheter renal arterial angiography and embolization are the important and effective management for the diagnosis and treatment of congenital renal arteriovenous malformation. (authors)

Direct Puncture Embolization of Scalp Arteriovenous Malformation in a Patient with Severe Hemophilia A: A Case Report

International Nuclear Information System (INIS)

Lee, Kyung Mi; Kim, Eui Jong; Park, Bong Jin; Kim, Keon Ha

2011-01-01

We present a case of scalp arteriovenous malformation (AVM) in a patient with severe hemophilia A. The 22-year-old man presented with a pulsatile right parietal scalp mass. Digital subtraction angiography revealed an AVM in the right parietal scalp, supplied by superficial temporal and occipital arteries that drained into multiple venous structures. We successfully performed direct puncture embolization followed by surgical resection of the scalp AVM in conjunction with supplemental infusion of coagulation factor VIII before, during and after the embolization and the operation.

Direct Puncture Embolization of Scalp Arteriovenous Malformation in a Patient with Severe Hemophilia A: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyung Mi; Kim, Eui Jong [Dept. of Radiology, Kyung Hee University Hospital, Kyung Hee University Graduate School of Medicine, Seoul (Korea, Republic of); Park, Bong Jin [Dept. of Neurosurgery, Kyung Hee University Hospital, Kyung Hee University Graduate School of Medicine, Seoul (Korea, Republic of); Kim, Keon Ha [Dept. of Radiology, Samsug Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2011-09-15

We present a case of scalp arteriovenous malformation (AVM) in a patient with severe hemophilia A. The 22-year-old man presented with a pulsatile right parietal scalp mass. Digital subtraction angiography revealed an AVM in the right parietal scalp, supplied by superficial temporal and occipital arteries that drained into multiple venous structures. We successfully performed direct puncture embolization followed by surgical resection of the scalp AVM in conjunction with supplemental infusion of coagulation factor VIII before, during and after the embolization and the operation.

Quality measurement in the shunt treatment of hydrocephalus: analysis and risk adjustment of the Revision Quotient.

Science.gov (United States)

Piatt, Joseph H; Freibott, Christina E

2014-07-01

OBJECT.: The Revision Quotient (RQ) has been defined as the ratio of the number of CSF shunt revisions to the number of new shunt insertions for a particular neurosurgical practice in a unit of time. The RQ has been proposed as a quality measure in the treatment of childhood hydrocephalus. The authors examined the construct validity of the RQ and explored the feasibility of risk stratification under this metric. The Kids' Inpatient Database for 1997, 2000, 2003, 2006, and 2009 was queried for admissions with diagnostic codes for hydrocephalus and procedural codes for CSF shunt insertion or revision. Revision quotients were calculated for hospitals that performed 12 or more shunt insertions annually. The univariate associations of hospital RQs with a variety of institutional descriptors were analyzed, and a generalized linear model of the RQ was constructed. There were 12,244 admissions (34%) during which new shunts were inserted, and there were 23,349 admissions (66%) for shunt revision. Three hundred thirty-four annual RQs were calculated for 152 different hospitals. Analysis of variance in hospital RQs over the 5 years of study data supports the construct validity of the metric. The following factors were incorporated into a generalized linear model that accounted for 41% of the variance of the measured RQs: degree of pediatric specialization, proportion of initial case mix in the infant age group, and proportion with neoplastic hydrocephalus. The RQ has construct validity. Risk adjustment is feasible, but the risk factors that were identified relate predominantly to patterns of patient flow through the health care system. Possible advantages of an alternative metric, the Surgical Activity Ratio, are discussed.

A Case of Shunting Postoperative Patent Foramen Ovale Under Mechanical Ventilation Controlled by Different Ventilator Settings.

Science.gov (United States)

Pragliola, Claudio; Di Michele, Sara; Galzerano, Domenico

2017-06-07

A 56-year old male with ischemic heart disease and an unremarkable preoperative echocardiogram underwent surgical coronary revascularization. An intraoperative post pump trans-esophageal echocardiogram (TOE) performed while the patient was being ventilated at a positive end expiratory pressure (PEEP) of 8 cm H 2 O demonstrated a right to left interatrial shunt across a patent foramen ovale (PFO). Whereas oxygen saturation was normal, a reduction of the PEEP to 3 cm H 2 O led to the complete resolution of the shunt with no change in arterial blood gases. Attempts to increase the PEEP level above 3 mmHg resulted in recurrence of the interatrial shunt. The remaining of the TEE was unremarkable. Mechanical ventilation, particularly with PEEP, causes an increase in intrathoracic pressure. The resulting rise in right atrial pressure, mostly during inspiration, may unveil and pop open an unrecognized PFO, thus provoking a right to left shunt across a seemingly intact interatrial septum. This phenomenon increases the risk of paradoxical embolism and can lead to hypoxemia. The immediate management would be to adjust the ventilatory settings to a lower PEEP level. A routine search for a PFO should be performed in ventilated patients who undergo a TEE.

A case of shunting postoperative patent foramen ovale under mechanical ventilation controlled by different ventilator settings

Directory of Open Access Journals (Sweden)

Claudio Pragliola

2017-08-01

Full Text Available A 56-year old male with ischemic heart disease and an unremarkable preoperative echocardiogram underwent surgical coronary revascularization. An intraoperative post pump trans-esophageal echocardiogram (TOE performed while the patient was being ventilated at a positive end expiratory pressure (PEEP of 8 cm H2O demonstrated a right to left interatrial shunt across a patent foramen ovale (PFO. Whereas oxygen saturation was normal, a reduction of the PEEP to 3 cm H2O led to the complete resolution of the shunt with no change in arterial blood gases. Attempts to increase the PEEP level above 3 mmHg resulted in recurrence of the interatrial shunt. The remaining of the TEE was unremarkable. Mechanical ventilation, particularly with PEEP, causes an increase in intrathoracic pressure. The resulting rise in right atrial pressure, mostly during inspiration, may unveil and pop open an unrecognized PFO, thus provoking a right to left shunt across a seemingly intact interatrial septum. This phenomenon increases the risk of paradoxical embolism and can lead to hypoxemia. The immediate management would be to adjust the ventilatory settings to a lower PEEP level. A routine search for a PFO should be performed in ventilated patients who undergo a TEE.

Ventriculosubgaleal shunts for posthemorrhagic hydrocephalus in premature infants.

Science.gov (United States)

Willis, Brian K; Kumar, Cherukuri Ravi; Wylen, Esther L; Nanda, Anil

2005-01-01

The early management of posthemorrhagic hydrocephalus in premature infants is challenging and controversial. These infants need a temporary cerebrospinal fluid (CSF) diversion procedure until they gain adequate weight, and the blood and protein levels in CSF are reasonably low before permanent shunt can be placed. Various options are available with their associated advantages and disadvantages. Ventriculosubgaleal shunts have been recommended as a more physiologic and less invasive means of achieving this goal. We have performed this procedure in 6 premature infants to evaluate their effectiveness and complications. Six consecutive premature infants with posthemorrhagic hydrocephalus underwent placement of ventriculosubgaleal shunts over a 1-year period of time. We reviewed their clinical and imaging progress to assess the ability of the shunt to control hydrocephalus and the complication rates. In all 6 patients, the ventriculosubgaleal shunt controlled the progression of hydrocephalus as assessed by clinical and imaging parameters. A permanent shunt was avoided in 1 patient (16.6%). However, 4 patients developed shunt infections, 1 involving the ventriculosubgaleal shunt itself, and 3 immediately after conversion to ventriculoperitoneal shunt. The total infection rate of the series was 66.6%. All infections were caused by staphylococcus species. There was only a 1% shunt infection rate in our institution for all nonventriculosubgaleal shunts during the same period of time. Placement of ventriculosubgaleal shunts for interim CSF diversion in neonates with posthemorrhagic hydrocephalus is effective as a temporary method of CSF diversion. However, our experience has shown that it is associated with a unacceptably high CSF infection rate. A potential cause for infection is CSF stasis just beneath the extremely thin skin of the premature infants, promoting colonization by skin flora. CSF sampling before conversion to a permanent shunt and replacement of the proximal

Cell shunt resistance and photovoltaic module performance

Energy Technology Data Exchange (ETDEWEB)

McMahon, T.J.; Basso, T.S.; Rummel, S.R. [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. The authors describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without deencapsulation. Peak power efficiency vs. light intensity was measured on a 12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, the authors verified that cell shunt and series resistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. The authors discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.

Traumatic tricuspid regurgitation and right-to-left intra-atrial shunt--an unusual complication of a horse-kick.

LENUS (Irish Health Repository)

Byrne, R A

2010-02-01

A 63-year-old male presented with sudden onset chest pain and dyspnoea following a kick to the praecordium while gelding a horse. Transthoracic echocardiography showed evidence of flail tricuspid valve leaflets, severe tricuspid regurgitation and a widely patent foramen ovale with a right-to-left shunt. Due to progressive severe systemic hypoxemia the patient underwent emergent surgical intervention. Operative findings confirmed rupture of the anterior and septal tricuspid valve papillary muscles. Successful papillary muscle reattachment was performed in association with tricuspid annuloplasty and suture closure of his patent foramen ovale. Disruption of the tricuspid valve is well described as consequence of blunt trauma to the chest wall and is often well tolerated, coming to light many years post injury. Valve disruption due to rupture at the papillary muscle level, however, typically results in greater severity of tricuspid regurgitation and the abrupt rise in right intra-atrial pressure may lead to a right-to-left shunt across a patent foramen ovale. Where hemodynamic compromise ensues, prompt surgical intervention is mandated.

Cardiac resynchronisation therapy in the presence of left-to-right intracardiac shunting: more good than harm?

Science.gov (United States)

Kyu, Kyu; Seow, Swee Chong; Wong, Raymond; Kojodjojo, Pipin

2016-03-17

An elderly Chinese man with moderately impaired left ventricular function, left bundle branch block and ST-elevation myocardial infarction complicated by ventricular septal rupture had class IV heart failure symptoms refractory to medical and surgical interventions. As a treatment of last resort, a cardiac resynchronisation therapy (CRT) pacemaker was implanted apprehensively, as preoperative concerns were raised whether CRT could exacerbate left-to-right shunting, hence negating the potential benefits of CRT. Introduction of CRT significantly improved the patient's haemodynamic status and symptoms, allowing for successful discharge home. To the best of our knowledge, this is the first report of a patient with severely symptomatic acute heart failure, widened QRS and active left-to-right intracardiac shunting, treated successfully with CRT. 2016 BMJ Publishing Group Ltd.

30 CFR 57.6401 - Shunting.

Science.gov (United States)

2010-07-01

... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Electric Blasting-Surface and Underground § 57.6401 Shunting. Except during testing— (a) Electric detonators shall be kept shunted until connected to the blasting line or wired into a blasting round; (b) Wired rounds shall be...

Histologic examination of hepatic biopsy samples as a prognostic indicator in dogs undergoing surgical correction of congenital portosystemic shunts: 64 cases (1997-2005).

Science.gov (United States)

Parker, Jacquelyn S; Monnet, Eric; Powers, Barbara E; Twedt, David C

2008-05-15

To determine whether results of histologic examination of hepatic biopsy samples could be used as an indicator of survival time in dogs that underwent surgical correction of a congenital portosystemic shunt (PSS). Retrospective case series. 64 dogs that underwent exploratory laparotomy for an extrahepatic (n = 39) or intrahepatic (25) congenital PSS. All H&E-stained histologic slides of hepatic biopsy samples obtained at the time of surgery were reviewed by a single individual, and severity of histologic abnormalities (ie, arteriolar hyperplasia, biliary hyperplasia, fibrosis, cell swelling, lipidosis, lymphoplasmacytic cholangiohepatitis, suppurative cholangiohepatitis, lipid granulomas, and dilated sinusoids) was graded. A Cox proportional hazards regression model was used to determine whether each histologic feature was associated with survival time. Median follow-up time was 35.7 months, and median survival time was 50.6 months. Thirty-eight dogs were alive at the time of final follow-up; 15 had died of causes associated with the PSS, including 4 that died immediately after surgery; 3 had died of unrelated causes; and 8 were lost to follow-up. None of the histologic features examined were significantly associated with survival time. Findings suggested that results of histologic examination of hepatic biopsy samples obtained at the time of surgery cannot be used to predict long-term outcome in dogs undergoing surgical correction of a PSS.

MR imaging of syringoperitoneal and syringosubarachnoid shunts

International Nuclear Information System (INIS)

Hasso, A.N.; Kucharczyk, W.; Mall, J.C.; Colombo, N.; Newton, T.H.; Norman, D.

1986-01-01

The authors utilized MR imaging for the evaluation of syringohydromelic shunt procedures in 16 patients. Four characteristic MR imaging findings were seen: ''tethering'' of the spinal cord posteriorly at the site of laminectomy and placement of the shunt tube distortion of the usual elliptical shape of the spinal cord at the site of the shunt, a ''snake-eyes'' appearance of the cord on transverse images which corresponded to the position of the shunt within or next to a collapsed syringohydromelic cavity, and a generous amount of subachnoid space surrounding the collapsed portion of the cavity. Occasionally the shunt could not be visualized on sagittal images but could be seen on transverse images. In the majority of cases, the MR imaging findings were sufficiently characteristic to warrant accurate diagnosis

Modern classification and outcome predictors of surgery in patients with brain arteriovenous malformations.

Science.gov (United States)

Tayebi Meybodi, Ali; Lawton, Michael T

2018-02-23

Brain arteriovenous malformations (bAVM) are challenging lesions. Part of this challenge stems from the infinite diversity of these lesions regarding shape, location, anatomy, and physiology. This diversity has called on a variety of treatment modalities for these lesions, of which microsurgical resection prevails as the mainstay of treatment. As such, outcome prediction and managing strategy mainly rely on unraveling the nature of these complex tangles and ways each lesion responds to various therapeutic modalities. This strategy needs the ability to decipher each lesion through accurate and efficient categorization. Therefore, classification schemes are essential parts of treatment planning and outcome prediction. This article summarizes different surgical classification schemes and outcome predictors proposed for bAVMs.

Occupational therapy for patients with an arterio-venous fistula

Directory of Open Access Journals (Sweden)

Iustinian BENGULESCU

2017-03-01

Full Text Available End stage renal disease (ESRD represents a chronic medical condition that has become a public health problem and requires substantial funding. The number of patients with ESRD is rapidly increasing. From the moment that ESRD is diagnosed, the natural evolution of this pathology is towards mandatory dialysis, in absence of a renal transplant procedure. In order to perform hemodialysis, a vascular access site must be created and maintained functional. A proper vascular access site allows an adequate blood flow through the dialysis machine, in order to obtain the required results. The arterio-venous fistula represents the number one recommended vascular access site procedure. Establishing and maintaining a vascular access represents one of the biggest problems in hemodialysis. The arterio-venous fistula thus becomes the patient’s lifeline. Maintaining a good quality vascular access site is a demanding process and requires cooperation between both the patient and the health care providers. For ESRD patients there is a constant concern regarding the patency of their vascular access. The aim of this paper is to present the postoperative measures that ESRD patients should provide in order to preserve their vascular access. Also, we want to present the main signs of an early complication that patients should recognize and therefore immediately present themselves to the physician. By establishing this type of cooperation and trust between the patient and the medical staff we will be able to reduce the number of surgical procedures required for the creation and maintenance of the vascular access. Our final thought remains that a well-informed patient has better chances of prolonging his “lifeline”.

Transjugular Intrahepatic Portosystemic Shunt Dysfunction: Concordance of Clinical Findings, Doppler Ultrasound Examination, and Shunt Venography.

Science.gov (United States)

Owen, Joshua M; Gaba, Ron Charles

2016-01-01

The objective of this study was to evaluate the concordance between clinical symptoms, Doppler ultrasound (US), and shunt venography for the detection of stent-graft transjugular intrahepatic portosystemic shunt (TIPS) dysfunction. Forty-one patients (M:F 30:11, median age 55 years) who underwent contemporaneous clinical exam, Doppler US, and TIPS venography between 2003 and 2014 were retrospectively studied. Clinical symptoms (recurrent ascites or variceal bleeding) were dichotomously classified as present/absent, and US and TIPS venograms were categorized in a binary fashion as normal/abnormal. US abnormalities included high/low (>190 or 50 cm/s), absent flow, and return of antegrade intra-hepatic portal flow. Venographic abnormalities included shunt stenosis/occlusion and/or pressure gradient elevation. Clinical and imaging concordance rates were calculated. Fifty-two corresponding US examinations and venograms were assessed. The median time between studies was 3 days. Forty of 52 (77%) patients were symptomatic, 33/52 (64%) US examinations were abnormal, and 20/52 (38%) TIPS venograms were abnormal. Concordance between clinical symptoms and TIPS venography was 48% (25/52), while the agreement between US and shunt venography was 65% (34/52). Clinical symptoms and the US concurred in 60% (31/52) of the patients. The sensitivity of clinical symptoms and US for the detection of venographically abnormal shunts was 80% (16/20) and 85% (17/20), respectively. Both clinical symptoms and the US had low specificity (25%, 8/32 and 50%, 16/32) for venographically abnormal shunts. Clinical findings and the US had low concordance rates with TIPS venography, with acceptable sensitivity but poor specificity. These findings suggest the need for improved noninvasive imaging methods for stent-graft TIPS surveillance.

Ventriculoperitoneal shunt infections in children

African Journals Online (AJOL)

1991-02-02

Feb 2, 1991 ... shunts: epidemiology, clinical manifestations and therapy.] Infecr Vis 1975;. 13: 543-552. 4. Odio C, McCracken GH jun, Nelson JD. CSF shunt infections in pediatrics, a seven-year experience. Am] Dis Child 1984; 138: 1103-1108. 5. Meirovitch J, Kitai-Cohen Y, Keren G, Fiendler G, Rubinstein E. Cerebro-.

Emergency hepatectomy for hepatic arteriovenous malformation combined with pulmonary hypertension in an infant

Directory of Open Access Journals (Sweden)

Naruhiko Murase

2015-12-01

Full Text Available Patients with hepatic arteriovenous malformations rarely present with pulmonary hypertension. We report the case of a 3-month-old boy who developed severe pulmonary hypertension due to a hepatic arteriovenous malformation. The use of pulmonary vasodilators to treat the patient's pulmonary hypertension worsened his high-output heart failure. This is the first case in which emergency hepatectomy rescued a patient with hepatic arteriovenous malformations who developed pulmonary hypertension.

[Paradoxical brain embolism mediated through a pulmonary arteriovenous malformation with hereditary hemorrhagic telangiectasia in a Japanese patient].

Science.gov (United States)

Takeda, June; Todo, Kenichi; Yamamoto, Shiro; Yamagami, Hiroshi; Kawamoto, Michi; Kohara, Nobuo

2012-01-01

We report a case of paradoxical brain embolism mediated through a pulmonary arteriovenous malformation (PAVM) with hereditary hemorrhagic telangiectasia (HHT). A 25-year-old right handed man was admitted to our hospital after sudden headache and visual field abnormality. In neurologic examinations, he had left superior-quadrantanopsia. Laboratory findings showed iron deficiency anemia. Diffusion weighted images disclosed a high-signal-intensity area in the right occipito-temporal lobe, and intraarterial digital subtraction cerebral angiography revealed occlusion of the right posterior cerebral artery. Transesophageal echocardiography revealed continuous right-to-left shunt. We confirmed his history of spontaneous recurrent epistaxis and the first-degree relatives with epistaxis or PAVM. A contrast enhanced CT scan of the chest revealed a PAVM. The diagnosis of paradoxical brain embolism mediated through the PAVM with HHT was, thus, established. The PAVM was occluded by using embolization coils successfully. In Asian countries, the prevalence of PAVM with HHT is thought to be lower than in European countries. We should carefully take medical and family histories, especially epistaxis, in a young stroke patient.

Endovascular treatment of a cavernous sinus dural arteriovenous fistula by transvenous embolisation through the superior ophthalmic vein via cannulation of a frontal vein

International Nuclear Information System (INIS)

Venturi, C.; Bracco, S.; Cerase, A.; Gennari, P.; Lore, F.; Polito, E.; Casasco, A.E.

2003-01-01

We describe a new approach for transvenous embolisation of cavernous sinus dural arteriovenous fistulae through the superior ophthalmic vein (SOV), i.e., via percutaneous cannulation of a frontal vein. Modern neurointerventional angiographic materials make it possible to reach the SOV in this way without puncturing it in the orbit or a surgical exposure. Orbital phlebography should still be in the repertoire of interventional neuroradiology units in large centres. (orig.)

Effects of Chronic Blood-Flow Restriction Exercise on Skeletal Muscle Size and Myogenic Satellite Cell Expression

DEFF Research Database (Denmark)

Aagaard, Per; Jacobsen, Mikkel; Jensen, Kasper Y.

2016-01-01

This single-case study examined an arterio-venous shunt patient (20 year old male) where a main artery supplying the left leg in the deeper anterior pelvis was connected to a returning vein, possibly due to previous trauma received while playing high level Team Handball. Due to this A-V shunt...

An experimental in-vivo canine model for adult shunt infection

Directory of Open Access Journals (Sweden)

Procop Gary

2008-10-01

Full Text Available Abstract Background Detailed human studies of the mechanisms and development of shunt infection in real time are not possible, and we have developed a canine hydrocephalus model to overcome this. The intention of this pilot study was to show that the canine hydrocephalus model could be shunted using conventional "human" shunts, and that a shunt infection could be established so that further studies could then be planned. Methods Hydrocephalus was induced in seven dogs (Canis familiaris by fourth ventricle obstruction. Four weeks later they were shunted using a Hakim Precision valve. Four of the dogs received shunts whose ventricular catheter had been inoculated with Staphylococcus epidermidis, and three were uninoculated controls. Four weeks after shunting the dogs were sacrificed and necropsy was performed. Removed shunts and tissue samples were examined microbiologically and isolates were subjected to detailed identification and genomic comparison. Results All the dogs remained well after shunting. Examination of removed shunt components revealed S. epidermidis in the brain and throughout the shunt system in the four inoculated animals, but in two of these Staphylococcus intermedius was also found. S. intermedius was also isolated from all three "negative" controls. There were slight differences between S. intermedius strains suggesting endogenous infection rather than cross- infection from a point source. Conclusion Shunt infection was established in the canine model, and had the experiment been extended beyond four weeks the typical microbiological, pathological and clinical features might have appeared. The occurrence of unplanned shunt infections in control animals due to canine normal skin flora reflects human clinical experience and underlines the usual source of bacteria causing shunt infection.

Internal carotid artery rupture caused by carotid shunt insertion.

Science.gov (United States)

Illuminati, Giulio; Caliò, Francesco G; Pizzardi, Giulia; Vietri, Francesco

2015-01-01

Shunting is a well-accepted method of maintaining cerebral perfusion during carotid endarterectomy (CEA). Nonetheless, shunt insertion may lead to complications including arterial dissection, embolization, and thrombosis. We present a complication of shunt insertion consisting of arterial wall rupture, not reported previously. A 78-year-old woman underwent CEA combined with coronary artery bypass grafting (CABG). At the time of shunt insertion an arterial rupture at the distal tip of the shunt was detected and was repaired via a small saphenous vein patch. Eversion CEA and subsequent CABG completed the procedure whose postoperative course was uneventful. Shunting during combined CEA-CABG may be advisable to assure cerebral protection from possible hypoperfusion due to potential hemodynamic instability of patients with severe coronary artery disease. Awareness and prompt management of possible shunt-related complications, including the newly reported one, may contribute to limiting their harmful effect. Arterial wall rupture is a possible, previously not reported, shunt-related complication to be aware of when performing CEA. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ileocolic Arteriovenous Fistula with Superior Mesenteric Vein Aneurism: Endovascular Treatment

International Nuclear Information System (INIS)

Gregorio, Miguel Angel de; Gimeno, Maria Jose; Medrano, Joaquin; Schoenholz, Caudio; Rodriguez, Juan; D'Agostino, Horacio

2004-01-01

We report a case of a venous aneurysm secondary to an acquired ileocolic arteriovenous fistula in a 64-year-old woman with recurrent abdominal pain and history of appendectomy. The aneurysm was diagnosed by ultrasound and computed tomography. Angiography showed an arteriovenous fistula between ileocolic branches of the superior mesenteric artery and vein. This vascular abnormality was successfully treated with coil embolization

Cutaneous blood flow rate in areas with and without arteriovenous anastomoses during exercise

DEFF Research Database (Denmark)

Midttun, M.; Sejrsen, Per

1998-01-01

Arteriovenous anastomoses, capillaries, cutaneous bllod flow rate, exercise, finger blood flow, skin blood flow......Arteriovenous anastomoses, capillaries, cutaneous bllod flow rate, exercise, finger blood flow, skin blood flow...

Prediction of effectiveness of shunting in patients with normal pressure hydrocephalus by cerebral blood flow measurement and computed tomography cisternography

Energy Technology Data Exchange (ETDEWEB)

Chang, Chia-Cheng; Kuwana, Nobumasa; Ito, Susumu; Ikegami, Tadashi [Yokohama Minami Kyosai Hospital (Japan)

1999-11-01

Measurement of cerebral blood flow (CBF) and computed tomography (CT) cisternography were performed in 37 patients with a tentative diagnosis of normal pressure hydrocephalus (NPH) to predict their surgical outcome. The mean CBF of the whole brain was measured quantitatively by single photon emission computed tomography with technetium-99m-hexamethylpropylene amine oxime before surgery. The results of CT cisternography were classified into four patients: type I, no ventricular stasis at 24 hours; type II, no ventricular stasis with delayed clearance of cerebral blush; type III, persistent ventricular stasis with prominent cerebral blush; type IV, persistent ventricular stasis with diminished cerebral blush and/or asymmetrical filling of the sylvian fissures. The mean CBF was significantly lower than that of age-matched controls (p<0.005). Patients with a favorable outcome had a significantly higher mean CBF than patients with an unfavorable outcome (p<0.005). Patients with the type I pattern did not respond to shunting. Some patients with type II and III patterns responded to shunting but improvement was unsatisfactory. Patients with type IV pattern responded well to shunting, and those with a mean CBF of 35 ml/100 g/min or over achieved a favorable outcome. The combination of CBF measurement and CT cisternography can improve the prediction of surgical outcome in patients with suspected NPH. (author)

Prediction of effectiveness of shunting in patients with normal pressure hydrocephalus by cerebral blood flow measurement and computed tomography cisternography

International Nuclear Information System (INIS)

Chang, Chia-Cheng; Kuwana, Nobumasa; Ito, Susumu; Ikegami, Tadashi

1999-01-01

Measurement of cerebral blood flow (CBF) and computed tomography (CT) cisternography were performed in 37 patients with a tentative diagnosis of normal pressure hydrocephalus (NPH) to predict their surgical outcome. The mean CBF of the whole brain was measured quantitatively by single photon emission computed tomography with technetium-99m-hexamethylpropylene amine oxime before surgery. The results of CT cisternography were classified into four patients: type I, no ventricular stasis at 24 hours; type II, no ventricular stasis with delayed clearance of cerebral blush; type III, persistent ventricular stasis with prominent cerebral blush; type IV, persistent ventricular stasis with diminished cerebral blush and/or asymmetrical filling of the sylvian fissures. The mean CBF was significantly lower than that of age-matched controls (p<0.005). Patients with a favorable outcome had a significantly higher mean CBF than patients with an unfavorable outcome (p<0.005). Patients with the type I pattern did not respond to shunting. Some patients with type II and III patterns responded to shunting but improvement was unsatisfactory. Patients with type IV pattern responded well to shunting, and those with a mean CBF of 35 ml/100 g/min or over achieved a favorable outcome. The combination of CBF measurement and CT cisternography can improve the prediction of surgical outcome in patients with suspected NPH. (author)

Transjugular Intrahepatic Portosystemic Shunt Dysfunction: Concordance of Clinical Findings, Doppler Ultrasound Examination, and Shunt Venography

Directory of Open Access Journals (Sweden)

Joshua M Owen

2016-01-01

Full Text Available Objectives: The objective of this study was to evaluate the concordance between clinical symptoms, Doppler ultrasound (US, and shunt venography for the detection of stent-graft transjugular intrahepatic portosystemic shunt (TIPS dysfunction. Materials and Methods: Forty-one patients (M:F 30:11, median age 55 years who underwent contemporaneous clinical exam, Doppler US, and TIPS venography between 2003 and 2014 were retrospectively studied. Clinical symptoms (recurrent ascites or variceal bleeding were dichotomously classified as present/absent, and US and TIPS venograms were categorized in a binary fashion as normal/abnormal. US abnormalities included high/low (>190 or 50 cm/s, absent flow, and return of antegrade intra-hepatic portal flow. Venographic abnormalities included shunt stenosis/occlusion and/or pressure gradient elevation. Clinical and imaging concordance rates were calculated. Results: Fifty-two corresponding US examinations and venograms were assessed. The median time between studies was 3 days. Forty of 52 (77% patients were symptomatic, 33/52 (64% US examinations were abnormal, and 20/52 (38% TIPS venograms were abnormal. Concordance between clinical symptoms and TIPS venography was 48% (25/52, while the agreement between US and shunt venography was 65% (34/52. Clinical symptoms and the US concurred in 60% (31/52 of the patients. The sensitivity of clinical symptoms and US for the detection of venographically abnormal shunts was 80% (16/20 and 85% (17/20, respectively. Both clinical symptoms and the US had low specificity (25%, 8/32 and 50%, 16/32 for venographically abnormal shunts. Conclusion: Clinical findings and the US had low concordance rates with TIPS venography, with acceptable sensitivity but poor specificity. These findings suggest the need for improved noninvasive imaging methods for stent-graft TIPS surveillance.

Impedance Changes Indicate Proximal Ventriculoperitoneal Shunt Obstruction In Vitro.

Science.gov (United States)

Basati, Sukhraaj; Tangen, Kevin; Hsu, Ying; Lin, Hanna; Frim, David; Linninger, Andreas

2015-12-01

Extracranial cerebrospinal fluid (CSF) shunt obstruction is one of the most important problems in hydrocephalus patient management. Despite ongoing research into better shunt design, robust and reliable detection of shunt malfunction remains elusive. The authors present a novel method of correlating degree of tissue ingrowth into ventricular CSF drainage catheters with internal electrical impedance. The impedance based sensor is able to continuously monitor shunt patency using intraluminal electrodes. Prototype obstruction sensors were fabricated for in-vitro analysis of cellular ingrowth into a shunt under static and dynamic flow conditions. Primary astrocyte cell lines and C6 glioma cells were allowed to proliferate up to 7 days within a shunt catheter and the impedance waveform was observed. During cell ingrowth a significant change in the peak-to-peak voltage signal as well as the root-mean-square voltage level was observed, allowing the impedance sensor to potentially anticipate shunt malfunction long before it affects fluid drainage. Finite element modeling was employed to demonstrate that the electrical signal used to monitor tissue ingrowth is contained inside the catheter lumen and does not endanger tissue surrounding the shunt. These results may herald the development of "next generation" shunt technology that allows prediction of malfunction before it affects patient outcome.

Intra-arterial digital subtraction angiography (IA-DSA) with carbon dioxide

International Nuclear Information System (INIS)

Takeda, Toshiaki; Ido, Kunio; Yuasa, Yuji

1988-01-01

Intra-Arterial Digital Subtraction Angiography (IA-DSA) with Carbon Dioxide (CO 2 ) was performed on 41 patients mainly with liver or renal diseases, and its angiographic manifestation was compared with that of conventional angiography. Although the image quality of the arterial or capillary phase was inferior to that of conventional angiography with iodinated contrast media, the detectablity of arterio-venous shunting was excellent. In fact, DSA with CO 2 revealed the presence of A-V (A-P) shunt in 26 patients (26/41:63.4 % HCC, 13/15:86.7% metastatic liver tumor, 2/3:66.7 % RCC, 1/5:20 %). On the other hand, conventional angiography was able to show in only 5 cases. DSA with CO 2 will become an effective method for detecting minute arterio-venous shunting which can not be demonstrated with conventional angiography. (author)

Age related changes in tumor vascularity

International Nuclear Information System (INIS)

Loerelius, L.E.; Stridbeck, H.

