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Sample records for acute shunt malfunction

  1. Episodic ventriculomegaly due to hypernatremia mimicking shunt malfunction: case report.

    Jernigan, Sarah C; Stone, Scellig S D; Aronson, Joshua P; Putman, Melissa; Proctor, Mark R

    2015-10-01

    Patients with shunted hydrocephalus presenting with altered mental status and ventriculomegaly are generally considered to be in shunt failure requiring surgical treatment. The authors describe a case of shunted hydrocephalus secondary to a disseminated neuroectodermal tumor in a pediatric patient in whom rapid fluctuations in sodium levels due to diabetes insipidus repeatedly led to significant changes in ventricle size, with invasively confirmed normal shunt function and low intracranial pressure. This clinical picture exactly mimics shunt malfunction, requires urgent nonsurgical therapy, and underscores the importance of considering serum osmolar abnormalities in the differential diagnosis for ventriculomegaly. PMID:26186358

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

    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. PMID:26636251

  3. Ventricular enlargement due to acute hypernatremia in a patient with a ventriculoperitoneal shunt.

    Andres, Robert H; Pendharkar, Arjun V; Kuhlen, Dominique; Mariani, Luigi

    2010-07-01

    Patients requiring CSF shunts frequently have comorbidities that can influence water and electrolyte balances. The authors report on a case involving a ventriculoperitoneal shunt in a patient who underwent intravenous hyperhydration and withdrawal of vasopressin substitution prior to scheduled high-dose chemotherapy regimen for a metastatic suprasellar germinoma. After acute neurological deterioration, the patient underwent CT scanning that demonstrated ventriculomegaly. A shunt tap revealed no flow and negative opening pressure. Due to suspicion of proximal shunt malfunction, the comatose patient underwent immediate surgical exploration of the ventricle catheter, which was found to be patent. However, acute severe hypernatremia was diagnosed during the procedure. After correction of the electrolyte disturbances, the patient regained consciousness and made a good recovery. Although rare, the effects of acute severe hypernatremia on brain volume and ventricular size should be considered in the differential diagnosis of ventriculoperitoneal shunt failure. PMID:19911884

  4. Laparoscopic Cholecystectomy for Acute Calcular Cholecystitis in a Patient with Ventriculoperitoneal Shunt: A Case Report and Literature Review

    Abdullah A. Albarrak

    2015-01-01

    Full Text Available Management of patients who have ventriculoperitoneal shunt presenting with acute calcular cholecystitis has remained a clinical challenge. In this paper, the hospital course and the follow-up of a patient presenting with acute calcular cholecystitis and ventriculoperitoneal shunt managed with laparoscopic cholecystectomy are presented followed by literature review on the management of acute calcular cholecystitis in patients who have ventriculoperitoneal shunts.

  5. Effect of Prone Position on Regional Shunt, Aeration, and Perfusion in Experimental Acute Lung Injury

    Richter, Torsten; Bellani, Giacomo; Harris, R. Scott; Melo, Marcos F. Vidal; Winkler, Tilo; Venegas, Jose G.; Musch, Guido

    2005-01-01

    Rationale: The prone position is used to improve gas exchange in patients with acute respiratory distress syndrome. However, the regional mechanism by which the prone position improves gas exchange in acutely injured lungs is still incompletely defined. Methods: We used positron emission tomography imaging of [13N]nitrogen to assess the regional distribution of pulmonary shunt, aeration, perfusion, and ventilation in seven surfactant-depleted sheep in supine and prone positions. Results: In t...

  6. Emergency management of an acute tension pneumocephalus following ventriculoperitoneal shunt surgery for normal pressure hydrocephalus.

    Aydoseli, Aydın; Akcakaya, Mehmet Osman; Aras, Yavuz; Boyali, Osman; Unal, Omer Faruk

    2013-01-01

    Tension pneumocephalus is a rare and life threatening complication of intracranial surgical procedures, and requires immediate recognition and surgical intervention. Tension pneumocephalus following ventriculoperitoneal shunt surgery is extremely rare and commonly seen as a delayed complication. To our knowledge, early postoperative tension pneumocephalus after shunt surgery was reported only in one other publication. We present a case of acute tension pneumocephalus following ventriculoperitoneal shunt surgery for normal pressure hydrocephalus, which was managed well with close neurological follow-up and rapid surgical intervention. The use of the portable CT scanner in this case saved significant time, without the transport of the patient to the radiology unit, made early surgical intervention possible, and prevented morbidity and mortality. PMID:24101285

  7. Rapid resolution of an acute subdural hematoma by increasing the shunt valve pressure in a 63-year-old man with normal-pressure hydrocephalus with a ventriculoperitoneal shunt: a case report and literature review

    Hayes Jackson

    2012-11-01

    Full Text Available Abstract Introduction Symptomatic subdural hematoma development is a constant concern for patients who have undergone cerebrospinal fluid shunting procedures to relieve symptoms related to normal-pressure hydrocephalus. Acute subdural hematomas are of particular concern in these patients as even minor head trauma may result in subdural hematoma formation. The presence of a ventricular shunt facilitates further expansion of the subdural hematoma and often necessitates surgical treatment, including subdural hematoma evacuation and shunt ligation. Case presentation We present the case of a 63-year-old North American Caucasian man with normal-pressure hydrocephalus with an adjustable valve ventriculoperitoneal shunt who developed an acute subdural hematoma after sustaining head trauma. Conservative treatment was favored over operative evacuation because our patient was neurologically intact, but simple observation was considered to be too high risk in the setting of a low-pressure ventriculoperitoneal shunt. Thus, the valve setting on the ventriculoperitoneal shunt was increased to its maximum pressure setting in order to reduce flow through the shunt and to mildly increase intracranial pressure in an attempt to tamponade any active bleeding and limit hematoma expansion. A repeat computed tomography scan of the head six days after the valve adjustment revealed complete resolution of the acute subdural hematoma. At this time, the valve pressure was reduced to its original setting to treat symptoms of normal-pressure hydrocephalus. Conclusions Programmable shunt valves afford the option for non-operative management of acute subdural hematoma in patients with ventricular shunts for normal-pressure hydrocephalus. As illustrated in this case report, increasing the shunt valve pressure may result in rapid resolution of the acute subdural hematoma in some patients.

  8. Acute intraoperative neurogenic myocardial stunning during intracranial endoscopic fenestration and shunt revision in a pediatric patient.

    Dragan, Kristen Elizabeth; Patten, William D; Elzamzamy, Osama M; Attaallah, Ahmed Fikry

    2016-02-01

    Neurogenic stunned myocardium (NSM) is syndrome of myocardial dysfunction following an acute neurological insult. We report a case of NSM that occurred intraoperatively in a pediatric patient undergoing endoscopic fenestration and shunt revision. Accidental outflow occlusion of irrigation fluid and ventricular distension resulted in an acute increase in heart rate and arterial blood pressure. Subsequently, the patient developed stunned myocardium with global myocardial hypokinesia and pulmonary edema. She was promptly treated intraoperatively then admitted to the pediatric intensive care unit with resolution of her symptoms within 12 h. She was later discharged to home on the fourth postoperative day. In the current endoscopic era, this report highlights the possibility of intraoperative NSM and neurogenic pulmonary edema in the pediatric population. Early detection and treatment with a team approach help to achieve optimal control of this life-threatening condition and improve the outcome. PMID:26314948

  9. Use of a stop-flow programmable shunt valve to maximize CNS chemotherapy delivery in a pediatric patient with acute lymphoblastic leukemia

    Sheri K Palejwala

    2014-01-01

    Full Text Available Background: The requirement for frequent intraventricular drug delivery in the setting of shunt dependence is particularly challenging in the treatment of central nervous system infection, neoplastic disease, and hemorrhage. This is especially relevant in the pediatric population where both hematogenous malignancy requiring intrathecal drug delivery and shunt-dependent hydrocephalus are more prevalent. Intrathecal and intraventricular chemotherapy agents can be prematurely diverted in these shunt-dependent patients. Case Description: We report the use of a stop-flow programmable shunt valve to maximize delivery of intraventricular chemotherapy in a child with acute lymphoblastic leukemia and disseminated intravascular coagulation who presented with spontaneous intracerebral and intraventricular hemorrhages. The patient then developed posthemorrhagic hydrocephalus and eventually progressed to shunt dependence but still required frequent intraventricular chemotherapy administration. A ventriculoperitoneal shunt, equipped with a valve that allows for near cessation of cerebrospinal fluid flow (Certas; , Codman, Raynham, MA, and a contralateral Ommaya reservoir were inserted to maximize intraventricular dissemination of chemotherapy. Conclusions: To the best of our knowledge, this is the first reported case of the use of a high-resistance programmable valve being used to virtually cease cerebrospinal fluid flow through the distal catheter temporarily in order to maximize intraventricular drug dissemination in a pediatric patient with acute lymphoblastic leukemia.

  10. Transjugular Intrahepatic Portosystemic Shunt, Mechanical Aspiration Thrombectomy, and Direct Thrombolysis in the Treatment of Acute Portal and Superior Mesenteric Vein Thrombosis

    A patient was admitted because of severe abdominal pain, anorexia, and intestinal bleeding. Contrast-enhanced multidetector computed tomography demonstrated acute portal and superior mesenteric vein thrombosis (PSMVT). The patient was treated percutaneously with transjugular intrahepatic portosystemic shunt (TIPS), mechanical aspiration thrombectomy, and direct thrombolysis, and 1 week after the procedure, complete patency of the portal and superior mesenteric veins was demonstrated. TIPS, mechanical aspiration thrombectomy, and direct thrombolysis together are promising endovascular techniques for the treatment of symptomatic acute PSMVT

  11. Factors affecting ventriculoperitoneal shunt survival in adult patients

    Farid Khan

    2015-01-01

    Conclusions: Patients with increased age, prolonged hospital stay, GCS score of less than 13, extra-ventricular drains in situ, or excision of brain tumors were more likely to experience early shunt malfunction.

  12. On malfunctioning software

    Floridi, Luciano; Fresco, Nir; Primiero, Giuseppe

    2015-01-01

    Artefacts do not always do what they are supposed to, due to a variety of reasons, including manufacturing problems, poor maintenance, and normal wear-and-tear. Since software is an artefact, it should be subject to malfunctioning in the same sense in which other artefacts can malfunction. Yet, whether software is on a par with other artefacts when it comes to malfunctioning crucially depends on the abstraction used in the analysis. We distinguish between “negative” and “positive” notions of ...

  13. Ventriculoperitoneal shunt infections

    Sarguna P

    2006-01-01

    Full Text Available Central nervous system (CNS shunt infection is a cause of significant morbidity, causing shunt malfunction and chronic ill health. This study was carried out to evaluate the infection rate associated with CNS shunts, assess the frequency of the pathogens as well as their antibiotic sensitivity pattern aiming at suitable prophylaxis. A retrospective analysis of 226 CSF cerebrospinal fluid (CSF shunt procedures sent for bacteriological work up over a period of one year and six months was undertaken. Laboratory diagnosis was established by subjecting the CSF to cell count, biochemical tests, bacteriological culture and antibiotic susceptibility test. Nine out of 226(3.98% of the CSF samples were culture positive. Coagulase negative Staphylococcus was the most common isolate accounting for 36.36%. Majority of the isolates were sensitive to the thirdgeneration cephalosporins and quinolones. The antibiotic sensitivity pattern suggests cephalosporins and quinolones to be a better choice of antibiotics either prophylactically or therapeutically, which may result in effective and rapid sterilisation of the CSF.

  14. Spontaneous knot; a rare cause of ventriculoperitoneal shunt blockage.

    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.

  15. Spontaneous knot; a rare cause of ventriculoperitoneal shunt blockage.

    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.

  16. Hemi-Fontan or Bidirectional Cavopulmonary Shunt for Right Ventricular Failure after Mitral Valve Replacement and Acute Ascending Aortic Dissection: Report of Two Cases

    Hassan Teimouri

    2015-10-01

    Full Text Available Right ventricular failure due to right coronary artery disease, right ventricular hypertrophy, stunning, abnormal septal motion, myocardial infarction, or non-homogeneous distribution of cardioplegia is an uncommon but serious complication of open heart surgery. We report a patient with severe right ventricular hypertrophy secondary to severe mitral valve stenosis and another patient with detachment of the right coronary artery due to the dissection of the ascending aorta. The patients developed right ventricular failure, which persisted after surgery and rendered weaning from cardiopulmonary bypass unsuccessful. Through a hemi-Fontan, or bidirectional cavopulmonary shunt, and an intra-aortic balloon pump, the patients were successfully weaned from cardiopulmonary bypass. This shunt may be an alternative to a right ventricular assist device in some patients with right ventricular failure. The long-term outcome and the indication of bi-directional cavopulmonary shunt has not been confirmed, although it is believed to be effective for saving the life of patients with low cardiac output and acute right ventricular failure. In our cases, six months following the operation, there was some degree of recovery of the right ventricular function. In long-term follow-up, however, it would be interesting for the authors to know if the improved right ventricular function, with better antegrade pulsatile flow in the pulmonary artery, in any way interferes with the functioning of the bidirectional cavopulmonary shunt.

  17. Ventriculoperitoneal shunt

    ... belly. A small hole is drilled in the skull. A thin tube called a catheter is passed ... of ventriculoperitoneal shunt. In: Jandial R, McCormick PC, Black PM, eds. Core Techniques in Operative Neurosurgery . Philadelphia, ...

  18. Critical ventriculo-peritoneal shunt failure due to peritoneal tuberculosis: Case report and diagnostic suggestions for abdominal pseudocyst

    Hajime Takase

    2014-01-01

    Full Text Available Background: Tuberculous peritonitis (TBP is a well-known complication of ventriculo-peritoneal (VP shunt treatment for hydrocephalus resulting from tuberculous meningitis (TBM. However, a case of hydrocephalus unrelated to TBM resulting from VP shunt malfunction due to TBP has not been reported. Case Description: A 21-year-old male presented with nausea, abdominal pain, and headache. VP and cysto-peritoneal (CP shunts had been inserted to treat hydrocephalus due to a suprasellar arachnoid cyst, replaced the VP and removed the CP in his childhood. Computed tomography demonstrated acute hydrocephalus and an abdominal pseudocyst surrounding the distal end of the peritoneal tube. Initial laboratory data showed elevated white blood cell count and C-reactive protein level, but no causative pathogen was identified. External drainage of cerebrospinal fluid (CSF and of the fluid in the peritoneal cyst was established, and empirical antibiotic therapy was initiated. Bacterial cultures eventually revealed Mycobacterium tuberculosis infection, and TBP was diagnosed. The patient responded well to antituberculosis (anti-TB agents and insertion of a ventriculo-pleural shunt. Conclusion: This case highlights the possibility of CSF shunt failure and concomitant neurological sequelae from TB infection even when the pathogen has not invaded the central nervous system, as in TBM. Moreover, TBP is rare in developed countries and therefore may be misdiagnosed because of nonspecific clinical features and low sensitivity of common TB screening methods.

  19. Acute effects of liver vein occlusion by stent-graft placed in transjugular intrahepatic portosystemic shunt channel: An experimental study

    Keussen, Inger; Bergqvist, Lennart; Rissler, Pehr; Cwikiel, W

    2006-01-01

    The purpose of this study was to evaluate the effects of hepatic vein occlusion by stent-graft used in transjugular intrahepatic portosystemic shunt (TIPS). The experiments were performed in six healthy pigs under general anesthesia. Following percutaneous transhepatic implantation of a port-a-cath in the right hepatic vein, TIPS was created with a stent-graft (Viatorr; W L Gore, Flagstaff, AZ, USA). The outflow from the hepatic vein, blocked by the stent-graft was documented by injection of ...

  20. Transjugular intrahepatic portosystemic shunt.

    Ochs, Andreas

    2005-01-01

    The transjugular intrahepatic portosystemic shunt (TIPS) is an interventional treatment resulting in decompression of the portal system by creation of a side-to-side portosystemic anastomosis. Since its introduction 16 years ago, more than 1,000 publications have appeared demonstrating broad acceptance and increasing clinical use. This review summarizes our present knowledge about technical aspects and complications, follow-up of patients and indications. A technical success rate near 100% and a low occurrence of complications clearly depend on the skills of the operator. The follow-up of the TIPS patient has to assess shunt patency, liver function, hepatic encephalopathy and the possible development of hepatocellular carcinoma. Shunt patency can best be monitored by duplex sonography and can avoid routine radiological revision. Short-term patency may be improved by anticoagulation, while such a treatment does not influence long-term patency. Stent grafts covered with expanded polytetrafluoroethylene show promising long-term patency comparable with that of surgical shunts. With respect to the indications of TIPS, much is known about treatment of variceal bleeding and refractory ascites. The thirteen randomized studies that are available to date show that survival is comparable in patients receiving TIPS or endoscopic treatment for acute or recurrent variceal bleeding. Another group comprises patients with refractory ascites and related complications, such as hepatorenal syndrome and hepatic hydrothorax. It has been demonstrated that TIPS improves these complications. Five randomized studies comparing TIPS with paracentesis and one study comparing TIPS with the peritoneo-venous shunt showed good response of ascites but controversial results on survival. In addition, TIPS has been successfully applied to patients with Budd-Chiari syndrome, portal vein thrombosis, before liver transplantation, and for the treatment of ectopic variceal bleeding. PMID:15920326

  1. Transjugular Intrahepatic Portosystemic Shunt (TIPS): Current Status and Future Possibilities

    Since the insertion of the first TIPS in 1989 much has been learned about this therapeutic procedure. It has an established role for the treatment of some complications of portal hypertension: prevention of recurrent variceal bleeding and rescue of patients with acute uncontrollable variceal bleeding. In addition TIPS is useful for Budd-Chiari syndrome, refractory ascites and hepatorenal syndrome, although its specific role in these indications remains to be definitively established. However, the decrease in sinusoidal blood flow induced by TIPS can lead to the patient developing hepatic encephalopathy and liver failure in some cases. Therefore, TIPS should be used with caution in patients with very poor liver function. From a technical point of view, successful placement of TIPS is achieved in more than 98% of cases by experienced groups. At present, evaluation of TIPS dysfunction based on morphology probably leads to an overdiagnosis of this complication since most of these cases are not associated with clinical manifestations (recurrent bleeding or refractory ascites). The major disadvantage of TIPS remains its poor long-term patency requiring a mandatory surveillance program. The indicator for shunt function/malfunction should be the portosystemic pressure gradient, which is best assessed by intravascular measurements. Shunt obstructions may be prevented or reduced by the use of stent-grafts in the future

  2. Complications of Denver Shunt

    Eranga Perera; Shweta Bhatt; Vikram S Dogra

    2011-01-01

    Hepatic hydrothorax secondary to transdiaphragmatic spread of peritoneal fluid can cause respiratory discomfort to the patient. Draining of hydrothorax helps relieve these symptoms. Pleurovenous shunt (Denver shunt) is a relatively non-invasive method of shunting the pleural fluid to the central venous system. Reported complications of pleurovenous shunts are shunt failure, pulmonary edema, post shunt coagulopathy, deep vein thrombosis, and infection. We report a rare case of a leak at the ve...

  3. A new logic of technical malfunction

    Jespersen, Bjørn; Carrara, Massimiliano

    2013-01-01

    Aim of the paper is to present a new logic of technical malfunction. The need for this logic is motivated by a simple-sounding philosophical question: Is a malfunctioning corkscrew, which fails to uncork bottles, nonetheless a corkscrew? Or in general terms, is a malfunctioning F, which fails to do what Fs do, nonetheless an F? We argue that ‘malfunctioning’ denotes the modifier Malfunctioning rather than a property, and that the answer depends on whether Malfunctioning is subsective or priva...

  4. Acute Effects of Liver Vein Occlusion by Stent-Graft Placed in Transjugular Intrahepatic Portosystemic Shunt Channel: An Experimental Study

    The purpose of this study was to evaluate the effects of hepatic vein occlusion by stent-graft used in transjugular intrahepatic portosystemic shunt (TIPS). The experiments were performed in six healthy pigs under general anesthesia. Following percutaneous transhepatic implantation of a port-a-cath in the right hepatic vein, TIPS was created with a stent-graft (Viatorr; W L Gore, Flagstaff, AZ, USA). The outflow from the hepatic vein, blocked by the stent-graft was documented by injection of contrast medium and repeated injections of 99Tcm-labeled human serum albumin through the port-a-cath. After 2 weeks, the outflow was re-evaluated, the pigs were sacrificed, and histopathologic examination of the liver was performed. Occlusion of the hepatic vein by a stent-graft had a short and temporary effect on the outflow. Histopathological examination from the affected liver segment showed no divergent pattern. Stent-grafts used in TIPS block the outflow from the liver vein, but do not have a prolonged circulatory effect and do not affect the liver parenchyma

  5. Symptomatic spinal cord deformity secondary to a redundant intramedullary shunt catheter

    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 C1-C2 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.)

  6. Complications of Denver Shunt

    Eranga Perera

    2011-01-01

    Full Text Available Hepatic hydrothorax secondary to transdiaphragmatic spread of peritoneal fluid can cause respiratory discomfort to the patient. Draining of hydrothorax helps relieve these symptoms. Pleurovenous shunt (Denver shunt is a relatively non-invasive method of shunting the pleural fluid to the central venous system. Reported complications of pleurovenous shunts are shunt failure, pulmonary edema, post shunt coagulopathy, deep vein thrombosis, and infection. We report a rare case of a leak at the venous end of the catheter that was placed within the right internal jugular vein, resulting in a large collection in the neck.

  7. Distal splenorenal shunt

    ... Surg. 2006 Apr;141(4):385-8. J. Michael Henderson JM, Boyer TD, Kutner MH, et al. Distal splenorenal shunt versus transjugular intrahepatic portal systematic shunt for variceal bleeding: a randomized trial. ...

  8. The presence of a right-to-left shunt is associated with dramatic improvement after thrombolytic therapy in acute ischemic stroke patients

    The efficacy of pharmacological thrombolysis using tissue plasminogen activator (t-PA) depends upon the relative fibrin content of the thrombus. We investigated whether stroke patients with a right-to-left shunt (RLS), whose embolic source was associated with fibrin-rich thrombus formed in the venous system, were more likely to improve dramatically after thrombolytic therapy than those without RLS. Acute stroke patients treated with t-PA were assessed prospectively to determine the clinical factors associated with ''dramatic improvement'' after t-PA administration. ''dramatic improvement'' was defined as a ≥10 point reduction in the total National Institutes of Health Stroke Scale (NIHSS) score or a total NIHSS score of 0 or 1 at 7 days. The presence of an RLS was determined using contrast transcranial Doppler (c-TCD) within 6 hours of stroke onset. Forty eight patients (26 males; mean age: 73.0±10.7 years; baseline NIHSS score, 13.4±6.6) were enrolled. Twenty-one patients had dramatic improvement (D group). c-TCD demonstrated an RLS in 17 (35.4%) patients. On multivariate logistic regression analysis using hyperlipidemia, atrial fibrillation, RLS, diffusion-weighted imaging (DWI)-Alberta Stroke Programme Early CT Score (ASPECTS) (>8), baseline NIHSS score (<10), and glucose (<120 mg/dl) as variables with a P<0.1 on univariate analysis, RLS (odds ratio (OR): 5.9; confidence interval (CI): 1.3-27.3, P=0.022) was the only independent factor associated with dramatic improvement. The presence of an RLS on c-TCD was an independent factor associated with dramatic improvement after t-PA administration. (author)

  9. Urethral protrusion of the abdominal catheter of ventriculoperitoneal shunt: Case report of extremely rare complication

    Ugur Yazar

    2012-01-01

    Full Text Available Hydrocephalus in its various forms constitutes one of the major problems in pediatric neurosurgical practice. The placement of a ventriculoperitoneal (VP shunt is the most common form of treatment for hydrocephalus, so that all neurosurgeons struggle with shunt malfunctions and their complications. Well-known complications are connected with the use of the valve systems (malfunction, infectious, overdrainage, secondary craniosynostosis, etc.. We report an unusual case of protruding abdominal catheter from the urethra. This girl had received a VP shunt for hydrocephalus following surgery of posterior fossa medulloblastoma 4 years ago. After admission, the entire system was removed, antibiotic treatment was administered for 2 weeks, and a new VP shunt was placed. The postoperative course was uneventful. This complication is extremely rare.

