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

PubMed Central

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

2015-01-01

The aims of this prospective study were to quantify steatosis in dogs with congenital portosystemic shunts using a fat-specific stain, to compare the amount of steatosis in different lobes of the liver, and to evaluate intra- and inter-Observer variability in lipid point counting. Computer-assisted point counting of lipid droplets was undertaken following Oil-Red-O staining in 21 dogs with congenital portosystemic shunts and 9 control dogs. Dogs with congenital portosystemic shunts had significantly more small lipid droplets (< 6 μ) than control dogs (p = 0.0013 and 0.0002, respectively). There was no significant difference in steatosis between liver lobes for either control dogs and CPS dogs. Significant differences were seen between observers for the number of large lipid droplets (> 9 μ) and lipogranulomas per tissue point (p = 0.023 and 0.01, respectively). In conclusion, computer-assisted counting of lipid droplets following Oil Red O staining of liver biopsy samples allows objective measurement and detection of significant differences between dogs with CPS and normal dogs. This method will allow future evaluation of the relationship between different presentations of CPS (anatomy, age, breed) and lipidosis, as well as the impact of hepatic lipidosis on outcomes following surgical shunt attenuation. PMID:23528942

Congenital intrahepatic portosystemic venous shunt and liver mass in a child patient: successful endovascular treatment with an amplatzer vascular plug (AVP).

PubMed

Lee, Sae Ah; Lee, Young Seok; Lee, Kun Song; Jeon, Gyeong Sik

2010-01-01

A congenital intrahepatic portosystemic shunt is a rare anomaly; but, the number of diagnosed cases has increased with advanced imaging tools. Symptomatic portosystemic shunts, especially those that include hyperammonemia, should be treated; and various endovascular treatment methods other than surgery have been reported. Hepatic masses with either an intra- or extrahepatic shunt also have been reported, and the mass is another reason for treatment. Authors report a case of a congenital intrahepatic portosystemic shunt with a hepatic mass that was successfully treated using a percutaneous endovascular approach with vascular plugs. By the time the first short-term follow-up was conducted, the hepatic mass had disappeared.

Congenital Intrahepatic Portosystemic Venous Shunt and Liver Mass in a Child Patient: Successful Endovascular Treatment with an Amplatzer Vascular Plug (AVP)

PubMed Central

Lee, Sae Ah; Lee, Young Seok; Lee, Kun Song

2010-01-01

A congenital intrahepatic portosystemic shunt is a rare anomaly; but, the number of diagnosed cases has increased with advanced imaging tools. Symptomatic portosystemic shunts, especially those that include hyperammonemia, should be treated; and various endovascular treatment methods other than surgery have been reported. Hepatic masses with either an intra- or extrahepatic shunt also have been reported, and the mass is another reason for treatment. Authors report a case of a congenital intrahepatic portosystemic shunt with a hepatic mass that was successfully treated using a percutaneous endovascular approach with vascular plugs. By the time the first short-term follow-up was conducted, the hepatic mass had disappeared. PMID:20808706

Unusual spontaneous porto-systemic shunt: The importance of diagnosing non-anatomical porto-systemic shunts to improve portal flow in pediatric living-related liver transplantation. Case report.

PubMed

Rubio, Juan S; Rumbo, Carolina; Farinelli, Pablo A; Aguirre, Nicolás; Ramisch, Diego A; Paladini, Hugo; D Angelo, Pablo; Barros Schelotto, Pablo; Gondolesi, Gabriel E

2018-03-01

Collateral circulation secondary to liver cirrhosis may cause the development of large PSSs that may steal flow from the main portal circulation. It is important to identify these shunts prior to, or during the transplant surgery because they might cause an insufficient portal flow to the implanted graft. There are few reports of "steal flow syndrome" cases in pediatrics, even in biliary atresia patients that may have portal hypoplasia as an associated malformation. We present a 12-month-old female who received an uneventful LDLT from her mother, and the GRWR was 4.8. During the early post-operative period, she became hemodynamically unstable, developed ascites, and altered LFT. The post-operative ultrasound identified reversed portal flow, finding a non-anatomical PSS. A 3D CT scan confirmed the presence of a mesocaval shunt through the territory of the right gonadal vein, draining into the right iliac vein, with no portal inflow into the liver. The patient was re-operated, and the shunt was ligated. An intraoperative Doppler ultrasound showed adequate portal inflow after the procedure; the patient evolved satisfactorily and was discharged home on day number 49. The aim was to report a case of post-operative steal syndrome in a pediatric recipient due to a mesocaval shunt not diagnosed during the pretransplant evaluation. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Congenital intrahepatic venous shunt as a cause of hepatic encephalopathy].

PubMed

Cosme Jiménez, A; Bujanda Fernández de Piérola, L; Poch Zapiraín, M; Orcolaga Alba, R; Ojeda Pérez, E; Arenas Miravé, J I

1995-11-01

Macroscopic intrahepatic portosystemic shunts are extremely rare and may be due to liver injury, congenital vascular malformations or pathologic collaterals secondary to portal hypertension. Forty-eight cases have been reported in the literature up to 1994 with 50-60% presenting cerebral manifestations and 40% being associated with cirrhosis. The case of a patient without cirrhosis who was admitted for upper digestive hemorrhage secondary to gastroduodenal ulcer is described. At 48 hours the patient had an episode of hepatic encephalopathy coinciding with bleeding reactivation. Abdominal echography suggested communication between the right portal and suprahepatic veins and posterior angiography confirmed the diagnosis. Color Doppler echography determined shunt and portal vein blood flow. No case of intrahepatic portosystemic venous shunt as a cause of encephalopathy was found to have been reported in the Spanish literature.

Combination therapy using PSE and TIO ameliorates hepatic encephalopathy due to intrahepatic portosystemic venous shunt in idiopathic portal hypertension

PubMed Central

Kojima, Seiichiro; Ito, Hiroyuki; Takashimizu, Shinji; Ichikawa, Hitoshi; Matsumoto, Tomohiro; Hasebe, Terumitsu

2016-01-01

A 64-year-old woman treated for anemia and ascites exhibited hepatic encephalopathy. Abdominal ultrasonography and computed tomography (CT) showed communication between the portal vein and the middle hepatic vein, indicating an intrahepatic portosystemic venous shunt (PSS). Since hepatic encephalopathy of the patient was resistant to medical treatment, interventional radiology was performed for the treatment of shunt obliteration. Hepatic venography showed anastomosis between the hepatic vein branches, supporting the diagnosis of idiopathic portal hypertension (IPH). To minimize the increase in portal vein pressure after shunt obliteration, partial splenic artery embolization (PSE) was first performed to reduce portal vein blood flow. Transileocolic venous obliteration (TIO) was then performed, and intrahepatic PSS was successfully obliterated using coils with n-butyl-2-cyanoacrylate (NBCA). In the present case, hepatic encephalopathy due to intrahepatic PSS in the patient with IPH was successfully treated by combination therapy using PSE and TIO. PMID:27651930

Potential use of metabolic breath tests to assess liver disease and prognosis: has the time arrived for routine use in the clinic?

PubMed

Stravitz, R Todd; Ilan, Yaron

2017-03-01

The progression of liver disease may be unique among organ system diseases in that progressive fibrosis compromises not only the sufficiency of hepatocyte mass but also impairs blood flow to the liver, resulting in porto-systemic shunting. Although liver biopsy as an assessment of fibrosis has become the key biomarker of and target for new therapies, it is invasive and subject to sampling error, and cannot quantify metabolic function or porto-systemic shunting. Measurement of the hepatic venous pressure gradient accommodates some of the deficiencies of biopsy but requires expertise not widely available and misses minor changes in hepatocellular mass and thereby information about metabolic function. Thus, an unmet need in clinical hepatology remains unfulfilled: a noninvasive biomarker which quantitates both the hepatocellular insufficiency and porto-systemic shunting inherent in progressive hepatic fibrosis. Ideally, such a biomarker should correlate with clinical endpoints including liver-related survival and cirrhotic complications, be performed at the point-of-care, and be affordable and easy to use. This review, an expert opinion, summarizes background and recent data suggesting that metabolic breath tests may now meet these requirements and have a valid place in clinical hepatology to supplant the time-honoured assessment of hepatic fibrosis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Correlation between liver volume, portal vascular anatomy, and hepatic perfusion in dogs with congenital portosystemic shunt before and after placement of ameroid constrictors.

PubMed

Zwingenberger, Allison L; Daniel, Leticia; Steffey, Michele A; Mayhew, Philipp D; Mayhew, Kelli N; Culp, William T N; Hunt, Geraldine B

2014-11-01

To correlate changes in hepatic volume, hepatic perfusion, and vascular anatomy of dogs with congenital extrahepatic portosystemic shunts, before and after attenuation with an ameroid constrictor. Prospective study. Dogs (n = 22) with congenital extrahepatic portosystemic shunts. CT angiography and perfusion scans were performed before and after attenuation of a portosystemic shunt with an ameroid constrictor. Changes in hepatic volume, hepatic perfusion, and vascular anatomy were measured. Portal scintigraphy was performed in 8 dogs preoperatively and 22 dogs postoperatively. Dogs with smaller preoperative liver volumes had greater increases in liver volume postoperatively compared with those with larger preoperative liver volumes. Hepatic arterial fraction was increased in dogs preoperatively and returned to normal range after shunt attenuation, and was correlated with increase in liver size and decreased shunt fraction. Three dogs with no visible portal vasculature preoperatively developed portal branches postoperatively. Dogs with smaller preoperative liver volumes had the largest postoperative increase in liver volume. Hepatic arterial perfusion and portal scintigraphy correlate with liver volume and are indicators of successful shunt attenuation. Dogs without visible vasculature on CT angiography had visible portal vasculature postoperatively. © Copyright 2014 by The American College of Veterinary Surgeons.

Post-traumatic hepatic arterial pseudoaneurysm and arterioportal shunt.

PubMed

Maes, J; D'Archambeau, O; Snoeckx, A; Op de Beeck, B; Voormolen, M; Parizel, P M

2010-01-01

The authors report the case of a 21-year-old man who suffered from a blunt abdominal trauma. Initial imaging revealed a liver laceration at the right lobe, a perirenal hematoma of the right kidney and a hematoma of the right adrenal gland. Follow-up MDCT-scan on day 10 after admission showed at the arterial-phase contrast-enhanced study perfusion alterations and two hepatic pseudoaneurysms. The diagnosis of pseudoaneurysm was confirmed and treated angiographically with superselective coil embolization. A follow-up CT-scan on day 17 showed at a nontreated area an arterioportal shunt and a wedge-shaped transient hepatic parenchymal enhancement. This was confirmed angiographically and subsequently treated with coil embolization.

Does hepatic steatosis have an impact on the short term hepatic response after complete attenuation of congenital extrahepatic portosystemic shunts? A prospective study of 20 dogs.

PubMed

Hunt, Geraldine B; Luff, Jennifer; Daniel, Leticia; Zwingenberger, Allison

2014-11-01

To evaluate the relationship between hepatic steatosis and increase in liver size and resolution of shunting after surgical attenuation of congenital extrahepatic portosystemic shunts in dogs. Prospective study. Dogs (n = 20) with congenital extrahepatic portosystemic shunts. Shunts were attenuated using ameroid ring constrictors. Portal blood flow and liver volume were evaluated using computed tomography before and ≥8 weeks after surgery. Hepatic steatosis was quantified by stereological point counting of lipid droplets and lipogranulomas (LG) in liver biopsies stained with Oil-red-O. Associations between steatosis and preoperative liver volume, liver growth after surgery, and development of acquired shunts were evaluated. Acquired shunts developed in 2 dogs (10%). Dogs with larger preoperative liver volumes relative to bodyweight had fewer lipid droplets per tissue point (P = .019). LG per tissue point were significantly associated with age: 0.019 ± 0.06 for dogs <12 months versus 0.25 ± 0.49 for dogs >12 months (P = .007). There was a significant positive association between liver growth after surgery and the number of LG/month of age in dogs >12 months (P = .003). There was no association between steatosis, presence of macrosteatosis, the number of LG or development of acquired shunts. This preliminary study suggests that the presence of hepatic lipidosis and LG has no demonstrable effect on development of acquired shunts or the magnitude of increase in liver volume after attenuation of congenital extrahepatic portosystemic shunts in dogs. © Copyright 2014 by The American College of Veterinary Surgeons.

Deriving the Intrahepatic Arteriovenous Shunt Rate from CT Images and Biochemical Data Instead of from Arterial Perfusion Scintigraphy in Hepatic Arterial Infusion Chemotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozaki, Toshiro, E-mail: ganronbun@amail.plala.or.jp; Seki, Hiroshi; Shiina, Makoto

2009-09-15

The purpose of the present study was to elucidate a method for predicting the intrahepatic arteriovenous shunt rate from computed tomography (CT) images and biochemical data, instead of from arterial perfusion scintigraphy, because adverse exacerbated systemic effects may be induced in cases where a high shunt rate exists. CT and arterial perfusion scintigraphy were performed in patients with liver metastases from gastric or colorectal cancer. Biochemical data and tumor marker levels of 33 enrolled patients were measured. The results were statistically verified by multiple regression analysis. The total metastatic hepatic tumor volume (V{sub metastasized}), residual hepatic parenchyma volume (V{sub residual};more » calculated from CT images), and biochemical data were treated as independent variables; the intrahepatic arteriovenous (IHAV) shunt rate (calculated from scintigraphy) was treated as a dependent variable. The IHAV shunt rate was 15.1 {+-} 11.9%. Based on the correlation matrixes, the best correlation coefficient of 0.84 was established between the IHAV shunt rate and V{sub metastasized} (p < 0.01). In the multiple regression analysis with the IHAV shunt rate as the dependent variable, the coefficient of determination (R{sup 2}) was 0.75, which was significant at the 0.1% level with two significant independent variables (V{sub metastasized} and V{sub residual}). The standardized regression coefficients ({beta}) of V{sub metastasized} and V{sub residual} were significant at the 0.1 and 5% levels, respectively. Based on this result, we can obtain a predicted value of IHAV shunt rate (p < 0.001) using CT images. When a high shunt rate was predicted, beneficial and consistent clinical monitoring can be initiated in, for example, hepatic arterial infusion chemotherapy.« less

Hepatic encephalopathy secondary to a splenorenal shunt that manifested a long time after a liver transplantation.

PubMed

Tomás Pujante, Paula; Jiménez Sánchez, Andrés Francisco; Iglesias Jorquera, Elena; Pons Miñano, José Antonio

2018-04-24

Splenorenal shunts are a rare cause of hyperammonemia and hepatic encephalopathy in the absence of cirrhosis. We report the case of a woman, who presented hepatic encephalopathy, with a normal functioning graft, after 14 years of liver transplantation, confirmed by liver biopsy.

Left-to-right shunt reduction with intra-aortic balloon pump in postmyocardial infarction ventricular septal defect.

PubMed

Testuz, Ariane; Roffi, Marco; Bonvini, Robert Francis

2013-03-01

This case aims to describe the hemodynamic effects of intra-aortic balloon pump (IABP) in patients with ventricular septal defect (VSD) complicating myocardial infarction (MI). A 79-year-old man with no previous cardiovascular history presented to the emergency department with subacute inferior myocardial infarction associated with mild signs of systemic hypoperfusion. A transthoracic echocardiography revealed a large akinesia of the left ventricular inferior wall with preserved global left ventricular ejection fraction, as well as a large VSD in the midinferior portion of the interventricular septum. Coronary angiography showed an occlusion of the mid portion of a dominant circumflex coronary artery. The invasive hemodynamic evaluation showed a sizable left-to-right shunt (Q(p)/Q(s) = 3.1). Activation of the IABP led to an immediate reduction of the shunt (Q(p)/Q(s) = 2.4 = 22% reduction), an increase in systemic cardiac output (from 2.1 L/min to 2.4 L/min = +12%) and a decrease in the systemic vascular resistances (from 2240 to 1920 dyne-sec/cm(5) = 15% reduction). In patients with post-MI VSD, placement of IABP leads to an immediate reduction in left-to-right shunt and as a consequence to an increase in systemic cardiac output, which may allow hemodynamic stabilization of the patient prior to surgical VSD closure. Copyright © 2012 Wiley Periodicals, Inc.