1984-01-01

VX 2 tumors in the rabbit hind leg were investigated at one, two and three weeks of age. Angiograms were compared with vascular casts. The tumors grew rapidly the first two weeks of age. Large variations in vascularity were noted between tumors of different ages. With increasing age arteriovenous shunts at the tumor periphery and areas of avascularity of necrosis in the tumor center increased in size. Possible reasons for tumor necrosis are increased tissue pressure, anoxia caused by arteriovenous shunts and elevation in venous pressure. The natural history of the VX 2 tumor must be considered in every experimental study of the effect of any treatment. (orig.)

Relative risk of hemorrhage during pregnancy in patients with brain arteriovenous malformations

NARCIS (Netherlands)

van Beijnum, Janneke; Wilkinson, Tim; Whitaker, Heather J.; van der Bom, Johanna G.; Algra, Ale; Vandertop, W. Peter; van den Berg, René; Brouwer, Patrick A.; Rinkel, Gabriël Je; Kappelle, L. Jaap; Al-Shahi Salman, Rustam; Klijn, Catharina Jm

2017-01-01

Background It is unclear whether the risk of bleeding from brain arteriovenous malformations is higher during pregnancy, delivery, or puerperium. We compared occurrence of brain arteriovenous malformation hemorrhage in women during this period with occurrence of hemorrhage outside this period during

Transitional Flow in an Arteriovenous Fistula: Effect of Wall Distensibility

Science.gov (United States)

McGah, Patrick; Leotta, Daniel; Beach, Kirk; Aliseda, Alberto

2012-11-01

Arteriovenous fistulae are created surgically to provide adequate access for dialysis in patients with end-stage renal disease. Transitional flow and the subsequent pressure and shear stress fluctuations are thought to be causative in the fistula failure. Since 50% of fistulae require surgical intervention before year one, understanding the altered hemodynamic stresses is an important step toward improving clinical outcomes. We perform numerical simulations of a patient-specific model of a functioning fistula reconstructed from 3D ultrasound scans. Rigid wall simulations and fluid-structure interaction simulations using an in-house finite element solver for the wall deformations were performed and compared. In both the rigid and distensible wall cases, transitional flow is computed in fistula as evidenced by aperiodic high frequency velocity and pressure fluctuations. The spectrum of the fluctuations is much more narrow-banded in the distensible case, however, suggesting a partial stabilizing effect by the vessel elasticity. As a result, the distensible wall simulations predict shear stresses that are systematically 10-30% lower than the rigid cases. We propose a possible mechanism for stabilization involving the phase lag in the fluid work needed to deform the vessel wall. Support from an NIDDK R21 - DK08-1823.

Research on spark discharge of floating roof tank shunt

International Nuclear Information System (INIS)

Bi, Xiaolei; Liu, Quanzhen; Liu, Baoquan; Gao, Xin; Hu, Haiyan; Liu, Juan

2013-01-01

In order to quantitatively analyze the spark discharge risk of floating roof tank shunts, the breakdown voltage of shunt has been calculated by Townsend theory, the shunt spark discharge experiment is carried out by using 1.2/50 μs impulse voltage wave, and the relationship between breakdown voltage of shunt spark discharge and air gap is analyzed. It has been indicated by theoretical analysis and experimental study that the small gap is more easily cause spark discharge than the big gap when the contact between shunt and tank shell is poor. When air gap distance is equal to 0.1 cm, average breakdown voltage is 5280 V. When the air gap distance is less than 0.3 cm, experiment data agree well with Townsend theory. Therefore, in the condition of small gap, Townsend theory can be used to calculated breakdown voltage of shunt. Finally, based on the above conclusions, improvements for avoiding the spark discharge risk of shunt of floating roof tanks have been proposed.

Novel surgical procedures in glaucoma: advances in penetrating glaucoma surgery.

Science.gov (United States)

Filippopoulos, Theodoros; Rhee, Douglas J

2008-03-01

Despite late modifications and enhancements, traditional penetrating glaucoma surgery is not without complications and is reserved for patients in whom pharmacologic treatment and/or laser trabeculoplasty do not suffice to control the intraocular pressure. This article critically reviews recent advances in penetrating glaucoma surgery with particular attention paid to two novel surgical approaches: ab interno trabeculectomy with the Trabectome and implantation of the Ex-PRESS shunt. Ab interno trabeculectomy (Trabectome) achieves a sustained 30% reduction in intraocular pressure by focally ablating and cauterizing the trabecular meshwork/inner wall of Schlemm's canal. It has a remarkable safety profile with respect to early hypotonous or infectious complications as it does not generate a bleb, but it can be associated with early postoperative intraocular pressure spikes that may necessitate additional glaucoma surgery. The Ex-PRESS shunt is more commonly implanted under a partial thickness scleral flap, and appears to have similar efficacy to standard trabeculectomy offering some advantages with respect to the rate of early complications related to hypotony. Penetrating glaucoma surgery will continue to evolve. As prospective randomized clinical trials become available, we will determine the exact role of these surgical techniques in the glaucoma surgical armamentarium.

Percutaneous transfermoral embolization of intracerebral arteriovenous malformation by using conventional catheter

International Nuclear Information System (INIS)

Choo, In Wook; Park, Soo Sung; Yoon, Jung Sup; Lim, Hyo Keun; Lee, Kyu Ho; Eoh, Whan

1988-01-01

Non-surgical transfermoral embolization of centrally located huge intracerebral arteriovenous malformation (AVM) was successfully performed by using conventional 6.5F DAVIS II Catheter in the department of Radiology, Kangdong Sacred Heart Hospital, May 17, 1988. The large A.V.M. was located in left basal ganglia and thalamus on brain C.T. and was supplied by multiple dilated lateral lenticulostriate arteries from left middle cerebral artery and posterior thalamoperforating artery, posterior choroidal artery from left posterior cerebral artery angiographically. The AVM was partially obliterated after embolization of lateral lenticulostriate arteries and thalamoperforating artery with P.V.A. (Polyvinyl Alcohol, ivalon) using conventional 6.5F DAVIS II angiographic catheter. There was no complication which was related to those embolization procedures except transient drowsy consciousness after embolization but it is completely recovered to the level of preembolization state after 10 hours.

Ectopic cystoperitoneal shunt demonstrated by valvulography. A case report

Energy Technology Data Exchange (ETDEWEB)

Jofre, M J; Sierralta, M P [Military Hospital Nuclear Medicine Department, Santiago (Chile)

2002-09-01

The most important and frequent complications in the management of hydrocephalus treated with a derivation system are the infection and obstruction of the ventriculoperitoneal or ventriculoatrial shunt. However, another less frequent problem is the migration of the distal catheter. The case report presented is a 20 year-old girl who started, when she was 12, with severe headaches and epileptogenic seizures. She was diagnosed with a left parietotemporal aracnoidal cyst and a cystoperitoneal shunt was installed. However, she continued to have headaches. In September 1999, the derivation system was controlled with a radionuclide valvulography, which demonstrated shunt patency, with mild ectasis in the distal region. In July 2000, another valvulography showed a malfunction of the cystoperitoneal system. The distal catheter was surgically reviewed and repositioned. A few months of being asymptomatic, the headaches returned with a cough, which didn't respond to treatment. In February of 2002, she was referred to the Military Hospital Nuclear Medicine Department and a radionuclide valvulography was performed with 370 MBq of Tc99m-DTPA, injected in the derivative system reservoir. Images showed a slow descension of the radionuclide until the xifoides region where the distal catheter had formed a loop into the chest. Free activity was observed at the end of the catheter with another abnormal traject in the middle chest up to the top of the sternum. A pumping test was done and the patient coughed and said that she 'felt water' in her mouth. A simple abdomen X-ray was performed confirming the distal catheter in the upper side of the diaphragm. A third surgery was performed demonstrating that the catheter had an intraperitoneal loop with the distal end in the chest. They pulled the catheter and the distal end was repositioned into the peritoneal cavity, controlling its functioning. A simple abdomen X-ray verified the position. In the following days the patient had no headache

Ectopic cystoperitoneal shunt demonstrated by valvulography. A case report

International Nuclear Information System (INIS)

Jofre, M.J.; Sierralta, M.P.

2002-01-01

The most important and frequent complications in the management of hydrocephalus treated with a derivation system are the infection and obstruction of the ventriculoperitoneal or ventriculoatrial shunt. However, another less frequent problem is the migration of the distal catheter. The case report presented is a 20 year-old girl who started, when she was 12, with severe headaches and epileptogenic seizures. She was diagnosed with a left parietotemporal aracnoidal cyst and a cystoperitoneal shunt was installed. However, she continued to have headaches. In September 1999, the derivation system was controlled with a radionuclide valvulography, which demonstrated shunt patency, with mild ectasis in the distal region. In July 2000, another valvulography showed a malfunction of the cystoperitoneal system. The distal catheter was surgically reviewed and repositioned. A few months of being asymptomatic, the headaches returned with a cough, which didn't respond to treatment. In February of 2002, she was referred to the Military Hospital Nuclear Medicine Department and a radionuclide valvulography was performed with 370 MBq of Tc99m-DTPA, injected in the derivative system reservoir. Images showed a slow descension of the radionuclide until the xifoides region where the distal catheter had formed a loop into the chest. Free activity was observed at the end of the catheter with another abnormal traject in the middle chest up to the top of the sternum. A pumping test was done and the patient coughed and said that she 'felt water' in her mouth. A simple abdomen X-ray was performed confirming the distal catheter in the upper side of the diaphragm. A third surgery was performed demonstrating that the catheter had an intraperitoneal loop with the distal end in the chest. They pulled the catheter and the distal end was repositioned into the peritoneal cavity, controlling its functioning. A simple abdomen X-ray verified the position. In the following days the patient had no headache

Delayed radiation necrosis 7 years after gamma knife surgery for arteriovenous malformation. Two case reports

International Nuclear Information System (INIS)

Oyoshi, Tatsuki; Yatsushiro, Kazutaka; Arita, Kazunori; Hirahara, Kazuho; Uetsuhara, Koichi

2010-01-01

A 44-year-old woman and a 55-year-old woman were treated with gamma knife surgery (GKS) for occipital arteriovenous malformation (AVM). Angiography confirmed complete nidus obliterations 2 years after GKS. However, both patients complained of chronic headache and visual symptoms from around 7 years after GKS. Magnetic resonance imaging showed round masses with or without cystic change surrounded by large areas of brain edema. Angiography also showed complete obliteration of AVM at this time. Extended corticosteroid treatment failed to control the edema. Both patients underwent total surgical removal of the mass. Visual disturbance and chronic headache improved postoperatively and the brain edema rapidly subsided. The histological diagnosis was radiation necrosis in both cases, attributed to the low conformity index and large 12-Gy volume due to usage of a large collimator for GKS. These cases of delayed radiation necrosis after GKS suggest that surgical removal of necrotic lesions is necessary for radiation necrosis intractable to medical treatment. (author)

Use of mathematic modeling to compare and predict hemodynamic effects of the modified Blalock-Taussig and right ventricle-pulmonary artery shunts for hypoplastic left heart syndrome.

Science.gov (United States)

Bove, Edward L; Migliavacca, Francesco; de Leval, Marc R; Balossino, Rossella; Pennati, Giancarlo; Lloyd, Thomas R; Khambadkone, Sachin; Hsia, Tain-Yen; Dubini, Gabriele

2008-08-01

Stage one reconstruction (Norwood operation) for hypoplastic left heart syndrome can be performed with either a modified Blalock-Taussig shunt or a right ventricle-pulmonary artery shunt. Both methods have certain inherent characteristics. It is postulated that mathematic modeling could help elucidate these differences. Three-dimensional computer models of the Blalock-Taussig shunt and right ventricle-pulmonary artery shunt modifications of the Norwood operation were developed by using the finite volume method. Conduits of 3, 3.5, and 4 mm were used in the Blalock-Taussig shunt model, whereas conduits of 4, 5, and 6 mm were used in the right ventricle-pulmonary artery shunt model. The hydraulic nets (lumped resistances, compliances, inertances, and elastances) were identical in the 2 models. A multiscale approach was adopted to couple the 3-dimensional models with the circulation net. Computer simulations were compared with postoperative catheterization data. Good correlation was found between predicted and observed data. For the right ventricle-pulmonary artery shunt modification, there was higher aortic diastolic pressure, decreased pulmonary artery pressure, lower Qp/Qs ratio, and higher coronary perfusion pressure. Mathematic modeling predicted minimal regurgitant flow in the right ventricle-pulmonary artery shunt model, which correlated with postoperative Doppler measurements. The right ventricle-pulmonary artery shunt demonstrated lower stroke work and a higher mechanical efficiency (stroke work/total mechanical energy). The close correlation between predicted and observed data supports the use of mathematic modeling in the design and assessment of surgical procedures. The potentially damaging effects of a systemic ventriculotomy in the right ventricle-pulmonary artery shunt modification of the Norwood operation have not been analyzed.

Prevalence of brain arteriovenous malformations in first-degree relatives of patients with a brain arteriovenous malformation

NARCIS (Netherlands)

van Beijnum, Janneke; van der Worp, H. Bart; Algra, Ale; Vandertop, W. Peter; van den Berg, René; Brouwer, Patrick A.; van der Sprenkel, Jan Willem Berkelbach; Kappelle, L. Jaap; Rinkel, Gabriël J. E.; Klijn, Catharina J. M.

2014-01-01

It is uncertain whether familial occurrence of brain arteriovenous malformations (BAVMs) represents coincidental aggregation or a shared familial risk factor. We aimed to compare the prevalence of BAVMs in first-degree relatives (FDRs) of patients with BAVM and the prevalence in the general

Cerebrovascular Accident Secondary to Paradoxical Embolism Following Arteriovenous Graft Thrombectomy

OpenAIRE

Santos, Jolina Pamela; Hamadeh, Zaher; Ansari, Naheed

2012-01-01

Thrombectomy is a common procedure performed to declot thrombosed dialysis arteriovenous fistula (AVF) or arteriovenous graft (AVG). Complications associated with access thrombectomy like pulmonary embolism have been reported, but paradoxical embolism is extremely rare. We report a case of a 74-year-old black man with past medical history significant for end-stage renal disease (ESRD), atrial fibrillation on anticoagulation with warfarin, who presented to our hospital with lethargy, aphasia, ...

Spontane abdominale arteriovenøse fistler

DEFF Research Database (Denmark)

Flarup, S; Lindholt, Jes Sanddal

1997-01-01

Spontaneous arteriovenous fistulas between major abdominal vessels (AAVF) complicates about 1% of abdominal aortic aneurysms. AAVF produces severe circulatory disturbances with high operative mortality. Preoperative diagnosis is important but difficult due to the varied nature of presentation. Fo...

Gamma knife radiosurgery for arteriovenous malformation in children

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Takayuki; Kobayashi, Tatsuya [Komaki City Hospital, Aichi (Japan)

1995-04-01

Intracranial arteriovenous malformations (AVM) of 38 children were treated by gamma knife radiosurgery. Their clinical courses and the effect of the treatment in 19 patients who had angiographies are described. There were 21 boys and 17 girls with a mean age of 11.2 years. The initial signs and symptoms were: intracranial hemorrhage in 32, seizures in 4, and headache in 2. Prior to the radiosurgery, craniotomy was performed in 10 patients, ventricular drainage, in 8, ventriculoperitoneal shunting in 4, and intravascular embolization in 3. The AVM was in the parietal lobe in 8 patients, in the thalamus in 7, in the occipital lobe in 5, in the temporal lobe in 4, in the basal ganglia in 4, in the corpus callosum in 3, and in other locations in 8. The mean diameter of the nidus was 18.9 mm. According to Spetzler`s classification of AVM, 23 (60.5%) were grade III, 10 were grade II, 3 were grade IV, and 2 were grade VI. The mean maximum dose was 36.3 Gy, and the mean peripheral dose was 20.2 Gy. Follow-up angiography was done in 19 patients during a mean follow-up period of 14.9 months. Complete occlusion of the nidus was obtained within 1 year in 10 of 15 patients (67%). All 6 patients who underwent angiography 2 years after treatment showed complete obliteration of the AVM. Only 1 patient developed hemiparesis due to radiation necrosis. It is considered that occlusion of AVMs by gamma knife radiosurgery is probably more effective and safer in children than in adults. (author).

Surgical options for treatment of traumatic subdural hematomas in children younger than 2 years of age.

Science.gov (United States)

Melo, José Roberto Tude; Di Rocco, Federico; Bourgeois, Marie; Puget, Stephanie; Blauwblomme, Thomas; Sainte-Rose, Christian; Meyer, Philippe G; Zerah, Michel

2014-04-01

Subdural hematoma (SDH) is the most common finding on cranial CT in pediatric victims of abusive head trauma (AHT). The hematomas are commonly bilateral and sometimes associated with interhemispheric hyperdensity and/or convexity hemorrhages. There is no consensus regarding the best surgical treatment in such cases nor are there standardized surgical protocols. The authors report their experience and discuss the routine surgical options in the management of traumatic SDH at a Level 1 Pediatric Trauma Center. In this paper, the authors describe a cross-sectional study with consecutive revision of data described in the medical records of Hôpital Universitaire Necker-Enfants Malades between January 2008 and January 2013. During this period, all children younger than 2 years of age who were admitted with a traumatic SDH identified on CT scans were included in this study. One hundred eighty-four children who had SDH and were younger than 2 years of age were included. Their median age was 5.8 months (range 5 days-23 months), and 70% of the children were male. On admission CT scans, the SDH was bilateral in 52% of cases and homogeneously hypodense in 77%. Neurosurgical treatment was undertaken in 111 children (60%) with an admission Glasgow Coma Scale score of 12 or less, bulging fontanels, or other signs suggestive of intracranial hypertension. The first surgical option was craniotomy in 1.8% (2) of these 111 cases, decompressive craniectomy in 1.8% (2), transcutaneous subdural puncture in 15% (17), external subdural drainage in 16% (18), subdural-subgaleal shunt placement in 17% (19), and subdural-peritoneal shunt placement in 48% (53). In 82% of the children initially treated with transcutaneous subdural puncture and in 50% of those treated with external subdural drainage, increase or persistence of the SDH, CSF or skin infection, or shunt system malfunction was observed and further surgical intervention was required. There was a 26% rate of complications in patients

Evaluation of Blalock-Taussig shunts using magnetic resonance imaging

International Nuclear Information System (INIS)

Okajima, Yoshitomo; Tashima, Kazuyuki; Terai, Masaru; Niwa, Koichirou.

1988-01-01

Four patients aged 3 to 18 months (mean 13 months) with a total of five Blalock-Taussig shunts (BT shunts; two were original BT shunts and three were modified BT shunts using GOLASKI grafts) underwent evaluation by ECG-gated magnetic resonance imaging. There were two cases with pulmonary atresia with intact ventricular septum, one with double outlet right ventricle with pulmonary stenosis and one with tetralogy of Fallot with pulmonary atresia who underwent bilateral BT shunts. At the time of study, an auscultory shunt murmur was audible in all patients. The magnetic resonance images were obtained with a Picker International Vista MR with a superconducting magnet operating at 0.5 Tesla. A spin echo sequence (echo time 40 msec) was used. All patients were placed within a 30 cm head coil radio antenna and sedated with chloral hydrate or diazepam. Four of 5 shunts were imaged on both coronal sections and sagittal sections during enddiastole. And there was no signal within the grafts. When the velocity of blood flow is beyond the cutoff velocity, the signal intensity of flowing blood is near background level. So we judged these grafts were patient. Our results showed that MRI was a very useful noninvasive method for evaluation of BT shunts. (author)

Evaluation of Blalock-Taussig shunts using magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Okajima, Yoshitomo; Tashima, Kazuyuki; Terai, Masaru; Niwa, Koichirou.

1988-10-01

Four patients aged 3 to 18 months (mean 13 months) with a total of five Blalock-Taussig shunts (BT shunts; two were original BT shunts and three were modified BT shunts using GOLASKI grafts) underwent evaluation by ECG-gated magnetic resonance imaging. There were two cases with pulmonary atresia with intact ventricular septum, one with double outlet right ventricle with pulmonary stenosis and one with tetralogy of Fallot with pulmonary atresia who underwent bilateral BT shunts. At the time of study, an auscultory shunt murmur was audible in all patients. The magnetic resonance images were obtained with a Picker International Vista MR with a superconducting magnet operating at 0.5 Tesla. A spin echo sequence (echo time 40 msec) was used. All patients were placed within a 30 cm head coil radio antenna and sedated with chloral hydrate or diazepam. Four of 5 shunts were imaged on both coronal sections and sagittal sections during enddiastole. And there was no signal within the grafts. When the velocity of blood flow is beyond the cutoff velocity, the signal intensity of flowing blood is near background level. So we judged these grafts were patient. Our results showed that MRI was a very useful noninvasive method for evaluation of BT shunts.

Ventriculoperitoneal shunt infection in Haji Adam Malik Hospital, Medan

Science.gov (United States)

Dharmajaya, R.

2018-03-01

Installation of ventriculoperitoneal shunts (VP) represented a substantial progress in the neurosurgical management of hydrocephalus in children. However, infection is the most commonpostoperative complication of aventriculoperitoneal shunt. It is important because it is related to substantial morbidity and mortality, and exerts a negative impact on the quality of life of patients. We retrospectively analyzed all 20 cases of shunt infection from 2013 to 2016. The types of infections found were exposed shunts15 cases (75%), and 5 cases of ventriculitis (25%). Length of infection time which calculated from the beginning of surgery was 350.20 days or 11 months. The most common pathogen types are S. epidermidis followed by P. aeruginosa, E. coli, and A. baumanii. There were many risk factors for shunt infection, but the interesting fact was the level of pre-operative albumin. There was a significant difference between low albumin levels (<3.0) and normal albumin (≥3.0) levels against the risk of exposure shunt, p = 0.015. It means there is asignificant difference between low pre-operative albumin and normal level for the risk of theexposed shunt.

Combined Glaucoma Tube Shunt (Ahmed) and Fluocinolone Acetonide (Retisert™) Implantation Compared to Ahmed Alone in Uveitic Glaucoma.

Science.gov (United States)

Zivney, Mark; Lin, Phoebe; Edmunds, Beth; Parikh, Mansi; Takusagawa, Hana; Tehrani, Shandiz

2016-12-01

Glaucoma is a known complication of uveitis, and may require glaucoma tube shunt implantation for intraocular pressure (IOP) control. The success of glaucoma tube shunt implantation in the setting of a local ocular steroid depot in uveitic glaucoma remains unknown. The purpose of this study was to determine whether patients who underwent combined glaucoma tube shunt (Ahmed) and fluocinolone acetonide (Retisert™, Bausch + Lomb, Bridgewater, NJ, USA) implantation have superior outcomes compared to patients with Ahmed implants only in the setting of uveitic glaucoma. All participants were studied retrospectively and underwent Ahmed implantation alone or with existing/concurrent Retisert implantation (combined group) at a single academic institution. The main outcome measures were IOP, visual acuity (VA), number of IOP-lowering medications, and adverse events at 6 months after Ahmed implantation. Secondary outcome measures included adverse events and surgical success at 6 months after Ahmed implantation. Mean IOP at 6 months after Ahmed implantation was 15.3 ± 4.8 and 15.1 ± 4.9 mm Hg in the Ahmed only group (n = 17) and the combined group (n = 17), respectively (p = 0.89). The mean number of IOP-lowering medications at 6 months after Ahmed implantation was 1.7 ± 1.0 and 1.8 ± 1.0 in the Ahmed only group and the combined group, respectively (p = 0.86). Mean VA at 6 months after Ahmed implantation was 0.35 ± 0.29 and 0.42 ± 0.33 log mean angle of resolution in the Ahmed only group and the combined group, respectively (p = 0.50). No significant differences in surgical success or adverse events were noted between the two groups. At 6 months, no significant differences in mean IOP, mean number of IOP-lowering medications, VA, surgical success, or adverse events were noted between Ahmed implantation alone or combined Ahmed and Retisert implantation in patients with uveitic glaucoma.

Indicators of surgical treatment of patent ductus arteriosus in preterm neonates in the first week of life

Directory of Open Access Journals (Sweden)

Renato Braulio

2013-12-01

Full Text Available OBJECTIVE: To identify clinical and echocardiographic indicators of the necessity for early surgical closure of patent ductus arteriosus in preterm neonates. METHODS: The prospective study was conducted at the Neonatal Unit of Hospital Municipal Odilon Behrens between 2006 and 2010. The study population comprised 115 preterm neonates diagnosed with patent ductus arteriosus in the first week after birth, of whom 55 (group S were submitted to clinical and or surgical closure and 60 (group NS received non-surgical treatment. The parameters analyzed were birth weight, diameter of the ductus arteriosus (DAD, left atrial-to-aortic root diameter ratio (LA:Ao, the quotient of DAD² and birth weight (mm²/kg, and ductal shunting. RESULTS: The study population comprised 58 males and 57 females. The average birth weight of group S (924 ± 224.3 g was significantly (P=0.049 lower than that of group NS (1012.3 ± 242.8 g. The probability of the preterm neonates being submitted to surgical closure was 62.1% (P=0.006 when the DAD2/birth weight index was > 5 mm²/kg, 72.2% (P=0.001 when the LA:Ao ratio was > 1.5, and 61.2% when ductal shunting was high (P=0.025. CONCLUSION: The parameters DAD²/birth weight index > 5 mm²/kg, LA:Ao ratio > 1.5 and high ductal shunting were statistically significant indicators (P 1.5 was associated with the occurrence of shock, the probability of surgical closure increased to 78.4%.

Pulmonary Arteriovenous Malformations Embolized Using a Micro Vascular Plug System: Technical Note on a Preliminary Experience

Energy Technology Data Exchange (ETDEWEB)

Boatta, Emanuele, E-mail: emanuele.boatta@yahoo.it; Jahn, Christine, E-mail: christine.jahn@chru-strasbourg.fr [Hôpitaux Universitaires de Strasbourg, Service de Imagerie Interventionelle, Nouvel Hôpital Civil (France); Canuet, Matthieu, E-mail: matthieu.canuet@chru-strasbourg.fr [Hôpitaux Universitaires de Strasbourg, Service Service de Pneumologie, Nouvel Hôpital Civil (France); Garnon, Julien, E-mail: juleiengarnon@gmail.com [Hôpitaux Universitaires de Strasbourg, Service de Imagerie Interventionelle, Nouvel Hôpital Civil (France); Ramamurthy, Nitin, E-mail: nitin-ramamurthy@hotmail.com [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Gangi, Afshin, E-mail: gangi@unistra.fr [Hôpitaux Universitaires de Strasbourg, Service de Imagerie Interventionelle, Nouvel Hôpital Civil (France)

2017-02-15

AIMTo report our preliminary experience using a Micro Vascular Plug (MVP) deployed through a 2.8Fr micro-catheter for the treatment of pulmonary arteriovenous malformations (PAVMs) in a cohort of patients affected by Hereditary Haemorrhagic Telangiectasia (HHT).Materials and MethodsFour consecutive female patients (mean age 38.0 years; range 25–55 years) with PAVMs diagnosed on echocardiogram/bubble test and contrast-enhanced CT (CECT) underwent MVP embolization. One patient was symptomatic with recent transient ischaemic attack. Follow-up was undertaken at 1-month post-procedure with CECT to assess PAVMs permeability and MVP positioning and at 1-, 6-, and 12-month post-procedure, with echocardiography/bubble test and standard neurological history, to confirm absence of right-to-left shunts and recurrent symptoms.ResultsEight PAVMs were treated in 4 patients over 5 interventional sessions (mean 1.6 PAVMs per session). All PAVMs were simple, with mean feeding artery diameter of 4.25 mm. Eight 6.5 mm MVPs were deployed in total (one per lesion). Technical success was 100%. Mean procedural time and patient dose per session were 70 min (range 40–70 min) and 53418 mGy.cm{sup 2} (range 6113–101628 mGy.cm{sup 2}), respectively. No signs of reperfusion neither of MPV migration were noted at 1-month CECT follow-up. At early follow-up (mean 3.75 months; range 1–12 months), clinical success was 100% with no evidence of recurrent right-to-left shunt, and no neurological symptoms. No immediate or late complications were observed.ConclusionsMVP embolization of PAVMs appears technically feasible, safe, and effective at early follow-up. Further prospective studies are required to confirm long-term safety and efficacy of this promising technique.

The somatic shunt cable model for neurons.

OpenAIRE

Durand, D

1984-01-01

The derivation of the equations for an electrical model of nerve cells is presented. The model consists of an equivalent cylinder, a lumped somatic impedance, and a variable shunt at the soma. This shunt was introduced to take into account the fast voltage decays observed following the injections of current pulses in some motoneurons and hippocampal granule cells that could not be explained by existing models. The shunt can be interpreted either by penetration damage with the electrode or by ...

Simulation model for port shunting yards

Science.gov (United States)

Rusca, A.; Popa, M.; Rosca, E.; Rosca, M.; Dragu, V.; Rusca, F.

2016-08-01

Sea ports are important nodes in the supply chain, joining two high capacity transport modes: rail and maritime transport. The huge cargo flows transiting port requires high capacity construction and installation such as berths, large capacity cranes, respectively shunting yards. However, the port shunting yards specificity raises several problems such as: limited access since these are terminus stations for rail network, the in-output of large transit flows of cargo relatively to the scarcity of the departure/arrival of a ship, as well as limited land availability for implementing solutions to serve these flows. It is necessary to identify technological solutions that lead to an answer to these problems. The paper proposed a simulation model developed with ARENA computer simulation software suitable for shunting yards which serve sea ports with access to the rail network. Are investigates the principal aspects of shunting yards and adequate measures to increase their transit capacity. The operation capacity for shunting yards sub-system is assessed taking in consideration the required operating standards and the measure of performance (e.g. waiting time for freight wagons, number of railway line in station, storage area, etc.) of the railway station are computed. The conclusion and results, drawn from simulation, help transports and logistics specialists to test the proposals for improving the port management.

Shunt protection for superconducting Maglev magnets

Energy Technology Data Exchange (ETDEWEB)

Atherton, D L [Queen' s Univ., Kingston, Ontario (Canada). Dept. of Physics

1979-09-01

Closely coupled, short-circuited shunt coils are proposed for quench protection of superconducting Maglev magnets which use high resistance, matrix composite conductors. It is shown that, by suitable design, the shunts can reduce induced ac losses and that the changing currents during magnet energization or vehicle lift off and landing can be tolerated.

Effect of electromagnetic navigated ventriculoperitoneal shunt placement on failure rates.

Science.gov (United States)

Jung, Nayoung; Kim, Dongwon

2013-03-01

To evaluate the effect of electromagnetic (EM) navigation system on ventriculoperitoneal (VP) shunt failure rate through comparing the result of standard shunt placement. All patients undergoing VP shunt from October 2007 to September 2010 were included in this retrospective study. The first group received shunt surgery using EM navigation. The second group had catheters inserted using manual method with anatomical landmark. The relationship between proximal catheter position and shunt revision rate was evaluated using postoperative computed tomography by a 3-point scale. 1) Grade I; optimal position free-floating in cerebrospinal fluid, 2) Grade II; touching choroid or ventricular wall, 3) Grade III; tip within parenchyma. A total of 72 patients were participated, 27 with EM navigated shunts and 45 with standard shunts. Grade I was found in 25 patients from group 1 and 32 patients from group 2. Only 2 patients without use of navigation belonged to grade III. Proximal obstruction took place 7% in grade I, 15% in grade II and 100% in grade III. Shunt revision occurred in 11% of group 1 and 31% of group 2. Compared in terms of proximal catheter position, there was growing trend of revision rate according to increase of grade on each group. Although infection rate was similar between both groups, the result had no statistical meaning (p=0.905, chi-square test). The use of EM navigation in routine shunt surgery can eliminate poor shunt placement resulting in a dramatic reduction in failure rates.

Shunt protection for superconducting Maglev magnets

International Nuclear Information System (INIS)

Atherton, D.L.