  10. Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

    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. PMID:27589973

  11. Early onset tension pneumocephalus following ventriculoperitoneal shunt insertion for normal pressure hydrocephalus: a case report.

    Barada, Wissam; Najjar, Marwan; Beydoun, Ahmad

    2009-04-01

    The occurrence of tension pneumocephalus following ventriculoperitoneal (v.p.) shunt insertion is extremely rare, and is usually of delayed onset. We report a patient who developed an acute subdural tension pneumocephalus within 1 day following placement of a v.p. shunt for normal pressure hydrocephalus as a complication from shunt surgery. PMID:19185417

  12. Endoscopic Third Ventriculostomy in Previously Shunted Children

    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.

  13. Lumbar peritoneal shunt

    Yadav Yad

    2010-01-01

    Full Text Available A lumbar peritoneal (LP shunt is a technique of cerebrospinal fluid (CSF diversion from the lumbar thecal sac to the peritoneal cavity. It is indicated under a large number of conditions such as communicating hydrocephalus, idiopathic intracranial hypertension, normal pressure hydrocephalus, spinal and cranial CSF leaks, pseudomeningoceles, slit ventricle syndrome, growing skull fractures which are difficult to treat by conventional methods (when dural defect extends deep in the cranial base or across venous sinuses and in recurrent cases after conventional surgery, raised intracranial pressure following chronic meningitis, persistent bulging of craniotomy site after operations for intracranial tumors or head trauma, syringomyelia and failed endoscopic third ventriculostomy with a patent stoma. In spite of the large number of indications of this shunt and being reasonably good, safe, and effective, very few reports about the LP shunt exist in the literature. This procedure did not get its due importance due to some initial negative reports. This review article is based on search on Google and PubMed. This article is aimed to review indications, complications, results, and comparison of the LP shunt with the commonly practiced ventriculoperitoneal (VP shunt. Shunt blocks, infections, CSF leaks, overdrainage and acquired Chiari malformation (ACM are some of the complications of the LP shunt. Early diagnosis of overdrainage complications and ACM as well as timely appropriate treatment especially by programmable shunts could decrease morbidity. Majority of recent reports suggest that a LP shunt is a better alternative to the VP shunt in communicating hydrocephalus. It has an advantage over the VP shunt of being completely extracranial and can be used under conditions other than hydrocephalus when the ventricles are normal sized or chinked. More publications are required to establish its usefulness in the treatment of wide variety of indications.

  14. The peritoneo-venous shunts of Le Veen and the testing of its function

    A radio technique for testing the patency of, peritoneo-venous shunts of Le Veen, is reported and is demonstrated by discussing a case history. By now a total number of 16 patients have been tested, after implantation of such a shunt. The demonstrated radioisotope technique, which causes no complaints from the patient, is not only able to inform concerning the functional state of the Le Veen shunts, but also, in case of disturbances, is able to reveal the cause of the underlying malfunctions. (author)

  15. Exit ventriculoperitoneal shunt; enter endoscopic third ventriculostomy (ETV): contemporary views on hydrocephalus and their implications on management

    Kamalo, P

    2013-01-01

    Hydrocephalus has been known to affect humans since the birth of human medicine as it is described by Hippocrates. The management of this condition is however still dodged by challenges due to a poor understanding of its pathophysiology. The ventriculoperitoneal shunt presents considerable problems especially with respect to infection and shunt malfunction. Low income countries, that currently face the greater burden of paediatric hydrocephalus. experience an increased challenge with ventricu...

  16. Shunt tube calcification as a late complication of ventriculoperitoneal shunting.

    Salim, Abubakr Darrag; Elzain, Mohammed Awad; Mohamed, Haddab Ahmed; Ibrahim Zayan, Baha Eldin Mohamed

    2015-01-01

    Shunt calcification is a rare complication of ventriculoperitoneal shunting that occurs years later after the initial operation this condition is rarely reported in literature. Two patients with shunt calcifications were described. The first patient was 17-year-old lady who had congenital hydrocephalus and shunted in the early infancy, she was presented recently complaining of itching of the skin along the shunt track and limitation of neck movement. The patient was then operated with removal of the old peritoneal catheter and replacing it with a new one. The second patient was 17-year-old boy originally was a case of posterior fossa pilocytic astrocytoma associated with obstructive hydrocephalus, he was operated with both shunting for the hydrocephalus and tumor removal, 6 years later he presented with shunt exposure. Calcification of the shunt tube was discovered intraoperatively upon shunt removal. Shunt calcification has been observed mainly in barium-impregnated catheters. Introducing plain silicone-coated shunt tubing may reduce the rate of this condition. The usual complaints of the patients suffering from this condition are pain in the neck and chest wall along the shunt pathway and limitation of the neck movement due to shunt tube tethering, but features of shunt dysfunction and skin irritation above the shunt may be present. In this review, plain X-ray and operative findings showed that the most extensive calcification is present in the neck, where the catheters were subject to heavy mechanical stress. Disturbed calcium and phosphate metabolisms may be involved in this condition. Shunt calcification is a rare condition that occurs due to material aging presenting with features of shunt tethering, dysfunction or overlying skin irritation. Plain X-ray is needed to detect calcification while shunt removal, replacement or endoscopic third ventriculostomy may carry solution for this condition. PMID:26396620

  17. Two Episodes of Ventriculoperitoneal Shunt Migration in a Patient with Idiopathic Intracranial Hypertension

    V. Balakrishnan

    2014-01-01

    Full Text Available Introduction. Ventriculoperitoneal shunts are often placed as treatment for refractory idiopathic intracranial hypertension. Dislodgement and migration of the distal portion of the shunt are more common in obese patients and can be difficult to detect. We report the case of a woman with two separate episodes of shunt migration into her abdominal wall. Case Presentation. We report a case of a 37-year-old female with history of obesity eventually diagnosed with idiopathic intracranial hypertension (IIH as the cause. She failed outpatient therapy and, through neurosurgery, had a VP shunt placed for symptom control. She had subsequent development of worsened symptoms that were found to be due to shunt migration. This happened not once but twice to the same patient. Conclusion. Shunt dislodgement, migration, and subsequent failure are common in obese patients who have shunts placed for IIH. The medical provider should maintain a high index of suspicion for shunt malfunction in these patients, particularly because clinical evaluation may be challenging due to habitus.

  18. Imaging of the ventriculoperitoneal shunt-related complications in infants and children with hydrocephalus

    To evaluate the frequency and imaging findings of various ventriculo-peritoneal shunt-related complications in pediatric patients with hydrocephalus. We retrospectively reviewed 246 plain radiographs, three shuntograms, 53 ultrasounds, 133 CT scans, and 24 MR images obtained before and after the ventriculo-peritoneal shunt procedure in 33 pediatric patients with hydrocephalus. Using preoperative images, the etiology of the hydrocephalus was assessed. Changes in the size and shape of the ventricles, the location and continuity of shunt apparatus, and the presence of any abnormal enhancement, hemorrhage, edema or tissue loss, or other findings of complications, were analyzed on postoperative images ; the frequency and imaging findings of shunt-related complications such as shunt malfunction, infection, homorrhage or isolated ventricle, and complications caused by overdrainage, were thus evaluated. The frequency of such complications was analyzed according to the etiology of the hydrocephalus, and in addition, medical records were reviewed and correlated with imaging findings. In 18 of the 33 patients(54%), a total of 31 complications was detected. These were present in four of five cases (80%) of hydrocephalus caused by meningitis and ventriculitis, seven of twelve (58%) intraventricular hemorrhage, two of four (50%) unknown cases, three of nine (33%) congenital malformations, one of two (50%) tumors, and one (100%) congenital infection. Shunt malfunction was most common (n=15), and was accompanied by findings of enlarged ventricles, periventricular and peritubal edema, and abnormal location of the shunt tube. Symptoms and signs of increased intracranial pressure were also noted. Subdural hemorrhage and infection were present in four cases each ; findings of infection were enhancement of the ventricular wall, meninges, and parenchyma, as well as sonographically noted intraventricular septation and increased ventricular wall echo. Isolated lateral ventricle (n=4) or 4

  19. Neurocomputational Nosology: Malfunctions of Models and Mechanisms

    David L Barack

    2016-05-01

    Full Text Available Executive dysfunctions, psychopathologies arising from problems in the control and regulation of behavior, can occur as a result of the faulty execution of formal information processing models or as a result of malfunctioning neural mechanisms. The models correspond to the formal descriptions of how signals in the environment must be transformed in order to behave adaptively, and the mechanisms correspond to the signal transformations that nervous systems implement in order to execute those cognitive functions. Mechanisms in the form of repeated patterns of neural dynamics execute information processing models. Two distinct modes of malfunction can occur when neural dynamics execute models of information processing. The processing models describing behavior may fail to be executed correctly by neural mechanisms. Or, the neural mechanisms may malfunction, failing to implement the right computation. As an example of malfunctioning models in executive cognition, purported failures of rule following can be understood as failures to appropriately execute a suite of processing models. As an example of malfunctioning mechanisms of executive cognition, maladaptive behavior resulting from dysfunction in the medial prefrontal cortex can be understood as failures in the signal transformations carried out therein. The purpose of these examples is to illustrate the potential benefits of considering models and mechanisms in the diagnosis and etiology of neuropsychological illness and dysfunction, especially disorders of executive cognition.

  20. Neurocomputational Nosology: Malfunctions of Models and Mechanisms.

    Barack, David L; Platt, Michael L

    2016-01-01

    Executive dysfunctions, psychopathologies arising from problems in the control and regulation of behavior, can occur as a result of the faulty execution of formal information processing models or as a result of malfunctioning neural mechanisms. The models correspond to the formal descriptions of how signals in the environment must be transformed in order to behave adaptively, and the mechanisms correspond to the signal transformations that nervous systems implement in order to execute those cognitive functions. Mechanisms in the form of repeated patterns of neural dynamics execute information processing models. Two distinct modes of malfunction can occur when neural dynamics execute models of information processing. The processing models describing behavior may fail to be executed correctly by neural mechanisms. Or, the neural mechanisms may malfunction, failing to implement the right computation. As an example of malfunctioning models in executive cognition, purported failures of rule following can be understood as failures to appropriately execute a suite of processing models. As an example of malfunctioning mechanisms of executive cognition, maladaptive behavior resulting from dysfunction in the medial prefrontal cortex (mPFC) can be understood as failures in the signal transformations carried out therein. The purpose of these examples is to illustrate the potential benefits of considering models and mechanisms in the diagnosis and etiology of neuropsychological illness and dysfunction, especially disorders of executive cognition. PMID:27199835

  1. Neurocomputational Nosology: Malfunctions of Models and Mechanisms

    Barack, David L.; Platt, Michael L.

    2016-01-01

    Executive dysfunctions, psychopathologies arising from problems in the control and regulation of behavior, can occur as a result of the faulty execution of formal information processing models or as a result of malfunctioning neural mechanisms. The models correspond to the formal descriptions of how signals in the environment must be transformed in order to behave adaptively, and the mechanisms correspond to the signal transformations that nervous systems implement in order to execute those cognitive functions. Mechanisms in the form of repeated patterns of neural dynamics execute information processing models. Two distinct modes of malfunction can occur when neural dynamics execute models of information processing. The processing models describing behavior may fail to be executed correctly by neural mechanisms. Or, the neural mechanisms may malfunction, failing to implement the right computation. As an example of malfunctioning models in executive cognition, purported failures of rule following can be understood as failures to appropriately execute a suite of processing models. As an example of malfunctioning mechanisms of executive cognition, maladaptive behavior resulting from dysfunction in the medial prefrontal cortex (mPFC) can be understood as failures in the signal transformations carried out therein. The purpose of these examples is to illustrate the potential benefits of considering models and mechanisms in the diagnosis and etiology of neuropsychological illness and dysfunction, especially disorders of executive cognition. PMID:27199835

  2. A New Logic of Technical Malfunction

    Jespersen, Bjorn; Carrara, M.

    2013-01-01

    Roč. 101, č. 3 (2013), s. 547-581. ISSN 0039-3215 Institutional support: RVO:67985955 Keywords : logic of malfunction * modification * simple type theory * transparent intensional logic * philosophy of technology * artefact * functioning as * intensional essentialism Subject RIV: AA - Philosophy ; Religion Impact factor: 0.330, year: 2013

  3. 40 CFR 63.1272 - Startups, shutdowns, and malfunctions.

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Startups, shutdowns, and malfunctions... Facilities § 63.1272 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods...

  4. 40 CFR 63.1111 - Startup, shutdown, and malfunction.

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Startup, shutdown, and malfunction. 63... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown, and... develop a written startup, shutdown, and malfunction plan that describes, in detail, procedures...

  5. 40 CFR 63.762 - Startups, shutdowns, and malfunctions.

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Startups, shutdowns, and malfunctions... Facilities § 63.762 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of...

  6. Neurocomputational Nosology: Malfunctions of Models and Mechanisms

    Barack, David L.; Platt, Michael L.

    2016-01-01

    Executive dysfunctions, psychopathologies arising from problems in the control and regulation of behavior, can occur as a result of the faulty execution of formal information processing models or as a result of malfunctioning neural mechanisms. The models correspond to the formal descriptions of how signals in the environment must be transformed in order to behave adaptively, and the mechanisms correspond to the signal transformations that nervous systems implement in order to execute those c...

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Transjugular Intrahepatic Portosystemic Shunt (TIPS) Transjugular Intrahepatic Portosystemic Shunt or TIPS is a procedure ...

  8. Congenital extrahepatic portosystemic shunts

    Murray, Conor P.; Yoo, Shi-Joon; Babyn, Paul S. [Department of Diagnostic Imaging, Hospital for Sick Children, 555 University Avenue, M5G 1X8, Toronto, Ontario (Canada)

    2003-09-01

    A congenital extrahepatic portosystemic shunt (CEPS) is uncommon. A type 1 CEPS exists where there is absence of intrahepatic portal venous supply and a type 2 CEPS where this supply is preserved. The diagnosis of congenital portosystemic shunt is important because it may cause hepatic encephalopathy. To describe the clinical and imaging features of three children with CEPS and to review the cases in the published literature. The diagnostic imaging and medical records for three children with CEPS were retrieved and evaluated. An extensive literature search was performed. Including our cases, there are 61 reported cases of CEPS, 39 type 1 and 22 type 2. Type 1 occurs predominantly in females, while type 2 shows no significant sexual preponderance. The age at diagnosis ranges from 31 weeks of intrauterine life to 76 years. Both types of CEPS have a number of associations, the most common being nodular lesions of the liver (n=25), cardiac anomalies (n=19), portosystemic encephalopathy (n=10), polysplenia (n=9), biliary atresia (n=7), skeletal anomalies (n=5), and renal tract anomalies (n=4). MRI is recommended as an important means of diagnosing and classifying cases of CEPS and examining the associated cardiovascular and hepatic abnormalities. Screening for CEPS in patients born with polysplenia is suggested. (orig.)

  9. Outcome analysis of shunt surgery in hydrocephalus

    Ahmed Ashraf

    2009-01-01

    Full Text Available Aim: To study the clinical outcome of shunt surgeries in children suffering from hydrocephalus. Methods: A prospective study of 50 children with hydrocephalus who underwent a ventriculo-peritoneal shunt insertion over a period of two years. These patients were then followed up for shunt related complications, shunt revisions and outcome. Results : Twenty six of the 50 patients (52% suffered from complications. The most common complications were shunt blockage (n=7 and shunt infection (n=6. These complications necessitated repeated shunt revisions. Conclusions: Infective complications of hydrocephalus are more likely to leave behind an adverse neurological outcome in the form of delayed milestones and mental retardation.

  10. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Full Text Available ... considerations. The teddy 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) About this ...

  11. Quadrupole shunt experiments at SPEAR

    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

  12. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Full Text Available ... anti-inflammatory drugs (NSAIDs) or blood thinners several days prior to your procedure and instructed to not ... overnight at the hospital for one or more days. What is Transjugular Intrahepatic Portosystemic Shunt (TIPS)? What ...

  13. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    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) About ...

  14. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Full Text Available ... Shunt or TIPS is a procedure that uses imaging guidance to connect the portal vein to the ... is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as ...

  15. Anatomical Closure of Left-to-Right Shunts in Premature Infants with Bronchopulmonary Dysplasia and Pulmonary Hypertension: A Cautionary Tale

    Dereddy, Narendra R.; Chilakala, Sandeep R.; Divya Rana

    2015-01-01

    Closure of a systemic to pulmonary shunt in premature infants with bronchopulmonary dysplasia may be beneficial, but in the presence of pulmonary hypertension is controversial. Here, we discuss two premature infants with pulmonary hypertension who developed acute pulmonary hypertensive crisis after closure of these shunts and hence advise caution.

  16. Anatomical Closure of Left-to-Right Shunts in Premature Infants with Bronchopulmonary Dysplasia and Pulmonary Hypertension: A Cautionary Tale

    Narendra R. Dereddy

    2015-10-01

    Full Text Available Closure of a systemic to pulmonary shunt in premature infants with bronchopulmonary dysplasia may be beneficial, but in the presence of pulmonary hypertension is controversial. Here, we discuss two premature infants with pulmonary hypertension who developed acute pulmonary hypertensive crisis after closure of these shunts and hence advise caution.

  17. Magnetic fields and intrathecal pump malfunction.

    Huh, Billy; Roldan, Carlos J

    2016-01-01

    Medical technology has impacted the overall life expectancy. Many conditions traditionally considered fatal are now curable. Surviving chronic diseases and aging of the population have increased the number of people with chronic pain. Many devices are also available to manage severe refractory pain. As such, implantable drug-delivery system (IDDS) is a small battery-powered, programmable pump implanted under the subcutaneous tissue of the abdomen and connected to a small catheter tunneled into the spine. Implantable drug-delivery system is used for the administration of morphine, ziconotide, baclofen, or their mixtures into the cerebrospinal fluid. Like many medical devices, IDDS has technical glitch which limits its performance under certain conditions. Implantable drug-delivery system is susceptible to magnetic field such as a magnetic resonance imaging (MRI) which can temporarily stall the rotor of the pump motor and suspend drug delivery. We encountered a patient from out of town seen at emergency department with increased pain and symptoms of opiates withdrawal after intermittent IDDS malfunction. He denied any exposure to magnetic fields or MRI. However, the pump interrogation showed multiple motor stall events in the event log. After a detailed inquiry, the most likely cause of pump malfunction appears to be frequent placement of a laptop computer on his abdomen close to the pump. The magnets in the laptop speakers may have caused the rotor of the pump motor to stall during the computer use, and frequent stall has caused symptoms of withdrawal. No other mechanical failures were found. The patient was discharged home after the symptoms resolved, and the pump was reprogrammed. PMID:26008580

  18. 76 FR 12743 - Medical Device Reporting; Malfunction Reporting Frequency

    2011-03-08

    ... HUMAN SERVICES Food and Drug Administration Medical Device Reporting; Malfunction Reporting Frequency... continue to submit malfunction reports in full compliance with FDA's Medical Device Reporting regulation... supporting, or life sustaining, must continue to report in full compliance with part 803, pending further...

  19. Association of Brucella Meningoencephalitis with Cerebrospinal Fluid Shunt in A Child: A Case Report

    Babak ABDINIA

    2013-01-01

    Full Text Available Brucellosis is an endemic zoonosis in Iran. It is a systemic infection that can involve any organs or systems of the body and have variable presentations. Ventriculoperitoneal (VP shunt infections due to brucellosis have been rarely reported in the literatures.This is the history of a four years old boy who developed Brucella meningoencephalitis at the age of 42 months, whilst he had a VP shunt in situ for hydrocephalus treatment. Also, he presented brucellosis as acute abdomen. This patient was treated with trimethoprim-sulfamethoxazole, gentamicin and rifampicin. The shunt was extracted and all clinical and laboratory test abnormalities subsided through this management.We propose that in a patient with Brucella meningoencephalitis, the cerebrospinal fluid shunt system can be extracted and treatment with appropriate combination of antibiotics could be successful. Moreover, it shows that brucellosis should be considered in the differential diagnosis for acute abdomen and ascites in endemic regions.

  20. Control Rod Malfunction at the NRAD Reactor

    Thomas L. Maddock

    2010-05-01

    The neutron Radiography Reactor (NRAD) is a training, research, and isotope (TRIGA) reactor located at the INL. The reactor is normally shut down by the insertion of three control rods that drop into the core when power is removed from electromagnets. During a routine shutdown, indicator lights on the console showed that one of the control rods was not inserted. It was initially thought that the indicator lights were in error because of a limit switch that was out of adjustment. Through further testing, it was determined that the control rod did not drop when the scram switch was initially pressed. The control rod anomaly led to a six month shutdown of the reactor and an in depth investigation of the reactor protective system. The investigation looked into: scram switch operation, console modifications, and control rod drive mechanisms. A number of latent issues were discovered and corrected during the investigation. The cause of the control rod malfunction was found to be a buildup of corrosion in the control rod drive mechanism. The investigation resulted in modifications to equipment, changes to both operation and maintenance procedures, and additional training. No reoccurrences of the problem have been observed since corrective actions were implemented.

  1. Orthopaedic complications of lumboperitoneal shunts.

    McIvor, J; Krajbich, J I; Hoffman, H

    1988-01-01

    Lumboperitoneal (LP) shunts performed for communicating hydrocephalus have been reported to lead to neurologic deficits in the lower limbs and spinal deformities as a result of arachnoiditis. A chart review of 375 children who underwent LP shunts between 1960 and 1981 at The Hospital For Sick Children in Toronto was undertaken. Of the 375 charts reviewed, evidence of shunt-induced neurologic deficits was seen in 63 patients. Thirty-four patients had back pain with or without sciatica, 45 patients had hamstring tightness, and 40 patients had foot deformities. Forty-nine patients had lumbar hyperlordosis, lordoscoliosis, and scoliosis. These deformities are postulated to be the result of arachnoiditis involving the conus medullaris and lower lumbar roots. PMID:3192696

  2. Candidal infections of ventriculoperitoneal shunts

    V P Baradkar

    2009-01-01

    Full Text Available Although ventriculoperitoneal (VP shunt infection is a common complication of shunt procedures, fungal infection is considered to be rare. In the present study, we performed retrospective analysis of six cases in which candida infection occurred. In all these six cases, VP shunt was performed in children for hydrocephalus and the onset of symptoms varied between seven days to one month after the surgical procedure was performed. The commonest clinical signs and symptoms were fever (100%, vomiting (100%, and altered sensorium (50%. The commonest isolate was Candida albicans (66.66% followed by Candida parapsilosis and Candida glabrata in one case each. All the patients were successfully treated with Amphotericin B and there was no mortality recorded.