[Application of degree of portal systemic shunting in assessing upper gastrointestinal bleeding in patients with schistosomiasis cirrhosis].

PubMed

Shuai, Ju; Ying, Li; Chang-Xue, Ji; Biao, Zhang

2017-03-27

To discuss the application of the degree of portal systemic shunting in assessing the upper gastrointestinal bleeding in patients with hepatic schistosomiasis. Thirty-three patients with upper gastrointestinal bleeding caused by hepatic schistosomiasis (a bleeding group) and 29 schistosomiasis cirrhosis patients without bleeding (a non-bleeding group) were enrolled as investigation subjects in Jinshan Hospital. The subjects were scanned by the 128 abdominal slice spiral CT. The portal systemic shunting vessels were reconstructed by using thin slab maximum intensity projection (TSMIP) and multiplanar reconstruction (MPR). The degrees of the shunting vessels of the subjects were evaluated and compared, and the relationship between upper gastrointestinal bleeding and the degree of the shunting was analyzed. In the bleeding group, the occurrence rates of the shunting vessels were found as follows: 86.4% in left gastric varices, 68.2% in short gastric varices, 50.0% in esophageal varices, 50.0% in para-esophageal varices, 37.9% in gastric varices, 69.7% in gastric-renal varices, 51.5% in spleen-renal varices, 25.8% in abdominal wall varices, 15.2% in omentum varices, 63.6% in para-splenic varices, 34.8% in umbilical varices, 40.9% in retroperitoneal-paravertebral varices, and 36.4% in mesenteric varices. In the bleeding group, the occurrence rates and the degree of shunt were significantly higher than those in the non-bleeding group in esophageal varices, esophageal vein, left gastric vein and gastric varices (all P < 0.05). CT portal vein reconstruction can accurately display the location, degree and walking of all kinds of shunting vessels. Esophageal varices, esophageal vein, left gastric vein and gastric varices can accurately predict the risk of upper gastrointestinal bleeding in patients with hepatic schistosomiasis. The patents with higher degree of the shunting vessels have a higher risk of gastrointestinal bleeding.

Hepatic encephalomyelopathy in a calf with congenital portosystemic shunt (CPSS)

PubMed Central

Oevermann, Anna; Bley, Tim; Pfister, Patrizia; Miclard, Julien

2008-01-01

A 4-month-old female Holstein Friesian calf was referred to the Veterinary Teaching Hospital, University of Berne, Switzerland for evaluation of ataxia, weakness, apathy and stunted growth. Clinical examination revealed generalized ataxia, propioceptive deficits, decreased menace response and sensibility. Postmortem examination did not reveal macroscopic changes of major organs. Histologically, the brain and the spinal cord lesions were characterized by polymicrocavitation, preferentially affecting the white matter fibers at the junction of grey and white matter and by the presence of Alzheimer type II cells. The liver revealed lesions consistent with a congenital portosystemic shunt, characterized by increased numbers of arteriolar profiles and hypoplasia to absence of portal veins. The pathological investigations along with the animal history and clinical signs indicated a hepatic encephalomyelopathy due to a congenital portosystemic shunt. PMID:18296896

Outcome of intrahepatic portosystemic shunt diagnosed prenatally.

PubMed

Francois, Bérengère; Gottrand, Fréderic; Lachaux, Alain; Boyer, Corinne; Benoit, Bernard; De Smet, Stéphanie

2017-12-01

We analyzed the characteristics of the population with congenital portosystemic shunt diagnosed during the antenatal period and the organization of their perinatal care. This multicentric retrospective study included all the patients with a prenatal diagnosis of congenital portosystemic shunt. Between 1999 and 2015, 12 patients were included. Prenatal diagnosis was done at a median 26.5 weeks of gestation (21-34). All the patients presented intrahepatic CPSS, three of them had associated congenital cardiopathy, and one a Bannayan-Zonana syndrome. Ten patients had simple outcome on conservative treatment, eight of them having a spontaneous closure of their portosystemic shunt within the first 2 years of life. One patient had surgical treatment which failed and he developed a focal nodular hyperplasia. Another patient had radiological interventional closure of his shunt which was complicated by a venal portal thrombosis. Outcome of intrahepatic portosystemic shunt diagnosed prenatally is good in the majority of cases. What is known: • Multiples studies exist on congenital porto systemic shunt but when the diagnosis is done after birth. • The evolution, management, and complication are well known. What is new: • There is very few studies with only patients diagnosed in antenatal and it is a large series of cases. • Outcome of intrahepatic portosystemic shunt diagnosed prenatally is good in the majority of cases.

Hepatic metastases of colorectal cancer: locoregional intra-arterial treatment.

PubMed

Pasetto, Lara Maria; Merenda, Roberto; Pilati, Pierluigi; Sinigaglia, Giulietta; Monfardini, Silvio

2006-01-01

A radical resection alone of colorectal hepatic metastases is possible in only 10-20% of the patients but, when resection and ablation are combined, the rate of radicalism can improve. A regional hepatic intra-arterial chemotherapy infusion (HAI) has been introduced in the clinical practice, as a possible alternative approach to systemic chemotherapy. Nevertheless, the introduction of new systemic therapies with monoclonal antibodies, combined to irinotecan or oxaliplatin, recently improved response rates and overall survival ia these patients. Aiming to evaluate a possible influence of HAI in these new treatments, the most important studies underlining the evolution of intrahepatic administration in recent years are reviewed.

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

PubMed

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

2017-09-01

Large spontaneous portosystemic shunts (SPSS) are seen in a subset of patients with liver disease and medically refractory recurrent/persistent hepatic encephalopathy (MRHE). Shunt occlusion has been shown to improve clinical outcomes. We retrospectively analyzed patient characteristics, SPSS attributes, procedural features, baseline clinical and investigational parameters, neurological outcomes, adverse effects (procedure and portal hypertension related), and risk factors predicting outcomes in liver disease patients undergoing shunt occlusion procedure for MRHE. Between October 2016 and July 2017, 21 patients (Child-Pugh score, CTP 6 to 13) with mean model of end-stage liver disease (MELD) and MELD-sodium scores 15.7 and 19.3 respectively with MRHE [3-cirrhotic Parkinsonism (CP)] were diagnosed to have single or multiple large SPSSs. A total of 29 shunts were occluded (1 surgical, 20 non-surgical). Recurrent and persistent HE and CP markedly improved in the short (n=20, 1 to 3 months), intermediate (n=12, 3 to 6 months), and long (n=7, 6 to 9 months) follow up. None had spontaneous or persistent HE at a median follow up 105 (30 to 329) days (p<0.05). Motor, speech, sleep abnormalities, daily activities of living, and liver disease severity scores improved significantly on follow up. Baseline arterial ammonia showed a statistically significant reduction in all time periods of follow up after shunt occlusion (p<0.05). CTP >11 predicted mortality post shunt occlusion (p=0.04). Embolization of large SPSS in liver disease patients with MRHE and modestly preserved liver function is safe and efficacious and associated with improved quality of life and can function as a bridge to liver transplantation in accurately selected patients.

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

PubMed

Owen, Joshua M; Gaba, Ron Charles

2016-01-01

The objective of this study was to evaluate the concordance between clinical symptoms, Doppler ultrasound (US), and shunt venography for the detection of stent-graft transjugular intrahepatic portosystemic shunt (TIPS) dysfunction. Forty-one patients (M:F 30:11, median age 55 years) who underwent contemporaneous clinical exam, Doppler US, and TIPS venography between 2003 and 2014 were retrospectively studied. Clinical symptoms (recurrent ascites or variceal bleeding) were dichotomously classified as present/absent, and US and TIPS venograms were categorized in a binary fashion as normal/abnormal. US abnormalities included high/low (>190 or <90 cm/s) TIPS velocity, significant velocity rise/fall (>50 cm/s), absent flow, and return of antegrade intra-hepatic portal flow. Venographic abnormalities included shunt stenosis/occlusion and/or pressure gradient elevation. Clinical and imaging concordance rates were calculated. Fifty-two corresponding US examinations and venograms were assessed. The median time between studies was 3 days. Forty of 52 (77%) patients were symptomatic, 33/52 (64%) US examinations were abnormal, and 20/52 (38%) TIPS venograms were abnormal. Concordance between clinical symptoms and TIPS venography was 48% (25/52), while the agreement between US and shunt venography was 65% (34/52). Clinical symptoms and the US concurred in 60% (31/52) of the patients. The sensitivity of clinical symptoms and US for the detection of venographically abnormal shunts was 80% (16/20) and 85% (17/20), respectively. Both clinical symptoms and the US had low specificity (25%, 8/32 and 50%, 16/32) for venographically abnormal shunts. Clinical findings and the US had low concordance rates with TIPS venography, with acceptable sensitivity but poor specificity. These findings suggest the need for improved noninvasive imaging methods for stent-graft TIPS surveillance.

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

PubMed Central

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 <90 cm/s) TIPS velocity, significant velocity rise/fall (>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. PMID:27563495

Patient data system for monitoring shunts.

PubMed

Frank, E; Su, E; Smith, K

1988-01-01

Rapidly locating accurate data on a patient's shunt system is often extremely difficult. We have developed a simple system to fill a perceived need for recording current data on a patients shunt. This system employs an easily updated record in the patient's hospital or clinic chart as well as a wallet-sized data card for the patient or his family to carry. The data in the chart include the configuration of the patient's current shunt system and a graphic record of previous shunt problems. The small patient data card describes the age of the shunt system and its current configuration. We have found that this system provides assistance in the routine follow-up of patients with shunts and plays an extremely necessary role in the emergency evaluation of these patients, particularly when an emergency evaluation is undertaken in facilities distant from the location of regular treatment.

Natural history of major complications in hepatitis C virus-related cirrhosis evaluated by per-rectal portal scintigraphy

PubMed Central

Kawamura, Etsushi; Habu, Daiki; Hayashi, Takehiro; Oe, Ai; Kotani, Jin; Ishizu, Hirotaka; Torii, Kenji; Kawabe, Joji; Fukushima, Wakaba; Tanaka, Takashi; Nishiguchi, Shuhei; Shiomi, Susumu

2005-01-01

AIM: To examine the correlation between the porto-systemic hypertension evaluated by portal shunt index (PSI) and life-threatening complications, including hepatocellular carcinoma (HCC), liver failure (Child-Pugh stage progression), and esophagogastric varices. METHODS: Two hundred and twelve consecutive subjects with HCV-related cirrhosis (LC-C) underwent per-rectal portal scintigraphy. They were allocated into three groups according to their PSI: group I, PSI ≤ 10%; group II, 10%porto-systemic shunting and liver failure non-invasively. It indicates that PSI may play an important role in follow-up of the porto-systemic hypertension gradient for outpatients with LC unlike hepatic venous catheterization. PMID:15991287

Morphology of congenital portosystemic shunts involving the right gastric vein in dogs.

PubMed

White, R N; Parry, A T

2015-07-01

To describe the anatomy of congenital portosystemic shunts involving the right gastric vein in dogs. Retrospective review of a consecutive series of dogs managed for congenital portosystemic shunt. Twenty-two dogs met the inclusion criteria of a congenital portosystemic shunt involving the right gastric vein with recorded intraoperative mesenteric portovenography or computed tomography angiography and gross observations at the time of surgery. Of these, 20 (91%) had a shunt that entered the pre-hepatic caudal vena cava at the level of the epiploic foramen and two (9%) had a shunt that entered the post-hepatic caudal vena cava at the level of the diaphragm. Shunts entering the pre-hepatic caudal vena cava could be further classified into three consistent subdivisions. The morphology of each shunt type described appeared to be a result of an abnormal communication between the left gastric vein and the caudal vena cava, the presence or absence of an abnormal communication between the splenic, left gastric and portal veins and the subsequent development of preferential blood flow through essentially normal portal vessels within the portal venous system. The abnormal communication (shunt) was through the left gastric vein and not the right gastric vein, as might have been expected. This information may help with surgical planning in cases undergoing shunt closure surgery. © 2015 British Small Animal Veterinary Association.

Intrahepatic portosystemic venous shunt: diagnosis by color Doppler imaging.

PubMed

Kudo, M; Tomita, S; Tochio, H; Minowa, K; Todo, A

1993-05-01

Intrahepatic portosystemic venous shunt is a rare clinical entity; only 33 such cases have been reported. It may be congenital, or secondary to portal hypertension. Five patients with this disorder are presented, each of whom was diagnosed by color Doppler imaging, including waveform spectral analysis. One patient with clinical evidence of cirrhosis and portal hypertension had episodes of hepatic encephalopathy and elevated blood levels of ammonia. This patient had a large tubular shunt between the posterior branch of the portal vein and the inferior vena cava. Shunts of this type are considered to be collateral pathways which develop in the hepatic parenchyma as a result of portal hypertension. The other four patients had no evidence of liver disease, and all four evidenced an aneurysmal portohepatic venous shunt within the liver parenchyma. Shunts of this type are considered congenital. The diagnosis of intrahepatic portosystemic venous shunts was established by color Doppler imaging, which demonstrated a direct communication of color flow signals between the portal vein and hepatic vein, in addition to the characterization of the Doppler spectrum at each sampling point from a continuous waveform signal (portal vein) to a turbulent signal (aneurysmal cavity), and finally, to a biphasic waveform signal (hepatic vein). As demonstrated by the five patients, color Doppler imaging is useful in the diagnosis of an intrahepatic portosystemic hepatic venous shunt, and the measurement of shunt ratio may be useful in the follow-up and determining the therapeutic option.

Attenuation of Congenital Portosystemic Shunt Reduces Inflammation in Dogs

PubMed Central

Tivers, Michael S.; Handel, Ian; Gow, Adam G.; Lipscomb, Victoria J.; Jalan, Rajiv; Mellanby, Richard J.

2015-01-01

Liver disease is a major cause of morbidity and mortality. One of the most significant complications in patients with liver disease is the development of neurological disturbances, termed hepatic encephalopathy. The pathogenesis of hepatic encephalopathy is incompletely understood, which has resulted in the development of a wide range of experimental models. Congenital portosystemic shunt is one of the most common congenital disorders diagnosed in client owned dogs. Our recent studies have demonstrated that the pathophysiology of canine hepatic encephalopathy is very similar to human hepatic encephalopathy, which provides strong support for the use of dogs with a congenital portosystemic shunt as a naturally occurring model of human hepatic encephalopathy. Specifically, we have demonstrated an important role for ammonia and inflammation in the development of hepatic encephalopathy in dogs with a congenital portosystemic shunt. Despite the apparent importance of inflammation in driving hepatic encephalopathy in dogs, it is unclear whether inflammation resolves following the successful treatment of liver disease. We hypothesized that haematological and biochemical evidence of inflammation, as gauged by neutrophil, lymphocyte and monocyte concentrations together with C-reactive protein concentrations, would decrease following successful treatment of congenital portosystemic shunts in dogs. One hundred and forty dogs with a congenital portosystemic shunt were enrolled into the study. We found that the proportion of dogs with a monocyte concentration above the reference range was significantly greater in dogs with hepatic encephalopathy at time of initial diagnosis. Importantly, neutrophil and monocyte concentrations significantly decreased following surgical congenital portosystemic shunt attenuation. We also found a significant decrease in C-reactive protein concentrations following surgical attenuation of congenital portosystemic shunts. Our study demonstrates that

Shunt diameter in agenesis of the ductus venosus with extrahepatic portosystemic shunt impacts on prognosis.