1979-01-01

Closely coupled, short-circuited shunt coils are proposed for quench protection of superconducting Maglev magnets which use high resistance, matrix composite conductors. It is shown that, by suitable design, the shunts can reduce induced ac losses and that the changing currents during magnet energization or vehicle lift off and landing can be tolerated. (author)

The Rendu-Osler-Weber Disease Revealed by a Refractory Hypoxemia and Severe Cerebral Fat Embolism

Directory of Open Access Journals (Sweden)

Leonel Barreto

2013-01-01

Full Text Available The Rendu-Osler-Weber disease is a genetic disease which may lead to severe hemorrhage and less frequently to severe organ dysfunction. We report the case of a 22-year-old patient with no personal medical history who was involved in a motorcycle accident and exhibited severe complications related to large arteriovenous pulmonary shunts during his ICU stay. The patient developed an unexplained severe hypoxemia which was attributed to several arteriovenous shunts of the pulmonary vasculature by a contrast study during a transesophageal echocardiographic examination. The course was subsequently complicated by a prolonged coma associated with hemiplegia which was attributed to a massive paradoxical fat embolism in the setting of an untreated femoral fracture. In addition to hemorrhagic complications which may lead to intractable shock, arteriovenous malformations associated with the Rendu-Osler-Weber disease may involve the pulmonary vasculature and result in unexpected complications, such as hypoxemia or severe cerebral fat embolism in high-risk patients.

Use of i.v. radionuclide total body arteriography to evaluate arterial bypass shunts--a new method--a review of several cases

International Nuclear Information System (INIS)

Yang, D.C.; Jain, C.U.; Patel, D.; Gould, L.; Schaefer, H.; Maghazeh, P.; Giovanniello, J.

1990-01-01

Currently, Doppler ultrasound and contrast angiography are the main imaging procedures being used to evaluate arterial bypass shunts. IV radionuclide total body arteriography (TBA) is another useful imaging procedure for evaluation of bypass shunts. The authors reviewed 33 patients, 19 women and 14 men, ranging in age from forty-three to eighty-five, who had TBA done after arterial bypass surgery. Ten patients had multiple shunts and 5 had multiple follow-up studies. In total there were 80 shunts, including 43 femoropopliteal, 16 axillofemoral, 1 axillopopliteal, 13 crossover femorofemoral, and 7 aortofemoral shunts. Sixty-two of the 80 shunts were patent, 14 were occluded, and 4 had partial occlusion. The results were confirmed by Doppler studies, contrast angiograms, and/or surgical exploration without false positives or false negatives. Since the radiotracer used was 99mTc-labeled red blood cells, a MUGA study can also be performed immediately following TBA in the same injection. Twenty-eight patients had gated cardiac blood pool studies (MUGA) done; 16 had abnormal wall motion and diminished ventricular function. TBA requires only a single IV injection of radiotracer (less than 1 cc) in the upper limb. The imaging times for total body arterial and perfusion images are seventy seconds and five minutes respectively. Both total body arterial and perfusion images clearly demonstrated the entire course of shunts (single or multiple); underlying and coexisting arterial abnormalities, e g, occlusive disease (27 patients), or aneurysm (3 patients); and related perfusion changes in the extremities. TBA has unique features. It permits a complete, excellent visualization of the bypass graft without the hazard of contrast media injection. It is a simple and a virtually noninvasive procedure, particularly useful for preoperative workups and postoperative follow-ups

Percutaneous peritoneovenous shunt positioning: technique and preliminary results

International Nuclear Information System (INIS)

Orsi, Franco; Grasso, Rosario Francesco; Bonomo, Guido; Marinucci, Irene; Monti, Cinzia; Bellomi, Massimo

2002-01-01

Nine peritoneovenous shunts were positioned by percutaneous technique in seven patients with advanced malignancy causing severe refractory ascites, and in two patients with hepatic cirrhosis (one with hepatocarcinoma). In all patients the shunts were percutaneously placed through the subclavian vein in the angiographic suite under digital fluoroscopic guide. No complications directly related to the procedure occurred. The shunt was successfully positioned in all patients in 60 min average time. No patient showed symptoms related to pulmonary overload or to disseminated intravascular coagulation. All patients had a significant improvement of the objective symptoms related to ascites such as respiratory symptoms, dyspepsia, and functional impairment to evacuation describing an improvement of their quality of life. Maximum shunt patency was 273 days. Percutaneous placement of peritoneovenous shunt is a safe, fast, and inexpensive procedure, extremely useful in resolution of refractory ascites, reducing symptoms, and allowing effective palliation, with a great improvement in quality of life. (orig.)

Percutaneous peritoneovenous shunt positioning: technique and preliminary results

Energy Technology Data Exchange (ETDEWEB)

Orsi, Franco; Grasso, Rosario Francesco; Bonomo, Guido; Marinucci, Irene [Division of Radiology, European Institute of Oncology, Milan (Italy); Monti, Cinzia [Institute of Radiology, University of Milan (Italy); Bellomi, Massimo [Division of Radiology, European Institute of Oncology, Milan (Italy); Institute of Radiology, University of Milan (Italy)

2002-05-01

Nine peritoneovenous shunts were positioned by percutaneous technique in seven patients with advanced malignancy causing severe refractory ascites, and in two patients with hepatic cirrhosis (one with hepatocarcinoma). In all patients the shunts were percutaneously placed through the subclavian vein in the angiographic suite under digital fluoroscopic guide. No complications directly related to the procedure occurred. The shunt was successfully positioned in all patients in 60 min average time. No patient showed symptoms related to pulmonary overload or to disseminated intravascular coagulation. All patients had a significant improvement of the objective symptoms related to ascites such as respiratory symptoms, dyspepsia, and functional impairment to evacuation describing an improvement of their quality of life. Maximum shunt patency was 273 days. Percutaneous placement of peritoneovenous shunt is a safe, fast, and inexpensive procedure, extremely useful in resolution of refractory ascites, reducing symptoms, and allowing effective palliation, with a great improvement in quality of life. (orig.)

Percutaneous closure of postoperative ventricular septal residual left-to-right shunt with the China made device

International Nuclear Information System (INIS)

Qin Yongwen; Zhao Xianxian; Wu Hong; Ding Jijun; Cao Jiang; Zheng Xin

2007-01-01

Objective: To evaluate the feasibility and efficacy of percutaneous transcatheter closure of residual ventricular septal defect (VSD)after surgical closure using China made-nitinol VSD device. Methods: Transcatheter closure was attempted in 11 patients (5 males, 6 females)with a residual VSD following surgical closure. The mean residual VSD narrowest diameter was(5.82 ± 2.09) mm (range from 3 to 9 mm)by echocardiography. A 6 F-9 F delivery sheath was advanced across the residual VSD over a guidewire from femoral vein to deploy the occluder under guidance of left ventriculography and transthoracic echocardiography. Results: The left ventriculography showed membranous part aneurism-like residual VSD in 8 patients and funnel type in 3 cases. There were multiple outlet in 5 cases and one outlets in 6 cases, with mean residual VSD narrowest diameter of (6.09 ± 1.58) mm (range from 3 to 9 mm)measured by left ventriculography. The diameter of occluder was (9.18 ± 2.79) mm (range from 8 to 12 mm). Complete closure of the defect was obtained in 10 cases, and another small residual shunt still remained in one case who had four outlets been treated by 2 occluders. No aortic valvular regurgitation occured in all patients except 1 patient presented complete atrioventricular block within 3 days after the procedure and recovered 2 weeks later with intravenous steroids therapy; and no other complications occured. The fluoroscopy time was(16.91 ± 4.23) min (range from 8 to 30 min). During follow-up from 1 m - 4 y, only 1 case showed residual shunt, and the other had no episodes of endocarditis, thromboembolism, hemolysis, infectious endocarditis, displacement of the occluder and aortic valvular regurgitation. Conclusion: Transcatheter closure of postoperative ventricular septal residual left-to-right shunt with China made-nitinol occluder is safe and effective. (authors)

Clinical-radiological evaluation of sequelae of stereotactic radiosurgery for intracranial arteriovenous malformations

International Nuclear Information System (INIS)

Levy, R.P.; Fabrikant, J.I.; Frankel, K.A.; Phillips, M.H.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.

1989-12-01

Stereotactic heavy-charged-particle Bragg peak radiosurgery has been used to treat 322 patients with surgically-inaccessible intracranial vascular malformations. (The clinical results of this method for the treatment of angiographically demonstrable arteriovenous malformations (AVMs) and angiographically occult vascular malformations (AOVMs) of the brain are described in separate reports of this symposium). The great majority of patients have had an uneventful post-treatment course with satisfactory health outcomes. However, several categories of delayed sequelae of stereotactic radiosurgery have been identified, involving the vascular structures essential for the integrity of the brain tissue and the brain parenchyma directly. These categories reflect both reaction to injury and to alterations in regional hemodynamic status, and include vasogenic edema, occlusion of functional vasculature, radiation necrosis, and local or remote effects on cerebral arterial aneurysms. 10 refs., 7 figs., 1 tab

Clinical-radiological evaluation of sequelae of stereotactic radiosurgery for intracranial arteriovenous malformations

Energy Technology Data Exchange (ETDEWEB)

Levy, R.P.; Fabrikant, J.I.; Frankel, K.A.; Phillips, M.H.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.

1989-12-01

Stereotactic heavy-charged-particle Bragg peak radiosurgery has been used to treat 322 patients with surgically-inaccessible intracranial vascular malformations. (The clinical results of this method for the treatment of angiographically demonstrable arteriovenous malformations (AVMs) and angiographically occult vascular malformations (AOVMs) of the brain are described in separate reports of this symposium). The great majority of patients have had an uneventful post-treatment course with satisfactory health outcomes. However, several categories of delayed sequelae of stereotactic radiosurgery have been identified, involving the vascular structures essential for the integrity of the brain tissue and the brain parenchyma directly. These categories reflect both reaction to injury and to alterations in regional hemodynamic status, and include vasogenic edema, occlusion of functional vasculature, radiation necrosis, and local or remote effects on cerebral arterial aneurysms. 10 refs., 7 figs., 1 tab.

Radiologic follow-up of the transjugular intrahepatic stent-shunt (TIPSS)

International Nuclear Information System (INIS)

Hansmann, H.J.; Noeldge, G.; Leutloff, U.; Radeleff, B.; Richter, G.M.

2001-01-01

The transjugular intrahepatic stent-shunt (TIPSS) is a well accepted minimal invasive therapy for complications of portal hypertension: recurrent variceal bleeding, refractory ascites and liver failure due to the Budd-Chiari syndrome. The high frequency of shunt stenoses and occlusions makes regular follow up examinations essential. Despite modern non invasive imaging methods direct portography still is the gold standard for shunt surveillance in TIPSS. Ultrasound is helpful to detect shunt dysfunction, but nevertheless its failure rate is considerable despite the use of contrast enhancers such as Levovist because of anatomic and physical limitations, particularly when TIPSS-tracts deep in the liver are present. Reintervention rates approach 90-100% after 24 months, with 100% in child's A patients with comparatively good liver function. However, a strict shunt surveillance program with early portography and reintervention when necessary guarantees high clinical success rates associated with very low rebleeding rates below 10%. Overall the secondary success rate is 80%. Secondary failures are mainly caused by lack of patient compliance during follow-up. In a subgroup of patients no shunt maturation is observed, requiring multiple shunt revisions. In cases of recurrent shunt occlusions an association with bile leaks is presumed. In selected cases patients with chronically recurrent shunt stenosis or occlusions may benefit from placement of TIPSS stent grafts. (orig.) [de

Lower rates of symptom recurrence and surgical revision after primary compared with secondary endoscopic third ventriculostomy for obstructive hydrocephalus secondary to aqueductal stenosis in adults.

Science.gov (United States)

Sankey, Eric W; Goodwin, C Rory; Jusué-Torres, Ignacio; Elder, Benjamin D; Hoffberger, Jamie; Lu, Jennifer; Blitz, Ari M; Rigamonti, Daniele

2016-05-01

OBJECT Endoscopic third ventriculostomy (ETV) is the treatment of choice for obstructive hydrocephalus; however, the success of ETV in patients who have previously undergone shunt placement remains unclear. The present study analyzed 103 adult patients with aqueductal stenosis who underwent ETV for obstructive hydrocephalus and evaluated the effect of previous shunt placement on post-ETV outcomes. METHODS This study was a retrospective review of 151 consecutive patients who were treated between 2007 and 2013 with ETV for hydrocephalus. One hundred three (68.2%) patients with aqueductal stenosis causing obstructive hydrocephalus were included in the analysis. Postoperative ETV patency and aqueductal and cisternal flow were assessed by high-resolution, gradient-echo MRI. Post-ETV Mini-Mental State Examination, Timed Up and Go, and Tinetti scores were compared with preoperative values. Univariate and multivariate analyses were performed comparing the post-ETV outcomes in patients who underwent a primary (no previous shunt) ETV (n = 64) versus secondary (previous shunt) ETV (n = 39). RESULTS The majority of patients showed significant improvement in symptoms after ETV; however, no significant differences were seen in any of the quantitative tests performed during follow-up. Symptom recurrence occurred in 29 (28.2%) patients after ETV, after a median of 3.0 (interquartile range 0.8-8.0) months post-ETV failure. Twenty-seven (26.2%) patients required surgical revision after their initial ETV. Patients who received a secondary ETV had higher rates of symptom recurrence (p = 0.003) and surgical revision (p = 0.003), particularly in regard to additional shunt placement/revision post-ETV (p = 0.005). These differences remained significant after multivariate analysis for both symptom recurrence (p = 0.030) and surgical revision (p = 0.043). CONCLUSIONS Patients with obstructive hydrocephalus due to aqueductal stenosis exhibit symptomatic improvement after ETV, with a

Angiographic treatment of the arteriovenous malformation occurred after caesarean section

Directory of Open Access Journals (Sweden)

Selim Büyükkurt

2009-03-01

Full Text Available INTRODUCTION: Uterine arteriovenous malformations are classified as acquired or congenital. Caesarean section which is performed more frequently on nowadays, uterine curettage and other uterine surgeries are the most common causes of the acquired arteriovenous malformations. CASE: Twenty-two years old woman delivered her second child by caesarean section, due to history of caesarean section, was admitted with complaint of profuse vaginal bleeding 15 days after the surgery. She demonstrated the clinical features of the hypovolemic shock. At first she treated with four units of red blood suspension, two units of fresh frozen plasma and rapid infusion of the fluids. On endometrial curettage only blood and coagulum were obtained. The bleeding could only be controlled by the internal pressure of the 18 F Foley catheter. Doppler analyze of the uterus revealed a vascular malformation signifying a turbulent flow pattern with low pressure and high flow rate. A unilateral uterine artery embolization was performed her and her menstruel cycles are resumed at the fifth month of the puerperium. DISCUSSION: The clinical presentation of the uterine arteriovenous malformations depends on the localization and the dimensions of the malformation. The uterine arteriovenous malformation should be kept in mind in cases of late occurrence vaginal bleeding unresponsive to the uterotonic medications, especially in a woman with previous history of uterine damage, such as curettage or caesarean section.

Resident-performed Ex-PRESS shunt implantation versus trabeculectomy.

Science.gov (United States)

Seider, Michael I; Rofagha, Soraya; Lin, Shan C; Stamper, Robert L

2012-09-01

To compare outcomes between resident-performed trabeculectomy and Ex-PRESS shunt implantation. A consecutive cohort of 36 Ex-PRESS shunt implantations and 57 trabeculectomies (1 eye/patient) performed by resident surgeons in their third year of ophthalmic training at the University of California, San Francisco and at the San Francisco Veterans Administration Hospital, under the supervision of a single glaucoma fellowship-trained surgeon were included in this study. Eyes with PRESS shunt groups at all follow-up points. On average, the Ex-PRESS shunt group required significantly less ocular antihypertensive medication to control IOP at 3 months postoperative (P=0.01), but no difference was found at 6 months or 1 year (all, P≥0.28). A larger proportion of Ex-PRESS shunt patients had good IOP control without medication at 3 (P=0.057) and 6 months (P=0.076) postoperatively. No difference was found in the rates of sight-threatening complications between groups (all, P≥0.22). In the hands of ophthalmology residents in their third year of training, the trabeculectomy and Ex-PRESS shunt implantation procedures perform comparably in terms of postoperative IOP control, reduction in patient dependence on ocular antihypertensive medications, and risk of complication in our population.

Investigating PID Shunting in Polycrystalline Silicon Modules via Multiscale, Multitechnique Characterization

Energy Technology Data Exchange (ETDEWEB)

Harvey, Steven P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Moseley, John [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Norman, Andrew [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hacke, Peter L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Johnston, Steven [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Al-Jassim, Mowafak M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Stokes, Adam [Colorado School of Mines; Gorman, Brian [Colorado School of Mines

2018-02-27

We investigated the potential-induced degradation (PID) shunting mechanism in multicrystalline-silicon photovoltaic modules by using a multiscale, multitechnique characterization approach. Both field-stressed modules and laboratory-stressed mini modules were studied. We used photoluminescence, electroluminescence, and dark lock-in thermography imaging to identify degraded areas at the module scale. Small samples were then removed from degraded areas, laser marked, and imaged by scanning electron microscopy. We used simultaneous electron-beam induced current imaging and focused ion beam milling to mark around PID shunts for chemical analysis by time-of-flight secondary-ion mass spectrometry or to isolate individual shunt defects for transmission electron microscopy and atom-probe tomography analysis. By spanning a range of 10 orders of magnitude in size, this approach enabled us to investigate the root-cause mechanisms for PID shunting. We observed a direct correlation between recombination active shunts and sodium content. The sodium content in shunted areas peaks at the SiNX/Si interface and is consistently observed at a concentration of 0.1% to 2% in shunted areas. Analysis of samples subjected to PID recovery, either activated by electron beam or thermal effects only, reveals that recovery of isolated shunts correlates with diffusion of sodium out of the structural defects to the silicon surface. We observed the role of oxygen and chlorine in PID shunting and found that those species - although sometimes present in structural defects where PID shunting was observed - do not play a consistent role in PID shunting.

Assessment Lumboperitoneal or Ventriculoperitoneal Shunt Patency by Radionuclide Technique: A Review Experience Cases

International Nuclear Information System (INIS)

Chiewvit, Sunanta; Nuntaaree, Sarun; Kanchaanapiboon, Potjanee; Chiewvit, Pipat

2014-01-01

Hydrocephalus-related symptoms that worsen after shunt placement may indicate a malfunctioning or obstructed shunt. The assessment of shunt patency and site of obstruction is important for planning of treatment. The radionuclide cerebrospinal fluid (CSF) shunt study provides a simple, effective, and low-radiation-dose method of assessing CSF shunt patency. The radionuclide CSF shuntography is a useful tool in the management of patients presenting with shunt-related problems not elucidated by conventional radiological examination. This article described the imaging technique of ventriculoperitoneal (VP) shunt and lumbar puncture (LP) shunt. The normal finding, abnormal finding of completed obstruction and partial obstruction is present by our cases experience. The radiopharmaceutical (Tc-99m diethylenetriaminepentaacetic acid) was injected via the reservoir for VP shunt and via lumbar puncture needle in subarachnoid space for LP shunt, then serial image in the head and abdominal area. The normal function of VP and LP shunt usually rapid spillage of the radioactivity in the abdominal cavity diffusely. The patent proximal tube VP shunt demonstrates ventricular reflux. The early image of patent LP shunt reveals no activity in the ventricular system contrast to distal LP shunt reveals early reflux of activity in the ventricular system. The completed distal VP and LP shunt obstruction show absence of tracer in the peritoneal area or markedly delayed appearance of abdominal activity. The partial distal VP and LP shunt obstruction recognized by slow transit or accumulation of tracer at the distal end or focal tracer in the peritoneal cavity near the tip of distal shunt. The images of the normal and abnormal CSF shunt as describe before are present in the full paper. Radionuclide CSF shuntography is a reliable and simple procedure for assessment shunt patency

Vector Volume Flow in Arteriovenous Fistulas

DEFF Research Database (Denmark)

Hansen, Peter Møller; Heerwagen, Søren; Pedersen, Mads Møller

2013-01-01

, but is very challenging due to the angle dependency of the Doppler technique and the anatomy of the fistula. The angle independent vector ultrasound technique Transverse Oscillation provides a new and more intuitive way to measure volume flow in an arteriovenous fistula. In this paper the Transverse...

Hydrocephalus and Shunts

Science.gov (United States)

... of a problem. Because of the complexity, a neurosurgeon is the best person to diagnosis and treat ... type of shunt is best for whom. So neurosurgeons usually pick ones that they think are best. ...

Adventitial transduction of lentivirus-shRNA-VEGF-A in arteriovenous fistula reduces venous stenosis formation.

Science.gov (United States)

Yang, Binxia; Janardhanan, Rajiv; Vohra, Pawan; Greene, Eddie L; Bhattacharya, Santanu; Withers, Sarah; Roy, Bhaskar; Nieves Torres, Evelyn C; Mandrekar, Jaywant; Leof, Edward B; Mukhopadhyay, Debabrata; Misra, Sanjay

2014-02-01

Venous neointimal hyperplasia (VNH) causes hemodialysis vascular access failure. Here we tested whether VNH formation occurs in part due to local vessel hypoxia caused by surgical trauma to the vasa vasorum of the outflow vein at the time of arteriovenous fistula placement. Selective targeting of the adventitia of the outflow vein at the time of fistula creation was performed using a lentivirus-delivered small-hairpin RNA that inhibits VEGF-A expression. This resulted in significant increase in mean lumen vessel area, decreased media/adventitia area, and decreased constrictive remodeling with a significant increase in apoptosis (increase in caspase 3 activity and TUNEL staining) accompanied with decreased cellular proliferation and hypoxia-inducible factor-1α at the outflow vein. There was significant decrease in cells staining positive for α-smooth muscle actin (a myofibroblast marker) and VEGFR-1 expression with a decrease in MMP-2 and MMP-9. These results were confirmed in animals that were treated with humanized monoclonal antibody to VEGF-A with similar results. Since hypoxia can cause fibroblast to differentiate into myofibroblasts, we silenced VEGF-A gene expression in fibroblasts and subjected them to hypoxia. This decreased myofibroblast production, cellular proliferation, cell invasion, MMP-2 activity, and increased caspase 3. Thus, VEGF-A reduction at the time of arteriovenous fistula placement results in increased positive vascular remodeling.

Atypical MRI features in soft-tissue arteriovenous malformation: a novel imaging appearance with radiologic-pathologic correlation

Energy Technology Data Exchange (ETDEWEB)

Patel, Anand S. [University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); University of California, San Francisco, Department of Interventional Radiology, San Francisco, CA (United States); Schulman, Joshua M.; Ruben, Beth S. [University of California, San Francisco, Departments of Pathology and Dermatology, San Francisco, CA (United States); Hoffman, William Y. [University of California, San Francisco, Department of Plastic Surgery, Birthmarks and Vascular Anomalies Clinic, San Francisco, CA (United States); Dowd, Christopher F. [University of California, San Francisco, Department of Interventional Neuroradiology, Birthmarks and Vascular Anomalies Clinic, San Francisco, CA (United States); Frieden, Ilona J. [University of California, San Francisco, Department of Dermatology, Birthmarks and Vascular Anomalies Clinic, San Francisco, CA (United States); Hess, Christopher P. [University of California, San Francisco, Department of Neuroradiology, Birthmarks and Vascular Anomalies Clinic, San Francisco, CA (United States)

2015-09-15

The absence of a discrete mass, surrounding signal abnormality and solid enhancement are imaging features that have traditionally been used to differentiate soft-tissue arteriovenous malformations from vascular tumors on MRI. We have observed that these findings are not uncommon in arteriovenous malformations, which may lead to misdiagnosis or inappropriate treatment. To estimate the frequency of atypical MRI features in soft-tissue arteriovenous malformations and assess their relationship to lesion size, location, tissue type involved and vascular architecture. Medical records, MRI and histopathology were reviewed in consecutive patients with soft-tissue arteriovenous malformations in a multidisciplinary vascular anomalies clinic. Arteriovenous malformations were divided into those with and without atypical MRI findings (perilesional T2 signal abnormality, enhancement and/or a soft-tissue mass). Lesion location, size, tissue involved and vascular architecture were also compared between groups. Tissue stains were reviewed in available biopsy or resection specimens to assess relationships between MRI findings and histopathology. Thirty patients with treatment-naive arteriovenous malformations were included. Fifteen lesions demonstrated atypical MRI. There was no difference in age, gender, lesion size or involved body part between the groups. However, more than half of the atypical lesions demonstrated multicompartmental involvement, and tiny intralesional flow voids were more common in atypical arteriovenous malformations. Histopathology also differed in atypical cases, showing densely packed endothelial cells with connective tissue architectural distortion and edema. Arteriovenous malformations may exhibit features of a vascular tumor on MRI, particularly when multicompartmental and/or containing tiny internal vessels. These features are important to consider in suspected fast-flow vascular malformations and may have implications with respect to their treatment

Cross-species functionality of pararetroviral elements driving ribosome shunting.

Directory of Open Access Journals (Sweden)

Mikhail M Pooggin

Full Text Available BACKGROUND: Cauliflower mosaic virus (CaMV and Rice tungro bacilliform virus (RTBV belong to distinct genera of pararetroviruses infecting dicot and monocot plants, respectively. In both viruses, polycistronic translation of pregenomic (pg RNA is initiated by shunting ribosomes that bypass a large region of the pgRNA leader with several short (sORFs and a stable stem-loop structure. The shunt requires translation of a 5'-proximal sORF terminating near the stem. In CaMV, mutations knocking out this sORF nearly abolish shunting and virus viability. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that two distant regions of the CaMV leader that form a minimal shunt configuration comprising the sORF, a bottom part of the stem, and a shunt landing sequence can be replaced by heterologous sequences that form a structurally similar configuration in RTBV without any dramatic effect on shunt-mediated translation and CaMV infectivity. The CaMV-RTBV chimeric leader sequence was largely stable over five viral passages in turnip plants: a few alterations that did eventually occur in the virus progenies are indicative of fine tuning of the chimeric sequence during adaptation to a new host. CONCLUSIONS/SIGNIFICANCE: Our findings demonstrate cross-species functionality of pararetroviral cis-elements driving ribosome shunting and evolutionary conservation of the shunt mechanism. We are grateful to Matthias Müller and Sandra Pauli for technical assistance. This work was initiated at Friedrich Miescher Institute (Basel, Switzerland. We thank Prof. Thomas Boller for hosting the group at the Institute of Botany.

Predicting ventriculoperitoneal shunt infection in children with hydrocephalus using artificial neural network.

Science.gov (United States)

Habibi, Zohreh; Ertiaei, Abolhasan; Nikdad, Mohammad Sadegh; Mirmohseni, Atefeh Sadat; Afarideh, Mohsen; Heidari, Vahid; Saberi, Hooshang; Rezaei, Abdolreza Sheikh; Nejat, Farideh

2016-11-01

The relationships between shunt infection and predictive factors have not been previously investigated using Artificial Neural Network (ANN) model. The aim of this study was to develop an ANN model to predict shunt infection in a group of children with shunted hydrocephalus. Among more than 800 ventriculoperitoneal shunt procedures which had been performed between April 2000 and April 2011, 68 patients with shunt infection and 80 controls that fulfilled a set of meticulous inclusion/exclusion criteria were consecutively enrolled. Univariate analysis was performed for a long list of risk factors, and those with p value < 0.2 were used to create ANN and logistic regression (LR) models. Five variables including birth weight, age at the first shunting, shunt revision, prematurity, and myelomeningocele were significantly associated with shunt infection via univariate analysis, and two other variables (intraventricular hemorrhage and coincided infections) had a p value of less than 0.2. Using these seven input variables, ANN and LR models predicted shunt infection with an accuracy of 83.1 % (AUC; 91.98 %, 95 % CI) and 55.7 % (AUC; 76.5, 95 % CI), respectively. The contribution of the factors in the predictive performance of ANN in descending order was history of shunt revision, low birth weight (under 2000 g), history of prematurity, the age at the first shunt procedure, history of intraventricular hemorrhage, history of myelomeningocele, and coinfection. The findings show that artificial neural networks can predict shunt infection with a high level of accuracy in children with shunted hydrocephalus. Also, the contribution of different risk factors in the prediction of shunt infection can be determined using the trained network.

Bacterial contamination of surgeons' gloves during shunt insertion; a pilot study

DEFF Research Database (Denmark)

Sørensen, Preben; Ejlertsen, Tove; Aaen, Dorte

2008-01-01

Bacterial infection is a major cause of shunt dysfunction. It is well-known that the majority of pathogenic micro-organisms are low-virulent bacteria normally found on intact skin. Probably shunts become contaminated during surgery either by contact to the patient skin, or contact from contaminated...... gloves or instruments. This study was performed to find out to what extent gloves become contaminated during shunt surgery. Gloves used during shunt implantation were examined in 10 operations. Shunt implantation was done using recommended precautions to avoid infection, including prophylactic...... nurse and assistant were contaminated with micro-organisms less than 15 min after surgery has been commenced and before the shunts were handled. This study offers a feasible, simple and logical explanation of how shunts may become contaminated and infected. A simple measure would be to change the outer...

Experience and outcome of ventricular-atrial shunt: a multi centre study

International Nuclear Information System (INIS)

Akhtar, N.; Khan, A.A.; Yousaf, M.

2015-01-01

Ventriculoperitoneal (VP) shunt has been widely utilized in the treatment of hydrocephalus as a safe option but there is recent literature evidence that ventricularatrial (VA) shunt is not as notorious for its complications as proclaimed, to analyse and report our success with this procedure we conducted our study. Methods: A total of 64 patients undergoing VA shunting were included in this case series study conducted at RMC and Allied hospital Rawalpindi. The data was collected over a period of 4 years from, 1st June 2010 to 1st June 2015. Result: Our study included 64 patients who underwent a VA shunt for hydrocephalus. Their age ranged from 25 to 75 years. Most of the patients were females (60%). The following complications were observed with 2 (3.12%) patients having blockage of the shunt at the neck, 3 (4.68%) suffered from glomerulonephritis, 2 (3.1%) had post-operative neck hematoma, 4 (6.25 %) had wound infection, short lower end of the tube was found in 3 (4.68%), migrated lower end (into the subclavian) was seen in 1 (1.56%). Mortality was 1(1.56%). These results were comparable to other studies. Conclusion: Neurosurgeons have been doing a VA shunt as a second procedure, after a VP shunt when the need due to a complication was encountered. We however share our experience regarding ventriculo-atrial shunting, as first choice procedure, because of its low incidence of shunt blockage unlike VP shunt, which has high rate of shunt blockage and therefore warrants repeated surgeries. (author)

Shunt attachment and method for interfacing current collection systems

Science.gov (United States)

Denney, Paul E.; Iyer, Natraj C.; Hannan, III, William F.

1992-01-01

A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature.

Vibration damping with negative capacitance shunts: theory and experiment

International Nuclear Information System (INIS)

De Marneffe, B; Preumont, A

2008-01-01

This paper analyzes in detail the enhancement of piezoelectric stack transducers by means of the well known 'negative' capacitive shunting. The stability is thoroughly studied: starting from the electrical admittance curve of the transducer, a method is introduced that quantifies the stability margins of the shunted structure. Two different implementations (series vs parallel) are investigated, and the lack of robustness of the parallel one is demonstrated. Next, this technique is experimentally applied on a truss structure. Its performances are compared with those of passive shunt circuits and with those of an active control law, the so-called Integral Force Feedback or IFF. As expected, the damping introduced by the negative capacitance shunt is larger than the damping obtained with the passive shunts; it remains, however, one order of magnitude smaller than that obtained with the IFF

Microsurgical resection of incompletely obliterated intracranial arteriovenous malformations following stereotactic radiosurgery

International Nuclear Information System (INIS)

Chang, S.D.; Steinberg, G.K.; Levy, R.P.; Marks, M.P.; Frankel, K.A.; Shuster, D.L.; Marcellus, M.L.

1998-01-01

Radiosurgery is effective in obliterating small arteriovenous malformations (AVMs), but less successful in thrombosing larger AVMs. This study reviewed patients who underwent surgical resection of their large AVMs following failed radiosurgical obliteration. AVMs from 36 patients (aged 7 to 64 years, mean 29.9) were surgically resected 1 to 11 years after radiosurgery. Initial AVM volumes were 0.7 to 117 cm 3 (mean 21.6 cm 3 ), and radiosurgical doses ranged from 4.6 to 45 Gray equivalent (GyE) (mean 21.1 GyE). Thirty AVMs (83%) were located in eloquent tissue. Venous drainage was deep (14), superficial (13), or both (9). Spetzler grades were II (2), III (12), IV (18), and V (4). Nine patients suffered rehemorrhage after radiosurgery but prior to surgery, while three patients developed radiation necrosis. Twenty-seven patients underwent endovascular embolization prior to surgery. During microsurgical resection, the AVMs were found to be significantly less vascular and more easily resected, compared to AVMs in patients who had not received radiosurgery. Histology showed endothelial proliferation with hyaline and mineralization in vessel walls. Partial or complete thrombosis of some AVM vessels, and evidence of vessel and brain necrosis were noted in many cases. Clinical outcome was excellent or good in 34 cases, with two patients dying of rebleeding from residual AVM. Five patients were neurologically worse following microsurgical resection. Final outcome was largely related to the pretreatment grade. Radiosurgery several years prior to surgical resection appears useful in treating unusually large and complex AVMs. (author)

Penile artery shunt syndrome: a novel cause of erectile dysfunction after penile revascularization surgery.