  3. Piezoelectric RL shunt damping of flexible structures

    Høgsberg, Jan Becker; Krenk, Steen

    2015-01-01

    Resonant RL shunt circuits represent a robust and effective approach to piezoelectric damping, provided that the individual shunt circuit components are calibrated accurately with respect to the dynamic properties of the corresponding flexible structure. The balanced calibration procedure applied...

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

    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.

  5. Percutaneous Transjugular Direct Porto-caval Shunt in Patients with Budd-Chiari Syndrome

    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

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

    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

  7. Severe respiratory failure following ventriculopleural shunt

    Shahzad Alam; Manjunath, Nagaraju M.

    2015-01-01

    Cerebrospinal fluid (CSF) diversion procedure has been used for long to treat hydrocephalus in children. The principle of shunting is to establish a communication between the CSF and a drainage cavity (peritoneum, right atrium, and pleura). Ventriculoperitoneal shunt is used most commonly, followed secondly by ventriculopleural shunt (VPLS). Hydrothorax due to excessive CSF accumulation is a rare complication following both the type of shunts and is more frequently seen with VPLS. We report a...

  8. Scintigraphic demonstration of the permeability of peritoneo-caval shunts (Denver's shunts)

    The functional ability of a peritoneo-caval shunt ('Denver's' Shunt) can be examined in a physiological manner by means of nuclear medical procedures. For this purpose macroaggregated albumin particles used for lung scintigraphy are injected intraperitoneally. The visualization of these particles within the lung capillaries, combined with the possibility of recording a lung perfusion scintigram, gives evidence of the regular function of the shunt. In many cases, scintigraphy also reveals the course of the shunt itself. This enables the shunt to be saved because shunt puncture is not necessary. Such puncture would be required only for X-ray localisation using contrast media in cases of proven shunt occlusion. (orig.)

  9. Automatic detection and analysis of nuclear plant malfunctions

    In this paper a system is proposed, which performs dynamically the detection and analysis of malfunctions in a nuclear plant. The proposed method was developed and implemented on a Reactor Simulator, instead of on a real one, thus allowing a wide range of tests. For all variables under control, a simulation module was identified and implemented on the reactor on-line computer. In the malfunction identification phase all modules run separately, processing plant input variables and producing their output variable in Real-Time; continuous comparison of the computed variables with plant variables allows malfunction's detection. At this moment the second phase can occur: when a malfunction is detected, all modules are connected, except the module simulating the wrong variable, and a fast simulation is carried on, to analyse the consequences. (author)

  10. Fibrous capsule formation of the peritoneal catheter tip in ventriculoperitoneal shunt: Two case reports

    Tomoaki Kano

    2014-01-01

    Full Text Available Background: A fibrous capsule formation of a peritoneal catheter tip has not previously been researched as a complication of ventriculoperitoneal (VP shunts. Case Description: Two adult patients who had undergone a VP shunt for communicative hydrocephalus following subarachnoid hemorrhage caused by a ruptured aneurysm have been identified with malfunction of the VP shunt system by mild disturbance of consciousness and gait disturbance or loss of appetite. Hydrocephalus was diagnosed by computed tomography and the obstruction of the peritoneal catheter was revealed by shuntgraphy. Laparoscopy was performed and the peritoneal catheter tips were obstructed by fibrous white capsules that covered them. One was a thin membranous capsule like a stocking with two small endoluminal granulomas of the peritoneal catheter, and other one was a fibrous glossy white capsule like a sock. These fibrous capsules were excised by laparoscopy forceps without the conversion to a new peritoneal catheter. Following the procedure, the shunt functioned normally. The pathological diagnoses were peritoneum with foreign body reaction or hyalinization of membranous tissue surrounded by fibrous tissue. Conclusion: These fibrous capsules might be formed by the peritoneal reaction to cerebrospinal fluid as a foreign material. As such, a periodic medical check should be scheduled since a fibrous capsule of the peritoneal catheter tip might be formed again.

  11. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Full Text Available ... overnight at the hospital for one or more days. What is Transjugular 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 ...

  12. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Full Text Available ... Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Transjugular Intrahepatic Portosystemic Shunt ( ... blood pressure and pulse during the procedure. A nurse or technologist will insert an intravenous (IV) line ...

  13. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Full Text Available ... What are the limitations of TIPS? What is a Transjugular Intrahepatic Portosystemic Shunt (TIPS)? A transjugular intrahepatic ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  14. Percutaneous transhepatic portacaval shunt (PTPS)

    Objective: To present a latest procedures for portal hypertension with preliminary results and evaluate the technical feasibility and efficacy of the portacaval shunt creation through percutaneous transhepatic approach with its potential clinical significance. Methods: Nineteen patients with portal hypertension (17 men; mean age 57 years, range 32-73) were referred for PTPS procedure because of bleeding varices (n=16), intractable ascites (n=2), and hepatopulmonary syndrome (n=1). The severity of liver disease was Child's B in 4 and Child's C in 15. The PTPS was created by a percutaneous transhepatic puncture through left portal vein to the IVC and a polytetrafluoroethylene (PTFE) stent-grafts was placed through a transhepatic approach. Results: Technical and functional successes were achieved in all patients-arerage without any procedure-related complications. The postprocedural portal vein-IVC gradients decreased with a mean 13 cmH2O and with average 216 days of follow-up showing no recurrent variceal bleeding and refractory ascites. The primary patency ratefor 365 days was 94.8%, obviously higher than classical TIPS. Conclusions: Portacaval shunt creation using the percutaneous transhepatic technique is secure and feasible with favorable primary patency due to the a straight line shunt construction and provide a good alternative to the standard portosystemic shunt in difficult or impossible circumstances. (authors)

  15. 30 CFR 75.352 - Actions in response to AMS malfunction, alert, or alarm signals.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions in response to AMS malfunction, alert... § 75.352 Actions in response to AMS malfunction, alert, or alarm signals. (a) When a malfunction, alert... of a malfunction, alert, or alarm signal, appropriate personnel must promptly initiate...

  16. Ectopic cystoperitoneal shunt demonstrated by valvulography. A case report

    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

  17. Effect of peritoneo-venous shunt on portal pressure.

    Samanta, A K; Leevy, C M

    1989-01-01

    The cause of variceal bleed after a peritoneo-venous shunt is not known. Portal haemodynamic consequences of a peritoneo-venous shunt are poorly understood. The most critical period after a peritoneo-venous shunt is the early postoperative period when rapid mobilisation of peritoneal fluid occurs. Serial changes in the portal pressure during the early postoperative period have not been recorded. In the present study preoperative wedge hepatic vein (WHV), right atrial (RA) and pulmonary capillary wedged (PCW) pressures, cardiac index (CI), and plasma volume (PV) were measured in five alcoholic cirrhotic patients with tense ascites for up to 20 hours postoperatively. The longterm effect was assessed by repeating the intrahepatic and/or wedged hepatic vein pressures in three of the surviving patients after 10 to 20 months. A significant increase in the circulatory dynamics and portal pressure was seen within two hours after shunt placement. Wedged hepatic vein pressure increased from 27.6 (8.2) mmHg to 37.2 (9.2) mmHg (p less than 0.01), RA pressure increased from 6.8 (1.5) mmHg to 14.0 (4.3) mmHg (p less than 0.05), PCW increased from 7.2 (3.5) mmHg to 19.3 (5.7) mmHg (p less than 0.01), CI increased from 3.4 (0.27) lit/m2/min to 4.3 (0.85) lit/m2/min (p less than 0.05). This was accompanied by a 34% increase in the plasma volume from 1838.5 (142.1) to 2471.4 (210) ml/m2. These derangements were maintained up to 20 hours postoperatively. After 10 to 20 months, repeat measurements revealed a return to preoperative measurements. It is concluded that there is an acute increase portal pressure after a peritoneo-venous shunt attributed to increased circulation plasma volume, resulting from rapid mobilisation of ascitic fluid after the shunt. A sudden increase in portal pressure might be an important provoking factor for variceal bleeding after peritoneo-venus shunt. PMID:2920931

  18. Detection of thermocouple malfunction in the Beacon system

    The BEACON system uses Core Exit Thermocouples (T/C) extensively for continuous radial power distribution monitoring. The T/C's are used to adjust the reference power distribution generated by the BEACON system to match the current radial power distribution. T/C reliability, repeatability, and relative accuracy have been very satisfactory. However, it is very important to detect any T/C malfunctions during operation, since a T/C signal change caused by an undetected malfunction can lead to serious errors in the radial power distribution developed by BEACON. A simple procedure has been developed which is capable of discriminating between changes in T/C signals caused by actual changes in reactor conditions and signal changes caused by T/C malfunctions

  19. Cross-sectional imaging of thoracic and abdominal complications of cerebrospinal fluid shunt catheters.

    Bolster, Ferdia; Fardanesh, Reza; Morgan, Tara; Katz, Douglas S; Daly, Barry

    2016-04-01

    This study aims to review the imaging findings of distal (thoracic and abdominal) complications related to ventriculo-peritoneal (VP), ventriculo-pleural (VPL), and ventriculo-atrial (VA) cerebrospinal fluid (CSF) shunt catheter placement. Institution review board-approved single-center study of patients with thoracic and abdominal CSF catheter-related complications on cross-sectional imaging examinations over a 14-year period was performed. Clinical presentation, patient demographics, prior medical history, and subsequent surgical treatment were recorded. The presence or absence of CSF catheter-related infection and/or acute hydrocephalus on cross-sectional imaging was also recorded. There were 81 distal CSF catheter-related complications identified on 47 thoracic or abdominal imaging examinations in 30 patients (age 5-80 years, mean 39.3 years), most often on CT (CT = 42, MRI = 1, US = 4). Complications included 38 intraperitoneal and 11 extraperitoneal fluid collections. Extraperitoneal collections included nine abdominal wall subcutaneous (SC) pseudocysts associated with shunt migration and obesity, an intrapleural pseudocyst, and a breast pseudocyst. There were also two large VPL-related pleural effusions, a fractured catheter in the SC tissues, and a large VA shunt thrombus within the right atrium. Ten patients (33.3 %) had culture-positive infection from CSF or shunt catheter samples. Ten patients (33.3 %) had features of temporally related acute or worsening hydrocephalus on neuroimaging. In four of these patients, the detection of thoracic and abdominal complications on CT preceded and predicted the findings of acute hydrocephalus on cranial imaging. Thoracic and abdominal complications of CSF shunts, as can be identified on CT,  include shunt infection and/or obstruction, may be both multiple and recurrent, and may be predictive of concurrent acute intracranial problems. PMID:26610766

  20. Intra-abdominal metastasis of an intracranial germinoma via ventriculo-peritoneal shunt in a 13-year-old female.

    Murray, Matthew J; Metayer, Lucy E; Mallucci, Conor L; Hale, Juliet P; Nicholson, James C; Kirollos, Ramez W; Burke, G A Amos

    2011-12-01

    A 13-year-old patient presented with massive intra-abdominal metastasis and spontaneous acute tumour lysis syndrome, 17-months after VP shunt placement for metastatic pineal germinoma treated with cranio-spinal-irradiation. Hyperhydration/rasburicase improved renal function, allowing chemotherapy with subsequent surgery. The patient remains event-free 34-months later. Risk of intra-abdominal metastasis from VP shunts is discussed. PMID:21501064

  1. Right Lower Quadrant Abdominal Pain in a Patient with Prior Ventriculoperitoneal Shunting: Consider the Tip!

    Petros Charalampoudis

    2012-01-01

    Full Text Available Introduction. Ventriculoperitoneal (VP shunting is the treatment of choice for nonobstructive hydrocephalus. In patients with such a device, right lower quadrant abdominal pain can puzzle the surgeon, posing a differential diagnostic problem among appendicitis, nonsurgical colicky pain, and primary shunt catheter tip infection. Treatment is different in either case. Presentation of Case. We hereby present a case of a young woman with prior ventriculoperitoneal shunt positioning who presented to our department with right lower quadrant abdominal pain. The patient underwent a 24-hour observation including a neurosurgery consult in order to exclude acute appendicitis and VP shunt tip infection. Twenty four hours later, the patient’s symptomatology improved, and she was discharged with the diagnosis of atypical colicky abdominal pain seeking a gastroenterologist consult. Discussion. This case supports that when a patient with prior VP shunting presents with right lower quadrant abdominal pain, differential diagnosis can be tricky for the surgeon. Conclusion. Apart from acute appendicitis, primary or secondary VP catheter tip infection must be considered because the latter can be disastrous.

  2. Scintigraphic demonstration of the permeability of peritoneo-caval shunts (Denver's shunts)

    Grehn, S.; Pingel, B.

    1988-02-01

    The functional ability of a peritoneo-caval shunt ('Denver's' Shunt) can be examined in a physiological manner by means of nuclear medical procedures. For this purpose macroaggregated albumin particles used for lung scintigraphy are injected intraperitoneally. The visualization of these particles within the lung capillaries, combined with the possibility of recording a lung perfusion scintigram, gives evidence of the regular function of the shunt. In many cases, scintigraphy also reveals the course of the shunt itself. This enables the shunt to be saved because shunt puncture is not necessary. Such puncture would be required only for X-ray localisation using contrast media in cases of proven shunt occlusion.

  3. Method of diagnosis of functional intrapulmonary shunts

    A method of diagnosing functional intrapulmonary shunts is suggested, that permits to obtain the data on the amount, localization and sizes of shunts. This method can be used in the clinic of internal deseases to determine the state of cardiopulmonary patients

  4. 49 CFR 236.56 - Shunting sensitivity.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  5. 49 CFR 234.229 - Shunting sensitivity.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.229 Shunting sensitivity. Each highway-rail...

  6. Performance of piezoelectric shunts for vibration reduction

    This work addresses passive reduction of structural vibration by means of shunted piezoelectric patches. The two classical resistive and resonant shunt solutions are considered. The main goal of this paper is to give closed-form solutions to systematically estimate the damping performances of the shunts, in the two cases of free and forced vibrations, whatever the elastic host structure is. Then it is carefully demonstrated that the performance of the shunt, in terms of vibration reduction, depends on only one free parameter: the so-called modal electromechanical coupling factor (MEMCF) of the mechanical vibration mode to which the shunts are tuned. Experiments are proposed and an excellent agreement with the model is obtained, thus validating it. (paper)

  7. Radioisotopic evaluation of peritoneo-venous shunt patency by intraperitoneal injection of 99m-Tc-human albumin microspheres

    The results demonstrate that 99m Tc-human albumin microspheres always reach the lungs when the shunt is patent. On the contrary, in presence of malfunctioning, they are either confined below the diaphragm or stopped at some point along the tube according to the site of interruption, either in the valve or in venous limb of the shunt. A second injection of the tracer directly into the subcutaneous portion of the tube, immediately above the valve, proved to be very useful to confirm the valvular site of obstruction. The early visualization of the tube seems to indicate a normal flow through the valve even when the last segment of the shunt is obstructed. A poor image of the tube and a delayed accumulation of the tracer in the lungs could indicate the presence of a nonfunctioning valve; in this case, however, an associated heart disease must be ruled out. The present radioisotopic technique prompts early surgical revision when the shunt is not patent. Although the site of interruption can not be exactly determined, the method discriminates between valve and tube shut-off, thus avoiding the replacement of the whole apparatus. This radioisotopic method should be used routinely for the control of PVS patency in cirrhotic patients. Though slightly invasive, it is simple and time-saving. Finally, 99m Tc-human albumin microspheres are useful radioactive tracers because of their easy passage into the LeVeen tube and their homogeneous diffusion in the lungs

  8. [Systemic-pulmonary artery shunt using Golaski graft: trial for measurement of the shunt flow].

    Togo, T; Ito, T; Hata, M; Murata, S; Osaka, K; Komatsu, T; Tabayashi, K; Haneda, K; Mohri, T

    1995-03-01

    For the systemic-pulmonary artery shunt operation, the modified Blalock-Taussig shunt was the first choice for procedure in our institution. Since 1990, Golaski knitted Dacron graft (4 or 5 mm in diameter) was used for the prosthesis. Ex-vivo flow calibration of the electromagnetic flow meter (Nihon Koden, MFV-3100) to Golaski graft showed good correlation between the real flow and value measured by the electromagnetic flow meter. Shunt flow was measured in the consecutive clinical fifteen cases. The shunt flow per body surface area of the patient who required additional shunt operation was 721 ml/min/m2 and one patient in whom the congestive heart failure developed after the shunt operation, had the shunt flow of 3,022 ml/min/m2. The adequate shunt flow in these cases was ranged from 745 to 2,820 ml/min/m2 (mean +/- 1 SD, 1,490 +/- 587.8). Therefore we performed the systemic-pulmonary artery shunt operation using Golaski graft to get the shunt flow of 1,000 ml/min/m2 (approximately a third of cardiac index) for the guide of good results. PMID:7897896

  9. Preoperative shunts in thalamic tumours.

    Goel A

    2000-10-01

    Full Text Available Thirty one patients with thalamic glioma underwent a pre-tumour resection shunt surgery. The procedure was uneventful in 23 patients with relief from symptoms of increased intracranial pressure. Eight patients worsened after the procedure. The level of sensorium worsened from excessively drowsy state to unconsciousness in seven patients. Three patients developed hemiparesis, 4 developed paresis of extra-ocular muscles and altered pupillary reflexes, and 1 developed incontinence of urine and persistent vomiting. Alteration in the delicately balanced intracranial pressure and movements in the tumour and vital adjacent brain areas could be the probable cause of the worsening in the neurological state in these 8 patients. On the basis of these observations and on review of literature, it is postulated that the ventricular dilatation following an obstruction in the path of the cerebrospinal fluid flow by a tumour could be a natural defense phenomenon of the brain.

  10. Classification system for reporting events involving human malfunctions

    The report describes a set of categories for reporting industrial incidents and events involving human malfunction. The classification system aims at ensuring information adequate for improvement of human work situations and man-machine interface systems and for attempts to quantify ''human error'' rates. The classification system has a multifacetted non-hierarchial structure and its compatibility with Ispra's ERDS classification is described. The collection of the information in general and for quantification purposes are discussed. 24 categories, 12 of which being human factors oriented, are listed with their respective subcategories, and comments are given. Underlying models of human data processes and their typical malfunctions and of a human decision sequence are described. (author)

  11. Echocardiographic analysis of a malfunctioning Davila-Sierra mitral valve

    Tri, Terry B.; Gregoratos, Gabriel

    1981-01-01

    Although the Davila-Sierra mitral valve prosthesis was removed from the market nearly a decade ago, a number of patients still have this valve in place. We recently studied the echocardiographic features of a malfunctioning Davila-Sierra mitral valve prosthesis. Abnormalities that suggested improper functioning of the prosthesis included a markedly delayed poppet opening and an early diastolic hump believed to represent motion of the mitral annulus. Previously described echocardiographic indi...

  12. Evaluation of Intrapulmonary Shunt Alterations at Different Oxygen Concentrations and Oxygenation Parameters

    Zerrin Demirtürk

    2015-06-01

    Full Text Available Aim: The aim of the current study was to evaluate the relationship of intrapulmonary shunt with FiO2 alterations in patients treated with mechanical ventilation in intensive care unit for extrapulmonary disorders. Also, we aimed to assess the role of correlation between shunt ratio and PaO2/FiO2, PaO2/PAO2, P(A-a O2 values in determining the treatment strategies. Methods: Twenty patients between ages of 19 and 75 years, requiring mechanical ventilation were enrolled into the study. We excluded two patients due to congestive heart failure and two patients due to acute respiratory distress syndrome (ARDS. Shunt fraction, P(A-aO2, PaO2/FiO2, PaO2/PAO2 values were calculated at each FiO2 level for each patient. Results: The lowest median shunt value was measured at FiO2: 0.3 There was a significant correlation between shunt values at FiO2 0.5 and 0.7 (r=0.850. The highest mean value of P(A-aO2 was measured at FiO2: 1 (382.91±106.46, and the lowest value of P(A-aO2 was measured at FiO2: 0.21 (38.64±16.97. PaO2/FiO2 and PaO2/PAO2 ratios measured at FiO2: 0.3 and 0.5 were found to be statistically significant. Conclusion: In this study, we have shown increased shunt fraction at FiO2: 1 level. Different oxygenation indices and shunt measurements give us important and useful knowledge about the patients’ current condition. (The Medical Bulletin of Haseki 2015; 53:124-9

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

    Jonathan Roth

    2015-01-01

    Conclusions: 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.

  14. Arne Torkildsen and the ventriculocisternal shunt: the first clinically successful shunt for hydrocephalus.

    Eide, Per Kristian; Lundar, Tryggve

    2016-05-01

    Arne Torkildsen was a pioneering Norwegian neurosurgeon who introduced the ventriculocisternal shunt, the first clinically successful shunt for CSF diversion in hydrocephalus. The procedure, usually referred to as ventriculocisternostomy (VCS), Torkildsen's operation, orTorkildsen's shunt, became internationally recognized as an efficient operation for the treatment of noncommunicating hydrocephalus. The operation gained widespread use in the 1940s and 1950s before the introduction of extracranial shunts. In this paper, the authors look more closely at Torkildsen's development of the VCS and examine how this surgical approach differed from other procedures for treating hydrocephalus before World War II. Long-term results of the VCS are presented. PMID:26339852

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

    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%).

  16. Severe respiratory failure following ventriculopleural shunt

    Shahzad Alam

    2015-01-01

    Full Text Available Cerebrospinal fluid (CSF diversion procedure has been used for long to treat hydrocephalus in children. The principle of shunting is to establish a communication between the CSF and a drainage cavity (peritoneum, right atrium, and pleura. Ventriculoperitoneal shunt is used most commonly, followed secondly by ventriculopleural shunt (VPLS. Hydrothorax due to excessive CSF accumulation is a rare complication following both the type of shunts and is more frequently seen with VPLS. We report a case of a 6-year-old female child presenting with massive CSF hydrothorax with respiratory failure following VPLS. The aim of the article is to highlight early recognition of this rare and life-threatening condition, which could easily be missed if proper history is not available.

  17. Syringosubarachnoid shunting using a myringotomy tube

    Leschke, Jack M.; Mumert, Michael L.; Kurpad, Shekar N.