PubMed

Shen, O; Valsky, D V; Messing, B; Cohen, S M; Lipschuetz, M; Yagel, S

2011-02-01

Agenesis of the ductus venosus (ADV) is a rare condition in which there are two variants of umbilical vein drainage: intrahepatic shunt or extrahepatic (portosystemic) shunt. It has been posited that the extrahepatic variant carries a poorer prognosis. However, in the absence of associated anomalies there is still a wide variation in outcome. We evaluated the portal system in cases of ADV and aimed to identify parameters that might predict outcome. We conducted a retrospective study of cases of ADV with extrahepatic shunt that had been examined in two centers, and collected new cases prospectively. The route of the shunt was depicted using two-dimensional (2D) and three-dimensional (3D) ultrasound imaging. In an attempt to characterize portal system and shunt developmental variations and their possible impact on outcome, the diameter of the shunt was compared with the diameter of the umbilical vein and the entire portal vasculature was assessed. Poor outcome was defined as persistent morbidity or fetal or neonatal death. Twenty-two cases of ADV were identified: nine retrospectively and 13 prospectively. Aberrant shunts from the umbilical vein were identified to the right atrium, coronary sinus, inferior vena cava (IVC) and iliac vein. In seven of 22 cases (32%) a wide connection was observed. In six of these seven cases (86%) the outcome was poor, including four with severe associated anomalies and two with hepatic dysfunction. In five of these cases, cardiomegaly with tricuspid regurgitation was observed, as well as underdevelopment of the portal system. In only five of 15 cases with a narrow shunt (33%) was the outcome poor, and in all five cases the poor outcome was related to associated anomalies. In cases of ADV with extrahepatic shunt, portal system development is impacted by the diameter of the shunt. If the shunt is narrow, the portal system will have developed normally. A wide shunt is associated with underdevelopment or absence of the portal system. In

Morphology of congenital portosystemic shunts emanating from the left gastric vein in dogs and cats.

PubMed

White, R N; Parry, A T

2013-09-01

To describe the anatomy of congenital portosystemic shunts emanating from the left gastric vein in dogs and cats. A retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. Forty-six dogs and 27 cats met the inclusion criteria of a congenital portosystemic shunt emanating from the left gastric vein. Of the 46 dogs, 28 (61%) had a shunt that entered the left phrenic vein, 10 (22%) had a shunt that entered the post hepatic caudal vena cava and in 8 (17%) the shunt entered the azygos vein. Of the 27 cats, 19 (70%) had a shunt that entered the left phrenic vein and 8 (30%) had a shunt that entered the post hepatic caudal vena cava. The systemic vein into which the shunt entered was consistent showing three common presentations: left gastro-phrenic, left gastro-caval and left gastro-azygos. This information may help with surgical planning in cases undergoing shunt closure surgery. © 2013 British Small Animal Veterinary Association.

Embolization of congenital intrahepatic porto-systemic shunt by n-butyl cyanoacrylate.

PubMed

Gupta, Vivek; Kalra, Naveen; Vyas, Sameer; Sodhi, K S; Thapa, B R; Khandelwal, N

2009-10-01

Congenital intrahepatic portosystemic venous shunt (IHPSVS) is rare vascular anomaly. We present one case of a 14-month male child who presented with global developmental delay. Child had high ammonia levels with low glutamine and high bile salts on the previous investigations and had history of neonatal seizures since day 13 of life. On admission, serum ammonia levels were elevated to 112micromol/L. Other laboratory investigations including liver and renal function test, and electrolytes were normal. He was, diagnosed to have IHPSVS on the basis of Doppler and CT, and treated by embolization with n-butyl cyanoacrylate (glue). A brief review of diagnostic modalities and endovascular management for the IHPSVS is presented including the present case.

Endovascular Management of Refractory Hepatic Encephalopathy Complication of Transjugular Intrahepatic Portosystemic Shunt (TIPS): Comprehensive Review and Clinical Practice Algorithm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pereira, Keith, E-mail: keithjppereira@gmail.com; Carrion, Andres F., E-mail: andres.carrionmonsa@jhsmiami.org; Salsamendi, Jason, E-mail: JSalsamendi@med.miami.edu

Transjugular intrahepatic portosystemic shunt (TIPS) has evolved as an effective intervention for treatment of complications of portal hypertension. The use of polytetrafluoroethylene-covered stents have improved the patency of the shunts and diminished the incidence of TIPS dysfunction. However, TIPS-related refractory hepatic encephalopathy (rHE) poses a significant challenge. Approximately 3–7 % of patients with TIPS develop rHE. Refractory hepatic encephalopathy is defined as a recurrent or persistent encephalopathy despite appropriate medical treatment. Hepatic encephalopathy can be an extremely debilitating complication that profoundly affects quality of life. The approach to management of patients with rHE is complex and typically requires collaboration between differentmore » specialties. Liver transplantation is the ultimate treatment for rHE; however, the ongoing shortage of organ donation markedly limits this treatment option. Alternative therapies such as shunt occlusion or reduction can control symptoms and serve as a ‘bridge’ therapy to liver transplantation. Therefore, interventional radiologists play a key role in the management of these patients by offering a variety of endovascular techniques. The purpose of this review is to highlight some of these endovascular techniques and to develop a therapeutic algorithm that can be applied in clinical practice for the management of rHE.« less

Transjugular Intrahepatic Porto-Systemic Shunt in Patients with Liver Cirrhosis and Model for End-Stage Liver Disease ≥15.

PubMed

Ascha, Mona; Hanouneh, Mohamad; S Ascha, Mustafa; Zein, Nizar N; Sands, Mark; Lopez, Rocio; Hanouneh, Ibrahim A

2017-02-01

It is not known whether transjugular intrahepatic porto-systemic shunt (TIPS) is safe in patients with advanced liver cirrhosis. The aim of our study was to evaluate the impact of TIPS on transplant-free survival in patients with liver cirrhosis and MELD score ≥15. All adult patients who underwent TIPS at our institution between 2004 and 2011 were identified (N = 470). A total of 144 patients had MELD ≥15 at the time of TIPS. These patients were matched 1:1 to patients with liver cirrhosis who did not undergo TIPS based on age and MELD score using the greedy algorithm. Patients were followed up until time of death or liver transplantation. Kaplan-Meier curves and log-rank tests were used to test for differences in survival outcome between the two groups. A total of 288 patients with liver cirrhosis were included, of whom 144 underwent TIPS and 144 did not. The two groups were matched based on age and MELD score and were comparable with regard to gender and ethnicity. Mean MELD and Child-Pugh scores in the study population were 20.9 ± 6.5 and 10.5 ± 1.8, respectively. The most common indication for TIPS was varices (49 %), followed by refractory ascites (42 %). In the first 2 months post-TIPS, there was increased mortality or liver transplantation in patients who had TIPS compared to those who did not, but this did not reach statistical significance (p = 0.07). However, after 2 months, TIPS is associated with 56 % lower risk of dying or needing liver transplantation (p < 0.01) than cirrhotic patients who did not undergo TIPS. In patients with liver cirrhosis and MELD ≥15, TIPS might improve transplant-free survival for patients who live for at least 2 months after the procedure.

Pleurovenous shunt for treating refractory benign pleural effusion.

PubMed

Bayram, Ahmet Sami; Köprücüoğlu, Mustafa; Aygün, Mert; Gebitekin, Cengiz

2008-05-01

We report the case of a 63-year-old female with hepatic cirrhosis due to chronic hepatitis C, successfully treated for refractory nonmalignant hepatic hydrothorax by using a long-term pleurovenous shunt (PVS). After failure of conventional treatment by mechanical pleurodesis, a PVS was inserted to drain the pleural fluid into the right subclavian vein. After 8 months of follow-up, the effusion is well controlled, and the shunt remains patent.

Transhepatic Embolization of Congenital Intrahepatic Portosystemic Venous Shunts with Associated Aneurysms

PubMed Central

Paudel, Kalyan; Hoffer, Eric K.

2015-01-01

Intrahepatic shunts between the portal and systemic venous systems with associated aneurysms are extremely rare. A middle aged woman presented with hepatic encephalopathy and was found to have two intrahepatic portosystemic venous shunts with associated aneurysms. Diagnosis was made by duplex ultrasound and was confirmed with contrast enhanced MRI. Treatment was performed percutaneously with an Amplatzer vascular plug. PMID:26257785

[Small-diameter portosystemic shunts: indications and limitations].

PubMed

Angel Mercado, M; Granados-García, J; Barradas, F; Chan, C; Contreras, J L; Orozco, H; Angel-Mercado, M

1998-01-01

Low diameter porto-systemic shunts for the treatment of portal hypertension bleeding have emerged as a consequence of the technical development of vascular grafts (PTFE) that allow the use of a narrow lumen. The experience with this kind of operation at the Instituto Nacional de la Nutrición Salvador Zubirán, Mexico City during a 6-year period is reported. There were twenty-seven patients with good liver function (Child-Pugh A-B) were operated or electively, average Age 47.5 years (range 17-71), twenty three patients with liver cirrhosis, one with portal fibrosis and three with idiopathic portal hypertension. Operative mortality: 4%. Rebleeding: 14%. Postoperative encephalopathy was observed in 14 of 27, three of them being grade III-IV (11%). In the remaining 11 cases, it was mild and easily controlled. Postoperative angiography showed shunt patency in 81% of the cases; in 33% of the cases, portal vein diameter reduction was shown, as well as two cases with portal vein thrombosis. In 77% of the cases, adequate postoperative quality of life was observed. Survival (Kaplan-Meier): 86% at 12 months and 56% at 60 months. These kinds of shunts are a good alternate choice for patients considered for surgery, in which other portal blood flow preserving procedures (selective shunts, devascularization with transection) are not feasible.

The clinical anatomy of congenital portosystemic venous shunts.

PubMed

Stringer, Mark D

2008-03-01

Congenital portosystemic venous shunts are rare. Their gross anatomy has not been well defined. Four different varieties of congenital portosystemic venous shunts are described in six children seen during a 10-year period, focusing on the anatomy of the shunt as determined by imaging studies and surgery. A detailed review of the literature indicates that congenital portosystemic venous shunts are best classified as: extrahepatic or intrahepatic. Extrahepatic shunts may be further subdivided into portocaval shunts (type 1 end-to-side and type 2 side-to-side) and others. Intrahepatic shunts are due to an abnormal intrahepatic connection between the portal vein and hepatic vein/inferior vena cava or a persistent patent ductus venosus. Additional congenital anomalies, particularly cardiac malformations, may be associated with any type. Some congenital intrahepatic portosystemic venous shunts close spontaneously in infancy; all other congenital portosystemic venous shunts tend to remain patent. To a variable extent, depending largely on the volume and duration of the shunt, affected individuals are at risk of developing hepatic encephalopathy and/or an intrahepatic tumor. The key to understanding the pathogenesis of these shunts lies in the normal developmental mechanisms underlying the formation of the portal vein and inferior vena cava in the embryo. Copyright 2008 Wiley-Liss, Inc.

Interventional embolization of congenital intrahepatic shunts in children.

PubMed

Wu, Lin; Zhao, Lu; Lu, Ying; He, Lan; Hu, Xihong

2016-04-01

Congenital intrahepatic shunts in children are rare and precise treatment strategies have not been established. The purpose of this study was to present our experience with transcatheter embolization in a descriptive case series of congenital intrahepatic shunts in children. We retrospectively studied 10 children with symptomatic congenital intrahepatic shunts who were treated with embolization at our institute between January 2008 and December 2014. Seven children had arteriovenous shunts in association with hepatic hemangiomas, two had arterioportal shunts and one had portosystemic shunts. The major presentations were congestive heart failure and severe anemia in the groups with arteriovenous and arterioportal shunts, respectively. Following embolization, two children died in the arteriovenous group, one from progressive liver dysfunction and the other from abdominal compartment syndrome. One child in the arterioportal group required liver transplantation after initial embolization. With mean post-procedure follow-up of 15 months (range 4-54 months), all the remaining children were well, with resolution of the symptoms. Interventional embolization provides an alternative to surgical ligation or hepatic resection in children with clinically significant intrahepatic shunts. For lesions with complex morphology, embolization may be inadequate and liver transplantation might be the only therapeutic option.

Congenital portosystemic shunts: prenatal manifestations with postnatal confirmation and follow-up.

PubMed

Han, Byoung Hee; Park, Sung Bin; Song, Mi Jin; Lee, Kyung Sang; Lee, Young-Ho; Ko, Sun Young; Lee, Yeon Kyung

2013-01-01

The purpose of this study was to evaluate prenatal sonographic findings that could be helpful for diagnosis of congenital intrahepatic portosystemic venous shunts and the follow-up results. Six neonates with congenital shunts between the portal vein and hepatic vein were enrolled in this study. Prenatal sonography was performed in 5 cases. We categorized the cases according to a previously published classification of intrahepatic portosystemic venous shunts and retrospectively reviewed the prenatal and postnatal sonographic examinations to identify findings that might be helpful for diagnosing shunts prenatally. Follow-up sonographic examinations were done until closure of the shunts. Clinical features were also determined. According to the original reports, intrahepatic portosystemic venous shunts were diagnosed by prenatal sonography in 2 of 5 cases. In the remaining 3 cases, there were suggestive abnormal findings on retrospective review, including an abnormal intrahepatic tubular structure, a prominent hepatic vein, and congestive heart failure. Postnatal sonography showed type 2 shunts in all 6 cases. In 1 case, there were 2 type 2 lesions between two branches of the left portal vein and the middle and left hepatic veins. On follow-up sonography, 5 of the 6 congenital shunts had spontaneously closed by 11 months of age. One case was treated with coil embolization during the neonatal period. Intrauterine growth restriction was the most commonly clinical feature prenatally. Findings such as an abnormal tubular structure, a prominent hepatic vein, and congestive heart failure can be important clues for identifying congenital intrahepatic portosystemic venous shunts on prenatal sonography. The use of prenatal and postnatal sonography is feasible for detection and evaluation of these shunts.

Congenital intrahepatic portosystemic venous shunt presenting with paraparesis as the initial symptom.

PubMed

Torigoe, Masataka; Maeshima, Keisuke; Takeshita, Yasushi

2013-01-01

An 85-year-old woman was hospitalized with rapidly progressive paraparesis without altered consciousness, although she was not definitively diagnosed. She developed acute drowsiness and disorientation several days later. An intrahepatic portosystemic venous shunt (IPSVS) was observed on enhanced computed tomography, and hyperammonemia suggested leakage of neurotoxins from the shunt as the etiology of the patient's symptoms. Her neurological symptoms and hyperammonemia improved following transcatheter shunt embolization. We diagnosed her with hepatic myelopathy, which is a rare complication of liver cirrhosis and portosystemic venous shunts. Hepatic myelopathy resulting from a congenital IPSVS has not been previously reported. A diagnosis of hepatic myelopathy should be ruled out in diagnostically difficult cases of paraparesis.

Festival food coma in cystic fibrosis.

PubMed

Pandit, Chetan; Graham, Christie; Selvadurai, Hiran; Gaskin, Kevin; Cooper, Peter; van Asperen, Peter

2013-07-01

Children with cystic fibrosis liver disease and portal hypertension are at risk of developing acute hepatic encephalopathy. Even in the presence of normal synthetic liver function these children may have porto-systemic shunting. We report a case of an adolosecent who had cystic fibrosis liver disease and presented with life threatening hepatinc encephalopathy. This case illustrates that it is necessary to consider an appropriate dietary regimen in adolosecents with liver disease to prevent hepatic decompensation. Copyright © 2012 Wiley Periodicals, Inc.

A wireless monitoring system for Hydrocephalus shunts.

