Systematic Occlusion of Shunts (original) (raw)
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An Improved Porto-systemic Shunt Technique in Rodents
The mechanisms involved in the development of hepatic encephalopathy still remain uncertain. The rodent portacaval shunt is a model that reproduces many of the pathological features observed in humans (1), but is a technically demanding exercise. While the traditional technique involves complete occlusion of the IVC, a c-clamp was fashioned to partially clamp the IVC thereby sustaining venous return and cardiac output. The aim of this study is to determine if the c-clamp technique provides greater hemodynamic stability and enhances the success rate of the portacaval shunt procedure. To answer this question, two experimental groups, c-clamp (N = 7) and cross-clamp (N = 7), and a sham group (N = 3) were included. Intraoperative hemodynamic parameters were recorded at specific times during the procedure. The c-clamp group showed greater hemodynamic stability when compared to the cross-clamp group. It was manifested by 1) significantly higher mean arterial blood pressure [63 (range, 8) vs 47 (range, 10) mmHg, p < 0.05], 2) faster capillary refill [4 (range, 2) vs 6 (range, 2) seconds, p < 0.05], 3) higher urinary output [0.18 (range, 0.02) vs 0.14 (range, 0.02) ml, p < 0.05], and 4) lower bowel wet-to-dry ratio [4.168 (range, 0.258) vs 4.731 (range, 0.271), p < 0.05]. We conclude partial IVC clamping improves hemodynamic stability during the construction of the rat portacaval shunt model.
The contribution of SPECT/CT in patients with radionuclide shuntography through shunt dysfunction
Clinical Neurology and Neurosurgery, 2020
Radionuclide CSF study is a simple, effective, and low-radiation-dose procedure for the assessment of shunt patency. With the help of CT image of single-photon emission computed tomography/computed tomography (SPECT/CT), the interpretation becomes more accurate and easier.The aim of this study was to compare the classical methods and 2D planar scintigraphic images with radionuclide shuntography fused SPECT/CT. Methods: Between 2015-2019 all hydrocephalic patients who underwent radionuclide shuntography and classical methods (cranial CT, USG and/or direct X-rays), for suspected VP shunt malfunction at our hospital were retrospectively enrolled in the study. Fusion with SPECT/CT is provided in all radionuclide shuntographies. Approximately 0.5-1 mCi diethylene-triaminepentaaceticacid (DTPA) was intrathecally injected. Images were collected as 5-second frames for the first minute, and 1-min frames for the second to the 30th min. Static whole body images were obtained as early (30 min) and delayed (120 min) images. SPECT/CT was performed in 120 min. Results: When the classical methods were evaluated in the operated patients, according to the direct radiographic findings, in only 17 patients had shunt dysfunction due to disconnection-kinking or laceration, was obtained.On the other hand,while67 shuntography were evaluated,65 of these patients (97%) whose intraoperative and shuntography findings were found to be compatible with each other. Conclusion: The 3D SPECT images combined with the two-dimensional planar images added to the CT provide more accurate information and also provide detailed anatomical information. The patient's operation was performed successfully in one session in cooperation with the other surgical branches when needed.
Australian and New Zealand Journal of Surgery, 2008
The long term morbidity and mortality of two consecutive groups of patients undergoing successful shunt surgery for bleeding oesophageal varices has been studied. Twenty-seven patients with a non-selective shunt in the form of a mesocaval Dacron 'H' graft and 21 patients with selective variceal decompression via a distal lienorenal shunt, all of whom had a patent shunt on discharge from hospital, were included in the study. Shunt associated encephalopathy was documented in 77% of the patients following mesocaval shunts and only 19% of patients following distal lienorenal surgery. Other postoperative morbidity was largely related to problems with the synthetic Dacron graft. Late shunt blockage, often resulting in recurrent variceal bleeding, was documented in 25% of these patients and shunt infection was responsible for complicating fatal disseminated sepsis in 18.5%.
Obstruction in Modified Blalock Shunts: A Quantitative Analysis With Clinical Correlation
The Annals of Thoracic Surgery, 2005
Background. Despite numerous reports describing the clinical course of patients undergoing a modified Blalock-Taussig shunt (MBTS), there is limited information on shunt obstruction. No studies have quantified MBTS stenosis histopathologically and correlated that with demographic and clinical risk factors. Methods. From June 2001 to June 2003, 155 patients had MBTS takedown. The shunt operation (at median age 6 days; shunt size 3.5 mm in 56 [36%]; 4 mm in 84 [54%]; 5 mm in 15 [10%]) was performed on cardiopulmonary bypass (CPB) in 96 patients (62%). At elective takedown (at median 8.1 months), the shunt was excised and histopathologically analyzed for maximal narrowing. Demographics and clinical variables including age, weight, shunt size and duration, diagnosis, use of cardiopulmonary bypass, blood products, anastomosis sites, and concomitant antegrade flow were then tested for correlation with shunt stenosis.