    2016-01-01

    Background: Syringomyelia results from obstruction of cerebrospinal fluid (CSF) flow due to a multitude of causes. Often symptoms of pain, weakness, and sensory disturbance are progressive and require surgical treatment. We present here a rare technique for syringosubarachnoid shunting. Case Description: We present the case of a 38-year-old male who suffered a traumatic cervical spinal cord injury due to a motor vehicle accident. With progressive pain and motor decline, a magnetic resonance imaging was obtained and showed a new syrinx extending cervical multiple segments. A unique surgical procedure using a myringotomy tube to shunt CSF into the subarachnoid space was employed in this case. The patient's examination stabilized postoperatively, and at 2 months and 6 months follow-up visits, his strength and sensation continued to improve. Conclusion: We used a myringotomy tube for syringosubarachnoid shunting for the surgical management of a posttraumatic syrinx with good results. This technique minimizes suturing and may minimize shunt-related complications. PMID:26862456

  18. Mesoatrial shunt in Budd-Chiari syndrome

    Mirković Darko

    2009-01-01

    Full Text Available Background. Budd-Chiari syndrome (BCS represents partial or total occlusion of the hepatic veins with or without simultaneous obstruction of vena cava inferior (VCI. The symptoms of BCS are abdominal pain, hepatomegaly, ascites, varices of the abdominal wall, sometimes bleeding from the upper part of gastointestinal tract (GIT, lower limbs swelling and jaundice. Primary BSC is a relatively rare condition occurring in one per 100 000 of the population worldwide. Case report. A male patient, 25-year-old, facing tooth postextraction complications, was presented with acute BCS. On admission, physical examination revealed pale-grayish complexion, more pronounced veins over the thorax and abdomen, ascites, enlarged liver rising 8 cm below the right costal arch and having a minor pleural effusion by the right side. The patient was submitted to Doppler sonography and computed tomography (CT that verified the right leg deep veins thrombosis, as well as the presence of a thrombus in the intrahepatic portion of the VCI. Multislice computed tomography (MSCT showed occlusion of hepatic veins (Budd-Chiari syndrome and thrombosis of the VCI in the retrohepatic part 6 cm long. Also, increased values of transaminases and gamma GT and reduced values of albumines and serum ferrum were registered. Molecular examination revealed Factor V Leiden mutation - heterozygote. After preoperative preparations a mesocaval shunt was made using Gore- Tex ring graft of 12 mm. Intraoperatively, the blue enlarged liver was found with almost black zones of tense capsule. After a graft making, liver congestion decreased followed by the change of colour and volume. Within postoperative course metabolic and synthetic liver functions were obvious. Conclusion. In patients with BCS medicamentous treatment does not yield adequate results, but even causes worsening of general condition. Surgical therapy in the presented patient was performed timely regarding the stage of the disease due to

  19. Congenital portosystemic shunts with and without gastrointestinal bleeding - case series

    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.)

  20. Temporary intravascular shunts for peripheral vascular trauma.

    Husain A

    1992-04-01

    Full Text Available Polyvinylchloride (PVC disposable endotracheal suction catheters were successfully used as temporary intravascular shunts in 5 patients of popliteal artery trauma. These simple shunts should be used routinely in such conditions to immediately re-establish blood supply to the ischaemic limb particularly in patients of polytrauma where systemic anticoagulation is contraindicated. This avoids the inherent delay prior to vascular repair and reduces the incidence of irreversible ischemia.

  1. Cell shunt resistance and photovoltaic module performance

    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.

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

    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.

  3. Malfunction analysis of OPGW of stainless steel-unit structure

    李星梅; 张素芳; 王旭锋; 乞建勋

    2008-01-01

    Composite fiber optic overhead ground wire (OPGW) is increasingly applied in China’s overhead transmission lines. The stainless steel structure is adopted by most OPGWs as it is very small and easy to match the existing ground wire. The malfunction of OPGW in Beijing-Shanghai Optical Communication Project was analyzed through the chemical composition method and spectrum semi-quantitative method. The analysis indicates that the cable fault was due to the failure of seepage and irregular holes in the steel pipe of the optical unit. The rain water and the watery air entered into the optical units, and the water in turn became ice when temperature dropped. The occurrence of ice led to the acceleration of attenuation of the fiber. The results show that the rupture of stainless steel tube is mainly due to the instability of welding technique. The malfunction of OPGW is due to the local defects of welding seam because of local stress concentration in the manufacturing process.

  4. Simulation of Malfunctions for the ISS Double-Gimbal Control Moment Gyroscope

    Inampudi, Ravi; Gordeuk, John

    2016-01-01

    This paper presents a simplified approach to simulation of malfunctions of the Control Moment Gyroscope (CMG) on board the International Space Station (ISS). These malfunctions will be used as part of flight training of CMG failure scenarios in the guidance navigation control (GNC) subsystem of the Training Systems for 21st Century (TS21) simulator. The CMG malfunctions are grouped under mechanical, thermal and electrical categories. A malfunction can be as simple as one which only affects the telemetry or a complex one that changes the state and behavior of the CMG model. In both cases, the ISS GNC flight software will read the telemetry and respond accordingly. The user executes these malfunctions by supplying conditional data which modify internal model states and then elicit a response as seen on the user displays. Ground operators and crew on board the ISS use CMG malfunction procedures to better understand and respond to anomalies observed within the CMG subsystem.

  5. Neurogenic pulmonary edema due to ventriculo-atrial shunt dysfunction: a case report

    Ana Sofia Cruz; Sónia Menezes; Maria Silva

    2016-01-01

    ABSTRACT BACKGROUND AND OBJECTIVES: Pulmonary edema is caused by the accumulation of fluid within the air spaces and the interstitium of the lung. Neurogenic pulmonary edema is a clinical syndrome characterized by the acute onset of pulmonary edema following a significant central nervous system insult. It may be a less-recognized consequence of raised intracranial pressure due to obstructive hydrocephalus by blocked ventricular shunts. It usually appears within minutes to hours after the in...

  6. Coupling slots without shunt impedance drop

    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)

  7. A canine model of multiple portosystemic shunting.

    Howe, L M; Boothe, H W; Miller, M W; Boothe, D M

    2000-01-01

    The objective of this study was to develop and describe an experimental canine model of multiple acquired portosystemic shunts (PSS) similar in nature to spontaneously occurring PSS. Sixteen dogs were used and were divided into a control (n = 6) and a diseased group (n = 10). Dogs of the diseased group were administered dimethylnitrosamine (2 mg/kg of body weight, po) twice weekly, and clinicopathologic, ultrasonographic, and hepatic scintigraphic findings were recorded during the development of hepatic disease and PSS. Surgery was then performed to permit visual verification of multiple shunts, catheter placement for portography examination, and biopsy of the liver. All diseased dogs developed severe hepatic disease and multiple PSS as documented visually at surgery and on portography. Based on this study, dimethylnitrosamine-induced portosystemic shunting appears to be an appropriate model for spontaneously occurring multiple PSS secondary to portal hypertension. PMID:10741951

  8. Balanced calibration of resonant shunt circuits for piezoelectric vibration control

    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...

  9. Two unusual complications of ventriculoperitoneal shunts in the same infant

    Ventriculoperitoneal shunts have been associated with many different complications. We describe two rare complications in a 10-month-old girl. To the best of our knowledge, protrusion of ventriculoperitoneal shunt through the knee has not been reported before. (orig.)

  10. Right-to-left shunt with hypoxemia in pulmonary hypertension

    2009-01-01

    Background: Hypoxemia is common in pulmonary hypertension (PH) and may be partly related to ventilation/perfusion mismatch, low diffusion capacity, low cardiac output, and/or right-to-left (RL) shunting. Methods: To determine whether true RL shunting causing hypoxemia is caused by intracardiac shunting, as classically considered, a retrospective single center study was conducted in consecutive patients with precapillary PH, with hypoxemia at rest (PaO(2) < 10 kPa), shunt fraction (Qs/Qt) grea...

  11. Internal carotid artery rupture caused by carotid shunt insertion

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

    2015-01-01

    Introduction: 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. Presentation of case: A 78-year-old woman underwent CEA combined with coronary artery bypass grafting (CABG). At the time of shunt insertion an arteria...

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

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

    2014-01-01

    inconclusive multidisciplinary investigations, the patient progressed into end-stage renal disease before an echocardiogram revealed a vegetative plaque on the tendinous chords of the tricuspid valve. CSF cultures were grown from the shunt valve, confirming bacterial growth of Propionibacterium acnes suspected...

  13. Round worm migration along ventriculoperitoneal shunt tract: a rare complication.

    Agarwal P

    2000-01-01

    Full Text Available Though a ventriculoperitoneal shunt has been associated with myriads of unusual complications, so has been that with roundworms. A case of a three-year-old boy is presented who had an unusual complication of roundworm migration along the shunt tract that presented as shunt tract infection.

  14. Recurrent Breast Cancer in a Patient with a Ventriculoperitoneal Shunt

    Libby R. Copeland-Halperin

    2015-01-01

    Full Text Available We report a case of a patient with recurrent infiltrating ductal carcinoma of the breast encasing a ventriculoperitoneal shunt. We also review the current literature regarding reports of breast malignancy around a ventriculoperitoneal shunt, as well as the potential relevance of such shunts to the preoperative evaluation and management of patients with breast cancer.

  15. 21 CFR 876.5955 - Peritoneo-venous shunt.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Peritoneo-venous shunt. 876.5955 Section 876.5955...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5955 Peritoneo-venous shunt. (a) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a...

  16. 21 CFR 882.4545 - Shunt system implantation instrument.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shunt system implantation instrument. 882.4545... implantation instrument. (a) Identification. A shunt system implantation instrument is an instrument used in the implantation of cerebrospinal fluid shunts, and includes tunneling instruments for passing...

  17. 49 CFR 236.104 - Shunt fouling circuit.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunt fouling circuit. 236.104 Section 236.104 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.104 Shunt fouling circuit. Shunt fouling...

  18. Classification system for reporting events involving human malfunctions

    The report describes a set of categories for reporting industrial incidents and events involving human malfunction. The classification system aims at ensuring information adequate for improvement of human work situations and man-machine interface systems and for attempts to quantify ''human error'' rates. The classification system has a multifacetted non-hierarchical structure and its compatibility with Ispra's ERDS classification is described. The collection of the information in general and for quantification purposes are discussed. 24 categories, 12 of which being human factors-oriented, are listed with their respective subcategories, and comments are given. Underlying models of human data process and their typical malfuntions and of a human decision sequence are described. The work reported is a joint contribution to the CSNI Group of Experts on Human Error Data and Assessment

  19. Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question

    Klein, Michael R.; Kiefer, Todd L.; Velazquez, Eric J.

    2016-01-01

    Platypnea-orthodeoxia syndrome is a rare disease defined by dyspnea and deoxygenation, induced by an upright position, and relieved by recumbency. Causes include shunting through a patent foramen ovale and pulmonary arteriovenous malformations.

  20. Fabrication of capacitively-shunted superconducting qubits

    Yoder, Jonilyn L.; Gudmundsen, Theodore J.; Bolkhovsky, Vladimir; Welander, Paul B.; Gustavsson, Simon; Hover, David; Kerman, Andrew J.; Sears, Adam P.; Oliver, William D.

    2014-03-01

    Improvements in superconducting qubit coherence times and reproducibility have been demonstrated using capacitive shunting. In this study, we present methods for the preparation of both capacitively-shunted charge qubits (transmons) and capacitively-shunted flux qubits. Hybrid fabrication techniques were employed to combine high-quality-factor aluminum capacitive shunts with shadow-evaporated Josephson junctions, and the Josephson junctions were prepared using suspended-bridge germanium masks. We also will describe process testing results that were acquired to assess wafer-to-wafer reproducibility of our fabrication protocols. This research was funded in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA); and by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract number FA8721-05-C-0002. All statements of fact, opinion or conclusions contained herein are those of the authors and should not be construed as representing the official views or policies of IARPA, the ODNI, or the U.S. Government.

  1. Train shunting at a workshop area

    Jacobsen, Per Munk; Pisinger, David

    2011-01-01

    We consider the problem of planning the shunting of train units at a railway workshop area. Before and after the maintenance check, a train unit is parked at a depository track. The problem is to schedule the trains to workshops and depot tracks in order to complete the repairs as soon as possible...

  2. Muzzle shunt augmentation of conventional railguns

    Parker, J.V.

    1990-01-01

    Augmentation is a well-known technique for reducing the armature current and hence the armature power dissipation in a plasma armature railgun. In spite of the advantages, no large augmented railguns have been built, primarily due to the mechanical and electrical complexity introduce by the extra conductors required. It is possible to achieve some of the benefits of augmentation in conventional railgun by diverting a fraction {phi} of the input current through a shunt path at the muzzle of the railgun. In particular, the relation between force and armature current is the same as that obtained in an n-turn, series connected augmented railgun with n = 1/(1-{phi}). The price of this simplification is a reduction in electrical efficiency and some additional complexity in the external electrical system. Additions to the electrical system are required to establish the shunt current and to control its magnitude during projectile acceleration. The relationship between muzzle shunt augmentation and conventional series augmentation is developed and various techniques is developed and various techniques for establishing and controlling the shunt current are illustrated with a practical example. 5 refs., 8 figs., 2 tabs.

  3. Resting pulmonary haemodynamics and shunting: a comparison of sea-level inhabitants to high altitude Sherpas

    Foster, Glen E; Ainslie, Philip N; Stembridge, Mike; Day, Trevor A; Bakker, Akke; Lucas, Samuel J E; Lewis, Nia C S; MacLeod, David B; Lovering, Andrew T

    2014-01-01

    The incidence of blood flow through intracardiac shunt and intrapulmonary arteriovenous anastomoses (IPAVA) may differ between Sherpas permanently residing at high altitude (HA) and sea-level (SL) inhabitants as a result of evolutionary pressure to improve gas exchange and/or resting pulmonary haemodynamics. To test this hypothesis we compared sea-level inhabitants at SL (SL-SL; n = 17), during acute isocapnic hypoxia (SL-HX; n = 7) and following 3 weeks at 5050 m (SL-HA; n = 8 non-PFO subjects) to Sherpas at 5050 m (n = 14). , heart rate, pulmonary artery systolic pressure (PASP) and cardiac index (Qi) were measured during 5 min of room air breathing at SL and HA, during 20 min of isocapnic hypoxia (SL-HX; = 47 mmHg) and during 5 min of hyperoxia ( = 1.0; Sherpas only). Intracardiac shunt and IPAVA blood flow was evaluated by agitated saline contrast echocardiography. Although PASP was similar between groups at HA (Sherpas: 30.0 ± 6.0 mmHg; SL-HA: 32.7 ± 4.2 mmHg; P = 0.27), it was greater than SL-SL (19.4 ± 2.1 mmHg; P < 0.001). The proportion of subjects with intracardiac shunt was similar between groups (SL-SL: 41%; Sherpas: 50%). In the remaining subjects, IPAVA blood flow was found in 100% of subjects during acute isocapnic hypoxia at SL, but in only 4 of 7 Sherpas and 1 of 8 SL-HA subjects at rest. In conclusion, differences in resting pulmonary vascular regulation, intracardiac shunt and IPAVA blood flow do not appear to account for any adaptation to HA in Sherpas. Despite elevated pulmonary pressures and profound hypoxaemia, IPAVA blood flow in all subjects at HA was lower than expected compared to acute normobaric hypoxia. PMID:24396057

  4. 40 CFR 60.2918 - What happens during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Performance Testing...

  5. 40 CFR 60.2120 - What happens during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... 1, 2001 Emission Limitations and Operating Limits § 60.2120 What happens during periods of startup... during CISWI unit startups, shutdowns, or malfunctions. (b) Each malfunction must last no longer than...

  6. 40 CFR 63.2852 - What is a startup, shutdown, and malfunction plan?

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What is a startup, shutdown, and... Production Compliance Requirements § 63.2852 What is a startup, shutdown, and malfunction plan? You must...)(2) malfunction period, or the § 63.2850(c)(2) or (d)(2) initial startup period. The SSM plan...

  7. 40 CFR 60.2685 - What happens during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during CISWI unit startups, shutdowns, or malfunctions. (b)...

  8. 40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model...

  9. Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question.

    Klein, Michael R; Kiefer, Todd L; Velazquez, Eric J

    2016-06-01

    Platypnea-orthodeoxia syndrome is a rare disease defined by dyspnea and deoxygenation, induced by an upright position, and relieved by recumbency. Causes include shunting through a patent foramen ovale and pulmonary arteriovenous malformations. A 79-year-old woman experienced 2 syncopal episodes at rest and presented at another hospital. In the emergency department, she was hypoxic, needing 6 L/min of oxygen. Her chest radiograph showed nothing unusual. Transthoracic echocardiograms with saline microcavitation evaluation were mildly positive early after agitated-saline administration, suggesting intracardiac shunting. She was then transferred to our center. Right-sided heart catheterization revealed no oximetric evidence of intracardiac shunting while the patient was supine and had a low right atrial pressure. However, her oxygen saturation dropped to 78% when she sat up. Repeat transthoracic echocardiography while sitting revealed a dramatically positive early saline microcavitation-uptake into the left side of the heart. Transesophageal echocardiograms showed a patent foramen ovale, with right-to-left shunting highly dependent upon body position. The patient underwent successful percutaneous patent foramen ovale closure, and her oxygen supplementation was suspended. In patients with unexplained or transient hypoxemia in which a cardiac cause is suspected, it is important to evaluate shunting in both the recumbent and upright positions. In this syndrome, elevated right atrial pressure is not necessary for significant right-to-left shunting. Percutaneous closure, if feasible, is first-line therapy in these patients. PMID:27303248

  10. Encefalopatía hepática secundaria a la existencia de un shunt portosistémico tratada satisfactoriamente mediante radiología intervencionista Hepatic encephalophaty secondary to porto-systemic shunt satisfactorily treated with interventionist radiology

    L. Crespo

    2007-11-01

    Full Text Available La encefalopatía hepática es un estado reversible de alteración en la función cognitiva, que puede ocurrir en pacientes con enfermedad hepática aguda o crónica o shunts porto-sistémicos, en el que puede aparecer cualquiera de los signos neurológicos o psiquiátricos conocidos. Las sustancias nitrogenadas procedentes de la digestión intestinal alcanzan el cerebro sin la depuración que supone su paso por el hígado, debido a las derivaciones porto-sistémicas, y dan lugar a los signos característicos de la encefalopatía hepática. A continuación presentamos dos casos clínicos de pacientes con shunt porto-sistémicos, diagnosticados de encefalopatía hepática crónica recurrente refractaria al tratamiento médico convencional, tratados satisfactoriamente con embolización de dicho shunt mediante técnicas de radiología intervencionista.Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques.

  11. Laparoscopy versus mini-laparotomy peritoneal catheter insertion of ventriculoperitoneal shunts: a systematic review and meta-analysis.

    He, Mingliang; Ouyang, Leping; Wang, Shengwen; Zheng, Meiguang; Liu, Anmin

    2016-09-01

    OBJECTIVE Ventriculoperitoneal (VP) shunt treatment is the main treatment method for hydrocephalus. The traditional operative approach for peritoneal catheter insertion is mini-laparotomy. In recent years, laparoscopy-assisted insertion has become increasingly popular. It seems likely that use of an endoscope could lower the incidence of shunt malfunction. However, there is no consensus about the benefits of laparoscopy-assisted peritoneal catheter insertion. METHODS A systematic search was performed using the PubMed, Embase, ScienceDirect, and Cochrane Library databases. A manual search for reference lists was conducted. The protocol was prepared according to the interventional systematic reviews of the Cochrane Handbook, and the article was written on the basis of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. RESULTS Eleven observational trials and 2 randomized controlled trials were included. Seven operation-related outcome measures were analyzed, and 3 of these showed no difference between operative techniques. The results of the meta-analysis are as follows: in the laparoscopy group, the rate of distal shunt failure was lower (OR 0.41, 95% CI 0.25-0.67; p = 0.0003), the absolute effect is 7.11% for distal shunt failure, the number needed to treat is 14 (95% CI 8-23), operative time was shorter (mean difference [MD], -12.84; 95% CI -20.68 to -5.00; p = 0.001), and blood loss was less (MD -9.93, 95% CI -17.56 to -2.31; p = 0.01). In addition, a borderline statistically significant difference tending to laparoscopic technique was observed in terms of hospital stay (MD -1.77, 95% CI -3.67 to 0.13; p = 0.07). CONCLUSIONS To some extent, a laparoscopic insertion technique could yield a better prognosis, mainly because it is associated with a lower distal failure rate and shorter operative time, which would be clinically relevant. PMID:27581319

  12. Defective Homocysteine Metabolism: Potential Implications for Skeletal Muscle Malfunction

    Suresh C. Tyagi

    2013-07-01

    Full Text Available Hyperhomocysteinemia (HHcy is a systemic medical condition and has been attributed to multi-organ pathologies. Genetic, nutritional, hormonal, age and gender differences are involved in abnormal homocysteine (Hcy metabolism that produces HHcy. Homocysteine is an intermediate for many key processes such as cellular methylation and cellular antioxidant potential and imbalances in Hcy production and/or catabolism impacts gene expression and cell signaling including GPCR signaling. Furthermore, HHcy might damage the vagus nerve and superior cervical ganglion and affects various GPCR functions; therefore it can impair both the parasympathetic and sympathetic regulation in the blood vessels of skeletal muscle and affect long-term muscle function. Understanding cellular targets of Hcy during HHcy in different contexts and its role either as a primary risk factor or as an aggravator of certain disease conditions would provide better interventions. In this review we have provided recent Hcy mediated mechanistic insights into different diseases and presented potential implications in the context of reduced muscle function and integrity. Overall, the impact of HHcy in various skeletal muscle malfunctions is underappreciated; future studies in this area will provide deeper insights and improve our understanding of the association between HHcy and diminished physical function.

  13. Circadian malfunctions in depression - neurobiological and psychosocial approaches.

    Nechita, Florina; Pîrlog, Mihail Cristian; ChiriŢă, Anca Livia

    2015-01-01

    Depression leads to disturbances in physiological rhythms, which result in disturbances in circadian sleep-wake cycles, hormonal secretion patterns and fluctuations in mood, all of which can be objectively measured. These disturbances, which are associated with depression, can be also used to define depression. Beyond these "transversal" time-related symptoms, there are the "longitudinal" time-related symptoms, since depression evolves over a long period of time, with a profound impact on a person's life and is often associated with long-term psychosocial consequences (Mendlewicz, 2010). The circadian rhythm reflects an approximate 24-hour cycle in the biochemical, physiological and behavioral processes of living entities, which crucially influences human well-being and health. Increasing evidence from clinical and neurobiological research suggests that disrupted temporal organization impairs behavior, cognition, mood, sleep and social activity and may be implicated in mental disorders. It has been proposed that circadian malfunction is a major core feature of mood disorders, depression in particular. In depressed patients, circadian rhythms and homeostatic processes are disrupted, thereby affecting mood, sleep, activity and a variety of biological functions such as hormone secretion and body temperature (Hajak & Landgrebe, 2010). Sleep difficulties are among the most current symptoms in depressed patients. Insomnia is often the reason why depressed patients seek help and relief of sleep disturbance may encourage compliance with antidepressant treatment. Apart from the discomfort that sleep problems produce, they may lead to exhaustion, poor functioning and they are associated with an increase in suicide risk (Wilson et al., 2013). PMID:26662127

  14. Dc SQUIDs with asymmetric shunt resistors

    We have investigated asymmetrically shunted Nb/Al-AlOx/Nb dc SQUIDs. Simulations based on the coupled Langevin equations predict that the optimum energy resolution ε, and thus also the noise performance of such an asymmetric SQUID, can be 3-4 times better than that of its symmetric counterpart. While keeping the total resistance R identical to a comparable symmetric SQUID with R-1 = R1-1 + R2-1, we shunted only one of the two Josephson junctions with R = R1,2/2. Both types of SQUIDs were characterized with respect to their transport and noise properties at temperature T = 4.2 K, and we compared the experimental results with numerical simulations. Experiments yielded ε ∼ 32 ℎ for an asymmetric SQUID with an inductance L = 22 pH, whereas a comparable symmetric device achieved ε = 110 ℎ.