PubMed

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

2015-08-01

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

Clinical and radiologic manifestations of congenital extrahepatic portosystemic shunts: a comprehensive review.

PubMed

Alonso-Gamarra, Eduardo; Parrón, Manuel; Pérez, Ana; Prieto, Consuelo; Hierro, Loreto; López-Santamaría, Manuel

2011-01-01

Congenital extrahepatic portosystemic shunt (CEPS) is a rare condition in which the portomesenteric blood drains into a systemic vein, bypassing the liver through a complete or partial shunt. Most often, the diagnosis is made primarily with Doppler ultrasonography. Computed tomographic angiography and magnetic resonance angiography are used for further classification of the shunt and assessment of accompanying anomalies. Conventional angiography is necessary when results of the other tests disagree or are inconclusive. CEPS is classified into two types according to the pattern of anastomoses between the portal vein and systemic vein. In type 1, intrahepatic portal venous supply is absent; in type 2, intrahepatic portal venous supply is preserved. Type 1 usually occurs in girls with associated malformations, such as situs ambiguous with polysplenia and congenital heart defects. Associated anomalies are less frequent in type 2, and symptoms usually develop later without a gender preference. Hepatic encephalopathy and liver dysfunction are possible complications of both types and usually develop during adulthood. Both types are also associated with regenerative hepatic nodules. The clinical setting and imaging appearance of these nodules can help one avoid misdiagnosis. Definitive treatment of CEPS is determined by the type of shunt. Liver transplantation is the only effective treatment for symptomatic type 1 CEPS; surgical closure or embolization of the shunt is the therapeutic approach for type 2. Copyright © RSNA, 2011.

Congenital Shunts of the Portal Venous System: Case-series of Uncommon Shunts.

PubMed

Santos, Liliana; Nobre, Susana; Laezza, Nadia; Cunha, Catarina; Gonçalves, Isabel; Lopes, Maria F

Congenital shunts of the portal venous system are rare entities that can present in children with clinical heterogeneity. To evaluate the clinical course of children with uncommon shunts presenting to our institution and examine the available literature on this topic. Medical records of children with rare forms of congenital shunts were retrospectively reviewed for demographics, symptoms, management, and outcome between 2003 and 2016. Three female patients with congenital shunts, including a congenital mesenterico-portal Rex shunt (n = 1) and congenital portosystemic shunts (CPSS) (n = 2), were referred for surgical evaluation between ages 4 and 9. Median follow-up was 8 years (range, 6-13 years). One asymptomatic patient did not require treatment and remained disease-free during long-term follow-up. The other 2 patients with CPSS and unusual symptoms, including liver focal nodular hyperplasia (FNH) in infancy (n = 1) and bleeding from esophageal varices (n = 1), showed subsequent progression to liver nodules that were managed by endovascular shunt occlusion. One patient showed symptom resolution and the other showed stable lesions at last follow-up. Literature yielded descriptions of two cases of congenital mesenterico-portal Rex shunt, one case of coincident CPSS and FNH in infancy, but zero reports of bleeding from esophageal varices. This case series examines each distinct patient's presentation, discusses the diagnosis, management and outcome and compares findings while discussing literature on this topic. A high index of suspicion and familiarity with unusual forms and treatment options is required to allow timely diagnosis and appropriate treatment.

Increase in hepatic arterial blood flow after transjugular intrahepatic portosystemic shunt creation and its potential predictive value of postprocedural encephalopathy and mortality.

PubMed

Patel, N H; Sasadeusz, K J; Seshadri, R; Chalasani, N; Shah, H; Johnson, M S; Namyslowski, J; Moresco, K P; Trerotola, S O

2001-11-01

To determine (i) whether there is a significant increase in hepatic artery blood flow (HABF) after transjugular intrahepatic portosystemic shunt (TIPS) creation and (ii) whether the extent of incremental increase in HABF is predictive of clinical outcome after TIPS creation. Prospective, nonrandomized, nonblinded duplex Doppler ultrasound (US) examinations were performed on 24 consecutive patients (19 men; Child Class A/B/C: 4/12/8, respectively) with a mean age of 52.8 years who were referred for TIPS creation for variceal bleeding. Peak hepatic artery velocity and vessel dimensions were used to calculate the hepatic arterial blood flow (HABF) before and after TIPS creation. Patients were clinically followed in the gastrohepatology clinic and TIPS US surveillance was performed at 1 and 3 months to assess shunt function. The extent of incremental increase in HABF was analyzed as a predictor of post-TIPS encephalopathy and/or death. The technical success rate of TIPS creation was 100%. The shunt diameters were either 10 mm (n = 11) or 12 mm (n = 13). TIPS resulted in a significant reduction in the portosystemic gradient from 24.3 mm Hg +/- 5.7 to 9.3 mm Hg +/- 2.9 (P <.001). The hepatic artery peak systolic velocity and HABF increased significantly after TIPS creation, from 60.8 cm/sec +/- 26.7 to 121 cm/sec +/- 51.5 (P <.001) and from 254.2 mL/min +/- 142.2 to 507.8 mL/min +/- 261.3 (P <.001), respectively. The average incremental increase in HABF from pre-TIPS to post-TIPS was 253.6 mL/min +/- 174.2 and the average decremental decrease in portosystemic gradient was 15.0 mm Hg +/- 5.3, but there was no significant correlation (r = 0.04; P =.86) between the two. All shunts were patent at 30 and 90 days without sonographic evidence of shunt dysfunction. After TIPS creation, new or worsened encephalopathy developed in five patients at 30 days and in an additional three at 90 days. They were all successfully managed medically. Three patients (12.5%) died within 30 days

Hepatic hepcidin gene expression in dogs with a congenital portosystemic shunt.

PubMed

Frowde, P E; Gow, A G; Burton, C A; Powell, R; Lipscomb, V J; House, A K; Mellanby, R J; Tivers, M S

2014-01-01

Microcytic anemia is common in dogs with a congenital portosystemic shunt (cPSS) and typically resolves after surgical attenuation of the anomalous vessel. However, the pathophysiology of the microcytic anemia remains poorly understood. Hepcidin has been a key role in controlling iron transport in both humans and animals and in mediating anemia of inflammatory disease in humans. The role of hepcidin in the development of microcytic anemia in dogs with a cPSS has not been examined. To determine whether hepatic hepcidin mRNA expression decreases, while red blood cell count (RBC) and mean corpuscular volume (MCV) increase in dogs after surgical attenuation of a cPSS. Eighteen client-owned dogs with confirmed cPSS undergoing surgical attenuation. Prospective study. Red blood cell count (RBC) and mean corpuscular volume (MCV), together with hepatic gene expression of hepcidin, were measured in dogs before and after partial attenuation of a cPSS. There was a significant increase in both RBC (median pre 6.17 × 10(12) /L, median post 7.08 × 10(12) /L, P < .001) and MCV (median pre 61.5fl, median post 65.5fl, P = .006) after partial surgical attenuation of the cPSS. Despite the increase in both measured red blood cell parameters, hepatic gene expression of hepcidin remained unchanged. This study found no evidence that dysregulated production of hepcidin was associated with anemia in dogs with a cPSS. Copyright © 2014 by the American College of Veterinary Internal Medicine.

Visualization of hepatic arteries with 3D ultrasound during intra-arterial therapies

NASA Astrophysics Data System (ADS)

Gérard, Maxime; Tang, An; Badoual, Anaïs.; Michaud, François; Bigot, Alexandre; Soulez, Gilles; Kadoury, Samuel

2016-03-01

Liver cancer represents the second most common cause of cancer-related mortality worldwide. The prognosis is poor with an overall mortality of 95%. Moreover, most hepatic tumors are unresectable due to their advanced stage at discovery or poor underlying liver function. Tumor embolization by intra-arterial approaches is the current standard of care for advanced cases of hepatocellular carcinoma. These therapies rely on the fact that the blood supply of primary hepatic tumors is predominantly arterial. Feedback on blood flow velocities in the hepatic arteries is crucial to ensure maximal treatment efficacy on the targeted masses. Based on these velocities, the intra-arterial injection rate is modulated for optimal infusion of the chemotherapeutic drugs into the tumorous tissue. While Doppler ultrasound is a well-documented technique for the assessment of blood flow, 3D visualization of vascular anatomy with ultrasound remains challenging. In this paper we present an image-guidance pipeline that enables the localization of the hepatic arterial branches within a 3D ultrasound image of the liver. A diagnostic Magnetic resonance angiography (MRA) is first processed to automatically segment the hepatic arteries. A non-rigid registration method is then applied on the portal phase of the MRA volume with a 3D ultrasound to enable the visualization of the 3D mesh of the hepatic arteries in the Doppler images. To evaluate the performance of the proposed workflow, we present initial results from porcine models and patient images.

Hyperammonemia and Systemic Inflammatory Response Syndrome Predicts Presence of Hepatic Encephalopathy in Dogs with Congenital Portosystemic Shunts

PubMed Central

Tivers, Mickey S.; Handel, Ian; Gow, Adam G.; Lipscomb, Vicky J.; Jalan, Rajiv; Mellanby, Richard J.

2014-01-01

Hepatic encephalopathy (HE) is an important cause of morbidity and mortality in patients with liver disease. The pathogenesis of he is incompletely understood although ammonia and inflammatory cytokines have been implicated as key mediators. To facilitate further mechanistic understanding of the pathogenesis of HE, a large number of animal models have been developed which often involve the surgical creation of an anastomosis between the hepatic portal vein and the caudal vena cava. One of the most common congenital abnormalities in dogs is a congenital portosystemic shunt (cpss), which closely mimics these surgical experimental models of HE. Dogs with a cPSS often have clinical signs which mimic clinical signs observed in humans with HE. Our hypothesis is that the pathogenesis of HE in dogs with a cPSS is similar to humans with HE. The aim of the study was to measure a range of clinical, haematological and biochemical parameters, which have been linked to the development of HE in humans, in dogs with a cPSS and a known HE grade. One hundred and twenty dogs with a cPSS were included in the study and multiple regression analysis of clinical, haematological and biochemical variables revealed that plasma ammonia concentrations and systemic inflammatory response syndrome scores predicted the presence of HE. Our findings further support the notion that the pathogenesis of canine and human HE share many similarities and indicate that dogs with cPSS may be an informative spontaneous model of human HE. Further investigations on dogs with cPSS may allow studies on HE to be undertaken without creating surgical models of HE thereby allowing the number of large animals used in animal experimentation to be reduced. PMID:24392080

Hyperammonemia and systemic inflammatory response syndrome predicts presence of hepatic encephalopathy in dogs with congenital portosystemic shunts.

PubMed

Tivers, Mickey S; Handel, Ian; Gow, Adam G; Lipscomb, Vicky J; Jalan, Rajiv; Mellanby, Richard J

2014-01-01

Hepatic encephalopathy (HE) is an important cause of morbidity and mortality in patients with liver disease. The pathogenesis of he is incompletely understood although ammonia and inflammatory cytokines have been implicated as key mediators. To facilitate further mechanistic understanding of the pathogenesis of HE, a large number of animal models have been developed which often involve the surgical creation of an anastomosis between the hepatic portal vein and the caudal vena cava. One of the most common congenital abnormalities in dogs is a congenital portosystemic shunt (cpss), which closely mimics these surgical experimental models of HE. Dogs with a cPSS often have clinical signs which mimic clinical signs observed in humans with HE. Our hypothesis is that the pathogenesis of HE in dogs with a cPSS is similar to humans with HE. The aim of the study was to measure a range of clinical, haematological and biochemical parameters, which have been linked to the development of HE in humans, in dogs with a cPSS and a known HE grade. One hundred and twenty dogs with a cPSS were included in the study and multiple regression analysis of clinical, haematological and biochemical variables revealed that plasma ammonia concentrations and systemic inflammatory response syndrome scores predicted the presence of HE. Our findings further support the notion that the pathogenesis of canine and human HE share many similarities and indicate that dogs with cPSS may be an informative spontaneous model of human HE. Further investigations on dogs with cPSS may allow studies on HE to be undertaken without creating surgical models of HE thereby allowing the number of large animals used in animal experimentation to be reduced.

21 CFR 882.4545 - Shunt system implantation instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shunt system implantation instrument. 882.4545 Section 882.4545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4545 Shunt system...

21 CFR 882.4545 - Shunt system implantation instrument.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Shunt system implantation instrument. 882.4545 Section 882.4545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4545 Shunt system...

Congenital portosystemic shunts: diagnosis and treatment.

PubMed

Franchi-Abella, Stéphanie; Gonzales, Emmanuel; Ackermann, Oanez; Branchereau, Sophie; Pariente, Danièle; Guérin, Florent

2018-05-05

Congenital portosystemic shunts (CPSS) are rare vascular malformations that create an abnormal connection between portal and systemic veins resulting in complete or partial diversion of the portal flow away from the liver to the systemic venous system. Different anatomic types exist and several classifications have been proposed. They can be associated with other malformations especially cardiac and heterotaxia. The main complications include hepatic encephalopathy, liver tumors, portopulmonary hypertension, and pulmonary arteriovenous shunts. Diagnosis relies on imaging, and prenatal diagnosis is possible. Spontaneous closure of the CPSS is possible in some anatomic forms during the first year of life. When the CPSS remains patent, radiologic or surgical closure of the CPSS may prevent, resolve, or stabilize complications. Interventional radiology plays a key role for both the preoperative evaluation with occlusion test to assess the exact anatomy and to measure portal pressure after occlusion of the CPSS. Endovascular closure is the first option for treatment when possible.

Two cases of esophageal cancer with portal hypertension: esophagectomy with venous shunt procedure.

PubMed

Kato, T; Motohara, T; Kaneko, Y; Shikishima, H; Okushiba, S; Kondo, S; Kato, H

2001-01-01

We performed venous shunt procedure in the reconstruction of the esophagus after esophagectomy using the gastric tube in two cases of esophageal cancer with portal hypertension due to liver cirrhosis. In both cases, the short-term postoperative course was uneventful, without congestion in the gastric tube. In Case 1 where the short gastric vein had been used as the shunt vein, the long-term postoperative course was also uneventful, without hepatic encephalopathy or hemorrhage from deterioration of the varices of the gastric tube. However, in Case 2 where the left gastroepiploic vein had been used, hepatic encephalopathy developed due to excessive shunt flow. These results suggested that appropriate shunt flow could be expected by using short gastric vein.

Congenital extrahepatic portosystemic shunt complicated by the development of hepatocellular carcinoma.

PubMed

Sharma, Ruchi; Suddle, Abid; Quaglia, Alberto; Peddu, Praveen; Karani, John; Satyadas, Thomas; Heaton, Nigel

2015-10-01

Congenital extrahepatic portosystemic shunt, also known as Abernethy malformation, is a rare congenital malformation. It causes shunting of blood through a communication between the portal and systemic veins such as a patent ductus venous. We report 3 cases of Abernethy malformation complicated by the development of hepatocellular carcinoma. Additionally, we comprehensively reviewed all previously reported cases and highlighted common features that may help in early diagnosis and appropriate management. Patients with Abernethy malformation may have an increased propensity to develop hepatocellular carcinoma. All 5 previously reported cases, plus the three of our patients, have a type 1 (complete) shunt suggesting a role for absent portal blood flow in the pathogenesis of hepatocellular carcinoma. Congenital extrahepatic portosystemic shunt should be sought for in cases with raised serum ammonia, hepatic encephalopathy or hepatocellular carcinoma in the absence of cirrhosis.

Morphology of splenocaval congenital portosystemic shunts in dogs and cats.