Science.gov (United States)

Pavlinec, Jonathan G; Hakky, Tariq S; Yang, Christopher; Massis, Kamal; Munarriz, Ricardo; Carrion, Rafael E

2014-09-01

Penile revascularization is a surgical treatment option for erectile dysfunction (ED) in healthy individuals due to a focal arterial occlusion in the absence of generalized vascular disease. Most described failures have been attributed to graft stenosis or disruption of the anastomosis. We report a novel phenomenon called Penile Artery Shunt Syndrome that contributed to persistent ED in a patient after penile microvascular arterial bypass surgery. A 26-year-old man presented for evaluation of long-standing ED, which was attributed to trauma sustained 12 years earlier. He had difficulty obtaining and maintaining erections despite oral pharmacotherapy. Clinical data related to the case were studied, analyzed, and reviewed with urologic and radiologic specialists at multiple centers that collaborated in the care of this patient. Penile duplex ultrasound peak systolic velocities and five-item International Index for Erectile Function questionnaire scores were the main outcome measures. Initial diagnostic workup of the patient confirmed severe insufficiency of the left cavernosal artery, with no evidence of venous leak. The patient underwent penile microvascular arterial bypass surgery with anastomosis of the left inferior epigastric artery to the left dorsal penile artery. The patient had persistence of severe ED despite patent anastomosis by penile duplex ultrasound. Subsequent arteriography revealed an arterial shunt due to an aberrant obturator artery arising from the donor inferior epigastric artery. The patient underwent embolization of the aberrant obturator artery, with resolution of the shunt and marked improvement in erectile function. The presence of an aberrant obturator artery arising from the inferior epigastric artery may predispose to persistent ED after revascularization due to the creation of a shunt phenomenon. Pelvic arteriography may be useful in identifying anomalous anatomic considerations prior to penile revascularization and to evaluate patients

Arteriovenous Malformation Detected by Small Bowel Endoscopy

Directory of Open Access Journals (Sweden)

Takaaki Fujii

2014-10-01

Full Text Available Gastrointestinal bleeding that originates in the small intestine is often difficult to diagnose. When successful diagnosis reveals a lesion that can be localized preoperatively, the laparoscopic approach is an appropriate and beneficial treatment modality for small bowel resection. A 69-year-old man presented with a 6-month history of gastrointestinal bleeding and symptomatic transfusion-dependent anemia. Upper and lower endoscopy were normal. Double-balloon endoscopy established the source of the bleeding as a 0.5-cm polypoid mass appearing as a submucosal tumor with redness and pulsation in the lower ileum, suggesting a vascular lesion. Laparoscopic small bowel resection was successful in removing the mass in the ileum. Histological evaluation of the mass revealed an arteriovenous malformation. Preoperative small bowel endoscopy can be useful for diagnosing the cause and localization of arteriovenous malformation in the small intestine.

Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

Science.gov (United States)

Kim, Brian J; Jin, Willa; Baldwin, Alexander; Yu, Lawrence; Christian, Eisha; Krieger, Mark D; McComb, J Gordon; Meng, Ellis

2016-10-01

Neurosurgical ventricular shunts inserted to treat hydrocephalus experience a cumulative failure rate of 80 % over 12 years; obstruction is responsible for most failures with a majority occurring at the proximal catheter. Current diagnosis of shunt malfunction is imprecise and involves neuroimaging studies and shunt tapping, an invasive measurement of intracranial pressure and shunt patency. These patients often present emergently and a delay in care has dire consequences. A microelectromechanical systems (MEMS) patency sensor was developed to enable direct and quantitative tracking of shunt patency in order to detect proximal shunt occlusion prior to the development of clinical symptoms thereby avoiding delays in treatment. The sensor was fabricated on a flexible polymer substrate to eventually allow integration into a shunt. In this study, the sensor was packaged for use with external ventricular drainage systems for clinical validation. Insights into the transduction mechanism of the sensor were obtained. The impact of electrode size, clinically relevant temperatures and flows, and hydrogen peroxide (H2O2) plasma sterilization on sensor function were evaluated. Sensor performance in the presence of static and dynamic obstruction was demonstrated using 3 different models of obstruction. Electrode size was found to have a minimal effect on sensor performance and increased temperature and flow resulted in a slight decrease in the baseline impedance due to an increase in ionic mobility. However, sensor response did not vary within clinically relevant temperature and flow ranges. H2O2 plasma sterilization also had no effect on sensor performance. This low power and simple format sensor was developed with the intention of future integration into shunts for wireless monitoring of shunt state and more importantly, a more accurate and timely diagnosis of shunt failure.

New and improved ways to treat hydrocephalus: Pursuit of a smart shunt.

Science.gov (United States)

Lutz, Barry R; Venkataraman, Pranav; Browd, Samuel R

2013-01-01

The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a "smart shunt" that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care.

Lower Limb Arteriovenous Communications in Diabetes Mellitus: A Potential Reason for Aggravation of Ischemic Symptoms

International Nuclear Information System (INIS)

Hamady, Mohamad S.; Yu, Dominic F.; Sayer, Gabriel L.; Edmonds, Michael E.; Walters, Huw L.; Sidhu, Paul S.

2006-01-01

The aim of this study was to assess the prevalence and to evaluate the clinical associations of arteriovenous communications in patients with diabetes mellitus (DM) and lower limb peripheral arterial ischemia. Peripheral arteriography of DM patients from an eight-year period (1993-2000) was evaluated retrospectively by two observers. The presence of arteriovenous communications, defined as occurring without evidence of a preceding precipitating event, and the distribution and severity of the vascular disease were evaluated. The type (non-insulin-dependent DM or insulin-dependent DM) and the duration of the DM, the presenting symptoms, and the presence of a peripheral neuropathy were documented by a review of the clinical records. A total of 348 arteriography studies in 285 DM patients were evaluated (duration of DM: median, 16 years; range, 7-42 years); an arteriovenous communication was present in 14/285 patients (4.9%), 9 male and 5 female (median age, 71 years; range, 17-84 years). Symptoms were those of a peripheral leg ulcer (n = 11), claudication (n = 3), and gangrene (n = 1), with symptoms ipsilateral to the side of the arteriovenous communication in 13/14 patients. The sites of the arteriovenous communications were infra popliteal (n = 7), popliteal (n = 3), superficial femoral artery (n = 3), and common femoral artery (n = 1). Features of a peripheral neuropathy were found in 12/14 and ipsilateral to the side of the communication in 11/12. Arteriovenous communications in the peripheral femoral arterial system of patients with DM is an uncommon finding. Although not proven in the current study, arteriovenous communications might be associated with more severe symptoms than that attributable to the underlying vascular disease alone

Coupling slots without shunt impedance drop

International Nuclear Information System (INIS)

Balleyguier, P.

1996-01-01

It is well known that coupling slots between adjacent cells in a π-mode structure reduce shunt impedance per unit length with respect to single cell cavities. To design optimized coupling slots, one has to answer the following question: for a given coupling factor, what shape, dimension, position and number of slots lead to the lowest shunt impedance drop? A numerical study using the 3D code MAFIA has been carried out. The aim was to design the 352 MHz cavities for the high intensity proton accelerator of the TRISPAL project. The result is an unexpected set of four 'petal' slots. Such slots should lead to a quasi-negligible drop in shunt impedance: about -1% on average, for particle velocity from 0.4 c to 0.8 c. (author)

Shoulder tip pain: an under-reported complication of ventriculoperitoneal shunt.

LENUS (Irish Health Repository)

Lim, C

2012-02-03

Ventriculoperitoneal (VP) shunt insertion is the commonest form of treatment for hydrocephalus. Shoulder tip pain after VP shunt insertion is unusual and has only recently been reported. We present a case of excruciating shoulder tip pain due to diaphragmatic irritation after VP shunt insertion.

Programmable shunts and headphones: Are they safe together?

Science.gov (United States)

Spader, Heather S; Ratanaprasatporn, Linda; Morrison, John F; Grossberg, Jonathan A; Cosgrove, G Rees

2015-10-01

Programmable shunts have a valuable role in the treatment of patients with hydrocephalus, but because a magnet is used to change valve settings, interactions with external magnets may reprogram these shunts. Previous studies have demonstrated the ability of magnetic toys and iPads to erroneously reprogram shunts. Headphones are even more ubiquitous, and they contain an electromagnet for sound projection that sits on the head very close to the shunt valve. This study is the first to look at the magnetic field emissions of headphones and their effect on reprogrammable shunt valves to ascertain whether headphones are safe for patients with these shunts to wear. In this in vitro study of the magnetic properties of headphones and their interactions with 3 different programmable shunts, the authors evaluated Apple earbuds, Beats by Dr. Dre, and Bose QuietComfort Acoustic Noise Cancelling headphones. Each headphone was tested for electromagnetic field emissions using a direct current gaussmeter. The following valves were evaluated: Codman Hakim programmable valve, Medtronic Strata II valve, and Aesculap proGAV. Each valve was tested at distances of 0 to 50 mm (in 5-mm increments) from each headphone. The exposure time at each distance was 1 minute, and 3 trials were performed to confirm results at each valve setting and distance. All 3 headphones generated magnetic fields greater than the respective shunt manufacturer's recommended strength of exposure, but these fields did not persist beyond 5 mm. By 2 cm, the fields levels were below 20 G, well below the Medtronic recommendation of 90 G and the Codman recommendation of 80 G. Because the mechanism for the proGAV is different, there is no recommended gauss level. There was no change in gauss-level emissions by the headphones with changes in frequency and amplitude. Both the Strata and Codman-Hakim valves were reprogrammed by direct contact (distance 0 mm) with the Bose headphones. When a rotation component was added, all

Optimization methods for the Train Unit Shunting Problem

DEFF Research Database (Denmark)

Haahr, Jørgen Thorlund; Lusby, Richard Martin; Wagenaar, Joris Camiel

2017-01-01

We consider the Train Unit Shunting Problem, an important planning problem for passenger railway operators. This problem entails assigning train units from shunting yards to scheduled train services in such a way that the resulting operations are without conflicts. The problem arises at every...... shunting yard in the railway network and involves matching train units to arriving and departing train services as well as assigning the selected matchings to appropriate shunting yard tracks. We present an extensive comparison benchmark of multiple solution approaches for this problem, some of which...... are novel. In particular, we develop a constraint programming formulation, a column generation approach, and a randomized greedy heuristic. We compare and benchmark these approaches with two existing methods, a mixed integer linear program and a two-stage heuristic. The benchmark contains multiple real...

Intravenous digital subtraction angiography in the assessment of patients with left to right shunts before and after surgical correction

International Nuclear Information System (INIS)

Yiannikas, J.; Moodie, D.S.; Gill, C.C.; Sterba, R.; McIntyre, R.; Buonocore, E.

1984-01-01

Pre- and postoperative structural changes and pulmonary to systemic flow (QP/QS) ratios were assessed using digital angiography in 34 patients documented to have a left to right shunt at cardiac catheterization. There were 16 men and 18 women whose ages ranged from 4 months to 60 years. The radiographic single mask mode was used for all digital subtraction angiographic studies with a typical radiographic sequence being 80 to 100 kV, 5 to 10 mA/frame at six frames/s for 15 seconds. Renografin-76 was used as a bolus injection at 0.5 to 1.0 ml/kg via an arm vein in most patients. The level of the left to right shunt and any associated anomalies were noted and compared with results from cardiac catheterization. Digital subtraction angiographic flow curves were generated from the pulmonary arteries, and QP/QS ratios were calculated pre- and postoperatively using the gamma variate fit method and compared with the QP/QS ratio from first pass radionuclide studies. A strong correlation between preoperative digital subtraction angiographically derived QP/QS ratio and radionuclide-derived QP/QS ratio was found, with an r value equal to 0.89, p less than 0.0001. Postoperatively, all patients had a QP/QS ratio less than 1.2:1.0 for both digital subtraction angiography and radionuclide studies. The level of left to right shunt was accurately assessed in all patients, and its absence observed postoperatively. Associated anomalies, such as a persistent left superior vena cava, coarctation of the aorta and partial anomalous venous return, were identified in all cases

Improvement of cerebral hypometabolism after resection of radiation-induced necrotic lesion in a patient with cerebral arteriovenous malformation

International Nuclear Information System (INIS)

Harada, Yae; Hirata, Kenji; Nakayama, Naoki; Yamaguchi, Shigeru; Yoshida, Michiharu; Onodera, Shunsuke; Manabe, Osamu; Shiga, Tohru; Terae, Satoshi; Shirato, Hiroki; Tamaki, Nagara

2015-01-01

A 55-year-old woman underwent radiosurgery for a left cerebral hemisphere arteriovenous malformation (AVM) and developed radiation-induced necrosis causing a massive edema in the surrounding brain tissues. Despite various therapies, the edema expanded to the ipsilateral hemisphere and induced neurological symptoms. The radiation-induced necrotic lesion was surgically removed 4 years after radiosurgery. While the preoperative FDG PET revealed severe hypometabolism in the left cerebrum, the necrotomy significantly ameliorated the brain edema, glucose metabolism (postoperative FDG PET), and symptoms. This case indicates that radiation necrosis-induced neurological deficits may be associated with brain edema and hypometabolism, which could be reversed by appropriate necrotomy

Liver Abscess Associated with Hepatic Artery Pseudoaneurysm with Arteriovenous Fistula: Imaging and Interventional Management

International Nuclear Information System (INIS)

Kang, M.; Bapuraj, J.R.; Khandelwal, N.; Kochhar, R.; Kalra, N.; Verma, G. R.

2006-01-01

Hepatic artery pseudoaneurysm is an infrequently encountered entity that is usually seen secondary to trauma or surgical procedures. The clinical presentation is often due to complications such as massive intrahepatic or intraperitoneal bleeding as a result of rupture of the pseudoaneurysm into the biliary tree or peritoneal cavity, respectively. Hepatic artery pseudoaneurysm, associated with a liver abscess, has very rarely been described in the literature. We present the imaging features of a case of liver abscess associated with a hepatic artery pseudoaneurysm and complicated by rupture and formation of an arteriovenous fistula. The case was successfully managed by percutaneous endovascular embolization. The association between a hepatic artery pseudoaneurysm and a liver abscess must not be overlooked, bearing in mind the potentially fatal associated complications which can be averted or treated by timely intervention

Liver Abscess Associated with Hepatic Artery Pseudoaneurysm with Arteriovenous Fistula: Imaging and Interventional Management

Energy Technology Data Exchange (ETDEWEB)

Kang, M.; Bapuraj, J.R.; Khandelwal, N.; Kochhar, R.; Kalra, N.; Verma, G. R. [Postgraduate Inst. of Medical Education and Research, Chandigarh (India). Depts. of Radiodiagnosis and General Surgery

2006-03-15

Hepatic artery pseudoaneurysm is an infrequently encountered entity that is usually seen secondary to trauma or surgical procedures. The clinical presentation is often due to complications such as massive intrahepatic or intraperitoneal bleeding as a result of rupture of the pseudoaneurysm into the biliary tree or peritoneal cavity, respectively. Hepatic artery pseudoaneurysm, associated with a liver abscess, has very rarely been described in the literature. We present the imaging features of a case of liver abscess associated with a hepatic artery pseudoaneurysm and complicated by rupture and formation of an arteriovenous fistula. The case was successfully managed by percutaneous endovascular embolization. The association between a hepatic artery pseudoaneurysm and a liver abscess must not be overlooked, bearing in mind the potentially fatal associated complications which can be averted or treated by timely intervention.

A treatment strategy for arteriovenous malformations of the brain based on results of gamma knife surgery experienced between 1991 and 1995

International Nuclear Information System (INIS)

Inoue, Hiroshi K.; Nagaseki, Yoshishige; Nishi, Hideo; Sanada, Tomoyuki; Tachikawa, Yuichi; Nishimatsu, Terutaka; Ohye, Chihiro; Andou, Yoshitaka; Naitou, Isao

2001-01-01

We investigated a treatment strategy for arteriovenous malformations (AVMs) of the brain based on results of 107 patients treated with Gamma Knife (GK) surgery between 1991 and 1995. Total obliteration was obtained in 80.5%. The obliteration rate was 82.1% in Grade 3 of Spetzler-Martin scale, 75.0% in Grade 4, 50.0% in Grade 5, and 66.7% in Grade 6. The obliteration rate of slow and low flow AVMs (moya type) within 12 months (65.5%) was significantly higher than that of rapid and/or high flow AVMs (shunt, mixed type). Six patients had bleeding 7 to 42 months after GK surgery. The annual rate of bleeding in accumulated years was 2.3%. Adverse effects appeared in 2 (1.9%) of 107 patients, and both patients had AVMs in the internal capsule. We concluded that microsurgery is recommended for AVMs operable without morbidity, and GK surgery is recommended for AVMs in functional areas, and that intravascular embolization is required for large, rapid and/or high flow AVMs, especially those with hemorrhagic risk factors. (author)

Vertebral Arteriovenous Fistula Presenting as Cervical Myelopathy: A Rapid Recovery with Balloon Embolization

International Nuclear Information System (INIS)

Modi, Manish; Bapuraj, J. Rajiv; Lal, Anupam; Prabhakar, S.; Khandelwal, N.

2010-01-01

A 24-year-old male presented with progressive cervical myelopathy of 2 months' duration. Magnetic resonance imaging of the cervical spine and angiography revealed a large arteriovenous fistula arising from the left vertebral artery. The present case highlights the clinical features and dramatic recovery following endovascular balloon occlusion of a giant cervical arteriovenous fistula.

Role of biofilm in cerebrospinal fluid shunt infections: A study at tertiary neurocare center from South India

Directory of Open Access Journals (Sweden)

Kirtilaxmi K Benachinmardi

2017-01-01

Full Text Available Introduction: Biofilms are the source of persistent infections of many pathogenic microbes. They are responsible for nosocomial infection and also associated with many surgical conditions including indwelling medical devices such as ventriculoperitoneal shunt. A significant problem encountered in shunt procedures is obstruction followed by infection, with infection rate ranging from 2% to 27%, often with poor outcome. Materials and Methods: This study was conducted in the Department of Neuromicrobiology at a tertiary neuroinstitute for 6 months from July 1 to December 31, 2014. The samples comprised cerebrospinal fluid (CSF from suspected cases of shunt infections. Laboratory diagnosis of causative agent was established by adopting standard procedures. Then, isolates were evaluated for production of biofilm by tissue culture plate (TCP method and tube method. Results: Of the 1642 shunt CSF samples obtained from neurosurgery, 14.79% were culture positive which yielded 254 isolates. About 51.97% were Gram-negative bacilli (GNB, 46.46% were Gram-positive cocci (GPC, and 1.57% were Candida albicans. Among GNB, nonfermenters were the most common (51.52% followed by Pseudomonas aeruginosa (15.9%. Among GPC, coagulase-negative Staphylococci were 88.13%, out of which 43.26% were methicillin-resistant. Other GPC were Enterococcus spp. (4.24%, Staphylococcus aureus (5.08%, and Streptococcus spp. (2.54%. Among all isolates, 120 were tested for biofilm production, out of which 57.5% were biofilm producers and 42.5% were nonproducers. Conclusions: TCP was the better method to detect biofilm. Most of the biofilm producers were resistant pathogens.

New and improved ways to treat hydrocephalus: Pursuit of a smart shunt

Science.gov (United States)

Lutz, Barry R.; Venkataraman, Pranav; Browd, Samuel R.

2013-01-01

The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a “smart shunt” that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care. PMID:23653889

Predictors of Shunt Dysfunction and Overall Survival in Patients with Variceal Bleeding Treated with Transjugular Portosystemic Shunt Creation Using the Fluency Stent Graft.

Science.gov (United States)

Wan, Yue-Meng; Li, Yu-Hua; Xu, Ying; Wu, Hua-Mei; Li, Ying-Chun; Wu, Xi-Nan; Yang, Jin-Hui

2018-01-16

Transjugular intrahepatic portosystemic shunt (TIPS) is an established method for portal hypertension. This study was to investigate the long-term safety, technical success, and patency of TIPS, and to determine the risk factors and clinical impacts of shunt dysfunction. A total of 154 consecutive patients undergoing embolotherapy of gastric coronary vein and/or short gastric vein and TIPS creation were prospectively studied. Follow-up data included technical success, patency and revision of TIPS, and overall survival of patients. During the study, the primary and secondary technical success rates were 98.7% and 100%, respectively. Sixty-three patients developed shunt dysfunction, 30 with shunt stenosis and 33 with shunt occlusion. The cumulative 60-month primary, primary assisted, and secondary patency rates were 19.6%, 43.0%, and 93.4%, respectively. The cumulative 60-month overall survival rates were similar between the TIPS dysfunction group and the TIPS non-dysfunction group (68.6% vs. 58.6%, P = .096). Baseline portal vein thrombosis (P value of 8.5 had 77.8% sensitivity and 64.8% specificity. The long-term safety, technical success, and patency of TIPS were good; baseline portal vein thrombosis, use of bare stents, and PPG were significantly associated with shunt dysfunction; shunt dysfunction has little impact on patients' long-term survival because of high secondary patency rates. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Traumatic Arteriovenous Fistula of the Scalp in the Left Temporoparietal Region with Intra- and Extracranial Blood Supply

Directory of Open Access Journals (Sweden)

Feng Zheng

2016-01-01

Full Text Available Traumatic AVF of the scalp is a rare abnormal vascular disease. It is defined as a communication between the high flow arterial system and the low flow venous network, which directly connects the arterial feeding vessels of the scalp and the draining veins without an intervening capillary bed. The superficial temporal artery (STA was involved in 90% of the cases, and 71% of the patients only had one dominant feeding STA. Here, we report the case of a rare large traumatic arteriovenous fistula (AVF of the scalp that is fed by intra- and extracranial blood supply. The clinical and radiological features are presented, and the possible pathogenesis and surgical technique are discussed.

Risk factors for shunt malfunction in pediatric hydrocephalus: a multicenter prospective cohort study.

Science.gov (United States)

Riva-Cambrin, Jay; Kestle, John R W; Holubkov, Richard; Butler, Jerry; Kulkarni, Abhaya V; Drake, James; Whitehead, William E; Wellons, John C; Shannon, Chevis N; Tamber, Mandeep S; Limbrick, David D; Rozzelle, Curtis; Browd, Samuel R; Simon, Tamara D

2016-04-01

OBJECT The rate of CSF shunt failure remains unacceptably high. The Hydrocephalus Clinical Research Network (HCRN) conducted a comprehensive prospective observational study of hydrocephalus management, the aim of which was to isolate specific risk factors for shunt failure. METHODS The study followed all first-time shunt insertions in children younger than 19 years at 6 HCRN centers. The HCRN Investigator Committee selected, a priori, 21 variables to be examined, including clinical, radiographic, and shunt design variables. Shunt failure was defined as shunt revision, subsequent endoscopic third ventriculostomy, or shunt infection. Important a priori-defined risk factors as well as those significant in univariate analyses were then tested for independence using multivariate Cox proportional hazard modeling. RESULTS A total of 1036 children underwent initial CSF shunt placement between April 2008 and December 2011. Of these, 344 patients experienced shunt failure, including 265 malfunctions and 79 infections. The mean and median length of follow-up for the entire cohort was 400 days and 264 days, respectively. The Cox model found that age younger than 6 months at first shunt placement (HR 1.6 [95% CI 1.1-2.1]), a cardiac comorbidity (HR 1.4 [95% CI 1.0-2.1]), and endoscopic placement (HR 1.9 [95% CI 1.2-2.9]) were independently associated with reduced shunt survival. The following had no independent associations with shunt survival: etiology, payer, center, valve design, valve programmability, the use of ultrasound or stereotactic guidance, and surgeon experience and volume. CONCLUSIONS This is the largest prospective study reported on children with CSF shunts for hydrocephalus. It confirms that a young age and the use of the endoscope are risk factors for first shunt failure and that valve type has no impact. A new risk factor-an existing cardiac comorbidity-was also associated with shunt failure.

Usefulness of Transjugular Intrahepatic Portosystemic Shunt in the Management of Bleeding Ectopic Varices in Cirrhotic Patients

International Nuclear Information System (INIS)

Vidal, V.; Joly, L.; Perreault, P.; Bouchard, L.; Lafortune, M.; Pomier-Layrargues, G.

2006-01-01

Purpose. To evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in the control of bleeding from ectopic varices. Methods. From 1995 to 2004, 24 cirrhotic patients, bleeding from ectopic varices, mean age 54.5 years (range 15-76 years), were treated by TIPS. The etiology of cirrhosis was alcoholic in 13 patients and nonalcoholic in 11 patients. The location of the varices was duodenal (n = 5), stomal (n = 8), ileocolic (n = 6), anorectal (n = 3), umbilical (n = 1), and peritoneal (n 1). Results. TIPS controlled the bleeding in all patients and induced a decrease in the portacaval gradient from 19.7 ± 5.4 to 6.4 ± 3.1 mmHg. Postoperative complications included self-limited intra-abdominal bleeding (n = 2), self-limited hemobilia (n = 1), acute thrombosis of the shunt (n = 1), and bile leak treated by a covered stent (n = 1). Median follow-up was 592 days (range 28-2482 days). Rebleeding occurred in 6 patients. In 2 cases rebleeding was observed despite a post-TIPS portacaval gradient lower than 12 mmHg and was controlled by variceal embolization; 1 patient underwent surgical portacaval shunt and never rebled; in 3 patients rebleeding was related to TIPS stenosis and treated with shunt dilatation with addition of a new stent. The cumulative rate of rebleeding was 23% and 31% at 1 and 2 years, respectively. One- and 2-year survival rates were 80% and 76%, respectively. Conclusion. The present series demonstrates that bleeding from ectopic varices, a challenging clinical problem, can be managed safely by TIPS placement with low rebleeding and good survival rates

A plasma polymerization technique to overcome cerebrospinal fluid shunt infections

Energy Technology Data Exchange (ETDEWEB)

Coekeliler, D [Plasma Aided Bioengineering and Biotechnology Research Laboratory, Engineering Faculty, Hacettepe University, 06532, Ankara (Turkey); Caner, H [Department of Neurosurgery, School of Medicine, Baskent University, 06610, Ankara (Turkey); Zemek, J [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53, Prague, Czech Republic (Czech Republic); Choukourov, A [Department of Macromolecular Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Biederman, H [Department of Macromolecular Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Mutlu, M [Plasma Aided Bioengineering and Biotechnology Research Laboratory, Engineering Faculty, Hacettepe University, 06532, Ankara (Turkey)

2007-03-01

Prosthetic devices, mainly shunts, are frequently used for temporary or permanent drainage of cerebrospinal fluid. The pathogenesis of shunt infection is a very important problem in modern medicine and generally this is characterized by staphylococcal adhesion to the cerebrospinal fluid shunt surfaces. In this paper, the prevention of the attachment of test microorganism Staphylococcus epidermidis on the cerebrospinal fluid shunt surfaces by 2-hydroxyethylmethacrylate (HEMA) precursor modification in the plasma polymerization system, is reported. Different plasma polymerization conditions (RF discharge power 10-20-30 W, exposure time 5-10-15 min) were employed during the surface modification. The surface chemistry and topology of unmodified and modified shunts was characterized by x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Also, static contact angle measurements were performed to state the change of surface hydrophilicity. All samples were tested in vitro with Staphylococcus epidermidis. A plasma-polymerized HEMA film (PP HEMA) was found to be an alternative simple method to decrease the microorganism attachment and create bacterial anti-fouling surfaces. The attachment of the model microorganism Staphylococcus epidermidis on the shunt surface modified by PP HEMA at 20 W and 15 min was reduced 62.3% if compared to the unmodified control surface of the shunt.

Aberrant hepatic lipid storage and metabolism in canine portosystemic shunts.

Science.gov (United States)

Van den Bossche, Lindsay; Schoonenberg, Vivien A C; Burgener, Iwan A; Penning, Louis C; Schrall, Ingrid M; Kruitwagen, Hedwig S; van Wolferen, Monique E; Grinwis, Guy C M; Kummeling, Anne; Rothuizen, Jan; van Velzen, Jeroen F; Stathonikos, Nikolas; Molenaar, Martijn R; Helms, Bernd J; Brouwers, Jos F H M; Spee, Bart; van Steenbeek, Frank G

2017-01-01

Non-alcoholic fatty liver disease (NAFLD) is a poorly understood multifactorial pandemic disorder. One of the hallmarks of NAFLD, hepatic steatosis, is a common feature in canine congenital portosystemic shunts. The aim of this study was to gain detailed insight into the pathogenesis of steatosis in this large animal model. Hepatic lipid accumulation, gene-expression analysis and HPLC-MS of neutral lipids and phospholipids in extrahepatic (EHPSS) and intrahepatic portosystemic shunts (IHPSS) was compared to healthy control dogs. Liver organoids of diseased dogs and healthy control dogs were incubated with palmitic- and oleic-acid, and lipid accumulation was quantified using LD540. In histological slides of shunt livers, a 12-fold increase of lipid content was detected compared to the control dogs (EHPSS Plipid-related genes to steatosis in portosystemic shunting was corroborated using gene-expression profiling. Lipid analysis demonstrated different triglyceride composition and a shift towards short chain and omega-3 fatty acids in shunt versus healthy dogs, with no difference in lipid species composition between shunt types. All organoids showed a similar increase in triacylglycerols after free fatty acids enrichment. This study demonstrates that steatosis is probably secondary to canine portosystemic shunts. Unravelling the pathogenesis of this hepatic steatosis might contribute to a better understanding of steatosis in NAFLD.

Intrahepatic porto-hepatic venous shunts in Rendu-Osler-Weber disease: imaging demonstration

International Nuclear Information System (INIS)

Matsumoto, Shunro; Mori, Hiromu; Yamada, Yasunari; Hayashida, Tomoko; Hori, Yuzo; Kiyosue, Hiro

2004-01-01

This study describes the imaging features of the intrahepatic portohepatic venous (PHV) shunt, which is a potential cause of portosystemic encephalopathy in Rendu-Osler-Weber disease. Six patients with Rendu-Osler-Weber disease (two men, four women; age range 42-73 years) were retrospectively studied. There were two from one family and three from another family. Of these patients, one was diagnosed with definitive portosystemic encephalopathy because of a psychiatric disorder. We retrospectively reviewed the radiological examinations, including abdominal angiography (n=6), three-phase dynamic helical computed tomography (CT; n=3), and conventional enhanced CT (n=1). In one patient, CT during angiography and CT angioportography were also performed. Evaluation was placed on the imaging features of intrahepatic PHV shunts. On angiography, intrahepatic PHV shunts showing multiple and small shunts <5 mm in diameter in an apparent network were detected in all patents. In two patients, a large shunt with a size of either 7 or 10 mm was associated. These intrahepatic PHV shunts were predominantly distributed in the peripheral parenchyma. Intrahepatic PHV shunts would be characterized by small and multiple shunts in an apparent network on the periphery with or without a large shunt. (orig.)

Embolization with Gamma Knife Radiosurgery of Giant Intracranial Arteriovenous Malformations.