  15. 40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction...

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

    Owen, Joshua M; Gaba, Ron Charles

    2016-01-01

    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.

  17. An expert system for sensor data validation and malfunction detection

    Nuclear power plant operation and monitoring in general is a complex task which requires a large number of sensors, alarms and displays. At any instant in time, the operator is required to make a judgment about the state of the plant and to react accordingly. During abnormal situations, operators are further burdened with time constraints. The possibility of an undetected faulty instrumentation line, adds to the complexity of operators' reasoning tasks. Failure of human operators to cope with the conceptual complexity of abnormal situations often leads to more serious malfunctions and further damages to plant (TMI-2 as an example). During these abnormalities, operators rely on the information provided by the plant sensors and associated alarms. Their usefulness however, is quickly diminished by their large number and the extremely difficult task of interpreting and comprehending the information provided by them. The need for an aid to assist the operator in interpreting the available data and diagnosis of problems is obvious. Recent work at the Ohio State University Laboratory of Artificial Intelligence Research (LAIR) and the nuclear engineering program has concentrated on the problem of diagnostic expert systems performance and their applicability to the nuclear power plant domain. There has also been concern about the diagnostic expert systems performance when using potentially invalid sensor data. Because of this research, an expert system has been developed that can perform diagnostic problem solving despite the existence of some conflicting data in the domain. This work has resulted in enhancement of a programming tool, that allows domain experts to create a diagnostic system that will be to some degree, tolerant of bad data while performing diagnosis. This expert system is described here

  18. Effect of peritoneo-venous shunt on portal pressure.

    Samanta, A K; Leevy, C. M.

    1989-01-01

    The cause of variceal bleed after a peritoneo-venous shunt is not known. Portal haemodynamic consequences of a peritoneo-venous shunt are poorly understood. The most critical period after a peritoneo-venous shunt is the early postoperative period when rapid mobilisation of peritoneal fluid occurs. Serial changes in the portal pressure during the early postoperative period have not been recorded. In the present study preoperative wedge hepatic vein (WHV), right atrial (RA) and pulmonary capill...

  19. Medulloblastoma: seeding of VP shunt tract and peritoneum

    David Pettersson; Schmitz, Kelli R.; Pollock, Jeffrey M.; Katharine L. Hopkins

    2012-01-01

    We report on a 5-year-old boy with seeding of the peritoneum and a ventriculoperitoneal shunt tract by anaplastic medulloblastoma. The role of ventriculoperitoneal shunting in the spread of primary central nervous system tumors has been controversial. In the case reported here, the unique distribution of tumor implants on ultrasound and multiplanar computed tomography gives further credence to the argument that ventriculoperitoneal shunting is a pathway for extraneural metastases of primary c...

  20. SUBGALEAL MIGRATION OF THE DISTAL CATHETER OF A VENTRICULOPERITONEAL SHUNT

    Vinayak

    2015-08-01

    Full Text Available INTRODUCTION : Migration is a rare complication of venticuloperitoneal shunts and is thought to be associated with the "memory" of the plastic tubing and the windlass effect of neck flexion and extension. CASE PRESENTATION: A 11 months infant was bought to the hospital presenting with complaints of vomitin g, fever, drowsiness and progressive swelling on previous operated site at right occipital region with history of previous ventriculoperitoneal shunt surgery. CONCLUSIONS: Migration of inserted shunt system in subgaleal space is a rarity

  1. Radiological evaluation of coronary artery-cardiac chamber shunt

    Matsunaga, Naofumi

    1987-09-01

    Coronary artery-cardiac chamber shunts were observed in 84 cases out of consecutive 1,126 cases in which coronary angiography was performed. This ''coronary artery-cardiac chamber shunt'' has no draining vein and contrast material directly escapes into the cardiac chamber, which is different from the so-called ''coronary arterio-venous fistula''. The angiographic features of coronary artery-cardiac chamber shunt were classified into three types; Type I (57 cases): Endocardium is diffusely opacified on distole, and contrast material escapes into the cardiac chamber on systole. Type II (13 cases): A small localized direct coronary artery-cardiac chamber shunt. Type III (20 cases): Contrast material escapes into the cardiac chamber in the area of mural thrombus of the left atrium or left ventricle. It is speculated that type I shunt is due to persistent arterio-sinusoidal vessel, and type II shunt is due to persistent arterio-luminal vessel. Type I and II shunts were observed in hypertrophic cardiomyopathy with high incidence (42.4 %). In hypertrophic cardiomyopathy, the degree of shunts was not correlated with the degree of the ventricular wall thickening. These shunts were not also correlated with the presence or absence of myocardial squeezing. These facts suggest that the shunts may be due to the abnormality of the microcirculation of the myocardium. Type III shunt was observed in the mural thrombus in the left ventricle (7 cases), left atrial thrombus (12 cases) and verruca of the mitral valve (1 case). Angiographic features of these shunts are described, and their pathophysiological significance is discussed.

  2. 40 CFR 1045.110 - How must my engines diagnose malfunctions?

    2010-07-01

    ... color except red. Visible malfunction indicators must display “Check Engine,” “Service Engine Soon,” or... engine operation. (d) Store trouble codes in computer memory. Record and store in computer memory...

  3. Semi-shunt field emission in electronic devices

    Karpov, V. G.; Shvydka, Diana

    2014-08-01

    We introduce a concept of semi-shunts representing needle shaped metallic protrusions shorter than the distance between a device electrodes. Due to the lightening rod type of field enhancement, they induce strong electron emission. We consider the corresponding signature effects in photovoltaic applications; they are: low open circuit voltages and exponentially strong random device leakiness. Comparing the proposed theory with our data for CdTe based solar cells, we conclude that stress can stimulate semi-shunts' growth making them shunting failure precursors. In the meantime, controllable semi-shunts can play a positive role mitigating the back field effects in photovoltaics.

  4. Semi-shunt field emission in electronic devices

    Karpov, V. G., E-mail: victor.karpov@utoledo.edu [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Shvydka, Diana, E-mail: diana.shvydka@utoledo.edu [Department of Radiation Oncology, University of Toledo, Toledo, Ohio 43606 (United States)

    2014-08-04

    We introduce a concept of semi-shunts representing needle shaped metallic protrusions shorter than the distance between a device electrodes. Due to the lightening rod type of field enhancement, they induce strong electron emission. We consider the corresponding signature effects in photovoltaic applications; they are: low open circuit voltages and exponentially strong random device leakiness. Comparing the proposed theory with our data for CdTe based solar cells, we conclude that stress can stimulate semi-shunts' growth making them shunting failure precursors. In the meantime, controllable semi-shunts can play a positive role mitigating the back field effects in photovoltaics.

  5. A compact, coaxial shunt current diagnostic for X pinches

    Wang, Liangping; Zhang, Jinhai; Li, Mo; Zhang, Xinjun; Zhao, Chen; Zhang, Shaoguo

    2015-08-01

    A compact coaxial shunt was applied in X-pinches experiments on Qiangguang pulsed power generator. The coaxial shunt was designed to have a compact construction for smaller inductance and more, for conveniently assembling upon the X pinch load structure. The coaxial shunt is also a cheap current probe and was easily built by research groups. The shunt can monitor a 100 kA high current with a 100 ns rise time. The calibration results showed that the probe used in the experiments has a resistance of 3.2 mΩ with an uncertainty of 3%, and its response time to the step signal is less than 7 ns.

  6. Superconducting fault current-limiter with variable shunt impedance

    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.

  7. Unidirectional valve malfunction by the breakage or malposition of disc - two cases report -

    Lee, Chol; Lee, Kyu Chang; Kim, Hye Young; Kim, Mi Na; Choi, Eun Kyung; Kim, Ji-Sub; Lee, Won Sang; Lee, Myeong Jong; Kim, Hyung Tae

    2013-01-01

    Malfunction of the unidirectional valve in a breathing circuit system may cause hypercapnia from the rebreathing of expired gas, ventilation failure, and barotrauma. Capnography is a useful method for monitoring the integrity of the unidirectional valve. We experienced two cases of malfunction of a unidirectional valve which caused leakage and reverse flow, diagnosed early as a change of the capnographic waveform. One case was caused by expiratory unidirectional valve breakage. The other was ...

  8. On the malfunction of disk-type induction relay under seismic condition

    This paper deals with the malfunction of disk-type induction relay. Equations of motion for rotational movement of induction relay was formulated and the dynamic behavior was simulated under various kind of exciting conditions. Experimental verification was also performed using two dimensional shaker table for some actual relays. Sufficient agreement was recognized between experimental and analytical results and consequently the most critical reason to cause the malfunction was pointed out. (orig.)

  9. Long-Term Neuropsychological Sequelae in HIV-Seronegative Cryptococcal Meningoencephalitis Patients with and without Ventriculoperitoneal Shunts: A Cine MRI Study

    Meng-Hsiang Chen

    2015-01-01

    Full Text Available Background. Hydrocephalus in cryptococcal meningoencephalitis is most commonly managed with a ventriculoperitoneal shunt. This study applied cine magnetic resonance imaging (MRI to evaluate initial disease severity on long-term cerebrospinal fluid (CSF flow dynamics and associated neuropsychological sequelae in cryptococcal meningoencephalitis patients with and without ventriculoperitoneal shunts. Methods. Eighteen human immunodeficiency virus-seronegative cryptococcal meningoencephalitis patients (10 with shunts versus 8 without shunts were compared with 32 age- and sex-matched healthy volunteers. All subjects underwent complete neurologic examination and neuropsychological testing. Cine MRI was conducted to evaluate CSF flow parameters. Initial CSF laboratory analysis and imaging findings were correlated with present CSF flow parameters and neuropsychological scores. Results. Patients without shunts had higher average flow than controls, suggesting chronic hydrocephalus. Initial Evans ratios and CSF glucose levels were associated with CSF peak velocity and flow. Worsening CSF flow parameters correlated with decreased neuropsychological performance. Conclusions. CSF flow parameter differences between the cryptococcal meningoencephalitis patients both with and without ventriculoperitoneal shunts could be detected by cine MRI and correlated with acute stage disease severity and chronic stage neuropsychological results. Cine MRI is useful for assessing the chronic hydrocephalus that may lead to neuropsychological deficits in cryptococcal meningoencephalitis patients.

  10. Embolization of severe arterioportal shunts in the patients with hepatocellular carcinoma : safety and influence on patient survival

    Lee, Deok Hee; Yoon, Hyun Ki; Song, Ho Young; Kim, Gab Choul; Hwang, Jae Cheol; Sung, Kyu Bo [Asan Medical Center, Ulsan Univ. College of Medicine, Ulsan (Korea, Republic of)

    1999-12-01

    To evaluate the safety and the influence of embolization of severe arterioportal shunts, and the effect of the procedure on the survival rate of patients with hepatocellular carcinoma combined with portal vein tumor thrombosis. This study involved a total of 54 patients with hepatocellular carcinoma in whom hepatic arteriography revealed severe arterioportal shunt. From among this total, 34 patients (embolization group) underwent chemoinfusion after shunt embolization, while 19 (control group) underwent chemoinfusion only. The embolic materials included PVA particles and /or Gelfoam pieces. The frequency of postem-bolization symptoms (Chi-squared test) and changes in laboratory values (paired t-test) were compared between the two groups, and shunt improvement was also evaluated. Patient survival was tested using the Kaplan-Meier method. Fever and RUQ pain were more frequent in the embolization group (p<0.001). The complications of embolization included severe postembolization syndrome (n=1), acute hepatic failure (n=2), hepatic infarction (n=1), and sepsis (n=1). There were no significant changes in laboratory values. Among the 28 patients (24 of embolization group and four of control group) who underwent follow-up angiography, arterioportal shunt became less severe or disappeared in ten of the embolization group. For the embolization and control groups, the mean survival interval was 29.5{+-}5.4 weeks and 10.3{+-}3.1 weeks (p=0.0002), respectively. The best results were seen in the PVA particle group (p=0.01). The embolization of severe arterioportal shunts is relatively safe and increases patient survival rate.

  11. Embolization of severe arterioportal shunts in the patients with hepatocellular carcinoma : safety and influence on patient survival

    To evaluate the safety and the influence of embolization of severe arterioportal shunts, and the effect of the procedure on the survival rate of patients with hepatocellular carcinoma combined with portal vein tumor thrombosis. This study involved a total of 54 patients with hepatocellular carcinoma in whom hepatic arteriography revealed severe arterioportal shunt. From among this total, 34 patients (embolization group) underwent chemoinfusion after shunt embolization, while 19 (control group) underwent chemoinfusion only. The embolic materials included PVA particles and /or Gelfoam pieces. The frequency of postem-bolization symptoms (Chi-squared test) and changes in laboratory values (paired t-test) were compared between the two groups, and shunt improvement was also evaluated. Patient survival was tested using the Kaplan-Meier method. Fever and RUQ pain were more frequent in the embolization group (p<0.001). The complications of embolization included severe postembolization syndrome (n=1), acute hepatic failure (n=2), hepatic infarction (n=1), and sepsis (n=1). There were no significant changes in laboratory values. Among the 28 patients (24 of embolization group and four of control group) who underwent follow-up angiography, arterioportal shunt became less severe or disappeared in ten of the embolization group. For the embolization and control groups, the mean survival interval was 29.5±5.4 weeks and 10.3±3.1 weeks (p=0.0002), respectively. The best results were seen in the PVA particle group (p=0.01). The embolization of severe arterioportal shunts is relatively safe and increases patient survival rate

  12. Neurogenic pulmonary edema due to ventriculo-atrial shunt dysfunction: a case report

    Ana Sofia Cruz

    2016-04-01

    Full Text Available ABSTRACT BACKGROUND AND OBJECTIVES: Pulmonary edema is caused by the accumulation of fluid within the air spaces and the interstitium of the lung. Neurogenic pulmonary edema is a clinical syndrome characterized by the acute onset of pulmonary edema following a significant central nervous system insult. It may be a less-recognized consequence of raised intracranial pressure due to obstructive hydrocephalus by blocked ventricular shunts. It usually appears within minutes to hours after the injury and has a high mortality rate if not recognized and treated appropriately. CASE REPORT: We report a patient with acute obstructive hydrocephalus due to ventriculo-atrial shunt dysfunction, proposed to urgent surgery for placement of external ventricular drainage, who presented with neurogenic pulmonary edema preoperatively. She was anesthetized and supportive treatment was instituted. At the end of the procedure the patient showed no clinical signs of respiratory distress, as prompt reduction in intracranial pressure facilitated the regression of the pulmonary edema. CONCLUSIONS: This report addresses the importance of recognition of neurogenic pulmonary edema as a possible perioperative complication resulting from an increase in intracranial pressure. If not recognized and treated appropriately, neurogenic pulmonary edema can lead to acute cardiopulmonary failure with global hypoperfusion and hypoxia. Therefore, awareness of and knowledge about the occurrence, clinical presentation and treatment are essential.

  13. Memory and selective learning in children with spina bifida-myelomeningocele and shunted hydrocephalus: A preliminary study

    Vachha Behroze

    2005-11-01

    Full Text Available Abstract Background Selective learning is the ability to select items of relevance from among less important items. Limited evidence exists regarding the efficiency with which children with spina bifida-myelomeningocele and shunted hydrocephalus (SB/SH are able to learn information. This report describes initial data related to components of learning and metacognitive skills in children with SB/SH. Methods Twenty six children with SB/SH and 26 controls (age: 7 – 16 y with average intelligence, and monolingual English-speaking backgrounds participated in the study. Exclusion criteria for the SB/SH group were: prior history of shunt infection, history of seizure or shunt malfunction within the previous three months, prior diagnoses of attention disorders and/or clinical depression. Children were presented lists of words with equal exemplars each of two distinct semantic categories (e.g. fruits, animals, and told to make as high a score as possible by learning the words. The value of the words was designated by category membership (e.g. animals = low value; fruits = high value. The total number of words learned across three learning trials was used to determine memory span. Selective learning efficiency (SLE was computed as the efficiency with which items of greater value were selectively learned across three trials. Results Children with SB/SH did worse than controls on memory span (P Conclusion Success in school is often dependent on the ability to recall important facts selectively and ignore less important information. Children with SB/SH in our study had a poor memory span and were unable to monitor and report an efficient and workable metacognitive strategy required to remember a list of words. Preliminary findings may begin to explain our previous clinical and research findings wherein children with SB/SH often focus on extraneous details, but demonstrate difficulty remembering the main gist of a story/event.

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

    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

  15. Epidural hematoma after ventriculoperitoneal shunt surgery: report of two cases

    PEREIRA CARLOS UMBERTO

    1998-01-01

    Full Text Available Ventriculoperitoneal shunt operations represent the most used choice for treating hydrocephalus, although some related complications have been reported. Due to its rarity, potential dangers, and mortality rate, we present two cases of epidural hematoma following ventriculoperitoneal shunt, discussing its pathophysiology and prophylaxis.

  16. Evaluation of Blalock-Taussig shunts using magnetic resonance imaging

    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)

  17. Evaluation of Blalock-Taussig shunts using magnetic resonance imaging

    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.

  18. Flexural waves focusing through shunted piezoelectric patches

    Yi, K.; Collet, M.; Ichchou, M.; Li, L.

    2016-07-01

    In this paper, we designed and analyzed a piezo-lens to focus flexural waves in thin plates. The piezo-lens is comprised of a host plate and piezoelectric arrays bonded on the surfaces of the plate. The piezoelectric patches are shunted with negative capacitance circuits. The effective refractive indexes inside the piezo-lens are designed to fit a hyperbolic secant distribution by tuning the negative capacitance values. A homogenized model of a piezo-mechanical system is adopted in the designing process of the piezo-lens. The wave focusing effect is studied by the finite element method. Numerical results show that the piezo-lens can focus flexural waves by bending their trajectories, and is effective in a large frequency band. The piezo-lens has the ability to focus flexural waves at different locations by tuning the shunting negative capacitance values. The piezo-lens is shown to be effective for flexural waves generated by different types of sources.

  19. Self-expanding stents in transjugular intrahepatic portosystemic shunt: experience with nitinol Strecker stents.

    Rossi, P; Bezzi, M; Salvatori, F M; Broglia, L; Maccioni, F; Pizzi, G; Abbondanza, S; Bonomo, G

    1996-01-01

    The aim of our study was to evaluate the performance and efficacy of a new self-expanding stent (nitinol Strecker stent) in the transjugular intrahepatic portosystemic shunt (TIPS) procedure. We have successfully placed 64 nitinol Strecker stents in 48 patients. The average portosystemic gradient decreased from 22 to 11 mm Hg. Balloon dilatation was necessary in 12 of 35 angiographically controlled cases at 5 days (34%), because of incomplete stent expansion, small thrombi within the stent or obstruction. At 1-6 months stent malfunctions occurred in 8 of 23 patients who underwent control angiography (34%) and at 6-24 months in 6 of 7 patients (85%). Rebleeding occurred in 2 of 39 patients (follow-up > 1 month) (5%) and temporary crises of de novo encephalopathy were observed in 11 of 48 patients (23%). Refractory ascites completely resolved in 4 of 6 patients (66%) and improved in the remaining 2 cases. Compared with other self-expanding stents, nitinol Strecker stents seem to be equally effective in TIPS; no increase in complication rate was observed, either clinical or stent-related. PMID:8934143

  20. The influence of automation malfunctions and interface design on operator performance. The HCA-2001 experiment

    Skjerve, Ann Britt Miberg; Strand, Stine; Saarni, Ray; Skraaning, Gyrd Jr.

    2002-08-15

    This report presents the study plan and results of the Human Centred Automation 2001 experiment. The experiment was designed as a close follow-up of the HCA-2000 experiment, and the purpose was thus to examine how operators handle two types of automation malfunctions when working from interfaces that contain either explicit or implicit information about the automatic system. The experiment was carried out in the Nokia Research Simulator in HAMMLAB, and a total of 18 licensed operators from the Loviisa NPP participated. The experimental design was a Randomised Block Factorial-223 design, comprised by automation malfunction type with two manipulated levels, automation information (AIP) presentation type with two manipulated levels, and scenario period with three levels. The automation malfunction types were termed component malfunctions and strategy malfunctions, in which the first type referred to automation slips, i.e. failure in execution, and the latter type referred to automation mistakes, i.e. failure in planning. The AIP types were termed conventional AIP interface and experimental AIP interface, where the latter provided explicit verbal and graphical information about the automatic system. Some alterations were made with regard to both the scenario design and the provision of verbal feedback compared to the HCA-2000 experiment. The hypotheses were specified with reference to a SImple Model of Operator Activity (SIMOA), developed within the HCA-program and thoroughly accounted for in this report. SIMOA constitutes a cyclical model and refers to schema theory. The hypotheses stating that the operators would correctly handle component malfunctions faster than strategy malfunctions, and that workload would be lower, and situation awareness, trust in automation, and quality of cooperation would be higher when component rather than strategy malfunctions occurred, was not supported by the results. However, the hypotheses that operators would correctly handle

  1. The influence of automation malfunctions and interface design on operator performance. The HCA-2001 experiment

    This report presents the study plan and results of the Human Centred Automation 2001 experiment. The experiment was designed as a close follow-up of the HCA-2000 experiment, and the purpose was thus to examine how operators handle two types of automation malfunctions when working from interfaces that contain either explicit or implicit information about the automatic system. The experiment was carried out in the Nokia Research Simulator in HAMMLAB, and a total of 18 licensed operators from the Loviisa NPP participated. The experimental design was a Randomised Block Factorial-223 design, comprised by automation malfunction type with two manipulated levels, automation information (AIP) presentation type with two manipulated levels, and scenario period with three levels. The automation malfunction types were termed component malfunctions and strategy malfunctions, in which the first type referred to automation slips, i.e. failure in execution, and the latter type referred to automation mistakes, i.e. failure in planning. The AIP types were termed conventional AIP interface and experimental AIP interface, where the latter provided explicit verbal and graphical information about the automatic system. Some alterations were made with regard to both the scenario design and the provision of verbal feedback compared to the HCA-2000 experiment. The hypotheses were specified with reference to a SImple Model of Operator Activity (SIMOA), developed within the HCA-program and thoroughly accounted for in this report. SIMOA constitutes a cyclical model and refers to schema theory. The hypotheses stating that the operators would correctly handle component malfunctions faster than strategy malfunctions, and that workload would be lower, and situation awareness, trust in automation, and quality of cooperation would be higher when component rather than strategy malfunctions occurred, was not supported by the results. However, the hypotheses that operators would correctly handle

  2. A plasma polymerization technique to overcome cerebrospinal fluid shunt infections

    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

  3. Portosystemic Shunt Surgery in Patients with Idiopathic Noncirrhotic Portal Hypertension.

    Karagul, Servet; Yagci, Mehmet Ali; Tardu, Ali; Ertugrul, Ismail; Kirmizi, Serdar; Sumer, Fatih; Isik, Burak; Kayaalp, Cuneyt; Yilmaz, Sezai

    2016-01-01

    BACKGROUND Idiopathic noncirrhotic portal hypertension (INCPH) is a rare disease characterized by increased portal venous pressure in the absence of cirrhosis and other causes of liver diseases. The aim of the present study was to present our results in using portosystemic shunt surgery in patients with INCPH. MATERIAL AND METHODS Patients who had been referred to our Liver Transplantation Institute for liver transplantation and who had undergone surgery from January 2010 to December 2015 were retrospectively analyzed. Patients with INCPH who had undergone portosystemic shunt procedure were included in the study. Age, sex, symptoms and findings, type of portosystemic shunt, and postoperative complications were assessed. RESULTS A total of 1307 patients underwent liver transplantation from January 2010 to December 2015. Eleven patients with INCPH who did not require liver transplantation were successfully operated on with a portosystemic shunt procedure. The mean follow-up was 30.1±19 months (range 7-69 months). There was no mortality in the perioperative period or during the follow-up. Two patients underwent surgery again due to intra-abdominal hemorrhage; one had bleeding from the surgical site except the portacaval anastomosis and the other had bleeding from the h-graft anastomosis. No patient developed encephalopathy and no patient presented with esophageal variceal bleeding after portosystemic shunt surgery. Shunt thrombosis occurred in 1 patient (9.9%). Only 1 patient developed ascites, which was controlled medically. CONCLUSIONS Portosystemic shunt surgery is a safe and effective procedure for the treatment of patients with INCPH. PMID:27194018

  4. A model based diagnostic system for the identification of malfunctioning components using a constraint propagation paradigm

    A commonly recognized failing of traditional rule-based diagnostic expert systems is the inability to recognize problems outside the range of expertise. In turn, the capability of such expert systems is limited to well-known problems. Contrary to the traditional approach, a model-based system has a potential to diagnose unexpected malfunctions. In this paper, a model-based diagnostic system for the isolation of malfunctioning components using constraint propagation paradigm - the CBDS, the Constraint Based Diagnostic System - is presented. The CBDS consists of (1) symbolic representation of plant model as a knowledge base, and (2) constraint propagation paradigm as a diagnostic inference engine. In the CBDS, a plant model contains information about intended behaviour of components that are organized in a component model library, as well as information about how the components are interconnected. As a diagnostic inference engine, the CBDS uses the general idea of model-based diagnosis to identify malfunctioning components. (author). 15 refs, 8 figs

  5. Muzzle shunt augmentation of conventional railguns

    Parker, J.V. (Los Alamos National Lab., NM (United States). Physics Div.)