PubMed

White, R N; Parry, A T

2016-01-01

To describe the anatomy of congenital portosystemic shunts involving the splenic vein communicating with the caudal vena cava at the level of the epiploic foramen. A retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. Ninety-eight dogs and eight cats met the inclusion criteria of a congenital portosystemic shunt involving the splenic vein communicating with the prehepatic caudal vena cava plus recorded intra-operative mesenteric portovenography or computed tomography angiography and gross observations at surgery. All cases (both dogs and cats) had a highly consistent shunt that involved a distended gastrosplenic vein that communicated with the caudal vena cava at the level of the epiploic foramen via an anomalous left gastric vein. The morphology of the shunt type described appeared to be a result of an abnormal communication between the left gastric vein and the caudal vena cava and the subsequent development of preferential blood flow through an essentially normal portal venous system. The abnormal communication (shunt) was through the left gastric vein and not the splenic vein, as might have been expected. This information may help with surgical planning in cases undergoing shunt closure surgery. © 2015 British Small Animal Veterinary Association.

Congenital intrahepatic portosystemic shunt--an incidental rare anomaly.

PubMed

Singh, Kunwarpal; Kapoor, Aprajita; Kapoor, Atul; Gupta, Kamini; Mahajan, Goldaa

2006-12-01

Congenital intrahepatic shunts are rare anomalies that are usually incidental in a child who undergoes an ultrasound examination for some other reasons. Early diagnosis is important, because the condition can lead to hepatic encephalopathy and hypoglycemia. Author's would like to describe the findings of one such patient diagnosed to be having congenital intrahepatic shunt and discuss the clinical importance of this condition.

Congenital multiple intrahepatic portosystemic shunt: an autopsy case

PubMed Central

Takahashi, Seishiro; Yoshida, Eriko; Sakanishi, Yasushi; Tohyama, Norihiro; Ayhan, Ayse; Ogawa, Hiroshi

2014-01-01

Multiple intrahepatic portosystemic shunt (IPSS) without portal hypertension, now thought to be congenital in origin, is very rare. The presence of IPSS, unlike other congenital diseases, may not be recognized for several decades due to the time it takes to develop hepatic encephalopathy. In this article, we report an autopsy case of an 80-year-old Japanese woman with a one-month history of hyperammonemic encephalopathy. Radiological examination of the liver revealed some abnormal connections between the branches of the portal veins and the hepatic veins, but the cause of the aberrant blood flow was not found. The cause of death was extensive cerebral infarction due to thromboembolism. At postmortem examination, multiple anomalous blood vessels were identified histologically in both lobes of the non-cirrhotic liver. In comparison with the few similar cases existing in the literature, this case should be diagnosed as congenital IPSS. To our knowledge, this is the first detailed histological study of IPSS, as several autopsy case reports exist but their histological descriptions are poor. Unlike past reports, the shunt vessels were accompanied by clear elastic lamellae that were microscopically observed. In addition to shunt vessels, septal fibrosis, disorder of hepatic acinar structure, and sinusoidal dilatation and capillarization were observed in the liver. We suggest that these histological modifications observed in the circumference of the shunt vessels acted as secondary regenerative/hyperplastic changes based on blood-flow imbalance caused by the IPSS. PMID:24427367

Congenital multiple intrahepatic portosystemic shunt: an autopsy case.

PubMed

Takahashi, Seishiro; Yoshida, Eriko; Sakanishi, Yasushi; Tohyama, Norihiro; Ayhan, Ayse; Ogawa, Hiroshi

2014-01-01

Multiple intrahepatic portosystemic shunt (IPSS) without portal hypertension, now thought to be congenital in origin, is very rare. The presence of IPSS, unlike other congenital diseases, may not be recognized for several decades due to the time it takes to develop hepatic encephalopathy. In this article, we report an autopsy case of an 80-year-old Japanese woman with a one-month history of hyperammonemic encephalopathy. Radiological examination of the liver revealed some abnormal connections between the branches of the portal veins and the hepatic veins, but the cause of the aberrant blood flow was not found. The cause of death was extensive cerebral infarction due to thromboembolism. At postmortem examination, multiple anomalous blood vessels were identified histologically in both lobes of the non-cirrhotic liver. In comparison with the few similar cases existing in the literature, this case should be diagnosed as congenital IPSS. To our knowledge, this is the first detailed histological study of IPSS, as several autopsy case reports exist but their histological descriptions are poor. Unlike past reports, the shunt vessels were accompanied by clear elastic lamellae that were microscopically observed. In addition to shunt vessels, septal fibrosis, disorder of hepatic acinar structure, and sinusoidal dilatation and capillarization were observed in the liver. We suggest that these histological modifications observed in the circumference of the shunt vessels acted as secondary regenerative/hyperplastic changes based on blood-flow imbalance caused by the IPSS.

Pathophysiological appraisal of a rat model of total hepatic ischemia with an extracorporeal portosystemic shunt.

PubMed

Suzuki, S; Nakamura, S; Sakaguchi, T; Mitsuoka, H; Tsuchiya, Y; Kojima, Y; Konno, H; Baba, S

1998-11-01

Animal models of total hepatic ischemia (THI) and reperfusion injury are restricted by concomitant splanchnic congestion. This study was performed to determine the requirement suitable for an extracorporeal portosystemic shunt (PSS) to maintain the intestinal integrity in a rat model of THI. Using a polyethylene tube (0.86 or 1 mm i.d.), PSS was placed between the mesenteric and jugular veins. Comparison was done between THI models with or without PSS and a partial ischemia model with hepatectomy of the nonischemic lobes. Well-tolerated hepatic ischemic period, portal pressure after 10 min of hepatic ischemia, portal endotoxin levels at 1 h after reperfusion, histological features of the small bowel just before reperfusion, and local jejunal and ileal blood hemoglobin oxygen saturation index (ISO2) were compared among the models. Animals without PSS poorly tolerated 30 min of THI. Animals receiving THI with PSS or partial hepatic ischemia tolerated a longer ischemic period (60 min) with a significantly higher small bowel ISO2, lower portal pressure and endotoxin levels (P < 0.01), and less histological damage of the small bowel when compared to those receiving THI without PSS. Portal endotoxin levels after THI with PSS using a 1-mm i.d. tube as well as partial hepatic ischemia were significantly lower than those after THI with PSS using a 0.86-mm i.d. tube. THI with PSS using a 1-mm i.d. tube was strikingly similar to partial hepatic ischemia in the pathophysiological profile during hepatic ischemia. PSS with a tube 1 mm or more in inner diameter offers pathophysiological advantages in experiments on THI and reperfusion. Copyright 1998 Academic Press.

Circulating Elastin Fragments Are Not Affected by Hepatic, Renal and Hemodynamic Changes, But Reflect Survival in Cirrhosis with TIPS.

PubMed

Nielsen, M J; Lehmann, J; Leeming, D J; Schierwagen, R; Klein, S; Jansen, C; Strassburg, C P; Bendtsen, F; Møller, S; Sauerbruch, T; Karsdal, M A; Krag, A; Trebicka, J

2015-11-01

Progressive fibrosis increases hepatic resistance and causes portal hypertension with complications. During progressive fibrosis remodeling and deposition of collagens and elastin occur. Elastin remodeling is crucially involved in fibrosis progression in animal models and human data. This study investigated the association of circulating elastin with the clinical outcome in cirrhotic patients with severe portal hypertension receiving transjugular intrahepatic porto-systemic shunt (TIPS). We analyzed portal and hepatic venous samples of 110 cirrhotic patients obtained at TIPS insertion and 2 weeks later. The circulating levels of elastin fragments (ELM) were determined using specific monoclonal ELISA. The relationship of ELM with clinical short-time follow-up and long-term outcome was investigated. Circulating levels of ELM showed a gradient across the liver before TIPS with higher levels in the hepatic vein. Interestingly, the circulating ELM levels remained unchanged after TIPS. The circulating levels of ELM in portal and hepatic veins correlated with platelet counts and inversely with serum sodium. Hepatic venous levels of ELM were higher in CHILD C compared to CHILD A and B and were associated with the presence of ascites. Patients with high levels of ELM in the hepatic veins before TIPS showed poorer survival. In multivariate analysis ELM levels in the hepatic veins and MELD were independent predictors of mortality in these patients. This study demonstrated that circulating levels of ELM are not associated with hemodynamic changes, but might reflect fibrosis remodeling and predict survival in patients with severe portal hypertension receiving TIPS independently of MELD.

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

PubMed

Wessel, David L; Berger, Felix; Li, Jennifer S; Dähnert, Ingo; Rakhit, Amit; Fontecave, Sylvie; Newburger, Jane W

2013-06-20

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 to the shunt. In a multicenter, double-blind, event-driven trial, we randomly assigned infants 92 days of age or younger with cyanotic congenital heart disease and a systemic-to-pulmonary-artery shunt to receive clopidogrel at a dose of 0.2 mg per kilogram of body weight per day (467 infants) 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 120 days of age. The rate of the composite primary end point did not differ significantly between the clopidogrel group (19.1%) and the placebo group (20.5%) (absolute risk difference, 1.4 percentage points; relative risk reduction with clopidogrel, 11.1%; 95% confidence interval, -19.2 to 33.6; P=0.43), nor did the rates of the three components of the composite primary end point. There was no significant benefit of clopidogrel treatment in any subgroup, including subgroups defined by shunt type. Clopidogrel recipients and placebo recipients had similar rates of overall bleeding (18.8% and 20.2%, respectively) and severe bleeding (4.1% and 3.4%, respectively). Clopidogrel therapy in infants with cyanotic congenital heart disease palliated with a systemic-to-pulmonary-artery shunt, most of whom received concomitant aspirin therapy, did not reduce either mortality from any cause or shunt-related morbidity. (Funded by Sanofi-Aventis and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00396877.).

Imaging and radiological interventions in extra-hepatic portal vein obstruction

PubMed Central

Pargewar, Sudheer S; Desai, Saloni N; Rajesh, S; Singh, Vaibhav P; Arora, Ankur; Mukund, Amar

2016-01-01

Extrahepatic portal vein obstruction (EHPVO) is a primary vascular condition characterized by chronic long standing blockage and cavernous transformation of portal vein with or without additional involvement of intrahepatic branches, splenic or superior mesenteric vein. Patients generally present in childhood with multiple episodes of variceal bleed and EHPVO is the predominant cause of paediatric portal hypertension (PHT) in developing countries. It is a pre-hepatic type of PHT in which liver functions and morphology are preserved till late. Characteristic imaging findings include multiple parabiliary venous collaterals which form to bypass the obstructed portal vein with resultant changes in biliary tree termed portal biliopathy or portal cavernoma cholangiopathy. Ultrasound with Doppler, computed tomography, magnetic resonance cholangiography and magnetic resonance portovenography are non-invasive techniques which can provide a comprehensive analysis of degree and extent of EHPVO, collaterals and bile duct abnormalities. These can also be used to assess in surgical planning as well screening for shunt patency in post-operative patients. The multitude of changes and complications seen in EHPVO can be addressed by various radiological interventional procedures. The myriad of symptoms arising secondary to vascular, biliary, visceral and neurocognitive changes in EHPVO can be managed by various radiological interventions like transjugular intra-hepatic portosystemic shunt, percutaneous transhepatic biliary drainage, partial splenic embolization, balloon occluded retrograde obliteration of portosystemic shunt (PSS) and revision of PSS. PMID:27358683

Evolution of congenital malformations of the umbilical-portal-hepatic venous system.

PubMed

Scalabre, Aurelien; Gorincour, Guillaume; Hery, Geraldine; Gamerre, Marc; Guys, Jean-Michel; de Lagausie, Pascal

2012-08-01

The objective of this study is to describe the evolution of 8 cases of congenital malformations of the umbilical-portal-hepatic venous system diagnosed before the first month of life. All cases of congenital malformation of the portal and hepatic venous system diagnosed prenatally or during the first month of life in our institution were systematically reviewed since November 2000. Clinical features, imaging, and anatomical findings were reviewed, focusing primarily on clinical and radiologic evolution. Eight cases of congenital malformation of the umbilical-portal-hepatic venous system were studied. Fifty percent of these malformations were diagnosed prenatally. We report 4 portosystemic shunts. Three involuted spontaneously, and the fourth one required surgical treatment. We report a variation of the usual anatomy of portal and hepatic veins that remained asymptomatic, an aneurysmal dilatation of a vitelline vein causing portal vein thrombosis that needed prompt surgical treatment with good result, a complex portal and hepatic venous malformation treated operatively, and a persistent right umbilical vein that remained asymptomatic. Prenatal diagnosis of malformations of the umbilical-portal-hepatic venous network is uncommon. Little is known about the postnatal prognosis. Clinical, biologic, and radiologic follow-up by ultrasonography is essential to distinguish pathologic situations from normal anatomical variants. Copyright © 2012 Elsevier Inc. All rights reserved.

Aberrant Gene Expression in Dogs with Portosystemic Shunts

PubMed Central

Grinwis, Guy C. M.; Kummeling, Anne; van Gils, Ingrid H. M.; Koerkamp, Marian J. A. Groot.; van Leenen, Dik; Holstege, Frank C. P.; Penning, Louis C.; Rothuizen, Jan; Leegwater, Peter A. J.; Spee, Bart

2013-01-01

Congenital portosystemic shunts are developmental anomalies of the splanchnic vascular system that cause portal blood to bypass the liver. Large-breed dogs are predisposed for intrahepatic portosystemic shunts (IHPSS) and small-breed dogs for extrahepatic portosystemic shunts (EHPSS). While the phenotype resulting from portal bypass of the liver of the two types of shunt is identical, the genotype and molecular pathways involved are probably different. The aim of this study was to gain insight into the pathways involved in the different types of portosystemic shunting. Microarray analysis of mRNA expression in liver tissue from dogs with EHPSS and IHPSS revealed that the expression of 26 genes was altered in either IHPSS or EHPSS samples compared with that in liver samples from control dogs. Quantitative real-time PCR of these genes in 14 IHPSS, 17 EHPSS, and 8 control liver samples revealed a significant differential expression of ACBP, CCBL1, GPC3, HAMP, PALLD, VCAM1, and WEE1. Immunohistochemistry and Western blotting confirmed an increased expression of VCAM1 in IHPSS but its absence in EHPSS, an increased WEE1 expression in IHPSS but not in EHPSS, and a decreased expression of CCBL1 in both shunt types. Regarding their physiologic functions, these findings may indicate a causative role for VCAM1 in IHPSS and WEE1 for IHPSS. CCBL1 could be an interesting candidate to study not yet elucidated aspects in the pathophysiology of hepatic encephalopathy. PMID:23451256

The Evolution of Transjugular Intrahepatic Portosystemic Shunt: Tips

PubMed Central

Fanelli, Fabrizio

2014-01-01

Since Richter's description in the literature in 1989 of the first procedure on human patients, transjugular intrahepatic portosystemic shunt (TIPS) has been worldwide considered as a noninvasive technique to manage portal hypertension complications. TIPS succeeds in lowering the hepatic sinusoidal pressure and in increasing the circulatory flow, thus reducing sodium retention, ascites recurrence, and variceal bleeding. Required several revisions of the shunt TIPS can be performed in case of different conditions such as hepatorenal syndrome, hepatichydrothorax, portal vein thrombosis, and Budd-Chiari syndrome. Most of the previous studies on TIPS procedure were based on the use of bare stents and most patients chose TIPS 2-3 years after traditional treatment, thus making TIPS appear to be not superior to endoscopy in survival rates. Bare stents were associated with higher incidence of shunt failure and consequently patients required several revisions during the follow-up. With the introduction of a dedicated e-PTFE covered stent-graft, these problems were completely solved, No more reinterventions are required with a tremendous improvement of patient's quality of life. One of the main drawbacks of the use of e-PTFE covered stent-graft is higher incidence of hepatic encephalopathy. In those cases refractory to the conventional medical therapy, a shunt reduction must be performed. PMID:27335841

Contrast enhanced computed tomography and reconstruction of hepatic vascular system for transjugular intrahepatic portal systemic shunt puncture path planning.