Science.gov (United States)

Chun, Dong Hyun; Kim, Moo Seong; Kim, Sung Tae; Paeng, Sung Hwa; Jeong, Hae Woong; Lee, Won Hee

2016-01-01

Giant arteriovenous malformations (i.e., those greater than 6 cm maximum diameter or volume > 33 cc) are difficult to treat and often carry higher treatment morbidity and mortality rates. In our study, we reviewed the angiographic results and clinical outcomes for 11 patients with giant arteriovenous malformations who were treated between 1994 and 2012. The patients selected included 9 males (82%) and 2 females (18%). Their presenting symptoms were hemorrhage (n=2; 18%), seizure (n=7; 64%), and headache (n=2; 12%). Nine patients were Spetzler-Martin Grade III, 2 were Spetzler-Martin Grade IV. The mean arteriovenous malformation volume was 41 cc (33-52 cc). The mean age of the patients was 45.1 years (24-57 years) and the mean radiation dose delivered to the margin of the nidus was 14.2 Gy. Ten patients received pre-Gamma Knife radiosurgery embolization and Gamma Knife radiosurgery, 1 patient received pre-Gamma Knife radiosurgery embolization and Gamma Knife radiosurgery twice and the interval between Gamma Knife radiosurgeries was 3 months. The complete obliteration rate following Gamma Knife radiosurgery was 36%, subtotal obliteration ( > 70% decreased size of nidus) was 36%, and partial obliteration was 28%. One patient experienced a small hemorrhage after embolization. Combined embolization and Gamma Knife radiosurgery showed successful obliteration of the arteriovenous malformation nidus. The use of embolization to initially reduce nidus size followed by Gamma Knife radiosurgery improves the treatment results. Repeated Gamma Knife radiosurgery should be a treatment option when there is a small nidus remnant.

Calibration of piezoelectric RL shunts with explicit residual mode correction

DEFF Research Database (Denmark)

Høgsberg, Jan Becker; Krenk, Steen

2017-01-01

Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominant vibration modes of a flexible structure and their efficiency relies on the precise calibration of the shunt components. In the present paper improved calibration accuracy is attained by an exte......Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominant vibration modes of a flexible structure and their efficiency relies on the precise calibration of the shunt components. In the present paper improved calibration accuracy is attained...... by an extension of the local piezoelectric transducer displacement by two additional terms, representing the flexibility and inertia contributions from the residual vibration modes not directly addressed by the shunt damping. This results in an augmented dynamic model for the targeted resonant vibration mode...

Fuzzy Inference System Approach for Locating Series, Shunt, and Simultaneous Series-Shunt Faults in Double Circuit Transmission Lines.

Science.gov (United States)

Swetapadma, Aleena; Yadav, Anamika

2015-01-01

Many schemes are reported for shunt fault location estimation, but fault location estimation of series or open conductor faults has not been dealt with so far. The existing numerical relays only detect the open conductor (series) fault and give the indication of the faulty phase(s), but they are unable to locate the series fault. The repair crew needs to patrol the complete line to find the location of series fault. In this paper fuzzy based fault detection/classification and location schemes in time domain are proposed for both series faults, shunt faults, and simultaneous series and shunt faults. The fault simulation studies and fault location algorithm have been developed using Matlab/Simulink. Synchronized phasors of voltage and current signals of both the ends of the line have been used as input to the proposed fuzzy based fault location scheme. Percentage of error in location of series fault is within 1% and shunt fault is 5% for all the tested fault cases. Validation of percentage of error in location estimation is done using Chi square test with both 1% and 5% level of significance.

Endovascular treatment of head and neck arteriovenous malformations

Energy Technology Data Exchange (ETDEWEB)

Dmytriw, A.A. [University Health Network, Joint Department of Medical Imaging, Toronto, Ontario (Canada); Ter Brugge, K.G.; Krings, T.; Agid, R. [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, Ontario (Canada)

2014-03-15

Head and neck arteriovenous malformations (H and N AVM) are associated with considerable clinical and psychosocial burden and present a significant treatment challenge. We evaluated the presentation, response to treatment, and outcome of patients with H and N AVMs treated by endovascular means at our institution. Patients with H and N AVMs treated by endovascular means from 1984 to 2012 were evaluated retrospectively. These included AVMs involving the scalp, orbit, maxillofacial, and upper neck localizations. Patient's clinical files, radiological images, catheter angiograms, and surgical reports were reviewed. Eighty-nine patients with H and N AVMs (46 females, 43 males; 48 small, 41 large) received endovascular therapy. The goals of treatment were curative (n = 30), palliative (n = 34), or presurgical (n = 25). The total number of endovascular treatment sessions was 244 (average of 1.5 per patient). The goal of treatment was met in 92.1 % of cases. Eventual cure was achieved in 42 patients accounting for 58.4 % (52/89) of all patients who underwent treatment for any goal. Twenty-eight of these patients were cured by embolization alone (28/89, 31.4 %) of which 18 were single-hole AVFs. Twenty-four were cured by planned surgical excision after presurgical embolization (24/89, 27 %). Seven patients (7/89, 7.2 %) suffered transient and two (2/89, 2.2 %) permanent endovascular treatment complications. Endovascular treatment is effective for H and N AVMs and relatively safe. It is particularly effective for symptom palliation and presurgical aid. Embolization is curative mostly in small lesions and single-hole fistulas. In patients with large non-curable H and N AVMs, endovascular therapy is often the only palliative option. (orig.)

Prenatal diagnosis of left pulmonary artery-to-pulmonary vein fistula and its successful surgical repair in a neonate.

Science.gov (United States)

Ostras, Oleksii; Kurkevych, Andrii; Bohuta, Lyubomyr; Yalynska, Tetyana; Raad, Tammo; Lewin, Mark; Yemets, Illya

2015-04-01

Pulmonary arteriovenous fistula is a rare disease. To the best of our knowledge, prenatal diagnosis of a fistula between the left pulmonary artery and the left pulmonary vein has not been described in the medical literature. We report a case of the prenatal diagnosis of a left pulmonary artery-to-pulmonary vein fistula, followed by successful neonatal surgical repair.

[Pulmonary arteriovenous fistula with Rendu-Osler-Weber disease].

Science.gov (United States)

Segawa, Masataka; Touge, Masayoshi; Seki, Kouji; Kusajima, Yoshinori; Saito, Katsuhiko

2012-09-01

A 36-year-old man was admitted to our hospital for examination of a nodular shadow in the left lung. Chest 3-dimensional computed tomography (3D-CT) revealed a pulmonary arteriovenous fistula (PAVF) of 21 mm in diameter composed of the feeding artery (A4) and the draining vein (V4) in the left S4. Abdominal enhanced CT revealed multiple hepatic arteriovenous fistula. Brain CT revealed a cavernous hemangioma in right occipital cerebrum. He had a family history, habitual epistaxis, and oral telangiectasia and was diagnosed as Rendu-Osler-Weber disease (hereditary hemorrhagic telangiectasia:HHT). According to his family history, PAVF was likely to be a risk factor of brain infarction and abscess, and the wedge resection of the lingual lobe was performed to remove PAVF.

An unusual case of intrahepatic portosystemic venous shunt

African Journals Online (AJOL)

vena cava (IVC) (most common). Intrahepatic portosystemic venous shunts are rare vascular anomalies that may be detected in asymptomatic patients, given the recent advances in radiological imaging techniques. Accurate shunt evaluation and classification can be performed with ultrasound and multi-detector computed.

Improved distal distribution of n-butyl cyanoacrylate glue by simultaneous injection of dextrose 5% through the guiding catheter: technical note

International Nuclear Information System (INIS)

Moore, Carolyn; Murphy, Kieran; Gailloud, Philippe

2006-01-01

The use of n-butyl cyanoacrylate (NBCA) as an adhesive agent for embolization of high-flow intracranial and extracranial vascular lesions is well established. To be successful, the embolization of arteriovenous malformations and fistulas must achieve obliteration of the arteriovenous shunts themselves rather than simply occlude the feeders proximal to the lesion. However, the feeders cannot always be negotiated over their entire length. This is often the case with dural arteriovenous fistulas (DAVF), which are usually vascularized by long and intricate meningeal networks. In such situations, NBCA may not be able to reach the lesion itself, rendering the embolization ineffective. We present a new technique that improves distal distribution of NBCA glue. The technique described in this report consists of injecting dextrose 5% through the guiding catheter simultaneously with the superselective injection of NBCA glue into the targeted feeding branch. The technique is illustrated with three cases of posterior fossa DAVF. In the reported cases, flooding the territory of the targeted vessel with non-ionic dextrose 5% allowed deep progression of the glue by delaying contact with ionic substances. Excellent distribution of the NBCA glue reaching the site of the arteriovenous shunts was thus obtained despite suboptimal proximal microcatheter tip positions. (orig.)

A comparison of micropore membrane inlet mass spectrometry-derived pulmonary shunt measurement with Riley shunt in a porcine model.

Science.gov (United States)

Duenges, Bastian; Vogt, Andreas; Bodenstein, Marc; Wang, Hemei; Böhme, Stefan; Röhrig, Bernd; Baumgardner, James E; Markstaller, Klaus

2009-12-01

The multiple inert gas elimination technique was developed to measure shunt and the ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung (V(A)'/Q') distributions. Micropore membrane inlet mass spectrometry (MMIMS), instead of gas chromatography, has been introduced for inert gas measurement and shunt determination in a rabbit lung model. However, agreement with a frequently used and accepted method for quantifying deficits in arterial oxygenation has not been established. We compared MMIMS-derived shunt (M-S) as a fraction of total cardiac output (CO) with Riley shunt (R-S) derived from the R-S formula in a porcine lung injury model. To allow a broad variance of atelectasis and therefore shunt fraction, 8 sham animals did not receive lavage, and 8 animals were treated by lung lavages with 30 mL/kg warmed lactated Ringer's solution as follows: 2 animals were lavaged once, 5 animals twice, and 1 animal 3 times. Variables were recorded at baseline and twice after induction of lung injury (T1 and T2). Retention data of sulfur hexafluoride, krypton, desflurane, enflurane, diethyl ether, and acetone were analyzed by MMIMS, and M-S was derived using a known algorithm for the multiple inert gas elimination technique. Standard formulas were used for the calculation of R-S. Forty-four pairs of M-S and R-S were recorded. M-S ranged from 0.1% to 35.4% and R-S from 3.7% to 62.1%. M-S showed a correlation with R-S described by linear regression: M-S = -4.26 + 0.59 x R-S (r(2) = 0.83). M-S was on average lower than R-S (mean = -15.0% CO, sd = 6.5% CO, and median = -15.1), with lower and upper limits of agreement of -28.0% and -2.0%, respectively. The lower and upper limits of the 95% confidence intervals were -17.0 and -13.1 (P < 0.001, Student's t-test). Shunt derived from MMIMS inert gas retention data correlated well with R-S during breathing of oxygen. Shunt as derived by MMIMS was generally less than R-S.

Hybrid management of a spontaneous ilio-iliac arteriovenous fistula: a case report

LENUS (Irish Health Repository)

O'Brien, Gavin C

2011-08-22

Abstract Introduction Spontaneous iliac arteriovenous fistulae are a rare clinical entity. Such localized fistulation is usually a result of penetrating traumatic or iatrogenic injury. Clinical presentation can vary greatly but commonly includes back pain, high-output congestive cardiac failure and the presence of an abdominal bruit. Diagnosis, therefore, is often incidental or delayed. Case presentation We report a case of a spontaneous ilio-iliac arteriovenous fistula in a 68-year-old Caucasian man detected following presentation with unilateral claudication and congestive cardiac failure. Following computed tomography evaluation, the fistula was successfully treated with a combined endovascular (aorto-uni-iliac device) and open (femoro-femoral crossover) approach. Conclusion Endovascular surgery has revolutionized the management of such fistulae and we report an interesting case of a high-output iliac arteriovenous fistulae successfully treated with a hybrid vascular approach.

The dilemma of complicated shunt valves: How to identify patients with posthemorrhagic hydrocephalus after aneurysmatic subarachnoid hemorrhage who will benefit from a simple valve?

Directory of Open Access Journals (Sweden)

Christian von der Brelie

2016-01-01

Full Text Available Background: Sophisticated shunt valves provide the possibility of pressure adjustment and antisiphon control but have a higher probability of valve dysfunction especially in a posthemorrhagic setting. The aim of the present study is to analyze the clinical outcome of patients with shunt dependent posthemorrhagic hydrocephalus after aneurysmatic subarachnoid hemorrhage (SAH in order to identify patients who would benefit from a simple differential pressure valve. Methods: From 2000 to 2013, 547 patients with aneurysmatic SAH were treated at our institution, 114 underwent ventricular shunt placement (21.1%. 47 patients with available pre- and post-operative computed tomography scans, and an available follow-up of minimum 6 months were included. In order to measure the survival time which a nonprogrammable differential pressure valve would have had in an individual patient we defined the initial equalized shunt survival time (IESS. IESS is the time until surgical revisions of fixed differential pressure or flow-regulated valves for the treatment of over- or under-drainage as well as re-programming of adjustable valves due to over- or under-drainage. Results: Twenty patients were treated with fixed differential pressure valves, 15 patients were treated with flow-regulated valves, and 12 underwent ventriculoperitoneal (VP shunt placement with differential pressure valves assisted by a gravitational unit. Patients who reacted with remarkable changes of the ventricular width after the insertion of external ventricular drainage (EVD, before shunt placement, showed a significantly longer IESS. Conclusions: Decline of the ventricular width after EVD placement was a predictor for successful VP shunt therapy in the later course of disease. Possibly, this could allow identifying patients who benefit from a simple differential pressure valve or a flow-regulated valve, and thus could possibly avoid valve-associated complications of a programmable valve in the

Uterine perforation by a cystoperitoneal shunt, an unusual cause of recurrent vaginal discharge.

Science.gov (United States)

Poilblanc, Mathieu; Sentilhes, Loïc; Mercier, Philippe; Lefèbvre, Céline; Descamps, Philippe

2012-01-01

We describe the first reported case of uterine perforation by a cystoperitoneal shunt. The mechanism of this unusual complication is unclear. A 17-year-old patient had a cystoperitoneal shunt for a porencephalic cyst. She presented with recurrent watery vaginal discharge. A pelvic ultrasound examination showed that the uterus had been perforated by the distal tip of the shunt. The cystoperitoneal shunt was converted to a ventriculo-atrial shunt, and the vaginal discharge subsequently resolved. The appearance of light and clear vaginal discharge in a patient with a cystoperitoneal shunt raises the possibility of uterine perforation. This can be confirmed by ultrasound and analysis of the discharge. Removal of the shunt leads to spontaneous closure of the uterine defect.

Aberrant hepatic lipid storage and metabolism in canine portosystemic shunts.

Directory of Open Access Journals (Sweden)

Lindsay Van den Bossche

Full Text Available Non-alcoholic fatty liver disease (NAFLD is a poorly understood multifactorial pandemic disorder. One of the hallmarks of NAFLD, hepatic steatosis, is a common feature in canine congenital portosystemic shunts. The aim of this study was to gain detailed insight into the pathogenesis of steatosis in this large animal model. Hepatic lipid accumulation, gene-expression analysis and HPLC-MS of neutral lipids and phospholipids in extrahepatic (EHPSS and intrahepatic portosystemic shunts (IHPSS was compared to healthy control dogs. Liver organoids of diseased dogs and healthy control dogs were incubated with palmitic- and oleic-acid, and lipid accumulation was quantified using LD540. In histological slides of shunt livers, a 12-fold increase of lipid content was detected compared to the control dogs (EHPSS P<0.01; IHPSS P = 0.042. Involvement of lipid-related genes to steatosis in portosystemic shunting was corroborated using gene-expression profiling. Lipid analysis demonstrated different triglyceride composition and a shift towards short chain and omega-3 fatty acids in shunt versus healthy dogs, with no difference in lipid species composition between shunt types. All organoids showed a similar increase in triacylglycerols after free fatty acids enrichment. This study demonstrates that steatosis is probably secondary to canine portosystemic shunts. Unravelling the pathogenesis of this hepatic steatosis might contribute to a better understanding of steatosis in NAFLD.

[A vertebral arteriovenous fistula diagnosed by auscultation].

Science.gov (United States)

Iglesias Escalera, G; Diaz-Delgado Peñas, R; Carrasco Marina, M Ll; Maraña Perez, A; Ialeggio, D

2015-01-01

Cervical artery fistulas are rare arteriovenous malformations. The etiology of the vertebral arteriovenous fistulas (AVF) can be traumatic or spontaneous. They tend to be asymptomatic or palpation or continuous vibration in the cervical region. An arteriography is necessary for a definitive diagnosis. The treatment is complete embolization of the fistula. We present the case of a two year-old male, where the mother described it «like a washing machine in his head». On palpation during the physical examination, there was a continuous vibration, and a continuous murmur in left cervical region. A vascular malformation in vertebral region was clinically suspected, and confirmed with angio-MRI and arteriography. AVF are rare in childhood. They should be suspected in the presence of noises, palpation or continuous vibration in the cervical region. Early diagnosis can prevent severe complications in asymptomatic children. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Indocyanine green videoangiography "in negative": definition and usefulness in intracranial dural arteriovenous fistulae.

Science.gov (United States)

Simal Julián, Juan Antonio; Miranda Lloret, Pablo; Aparici Robles, Fernando; Beltrán Giner, Andrés; Botella Asunción, Carlos

2013-09-01

Indocyanine green videoangiography (IGV) raises important limitations when we use it in vascular pathology, especially in cases with arterialization of the venous system such as arteriovenous malformations and fistulae. Our objective was to provide a simple procedure that overcomes the limitations of conventional IGV. We define IGV in negative (IGV-IN), so-called because, in its first phase, the vessel to analyze is clipped, and we report 3 cases of intracranial dural arteriovenous fistulae treated with this procedure. In 2011, we applied IGV-IN to 3 patients at our center with Borden type III intracranial arteriovenous fistulae. In all 3 cases, IGV-IN enabled both diagnosis and post-dural arteriovenous fistula exclusion control in 1 integrated procedure no longer than 1 minute, requiring only 1 visualization. IGV-IN is an improvement over the conventional IGV method and is able to provide more information in a shorter period of time. It is an intuitive and highly visual procedure, and, more importantly, it is reversible. Studies with larger samples are necessary to determine whether IGV-IN can further reduce the need for postoperative digital subtraction angiography.

CT in normal pressure hydrocephalus

International Nuclear Information System (INIS)

Fujita, Katsuzo; Nogaki, Hidekazu; Noda, Masaya; Kusunoki, Tadaki; Tamaki, Norihiko

1981-01-01

CT scans were obtained on 33 patients (age 73y. to 31y.) with the diagnosis of normal pressure hydrocephalus. In each case, the diagnosis was made on the basis of the symptoms, CT and cisternographic findings. Underlying diseases of normal pressure hydrocephalus are ruptured aneurysms (21 cases), arteriovenous malformations (2 cases), head trauma (1 case), cerebrovascular accidents (1 case) and idiopathie (8 cases). Sixteen of 33 patients showed marked improvement, five, moderate or minimal improvement, and twelve, no change. The results were compared with CT findings and clinical response to shunting. CT findings were classified into five types, bases on the degree of periventricular hypodensity (P.V.H.), the extent of brain damage by underlying diseases, and the degree of cortical atrophy. In 17 cases of type (I), CT shows the presence of P.V.H. with or without minimal frontal lobe damage and no cortical atrophy. The good surgical improvements were achieved in all cases of type (I) by shunting. In 4 cases of type (II), CT shows the presence of P.V.H. and severe brain damage without cortical atrophy. The fair clinical improvements were achieved in 2 cases (50%) by shunting. In one case of type (III), CT shows the absence of P.V.H. without brain damage nor cortical atrophy. No clinical improvement was obtained by shunting in this type. In 9 cases of type (IV) with mild cortical atrophy, the fair clinical improvement was achieved in two cases (22%) and no improvement in 7 cases. In 2 cases of type (V) with moderate or marked cortical atrophy, no clinical improvement was obtained by shunting. In conclusion, it appeared from the present study that there was a good correlation between the result of shunting and the type of CT, and clinical response to shunting operation might be predicted by classification of CT findings. (author)

The use of abdominal binders to treat over-shunting headaches.

Science.gov (United States)

Sklar, Frederick H; Nagy, Laszlo; Robertson, Brian D

2012-06-01

Headaches are common in children with shunts. Headaches associated with over-shunting are typically intermittent and tend to occur later in the day. Lying down frequently makes the headaches better. This paper examines the efficacy of using abdominal binders to treat over-shunting headaches. Over an 18-year period, the senior author monitored 1027 children with shunts. Office charts of 483 active patients were retrospectively reviewed to identify those children with headaches and, in particular, those children who were thought to have headaches as a result of over-shunting. Abdominal binders were frequently used to treat children with presumed over-shunting headaches, and these data were analyzed. Of the 483 patients undergoing chart review, 258 (53.4%) had headache. A clinical diagnosis of over-shunting was made in 103 patients (21.3% overall; 39.9% of patients with headache). In 14 patients, the headaches were very mild (1-2 on a 5-point scale) and infrequent (1 or 2 per month), and treatment with an abdominal binder was not thought indicated. Eighty-nine patients were treated with a binder, but 19 were excluded from this retrospective study for noncompliance, interruption of the binder trial, or lack of follow-up. The remaining 70 pediatric patients, who were diagnosed with over-shunting headaches and were treated with abdominal binders, were the subjects of a more detailed retrospective study. Significant headache improvement was observed in 85.8% of patients. On average, the patients wore the binders for approximately 1 month, and headache relief usually persisted even after the binders were discontinued. However, the headaches eventually did recur in many of the patients more than a year later. In these patients, reuse of the abdominal binder was successful in relieving headaches in 78.9%. The abdominal binder is an effective, noninvasive therapy to control over-shunting headaches in most children. This treatment should be tried before any surgery is

Surgical management of a patent ductus arteriosus: Is this still an option?

Science.gov (United States)

Weisz, Dany E; Giesinger, Regan E

2018-03-07

The evolution of neonatal intensive care over the past decade has seen the role of surgical patent ductus arteriosus (PDA) ligation in preterm infants both decrease in scope and become laden with uncertainty. Associations of ligation with adverse neonatal and neurodevelopmental outcomes have rendered the ligation decision more challenging for clinicians and have been associated with a decline in surgical treatment, but these findings may be due to bias from confounding by indication in observational studies rather than a causal detrimental effect of ligation. Accordingly, ligation may still be indicated for infants with large ductal shunts and moderate-severe respiratory insufficiency in whom the prospect of timely spontaneous closure appears low. Ultimately a randomized trial of surgical ligation versus conservative management is necessary to assess the efficacy of this invasive intervention in a population of extremely preterm infants with large ductal shunts. Simultaneously, the transcatheter approach to ductal closure in the very immature infant represents an exciting therapeutic alternative but which is still in its infancy. Insights into the pathophysiology of postoperative cardiorespiratory deterioration, including the importance of left ventricular afterload, may help clinicians avoid instability and mitigate a potentially injurious aspect of surgical treatment. This review examines the evidence regarding the benefits and risks of PDA surgery in preterm neonates and provides a pathophysiology-based management paradigm to guide perioperative care in high-risk infants. © 2018 Published by Elsevier Ltd.

Posthemorrhagic Hydrocephalus in Newborns: Clinical Characteristics and Role of Ventriculoperitoneal Shunts

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Inn-Chi Lee

2009-02-01

Conclusion: Patients who were shunt-dependent had worse neurodevelopmental outcomes and greater mortality than those without shunts. The results appeared to depend on how far the hydrocephalus had progressed and on the degree of IVH, but the necessity of VP shunts requires reevaluation before they are implanted.

Comparison between fast contrast-enhanced MR angiography and DSA in diagnosing spinal cord vascular malformations

International Nuclear Information System (INIS)

Wang Wu; Li Minghua; Fang Chun; Wang Jue; Xiao Yunfeng

2007-01-01

Objective: To evaluate the diagnostic and clinical value of fast contrast-enhanced MR angiography (CE-MRA) with elliptic centric phase-encoding in spinal cord vascular malformations. Methods Fast three-dimensional contrast-enhanced MR angiography with elliptic centric phase-encoding and superconducting 1.5T system was applied prospectively in twenty-five consecutive patients with clinically suspected of spinal cord vascular malformations. All cases were performed with selective spinal digital subtraction angiography, including 18 cases treated by surgery and 2 of them with embolization before surgery, MR angiography follow up were undertaken in ten patients after surgery. Comparing fast contrast-enhanced MR angiography with DSA in diagnosing spinal cord vascular malformations included the origin of feeding artery, the feeding artery, the fistula or the nidus, the draining vein, and the vessel image quality based on the gold standard of selective spinal digital subtraction angiography. Results: Surgically proven diseases included spinal arteriovenous malformations(3 cases), spinal cord perimedullary arteriovenous fistulas (5 cases), spinal dural arteriovenous fistulas (8 cases), paravertebral arteriovenous fistulas (1 case), and spontaneous spinal epidural hematomas (2 eases). Comparing with DSA, the accuracy of MR angiography in diagnosing spinal cord vascular malformations; and detecting the origin of the feeding artery, the feeding artery, the shunt or the nidus and the draining vein were 93.8%, 92%, 96.2%, 100% and 100%, respectively. Overall the degree vascular enhencement were judged to be similar(P>0.05), but the vessel continuity of MRA was inferior to DSA (P<0.05). However, 9 cases of MRA showed no abnormal vascular malformation coinciding with those of surgery. Posttreatment MR angiography did not depict any abnormal vessels again. Conclusions: Fast three-dimensional contrast-enhanced MR angiography with elliptic centric phase-encoding may provide

Endovascular management of dural arteriovenous fistulas of the transverse and sigmoid sinus in 150 patients

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Kirsch, M [Ernst-Moritz-Arndt-Universitaet Greifswald, Institut fuer Diagnostische Radiologie und Neuroradiologie, Greifswald (Germany); Liebig, T [TU Muenchen, Institut fuer Neuroradiologie, Klinikum Rechts der Isar, Munich (Germany); Kuehne, D [Klinik fuer Radiologie und Neuroradiologie, Alfried-Krupp-Krankenhaus, Essen (Germany); Henkes, H [Katharinenhospital-Klinikum Stuttgart, Klinik fuer Neuroradiologie, Stuttgart (Germany)

2009-07-15

This study aimed to evaluate the safety and efficiency of the endovascular treatment of transverse-sigmoid sinus dural arteriovenous fistulas (TS{sub d}AVF). A total of 150 consecutive patients and 348 procedures were evaluated. Pulsatile tinnitus (81%), headache (15%), and intracranial hemorrhage (10%) were the most frequent manifestations of the TS{sub d}AVFs. More than half of the affected sinuses were partially or completely thrombosed. Access-wise treatment was performed transarterial (n = 33), transvenous (n = 21), or a combination thereof (n = 96). A mean of 2.4 procedures per patient was required. Immediate postprocedural occlusion rate after transarterial embolization was 30% only. Transvenous treatment alone resulted in an early occlusion rate of 81%, with delayed complete obliteration of half of the remaining fistulas. After combined transarterial/transvenous treatment, the angiographic cure rate was 54%. At follow-up, 88% of patients with residual shunt after the treatment showed complete occlusion. The cumulative complication rate was 9% (n = 13), with minor adverse events in ten patients (7%) and major complications in three patients (2%). Transvenous coil occlusion of the sinus segment with the adjacent dAVF site, eventually combined with transarterial occlusion of supplying arteries, is a very effective and well-tolerated treatment method. In selected patients, variations of these methods (e.g., sinus stenting, compartmental sinus occlusion) can be useful. (orig.)

Endovascular management of dural arteriovenous fistulas of the transverse and sigmoid sinus in 150 patients

International Nuclear Information System (INIS)

Kirsch, M.; Liebig, T.; Kuehne, D.; Henkes, H.

2009-01-01

This study aimed to evaluate the safety and efficiency of the endovascular treatment of transverse-sigmoid sinus dural arteriovenous fistulas (TS d AVF). A total of 150 consecutive patients and 348 procedures were evaluated. Pulsatile tinnitus (81%), headache (15%), and intracranial hemorrhage (10%) were the most frequent manifestations of the TS d AVFs. More than half of the affected sinuses were partially or completely thrombosed. Access-wise treatment was performed transarterial (n = 33), transvenous (n = 21), or a combination thereof (n = 96). A mean of 2.4 procedures per patient was required. Immediate postprocedural occlusion rate after transarterial embolization was 30% only. Transvenous treatment alone resulted in an early occlusion rate of 81%, with delayed complete obliteration of half of the remaining fistulas. After combined transarterial/transvenous treatment, the angiographic cure rate was 54%. At follow-up, 88% of patients with residual shunt after the treatment showed complete occlusion. The cumulative complication rate was 9% (n = 13), with minor adverse events in ten patients (7%) and major complications in three patients (2%). Transvenous coil occlusion of the sinus segment with the adjacent dAVF site, eventually combined with transarterial occlusion of supplying arteries, is a very effective and well-tolerated treatment method. In selected patients, variations of these methods (e.g., sinus stenting, compartmental sinus occlusion) can be useful. (orig.)

Gravitational shunt units may cause under-drainage in bedridden patients.

Science.gov (United States)

Kaestner, S; Kruschat, T; Nitzsche, N; Deinsberger, W

2009-03-01

Implantation of a shunt in a hydrocephalic patient still carries a risk of complications such as over-drainage and under-drainage. Gravitational shunt units are especially designed to minimize the problem of over-drainage. Nevertheless, these valves carry a risk of under-drainage. The best choice of valve for a patient is still challenging. The purpose of this survey was to identify in which patients a gravitational shunt valve is liable to lead to under-drainage. Patients with hydrocephalus entered prospectively into a data base were reviewed retrospectively. The patients were treated between January 2006 to the end of Feb 2007 and those experiencing under- or over-drainage were identified. Thirty-five ventriculo-peritoneal shunt systems were implanted in adult patients. The cause of the hydrocephalus was: normal pressure hydrocephalus in 18 patients, post-haemorrhagic following subarachnoid or intracerebral haemorrhage in 11, associated with a tumour in four and followed a head injury in two patients. Three different valves were used: an adjustable shunt valve with gravitational unit (Pro-GAV 0-20/25 in 21 patients), a gravitational shunt valve with fixed opening pressure (GAV 5/30 in nine patients) and an adjustable differential valve (Hakim medos in five patients). Four patients developed severe, valve-related under-drainage. Each had received a gravitational shunt valve and all were bedridden. In two of these patients it was necessary to change the valve. One patient who had received a differential valve, after regaining mobility developed severe over-drainage with bilateral subdural haematomas. Over-drainage was not seen in long-term bedridden patients with a differential shunt valve. If a bedridden patient with a gravitational shunt valve system lies with a slightly elevated head, this leads to activation of the gravitational unit and this may cause under drainage. As a result, we advise not using an anti-siphon devices in a patient who is bedridden for a

Valved or valveless ventriculoperitoneal shunting in the treatment of post-haemorrhagic hydrocephalus

DEFF Research Database (Denmark)

Andreasen, Trine Hjorslev; Holst, Anders Vedel; Lilja, Alexander

2016-01-01

BACKGROUND: Implant infection and obstruction are major complications for ventriculoperitoneal shunts in patients with post-haemorrhagic hydrocephalus. In an effort to (1) reduce the incidence of these complications, (2) reduce the rate of shunt failure and (3) shorten the duration of neurosurgical...... hospitalisation, we have implemented valveless ventriculoperitoneal shunts at our department for adult patients with post-haemorrhagic hydrocephalus and haemorrhagic cerebrospinal fluid at the time of shunt insertion. METHODS: All adult patients (>18 years old) treated for post-haemorrhagic hydrocephalus.......3 %, p = 0.02), but a higher rate of overdrainage (10.3 % vs 2.6 %, p = 0.04). CONCLUSION: The use of a valveless shunting for patients with post-haemorrhagic hydrocephalus results in shorter duration of neurosurgical hospitalisation and lower rate of shunt infection, although these advantages should...