    1991-01-01

    This paper reports on augmentation which is a technique for reducing the armature current and hence the armature power dissipation in a plasma armature railgun. In spite of the advantages, no large augmented railguns have been built, primarily due to the mechanical and electrical complexity introduced by the extra conductors required. it is possible to achieve some of the benefits of augmentation in a conventional railgun by diverting a fraction {phi} of the input current through a shunt path at the muzzle of the railgun. In particular, the relation between force and armature current is the same as that obtained in an n-turn, series-connected augmented railgun with n = 1/(1 {minus} {phi}). The price of this simplification is a reduction in electrical efficiency and some additional complexity in the external electrical system.

  6. CONTROLLED SHUNT REACTORS FOR ELECTRIC NETWORKS

    Dolgopolov A.G.,

    2011-12-01

    Full Text Available The article presents results of the research and design of controlled shunt alternative current reactors (CSR. The analysis of domestic and foreign experience of the development and deployment of CSR is performed, the effectiveness of their applications in power systems is assessed and results of the tests of samples CSR-220 kV and above are shown. Constructive features of CSR circuit are described; technical characteristics of the CSR-220, 500 kV are given. The prospects for widespread introduction of CSR for the control of power systems regimes are shown. The application of CSR in combination with other control devices such as FACTS allows, based on high-voltage lines of high capacity, creating controlled transmission lines of new generation, which corresponds to all necessary requirements with time-developing power systems and its associations.

  7. Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT

    Wallace, Adam N.; Bagade, Swapnil; Chatterjee, Arindam; Hicks, Brandon; McKinstry, Robert C. [Barnes Jewish Hospital, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Washington University School of Medicine, St. Louis, MO (United States); Vyhmeister, Ross [Washington University School of Medicine, St. Louis, MO (United States); Ramirez-Giraldo, Juan Carlos [Siemens Healthcare, Malvern, PA (United States)

    2015-03-17

    Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. The new protocol lowered the average volume CT dose index from 15.2 to 9.2 mGy representing a 39 % reduction (P < 0.01; 95 % CI 35-44 %) and lowered the dose length product from 259.5 to 151.2 mGy/cm representing a 42 % reduction (P < 0.01; 95 % CI 34-50 %). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality. (orig.)

  8. An experimental study of emission and combustion characteristics of marine diesel engine with fuel pump malfunctions

    Presented paper shows the results of the laboratory study on the relation between the chosen malfunctions of a fuel pump and the exhaust gas composition of the marine engine. The object of research is a laboratory four-stroke diesel engine, operated at a constant speed. During the research over 50 parameters were measured with technical condition of the engine recognized as “working properly” and with simulated fuel pump malfunctions. Considered malfunctions are: fuel injection timing delay and two sets of fuel leakages in the fuel pump of one engine cylinder. The results of laboratory research confirm that fuel injection timing delay and fuel leakage in the fuel pump cause relatively small changes in thermodynamic parameters of the engine. Changes of absolute values are so small they may be omitted by marine engines operators. The measuring of the exhaust gas composition shows markedly affection with simulated malfunctions of the fuel pump. Engine operation with delayed fuel injection timing in one cylinder indicates CO2 emission increase and NOx emission decreases. CO emission increases only at high the engine loads. Fuel leakage in the fuel pump causes changes in CO emission, the increase of CO2 emission and the decrease of NOx emission. - Highlights: •Chosen malfunctions of the fuel injection pump of marine engine are simulated. •Changes of thermodynamic parameters of marine engine are analyzed. •Changes of CO, CO2 and NOx emission characteristics of marine engine are analyzed. •Injection pump malfunctions take significant changes in emission characteristics

  9. Leakage Inductance Calculation for Planar Transformers with a Magnetic Shunt

    Zhang, Jun; Ouyang, Ziwei; Duffy, Maeve C.;

    2014-01-01

    The magnetic shunt is generally inserted in a planar transformer to increase the leakage inductance which can be utilized as the series inductor in resonant circuits such as the LLC resonant converter. This paper presents a calculation methodology for the leakage inductance of the transformer with...... a magnetic shunt by means of the stored magnetic energy in the primary and secondary sides of the transformer using the magnetomotive force (MMF) variation method, as well as the stored energy in the shunt based on the reluctance model. The detailed calculation method is described. Both the FEA...

  10. Clopidogrel in infants with systemic-to-pulmonary-artery shunts

    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 related......) or placebo (439 infants), in addition to conventional therapy (including aspirin in 87.9% of infants). The primary efficacy end point was a composite of death or heart transplantation, shunt thrombosis, or performance of a cardiac procedure due to an event considered to be thrombotic in nature before...

  11. Diagnosis and quantitation of left to right shunts using radioisotopes

    After intravenous injection of sup(99m)TcO4 into the femoral vein the count-rate vs. time curve of a lung field is recorded and analysed (Ohio Nuclear Camera ON 110, pdp 11 computer GAMMA 11, hp 5407 computer). Using a modified gamma function area-ratio technique, the size of the left to right shunts is calculated and compared with cardiac catheter results (128 patients). The localisation of the left to right shunt (ASD or VSD) is possible, if the shunt size rises over 30%. The method may be an alternative to oximetry and conventional dilution techniques. (orig.)

  12. Malfunction of the inner ear is the most frequent cause of dizziness

    Klokker, Mads; Vesterhauge, Søren

    2013-01-01

    Half of all dizziness patients suffer from a malfunction of the inner ear and benign paroxysmal positional vertigo causes 25-30% of these malfunctions. During the latest two decades new vestibular test equipment has been developed and has made it possible to refine the vestibular diagnoses...... and consequently treat patients more efficiently. This brief overview describes the benefit of Epley's Omniax Chair, video head impulse tests and the Vestibular Autorotation Test. The need for vestibular rehabilitation programmes and for a closer collaboration between physicians and the social authorities...

  13. Pollutants removal in subsurface infiltration systems by shunt distributing wastewater with/without intermittent aeration under different shunt ratios.

    Pan, Jing; Yuan, Fang; Zhang, Yang; Huang, Linli; Yu, Long; Zheng, Fanping; Cheng, Fan; Zhang, Jiadi

    2016-10-01

    Matrix dissolved oxygen (DO), removal of COD, TP and nitrogen in subsurface infiltration systems (SISs), named SIS A (without intermittent aeration and shunt distributing wastewater), SIS B (with shunt distributing wastewater) and SIS C (with intermittent aeration and shunt distributing wastewater) were investigated. Aerobic conditions were developed in 50cm depth and anoxic or anaerobic conditions were not changed in 80 and 110cm depth by intermittent aeration. Under appropriate shunt ratios, shunt distributing wastewater improved denitrification and had little influence on COD, TP and NH3-N removal. Under the optimal shunt ratio of 1:2 for SIS C, high average removal rates of COD (90.06%), TP (93.17%), NH3-N (88.20%) and TN (85.79%) were obtained, which were higher than those in SIS A (COD: 82.56%, TP: 92.76%, NH3-N: 71.08%, TN: 49.24%) and SIS B (COD: 81.12%, TP: 92.58%, NH3-N: 69.14%, TN: 58.73%) under the optimal shunt ratio of 1:3. PMID:27347804

  14. Gastric varices with spontaneous gastrorenal shunt: treated by retrograde gastrorenal shunt balloon occlusion combined with percutaneous transhepatic gastric varices embolization

    Objective: To evaluate the efficacy and the safety of retrograde gastrorenal shunt balloon occlusion combined with percutaneous transhepatic gastric varices embolization to treat the gastric varices with spontaneous gastrorenal shunt. Methods: From Nov. 2006 to Jun. 2010, retrograde gastrorenal shunt balloon occlusion combined with percutaneous transhepatic gastric varices embolization was performed on 8 patients who had gastric varices with spontaneous gastrorenal shunt. All the patients were men and the age ranged from 40 to 61 years. The balloon catheter was inserted into the spontaneous gastrorenal shunt through the right femoral vein, then percutaneous transhepatic splenic vein venography was performed to identify the number and morphology of gastric varices. After that gastric varices embolization was performed while the balloon catheter was dilated, which was withdrawn one day after the procedure. Results: Technical success of interventional treatment was achieved in all 8 cases with no significant complications. The increase of average portal venous pressure was 5.5 cm H2O (1 cm H2O=0.098 kPa, preoperative 35.0 to 41.0 cm H2O, postoperative 39.0 to 45.5 cm H2O). After follow up of 1 to 46 months, no recurrence haemorrhage occurred. Conclusion: Retrograde gastrorenal shunt balloon occlusion combined with percutaneous transhepatic gastric varices embolization can be safely performed and could be one of the effective choices for patients who had gastric varices with spontaneous gastrorenal shunt, which is not suitable to treat by the endoscopic sclerotherapy. (authors)

  15. Effects of acute normovolemic hemodilution on intrapulmonary shunting and oxygenation during one-lung ventilation in dogs%急性等容血液稀释对犬单肺通气期间肺分流与氧合的影响

    马宁; 李树人; 槐庆元

    2001-01-01

    目的观察犬单肺通气期间,不同程度急性等容血液稀释对肺分流和氧供、氧耗等的影响.方法 12只健康杂种犬,基础麻醉后插入双腔气管导管,股动、静脉置管.稳定30分钟(HD0)后,以血定安等速置换全血,分别达到轻度(HDl)、中度(HD2)、重度(HD3)和极重度(HD4)血液稀释四个阶段.每阶段均分为双肺通气(TLV)和单肺通气(OLV),分别于各阶段TLV、OLVl5分钟后测量分流(Qs/Qt)及氧供(DO2)、氧耗(VO2)等各指标变化.结果随着HD程度的加深,平均动脉压、心输出量、肺血管阻力(PVR)、平均肺动脉压(MPAP)、氧分压、DO2等趋于降低,氧摄取率(ERO2)、血乳酸、Qs/Qt趋于增加,到HD3、HD4时已出现DO2-VO2依赖性降低及无氧酵解征象.与TLV时相比,OLV期间HD0、HD1及HD2组PVR、MPAP增高明显(P<0.01),而HD3、HD4组变化不大(P>0.05);OLV时QS/Qt增加更为明显,HD2、HD3及HD4组分别较基值增加74%、164%及177%(P<0.01).结论缺氧、ANHD均为影响Qs/Qt与氧合的重要因素,OLV时ANHD应以不低于中度为准.%Objective To evaluate the effects of different degrees of acute normovolemic hemodilution (ANH) on intrapulmonary shunting, oxygen delivery and consumption during one-lung ventilation(OLV) in dogs. Methods Twelve healthy mongrel dogs weighing 18-22 kg were anesthetized with Ⅳ pentobarbital sodium 20mg.kg-1, scopolamine 0.3 mg and pancuronium 0.2 mg. kg-1 and intubated with a left-sided Carlen' s tube. Correct positioning of the tube was verified by auscultation and by visual inspection after thoracotomy at the end of the experiment. The dogs were mechanically ventilated with 100% oxygen. PET CO2 was maintained between 4.67-6.00 kPa. ECG and rectal temperature were continuously monitored. An intravenous line was established for infusion of Lacted Ringer solution. SwanGanz catheter was inserted via femoral vein on one side for sampling of mixed venous blood and measurement of cardiac output (CO) by

  16. [A simple peritoneovenous shunt in the treatment of chronic ascites].

    Pafko, P; Hladík, P

    2001-02-01

    The authors describe their own initial experience with a peritoneo-venous shunt in otherwise incurable ascites. It is a simple procedure which is more satisfactory than the formerly used technique of implantation of Le Veen's system. PMID:12881921

  17. [Sapheno-peritoneal shunt for the treatment of ascites].

    Nagy, Z; Gyurkovics, E; Kaliszky, P; Kupcsulik, P

    2001-08-01

    For the surgical treatment of drug resistant ascites caused by hepatic cirrhosis usually different types of valvular plastic tubes are used, implanted as peritoneo-venous shunts. These shunts drain the ascites into the jugular vein. In the 1st Surgical Department of the Semmelweis University Budapest we have performed 267 peritoneo-venous shunt operations. We introduced a new method using an autolog venous graft with a peritoneo-venous anastomosis, that drains the ascites into the saphenous, then femoral vein. So far we performed 5 such interventions. The early results suggest that sapheno-peritoneal shunt can be successfully used for treatment of ascites. With this operation complications of plastic grafts are avoidable. PMID:11550492

  18. A case of breast cancer involving a ventriculoperitoneal shunt.

    Kamei, Mirei; Kikuchi, Nobuyuki; Ichimura, Homare; Chujo, Masao; Takahashi, Yoshiaki; Sugio, Kenji

    2016-12-01

    An 84-year-old woman was examined for an enlargement of an induration in the left breast. A ventriculoperitoneal shunt had been placed for postoperative normal pressure hydrocephalus of a cerebral hemorrhage, and it had penetrated the mass according to the computed tomography findings. Breast cancer was diagnosed after a close examination; however, close observation was selected because her family rejected treatment. She developed somnolence 7 months after the initial examination, and ventricular dilatation and expansion of the low-density region around the ventricle were noted on computed tomography, suggesting that the enlarged tumor had excluded the shunt and caused obstruction. The growth of breast carcinoma involving a shunt tube can be the cause of obstruction of a ventriculoperitoneal shunt. Our findings suggest that a breast lesion should be evaluated at both pre- and postoperation. PMID:26943684

  19. Ventriculoperitoneal Shunt Infection Caused by Actinomyces neuii subsp. neuii▿

    Watkins, Richard R.; Anthony, Kathy; Schroder, Suzanne; Hall, Gerri S.

    2008-01-01

    Actinomyces neuii subsp. neuii is a rare isolate in clinical specimens. The organism was previously designated CDC coryneform group 1 and was renamed in 1994. A case of a ventriculoperitoneal shunt infection caused by this organism is described.

  20. Hearing Loss in Patients with Shunt-Treated Hydrocephalus.

    Panova, Margarita V; Geneva, Ina E; Madjarova, Kalina I; Bosheva, Miroslava N

    2015-01-01

    Hearing loss is a common manifestation of the long-term complications in patients with shunt treated hydrocephalus along with motor development disturbance, cognitive and visual impairment, epilepsy and endocrine disorders. The aim of the present study was to investigate the alterations of hearing in patients with shunt treated hydrocephalus of non-tumor etiology and at least one year after implantation of ventriculo-peritoneal shunt, as well as their impact on the quality of life of patients. The study included 70 patients (age range 1.25 years - 21.25 years) with shunted non-tumor hydrocephalus and at least one year after placement of the shunt system. Hearing alterations were proved by measuring the brainstem auditory evoked potentials (BAEP) for children up to 5 years of age and children with mental retardation; audiograms was used for children older than 5 years with normal neuro-psychological development (NPD). Of the 70 studied patients 17 (24%) had hearing loss (10 bilateral and 7-unilateral) and all of them had sensorineural hearing loss, which is associated with low weight at birth, posthemorrhagic hydrocephalus and brainstem symptoms at the time of diagnosis of hydrocephalus. Hearing pathology was found more often in shunt-treated patients with NPD retardation, poor functional status and low quality of life. Children with shunt-treated hydrocephalus have hearing loss of sensorineural type. Children with brain stem symptomatology at diagnosing hydrocephalus and children with post-hemorrhagic hydrocephalus show higher risk of hearing loss. Children with shunted hydrocephalus and hearing loss show lower NPD, lower quality of life and lower functional status. PMID:27180348

  1. Decompression of superior vena cava during bidirectional Glenn shunt

    Kulkarni Venugopal; Mudunuri Ravikiran; Mulavisala Krishnaprasad; Byalal R

    2009-01-01

    Patients undergoing bi-directional Glenn shunt for various congenital anomalies of the heart will have their superior vena cava (SVC) clamped during the procedure. The duration of the procedure is variable, ranging from five to 30 minutes. This can affect the cerebral perfusion due to raised venous pressure [Cerebral blood flow = Mean arterial pressure − (Intracranial pressure + Central venous pressure)]. Shunting away the SVC blood is a well known technique to counter this probl...

  2. Shunt loudspeaker techniques for use as liners for engine nacelles

    Lissek, Hervé

    2009-01-01

    In this paper, the liner concept is an electroacoustic transducer which acoustic impedance can be changed by electrical means, be it passive or active. Among the different ways to obtain variable acoustic properties on an electroacoustic transducer's voicing face is the shunting of the transducer's electrical input. With such shunt devices, the acoustic impedance that the transducer's membrane presents to the acoustic field takes account of an acoustic equivalent of the electrical load that c...

  3. Longitudinal Shunt Slot Excitation by Wiggly Ridge Substrate Integrated Waveguide

    Mehdi Salemi; Mehdi Moradian; Reza Safian

    2014-01-01

    Application of a substrate integrated waveguide with wiggly ridge shape is presented for excitation longitudinal shunt slot antenna. Two main design equations for design substrate integrated waveguide structure and get parameters of structures, for longitudinal shunt slot excitation by shape wiggly ridge in substrate integrated waveguide are modified. Proposed method is used by applied the crinkle shape to ridge for ridge substrate integrated waveguide structure. This shape wiggly ridge just...

  4. Cerebral Venous Thrombosis after Ventriculoperitoneal Shunting: A Case Report

    Matsubara, Teppei; AYUZAWA, Satoshi; AOKI, Tsukasa; Ikeda, Go; SHIIGAI, Masanari; Matsumura, Akira

    2013-01-01

    Ventriculoperitoneal shunting (VPS) is a simple procedure, but there are several potential complications. We describe the first reported case of cerebral venous thrombosis (CVT) after VPS. A 69-year-old man suffering from normal pressure hydrocephalus underwent left VPS. Two months later he developed CVT and cerebral venous hemorrhage in the left frontal lobe. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed the thrombus formation just adjacent to the shunt tube. One pos...

  5. Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

    To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis

  6. 40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

    2010-07-01

    ... sources referenced from 40 CFR part 63, subpart F, by the compliance date specified in that subpart. The... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6...

  7. 40 CFR 62.14645 - What happens during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false What happens during periods of startup... Limits § 62.14645 What happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during periods of CISWI unit startup, shutdown,...

  8. Malfunctioned and Fractured Penile Prosthesis Caused by Cross Placement: Case Report

    Nihat Karakoyunlu

    2015-05-01

    Full Text Available Penile prosthesis is a functional option for patients who have erectile dysfunction after failed medical and intracavernosal treatments. Malleable penile prosthesis is a good alternative. Penile prosthesis implantation is a surgical process. Seldomly complications occur. In this study we presented a 61 y old man who has malfunctioned and broken penile prosthesis due to cross implantation.

  9. Baclofen overdose from possible intrinsic malfunction of SynchroMed II pump.

    Davanzo, Justin R; Rizk, Elias

    2015-08-01

    This is a case report illustrating an overdose of baclofen in a 10-year-old boy due to a likely malfunction of a SynchroMed II pump. This ultimately necessitated a pump replacement. One-year follow-up showed no further incidents of baclofen overdose, with multiple pump refills. PMID:25978532

  10. DEVELOPMENT OF AN EXPERT SYSTEM FOR DIAGNOSIS MALFUNCTIONS OF ENGINES OF DIESEL POWER STATIONS

    Laptev V. N.

    2015-12-01

    Full Text Available The article considers development of expert system based on semantic networks for diagnosis malfunctions of the diesel power stations engines. The method allows developing expert systems via objectoriented programming language. The expert system allows to identify the problem without involving additional staff: at the start and overheats of the engine, when there is low power, with decreasing pressure etc

  11. Validation of a novel method for detecting and stabilizing malfunctioning areas in fuel cell stacks

    Müller, Martin; Hirschfeld, Julian; Lambertz, Rita; Schulze Lohoff, Andreas; Lustfeld, Hans; Pfeifer, Heinz; Reißel, Martin

    2014-12-01

    In this paper a setup for detecting malfunctioning areas of MEAs in fuel cell stacks is described. Malfunctioning areas generate electric cross currents inside bipolar plates. To exploit this we suggest bipolar plates consisting not of two but of three layers. The third one is a highly conducting layer and segmented such that the cross currents move along the segments to the surface of the stack where they can be measured by an inductive sensor. With this information a realistic model can be used to detect the malfunctioning area. Furthermore the third layer will prevent any current inhomogeneity of a malfunctioning cell to spread to neighbouring cells in the stack. In this work the results of measurements in a realistic cell setup will be compared with the results obtained in simulation studies with the same configuration. The basis for the comparison is the reliable characterisation of the electrical properties of the cell components and the implication of these results into the simulation model. The experimental studies will also show the limits in the maximum number of segments, which can be used for a reliable detection of cross currents.