PubMed

Qin, Jian-Ping; Tang, Shan-Hong; Jiang, Ming-De; He, Qian-Wen; Chen, Hong-Bin; Yao, Xin; Zeng, Wei-Zheng; Gu, Ming

2015-08-28

To describe a method for the transjugular intrahepatic portal systemic shunt (TIPS) placement performed with the aid of contrast-enhanced computed tomography (CECT) and three-dimensional reconstructed vascular images (3D RVIs), and to assess its safety and effectiveness. Four hundred and ninety patients were treated with TIPS between January 2005 and December 2012. All patients underwent liver CECT and reconstruction of 3D RVIs of the right hepatic vein to portal vein (PV) prior to the operation. The 3D RVIs were carefully reviewed to plan the puncture path from the start to target points for needle pass through the PV in the TIPS procedure. The improved TIPS procedure was successful in 483 (98.6%) of the 490 patients. The number of punctures attempted was one in 294 (60%) patients, 2 to 3 in 147 (30%) patients, 4 to 6 in 25 (5.1%) patients and more than 6 in 17 (3.5%) patients. Seven patients failed. Of the 490 patients, 12 had punctures into the artery, 15 into the bile duct, eight into the gallbladder, and 18 through the liver capsule. Analysis of the portograms from the 483 successful cases indicated that the puncture points were all located distally to the PV bifurcation on anteroposterior images, while the points were located proximally to the bifurcation in the three cases with intraabdominal bleeding. The complications included three cases of bleeding, of whom one died and two needed surgery. Use of CECT and 3D RVIs to plan the puncture path for TIPS procedure is safe, simple and effective for clinical use.

[Congenital portosystemic shunt. The Abernethy malformation].

PubMed

Avila, L F; Luis, A L; Encinas, J L; Hernández, F; Olivares, P; Fernández Cuadrado, J; Hierro, L; Jara, P; López Santamaría, M; Tovar, J A

2006-10-01

Congenital portosystemic shunt (CEPS) is a rare condition that was first reported by John Abernethy in 1793. Two types of CEPS are described: type I (side to end anastomosis) or congenital absence of the portal vein, and type II (side to side anastomosis) with portal vein supply partially conserved. Type I CEPS is usually seen in girls and associates multiple malformations as polysplenia, malrotation, and cardiac anomalies. Type II is even rarer with no sex preference and no malformations associated. Hepatic encephalopathy is a common complication of both types in adulthood. Liver transplantation is the only effective treatment for symptomatic type I CEPS. A therapeutic approach for type II could be surgical closure of the shunt. To analyse our experience in diagnosis and management of portosystemic shunts. We report 4 cases of CEPS (3 type I and 1 type II) diagnosed between January-1997 and March-2005 in our department. We present 4 patients with ages at diagnosis ranging from 0 to 28 months, 3 type I CEPS (2 boys and 1 girl) and 1 boy type II. The type I girl was prenatally diagnosed at 12 weeks of gestation. Initial clinical signs in type 1 boys were splenomegaly and hypersplenism, both with normal pondo-statural growth. No polysplenia or cardiac anomalies were assessed. One of them presented mild developmental delay, dismorphic features and facial telangiectasias. He had normal coagulation tests with chronic hepatic dysfunction (high transaminases) and regenerative nodular lesions were seen by imaging techniques. The other type I patient had hypoprothrombinemia, tendency to capillary bleeding (haematomas and epistaxis) with preserved liver function. Both patients have developed mild portal hypertension and present steatosis signs at liver biopsy. The type I girl presents a 21 trisomy and associates a cardiac anomaly (interauricular communication). Her hepatic function test are normal but liver calcifications can be seen by ultrasound. Type II child associates

Markers of hepatic regeneration associated with surgical attenuation of congenital portosystemic shunts in dogs.

PubMed

Tivers, Michael S; Lipscomb, Victoria J; Smith, Kenneth C; Wheeler-Jones, Caroline P D; House, Arthur K

2014-05-01

Dogs with congenital portosystemic shunts (CPSS) have liver hypoplasia and hepatic insufficiency. Surgical CPSS attenuation results in liver growth associated with clinical improvement. The mechanism of this hepatic response is unknown, although liver regeneration is suspected. This study investigated whether markers of liver regeneration were associated with CPSS attenuation. Dogs treated with CPSS attenuation were prospectively recruited. Residual liver tissue was collected for gene expression analysis (seven genes) from 24 CPSS dogs that tolerated complete attenuation, 25 dogs that tolerated partial attenuation and seven control dogs. Relative gene expression was measured using quantitative polymerase chain reaction (qPCR). Blood samples were collected before, 24 h and 48 h post-surgery from 36 CPSS dogs and from 10 control dogs. Serum hepatocyte growth factor (HGF) concentration was measured using a canine specific enzyme-linked immunosorbent assay (ELISA). HGF mRNA expression was significantly decreased in CPSS compared with control dogs (P = 0.046). There were significant increases in HGF (P = 0.050) and methionine adenosyltransferase 2 A (MAT2A; P = 0.002) mRNA expression following partial CPSS attenuation. Dogs with complete attenuation had significantly greater MAT2A (P = 0.024) mRNA expression compared with dogs with partial attenuation. Serum HGF concentration significantly increased 24 h following CPSS attenuation (P < 0.001). Hepatic mRNA expression of two markers of hepatocyte proliferation (HGF and MAT2A) was associated with the response to surgery in dogs with CPSS, and serum HGF significantly increased following surgery, suggesting hepatocyte proliferation. These findings support the concept that hepatic regeneration is important in the hepatic response to CPSS surgery. Copyright © 2014 Elsevier Ltd. All rights reserved.

l-Arginine Pathway Metabolites Predict Need for Intra-operative Shunt During Carotid Endarterectomy.

PubMed

Szabo, P; Lantos, J; Nagy, L; Keki, S; Volgyi, E; Menyhei, G; Illes, Z; Molnar, T

2016-12-01

Asymmetric dimethylarginine (ADMA) inhibits nitric oxide (NO) synthesis and is a marker of atherosclerosis. This study examined the correlation between pre-operative l-arginine and ADMA concentration during carotid endarterectomy (CEA), and jugular lactate indicating anaerobic cerebral metabolism, jugular S100B reflecting blood-brain barrier integrity, and with factors of surgical intervention. The concentration of l-arginine, ADMA, and symmetric dimethylarginine was measured in blood taken under regional anaesthesia from the radial artery of 55 patients prior to CEA. Blood gas parameters, concentration of lactate, and S100B were also serially measured in blood taken from both the radial artery and the jugular bulb before and after carotid clamping, and after release of the clamp. To estimate anaerobic metabolism, the jugulo-arterial ratio of CO 2 gap/oxygen extraction was calculated. Positive correlation was found between pre-operative ADMA levels and the ratio of jugulo-arterial CO 2 gap/oxygen extraction during clamp and reperfusion (p = .005 and p = .01, respectively). An inverse correlation was found between the pre-operative l-arginine concentration and jugular lactate at each time point (both p = .002). The critical pre-operative level of l-arginine was determined by receiver operator curve analysis. If l-arginine was below the cutoff value of 35 μmol/L, jugular S100B concentration was higher 24 h post-operatively (p = .03), and jugular lactate levels were increased during reperfusion (p = .02). The median pre-operative concentration of l-arginine was lower in patients requiring an intra-operative shunt than in patients without need of shunt (median: 30.3 μmol/L [interquartile range 24.4-34.4 μmol/L] vs. 57.6 μmol/L [interquartile range 42.3-74.5 μmol/L]; p = .002). High pre-operative ADMA concentration predicts poor cerebral perfusion indicated by elevated jugulo-arterial CO 2 gap/oxygen extraction. Low pre-operative l

Design trade-offs among shunt current, pumping loss and compactness in the piping system of a multi-stack vanadium flow battery

NASA Astrophysics Data System (ADS)

Ye, Qiang; Hu, Jing; Cheng, Ping; Ma, Zhiqi

2015-11-01

Trade-off between shunt current loss and pumping loss is a major challenge in the design of the electrolyte piping network in a flow battery system. It is generally recognized that longer and thinner ducts are beneficial to reduce shunt current but detrimental to minimize pumping power. Base on the developed analog circuit model and the flow network model, we make case studies of multi-stack vanadium flow battery piping systems and demonstrate that both shunt current and electrolyte flow resistance can be simultaneously minimized by using longer and thicker ducts in the piping network. However, extremely long and/or thick ducts lead to a bulky system and may be prohibited by the stack structure. Accordingly, the intrinsic design trade-off is between system efficiency and compactness. Since multi-stack configurations bring both flexibility and complexity to the design process, we perform systematic comparisons among representative piping system designs to illustrate the complicated trade-offs among numerous parameters including stack number, intra-stack channel resistance and inter-stack pipe resistance. As the final design depends on various technical and economical requirements, this paper aims to provide guidelines rather than solutions for designers to locate the optimal trade-off points according to their specific cases.

Portosystemic shunts for extrahepatic portal hypertension in children.

PubMed

Tocornal, J; Cruz, F

1981-07-01

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

Congenital intrahepatic portosystemic shunt diagnosed during intrauterine life.

PubMed

Bellettini, Camila Vieira; Wagner, Rafaela; Sette Balzanelo, Aleocídio; de Souza Andretta, André Luis; Nascimento de Moura, Arthur; Fabris, Catia Carolina; Maranhão Gubert, Eduardo

2016-09-01

To report a patient with prenatal diagnosis of portosystemic shunt; a rare condition in humans. 17-day-old female infant admitted for investigation of suspected diagnosis of portosystemic shunt, presumed in obstetric ultrasound. The hypothesis was confirmed after abdominal angiography and liver Doppler. Other tests such as echocardiography and electroencephalogram were performed to investigate possible co-morbidities or associated complications, and were normal. We chose conservative shunt treatment, as there were no disease-related complications and this was intrahepatic shunt, which could close spontaneously by the age of 2 years. Portosystemic shunt can lead to various complications such as hepatic encephalopathy, hypergalactosemia, liver tumors, and hepatopulmonary syndrome. Most diagnoses are done after one month of age, after such complications occur. The prenatal diagnosis of this patient provided greater security for the clinical picture management, as well as regular monitoring, which allows the anticipation of possible complications and perform interventional procedures when needed. Copyright © 2016. Publicado por Elsevier Editora Ltda.

Congenital intrahepatic portosystemic shunt diagnosed during intrauterine life

PubMed Central

Bellettini, Camila Vieira; Wagner, Rafaela; Balzanelo, Aleocídio Sette; Andretta, André Luis de Souza; de Moura, Arthur Nascimento; Fabris, Catia Carolina; Gubert, Eduardo Maranhão

2016-01-01

Abstract Objective: To report a patient with prenatal diagnosis of portosystemic shunt; a rare condition in humans. Case description: 17-Day-old female infant admitted for investigation of suspected diagnosis of portosystemic shunt, presumed in obstetric ultrasound. The hypothesis was confirmed after abdominal angiography and liver Doppler. Other tests such as echocardiography and electroencephalogram were performed to investigate possible co-morbidities or associated complications, and were normal. We chose conservative shunt treatment, as there were no disease-related complications and this was intrahepatic shunt, which could close spontaneously by the age of 2 years. Comments: Portosystemic shunt can lead to various complications such as hepatic encephalopathy, hypergalactosemia, liver tumors, and hepatopulmonary syndrome. Most diagnoses are done after one month of age, after such complications occur. The prenatal diagnosis of this patient provided greater security for the clinical picture management, as well as regular monitoring, which allows the anticipation of possible complications and perform interventional procedures when needed. PMID:27133713

Congenital intrahepatic portosystemic shunts: Imaging findings and endovascular management

PubMed Central

Chandrasekharan, Rajsekar; Pullara, Sreekumar K; Thomas, Tixon; Kader, Nazar Puthukudiyil; Moorthy, Srikanth

2016-01-01

We present two cases of congenital intrahepatic portosystemic shunts in which the right portal vein directly communicated with the inferior venacava (IVC) in one patient and with the hepatic vein in the other. Multiple hepatic nodules consistent with focal nodular hyperplasia (FNH) were seen in the first patient. The second patient presented with recurrent history of hepatic encephalopathy. Percutaneous transhepatic embolization was performed using coils and Amplatz device following which she completely recovered. PMID:27081230

21 CFR 882.5550 - Central nervous system fluid shunt and components.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Central nervous system fluid shunt and components... Central nervous system fluid shunt and components. (a) Identification. A central nervous system fluid... central nervous system to an internal delivery site or an external receptacle for the purpose of relieving...

21 CFR 882.5550 - Central nervous system fluid shunt and components.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Central nervous system fluid shunt and components... Central nervous system fluid shunt and components. (a) Identification. A central nervous system fluid... central nervous system to an internal delivery site or an external receptacle for the purpose of relieving...

21 CFR 882.5550 - Central nervous system fluid shunt and components.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Central nervous system fluid shunt and components... Central nervous system fluid shunt and components. (a) Identification. A central nervous system fluid... central nervous system to an internal delivery site or an external receptacle for the purpose of relieving...

21 CFR 882.5550 - Central nervous system fluid shunt and components.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Central nervous system fluid shunt and components... Central nervous system fluid shunt and components. (a) Identification. A central nervous system fluid... central nervous system to an internal delivery site or an external receptacle for the purpose of relieving...

21 CFR 882.5550 - Central nervous system fluid shunt and components.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Central nervous system fluid shunt and components... Central nervous system fluid shunt and components. (a) Identification. A central nervous system fluid... central nervous system to an internal delivery site or an external receptacle for the purpose of relieving...

Serum hyaluronic acid in dogs with congenital portosystemic shunts.

PubMed

Seki, M; Asano, K; Sakai, M; Kanno, N; Teshima, K; Edamura, K; Tanaka, S

2010-05-01

To compare the serum level of hyaluronic acid in dogs with congenital portosystemic shunt with that in healthy dogs and to investigate the perioperative change in serum hyaluronic acid following shunt attenuation. Blood samples were obtained from 29 congenital portosystemic shunt dogs before the operation, and 2 and 4 weeks after the operation from 17 and 7 dogs, respectively. The serum hyaluronic acid level of these dogs was measured and compared with that of 10 healthy beagles. The median preoperative hyaluronic acid level in dogs with congenital portosystemic shunt was significantly elevated compared with that in healthy dogs. Furthermore, the median postoperative hyaluronic acid level significantly decreased compared with the median preoperative levels in congenital portosystemic shunt dogs. In the case of dogs with congenital portosystemic shunt, the reduction of intrahepatic portal blood flow might lower the clearance rate of hyaluronic acid in hepatic sinusoidal endothelial cells, so hyaluronic acid clearance could be improved by attenuation of a shunt vessel. Hence, serum hyaluronic acid levels might be useful to evaluate liver function and also have the potential to evaluate successful attenuation of a shunt vessel in dogs with congenital portosystemic shunt. Further investigations are required to clarify whether serum hyaluronic acid offers significant benefits over existing markers such as serum bile acid or ammonia concentrations.

Management of idiopathic intracranial hypertension with a programmable lumboperitoneal shunt: Early experience.