VP Shunt Complications: Ten Years Experience at UDMNINAS
Nepal Journal of Neuroscience
Ventriculo-Peritoneal shunt is significantly associated with complications like malfunction and infection. In this study, we aim to review our infection and malfunction rate. This is a retrospective review of charts of patients who underwent ventriculo-peritonealshunt at Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Bansbari, Nepal between 2008 and 2018. Patients were interviewed via telephone for information regarding shunt complications in the form of malfunction, infection, and the need for revision. A total of 357 patients underwent ventriculoperitonealshunt over a period of 10 years. of patients was 37.08 years. There were224 males and133 females with M:F::1.7:1.265 patients were available over telephone for interview. 54 of 265 (20.37%) patients needed shunt revision. 32 (12.07%) of them had shunt malfunction. 21 (7.92%) of them had shunt infection. One (0.37%) patient had problems with over drainage. Shunt complications were proportionate ...
Flow dynamics in lumboperitoneal shunts and their implications in vivo
Journal of Neurosurgery, 2009
T he Silastic LP shunt was introduced by Spetzler et al. in 1975 24,25 for the treatment of communicating hydrocephalus. Since then it has been used in the treatment of a host of other conditions including CSF rhinorrhea, normal pressure hydrocephalus, lumbar pseudomeningoceles, and in particular pseudotumour cerebri, where the ventricles are often small and shunt catheter placement is difficult. 3,4,23 Lumboperitoneal shunt placement is a completely extracranial procedure, thus avoiding all of the brain parenchymal damage that may occur during VP shunt insertion. 2,28 Lumboperitoneal shunts are associated with a very low mortality rate compared to VP shunts. 28 In addition, some authors have reported that the overall complication rate with LP shunts was considerably lower than when VP shunts were used. The LP shunt has long been associated with myriad complications. In some series LP shunts required an average of 3 revisions per shunt inserted. 12 Because of the high complication rate of LP shunts, some authors have recommended that they be used only as a last resort in the vast majority of cases. 12 However, medical treatment for pseudotumor cerebri often fails, and adequate weight loss is rarely achieved. One of the major concerns after LP shunt insertion is the development of hindbrain herniation, which can occur in up to 70% of patients in the long term. Associated with this is the development of low pressure symptoms including headaches, dizziness, unsteadiness, and hearing loss, indicating that overdrainage may be a problem in the design of LP shunts. Because LP shunts play an important role in the treatment of patients with pseudotumour cerebri, 28 attempts should be made to improve this device further, before seeking an alternative. We designed a simple experiment to study the flow characteristics of LP shunts in an experimental setting and attempted to determine the optimal catheter length.
Flow dynamics in lumboperitoneal shunts and their implications in vivo: Laboratory investigation
Journal of Neurosurgery, 2009
T he Silastic LP shunt was introduced by Spetzler et al. in 1975 24,25 for the treatment of communicating hydrocephalus. Since then it has been used in the treatment of a host of other conditions including CSF rhinorrhea, normal pressure hydrocephalus, lumbar pseudomeningoceles, and in particular pseudotumour cerebri, where the ventricles are often small and shunt catheter placement is difficult. 3,4,23 Lumboperitoneal shunt placement is a completely extracranial procedure, thus avoiding all of the brain parenchymal damage that may occur during VP shunt insertion. 2,28 Lumboperitoneal shunts are associated with a very low mortality rate compared to VP shunts. 28 In addition, some authors have reported that the overall complication rate with LP shunts was considerably lower than when VP shunts were used. The LP shunt has long been associated with myriad complications. In some series LP shunts required an average of 3 revisions per shunt inserted. 12 Because of the high complication rate of LP shunts, some authors have recommended that they be used only as a last resort in the vast majority of cases. 12 However, medical treatment for pseudotumor cerebri often fails, and adequate weight loss is rarely achieved. One of the major concerns after LP shunt insertion is the development of hindbrain herniation, which can occur in up to 70% of patients in the long term. Associated with this is the development of low pressure symptoms including headaches, dizziness, unsteadiness, and hearing loss, indicating that overdrainage may be a problem in the design of LP shunts. Because LP shunts play an important role in the treatment of patients with pseudotumour cerebri, 28 attempts should be made to improve this device further, before seeking an alternative. We designed a simple experiment to study the flow characteristics of LP shunts in an experimental setting and attempted to determine the optimal catheter length.
Frequency and causes of shunt revisions in different cerebrospinal fluid shunt types
Acta Neurochirurgica, 1995
Shunt complications and revisions are common in hydrocephalic patients treated with a ventriculo-atrial or a ventriculo-peritoneal shunt. The reported revision rate differs very much but the rate of revision is close to 50% in many papers. Data from 884 hydrocephalic patients treated with various shunt types in the period 1958-1989 were recorded retrospectively in order to evaluate the frequency of revision for various shunt types and secondly to analyse the specific reasons for the shunt revisions. The rate of shunt revision was 45%. The Pudenz shunt was revised more often (62%) than the remaining shunt types. The Hakim and the Orbis-Sigma shunts had fewer revisions (35% and 27%, respectively) than the other observed shunt types. A defect of or an obstruction in the venfficular catheters was a frequent cause of revision followed by a defect or an obstruction of the distal catheter, a displacement of the distal catheter and an acute infection. Because of the higher rate of revision for the Pudenz shunt the rate of the above mentioned specific complications is also higher in most of the subgroups for that specific shunt type. Driven by these experiences it is reasonable to seek to develop and introduce new shunt types in an attempt to reduce the complication rate.