Percutaneous treatment of thrombosed native arteriovenous dialysis fistula insufficiency: efficacy of mechanical thrombectomy with using the stone basket

International Nuclear Information System (INIS)

Kim, Young Hwan; Ko, Sung Min; Kim, Mi Jung; Kwon, Jung Hyeok; Sohn, Cheol Ho; Choi, Jin Soo; Park, Kyung Sik; Kim, Yong Joo

2006-01-01

We wanted to evaluate the procedural success after percutaneous treatment of thrombosed native arteriovenous dialysis fistula insufficiency and the efficacy of performing mechanical thrombectomy with using the stone basket. From March 2004 to June 2005, 36 thrombosed native hemodialysis access shunts in the upper limbs (brachiocephalic fistulas: 16 and radiocephalic fistulas: 20) were percutaneously treated in 30 patients. Declotting procedures were performed with using urokinase (100,00-200,000 unit) and manual catheter-directed thrombo-aspiration in all the patients. Angioplasty (6 mm in diameter and 4 cm in length) was performed at the identified area of the stenosis and /or with maceration of the thrombus. In 14 cases with massive thrombosis that was refractory to the above mentioned declotting procedures, mechanical thrombectomy with using a Wittich nitinol stone basket (Cook, Bloomington, IN) was performed. Data regarding the procedural success rate and the patency rate were analyzed by means of Fischer's exact test, and the Kaplan-Meier method with the Log-rank test was used for statistical inter-group comparisons between the brachiocephalic and radiocephalic fistulas. Successful declotting and restoration of thrill were achieved in 30 of 36 procedures (83%). Reestablishment of normal dialysis for at least one session was achieved in 29 of 36 procedures (81%). The procedural success rate for the brachiocephalic fistulas was 94% compared with 70% for the radiocephalic fistulas, but the difference was not statistically significant (ρ = 0.104). In the cases with performing mechanical thrombectomy and using the stone basket, procedural success was achieved in 93% (13/14). The expected patency rates at 3, 6 and 12 months were 78%, 61% and 51%, respectively. The patency rates after declotting procedures were not significantly different between the brachiocephalic and radiocephlaic fistulas (ρ = 0.871). Percutaneous treatment of thrombosed native arteriovenous

Percutaneous treatment of thrombosed native arteriovenous dialysis fistula insufficiency: efficacy of mechanical thrombectomy with using the stone basket

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Hwan; Ko, Sung Min; Kim, Mi Jung; Kwon, Jung Hyeok; Sohn, Cheol Ho; Choi, Jin Soo; Park, Kyung Sik [Dongsan Medical Center, Keimyung University College of Medicine, Daegu (Korea, Republic of); Kim, Yong Joo [Andong General Hospital, Andon (Korea, Republic of)

2006-06-15

We wanted to evaluate the procedural success after percutaneous treatment of thrombosed native arteriovenous dialysis fistula insufficiency and the efficacy of performing mechanical thrombectomy with using the stone basket. From March 2004 to June 2005, 36 thrombosed native hemodialysis access shunts in the upper limbs (brachiocephalic fistulas: 16 and radiocephalic fistulas: 20) were percutaneously treated in 30 patients. Declotting procedures were performed with using urokinase (100,00-200,000 unit) and manual catheter-directed thrombo-aspiration in all the patients. Angioplasty (6 mm in diameter and 4 cm in length) was performed at the identified area of the stenosis and /or with maceration of the thrombus. In 14 cases with massive thrombosis that was refractory to the above mentioned declotting procedures, mechanical thrombectomy with using a Wittich nitinol stone basket (Cook, Bloomington, IN) was performed. Data regarding the procedural success rate and the patency rate were analyzed by means of Fischer's exact test, and the Kaplan-Meier method with the Log-rank test was used for statistical inter-group comparisons between the brachiocephalic and radiocephalic fistulas. Successful declotting and restoration of thrill were achieved in 30 of 36 procedures (83%). Reestablishment of normal dialysis for at least one session was achieved in 29 of 36 procedures (81%). The procedural success rate for the brachiocephalic fistulas was 94% compared with 70% for the radiocephalic fistulas, but the difference was not statistically significant ({rho} = 0.104). In the cases with performing mechanical thrombectomy and using the stone basket, procedural success was achieved in 93% (13/14). The expected patency rates at 3, 6 and 12 months were 78%, 61% and 51%, respectively. The patency rates after declotting procedures were not significantly different between the brachiocephalic and radiocephlaic fistulas ({rho} = 0.871). Percutaneous treatment of thrombosed native

Balloon-Occluded Retrograde Transvenous Obliteration of a Gastric Vascular Malformation: An Innovative Approach to Treatment of a Rare Condition

International Nuclear Information System (INIS)

Hansing, Catherine E.; Marquardt, Joseph P.; Sutton, Daniel M.; York, John D.

2017-01-01

Arteriovenous malformations (AVMs) are a high-flow form of a vascular malformation, which can be found anywhere in the body. While historically treated surgically, a multidisciplinary approach utilizing multiple specialties and treatment modalities is now commonly employed. In order to effectively treat an AVM, the nidus must be targeted and eradicated, which can be done via multiple approaches. We present the case of a 43-year-old male with a gastric wall AVM, which was initially incompletely treated using a percutaneous transarterial approach. The gastric AVM was noted to have dominant drainage through a gastrorenal shunt; therefore, Balloon-occluded Retrograde Transvenous Obliteration (BRTO) was utilized to eradicate the AVM nidus. This case illustrates the utility of Interventional Radiology, specifically BRTO, as another treatment option for challenging AVMs.

Balloon-Occluded Retrograde Transvenous Obliteration of a Gastric Vascular Malformation: An Innovative Approach to Treatment of a Rare Condition

Energy Technology Data Exchange (ETDEWEB)

Hansing, Catherine E., E-mail: catherine.e.hansing.mil@mail.mil [Naval Medical Center Portsmouth, Transitional Year/Graduate Medical Education Department, Medical Corps, United States Navy (United States); Marquardt, Joseph P.; Sutton, Daniel M.; York, John D. [Naval Medical Center Portsmouth, Radiology Department, Medical Corps, United States Navy (United States)

2017-02-15

Arteriovenous malformations (AVMs) are a high-flow form of a vascular malformation, which can be found anywhere in the body. While historically treated surgically, a multidisciplinary approach utilizing multiple specialties and treatment modalities is now commonly employed. In order to effectively treat an AVM, the nidus must be targeted and eradicated, which can be done via multiple approaches. We present the case of a 43-year-old male with a gastric wall AVM, which was initially incompletely treated using a percutaneous transarterial approach. The gastric AVM was noted to have dominant drainage through a gastrorenal shunt; therefore, Balloon-occluded Retrograde Transvenous Obliteration (BRTO) was utilized to eradicate the AVM nidus. This case illustrates the utility of Interventional Radiology, specifically BRTO, as another treatment option for challenging AVMs.

Clinical outcomes of temporary shunting for infants with cerebral pseudomeningocele.

Science.gov (United States)

Mattei, Tobias A; Sambhara, Deepak; Bond, Brandon J; Lin, Julian

2014-02-01

Although in the case of subdural collections temporary shunting has been suggested as a viable alternative for definitive drainage of the accumulated fluid until restoration of the normal CSF dynamics, there is no agreement on the best management strategy for pseudomeningocele. The authors performed a retrospective chart review in order to evaluate the clinical outcomes of infants temporarily shunted for pseudomeningocele without encephalocele at our institution (The University of Illinois at Peoria/Illinois Neurological Institute) in the period from 2004 to 2012. The epidemiological characteristics, clinical management, and final outcomes of such subpopulation were compared with a control group which received temporary shunting for subdural hematomas (SDH) during the same period. Four patients (100% male) ranging in age from 8.9 to 27.1 months (mean = 13.88) with pseudomeningocele and 17 patients (64.7% male) ranging in age from 1.9 to 11.8 months (mean = 4.15) with SDH were identified. Although the initial management included sequential percutaneous subdural tapping in 82% of the patients, all children ultimately failed such strategy, requiring either subdural-peritoneal (81% of the cases) or subgaleal-peritoneal (19% of the cases) shunting. The mean implant duration was 201 days for the pseudomeningocele group and 384 days for the SDH one. Mean post-shunt hospitalization was 2 days for patients with pseudomeningocele and 4 days for patients with SDH. There was no statistical difference in terms of complications, length of hospitalization post-shunting, or clinical outcomes between the patients with pseudomeningocele and those with SDH. Temporary shunting of infants with pseudo-meningocele constitutes a viable therapeutic alternative with favorable clinical outcomes and a low risk of shunt dependency similar to those of children with SDH.

Stenotic ligature: a simple technique for managing distal hypoperfusion ischemic syndrome following arteriovenous fistulas

Directory of Open Access Journals (Sweden)

Ene Cristian Roata

2018-05-01

Full Text Available Introduction. Distal Hypoperfusion Ischemic Syndrome (DHIS is a multifactorial debilitating condition causing peripheral ischemia and potentially tissue necrosis. In an effort to further refine its surgical treatment we aim to describe a modified, simple and reliable technique for managing DHIS in patients with arteriovenous fistulas. Materials and Methods. Twenty-nine consecutive patients with DHIS operated by a single surgical team over a period of 7 years were included in the study. All patients underwent the same surgical technique: stenotic ligature. Outcomes were analyzed clinically and the effectiveness of the procedure was proven using McNemar test. Clinical variables were statistically analyzed in SPSS 17.0 for Windows. Results. The technique we used consists in performing a stenosing ligature on the vein, using a 0-silk suture, and adjusting the suture in order to achieve either a radial pulse or capillary pulse, while maintaining a good thrill at palpation of the vein. The procedure was successful in 83% of patients proved by immediate symptomatic relief. Paired data analysis showed significant decrease of all symptoms: cold extremity (p=0,021, paraesthesia (p<0,001, pain (p<0,001. History of coronary artery disease, arteriopathy or the absence of radial pulse is statistically correlated with an increased risk of developing DHIS. Conclusions. Stenotic ligature is a simple, cheap and reliable technique for managing DHIS with lower septic risks which can be easily performed under local anesthesia.

Scoliosis and Syringomyelia With Chiari Malformation After Lumbar Shunting

Directory of Open Access Journals (Sweden)

Hsin-Hung Chen

2010-07-01

Full Text Available Unsteady gait was noted in a 2-year-old boy with a lumboperitoneal (LP shunt that had been inserted 1 year earlier for increased head circumference caused by communicating hydrocephalus. Scoliosis was also noted during postoperative follow-up. Magnetic resonance imaging revealed new hindbrain tonsillar herniation and an extensive syrinx from C3 to L1. The malfunctioning LP shunt was removed and posterior fossa decompression with ventriculoperitoneal shunt insertion was performed. The unsteady gait recovered completely and scoliosis improved. Magnetic resonance imaging demonstrated resolution of the syrinx and tonsillar herniation. Acquired Chiari I malformation after LP shunt is well documented; usually, patients have no symptoms. This is the first report to have all the cause and effect mechanisms among syringomyelia, scoliosis and Chiari I malformation in 1 patient. We review the literature and discuss the possible mechanisms.

Dual pathology causing severe pulmonary hypertension following surgical repair of total anomalous pulmonary venous connection: Successful outcome following serial transcatheter interventions.

Science.gov (United States)

Jain, Shreepal; Bachani, Neeta S; Pinto, Robin J; Dalvi, Bharat V

2018-01-01

Surgical repair of total anomalous pulmonary venous connection (TAPVC) can be complicated by the development of pulmonary venous stenosis later on. In addition, the vertical vein, if left unligated, can remain patent and lead to hemodynamically significant left to right shunting. We report an infant who required transcatheter correction of both these problems after surgical repair of TAPVC.

Cerebral arteriovenous malformation in Noonan's syndrome.

OpenAIRE

Schon, F.; Bowler, J.; Baraitser, M.

1992-01-01

Noonan's syndrome involves the association of multiple congenital abnormalities including neck webbing, pectus excavatum, facial anomalies with a variety of cardiac defects. In this paper the association of Noonan's syndrome with a large cerebral arteriovenous malformation is reported. Congenital cerebrovascular abnormalities are not a recognized feature of the syndrome. The paper also reviews previous reports of neurological associations with Noonan's syndrome, the commonest being mild intel...

Small-Diameter PTFE Portosystemic Shunts: Portocaval vs Mesocaval

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Robert Shields

1998-01-01

Full Text Available Fifty-seven patients with failed sclerotherapy received a mesocaval interposition shunt with an externally supported, ringed polytetrafluoroethylene prosthesis of either 10 or 12 mm diameter. Thirty-one patients had Child-Pugh gradeA disease and 26 grade B; all had a liver volume of 1000– 2500 ml. Follow-up ranged from 16 months to 6 years 3 months. Three patients (5 per cent died in the postoperative period. There were two postoperative recurrences of variceal haemorrhage and one recurrent bleed in the second year after surgery. The cumulative shunt patency rate was 95 per cent and the incidence of encephalopathy 9 per cent; the latter was successfully managed by protein restriction and/or lactulose therapy. The actuarial survival rate for the whole group at 6 years was 78 per cent, for those with Child-Pugh grade A 88 per cent and for grade B 67 per cent. Small-lumen mesocaval interposition shunting achieves portal decompression, preserves hepatopetal flow, has a low incidence of shunt thrombosis, prevents recurrent variceal bleeding and is not associated with significant postoperative encephalopathy.

Shunt impedance of spiral loaded resonant rf cavities

International Nuclear Information System (INIS)

Peebles, P.Z. Jr.; Parvarandeh, M.

1975-01-01

Based upon a treatment of the spiral loaded resonant radio frequency cavity as a shorted quarter-wave transmission line, a model for shunt impedance is developed. The model is applicable to loosely wound spirals in large diameter containers. Theoretical shunt impedance is given for spirals wound from tubing of circular or rectangular cross section. The former produces higher shunt impedance. Measurements made at Oak Ridge National Laboratory on 17 copper cavities are described which support the theoretical results. Theoretical results are also compared to data from twenty-three additional cavities measured at Los Alamos Scientific Laboratory. It is shown that the theoretical function forms a useful means of interpreting the quality of constructed cavities. (author)

Embolization of portal-systemic shunts in cirrhotic patients with chronic recurrent hepatic encephalopathy

International Nuclear Information System (INIS)

Sakurabayashi, Shin; Sezai, Shuichi; Yamamoto, Yoshihiro; Hirano, Masanori; Oka, Hiroshi

1997-01-01

Purpose. To evaluate the efficacy of embolization of portal-systemic shunts in cirrhotic patients with chronic recurrent hepatic encephalopathy (CRHE). Methods. Seven cirrhotic patients with CRHE refractory to medical treatment (3 men and 4 women, mean age 66 years) were studied. Five patients had splenorenal shunts, 1 had a gastrorenal shunt, and 1 had an intrahepatic portal vein-hepatic vein shunt. Shunt embolization was performed using stainless steel coils, with a percutaneous transhepatic portal vein approach in 4 patients and a transrenal vein approach in 3 patients. Results. After embolization, the shunt disappeared in 4 patients on either ultrasound pulsed Doppler monitoring or portography. Complications observed in the 7 patients were fever, transient pleural effusion, ascites, and mild esophageal varices. For 3-6 months after embolization, the 4 patients whose shunts disappeared showed minimal or no reappearance of a shunt, and had no recurrence of encephalopathy. The serum ammonia levels decreased and electroencephalograms also improved. One of the 4 patients, who developed mild esophageal varices, required no treatment. Treatment was effective in 3 of the 4 patients (75%) who underwent embolization via a transhepatic portal vein. Conclusion. Transvascular embolization of shunts improved the outcome in 4 of 7 patients. The most effective embolization was achieved via the percutaneous transhepatic portal vein approach

High-Flow Arterio-Hepatic Venous Shunt in Hepatocellular Carcinoma: Use of Multi-Electrode Radiofrequency for Shunt Obliteration

Energy Technology Data Exchange (ETDEWEB)

Pua, Uei, E-mail: druei@yahoo.com [Tan Tock Seng Hospital, Department of Diagnostic Radiology (Singapore)

2015-10-15

Intra-tumoral arterio-hepatic venous shunting (AHVS) poses an impediment to transarterial chemoembolization of liver tumors. Not only does it present a potential hazard for systemic shunting and embolization, but also the altered flow dynamics may also result in poor delivery of drug/embolics to the target tumor bed. Current available techniques to overcome AVHS include arterial embolization (particles, coils, glue, etc.) or temporary venous occlusion using balloons. We hereby illustrate the use of radiofrequency ablation to obliterate a complex AHVS consisting of a varix-like venous aneurysm.

Notch1 and 4 Signaling Responds to an Increasing Vascular Wall Shear Stress in a Rat Model of Arteriovenous Malformations

Directory of Open Access Journals (Sweden)

Jian Tu

2014-01-01

Full Text Available Notch signaling is suggested to promote the development and maintenance of cerebral arteriovenous malformations (AVMs, and an increasing wall shear stress (WSS contributes to AVM rupture. Little is known about whether WSS impacts Notch signaling, which is important for understanding the angiogenesis of AVMs. WSS was measured in arteriovenous fistulas (AVF surgically created in 96 rats at different time points over a period of 84 days. The expression of Notch receptors 1 and 4 and their ligands, Delta1 and 4, Jagged1, and Notch downstream gene target Hes1 was quantified in “nidus” vessels. The interaction events between Notch receptors and their ligands were quantified using proximity ligation assay. There was a positive correlation between WSS and time (r=0.97; P<0.001. The expression of Notch receptors and their ligands was upregulated following AVF formation. There was a positive correlation between time and the number of interactions between Notch receptors and their ligands aftre AVF formation (r=0.62, P<0.05 and a positive correlation between WSS and the number of interactions between Notch receptors and their ligands (r=0.87, P<0.005. In conclusion, an increasing WSS may contribute to the angiogenesis of AVMs by activation of Notch signaling.

Migration of the peritoneal catheter of a ventriculoperitoneal shunt ...

African Journals Online (AJOL)

Ventricular shunt is a well-established modality in the management of hydrocephalus. However, it can be associated with numerous complications and disastrous consequences. The reported incidence of intra-abdominal complications in infants and children after ventriculoperitoneal (VP) shunt procedures is about 24% ...

Shunted Piezoelectric Vibration Damping Analysis Including Centrifugal Loading Effects

Science.gov (United States)

Min, James B.; Duffy, Kirsten P.; Provenza, Andrew J.

2011-01-01

Excessive vibration of turbomachinery blades causes high cycle fatigue problems which require damping treatments to mitigate vibration levels. One method is the use of piezoelectric materials as passive or active dampers. Based on the technical challenges and requirements learned from previous turbomachinery rotor blades research, an effort has been made to investigate the effectiveness of a shunted piezoelectric for the turbomachinery rotor blades vibration control, specifically for a condition with centrifugal rotation. While ample research has been performed on the use of a piezoelectric material with electric circuits to attempt to control the structural vibration damping, very little study has been done regarding rotational effects. The present study attempts to fill this void. Specifically, the objectives of this study are: (a) to create and analyze finite element models for harmonic forced response vibration analysis coupled with shunted piezoelectric circuits for engine blade operational conditions, (b) to validate the experimental test approaches with numerical results and vice versa, and (c) to establish a numerical modeling capability for vibration control using shunted piezoelectric circuits under rotation. Study has focused on a resonant damping control using shunted piezoelectric patches on plate specimens. Tests and analyses were performed for both non-spinning and spinning conditions. The finite element (FE) shunted piezoelectric circuit damping simulations were performed using the ANSYS Multiphysics code for the resistive and inductive circuit piezoelectric simulations of both conditions. The FE results showed a good correlation with experimental test results. Tests and analyses of shunted piezoelectric damping control, demonstrating with plate specimens, show a great potential to reduce blade vibrations under centrifugal loading.

Derivação ventriculoperitoneal com válvula no tratamento da hidrocefalia infantil Evaluation of the ventriculo-peritoneal shunt with valve in the treatment of hydrocephalus

Directory of Open Access Journals (Sweden)

José Jorge Facure

1972-03-01

Pudenz-Heyer valve. Up to the present time (December, 1970 a total of 54 children are alive with a compensated hydrocephalus and 9 patients died, being impossible to follow-up the 32 remaining cases. The use of the ventriculoperitoneal shunt has eliminated all cardiovascular-pulmonary complications and reduced the number for surgical revisions. Besides, infections involving the draining system are less severe and more easily controlled than those occurring in the ventriculoatrial shunts. After analysis of the surgical techniques as well as complications and results the following conclusions are stated: 1 the use of a valve in the ventriculoperitoneal shunt difficults the oclusion of the peritoneal end of the draining system; 2 good results can be expected without reoperations in about 42,35% of hydrocephalus cases treated by ventriculoperitoneal shunt with valve; 3 ventriculoperitoneal shunts with valve showed better results when compared to ventriculoatrial shunts. This statement is made comparing two groups of hydrocephalic infants submitted to surgery at the same Service and in the same conditions, with the same follow-up period; 4 the cases presented permit to state that at present time the ventriculoperitoneal shunt with valve is the most suitable surgical procedure for hydrocephalus.

Arterio-venous anastomoses in isolated, perfused rat lungs.

Science.gov (United States)

Conhaim, Robert L; Segal, Gilad S; Watson, Kal E

2016-11-01

Several studies have suggested that large-diameter (>25 μm) arterio-venous shunt pathways exist in the lungs of rats, dogs, and humans. We investigated the nature of these pathways by infusing specific-diameter fluorescent latex particles (4, 7, 15, 30, or 50 μm) into isolated, ventilated rat lungs perfused at constant pressure. All lungs received the same mass of latex (5 mg), which resulted in infused particle numbers that ranged from 1.7 × 10 7 4 μm particles to 7.5 × 10 4 50 μm particles. Particles were infused over 2 min. We used a flow cytometer to count particle appearances in venous effluent samples collected every 0.5 min for 12 min from the start of particle infusion. Cumulative percentages of infused particles that appeared in the samples averaged 3.17 ± 2.46% for 4 μm diameter particles, but ranged from 0.01% to 0.17% for larger particles. Appearances of 4 μm particles followed a rapid upslope beginning at 30 sec followed by a more gradual downslope that lasted for up to 12 min. All other particle diameters also began to appear at 30 sec, but followed highly irregular time courses. Infusion of 7 and 15 μm particles caused transient but significant perfusate flow reductions, while infusion of all other diameters caused insignificant reductions in flow. We conclude that small numbers of bypass vessels exist that can accommodate particle diameters of 7-to-50 μm. We further conclude that our 4 μm particle data are consistent with a well-developed network of serial and parallel perfusion pathways at the acinar level. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

What is the risk of infecting a cerebrospinal fluid-diverting shunt with percutaneous tapping?

Science.gov (United States)

Spiegelman, Lindsey; Asija, Richa; Da Silva, Stephanie L; Krieger, Mark D; McComb, J Gordon

2014-10-01

Most CSF-diverting shunt systems have an access port that can be percutaneously tapped. Tapping the shunt can yield valuable information as to its function and whether an infection is present. The fear of causing a shunt infection by tapping may limit the physician's willingness to do so. The authors of this study investigate the risk of infecting a shunt secondary to percutaneous tapping. Following institutional review board approval, CSF specimens obtained from tapping an indwelling CSF-diverting shunt during the 2011 and 2012 calendar years were identified and matched with clinical information. A culture-positive CSF sample was defined as an infection. If results were equivocal, such as a broth-only-positive culture, a repeat CSF specimen was examined. The CSF was obtained by tapping the shunt access port with a 25-gauge butterfly needle after prepping the unshaven skin with chlorhexidine. During the study period, 266 children underwent 542 shunt taps. With 541 taps, no clinical evidence of a subsequent shunt infection was found. One child's CSF went from sterile to infected 11 days later; however, this patient had redness along the shunt tract at the time of the initial sterile tap. The risk of infection from tapping a shunt is remote if the procedure is done correctly.

Numerical and experimental studies of stack shunt current for vanadium redox flow battery

International Nuclear Information System (INIS)

Yin, Cong; Guo, Shaoyun; Fang, Honglin; Liu, Jiayi; Li, Yang; Tang, Hao

2015-01-01

Highlights: • A coupled three-dimensional model of VRB cell stack is developed. • Shunt current of the stack is studied with the model and experiment. • Increased electrolyte resistance in channel and manifold lowers the shunt current. • Shunt current loss increases with stack cell number nonlinearly. - Abstract: The stack shunt current of VRB (vanadium redox flow battery) was investigated with experiments and 3D (three-dimensional) simulations. In the proposed model, cell voltages and electrolyte conductivities were calculated based on electrochemical reaction distributions and SOC (state of charge) values, respectively, while coulombic loss was estimated according to shunt current and vanadium ionic crossover through membrane. Shunt current distributions and coulombic efficiency are analyzed in terms of electrolyte conductivities and stack cell numbers. The distributions of cell voltages and shunt currents calculated with proposed model are validated with single cell and short stack tests. The model can be used to optimize VRB stack manifold and channel designs to improve VRB system efficiency

Hepatic Arterial Perfusion Scintigraphy with '99mTc-Macroaggregated Albumin in Hepatocellular Carcinoma

International Nuclear Information System (INIS)

Kim, Gang Deuk; Sohn, Kwang Joon; Min, Kyung Yoon; Kwon, Young Mi; Kim, Chang Guhn; Noh, Byung Suk; Won, Jong Jin

1994-01-01

Hepatic arterial perfusion scintigraphy with '9 9m Tc macroggregated albumin (HAPS) study was carried out in 16 patients with hepatocellular carcinoma (HCC) and in six patients without liver tumor to evaluate HAPS findings of hepatocellular carcinoma and use fullness of HAPS. HAPS with planar and SPECT study were performed in 22 patients after conventional hepatic or celiac arteriography. For HAPS study, 4 5 mCi of MAA mixed with 2 ml of saline was injected into proper hepatic artery or its distal branches at the rate of approximately 1 ml/sec. We analysed 21 HCCs over 2 cm in diameter(average diameter: 6.4 cm) and 17 of 21 HCCs were over 4 cm in diameter. CT, sonography and angiography were performed within two week in all 16 patients and liver scan was performed in 12 patients. Three different pattern of tumor perfusion were observed in 16 patients with HCC. 1) diffuse increased perfusion in 16 of 21(76%) 2) increased peripheral perfusion in 4 of 21(19%) 3) diffuse decreased perfusion in 1 of 21 (5%) Arteriovenous shunt indicated by lung uptake of MAA were observed in 9 of 16 (56% ). In contrast, angiography demonstrates arteriovenous shunt in 2 of 16 (13%). There was no accumulation of radioactivity on RRC blood pool scan in all six patients with HCC examined. HAPS is useful study in evaluation of perfusion pattern or vascularity of HCC and in detection of arteriovenous shunt.

Prophylactic antibiotics in pediatric shunt surgery.

Science.gov (United States)

Biyani, N; Grisaru-Soen, G; Steinbok, P; Sgouros, S; Constantini, S

2006-11-01

The optimal antibiotic prophylaxis for pediatric shunt-related procedures is not clear. There is much inconsistency among different medical centers. This paper summarizes and analyzes the various prophylactic antibiotic regiments used for shunt-related surgeries at different pediatric neurosurgery centers in the world. A survey questionnaire was distributed through the Pediatric Neurosurgery list-server (an e-mail-based special interest group in pediatric neurosurgery). Forty-five completed questionnaires were received, one per medical center, primarily from pediatric neurosurgeons with the following geographic breakdown: 25 from North America, 13 from Europe, and 7 from Asia and other countries. All centers routinely administered prophylactic antibiotics for shunt-related procedures. The drugs of choice were first-generation cephalosporins (23), second-generation cephalosporins (10), naficillin/oxacillin (4), vancomycin (3), clindamycin (1), amoxicillin (1), and mixed protocols in three centers. The initial drug administration ("first dose") was: in the department before transfer to operating room (5), upon arrival to operating room (11), at induction of anesthesia (13), and at initial skin incision (16). The duration of antibiotic dosage also varied: single dose (13), 24-h administration (26), 48-h administration (2), and longer than 48 h in four centers. Two general tendencies were noted, common to the majority of participating centers. There was a general trend to modify antibiotic treatment protocol in "high-risk" populations. The second common theme noted in more than half of responding centers was the use of long-term antibiotic treatment for externalized devices (such as externalized shunts, external ventricular drains or lumbar drains), usually till the device was in place.

Multi-resonant electromagnetic shunt in base isolation for vibration damping and energy harvesting

Science.gov (United States)

Pei, Yalu; Liu, Yilun; Zuo, Lei

2018-06-01

This paper investigates multi-resonant electromagnetic shunts applied to base isolation for dual-function vibration damping and energy harvesting. Two multi-mode shunt circuit configurations, namely parallel and series, are proposed and optimized based on the H2 criteria. The root-mean-square (RMS) value of the relative displacement between the base and the primary structure is minimized. Practically, this will improve the safety of base-isolated buildings subjected the broad bandwidth ground acceleration. Case studies of a base-isolated building are conducted in both the frequency and time domains to investigate the effectiveness of multi-resonant electromagnetic shunts under recorded earthquake signals. It shows that both multi-mode shunt circuits outperform traditional single mode shunt circuits by suppressing the first and the second vibration modes simultaneously. Moreover, for the same stiffness ratio, the parallel shunt circuit is more effective at harvesting energy and suppressing vibration, and can more robustly handle parameter mistuning than the series shunt circuit. Furthermore, this paper discusses experimental validation of the effectiveness of multi-resonant electromagnetic shunts for vibration damping and energy harvesting on a scaled-down base isolation system.

UTERINE ARTERIOVENOUS MALFORMATION: A CASE REPORT

OpenAIRE

Chandrashekar Murthy; Kiran

2014-01-01

Uterine arteriovenous malformation (AVM) is a rare condition, with less than 100 cases reported in the literature. Despite it being rare, it is a potentially life threatening disease. This case report describes 31- year-old women who presented with abnormal uterine bleeding. Trans abdominal sonography, colour and spectral Doppler imaging was performed, diagnosis was confirmed by non- invasive MRI scan. Laparoscopic bilateral uterine artery ligation was done successfully.

Demonstration of arterioportal shunt by dynamic computed tomography and its diagnostic value

International Nuclear Information System (INIS)

Nakayama, Takatsune; Hiyama, Yoshiaki; Saitoh, Masayuki

1983-01-01

Sixty-one patients, 41 with hepatocellular carcinoma and 20 with liver cirrhosis, were examined by dynamic computed tomography (CT) and all but one with hepatocellular carcinoma were examined by celiac angiography. Dynamic CT disclosed arterioportal shunting in eleven cases of hepatocellular carcinima and in one of cirrhotics. All of them were confirmed by angiography except one case in which angiography could not be performed. In ten of these eleven cases arterioportal shunt was adjacent to a mass lesion on dynamic CT, suggesting tumor invasion into the portal branch. In one with hepatocellular carcinoma, the shunt was remote from the mass. In one with cirrhosis, there was no mass. In these last two cases, the shunt might have been caused by prior percutaneus needle puncture. In another case of hepatocellular carcinoma, celiac angiography but not CT demonstrated an arterioportal shunt. Thus dynamic CT was nearly as diagnostic as celiac arterigraphy for the demonstration of arterioportal shunt due to portal invasion of hepatocellular carcinoma and percutaneus needle puncture. (author)

Demonstration of arterioportal shunt by dynamic computed tomography and its diagnostic value

Energy Technology Data Exchange (ETDEWEB)

Nakayama, Takatsune; Hiyama, Yoshiaki; Saitoh, Masayuki

1983-11-01

Sixty-one patients, 41 with hepatocellular carcinoma and 20 with liver cirrhosis, were examined by dynamic computed tomography (CT) and all but one with hepatocellular carcinoma were examined by celiac angiography. Dynamic CT disclosed arterioportal shunting in eleven cases of hepatocellular carcinoma and in one of cirrhotics. All of them were confirmed by angiography except one case in which angiography could not be performed. In ten of these eleven cases arterooportal shunt was adjacent to a mass lesion on dynamic CT, suggesting tumor invasion into the portal branch. In one with hepatocellular carcinoma, the shunt was remote from the mass. In one with cirrhosis, there was no mass. In these last two cases, the shunt might have been caused by prior percutaneus needle puncture. In another case of hepatocellular carcinoma, celiac angiography but not CT demonstrated an arterioportal shunt. Thus dynamic CT was nearly as diagnostic as celiac arterigraphy for the demonstration of arterioportal shunt due to portal invasion of hepatocellular carcinoma and percutaneus needle puncture.

Dual pathology causing severe pulmonary hypertension following surgical repair of total anomalous pulmonary venous connection: Successful outcome following serial transcatheter interventions

Directory of Open Access Journals (Sweden)

Shreepal Jain

2018-01-01

Full Text Available Surgical repair of total anomalous pulmonary venous connection (TAPVC can be complicated by the development of pulmonary venous stenosis later on. In addition, the vertical vein, if left unligated, can remain patent and lead to hemodynamically significant left to right shunting. We report an infant who required transcatheter correction of both these problems after surgical repair of TAPVC.