PubMed

Alkherayf, Fahad; Abou Al-Shaar, Hussam; Awad, Michael

2015-09-01

To evaluate the clinical outcomes and complications rate among idiopathic intracranial hypertension (IIH) patients who underwent lumboperitoneal (LP) shunt insertion with a programmable Strata valve. We retrospectively evaluated patients who underwent LP shunt with a programmable Strata valve insertion at the University of Ottawa Civic Hospital from November 2012 to June 2013. The demographic data, clinical symptoms, opening pressure, pre-operative and post-operative visual fields, neuroimaging, visual acuity, disc status, and complications were recorded and analyzed. Seven female patients with IIH underwent insertion of an LP shunt with a programmable Strata valve. The mean opening pressure was 35.8 cm H2O. The initial valve setting was 1.5, and four patients required post-operative valve pressure adjustment. All patients showed significant improvement in objective visual testing at follow-up as well as less frequent headaches. None of the patients developed intra- or post-operative complications. LP shunts with programmable Strata valve systems are a potential alternative to conventional LP and programmable ventriculoperitoneal shunt systems as well as optic nerve sheath fenestration, due to their potential in avoiding brain injury, lower failure and complication rates, lower intracranial hypotension incidence, and flexibility in adjusting valve pressure settings post-operatively evading under- and overdrainage complications. They should be considered for the management of IIH instead of early design LP systems and VP shunts. A randomized multi-center trial should be conducted to compare the efficacy of these surgical techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

Ovarian hyperstimulation syndrome leading to ventriculoperitoneal shunt malfunction: Case report.

PubMed

Azriel, Amit; Fleming, Benjamin; Dior, Uri P; Moscovici, Samuel; Sufaro, Yuval; Awad, Mohammed; Drummond, Kate

2018-06-01

Ventriculoperitoneal shunt (VPS) insertion is a common neurosurgical procedure for hydrocephalus. Unfortunately, VPS malfunction is not uncommon, with an estimated cumulative rate of 32% at 5 years. As flow through the shunt is influenced by the pressure gradient between the ventricles and the peritoneal cavity, malfunction may be caused by elevated intra-abdominal pressure. We present a rare patient with ascites following ovarian hyperstimulation syndrome (OHSS) leading to shunt malfunction. OHSS is a potentially life-threatening complication of controlled ovarian stimulation caused by the administration of exogenous gonadotropins. In this patient clinical and radiological resolution of shunt dysfunction were achieved following peritoneocentesis. To our knowledge this is the first described case of OHSS leading to shunt malfunction, emphasizing the importance of awareness, early recognition and proper management of abdominal etiologies of VPS malfunction. Copyright © 2018 Elsevier Ltd. All rights reserved.

What are the implications of the spontaneous spleno-renal shunts in liver cirrhosis?

PubMed Central

2009-01-01

Background Although significant advances are expected to be made in the assessment of the portal hypertension-related complications, the prognostic role of spleno-renal shunts has not been fully explored so far. Clarifying this aspect could help tackle the life-treating events occurring in patients suffering from liver cirrhosis. The aim of the study was to analyze the relationships between the spleno-renal shunts presence at doppler ultrasound and the liver cirrhosis complications. Methods Design: eighty one patients out of 129 formed the study population (35 females). Chronic liver damage in these patients was caused by HCV (66), HBV (2), alcohol abuse (2) or unknown etiology, likely non-alcoholic steatohepatitis (11). Setting: two Liver Units of university/primary hospitals in Southern Italy. Main outcome measures: grading of esofageal varices; detection of ascites: assessment of hepatic encephalopathy; evaluation of liver cirrhosis severity; tracking hepatocellular carcinoma; doppler features of spleno-renal shunts and splenic flow velocity; spleen longitudinal diameter at sonography. Results The prevalence of spleno-renal shunts was 18.5%, without no difference concerning the etiology (HCV versus non-HCV, p = 0.870); the prevalence of hepatocellular carcinoma in patients with spleno-renal shunts was superior to that of patients without them (Pearson Chi-square, p = 0.006, power of sample size 74%), also after adjustment for liver decompensation (p = 0.024). The median score of hepatic encephalopathy in patients with and without spleno-renal shunts was similar, i.e., 0 (range, 0-2) versus 0 (0 - 3), p = 0.67. The median splenic vein flow velocity in patients with spleno-renal shunts was significantly inferior to that of patients without them, i.e., 13 cm/sec (95% confidence intervals, 6-18) versus 21 cm/sec (17-24), p < 0.0001. By far the largest percentage of large esophageal varices was in patients without spleno-renal shunts (p = 0.005). In contrast, the

The long-term prognosis of congenital portosystemic venous shunt.

PubMed

Uchino, T; Matsuda, I; Endo, F

1999-08-01

Congenital portosystemic venous shunt (PSVS), considered to be a rare disease, can lead to hepatic encephalopathy (HE). With improvements in diagnostic imaging techniques, the number of infants and children with documented PSVS has increased. The natural course of the disease and indications for surgical closure of the shunt vessel have not been well defined. We reviewed 51 cases of congenital PSVS in Japan; 34 patients had an intrahepatic PSVS, and 17 had an extrahepatic PSVS. There were 12 patients with HE at the time of diagnosis. The frequency of HE increased in subjects over 60 years of age. Children with HE had a shunt ratio exceeding 60%. When the shunt ratio was less than 30%, HE did not occur. Twenty of 28 patients under the age of 15 years had hypergalactosemia at the time of neonatal screening. Part of the congenital intrahepatic PSVS spontaneously closed. Surgical closure of a PSVS may be an approach expected to prevent HE when the shunt ratio exceeds 60%.

Recovery of hepatic clearance and extraction following a release of common bile duct obstruction in the rat.

PubMed

Melzer, E; Krepel, Z; Ronen, I; Bar-Meir, S

1992-01-01

The rate of recovery for hepatic clearance and extraction following release of common-duct obstruction was investigated in the rat. Male Wistar rats underwent ligation of a cannulated common bile duct. Two weeks later, the cannula was opened and implanted into the duodenum, thus re-establishing enterohepatic circulation. Hepatic extraction and indocyanine green clearance were determined in three groups of six rats each, which differed by the time elapsed from the re-establishment of communication between the common bile duct and duodenum, i.e., 1, 48 and 168 h, respectively. A fourth group, in which a sham operation was performed, served as a control. Clearance was reduced from 16.9 +/- 2.5 ml/min per kg in the control group to 2.9 +/- 0.8, 5.4 +/- 2.4, and 8.5 +/- 3.3 ml/min per kg 1, 48, and 168 h, respectively, after release of common-bile-duct obstruction. Extraction rate was reduced from 37.3 +/- 5.9% to 17.5 +/- 2.7% in the 1st hour and recovered completely at 1 week. Thus, in the rat, release of a 2-week common-bile-duct obstruction is associated with complete recovery of the extraction capacity of the liver within a week, but only incomplete recovery of clearance. This decrease in clearance seems to be due to a decrease in effective hepatic blood flow, mostly probably due to the development of porto-systemic shunts.

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

PubMed

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

2014-02-01

To evaluate outcomes of systemic to pulmonary artery shunts (SPS) in patients weighing less than 3 kg with regard to shunt type, shunt size, and surgical approach. Patients weighing less than 3 kg who underwent modified Blalock-Taussig or central shunts with polytetrafluoroethylene grafts at our institution from January 1, 2000, to May 31, 2011, were reviewed. Patients who had undergone other major concomitant procedures were excluded from the analysis. Primary outcomes included mortality (discharge mortality and mortality before next planned palliative procedure or definitive repair), cardiac arrest and/or extracorporeal membrane oxygenation (ECMO), and shunt reintervention. In this cohort of 80 patients, discharge survival was 96% (77/80). Postoperative cardiac arrest or ECMO occurred in 6/80 (7.5%), and shunt reintervention was required in 14/80 (17%). On univariate analysis, shunt reintervention was more common in patients with 3-mm shunts (11/30, 37%) compared with 3.5-mm (2/36, 6%) or 4-mm shunts (1/14, 7%) (P < .003). There were no statistically significant associations between shunt type, shunt size, or surgical approach and cardiac arrest/ECMO or mortality. Multiple logistic regression demonstrated that a shunt size of 3 mm (P = .019) and extracardiac anomaly (P = .047) were associated with shunt reintervention, whereas no variable was associated with cardiac arrest/ECMO or mortality. In this high-risk group of neonates weighing less than 3 kg at the time of SPS, survival to discharge and the next planned surgical procedure was high. Outcomes were good with the 3.5- and 4-mm shunts; however, shunt reintervention was common with 3-mm shunts. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Inherited liver shunts in dogs elucidate pathways regulating embryonic development and clinical disorders of the portal vein.

PubMed

van Steenbeek, Frank G; van den Bossche, Lindsay; Leegwater, Peter A J; Rothuizen, Jan

2012-02-01

Congenital disorders of the hepatic portal vasculature are rare in man but occur frequently in certain dog breeds. In dogs, there are two main subtypes: intrahepatic portosystemic shunts, which are considered to stem from defective closure of the embryonic ductus venosus, and extrahepatic shunts, which connect the splanchnic vascular system with the vena cava or vena azygos. Both subtypes result in nearly complete bypass of the liver by the portal blood flow. In both subtypes the development of the smaller branches of the portal vein tree in the liver is impaired and terminal branches delivering portal blood to the liver lobules are often lacking. The clinical signs are due to poor liver growth, development, and function. Patency of the ductus venosus seems to be a digenic trait in Irish wolfhounds, whereas Cairn terriers with extrahepatic portosystemic shunts display a more complex inheritance. The genes involved in these disorders cannot be identified with the sporadic human cases, but in dogs, the genome-wide study of the extrahepatic form is at an advanced stage. The canine disease may lead to the identification of novel genes and pathways cooperating in growth and development of the hepatic portal vein tree. The same pathways likely regulate the development of the vascular system of regenerating livers during liver diseases such as hepatitis and cirrhosis. Therefore, the identification of these molecular pathways may provide a basis for future proregenerative intervention.

Congenital portosystemic shunts in children: a new anatomical classification correlated with surgical strategy.

PubMed

Blanc, Thomas; Guerin, Florent; Franchi-Abella, Stéphanie; Jacquemin, Emmanuel; Pariente, Danièle; Soubrane, Olivier; Branchereau, Sophie; Gauthier, Frédéric

2014-07-01

To propose an anatomical classification of congenital portosystemic shunts (CPSs) correlating with conservative surgery. CPSs entail a risk of life-threatening complications because of poor portal inflow, which may be prevented or cured by their closure. Current classifications based on portal origin of the shunt are not helpful for planning conservative surgery. Twenty-three patients who underwent at least 1 surgical procedure to close the CPSs were included in this retrospective study (1997-2012). We designed a classification according to the ending of the shunt in the caval system. We analyzed the results and outcomes of surgery according to this classification. Two patients had an extrahepatic portosystemic shunt, 17 had a portacaval shunt [subdivided in 5 end-to-side-like portal-caval, 7 side-to-side-like portal-caval, and 5 H-shaped (H-type portal-caval)], 2 had portal-to-hepatic vein shunts (portohepatic), and 2 had a persistent ductus venosus. All extrahepatic portosystemic shunts, H-type portal-caval, portohepatic, and patent ductus venosus patients had a successful 1-stage ligation. All 5 end-to-side-like portal-caval patients had a threadlike intrahepatic portal venous system; a 2-stage complete closure was successfully achieved for 4 and a partial closure for 1. The first 2 side-to-side-like portal-caval patients had a successful 2-stage closure whereas the 5 others had a 1-stage longitudinal caval partition. All patients are alive and none needed a liver transplantation. Our classification correlates the anatomy of CPSs and the surgical strategy: outcomes are good provided end-to-side-like portal-caval shunts patients have a 2-stage closure, side-to-side portal-caval shunts patients have a 1-stage caval partition, and the others have a 1-stage ligation.

Mesocaval Shunt Creation for Jejunal Variceal Bleeding with Chronic Portal Vein Thrombosis.

PubMed

Yoon, Ja Kyung; Kim, Man Deuk; Lee, Do Yun; Han, Seok Joo

2018-01-01

The creation of transjugular intrahepatic portosystemic shunt (TIPS) is a widely performed technique to relieve portal hypertension, and to manage recurrent variceal bleeding and refractory ascites in patients where medical and/or endoscopic treatments have failed. However, portosystemic shunt creation can be challenging in the presence of chronic portal vein occlusion. In this case report, we describe a minimally invasive endovascular mesocaval shunt creation with transsplenic approach for the management of recurrent variceal bleeding in a portal hypertension patient with intra- and extrahepatic portal vein occlusion. © Copyright: Yonsei University College of Medicine 2018.

Hepatoblastoma in Children With Congenital Portosystemic Shunts.

PubMed

Lautz, Timothy B; Shah, Sonam A; Superina, Riccardo A

2016-04-01

Two children developed hepatoblastoma concurrent with congenital portosystemic shunts (PSSs) (Abernethy malformations). Both underwent operative ligation of their PSSs. One received concurrent tumor resection, whereas the other was deemed initially unresectable and underwent biopsy followed by neoadjuvant chemotherapy. Although benign hepatic masses, such as focal nodular hyperplasia and nodular regenerative hyperplasia, are common in patients with Abernethy malformations, malignant tumors have also been documented and should always be considered in the differential diagnosis of a patient with a congenital PSS and a hepatic mass.

Shunt regulation electric power system

NASA Technical Reports Server (NTRS)

Wright, W. H.; Bless, J. J. (Inventor)

1971-01-01

A regulated electric power system having load and return bus lines is described. A plurality of solar cells interconnected in a power supplying relationship and having a power shunt tap point electrically spaced from the bus lines is provided. A power dissipator is connected to the shunt tap point and provides for a controllable dissipation of excess energy supplied by the solar cells. A dissipation driver is coupled to the power dissipator and controls its conductance and dissipation and is also connected to the solar cells in a power taping relationship to derive operating power therefrom. An error signal generator is coupled to the load bus and to a reference signal generator to provide an error output signal which is representative of the difference between the electric parameters existing at the load bus and the reference signal generator. An error amplifier is coupled to the error signal generator and the dissipation driver to provide the driver with controlling signals.

Endocannabinoids in liver disease and hepatic encephalopathy.

PubMed

Magen, Iddo; Avraham, Yosefa; Berry, Elliot; Mechoulam, Raphael

2008-01-01

Chronic liver disease results from a variety of causes such as hepatitis virus infections, autoimmune processes and alcohol consumption. Its complications include fat deposition, hemodynamic changes and fibrosis. Clinically there may be progression to portal-hypertension and porto-systemic encephalopathy. Pioneering research from the laboratory of Kunos at NIH has stressed the importance of endocannabinoids (ECs) as mediators of some of the pathological processes in chronic liver disease. The present review summarizes the literature on the association between ECs and liver disease, as well as the therapeutic potential of ECs and exogenous cannabinoids in liver disease with emphasis on hepatic encephalopathy.

Congenital Portosystemic Shunts: Clinic Heterogeneity Requires an Individual Management of the Patient.

PubMed

Chocarro, Gloria; Amesty, María Virginia; Encinas, Jose Luis; Vilanova Sánchez, Alejandra; Hernandez, Francisco; Andres, Ane M; Gamez, Manolo; Tovar, Juan Antonio; Lopez Santamaria, Manuel

2016-02-01

Congenital portosystemic shunt (CPSS) is a rare entity without insufficiency in treatment issues. The aim of this article is to show our experience in the heterogeneity of this condition. A retrospective study of 25 CPSS in the period 1995 to 2014 was conducted. Description of the morphology, clinical impact, and treatment is given. According to the imaging techniques (IT), the shunt was apparently intrahepatic in 14 patients, extrahepatic in 10 patients, and mixed in 1 patient. In 14 children, IT showed hepatic portal circulation. In total shunts in which radiological examination was performed, invasive radiological techniques were able to demonstrate intrahepatic portal vein. In other patients, it was not investigated as they are asymptomatic. A child presented multiorgan failure with fulminant hepatic failure at birth. The shunt was radiologically closed and clinical impairment reversed rapidly. He is now asymptomatic with no longer images of CPSS in ultrasound scan controls. Also, seven children are asymptomatic at this time and are monitored periodically. Seven children had prenatal diagnosis, in five the shunt closed spontaneously. Nine children were symptomatic in their evolution (hyperammonemia, regenerative nodules, cholestasis, gastrointestinal bleeding). Of these, in five we performed balloon test occlusion, tolerated in all patients, followed by radiological closure. In our experience, the advancement of interventional radiology techniques avoided surgery to close the shunt. Morphologically, the CPSS is extremely heterogeneous, with multiple possible connections established. CPSS has multiple clinical presentations, from asymptomatic patients to acute liver failure. The therapeutic approach should be individualized and therefore held in overspecialized centers. Georg Thieme Verlag KG Stuttgart · New York.