  12. Malfunctioned and Fractured Penile Prosthesis Caused by Cross Placement: Case Report

    Nihat Karakoyunlu; Sercan Sarı; Harun Ozdemir; Hikmet Topaloglu; Ugur Ozok; Levent Sagnak; Hamit Ersoy

    2015-01-01

    Penile prosthesis is a functional option for patients who have erectile dysfunction after failed medical and intracavernosal treatments. Malleable penile prosthesis is a good alternative. Penile prosthesis implantation is a surgical process. Seldomly complications occur. In this study we presented a 61 y old man who has malfunctioned and broken penile prosthesis due to cross implantation.

  13. Analytical study of ventilation-system behavior using TVENT1 under simulated blower malfunctions

    A large, complex ventilation system at the Los Alamos National Laboratory's Plutonium Processing Facility was modeled and analyzed using a computer code called TVENT1. Useful information was obtained about the system's operating characteristics when subjected to potential blower malfunctions. This report provides an excellent example for a potential user of TVENT1 for application to an actual system

  14. Minimally Invasive-Endoscopic Intraventricular Neurosurgery

    Full Text Available ... ultimately result in difficulty with vision, strokes and death. I'm sure probably some people are watching ... an acute shunt malfunction can manifest. And sudden death has been described in endoscopic third ventriculostomy reclosure. ...

  15. 40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... subpart A of 40 CFR part 60 apply. Continuous Emission Monitoring ... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of...

  16. 40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

  17. 40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown,...

  18. 40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown,...

  19. 40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown,...

  20. First Report of Ventriculoperitoneal Shunt Infection due to Cyberlindnera fabianii

    Jonathan Baghdadi

    2015-01-01

    Full Text Available Fungal infections in the central nervous system (CNS are associated with significant morbidity and death. Transient fungemia in immunocompetent patients without any other risk factors for fungemia has been suggested as a possible mechanism that may lead to serious fungal ventriculoperitoneal (VP shunt infections, but evidence is lacking. The clinical spectrum, diagnosis, and optimal therapy of Cyberlindnera fabianii infections remain to be determined. We describe the first case of CNS infection due to C. fabianii that occurred in an immunocompetent adult with a VP shunt. Spontaneous translocation with yeast that is not part of the normal gastrointestinal flora in the setting of ingestion of multiple servings of a fermentation product was the likely source from which Cyberlindnera fabianii gained entrance into the VP shunt system, causing meningitis in this patient. The authors conclude that, in view of the high morbidity associated with yeast infection of the CNS, long-term antifungal therapy should be strongly considered in cases where the VP shunt cannot be completely removed. Transient fungemia may lead to invasive disease in an immunocompetent host with VP shunt, even in the absence of any other risk factors for fungemia and even after remote placement of the VP shunt.

  1. Shunt switched resistor regulator with diode snubber

    Ekstrand, J.

    1989-03-21

    This patent describes a shunt switched resistor regulator power supply for supplying a variable amount of power to a load comprising: a rectifier means for accepting AC input voltage and converting it to DC output voltage at a positive and a negative terminal; first, second, third, and fourth nodes wherein the first and the fourth nodes are coupled to the positive and negative terminals, respectively; a current limiting resistor coupled between the first and second nodes; a capacitor coupled between the second and fourth nodes; a resistor having parasitic inductance coupled between the second and third nodes; a switch coupled between the third and fourth nodes; and a diode having its anode coupled to the third node and having its cathode coupled to the second node; means coupled to the load terminals for sensing the power being delivered to the load and for controlling the switch to have a duty cycle which results in the desired load current flowing through and a desired voltage appearing across the load in accordance with control input signals received at a control input.

  2. How automation malfunctions influence operator performance. study plan for the HCA-2000 experiment

    Skjerve, Ann Britt Miberg; Andresen, Gisle; Saarni, Ray; Skraaning, Gyrd Jr.

    2001-03-15

    This report presents the Study Plan for the Human-Centred Automation Programme's experiment in year 2000. The purpose of the experiment is to examine how two types of automation malfunctions influence operator performance when operators work from two different types of interfaces for presenting information about the activities of the automatic system. The experiment is performed using the Nokia Research Simulator of HAMMLAB. Licensed operators act as experimental participants. They participate in crews consisting of two operators. The experimental design applied is a 2x2(x3) within-subject design. The independent variable of automation malfunction type has two levels. These are defined with reference to slips-mistakes distinction that has been used to classify human errors. A control-system component malfunction (CSCM) constitutes an automation slip, i.e. a failure in execution. A situation-dependent strategy malfunction (SDSM) constitutes an automation mistake, i.e. a failure in planning. The independent variable of automation-information presentation (AIP) type also has two levels. These are defined with reference to the degree in which the interfaces depict information about the activity of the automatic system, and relate to the idea of operators' mental isolation from automation. The conventional AIP interface provides limited information about the activity of the automatic system. The experimental AIP interface provides information about the activity of the main automatic devices and offers verbal semantically meaningful feedback. The overall experimental hypotheses state that operators will correctly handle CSCM faster than SDSM, and that automation malfunctions will be dealt with correctly faster from the experimental rather than a conventional AIP interface. They also state that the influence of the automation-malfunction type in general will be stronger than the influence of the AIP interface type. The experiment includes an additional set of

  3. Transjugular intrahepatic portosystemic shunt for the treatment of portal vein thrombus:its current status

    The prevalence of portal vein thrombosis in the general population is about 1.1%, while it is about 10%-25% in the cirrhotic patients. The severe clinical complication in patients with acute portal vein thrombosis is ischemic intestinal infarction when the thrombus extends to the mesenteric venous arch. The complications include bleeding due to gastroesophageal varices, ascites and deterioration of live function in the patients with chronic portal vein thrombosis. The recently-published Practice Guidelines indicate that the treatment of portal vein thrombosis includes anticoagulation,thrombolysis, transjugular intrahepatic portosystemic shunt (TIPS) and surgical thrombectomy. TIPS has some advantages in treating portal vein thrombus. It can directly and effectively re-canalize the occluded portal vein. Moreover, it can accelerate portal flow and prevent recurrent thrombosis after the shunt is well-established. The disadvantages of TIPS include technical difficulties and potential complications. However, percutaneous transhepatic, transsplenic and transmesenteric approaches well facilitate the TIPS procedure. Additionally, preoperative evaluation of portal vein anatomy can provide a safe and effective choice in treating patients with portal cavernoua caver who are going to receive TIPS. Nevertheless, in the absence of relevant prospective studies, the application of TIPS for the management of portal vein thrombosis is still limited. (authors)

  4. Laparoscopy for ventriculoperitoneal shunt implantation and revision surgery

    Fernando; Campos; Gomes; Pinto; Matheus; Fernandes; de; Oliveira

    2014-01-01

    Ventriculoperitoneal shunting(VPS) is a widely accepted technique for the treatment of hydrocephalus. The probability of shunt dysfunction is pretty high throughout life. Laparoscopy has become a valuable tool to perform VPS and treat abdominal complications. An electronic literature search was performed to reveal the published data relating laparoscopy and ventriculoperitoneal shunt in Medline, Embase, Scielo and Lilacs databases. The keywords employed were “laparoscopy” OR “laparoscopic surgery” AND “ventriculoperitoneal shunt” OR “shunt” AND “surgery” OR “implantation” OR “revision” OR “complication”. No high quality trials were developed comparing conventional laparotomic incision vs laparoscopic approach. Both approaches have evolved and currently there are less invasive options for laparotomy, like periumbilical small incisions; and for laparoscopy, like smaller and less incisions. Operating room time, blood loss and hospital stay may be potentially smaller in laparoscopic surgery and complications are probably the same as laparotomy. In revision surgery for abdominal complications after VPS,visualization of whole abdominal cavity is fundamental to address properly the problem and laparoscopic approach is valuable once it is safe, fast and much less invasive than laparotomy. Ventriculoperitoneal shunting is a widely accepted technique for the treatment of hydrocephalus. Laparoscopy assisted shunt surgery in selected cases might be a less invasive and more effective option for intrabdominal manipulation. The laparoscopic approach allows a better catheter positioning, lysis of fibrotic bundles and peritoneal inspection as well, without any additional complication.

  5. Multiple Chaotic Central Pattern Generators with Learning for Legged Locomotion and Malfunction Compensation

    Ren, Guanjiao; Chen, Weihai; Dasgupta, Sakyasingha;

    2015-01-01

    on a simulated annealing algorithm. In a normal situation, the CPGs synchronize and their dynamics are identical. With leg malfunction or disability, the CPGs lose synchronization leading to independent dynamics. In this case, the learning mechanism is applied to automatically adjust the remaining legs...... chaotic CPG controller has difficulties dealing with leg malfunction. Specifically, in the scenarios presented here, its movement permanently deviates from the desired trajectory. To address this problem, we extend the single chaotic CPG to multiple CPGs with learning. The learning mechanism is based...... in a physical simulation of a quadruped as well as a hexapod robot and finally in a real six-legged walking machine called AMOSII. The experimental results presented here reveal that using multiple CPGs with learning is an effective approach for adaptive locomotion generation where, for instance, different body...

  6. [Massive endocardial thrombosis in a patient with a peritoneo-jugular shunt for refractory ascites: the therapeutic success of tissue plasminogen activator and defibrotide].

    Sacchetti, C; Pederzoli, S; Tamborrino, E; Grandi, M

    1994-01-01

    The authors report a case of a patient with a refractory ascites due to extrahepatic portal thrombosis in course of idiopathic thrombocythemia. A peritoneovenous shunt was applied and as a late complication a massive thrombosis of the intracardiac portion of the duct developed. Thrombolysis was obtained with tissue plasminogen activator at doses usually administered for acute myocardial infarction. Prophylaxis of recurrence was pursued with pictomide and defibrotide. PMID:8079040

  7. Comparison of Common Methods in Dynamic Response Predictions of Rotor Systems with Malfunctions

    Hongliang Yao; Qian Zhao; Qi Xu; Bangchun Wen

    2014-01-01

    The efficiency and accuracy of common time and frequency domain methods that are used to simulate the response of a rotor system with malfunctions are compared and analyzed. The Newmark method and the incremental harmonic balance method are selected as typical representatives of time and frequency domain methods, respectively. To improve the simulation efficiency, the fixed interface component mode synthesis approach is combined with the Newmark method and the receptance approach is combined ...

  8. An Experimental Study of Emission and Combustion Characteristics of Marine Diesel Engine with Fuel Injector Malfunctions

    Kowalski Jerzy

    2016-01-01

    Full Text Available The presented paper shows the results of the laboratory study on the relation between chosen malfunctions of a fuel injector and composition of exhaust gas from the marine engine. The object of research is a marine 3-cylinder, four-stroke, direct injection diesel engine with an intercooler system. The engine was loaded with a generator and supercharged. The generator was electrically connected to the water resistance. The engine operated with a load between 50 kW and 250 kW at a constant speed. The engine load and speed, parameters of the turbocharger, systems of cooling, fuelling, lubricating and air exchange, were measured. Fuel injection and combustion pressures in all cylinders of the engine were also recorded. Exhaust gas composition was recorded by using a electrochemical gas analyzer. Air pressure, temperature and humidity were also recorded. Emission characteristics of the engine were calculated according to ISO 8178 standard regulations. During the study the engine operated at the technical condition recognized as „working properly” and with simulated fuel injector malfunctions. Simulation of malfunctions consisted in the increasing and decreasing of fuel injector static opening pressure, decalibration of fuel injector holes and clogging 2 neighboring of 9 fuel injector holes on one of 3 engine cylinders.

  9. Development of expert system on personal computer for diagnosis of nuclear reactor malfunctions

    An expert system on a personal computer has been developed for diagnosis of malfunction of the fast experimental reactor 'JOYO'. Prolog-KABA is used as the language. The system diagnoses the event which causes scram or set-back of the control rod after an alarm at steady state operation. The knowledge base (KB) consists of several sub-KBs and a meta-KB. Using the forward chaining, the meta-KB decides which sub-KB should be accessed. The cause of the malfunction is identified in the sub-KB using the backward chaining. The terms expressing the characteristics of the events are involved in the production rules as attributes in order to use the Prolog function of pattern matching and back-tracking for efficient inference. The total number of the rules in the system is about 400. The experiments using the plant simulator of 'JOYO' have shown that malfunctions are successfully identified by the diagnosis system. It takes about 10s for each diagnosis using the 16-bits personal computer, PC-9801 VM. (author)

  10. Effects of an interatrial shunt on rest and exercise hemodynamics

    Kaye, David; Shah, Sanjiv J; Borlaug, Barry A; Gustafsson, Finn; Komtebedde, Jan; Kubo, Spencer; Magnin, Chris; Maurer, Mathew S; Feldman, Ted; Burkhoff, Daniel

    2014-01-01

    BACKGROUND: A treatment based on an interatrial shunt device has been proposed for counteracting elevated pulmonary capillary wedge pressure (PCWP) in patients with heart failure and mildly reduced or preserved ejection fraction (HFpEF). We tested the theoretical hemodynamic effects of this...... approach with the use of a previously validated cardiovascular simulation. METHODS AND RESULTS: Rest and exercise hemodynamics data from 2 previous independent studies of patients with HFpEF were simulated. The theoretical effects of a shunt between the right and left atria (diameter up to 12 mm) were...... determined. The interatrial shunt lowered PCWP by ~3 mm Hg under simulated resting conditions (from 10 to 7 mm Hg) and by ~11 mm Hg under simulated peak exercise conditions (from 28 to 17 mm Hg). Left ventricular cardiac output decreased ~0.5 L/min at rest and ~1.3 L/min at peak exercise, with corresponding...

  11. Association of distinct intracranial pial and dural arteriovenous shunts

    Vilela, P. [Neuroradiology Dept., Garcia de Orta Hospital (Portugal); Brugge, K. ter; Willinsky, R. [Toronto Western Hospital, Div. of Neuroradiology, Toronto, ON (Canada)

    2001-09-01

    Intracranial pial and dural arteriovenous shunts may exist at different sites in the same patient. The etiology, natural history and treatment of these associated conditions have not been completely determined. We reviewed the records of 765 cases of pial arteriovenous malformation and 137 dural arteriovenous fistulae and malformations. We selected eight patients with both pial and dural arteriovenous shunts, separate anatomically, with distinct feeding arteries and draining veins, representing 1 % of pial and 17 % of dural shunts. Presentation was related to the dural lesion in 5 cases (62.5 %) and to the pial malformation in three (37.5 %). Treatment of these lesions should be considered separately based on their angioarchitecture and natural history. (orig.)

  12. Endovascular occlusion of high-flow intracranial arteriovenous shunts: technical note

    van Rooij, Willem Jan; Sluzewski, Menno

    2007-01-01

    Endovascular closure of high-flow arteriovenous (AV) shunts in intracranial AV malformations or pial fistulas is technically challenging. In this paper, we illustrate two simple methods to occlude large high-flow AV shunts in a controlled manner.

  13. Computer analysis of radiocardiograms of patients with intracardiac shunts

    In 112 patients catheterized for congenital heart disease, radiocardiographic data have been collected by right atrial injection of sup(113m)In. Four scintillation detectors were used to monitor the activity changes in the heart, lungs and head. The heart measurements were done with both frontal and left lateral detectors, the latter being constructed for better collimation and efficiency. The CAMAC system and PDP-9 computer served for data collection, storage analysis, and display. Data were collected at 10 or 20 points per second and the pulsatile output of heart curves recorded. Since radiocardiograms in patients with shunts are complex, a computer program (PULSE) incorporating a pulsatile heart model was written for radiocardiogram simulation and analysis. The model consists of a series of compartments pulsating alternately. From each compartment a certain fraction of indicator is ejected into the next compartment and added to the indicator retained there. Each cardiac chamber is represented by one compartment, while pulmonary and systemic circulation are represented by a series of paired number of compartments. For shunt simulation a certain fraction can be ejected backward or forward along the series. In order to shorten the computation the model was fitted only to the end-diastolic and end-systolic states of the compartments. In left-to-right haemodynamically significant shunts the heart and lung curves show recirculation peaks. In right-to-left shunts the head curve detects the early arrival of indicator and shows a biphasic character. The addition of a computer for data acquisition and for pulsatile model simulation and analysis makes it possible to estimate shunt flows. Estimates correlate well with results of standard shunt measurements. (author)

  14. Endophthalmitis associated with Glaucoma Shunt Intraluminal Stent Exposure

    Kerr, Nathan M; Ruddle, Jonathan B; Ang, Ghee Soon

    2016-01-01

    ABSTRACT Endophthalmitis post glaucoma drainage implant (GDI) surgery is rare, often associated with tube or plate exposure. We report a case of endophthalmitis following glaucoma shunt intraluminal stent exposure in a patient who underwent Baerveldt glaucoma implant surgery. Endophthalmitis following manipulation of intraluminal stents is a rare complication of GDIs but potentially vision threatening condition that needs to be carefully screened for and treated immediately. How to cite this article: Kwon HJ, Kerr NM, Ruddle JB, Ang GS. Endophthalmitis associated with Glaucoma Shunt Intraluminal Stent Exposure. J Curr Glaucoma Pract 2016;10(1):36-37.

  15. Unusual manifestations of infection following shunt: An interesting case summary

    Raj Kumar

    2007-01-01

    Full Text Available One 3 years male child was operated for a large vermian pilocytic astrocytoma. He developed fever and features of raised intracranial pressure after 2 weeks to require external ventricular drainage and ventriculoperitoneal shunt subsequently. The cause of fever could not be established even after thorough repeated investigations in this child and he did not respond to changing antibiotics during next 2 weeks. He responded dramatically to empirical antituberculous chemotherapy, which was started on the basis of history of contact with tuberculosis. The role of uncommon shunt infection is discurred to explain the clinical scenario in this case.

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

    Jain, Deepak, E-mail: deepakjain02@yahoo.com; Arora, Ankur, E-mail: aroradrankur@yahoo.com [Institute of Liver and Biliary Sciences, Department of Radiology (India); Deka, Pranjal, E-mail: drpranjaldeka@gmail.com [Institute of Liver and Biliary Sciences, Department of Hepatopancreatobiliary Surgery (India); Mukund, Amar, E-mail: dramarmukund@gmail.com; Bhatnagar, Shorav, E-mail: drshorav@yahoo.com [Institute of Liver and Biliary Sciences, Department of Radiology (India); Jindal, Deepti, E-mail: deepijindal@rediffmail.com; Kumar, Niteen, E-mail: drniteenkumar@gmail.com; Pamecha, Viniyendra, E-mail: viniyendra@yahoo.co.uk [Institute of Liver and Biliary Sciences, Department of Hepatopancreatobiliary Surgery (India)

    2013-08-01

    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.

  17. Initial clinical experience with a new pulsed dye laser device in angioplasty of limb ischemia and shunt fistula obstructions

    Selective plaque ablation with laser radiation at 405-530 nm in vitro has been reported. The possibilities are investigated of a new pulsed dye laser device for in vivo recanalization of arteries in ischemic lower limbs and stenoses/occlusions of arterio-venous hemo-dialysis shunt fistulae. A specially designed 9F or 7F multifiber catheter was used for treatment of 10 patients with lower limb artery obliterations and 11 patients with malfunctioning hemodialysis access fistulae (HAF). The recanalization technical success was 5/5 in the iliac arteries (IA), 4/5 in the superficial femoral arteries (SFA), and 11/11 in the HAF. Early re-occlusions occurred in one SFA and IA, respectively, caused by very bad run-off. There was one clinically insignificant SFA perforation. Additional balloon angioplasty was considered necessary in 10/16 lesions. Mean ankle-arm index increased from 0.68 to 0.97. With two exceptions all HAF patients were re-integrated in the dialysis program. Pulsed dye laser angioplasty promises to be an effective and fast method for plaque ablation debulking. The first clinical experience confirms previous in vitro results. In particular laser recanalization may become the method of choice for treatment of rigid HAF obstructions and it seems to be superior to vascular surgery or balloon angioplasty alone. (author). 15 refs.; 2 figs

  18. Risk factors associated with hemodialysis central venous catheter malfunction; a retrospective analysis of a randomized controlled trial

    Ward, David R.; Moist, Louise M.; MacRae, Jennifer M; Scott-Douglas, Nairne; Zhang, Jianguo; Tonelli, Marcello; Lok, Charmaine E.; Soroka, Steven D; Hemmelgarn, Brenda R

    2014-01-01

    Background We previously reported a reduction in central venous catheter (CVC) malfunction when using once-weekly recombinant tissue-plasminogen activator (rt-PA) as a locking solution, compared with thrice-weekly heparin. Objectives To identify risk factors for CVC malfunction to inform a targeted strategy for rt-PA use. Design Retrospective analysis. Setting Canadian hemodialysis (HD) units. Patients Adults with newly placed tunnelled upper venous system CVCs randomized to a locking solutio...

  19. NH4+ triggers the release of astrocytic lactate via mitochondrial pyruvate shunting

    Lerchundi, Rodrigo; Fernández-Moncada, Ignacio; Contreras-Baeza, Yasna; Sotelo-Hitschfeld, Tamara; Mächler, Philipp; Wyss, Matthias T.; Stobart, Jillian; Baeza-Lehnert, Felipe; Alegría, Karin; Weber, Bruno; Barros, L. Felipe

    2015-01-01

    Neural activity is accompanied by a transient mismatch between local glucose and oxygen metabolism, a phenomenon of physiological and pathophysiological importance termed aerobic glycolysis. Previous studies have proposed glutamate and K+ as the neuronal signals that trigger aerobic glycolysis in astrocytes. Here we used a panel of genetically encoded FRET sensors in vitro and in vivo to investigate the participation of NH4+, a by-product of catabolism that is also released by active neurons. Astrocytes in mixed cortical cultures responded to physiological levels of NH4+ with an acute rise in cytosolic lactate followed by lactate release into the extracellular space, as detected by a lactate-sniffer. An acute increase in astrocytic lactate was also observed in acute hippocampal slices exposed to NH4+ and in the somatosensory cortex of anesthetized mice in response to i.v. NH4+. Unexpectedly, NH4+ had no effect on astrocytic glucose consumption. Parallel measurements showed simultaneous cytosolic pyruvate accumulation and NADH depletion, suggesting the involvement of mitochondria. An inhibitor-stop technique confirmed a strong inhibition of mitochondrial pyruvate uptake that can be explained by mitochondrial matrix acidification. These results show that physiological NH4+ diverts the flux of pyruvate from mitochondria to lactate production and release. Considering that NH4+ is produced stoichiometrically with glutamate during excitatory neurotransmission, we propose that NH4+ behaves as an intercellular signal and that pyruvate shunting contributes to aerobic lactate production by astrocytes. PMID:26286989

  20. Locally Resonant Gaps of Phononic Beams Induced by Periodic Arrays of Resonant Shunts

    CHEN Sheng-Bing; WEN Ji-Hong; WANG Gang; HAN Xiao-Yun; WEN Xi-Sen

    2011-01-01

    @@ Periodic arrays of shunted piezoelectric patches are employed to control the propagation of elastic waves in phononic beams.Each piezo-patch is connected to a single resistance-inductance-capacitance shunting circuit.Therefore,the resonances of the shunting circuits will produce locally resonant gaps in the phononic beam.However,the existence of locally resonant gaps induced by resonant shunts has not been clearly proved by experiment so far.In this work,the locally resonant gap in a piezo-shunted phononic beam is investigated theoretically and verified by experiment.The results prove that resonances of shunting circuits can produce locally resonant gaps in phononic beams.%Periodic arrays of shunted piezoelectric patches are employed to control the propagation of elastic waves in phononic beams. Each piezo-patch is connected to a single resistance-inductance-capacitance shunting circuit. Therefore, the resonances of the shunting circuits will produce locally resonant gaps in the phononic beam. However, the existence of locally resonant gaps induced by resonant shunts has not been clearly proved by experiment so far. In this work, the locally resonant gap in a piezo-shunted phononic beam is investigated theoretically and verified by experiment. The results prove that resonances of shunting circuits can produce locally resonant gaps in phononic beams.