Splenophrenic portosystemic shunt in dogs with and without portal ...

African Journals Online (AJOL)

The possible existence of the same pattern of porto-caval connection in dogs having a single congenital portosystemic shunt (CPSS) and in dogs having multiple acquired portosystemic shunt (MAPSS) secondary to portal hypertension (PH) was evaluated. Retrospective evaluation of all CT examinations of patients having ...

Electron microscopic evaluation of a gold glaucoma micro shunt after explantation.

Science.gov (United States)

Berk, Thomas A; Tam, Diamond Y; Werner, Liliana; Mamalis, Nick; Ahmed, Iqbal Ike K

2015-03-01

We present a case of an explanted gold glaucoma micro shunt (GMS Plus) and the subsequent light and electron microscopic analyses. The shunt was implanted in a patient with medically refractive glaucoma. The intraocular pressure (IOP) was stable at 12 mm Hg 6 months postoperatively but spiked to 26 mm Hg 6 months later; membranous growth was visible on the implant gonioscopically. A second gold micro shunt was placed 2 years after the first. The IOP was 7 mm Hg 1 week postoperatively but increased to 23 mm Hg 3 weeks later; similar membranous growth was visible on this implant. One of the shunts was explanted, and light and scanning electron microscopic analyses revealed encapsulation around the shunt exterior and connective tissue invasion of the microstructure. This represents the first electron microscopic analysis of an explanted gold glaucoma micro shunt and the first unequivocal images of the fibrotic pseudo-capsule traversing its microchannels and fenestrations. Dr. Ahmed is a consultant to and has received research grants from Solx, Inc. No other author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Symptomatic spinal cord deformity secondary to a redundant intramedullary shunt catheter

International Nuclear Information System (INIS)

Quencer, R.M.; Montalvo Morse, B.M.; Green, B.A.; Eismont, F.J.

1985-01-01

Right arm pain, motor and sensory loss in the right arm and right facial numbness recurred in a 27 year old quadraplegic shortly after a posttraumatic spinal cord cyst (PTSCC) was shunted via a catheter into the adjacent subarachnoid space. Although shunt malfunction was clinically suspected, metrizamide computed tomography (MCT) suggested that redundancy of the catheter had caused deformity of the spinal cord. This hypothesis was confirmed at surgery when intraoperative spinal sonography (IOSS) showed that the spinal cord deformity at C 1 -C 2 disappeared when the catheter was withdrawn. This case shows that new or recurrent spinal cord symptoms may be due to a mechanical deformity of the cord rather than shunt malfunction, that restricting the length of the shunt catheter which is used to decompress PTSCCs is important, and that IOSS is an indispensible tool for visualizing the changes in spinal cord morphology during shunting procedures. (orig.)

Intrahepatic portal-hepatic venous shunt diagnosed by ultrasonography and computed tomography

International Nuclear Information System (INIS)

Shinagawa, Takashi; Iino, Yasuo; Ukaji, Haruyasu; Ishizuka, Masaharu

1986-01-01

Two cases of intrahepatic portal-hepatic venous shunt found by ultrasonography and computed tomography are reported. The first case came to the hospital because of hematuria. A large shunt between the portal vein and the hepatic vein was demonstrated by ultrasonography done for screening, and confirmed by percutaneous transhepatic portography (PTP). The second case was admitted because of cholelithiasis. Computed tomography with contrast enhancement revealed a dilated portal vein in the upper portion of the right lobe. It was subsequently shown by PTP to be a portal-hepatic venous shunt. Portal vein pressure and histological finding of the liver were normal in both cases. The etiology of the shunt was thought to be congenital in these cases for lack of liver disease, portal hypertension and history of trauma. Both cases had no history of hepatic encephalopathy and did not show any symptom attributable to the shunt. (author)

A new method for the measurement of intrahepatic shunts

International Nuclear Information System (INIS)

Hoefs, J.C.; Reynolds, T.B.; Pare, P.; Sakimura, I.

1984-01-01

After transhepatic portal pressure determination, 96 patients were assessed for the presence of intrahepatic shunts by injection of microspheres (25 +/- 5 micron diameter) into the portal vein using RISA-131I as an indicator of dilution. Multiple portal vein injections in each patient allowed blood sampling from the hepatic vein (site 1) and from two inferior vena cava sampling sites (site 2, at the junction of the hepatic vein orifice with the inferior vena cava, and site 3, 2 to 3 cm closer to or within the right atrium). Intrahepatic shunting was calculated from each site: hepatic vein in 57 patients and inferior vena cava, site 2 in 43 patients and site 3 in 77 patients. At least one valid IHS calculation was available in 92 of the patients. Intrahepatic shunting calculated from sequential portal vein injections with sampling from the hepatic vein was highly correlated (r . 0.98, p less than 0.0001, slope . 1.0), with a mean difference of 1.9% +/- 1.9%. There was no significant difference by t test comparison of the mean IHS calculated from sites 1, 2, and 3. Occasional marked discrepancies were noted between IHS calculated from site 1 or site 2 compared with site 3, and the site 3 calculation was always greater. A shunt index in all patients included shunts calculated from the hepatic vein in 57 patients plus shunt calculation from the inferior vena cava in the remaining patients (site 2 in 26 patients and site 3 in nine). The 82 patients with portal hypertension or chronic liver disease had a higher portal pressure, 13.8 +/- 4.6 mm Hg, and a significantly greater shunt index, 13.7% +/- 24.5% compared with controls. The frequency distribution of IHS in patients with chronic liver disease demonstrated less than 2% IHS in 49% of patients and less than 5% IHS in 63%. The validity of our methods and the implications of the infrequent demonstration of a large IHS are discussed

Determining the optimal portal blood volume in a shunt before surgery in extrahepatic portal hypertension

Directory of Open Access Journals (Sweden)

Yurchuk Vladimir A

2016-04-01

Full Text Available The aim of the study: To determine the necessary shunt diameter and assess the optimal portal blood volume in a shunt in children with extrahepatic portal hypertension before the portosystemic shunt surgery. Changes in the liver hemodynamics were studied in 81 children aged from 4 to 7 years with extrahepatic portal hypertension. We established that it is necessary to calculate the shunt diameter and the blood volume in a shunt in patients with extrahepatic portal hypertension before the portosystemic shunt surgery. It allows us to preserve the hepatic portal blood flow and effectively decrease the pressure in the portal system. Portosystemic shunt surgery in patients with extrahepatic portal hypertension performed in accordance with the individualized shunt volume significantly decreases portal pressure, preserves stable hepatic hemodynamics and prevents gastro-esophageal hemorrhage.

Adding a PECS II block for proximal arm arteriovenous access - a randomised study.

Science.gov (United States)

Quek, K H; Low, E Y; Tan, Y R; Ong, A S C; Tang, T Y; Kam, J W; Kiew, A S C

2018-05-01

Brachial plexus block is often utilised for proximal arm arteriovenous access creation. However, the medial upper arm and axilla are often inadequately anaesthetised, requiring repeated, intraoperative local anaesthetic supplementation, or conversion into general anaesthesia. We hypothesised that the addition of a PECS II block would improve anaesthesia and analgesia for proximal arm arteriovenous access surgery. In this prospective, double-blinded, randomised proof-of-concept study, 36 consenting adults with end-stage renal disease aged between 21 and 90 years received either a combined supraclavicular and PECS II block (Group PECS, n = 18), or combined supraclavicular and sham block (Group SCB, n = 18) for proximal arm arteriovenous access surgery. Primary outcome was whether patients required intraoperative local anaesthetic supplementation by the surgeon. In Group PECS, 33.3% (6/18) needed local anaesthetic supplementation vs. 100% (18/18) in Group SCB. Group SCB had three times (RR 3.0, 95% CI 1.6-5.8; P PECS required lower volume of supplemental local anaesthetic compared to Group SCB (0.0 ml, IQR 0.0-6.3 ml vs. 15.0 ml, IQR 7.4-17.8 ml; P PECS II block to a supraclavicular block improves regional anaesthesia for patients with end-stage renal disease undergoing proximal arm arteriovenous access surgery. © 2018 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Shunt impedance measurement of the APS BBC injector

International Nuclear Information System (INIS)

Sun, Y.E.; Lewellen, J.W.

2006-01-01

The injector test stand (ITS) at Advanced Photon Source (APS) presently incorporates a ballistic bunch compression (BBC) gun, and it is used as a beam source for a number of experiments, including THz generation, beam position monitor testing for the Linac Coherent Light Source (LCLS), novel cathode testing, and radiation therapy source development. The BBC gun uses three independently powered and phased rf cavities, one cathode cell, and two full cells to provide beam energies from 2 to 10 MeV with variable energy spread, energy chirp, and, to an extent, bunch duration. The shunt impedance of an rf accelerator determines how effectively the accelerator can convert supplied rf power to accelerating gradient. The calculation of the shunt impedance can be complicated if the beam energy changes substantially during its transit through a cavity, such as in a cathode cell. We present the results of direct measurements of the shunt impedance of the APS BBC gun on an individual cavity basis, including the cathode cell, and report on achieved gradients. We also present a comparison of the measured shunt impedance with theoretical values calculated from the rf models of the cavities.

Experimental Comparison of Piezoelectric and Magnetostrictive Shunt Dampers

Science.gov (United States)

Asnani, Vivake M.; Deng, Zhangxian; Scheidler, Justin J.; Dapino, Marcelo J.

2016-01-01

A novel mechanism called the vibration ring is being developed to enable energy conversion elements to be incorporated into the driveline of a helicopter or other rotating machines. Unwanted vibration is transduced into electrical energy, which provides a damping effect on the driveline. The generated electrical energy may also be used to power other devices (e.g., health monitoring sensors). PZT (piezoceramic) and PMN-30%PT (single crystal) stacks, as well as a Tb_0.3 Dy_0.7 Fe_1.92 (Terfenol-D) rod with a bias magnet array and a pickup coil, were tested as alternative energy conversion elements to use within the vibration ring. They were tuned for broadband damping using shunt resistors, and dynamic compression testing was conducted in a high-speed load frame. Energy conversion was experimentally optimized at 750Hz by tuning the applied bias stress and resistance values. Dynamic testing was conducted up to 1000Hz to determine the effective compressive modulus, shunt loss factor, internal loss factor, and total loss factor. Some of the trends of modulus and internal loss factor versus frequency were unexplained. The single crystal device exhibited the greatest shunt loss factor whereas the Terfenol-D device had the highest internal and total loss factors. Simulations revealed that internal losses in the Terfenol-D device were elevated by eddy current effects, and an improved magnetic circuit could enhance its shunt damping capabilities. Alternatively, the Terfenol-D device may be simplified to utilize only the eddy current dissipation mechanism (no pickup coil or shunt) to create broadband damping.

Experimental comparison of piezoelectric and magnetostrictive shunt dampers

Science.gov (United States)

Asnani, Vivake M.; Deng, Zhangxian; Scheidler, Justin J.; Dapino, Marcelo J.

2016-04-01

A novel mechanism called the vibration ring is being developed to enable energy conversion elements to be incorporated into the driveline of a helicopter or other rotating machines. Unwanted vibration is transduced into electrical energy, which provides a damping effect on the driveline. The generated electrical energy may also be used to power other devices (e.g., health monitoring sensors). PZT (`piezoceramic') and PMN-30%PT (`single crystal') stacks, as well as a Tb0.3Dy0.7Fe1.92 (`Terfenol-D') rod with a bias magnet array and a pickup coil, were tested as alternative energy conversion elements to use within the vibration ring. They were tuned for broadband damping using shunt resistors, and dynamic compression testing was conducted in a high-speed load frame. Energy conversion was experimentally optimized at 750Hz by tuning the applied bias stress and resistance values. Dynamic testing was conducted up to 1000Hz to determine the effective compressive modulus, shunt loss factor, internal loss factor, and total loss factor. Some of the trends of modulus and internal loss factor versus frequency were unexplained. The single crystal device exhibited the greatest shunt loss factor whereas the Terfenol-D device had the highest internal and total loss factors. Simulations revealed that internal losses in the Terfenol-D device were elevated by eddy current effects, and an improved magnetic circuit could enhance its shunt damping capabilities. Alternatively, the Terfenol-D device may be simplified to utilize only the eddy current dissipation mechanism (no pickup coil or shunt) to create broadband damping.

CT-control of the H-graft interposition mesocaval shunt patency

Energy Technology Data Exchange (ETDEWEB)

Partanen, P L.K.; Oksala, I

1984-02-01

A method for assessing the patency of the H-graft interposition mesocaval shunts by computerized tomography is described. Five patients with such shunts were examined with a 5.5 second CT scanner. After locating the graft a 50 cc bolus of 76% diatrizoate was injected into a cubital vein and 3-4 scans were executed at a preselected level. A distinct vessel like enhancement appeared if the shunt was open. With dynamic CT-scanning the flow can be demonstrated in graphical form as time-density curves.

Congenital pulmonary arteriovenous malformation: a rare cause of ...

African Journals Online (AJOL)

Pulmonary arteriovenous malformation (PAVM) is a rare condition in which there is abnormal connection between pulmonary arteries and veins. The disorder usually appears in late childhood or early adult life, with dyspnea on exertion, clubbing or cyanosis. We present two patients with severe cyanosis and their work-up ...

Intracranial arteriovenous malformation: relationships between clinical and radiographic factors and ipsilateral steal severity

International Nuclear Information System (INIS)

Batjer, H.H.; Devous, M.D. Sr.; Seibert, G.B.; Purdy, P.D.; Ajmani, A.K.; Delarosa, M.; Bonte, F.J.

1988-01-01

Intracranial arteriovenous malformations (AVMs) are high flow shunts that may jeopardize the perfusion of adjacent tissue. Clinical and radiographic data from 62 patients were analyzed to determine their relationship to the severity of steal measured by single photon emission computed tomography (SPECT). The ipsilateral steal index [ISteal(i)] was determined by dividing regional cerebral blood flow (rCBF) values within hand-drawn regions of hypoperfusion in the ipsilateral hemisphere by total brain flow, which was calculated as the average rCBF of each hemisphere. Of the patients, 40% were less than 30 years of age, 45% were 30 to 50 years old, and 15% were over 50. Forty-eight per cent presented with hemorrhage and 34% presented with progressive deficits. There was angiographic steal in 37%, and postoperative hyperemic complications developed in 21%. All patients had ipsilateral regions of hypoperfusion. The ISteal(i) was less than 0.7 in 23 (37%), 0.7 to 0.8 in 20 (32%), and greater than 0.8 in 19 (31%). The ISteal(i) was significantly less severe in the patients over 50; 78% of these patients had an ISteal(i) of greater than 0.8 (P less than 0.01). A history of hemorrhage was associated with less severe steal than that in patients who had not bled (P = 0.088). Patients presenting with a history of progressive deficits had increased severity of steal compared with those without progressive deficits (P less than 0.05). A trend toward decreased severity of steal was noted in patients with unfavorable outcomes

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Medline Plus

Full Text Available ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Contrast Materials Venography Images related to Transjugular Intrahepatic Portosystemic Shunt (TIPS) Sponsored ...

Shunted-Josephson-junction model. II. The nonautonomous case

DEFF Research Database (Denmark)

Belykh, V. N.; Pedersen, Niels Falsig; Sørensen, O. H.

1977-01-01

The shunted-Josephson-junction model with a monochromatic ac current drive is discussed employing the qualitative methods of the theory of nonlinear oscillations. As in the preceding paper dealing with the autonomous junction, the model includes a phase-dependent conductance and a shunt capacitance....... The mathematical discussion makes use of the phase-space representation of the solutions to the differential equation. The behavior of the trajectories in phase space is described for different characteristic regions in parameter space and the associated features of the junction IV curve to be expected are pointed...... out. The main objective is to provide a qualitative understanding of the junction behavior, to clarify which kinds of properties may be derived from the shunted-junction model, and to specify the relative arrangement of the important domains in the parameter-space decomposition....

The transjugular portosystemic stent shunt (TIPSS) as an intervention in clinical complication of portal hypertension; Der transjugulaere portosystemische Stentshunt (TIPSS) als Intervention bei klinischen Komplikationen der portalen Hypertonie

Energy Technology Data Exchange (ETDEWEB)

Thalhammer, A.; Jacobi, V.; Schwarz, W.; Balzer, J.; Abolmaali, N.; Vogl, T.J. [Frankfurt Univ. (Germany). Zentrum der Radiologie

2001-10-01

Most frequent complications in patients with liver cirrhosis are due to portal hypertension. Beside ascites circumvent vessles formate with vasodilatation. Due to counterregulation a secondary hyperaldosteronism develops with release of vasocontrictive agents. If conservative and endoscopic methods fail, indication for building a portosystemic shunt is given. The TIPSS procedure is less invasive than the surgical method of Warren-Shunt, so the radiological intervention has replaced surgery. Reducing the portal pressure by the shunt, the clinical complications change for the better. Still problems are defined as hepatic encephalopathy and right ventricular heart failure. Regular follow up investigations have to be performed to detect complications in the shunt. Using regular clinical and radiological check up TIPSS is of clinical benefit with good long term results. (orig.) [German] Die haeufigsten Komplikationen bei Patienten mit einer Leberzirrhose lassen sich auf das Vorliegen einer portalen Hypertension zurueckfuehren. Neben einer Aszitesbildung kommt es zur Vasodilatation mit Ausbildung portaler Umgehungskreislaeufe, gegenregulatorisch zu einem sekundaeren Hyperaldosteronismus und Ausschuettung vasokonstriktiver Substanzen. Sind mittels konservativer und endoskopischer Methoden die Komplikationen nicht mehr zu beherrschen, ist die Indikation zur Shuntanlage gegeben. Wegen der geringeren Invasivitaet einer TIPSS-Anlage gegenueber der operativen Methode eines Warren-Shunts hat sich die interventionell radiologische Methodik in den letzten Jahren immer mehr durchgesetzt. Durch den mittels Shuntanlage reduzierten Pfortaderdruck kommt es zu einer deutlichen klinischen Besserung der unterschiedlichen Komplikationen. Als klinisch problematische Symptome bei der Shuntanlage sind die hepatische Enzephalopathie und eine Zunahme der Rechtsherzbelastung zu werten. Um Komplikationen im Bereich des Shunts frueh zu erkennen, muss dieser engmaschig kontrolliert werden. Unter

Conversion of Low-Flow Priapism to High-Flow State Using T-Shunt with Tunneling.

Science.gov (United States)

Mistry, Neil A; Tadros, Nicholas N; Hedges, Jason C

2017-01-01

Introduction . The three types of priapism are stuttering, arterial (high-flow, nonischemic), and venoocclusive (low-flow, ischemic). These are usually distinct entities and rarely occur in the same patient. T-shunts and other distal shunts are frequently combined with tunneling, but a seldom recognized potential complication is conversion to a high-flow state. Case Presentation . We describe 2 cases of men who presented with low-flow priapism episodes that were treated using T-shunts with tunneling that resulted with both men having recurrent erections shortly after surgery that were found to be consistent with high-flow states. Case 1 was a 33-year-old male with sickle cell anemia and case 2 was a 24-year-old male with idiopathic thrombocytopenic purpura. In both cases the men were observed over several weeks and both men returned to normal erectile function. Conclusions . Historically, proximal shunts were performed only in cases when distal shunts failed and carry a higher risk of serious complications. T-shunts and other distal shunts combined with tunneling are being used more frequently in place of proximal shunts. These cases illustrate how postoperative erections after T-shunts with tunneling can signify a conversion from low-flow to high-flow states and could potentially be misdiagnosed as an operative failure.

Brain abscesses associated with right-to-left shunts in adults.

Science.gov (United States)

Memon, Kashif A; Cleveland, Kerry O; Gelfand, Michael S

2012-04-01

Although brain abscesses are frequently cryptogenic in origin, bacteria must reach the brain either by direct or hematogenous spread. Right-to-left shunts, caused either by intrapulmonary vascular malformations or congenital heart defects, may allow microorganisms to evade the normal host defenses in the lungs and lead to development of brain abscesses. Two patients recently presented with brain abscesses and were found to have conditions associated with right-to-left shunts. The diagnosis of brain abscess should prompt the clinician to consider right-to-left shunts as a possible predisposing condition for brain abscess.

Embolization of spinal arteriovenous malformations

International Nuclear Information System (INIS)

Son, Mi Young; Kim, Sun Yong; Park, Bok Hwan

1990-01-01

Recently, therapeutic embolization has been advocated as the treatment of choice for spinal AVM(arteriovenous malformations). The authors review our experience with two cases of spinal AVM treated by embolization using coaxial Tracker-18 microcatheter with Latvian. The patients included a 10 year old male with glomus type and a 14 year old female with juvenile type spinal AVM revealed recanalization 5 month later. Embolization provides curative or temporary treatment for spinal AVM. After embolic occlusion, delayed reassessment with arteriography is indicated, particularly if symptoms persist or recur

Balanced calibration of resonant shunt circuits for piezoelectric vibration control

DEFF Research Database (Denmark)

Høgsberg, Jan; Krenk, Steen

2012-01-01

Shunting of piezoelectric transducers and suitable electric circuits constitutes an effective passive approach to resonant vibration damping of structures. Most common design concepts for resonant resistor-inductor (RL) shunt circuits rely on either maximization of the attainable modal damping...

Use of intracranial and ocular thermography before and after arteriovenous malformation excision

Science.gov (United States)

Hwang, Peter Y. K.; Lewis, Philip M.; Maller, Jerome J.

2014-11-01

Excision of arteriovenous malformations (AVMs) is known to carry a risk of postoperative hemorrhage, postulated to be the result of normal perfusion pressure breakthrough. It is also possible that AVMs may cause a steal effect, reducing perfusion in nearby vessels. There is currently no simple method of visualizing the presence or absence of steal effect intraoperatively. We hypothesized that the infrared thermographic (heat sensitive) imaging of perilesional brain may be useful for detecting reduced perfusion due to steal. Moreover, we hypothesized that if steal effect was present, it could impact on ocular perfusion and thereby temperature. Our objective was, therefore, to investigate whether perilesional cortical and ocular temperature (OT) may be a marker of steal effect. We intraoperatively acquired conventional and thermal images of the surgical field and eyes bilaterally, pre- and post-excisions of a large left hemisphere AVM. We found OT asymmetry preoperatively, which was absent after the AVM was excised. Intraoperative thermal images showed an increase of perilesional temperature, although this could be confounded by generalized changes in cortical perfusion due to anesthetics or surgery.

Percutaneous Endoluminal Stent-Graft Repair of an Old Traumatic Femoral Arteriovenous Fistula

International Nuclear Information System (INIS)

Uflacker, Renan; Elliott, Bruce M.

1996-01-01

A stent-graft was custom made to close a high-flow traumatic arteriovenous fistula of the left superficial femoral artery, present for 30 years, in a 60-year-old man with congestive heart failure and ischemic ulceration in the left foot. A balloon expandable Palmaz stent (P394; 2.5 mm x 3.9 cm) was covered with a polytetrafluoroethylene (PTFE) graft and was inserted percutaneously through an 11 Fr vascular sheath. Follow-up Doppler ultrasound at 6 months demonstrated occlusion of the arteriovenous fistula, patency of the artery, and luminal integrity of the artery and vein

Percutaneous gastrostomy tube placement in patients with ventriculoperitoneal shunts

Energy Technology Data Exchange (ETDEWEB)

Sane, S.S.; Towbin, A.; Bergey, E.A.; Kaye, R.D.; Fitz, C.R.; Albright, L.; Towbin, R.B. [Department of Radiology, Children`s Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213 (United States)

1998-07-01

Objective. The purpose of this study is to determine the risk of CNS and/or peritoneal infection in children with ventriculoperitoneal shunts in whom a percutaneous gastrostomy tube is placed. Materials and methods. We placed 205 gastrostomy or gastrojejunostomy tubes from January of 1991 to December 1996. Twenty-three patients (10 boys, 13 girls) had ventriculoperitoneal shunts at the time of placement. All shunts were placed at least 1 month prior to placement of the gastrostomy tube. The patients ranged in age from 8 months to 16 years with a mean age of 6 years, 9 months. Patient weight ranged from 2 kg to 60 kg. All 23 children required long-term nutritional support due to severe neurologic impairment. No prophylactic antibiotics were given prior to the procedure. Of the patients, 21/23 had a 14-F Sacks-Vine gastrostomy tube with a fixed terminal retention device inserted, using percutaneous fluoroscopic antegrade technique. Two of the 23 patients had a Ross 14-F Flexi-flo gastrostomy tube which required a retrograde technique due to a small caliber esophagus in these children. Results. All 23 children had technically successful placements of percutaneous gastrostomy (7) or gastrojejunostomy (16) tubes. Of the children, 21/23 (91 %) had no complications from the procedure. Two of 23 (9 %) patients demonstrated signs of peritonitis after placement of their gastrostomy tubes and subsequently had shunt infections. In both, children CSF culture grew gram-positive cocci. The antegrade technique was used in both children who developed peritonitis. Conclusion. Our study indicates children with ventriculoperitoneal shunts who undergo percutaneous gastrostomy are at greater risk for infection and subsequent shunt malfunction. Therefore, we recommend prophylactic antibiotic therapy to cover for skin and oral flora. (orig.) With 1 fig., 7 refs.

A case report of spinal dural arteriovenous fistula: origins, determinants, and consequences of abnormal vascular malformations.

Science.gov (United States)

Zakhary, Sherry M; Hoehmann, Christopher L; Cuoco, Joshua A; Hitscherich, Kyle; Alam, Hamid; Torres, German

2017-06-01

A spinal dural arteriovenous fistula is an abnormally layered connection between radicular arteries and venous plexus of the spinal cord. This vascular condition is relatively rare with an incidence of 5-10 cases per million in the general population. Diagnosis of spinal dural arteriovenous fistula is differentiated by contrast-enhanced magnetic resonance angiography or structural magnetic resonance imaging, but a definitive diagnosis requires spinal angiography methods. Here, we report a case of a 67-year-old female with a spinal dural arteriovenous fistula, provide a pertinent clinical history to the case nosology, and discuss the biology of adhesive proteins, chemotactic molecules, and transcription factors that modify the behavior of the vasculature to possibly cause sensorimotor deficits.

Development of three-dimensional brain arteriovenous malformation model for patient communication and young neurosurgeon education.

Science.gov (United States)

Dong, Mengqi; Chen, Guangzhong; Qin, Kun; Ding, Xiaowen; Zhou, Dong; Peng, Chao; Zeng, Shaojian; Deng, Xianming

2018-01-15

Rapid prototyping technology is used to fabricate three-dimensional (3D) brain arteriovenous malformation (AVM) models and facilitate presurgical patient communication and medical education for young surgeons. Two intracranial AVM cases were selected for this study. Using 3D CT angiography or 3D rotational angiography images, the brain AVM models were reconstructed on personal computer and the rapid prototyping process was completed using a 3D printer. The size and morphology of the models were compared to brain digital subtraction arteriography of the same patients. 3D brain AVM models were used for preoperative patient communication and young neurosurgeon education. Two brain AVM models were successfully produced. By neurosurgeons' evaluation, the printed models have high fidelity with the actual brain AVM structures of the patients. The patient responded positively toward the brain AVM model specific to himself. Twenty surgical residents from residency programs tested the brain AVM models and provided positive feedback on their usefulness as educational tool and resemblance to real brain AVM structures. Patient-specific 3D printed models of brain AVM can be constructed with high fidelity. 3D printed brain AVM models are proved to be helpful in preoperative patient consultation, surgical planning and resident training.

A rare cause of pediatric urinary incontinence: Ventriculoperitoneal shunt with bladder perforation

Directory of Open Access Journals (Sweden)

Manuel C See IV

2016-04-01

Full Text Available We present a case of 2-year-old boy with long term dysuria and intermittent incontinence, and new onset of fever and headache. Significant past medical history includes congenital hydrocephalus with a ventriculoperitoneal shunt placement two years prior to consult. On physical examination, a tubular structure was noted underneath the prepuce suspected to be the distal tip of ventriculoperitoneal shunt, which was confirmed by kidney, ureter and bladder (KUB X-ray and CT scan. Patient was treated with a novel approach of extraperitoneal removal of ventriculoperitoneal shunt distal tip with cystorrhaphy via a low transverse pfannenstiel incision, separate left ventriculostomy tube insertion and complete removal of ventriculoperitoneal shunt from the right ventricle. This report accounts a rare pediatric case with ventriculoperitoneal shunt perforation into a normal bladder successfully treated with mini-open surgery.

DURAL CAROTID-CAVERNOUS FISTULAS

Directory of Open Access Journals (Sweden)

Barbara Cvenkel

2002-12-01

Full Text Available Background. Dural carotid-cavernous sinus fistulas (CCF are communications fed by meningeal branches of the intracavernous internal carotid artery (ACI or/and external carotid artery (ACE. In contrast to typical CCF, the arteriovenous shunting of blood is usually low flow and low pressure. Spontaneous dural CCF are more common in postmenopausal women. Aetiology is unknown, but congenital malformation or rupture of thin-walled dural arteries within venous sinuses is believed to be the cause.Case reports. 3 cases lacking the typical clinical signs of CCF who had been treated as chronic conjunctivitis, myositis of the extraocular muscle and orbital pseudotumour are presented. Clinical presentation depends on the direction and magnitude of fistular flow and on the anatomy of the collateral branches. If increased blood flow is directed anteriorly in ophthalmic veins the signs of orbito-ocular congestion are present (»redeyed shunt syndrome«. Drainage primarly in the inferior petrosal sinus may cause painful oculomotor and abducens palsies without signs of ocular congestion (»white-eyed shunt syndrome«. Also different therapeutic approaches as well as possible complications are described.Conclusions. For definite diagnosis angiography is obligatory and is also therapeutic as one third to one half of dural CCF close spontaneously. Because of potential severe eye and systemic complications, surgical intervention is indicated only in cases with uncontrolled secondary glaucoma and hypoxic retinopathy.

Gamma Knife radiosurgery for the treatment of intracranial dural arteriovenous fistulas

Science.gov (United States)

Dmytriw, Adam A; Schwartz, Michael L; Cusimano, Michael D; Mendes Pereira, Vitor; Krings, Timo; Tymianski, Michael; Radovanovic, Ivan

2016-01-01

Background Intracranial dural arteriovenous fistulae (DAVF) may present a treatment challenge. Endovascular embolization is in most cases the first line of treatment but does not always achieve cure. Gamma Knife (GK) radiosurgery represents an alternative treatment option, and the purpose of this study was to further evaluate its utility. Methods We reviewed all cases of DAVF treated between 2009 and 2016 at our institution with GK radiosurgery independently, or following failed/refused endovascular or surgical management. Patients’ clinical files, radiological images, catheter angiograms, and surgical DAVF disconnection reports were retrospectively reviewed. Results Sixteen DAVF (14 patients) treated by GK radiosurgery were identified. Eleven fistulae were aggressive and five were benign. Marginal doses ranged from 15 to 25 Gy. Target volumes ranged from 0.04 to 4.47 cm3. In all symptomatic patients, GK treatment resulted in symptom palliation. In 13/15 lesions, cure of symptoms (86.0%) was reported. One lesion was asymptomatic. Angiographic cure was achieved in eight cases (50%), small residual DAVF occurred in four, and four were unchanged. One patient developed headache that resolved at one year. No hemorrhage occurred during the follow-up period. There was no significant association between Borden type and cure rate. Prior failed endovascular treatment and small target volume were associated with lower rates of cure. Conclusions Stereotactic radiosurgery is viable treatment for DAVF. It is very effective in palliating symptoms as a de novo approach or adjunctive to endovascular therapy. In our experience it is only somewhat effective in achieving complete angiographic cure. PMID:28156167

Suicide by severing the arterio-venous subclavian dialysis catheter.

Science.gov (United States)

Edirisinghe, P A S; Busuttil, A

2006-02-01

Haemodialysis access is an essential requirement for haemodialysis treatment in end-stage renal disease. The common forms are arteriovenous fistula (AVF) and arteriovenous grafts in ante-cubital fossa, forearm and upper thigh. Sometimes temporary or immediate access is created via a subclavian catheter or internal jugular catheter. This report is on a 79-year-old man who was suffering from chronic renal failure with a non-functional peripheral AVF; he was being dialysed through a permanent subclavian catheter and he became depressed due to continuing deterioration of his health. He used the easily accessible haemodialysis site as the method of suicide by cutting the tube that connected with the main vessel in his chest and bled to death. This highlights the requirement to assess carefully the patient's mental state in those on chronic haemodialysis, even though very few similar fatal cases have been previously reported.