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

    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.

  2. High-Flow Arterio-Hepatic Venous Shunt in Hepatocellular Carcinoma: Use of Multi-Electrode Radiofrequency for Shunt Obliteration

    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.

  3. High-Flow Arterio-Hepatic Venous Shunt in Hepatocellular Carcinoma: Use of Multi-Electrode Radiofrequency for Shunt Obliteration

    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

  4. Peritoneo-vulvar catheter extrusion after shunt operation.

    Nagulic, M; Djordjevic, M; Samardzic, M

    1996-04-01

    We report an unusual case of catheter extrusion through the external genitalia. between the labium majus and the labium minus, in a 6-month-old hydrocephalic baby. The event occurred 5 months after placement of a ventriculoperitoneal shunt. PMID:8739410

  5. Factorial analysis in diagnosis of left-to-right shunts

    Factor analysis (FA) extracts curves and images from a dynamic study with minimal operator intervention. This study applies FA to the left-to-right (L-R) shunt diagnosis, using it with deconvolution and gamma fitting techniques and comparing it to current procedures. 14 patients with a L-R shunt confirmed by catheterization and 10 normal subjects were studied. A first-pass ventriculogram was gathered in list mode for 25 sec after bolus injection of 15-20 mCi Tc99m. .5 sec frames were created. For FA 3 factors were requested, the dixel size was 4 by 4 pixels and 30 dixels were analyzed. The heart was masked out for the analysis. Three images and curves were obtained: venous input, lungs and background. The lung curve was deconvolved by the venous input curve using the lagged normal algorithm. The unit impulse response was used to obtain a calculated output lung curve. Gamma functions were fitted on this curve and area ratios yielded the Qp/Qs. Only FA with deconvolution separates the shunt patients from the control group with a p <0.001. Qp/Qs for the shunt group was 2.30, SD .54 and the control group was 1.12, SD .07. The best correlation with oximetry was obtained with this technique, r=.87 and SEE .28. The FA lung curve has excellent counting statistics derived from 48% of the total counts, thus the improvement of results

  6. Congenital extrahepatic portosystemic shunt associated with heterotaxy and polysplenia

    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.)

  7. Longitudinal Shunt Slot Excitation by Wiggly Ridge Substrate Integrated Waveguide

    Mehdi Salemi

    2014-07-01

    Full Text Available Application of a substrate integrated waveguide with wiggly ridge shape is presented for excitation longitudinal shunt slot antenna. Two main design equations for design substrate integrated waveguide structure and get parameters of structures, for longitudinal shunt slot excitation by shape wiggly ridge in substrate integrated waveguide are modified. Proposed method is used by applied the crinkle shape to ridge for ridge substrate integrated waveguide structure. This shape wiggly ridge just under longitudinal slot. The slot is place at centreline of substrate integrated waveguide (siw in center of waveguide and on dielectric copper surface, top of substrate integrated waveguide. Amount of crinkle depth of waveguide centreline is proportional with needful radiation of slot and normalized conductance could be much to increase crinkle depth. In this paper the shunt element distribution assumption for prposed structure is spoted. Results of simulation show, proposed method is suitable candidate for replacing with usual longitudinal shunt slot. Structure’s useful is, low fabrication price, small profile and adaptation with microstrip circuit. Also slot place along waveguide centerline and wiggle depth substitute slot offset, therefore this procedure can suppress second order bim in array containing suggestion structure.

  8. Large area shunt defect free GaAs solar cells

    Shunt defects have been found to be the type of defect that can degrade and cause failure in GaAs solar cells. Because of their catastrophic effects, it is necessary to insure that no shunt defects are formed in the solar cell. A technique for fabricating large area shunt defect free GaAs solar cells has been investigated. A Be doped GaAlAs window layer was grown directly on a n-type GaAs substrate by isothermal liquid phase epitaxial growth (ILPE). By growing directly on the GaAs substrate and not growing the usual buffer, absorber, collector, and window layer combination, the fabrication is simplified and yields can be large. It was found that the Be from the liquid GaAlAs melt diffused into the GaAs to form a complete collector layer. Because the collector is complete, a shunt defect free solar cell is produced. The results of the ILPE growth are reported for both 5.1 cm2 and 0.12 cm2 solar cells. The technique is very versatile and may be used to fabricate larger area solar cells

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

    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.

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

    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

  11. Multidetector row CT study of percutaneous transhepatic intrahepatic portosystemic shunt

    Objective: To investigate imaging features of the liver, portal vein and hepatic vein or transhepatic inferior vena cava in patients with severe liver cirrhosis in multidetector row computed tomography (MDCT), and assess the feasibility, safety and clinical significance of percutaneous transhepatic intrahepatic portosystemic, shunt (PTIPS). Methods: Fifty patients with severe liver cirrhosis confirmed by clinical data and imaging examination were enrolled in this study. Simulation of intrahepatic portosystemic shunt by percutaneous transhepatic, approach is as follows. The right midaxillary line (the eighth oi ninth intercostal space) was selected as puncture point A the right branch of portal vein was puncture point B, transhepatic inferior vena cava was puncture point C, and the distal part of right portal vein was D. A-B-C connection is simulated as percutaneous transhepatic puncture tract, C-B-D connection is simulated as portosystemic shunt tract. After tri-phase contrast-enhanced CT scanning, postprocessing images through multiple planner reconstruction (MPR) were obtained. The data were indicated statistically by x-bar±s. And 9.5% confidence interval for mean was calculated. Anatomic relationship among the right portal vein, transhepatic inferior vena cava, hepatic artery and bile duct were analyzed for all patients. Results: The length of the needle (A-B-C) is (145.7±14.8) mm. The curvature of the needle (the angle of A-B line and B-C line) is (145.0±9.9) . The length of transhepatic shunt tract (B-C) is (42.7±7.2) mm. The length of the shunt tract (C-B-D) is (117.7±11.6) mm; The angle of the shunt tract (the angle of B-C line and B-D line) is (108.5±5.9)°. In 24/50 patients, transhepatic inferior vena cava locate in the dorsal of the right portal vein, in 26/50 patients they are in the same plane. In all patients, the right branches of hepatic artery and bile duct locate in the ventral of the right portal vein. Conclusion: The procedure of PTIPS is

  12. Right-to-left shunt with hypoxemia in pulmonary hypertension

    Mastroïanni Bénédicte

    2009-03-01

    Full Text Available Abstract Background Hypoxemia is common in pulmonary hypertension (PH and may be partly related to ventilation/perfusion mismatch, low diffusion capacity, low cardiac output, and/or right-to-left (RL shunting. Methods To determine whether true RL shunting causing hypoxemia is caused by intracardiac shunting, as classically considered, a retrospective single center study was conducted in consecutive patients with precapillary PH, with hypoxemia at rest (PaO2 2 (AaPO2, and with transthoracic contrast echocardiography performed within 3 months. Results Among 263 patients with precapillary PH, 34 patients were included: pulmonary arterial hypertension, 21%; PH associated with lung disease, 47% (chronic obstructive pulmonary disease, 23%; interstitial lung disease, 9%; other, 15%; chronic thromboembolic PH, 26%; miscellaneous causes, 6%. Mean pulmonary artery pressure, cardiac index, and pulmonary vascular resistance were 45.8 ± 10.8 mmHg, 2.2 ± 0.6 L/min/m2, and 469 ± 275 dyn.s.cm-5, respectively. PaO2 in room air was 6.8 ± 1.3 kPa. Qs/Qt was 10.2 ± 4.2%. AaPO2 under 100% oxygen was 32.5 ± 12.4 kPa. Positive contrast was present at transthoracic contrast echocardiography in 6/34 (18% of patients, including only 4/34 (12% with intracardiac RL shunting. Qs/Qt did not correlate with hemodynamic parameters. Patients' characteristics did not differ according to the result of contrast echocardiography. Conclusion When present in patients with precapillary PH, RL shunting is usually not related to reopening of patent foramen ovale, whatever the etiology of PH.

  13. Multidisciplinary team malfunctioning on a state hospital unit: a case study.

    Gomez, E A; Ruiz, P; Langrod, J

    1980-01-01

    The use of multidisciplinary teams in the care of psychiatric patients can be countertherapeutic unless attention is paid to the dynamics of team functioning. The authors present a case study of team malfunctioning on an inpatient unit in a state hospital that resulted from staff's role confusion and insecurity. Patient care was relegated to second place as major interpersonal conflicts among the staff were played out along ethnic and cultural lines. Resolution of the conflicts required identifying their source, clarifying staff roles, and initiating a special inservice training program focused primarily on the needs of paraprofessional staff. PMID:7353821

  14. An Experimental Study of Emission and Combustion Characteristics of Marine Diesel Engine with Fuel Injector Malfunctions

    Kowalski Jerzy

    2016-01-01

    The presented paper shows the results of the laboratory study on the relation between chosen malfunctions of a fuel injector and composition of exhaust gas from the marine engine. The object of research is a marine 3-cylinder, four-stroke, direct injection diesel engine with an intercooler system. The engine was loaded with a generator and supercharged. The generator was electrically connected to the water resistance. The engine operated with a load between 50 kW and 250 kW at a constant spee...

  15. Peroral extrusion of ventriculoperitoneal shunt: Case report and review of literature

    Sridhar K

    2009-01-01

    Full Text Available A rare complication of ventriculoperitoneal shunting (VPS is bowel perforation by the peritoneal catheter of the shunt tube. Rarer still is the peroral extrusion of such a perforated shunt. A two-month-old infant with history of neonatal meningitis, presented with a large head, bulging fontanelle, and hydrocephalus. A VPS was inserted. The child was doing well till the age of eight months, when following vomiting, the peritoneal end of the shunt came out through the mouth. The shunt was removed and antibiotics started. At follow up after 12 months, the child was doing well. Peroral extrusion of the shunt tube needs prompt treatment, including removal of the extruded shunt tube, and attention to bowel perforation and possible cerebrospinal fluid infection. The reported patient is younger than the five cases reported earlier. Strategies in the management of this complication are reviewed. An individualized approach is essential for the successful treatment of this rare complication.

  16. Lumboatrial shunt in a patient with Crouzon syndrome complicated by pseudotumor cerebri.

    Sankey, Eric W; Khattab, Mohamed H; Elder, Benjamin D; Goodwin, C Rory; Rekate, Harold L; Rigamonti, Daniele

    2015-09-01

    A 25-year-old man with Crouzon syndrome complicated by pseudotumor cerebri and multiple shunt failures presented with progressive back and neck pain, intermittent headaches, and associated vomiting secondary to shunt infection. Due to his previous history of repeated failure of both ventriculoperitoneal and lumboperitoneal (LP) shunting procedures, the decision was made to place a lumboatrial (LA) shunt via an approach through the internal jugular vein. The procedure was uncomplicated and the man's symptoms were relieved. Despite significant improvement, the LA shunt limited his exercise tolerance, and as an avid runner and weight lifter, he requested reconversion back to an LP shunt. At a follow-up of 20months, he continued to do well both clinically and radiographically. This case report summarizes the successful placement and use of an LA shunt for the treatment of intracranial hypertension in the setting of Crouzon syndrome. PMID:26021731

  17. An Enhanced Data Visualization Method for Diesel Engine Malfunction Classification Using Multi-Sensor Signals

    Yiqing Li

    2015-10-01

    Full Text Available The various multi-sensor signal features from a diesel engine constitute a complex high-dimensional dataset. The non-linear dimensionality reduction method, t-distributed stochastic neighbor embedding (t-SNE, provides an effective way to implement data visualization for complex high-dimensional data. However, irrelevant features can deteriorate the performance of data visualization, and thus, should be eliminated a priori. This paper proposes a feature subset score based t-SNE (FSS-t-SNE data visualization method to deal with the high-dimensional data that are collected from multi-sensor signals. In this method, the optimal feature subset is constructed by a feature subset score criterion. Then the high-dimensional data are visualized in 2-dimension space. According to the UCI dataset test, FSS-t-SNE can effectively improve the classification accuracy. An experiment was performed with a large power marine diesel engine to validate the proposed method for diesel engine malfunction classification. Multi-sensor signals were collected by a cylinder vibration sensor and a cylinder pressure sensor. Compared with other conventional data visualization methods, the proposed method shows good visualization performance and high classification accuracy in multi-malfunction classification of a diesel engine.

  18. Multiple components malfunction scenarios--a classification technique with emphasis on shared-cause events

    The authors of this study, under EPRI sponsorship, undertook the task of formulating a working definition for common-cause failure; however, they discovered such a wide diversity of event scenarios that no simple definition proved to be helpful. The alternative was to devise a classification system for all event scenarios, but designed with the ability to handle shared-cause phenomena. The objectives of pursuing this line of investigation are three-fold: 1) develop a logical and credible method for dissecting and understanding actual component malfunction scenarios in order to identify multiple events where the shared-cause phenomenon is important; 2) support various analyses, including probabilistic risk assessments, with a means of segregating data for use in statistical and modeling evaluations; and 3) assess the effectiveness of defensive strategies that may be employed where a need to reduce the impact of shared-cause malfunctions exists. Having established the clear distinction between root causes and component causes and between failures and functional unavailabilities, an event scenario can be readily broken down into its elementary parts wherein each component has an identifiable cause of its unavailability and each scenario has an overall classification. The heart of this system is a device called a Cause-Effect Logic Diagram which depicts the interrelationship between causes and components

  19. Different degree in proteasome malfunction has various effects on root growth possibly through preventing cell division and promoting autophagic vacuolization.

    Xianyong Sheng

    Full Text Available The ubiquitin/proteasome pathway plays a vital role in plant development. But the effects of proteasome malfunction on root growth, and the mechanism underlying this involvement remains unclear. In the present study, the effects of proteasome inhibitors on Arabidopsis root growth were studied through the analysis of the root length, and meristem size and cell length in maturation zone using FM4-64, and cell-division potential using GFP fusion cyclin B, and accumulation of ubiquitinated proteins using immunofluorescence labeling, and autophagy activity using LysoTracker and MDC. The results indicated that lower concentration of proteasome inhibitors promoted root growth, whereas higher concentration of inhibitors had the opposite effects. The accumulation of cyclin B was linked to MG132-induced decline in meristem size, indicating that proteasome malfunction prevented cell division. Besides, MG132-induced accumulation of the ubiquitinated proteins was associated with the increasing fluorescence signal of LysoTracker and MDC in the elongation zone, revealing a link between the activation of autophagy and proteasome malfunction. These results suggest that weak proteasome malfunction activates moderate autophagy and promotes cell elongation, which compensates the inhibitor-induced reduction of cell division, resulting in long roots. Whereas strong proteasome malfunction induces severe autophagy and disturbs cell elongation, resulting in short roots.

  20. [Surgical treatment of refractory ascites with peritoneovenous shunt].

    Massari, R; Fulgente, R; Marinelli, S; Romessis, M

    1995-01-01

    Leveen and associates described a peritoneo-venous shunt which proved to be useful in patients with intractable ascites. Medical therapy, paracentesis and peritoneovenous shunt have been compared, but there is uncertainty about their relative merits. Therefore, the leveen device has be placed in last years in an increasing number of patients: it has not been shown by prospective trials to prolong survival significantly, although it may shorten hospitalization and improve the quality of life. A number of early and late complications were described but they do not influence the general results: origin and features of such complications are discussed as well as their prevention and treatment and personal cases are presented. Selection of patients and careful surgical procedure seems to be mandatory for better results. PMID:8706187

  1. Endoscopic third ventriculostomy has no higher costs than ventriculoperitoneal shunt

    Benicio Oton de Lima

    2014-07-01

    Full Text Available Objective: To evaluate the cost of endoscopic third ventriculostomy (ETV compared to ventriculoperitoneal shunt (VPS in the treatment of hydrocephalus in children. Method: We studied 103 children with hydrocephalus, 52 of which were treated with ETV and 51 with VPS in a prospective cohort. Treatment costs were compared within the first year after surgery, including subsequent surgery or hospitalization. Results: Twenty (38.4% of the 52 children treated with VPS needed another procedure due to shunt failure, compared to 11 (21.5% of 51 children in the ETV group. The average costs per patient in the group treated with ETV was USD$ 2,177,66±517.73 compared to USD$ 2,890.68±2,835.02 for the VPS group. Conclusions: In this series there was no significant difference in costs between the ETV and VPS groups.

  2. Management of intracranial dural arteriovenous shunts in adults

    Sarma, Dipanka; Brugge, Karel ter E-mail: karel.terbrugge@uhn.on.ca

    2003-06-01

    Dural arteriovenous shunts are abnormal arteriovenous communications within the dura. They are thought to be an acquired condition in adults and can present with a variety of clinical features, ranging from benign bruits to intracranial hemorrhage and neurological deficits. The presentation and natural history of these shunts is largely determined by the pattern of venous drainage. Knowledge of natural history and careful study of the angioarchitexture by angiography is therefore mandatory for correct management of these lesions. In this review, principles of management in adults and the various factors that influence treatment decisions are discussed, with a focus on endovascular therapy. Retrograde leptomeningeal or cortical venous drainage has a strong correlation with adverse clinical events and the requirement for aggressive management in this situation is highlighted. Indications for endovascular treatment, therapeutic goals, approaches and techniques are reviewed. The role of surgical treatment is also briefly discussed.

  3. Management of intracranial dural arteriovenous shunts in adults

    Dural arteriovenous shunts are abnormal arteriovenous communications within the dura. They are thought to be an acquired condition in adults and can present with a variety of clinical features, ranging from benign bruits to intracranial hemorrhage and neurological deficits. The presentation and natural history of these shunts is largely determined by the pattern of venous drainage. Knowledge of natural history and careful study of the angioarchitexture by angiography is therefore mandatory for correct management of these lesions. In this review, principles of management in adults and the various factors that influence treatment decisions are discussed, with a focus on endovascular therapy. Retrograde leptomeningeal or cortical venous drainage has a strong correlation with adverse clinical events and the requirement for aggressive management in this situation is highlighted. Indications for endovascular treatment, therapeutic goals, approaches and techniques are reviewed. The role of surgical treatment is also briefly discussed

  4. Cerebral venous thrombosis after ventriculoperitoneal shunting: a case report.

    Matsubara, Teppei; Ayuzawa, Satoshi; Aoki, Tsukasa; Ikeda, Go; Shiigai, Masanari; Matsumura, Akira

    2014-01-01

    Ventriculoperitoneal shunting (VPS) is a simple procedure, but there are several potential complications. We describe the first reported case of cerebral venous thrombosis (CVT) after VPS. A 69-year-old man suffering from normal pressure hydrocephalus underwent left VPS. Two months later he developed CVT and cerebral venous hemorrhage in the left frontal lobe. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed the thrombus formation just adjacent to the shunt tube. One possible cause is compression of the cortical vein after brain shift and/or tension of the cortical vein due to intracranial hypotension. A protein C deficiency was also detected. Surgeons should be aware that cerebral venous thrombosis can occur after VPS. PMID:24257484

  5. A Technique for Shunt Active Filter meld micro grid System

    A. Lumani

    2015-08-01

    Full Text Available The proposed system presents a control technique for a micro grid connected hybrid generation system ith case study interfaced with a three phase shunt active filter to suppress the current harmonics and reactive power present in the load using PQ Theory with ANN controller. This Hybrid Micro Grid is developed using freely renewable energy resources like Solar Photovoltaic (SPV and Wind Energy (WE. To extract the maximum available power from PV panels and wind turbines, Maximum power point Tracker (MPPT has been included. This MPPT uses the “Standard Perturbs and Observe” technique. By using PQ Theory with ANN Controller, the Reference currents are generated which are to be injected by Shunt active power filter (SAPFto compensate the current harmonics in the non linear load. Simulation studies shows that the proposed control technique performs non-linear load current harmonic compensation maintaining the load current in phase with the source voltage.\\

  6. Shunted-Josephson-junction model. I. The autonomous case

    Belykh, V. N.; Pedersen, Niels Falsig; Sørensen, O. H.

    1977-01-01

    The shunted-Josephson-junction model: the parallel combination of a capacitance, a phase-dependent conductance, and an ideal junction element biased by a constant current, is discussed for arbitrary values of the junction parameters. The main objective is to provide a qualitative understanding of...... current-voltage curves are presented. The case with a time-dependent monochromatic bias current is treated in a similar fashion in the companion paper....

  7. Harmonics and Reactive Power Compensation Using Shunt Hybrid Filter

    R. Sriranjani; M. Geetha; S. Jayalalitha

    2013-01-01

    The supply current is distorted by the nonlinear load such UPS, DC drives, AC drives and arc furnace. This current harmonics derates the electrical equipments. Thus the current harmonics are reduced from the supply line using Shunt Hybrid filter. The Hysteresis controller controls the active filter thus the supply current tracks the reference fundamental current extracted by the synchronous reference frame unit. So supply current is free from harmonics and also it provides harmonic compensati...

  8. Transjugular Intrahepatic Portosystemic Shunts in Patients with Hepatic Malignancy

    Wallace, Michael J.; Madoff, David C.

    2005-01-01

    Since its first clinical application in 1988, the transjugular intrahepatic portosystemic shunt (TIPS) has emerged as a safe and effective means of managing patients with morbid portal hypertension. Despite the considerable body of literature on TIPS, portal decompression in patients with malignancy has not been sufficiently examined. These patients typically experience sequelae of portal hypertension that requires palliation. The purpose of this article is to review the reported experience w...

  9. Pre-Liver Transplant: Tips Versus Distal Splenorenal Shunt

    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.

  10. Bacteremia and "Endotipsitis" following transjugular intrahepatic portosystemic shunting

    Mizrahi Meir; Roemi Lilach; Shouval Daniel; Adar Tomer; Korem Maya; Moses Alon; Bloom Alan; Shibolet Oren

    2011-01-01

    AIM: To identify all cases of bacteremia and suspected endotipsitis after Transjugular intrahepatic portosystemic shunting (TIPS) at our institution and to determine risk factors for their occurrence. METHODS: We retrospectively reviewed records of all patients who underwent TIPS in our institution between 1996 and 2009. Data included: indications for TIPS, underlying liver disease, demographics, positive blood cultures after TIPS, microbiological characteristics, treatment and outcome. RESUL...