Prenatal surgery for myelomeningocele and the need for cerebrospinal fluid shunt placement

Science.gov (United States)

Tulipan, Noel; Wellons, John C.; Thom, Elizabeth A.; Gupta, Nalin; Sutton, Leslie N.; Burrows, Pamela K.; Farmer, Diana; Walsh, William; Johnson, Mark P.; Rand, Larry; Tolivaisa, Susan; D’Alton, Mary E.; Adzick, N. Scott

2016-01-01

Object The Management of Myelomeningocele Study (MOMS) was a multicenter randomized trial comparing the safety and efficacy of prenatal and postnatal closure of myelomeningocele. The trial was stopped early because of the demonstrated efficacy of prenatal surgery, and outcomes on 158 of 183 pregnancies were reported. Here, the authors update the 1-year outcomes for the complete trial, analyze the primary and related outcomes, and evaluate whether specific prerandomization risk factors are associated with prenatal surgery benefit. Methods The primary outcome was a composite of fetal loss or any of the following: infant death, CSF shunt placement, or meeting the prespecified criteria for shunt placement. Primary outcome, actual shunt placement, and shunt revision rates for prenatal versus postnatal repair were compared. The shunt criteria were reassessed to determine which were most concordant with practice, and a new composite outcome was created from the primary outcome by replacing the original criteria for CSF shunt placement with the revised criteria. The authors used logistic regression to estimate whether there were interactions between the type of surgery and known prenatal risk factors (lesion level, gestational age, degree of hindbrain herniation, and ventricle size) for shunt placement, and to determine which factors were associated with shunting among those infants who underwent prenatal surgery. Results Ninety-one women were randomized to prenatal surgery and 92 to postnatal repair. The primary outcome occurred in 73% of infants in the prenatal surgery group and in 98% in the postnatal group (p < 0.0001). Actual rates of shunt placement were only 44% and 84% in the 2 groups, respectively (p < 0.0001). The authors revised the most commonly met criterion to require overt clinical signs of increased intracranial pressure, defined as split sutures, bulging fontanelle, or sunsetting eyes, in addition to increasing head circumference or hydrocephalus. Using

Clopidogrel in infants with systemic-to-pulmonary-artery shunts

DEFF Research Database (Denmark)

Wessel, David L; Berger, Felix; Li, Jennifer S

2013-01-01

BACKGROUND: Infants with cyanotic congenital heart disease palliated with placement of a systemic-to-pulmonary-artery shunt are at risk for shunt thrombosis and death. We investigated whether the addition of clopidogrel to conventional therapy reduces mortality from any cause and morbidity relate......-related morbidity. (Funded by Sanofi-Aventis and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00396877.)....

Phenotypic and chemotypic characterization of GABA-shunt mutants in Arabidopsis thaliana

OpenAIRE

Mekonnen, Dereje Worku

2013-01-01

Gamma-Aminobutyric acid (GABA) is a four carbon non protein amino acid, and the pathway that involves its production and degradation is called the GABA shunt. The GABA shunt is a short enzymatic pathway that involves three enzymes: glutamate decarboxylase (GAD), GABA transaminase (GABA-T) and succinic semi aldehyde dehydrogenase (SSADH). GABA shunt is conserved almost in all organisms studied so far. The pathway starts in the cytosol and finishes in mitochondria in higher organisms like plant...

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Medline Plus

Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Transjugular Intrahepatic Portosystemic Shunt ( ...

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles.

Science.gov (United States)

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Diaz Berenstein, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2015-08-01

Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3-9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was pflow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=-0.67--0.70 for all patients on room air, pflow was higher prior to BDG than in other stages. There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. NCT02135081. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Technique to Avoid Hemodialysis Catheter in Patients with Failing Aneurysmal Arteriovenous Fistula by Creating a Concomitant New Arteriovenous Fistula.

Science.gov (United States)

Lara, Kelly A; Chua, Rochelle Anne; Vo, Trung D

2018-05-01

Autogenous arteriovenous fistula (AVF) is the primary recommended access for hemodialysis. Long-term use will not uncommonly result in AVF aneurysmal degeneration. Aneurysm-associated complications encompass pain, skin ulceration, infection, thrombosis, cannulation difficulties, and life-threatening bleeding. Various methods to repair aneurysmal AVFs have been described. However, there may be circumstances when this is not possible and require insertion of a temporary hemodialysis catheter (HDC) until a new arteriovenous access is created. We describe a case series of creating a new simultaneous AVF while continuing to use the primary failing aneurysmal AVF to avoid placement of an HDC. Once the new AVF becomes operational, the primary aneurysmal AVF can be abandoned. Six patients underwent simultaneous new AVF creation, 4 ipsilateral, and 2 contralateral. None of the patients developed symptomatic steal syndrome or congestive heart failure. Five of 6 patients had successful usage of the new AVF, and subsequently underwent ligation and excision of the aneurysmal AVF, thus avoiding a temporary HDC. Close monitoring for skin compromise and bleeding in the aneurysmal AVF is recommended while the new AVF matures. Copyright © 2018 Elsevier Inc. All rights reserved.

Improved severe hepatopulmonary syndrome after liver transplantation in an adolescent with end-stage liver disease secondary to biliary atresia

Directory of Open Access Journals (Sweden)

Tae Jun Park

2014-03-01

Full Text Available Hepatopulmonary syndrome (HPS is a serious complication of end-stage liver disease, which is characterized by hypoxia, intrapulmonary vascular dilatation, and liver cirrhosis. Liver transplantation (LT is the only curative treatment modality for patients with HPS. However, morbidity and mortality after LT, especially in cases of severe HPS, remain high. This case report describes a patient with typical findings of an extracardiac pulmonary arteriovenous shunt on contrast-enhanced transesophageal echocardiography (TEE, and clubbing fingers, who had complete correction of HPS by deceased donor LT. The patient was a 16-year-old female who was born with biliary atresia and underwent porto-enterostomy on the 55th day after birth. She had been suffered from progressive liver failure with dyspnea, clubbing fingers, and cyanosis. Preoperative arterial blood gas analysis revealed severe hypoxia (arterial O2 tension of 54.5 mmHg and O2 saturation of 84.2%. Contrast-enhanced TEE revealed an extracardiac right-to-left shunt, which suggested an intrapulmonary arteriovenous shunt. The patient recovered successfully after LT, not only with respect to physical parameters but also for pychosocial activity, including school performance, during the 30-month follow-up period.

Prevention and treatment of complications after transjugular intrahepatic portosystemic shunt

Directory of Open Access Journals (Sweden)

XUE Hui

2016-02-01

Full Text Available The application of transjugular intrahepatic portosystemic shunt (TIPS in the treatment of cirrhotic portal hypertension has been widely accepted both at home and abroad. This article focuses on the fatal complications of TIPS (including intraperitoneal bleeding and acute pulmonary embolism, shunt failure, and recurrent portosystemic hepatic encephalopathy, and elaborates on the reasons for such conditions and related preventive measures, in order to improve the accuracy and safety of intraoperative puncture, reduce common complications such as shunt failure and hepatic encephalopathy, and improve the clinical effect of TIPS in the treatment of cirrhotic portal hypertension.

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Medline Plus

Full Text Available ... a stent is placed to keep the connection open and allow it to bring blood draining from ... veins within the liver. The shunt is kept open by the placement of a small, tubular metal ...

Intracranial Pressure-Guided Shunt Valve Adjustments with the Miethke Sensor Reservoir.

Science.gov (United States)

Antes, Sebastian; Stadie, Axel; Müller, Simon; Linsler, Stefan; Breuskin, David; Oertel, Joachim

2018-01-01

Telemetric intracranial pressure (ICP) monitoring seems to be a promising therapy-supporting option in shunt-treated patients. Benefits become obvious when headaches are unspecific and clinical symptoms cannot be related to possible overdrainage or underdrainage. In this study, we evaluated a new telemetric device to individually adjust shunt valves according to ICP measurements. Between December 2015 and November 2016, 25 patients with suspected suboptimal shunt valve settings underwent insertion of a telemetric ICP sensor (Sensor Reservoir; Christoph Miethke, Potsdam, Germany). Over a 1-year period, a total of 183 telemetric ICP measurements and 85 shunt valve adjustments were carried out. Retrospective statistic analyses focused on valve adjustments, ICP values, and clinical outcomes. ICP-guided valve adjustments positively changed the clinical state in 18 out of 25 patients. Clinical improvement over time was associated with significant changes of the valve settings and ICP values. Interestingly, a therapeutically normalized ICP profile was not automatically associated with clinical improvement. The Sensor Reservoir is an important and valuable tool for shunt-treated patients suffering from drainage-related problems. The possibility to simultaneously recognize and solve shunt problems represents the decisive advantage. Nevertheless, measurements with the Sensor Reservoir did not allow for the determination of default valve settings or universal target ICP values. Copyright © 2017 Elsevier Inc. All rights reserved.

Stenting of the right ventricular outflow tract after thrombosis of the modified Blalock-Taussig shunt in a 8 month old infant with tetralogy of Fallot and right pulmonary artery agenesis

Directory of Open Access Journals (Sweden)

I. A. Soynov

2017-01-01

Full Text Available Pulmonary artery agenesis combined with tetralogy of Fallot is the most rarely seen congenital heart disease. Children with this anomaly are an especially problematic category of patients undergoing staged surgical repair. The postoperative period quite often is complicated with shunt thrombosis while a redo open surgery is associated with a very high risk; therefore, endovascular repair is a preferred procedure. We describe a case of right ventricular outflow tract stenting in a 8 month old girl with tetralogy of Fallot and right pulmonary artery agenesis. The patient was admitted at 3 month after performing of a left-sided modified Blalock-Taussig shunt with severe signs of heart failure and desaturation caused by shunt thrombosis. Assessments performed at 2 months after stenting of the outflow tract demonstrated good oxygen saturation in arterial blood (80% and above and improvement of heart failure symptoms to NYHA II class.

Clinical and ultrasonographic criteria for using ventriculoperitoneal shunts in newborns with myelomeningocele

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Jose Roberto Tude Melo

2015-09-01

Full Text Available Objective Hydrocephalus is one of the main complications associated with myelomeningocele (MM. This study aimed to identify clinical and ultrasonographic criteria for using ventriculoperitoneal (VP shunts in this group of patients.Method A retrospective cohort study, based on established protocol for VP shunt implant in hydrocephalic children with MM. Parameters used to guide the indication of VP shunts included measurement of head circumference (HC, evaluation of fontanels, and measurement of lateral ventricular atrium (LVA width by transcranial ultrasonography.Results 43 children were included in the analysis, of which 74% had hydrocephalus and required a VP shunt. These children had LVA width ≥ 15 mm, showed increased HC, or had bulging fontanels.Conclusion VP shunt is required in children with increased HC (≥ 2 standard deviation regarding age group, bulging fontanels, or LVA width of ≥ 15 mm after the closure of MM.

Communicating hydrocephalus due to cerebral venous sinus thrombosis treated with ventriculoperitoneal shunt

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Rahul T Chakor

2012-01-01

Full Text Available Cerebral venous sinus thrombosis (CVT is a rare cerebrovascular disease with variable presentation. CVT rarely causes hydrocephalus. Communicating hydrocephalus due to CVT is extremely rare. We describe a patient of CVT presenting with chronic headache and communicating hydrocephalus. The patient was successfully treated with ventriculoperitoneal (VP shunt. A 40 year old man presented with moderate to severe headache since six months and progressive visual loss since two months. Head Computed tomogram showed mild hydrocephalus without obstruction. Lumbar puncture (LP demonstrated elevated pressure but was otherwise normal. Magnetic resonance venogram showed extensive CVT. Repeated CSF drainage and thecoperitoneal shunt did not relieve the severe headache hence a VP shunt was placed. Post shunt headache subsided with resolution of hydrocephalus. CVT can present as communicating hydrocephalus. Gradual reduction of intra-ventricular pressure by repeated LPs followed by VP shunt can safely treat hydrocephalus due to CVT.

Study on the Automatic Detection Method and System of Multifunctional Hydrocephalus Shunt

Science.gov (United States)

Sun, Xuan; Wang, Guangzhen; Dong, Quancheng; Li, Yuzhong

2017-07-01

Aiming to the difficulty of micro pressure detection and the difficulty of micro flow control in the testing process of hydrocephalus shunt, the principle of the shunt performance detection was analyzed.In this study, the author analyzed the principle of several items of shunt performance detection,and used advanced micro pressure sensor and micro flow peristaltic pump to overcome the micro pressure detection and micro flow control technology.At the same time,This study also puted many common experimental projects integrated, and successfully developed the automatic detection system for a shunt performance detection function, to achieve a test with high precision, high efficiency and automation.

Size of gastroesophageal varices: its behavior after the surgical treatment of portal hypertension

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Strauss Edna

1999-01-01

Full Text Available The size of gastroesophageal varices is one of the most important factors leading to hemorrhage related to portal hypertension. An endoscopic evaluation of the size of gastroesophageal varices before and after different operations for portal hypertension was performed in 73 patients with schistosomiasis, as part of a randomized trial: proximal splenorenal shunt (PSS n=24, distal splenorenal shunt (DSS n=24, and esophagogastric devascularization with splenectomy (EGDS n=25. The endoscopic evaluation was performed before and up to 10 years after the operations. Variceal size was graded according to Palmer's classification: grade 1 -- up to 3 mm, grade 2 -- from 3 to 6 mm, grade 3 -- greater than 6 mm, and were analyzed in four anatomical locations: inferior, middle or superior third of the esophagus, and proximal stomach. The total number of points in the pre-operative grading minus the number of points in the post-operative grading gave a differential grading, allowing statistical comparison among the surgical groups. Good results, in terms of disappearance or decrease of variceal size, were observed more frequently after PSS than after DSS or EGDS - 95.8%, 83.3%, and 72%, respectively. When differential grading was analyzed, a statistically significant difference was observed between PSS and EGDS, but not between proximal and distal splenorenal shunts. In conclusion, shunt surgeries were more efficient than devascularization in diminishing variceal size.

Arteriovenous Malformation in Temporal Lobe Presenting as Contralateral Ocular Symptoms Mimicking Carotid-Cavernous Fistula

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Fadzillah Mohd-Tahir

2013-01-01

Full Text Available Aim. To report a rare case of arteriovenous malformation in temporal lobe presenting as contralateral orbital symptoms mimicking carotid-cavernous fistula. Method. Interventional case report. Results. A 31-year-old Malay gentleman presented with 2-month history of painful progressive exophthalmos of his left eye associated with recurrent headache, diplopia, and reduced vision. Ocular examination revealed congestive nonpulsating 7 mm exophthalmos of the left eye with no restriction of movements in all direction. There was diplopia in left lateral gaze. Left IOP was elevated at 29 mmHg. Left eye retinal vessels were slightly dilated and tortuous. CT scan was performed and showed right temporal arteriovenous malformation with a nidus of 3.8 cm × 2.5 cm with right middle cerebral artery as feeding artery. There was dilated left superior ophthalmic vein of 0.9 mm in diameter with enlarged left cavernous sinus. MRA and carotid angiogram confirmed right temporal arteriovenous malformation with no carotid-cavernous fistula. Most of the intracranial drainage was via left cavernous sinus. His signs and symptoms dramatically improved following successful embolisation, completely resolved after one year. Conclusion. Intracranial arteriovenous malformation is rarely presented with primary ocular presentation. Early intervention would salvage the eyes and prevent patients from more disaster morbidity or fatality commonly due to intracranial haemorrhage.

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Medline Plus

Full Text Available ... Intrahepatic Portosystemic Shunt (TIPS)? What are some common uses of the procedure? How should I prepare? What does the equipment look like? How does the procedure work? How is the procedure performed? What will I ...

Endoscopic Third Ventriculostomy Instead of Shunt Revision in Children Younger Than 3 Years of Age.

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Zhao, Rui; Shi, Wei; Yang, Haowei; Li, Hao

2016-04-01

Endoscopic third ventriculostomy (ETV) is a valuable option in the treatment of shunt failure, but no clinical data exist for young children. The aim of this study was to elucidate the role of ETV in patients younger than 3 years of age with shunt malfunction. A cohort of 37 patients younger than 3 years of age with shunt malfunction underwent ETV instead of shunt revision. Patients' preoperative condition and medical history were studied to determine the impact of a number of variables on outcome. The Fisher exact test was used to assess differences among groups. Median age at ETV was 21.6 months (8-36 months). Diagnosis was obstructive hydrocephalus in 24 patients and communicating hydrocephalus in 13. Median age at initial shunt placement was 3.2 months (10 days to 30 months). The etiology of shunt malfunction was obstruction (n = 27) or infection (n = 10). Overall ETV failure rate was 40.5% (15/37). Patients whose age at initial shunt placement was <6 months and/or who had a preterm birth history had higher relative rates of ETV failure. Other variables, including type of hydrocephalus, interval between initial shunt placement and ETV, history of intraventricular bleeding and/or infection, and etiology of shunt malfunction, did not significantly affect the final outcome. Patients younger than 3 years with obstructive or communicating hydrocephalus may benefit from ETV in the event of shunt malfunction and have about a 60% probability of becoming shunt free. Copyright © 2016 Elsevier Inc. All rights reserved.

Percutaneous Transjugular Direct Porto-caval Shunt in Patients with Budd-Chiari Syndrome

International Nuclear Information System (INIS)

Quateen, A.; Pech, M.; Berg, T.; Bergk, A.; Podrabsky, P.; Felix, R.; Ricke, J.

2006-01-01

The purpose of the study was to evaluate the feasibility and effectiveness of direct porto-caval shunts in patients with Budd-Chiari syndrome (BCS) in whom there is no access to the hepatic veins during transjugular intrahepatic portosystemic shunt (TIPSS). We included six consecutive patients with fulminant/acute Budd-Chiari syndrome (mean age: 35 years) in whom a conventional TIPSS was not possible due to inaccessible hepatic veins. We performed a direct porto-caval shunt via a transhepatic approach. Patients were followed up by means of clinical examination, laboratory investigations, and Doppler ultrasound. TIPSS implantation from the inferior vena cava (IVC) was successful in all six patients (100%). The median transhepatic shunt length was 9 cm (8-10 cm). No procedure-related complications were observed in our patients. Early shunt occlusion occurred in three out of six patients (50%). In all three of these patients, the stent used to stabilize the shunt ended 1-2 cm before reaching the IVC. All occlusions were successfully recanalized. One of these patients developed recurrent early shunt as well as mesenteric and splenic vein occlusions. She died 7 days after TIPSS placement due to an unmanageable coagulation disorder. The remaining five patients were followed up by planned clinical examination and laboratory investigations (mean follow-up time was 15 months; patient 1 was followed up for 13 months, patient 2 for 14 months, patient 3 for 15 months, and patients 4 and 5 for 16 months) and all displayed a complete and durable resolution of liver failure and ascites without reintervention. In patients with acute liver failure originating from BCS and inaccessible hepatic veins, a direct transhepatic porto-caval shunt can be performed safely and effectively under ultrasound guidance. Future studies in larger patient groups should investigate if the patency of transcaval TIPSS with long transhepatic shunt segments is similar compared to conventional TIPSS via

A case report of spinal dural arteriovenous fistula: origins, determinants, and consequences of abnormal vascular malformations

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Sherry M. Zakhary, DO

2017-06-01

Full Text Available A spinal dural arteriovenous fistula is an abnormally layered connection between radicular arteries and venous plexus of the spinal cord. This vascular condition is relatively rare with an incidence of 5–10 cases per million in the general population. Diagnosis of spinal dural arteriovenous fistula is differentiated by contrast-enhanced magnetic resonance angiography or structural magnetic resonance imaging, but a definitive diagnosis requires spinal angiography methods. Here, we report a case of a 67-year-old female with a spinal dural arteriovenous fistula, provide a pertinent clinical history to the case nosology, and discuss the biology of adhesive proteins, chemotactic molecules, and transcription factors that modify the behavior of the vasculature to possibly cause sensorimotor deficits.

Spontaneous knot; a rare cause of ventriculoperitoneal shunt blockage.

LENUS (Irish Health Repository)

Mohammed, Wail

2011-02-01

A 14-year old X linked congenital hydrocephalus presented with unexplained headaches and vomiting. He had external ventricular drain and intracranial pressure monitoring (ICP). Subsequently, he underwent exploration and removal of previously inserted ventriculoperitoneal (VP) shunts. On retrieval of peritoneal catheters a double knot was noted between his two distal catheters. This case illustrates a rare cause of ventriculoperitoneal shunt malfunction.

Spontaneous knot; a rare cause of ventriculoperitoneal shunt blockage.

LENUS (Irish Health Repository)

Mohammed, Wail

2012-02-01

A 14-year old X linked congenital hydrocephalus presented with unexplained headaches and vomiting. He had external ventricular drain and intracranial pressure monitoring (ICP). Subsequently, he underwent exploration and removal of previously inserted ventriculoperitoneal (VP) shunts. On retrieval of peritoneal catheters a double knot was noted between his two distal catheters. This case illustrates a rare cause of ventriculoperitoneal shunt malfunction.

Secondary pediatric encephalocele after ventriculosubgaleal shunting for posthemorrhagic hydrocephalus.

Science.gov (United States)

Seeburg, Daniel; Ahn, Edward; Huisman, Thierry

2014-08-01

Intraventricular hemorrhage and posthemorrhagic hydrocephalus continue to be common complications in very low-birth-weight premature infants, often requiring ventricular shunting for cerebrospinal fluid diversion. We report on two infants with posthemorrhagic hydrocephalus that developed a secondary encephalocele after ventriculosubgaleal shunting. Encephaloceles can act as a source of seizure activity and can result in various additional complications including meningitis, abscess formation, and infarction of herniated brain parenchyma. With continued improvements in neonatal intensive care, the survival of infants with significant medical comorbidities-including those that develop posthemorrhagic hydrocephalus requiring ventricular shunting-continues to increase. It is thus important for the radiologist and treating physician to be aware of this rare, potential complication. Georg Thieme Verlag KG Stuttgart · New York.

Midterm Experience of Ipsilateral Axillary-Axillary Arteriovenous Loop Graft as Tertiary Access for Haemodialysis

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J. P. Hunter

2014-01-01

Full Text Available Objectives. To present a series of ipsilateral axillary artery to axillary vein loop arm grafts as an alternative vascular access procedure for haemodialysis in patients with difficult access. Design. Retrospective case series. Methods. Patients who underwent an axillary loop arteriovenous graft from September 2009 to September 2012 were included. Preoperative venous imaging to exclude central venous stenosis and to image arm/axillary veins was performed. A cuffed PTFE graft was anastomosed to the distal axillary artery and axillary vein and looped on the arm. Results. 25 procedures were performed on 22 patients. Median age was 51 years, with 9 males and 13 females. Median number of previous access procedures was 3 (range 0–7. Median followup was 16.4 months (range 1–35. At 3 months and 1 year, the primary and secondary patency rates were 70% and 72% and 36% and 37%, respectively. There were 11 radiological interventions in 6 grafts including 5 angioplasties and 6 thrombectomies. There were 19 surgical procedures in 10 grafts, including thrombectomy, revision, repair for bleeding, and excision. Conclusions. Our series demonstrates that the axillary loop arm graft yields acceptable early patency rates in a complex group of patients but to maintain graft patency required high rates of surgical and radiological intervention, in particular graft thrombectomy.

Impaired arm development after Blalock-Taussig shunts in adults with repaired tetralogy of Fallot.

Science.gov (United States)

Le Gloan, Laurianne; Marcotte, François; Leduc, Hugues; Mercier, Lise-Andrée; Dore, Annie; Mongeon, François-Pierre; Ibrahim, Reda; Miro, Joaquim; Asgar, Anita; Poirier, Nancy; Khairy, Paul

2013-09-30

Many adults with repaired tetralogy of Fallot have had prior Blalock-Taussig shunts. These shunts may theoretically hinder growth and development of the ipsilateral arm. We prospectively enrolled consecutive patients with tetralogy of Fallot in a cross-sectional study to measure arm length and assess handgrip strength. Bilateral handgrip strength was quantified by a dynamometer in a standing position after instructing patients to clench each hand tightly in succession. The maximum force achieved, in kilograms, was measured. A total of 80 consecutive adults with tetralogy of Fallot, aged 36.0 ± 12.5 years, 49% female, were prospectively enrolled. Thirty-eight (47.5%) patients had prior Blalock-Taussig shunts at a median age of 1.0 year. Twenty-one (55.3%) were left-sided and 23 (60.5%) were classic shunts. All but six patients with right-sided shunts and one without a prior shunt were right-handed. The shunts were present for a median of 4.0 years prior to takedown during corrective surgery. The arm ipsilateral to the shunt was significantly shorter than the contralateral arm (71.5 ± 6.1 versus 73.6 ± 5.6 cm, Ptetralogy of Fallot, Blalock-Taussig shunts may impair normal development of the ipsilateral arm with repercussions in adulthood that include shorter limb length and reduced handgrip strength. These changes are most pronounced in patients with classic end-to-side anastomoses. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Radiologist and patient consultation. View full size ... X-Ray and CT Exams Contrast Materials Venography Images related to Transjugular Intrahepatic Portosystemic Shunt (TIPS) Sponsored ...

Animal models of surgically manipulated flow velocities to study shear stress-induced atherosclerosis.

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Winkel, Leah C; Hoogendoorn, Ayla; Xing, Ruoyu; Wentzel, Jolanda J; Van der Heiden, Kim

2015-07-01

Atherosclerosis is a chronic inflammatory disease of the arterial tree that develops at predisposed sites, coinciding with locations that are exposed to low or oscillating shear stress. Manipulating flow velocity, and concomitantly shear stress, has proven adequate to promote endothelial activation and subsequent plaque formation in animals. In this article, we will give an overview of the animal models that have been designed to study the causal relationship between shear stress and atherosclerosis by surgically manipulating blood flow velocity profiles. These surgically manipulated models include arteriovenous fistulas, vascular grafts, arterial ligation, and perivascular devices. We review these models of manipulated blood flow velocity from an engineering and biological perspective, focusing on the shear stress profiles they induce and the vascular pathology that is observed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Low-dose prospectively electrocardiogram-gated axial dual-source CT angiography in patients with pulsatile bilateral bidirectional Glenn Shunt: an alternative noninvasive method for postoperative morphological estimation.

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Xiaopeng Ji

Full Text Available To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG as an alternative noninvasive method for postoperative morphological estimation.Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years underwent both low-dose PGA scanning and conventional cardiac angiography (CCA for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC and pulmonary artery (PA, the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland-Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated.The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P0.The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively.CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG.

Forty years of shunt surgery at Rigshospitalet, Denmark

DEFF Research Database (Denmark)

Mansson, Philip Kofoed; Johansson, Sofia; Ziebell, Morten

2017-01-01

Objective The objective of this study is to review our experience of shunt surgery by investigating 40years of development in terms of rates of revision and infection, shunt survival and risk factors. Design and participants Medical records and operative reports were reviewed retrospectively...... for all patients who underwent primary shunt surgery at our department in the years 2010 to 2012. All results were compared with a previous study from our department. A mixed population consisting of 434 patients was included. Adults (≥15years) accounted for 89.9% of all patients and the mean follow.......1-54.9). Within 4weeks postoperatively, 3.2% had an infection and overall infection rate was 5.5%. Short duration of surgery and the use of antibiotic prophylaxis were associated with a lower risk of infection. The most frequent causes of revision were valve defects (18.4%) and proximal defects or obstructions...

Reduced blood flow through intrapulmonary arteriovenous anastomoses during exercise in lowlanders acclimatizing to high altitude.

Science.gov (United States)

Boulet, Lindsey M; Lovering, Andrew T; Tymko, Michael M; Day, Trevor A; Stembridge, Mike; Nguyen, Trang Anh; Ainslie, Philip N; Foster, Glen E

2017-06-01

What is the central question of this study? The aim was to determine, using the technique of agitated saline contrast echocardiography, whether exercise after 4-7 days at 5050 m would affect blood flow through intrapulmonary arteriovenous anastomoses (Q̇IPAVA) compared with exercise at sea level. What is the main finding and its importance? Despite a significant increase in both cardiac output and pulmonary pressure during exercise at high altitude, there is very little Q̇IPAVA at rest or during exercise after 4-7 days of acclimatization. Mathematical modelling suggests that bubble instability at high altitude is an unlikely explanation for the reduced Q̇IPAVA. Blood flow through intrapulmonary arteriovenous anastomoses (Q̇IPAVA) is elevated during exercise at sea level (SL) and at rest in acute normobaric hypoxia. After high altitude (HA) acclimatization, resting Q̇IPAVA is similar to that at SL, but it is unknown whether this is true during exercise at HA. We reasoned that exercise at HA (5050 m) would exacerbate Q̇IPAVA as a result of heightened pulmonary arterial pressure. Using a supine cycle ergometer, seven healthy adults free from intracardiac shunts underwent an incremental exercise test at SL [25, 50 and 75% of SL peak oxygen consumption (V̇O2 peak )] and at HA (25 and 50% of SL V̇O2 peak ). Echocardiography was used to determine cardiac output (Q̇) and pulmonary artery systolic pressure (PASP), and agitated saline contrast was used to determine Q̇IPAVA (bubble score; 0-5). The principal findings were as follows: (i) Q̇ was similar at SL rest (3.9 ± 0.47 l min -1 ) compared with HA rest (4.5 ± 0.49 l min -1 ; P = 0.382), but increased from rest during both SL and HA exercise (P exercise (P = 0.003); (iii) Q̇IPAVA was increased from SL rest (0) to HA rest (median = 1; P = 0.04) and increased from resting values during SL exercise (P exercise (P = 0.91), despite significant increases in Q̇ and PASP. Theoretical

Shunt hybrid active power filter for harmonic mitigation: A practical ...

Indian Academy of Sciences (India)

The increasing importance of Power Quality problems has been responsible for several improvements in Active Power Filter (APF) typologies in the last decade. The increased cost and switching losses make a pure shunt APF economically impractical for high power applications. In higher power levels shunt Hybrid Active ...

Is a Swine Model of Arteriovenous Malformation Suitable for Human Extracranial Arteriovenous Malformation? A Preliminary Study

Energy Technology Data Exchange (ETDEWEB)

Lv, Ming-ming, E-mail: lvmingming001@163.com [Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Department of Oral and Maxillofacial Surgery, Shanghai Key Laboratory of Stomatology (China); Fan, Xin-dong, E-mail: fanxindong@yahoo.com.cn [Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Department of Radiology (China); Su, Li-xin, E-mail: sulixin1975@126.com [Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Department of Oral and Maxillofacial Surgery, Shanghai Key Laboratory of Stomatology (China)

2013-10-15

Objective: A chronic arteriovenous malformation (AVM) model using the swine retia mirabilia (RMB) was developed and compared with the human extracranial AVM (EAVM) both in hemodynamics and pathology, to see if this brain AVM model can be used as an EAVM model. Methods: We created an arteriovenous fistula between the common carotid artery and the external jugular vein in eight animals by using end-to-end anastomosis. All animals were sacrificed 1 month after surgery, and the bilateral retia were obtained at autopsy and performed hematoxylin and eosin staining and immunohistochemistry. Pre- and postsurgical hemodynamic evaluations also were conducted. Then, the blood flow and histological changes of the animal model were compared with human EAVM. Results: The angiography after operation showed that the blood flow, like human EAVM, flowed from the feeding artery, via the nidus, drained to the draining vein. Microscopic examination showed dilated lumina and disrupted internal elastic lamina in both RMB of model and nidus of human EAVM, but the thickness of vessel wall had significant difference. Immunohistochemical reactivity for smooth muscle actin, angiopoietin 1, and angiopoietin 2 were similar in chronic model nidus microvessels and human EAVM, whereas vascular endothelial growth factor was significant difference between human EAVM and RMB of model. Conclusions: The AVM model described here is similar to human EAVM in hemodynamics and immunohistochemical features, but there are still some differences in anatomy and pathogenetic mechanism. Further study is needed to evaluate the applicability and efficacy of this model.

Is a Swine Model of Arteriovenous Malformation Suitable for Human Extracranial Arteriovenous Malformation? A Preliminary Study

International Nuclear Information System (INIS)