Hepatocyte transplants improve liver function and encephalopathy in portacaval shunted rats.

PubMed

Fogel, Wieslawa Agnieszka; Stasiak, Anna; Maksymowicz, Michał; Kobos, Jozef; Unzeta, Mercedes; Mussur, Miroslaw

2014-07-01

Rats with portacaval shunt (PCS) are useful experimental models of human hepatic encephalopathy in chronic liver dysfunction. We have previously shown that PCS modifies amine neurotransmitter systems in the CNS and increases voluntary alcohol intake by rats. Hepatocyte transplantation, used in acute liver failure, has recently also been applied to chronic liver diseases, which prompted us to investigate whether the altered brain amine system and the drinking behavior in long-term shunted rats could be normalized by hepatocyte transplants. Hepatocytes, isolated from syngeneic donors by collagenase digestion, were injected (3 × 10(6) cells/rat) into the pancreatic tail region, 6 months after PCS. Hepatic function was evaluated by measuring urine urea and plasma L-histidine concentrations. A free choice test with two bottles (tap water and 10% ethyl alcohol) was performed for 3 days to assess the rats' preference for alcohol. The rats were euthanized 2 months posttransplantation. Brain histamine and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured by radioenzymatic assay and by HPLC-EC, respectively, N-tele-methylhistamine by GC/MS while MAOA and MAOB activities by isotopic procedures. Portacaval shunt rats with hepatocyte transplants gave more urea than before transplantation, with lower plasma L-His levels and higher body weight versus the PCS counterparts. Also, those rats consumed less alcohol. The CNS amines and 5-HIAA concentrations, as well as MAO-B activity, being abnormally high in untreated PCS rats, significantly reduced after PCS hepatocyte treatment. The results support the therapeutic values of hepatocyte transplants in chronic liver diseases and the temporary character of PCS-exerted CNS dysfunctions. © 2014 John Wiley & Sons Ltd.

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

PubMed

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

2002-07-01

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

Oral glutamine challenge and magnetic resonance spectroscopy in three patients with congenital portosystemic shunts.

PubMed

Ortiz, María; Córdoba, Juan; Alonso, Juli; Rovira, Alex; Quiroga, Sergi; Jacas, Carlos; Esteban, Rafael; Guardia, Jaume

2004-03-01

Congenital portosystemic shunts are rare abnormalities of liver vasculature that can cause neurological symptoms, probably secondarily to the effects of the metabolism of ammonia in the brain. Our aim was to investigate the relationship between capillary blood ammonia after oral glutamine challenge and magnetic resonance spectroscopy in three patients with congenital portosystemic shunts. Neuropsychological tests, oral glutamine challenge and magnetic resonance spectroscopy were performed at baseline and after 6 months of follow-up in three patients with congenital portosystemic shunts. The results were compared to those obtained in a group of six cirrhotic patients with prior episodes of hepatic encephalopathy and healthy controls. Patients with congenital portosystemic shunts exhibited abnormalities of neuropsychological tests, magnetic resonance spectroscopy and a response to the oral glutamine challenge similar to those observed in patients with cirrhosis. The intensity of the rise of brain glutamine was correlated to the area under the curve of ammonia after the oral glutamine challenge (R=0.72). Neurological manifestations of patients with congenital portosystemic shunts are mediated through similar mechanisms that are involved in the pathogenesis of hepatic encephalopathy. The area under the curve appears to be the better parameter that defines the response to the oral glutamine challenge.

Management of Transjugular Intrahepatic Portosystemic Shunt (TIPS)-associated Refractory Hepatic Encephalopathy by Shunt Reduction Using the Parallel Technique: Outcomes of a Retrospective Case Series

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cookson, Daniel T., E-mail: danielthomascookson@yahoo.co.uk; Zaman, Zubayr; Gordon-Smith, James

2011-02-15

Purpose: To investigate the reproducibility and technical and clinical success of the parallel technique of transjugular intrahepatic portosystemic shunt (TIPS) reduction in the management of refractory hepatic encephalopathy (HE). Materials and Methods: A 10-mm-diameter self-expanding stent graft and a 5-6-mm-diameter balloon-expandable stent were placed in parallel inside the existing TIPS in 8 patients via a dual unilateral transjugular approach. Changes in portosystemic pressure gradient and HE grade were used as primary end points. Results: TIPS reduction was technically successful in all patients. Mean {+-} standard deviation portosystemic pressure gradient before and after shunt reduction was 4.9 {+-} 3.6 mmHg (range,more » 0-12 mmHg) and 10.5 {+-} 3.9 mmHg (range, 6-18 mmHg). Duration of follow-up was 137 {+-} 117.8 days (range, 18-326 days). Clinical improvement of HE occurred in 5 patients (62.5%) with resolution of HE in 4 patients (50%). Single episodes of recurrent gastrointestinal hemorrhage occurred in 3 patients (37.5%). These were self-limiting in 2 cases and successfully managed in 1 case by correction of coagulopathy and blood transfusion. Two of these patients (25%) died, one each of renal failure and hepatorenal failure. Conclusion: The parallel technique of TIPS reduction is reproducible and has a high technical success rate. A dual unilateral transjugular approach is advantageous when performing this procedure. The parallel technique allows repeat bidirectional TIPS adjustment and may be of significant clinical benefit in the management of refractory HE.« less

[Selective portal-systemic shunts for bleeding portal hypertension].

PubMed

Orozco, H; Mercado, M A; Takahashi, T; García-Tsao, G; Guevara, L; Hernandez-Ortiz, J; Tielve, M

1990-07-01

At the beginning of the seventies, we began to perform regularly selective shunts for the treatment of portal hypertension. In a 15 year period, 177 patients (155 with liver cirrhosis) were operated with three kinds of selective shunts: 128 with a Warren shunt, 29 with an end to end renosplenic shunt and 20 with a splenocaval shunt. 167 cases were operated in an elective fashion. The 15 years global operative mortality, was 14.4%. Operative mortality of the Child A patients, was 11.6%. Survival for the Child A group was 74.6% at 1 year, 68.2% at 5 years and 64.6% at 15 years. Incapacitating encephalopathy was observed in 6.9%, rebleeding 6.2% and shunt thrombosis in 6.2%. Portal vein alterations in the postoperative period were observed: in 13.3% a reduction in diameter ocurred and in 20.5%, thrombosis was recorded. It is concluded that when feasible, the selective shunts are the treatment of choice for portal hypertension in those patients with good liver function.

Study on the Automatic Detection Method and System of Multifunctional Hydrocephalus Shunt

NASA Astrophysics Data System (ADS)

Sun, Xuan; Wang, Guangzhen; Dong, Quancheng; Li, Yuzhong

2017-07-01

Aiming to the difficulty of micro pressure detection and the difficulty of micro flow control in the testing process of hydrocephalus shunt, the principle of the shunt performance detection was analyzed.In this study, the author analyzed the principle of several items of shunt performance detection,and used advanced micro pressure sensor and micro flow peristaltic pump to overcome the micro pressure detection and micro flow control technology.At the same time,This study also puted many common experimental projects integrated, and successfully developed the automatic detection system for a shunt performance detection function, to achieve a test with high precision, high efficiency and automation.

Establishing a preoperative evaluation system for lumboperitoneal shunt: Approach to attenuate the risk of shunt failure.

PubMed

Sun, Tong; Yuan, Yikai; Zhang, Qiuming; Zhou, Yicheng; Li, Xuepei; Yu, Hang; Tian, Meng; Guan, Junwen

2018-06-12

Lumboperitoneal shunt (LPS) has been demonstrated an effective method for the treatment of communicating hydrocephalus in the presence of frequent shunt failure. To determine if establishing a preoperative evaluation system could benefit patients thus attenuating the risk of LPS failure. In this three-year study, treated by LPS, patients undergoing preoperative evaluation were included into study group and others without preoperative evaluation were included into control group. Perioperative conditions, including Keifer's hydrocephalus score (KHS), symptomatic control rate (SCR), Evans index, complications, long-term shunt revision rate, and quality of life (QOL), were synchronously investigated. 93 eligible patients were included in the study (study group: 51, control group: 42). The baseline characteristics of two groups were basically similar. The results showed patients in study group had better short-term improvement in symptoms and imageology, including higher SCR (Median, 62.5% vs 50%, P=0.001), more reduction in Evans index (0.08±0.05 vs 0.05±0.04, P=0.002), and lower incidence of postoperative complications (Median, 35.3% vs 57.1%, P=0.04). Similarly, the incidence of shunt revision in study group was dramatically lower than control group (Median, 15.7% vs 40.9%, P=0.006) in line with the revision-free curve (P=0.002), in which suggested most of patients received revision, if needed, within 3 months. Additionally, patients in study group had better QOL. In conclusion, patients who underwent the evaluation before LPS had better short-term and long-term outcomes, suggesting it would be a promising strategy to correctly select patients for LPS with prolonged favorable shunt outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

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

PubMed

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

2016-10-01

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

Validation of EncephalApp, Smartphone-based Stroop Test, for the Diagnosis of Covert Hepatic Encephalopathy

PubMed Central

Bajaj, Jasmohan S; Heuman, Douglas M; Sterling, Richard K; Sanyal, Arun J; Siddiqui, Muhammad; Matherly, Scott; Luketic, Velimir; Stravitz, R Todd; Fuchs, Michael; Thacker, Leroy R; Gilles, HoChong; White, Melanie B; Unser, Ariel; Hovermale, James; Gavis, Edith; Noble, Nicole A; Wade, James B

2014-01-01

Background & Aims Detection of covert hepatic encephalopathy (CHE) is difficult but point of care testing could increase rates of diagnosis. We aimed to validate the ability of the smartphone app EncephalApp, a streamlined version of Stroop App, to detect CHE. We evaluated face validity, test–retest reliability, and external validity. Methods Patients with cirrhosis (n=167; 38% with overt HE [OHE]; mean age, 55 years; mean model for end-stage liver disease score, 12) and controls (n=114) were each given a paper and pencil cognitive battery (standard) along with EncephalApp. EncephalApp has Off and On states; results measured were: OffTime, OnTime, OffTime+OnTime, and number of runs required to complete 5 off and on runs. Thirty-six patients with cirrhosis underwent driving simulation tests, and EncephalApp results were correlated with results. Test–retest reliability was analyzed in a subgroup of patients. The test was performed before and after transjugular intra-hepatic portosystemic shunt placement, before and after correction for hyponatremia, to determine external validity. Results All patients with cirrhosis performed worse on paper and pencil and EncephalApp tests than controls. Patients with cirrhosis and OHE performed worse than those without OHE. Age-dependent EncephalApp cut-offs (younger or older than 45 years) were set. An OffTime+OnTime value of >190 seconds identified all patients with CHE with an area under the receiver operator characteristic (AUROC) value of 0.91; the AUROC value was 0.88 for diagnosis of CHE in those without OHE. EncephalApp times correlated with crashes and illegal turns in driving simulation tests. Test–retest reliability was high (intra-class coefficient, 0.83) among 30 patients retested 1–3 months apart. OffTime+OnTime increased significantly (206 vs 255, P=.007) among 10 patients retested 33±7 days after transjugular intra-hepatic portosystemic shunt placement. OffTime+OnTime decreased significantly (242 vs 225, P

Intra-Hepatic Depletion of Mucosal-Associated Invariant T Cells in Hepatitis C Virus-Induced Liver Inflammation.

PubMed

Bolte, Fabian J; O'Keefe, Ashley C; Webb, Lauren M; Serti, Elisavet; Rivera, Elenita; Liang, T Jake; Ghany, Marc; Rehermann, Barbara

2017-11-01

Chronic hepatitis affects phenotypes of innate and adaptive immune cells. Mucosal-associated invariant T (MAIT) cells are enriched in the liver as compared with the blood, respond to intra-hepatic cytokines, and (via the semi-invariant T-cell receptor) to bacteria translocated from the gut. Little is known about the role of MAIT cells in livers of patients with chronic hepatitis C virus (HCV) infection and their fate after antiviral therapy. We collected blood samples from 42 patients with chronic HCV infection who achieved a sustained virologic response after 12 weeks of treatment with sofosbuvir and velpatasvir. Mononuclear cells were isolated from blood before treatment, at weeks 4 and 12 during treatment, and 24 weeks after the end of treatment. Liver biopsies were collected from 37 of the patients prior to and at week 4 of treatment. Mononuclear cells from 56 blood donors and 10 livers that were not suitable for transplantation were used as controls. Liver samples were assessed histologically for inflammation and fibrosis. Mononuclear cells from liver and blood were studied by flow cytometry and analyzed for responses to cytokine and bacterial stimulation. The frequency of MAIT cells among T cells was significantly lower in blood and liver samples of patients with HCV infection than of controls (median, 1.31% vs 2.32% for blood samples, P = .0048; and median, 4.34% vs 13.40% for liver samples, P = .001). There was an inverse correlation between the frequency of MAIT cells in the liver and histologically determined levels of liver inflammation (r = -.5437, P = .0006) and fibrosis (r = -.5829, P = .0002). MAIT cells from the liver had higher levels of activation and cytotoxicity than MAIT cells from blood (P < .0001). Production of interferon gamma by MAIT cells was dependent on monocyte-derived interleukin 18, and was reduced in patients with HCV infection in response to T-cell receptor-mediated but not cytokine-mediated stimulation, as compared with

[Normal pressure hydrocephalus: prognostic value of height in patients treated with an identical shunt system].

PubMed

Aguas, Jesús; Rodrigo, Victor; Estupiñan, Francisco; Nogues, Pere; Villalba, Gloria; Villagrasa, Javier; Caral, Luis

2013-01-01

Normal pressure hydrocephalus (NPH) is a clinical entity frequently managed by means of a cerebrospinal fluid shunt. Hydrodynamic hypotheses consider hydrostatic pressure (as well as height) a very important variable for shunt system function. However, we did not find empirical studies supporting the influence of height on clinical response in the literature. Our objective was to study the prognostic value of height, as a variable related to hydrostatic pressure, when an identical shunt system is used. A prospective series of 61 idiopathic NPH cases was analyzed. All cases were shunted by means of a ventricle-peritoneal system with a 100mmH2O opening pressure valve. Anthropometric, clinical, radiological and pressure variables were registered, as well as delay for treatment, improvement and complications. 78.7% of cases improved after shunting. This group of patients was significantly taller (P=.005) than the group without response (median value 165cm versus 152cm). There was also a significant correlation between height and ventricular size decrease after the shunt. In our series opening valve pressure was a constant (100mmHg) and we could consequently focus on the effect of hydrostatic pressure (height). Moreover, we found a positive predictive value for taller patients, probably because we had selected an opening pressure especially suitable for them. Current gravitational valve shunt systems also recommend considering patient height when customising the system. Our study empirically supports this idea. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

The classification based on intrahepatic portal system for congenital portosystemic shunts.

PubMed

Kanazawa, Hiroyuki; Nosaka, Shunsuke; Miyazaki, Osamu; Sakamoto, Seisuke; Fukuda, Akinari; Shigeta, Takanobu; Nakazawa, Atsuko; Kasahara, Mureo

2015-04-01

Liver transplantation was previously indicated as a curative operation for congenital absence of portal vein. Recent advances in radiological interventional techniques can precisely visualize the architecture of the intrahepatic portal system (IHPS). Therefore, the therapeutic approach for congenital portosystemic shunt (CPS) needs to be reevaluated from a viewpoint of radiological appearances. The aim of this study was to propose the IHPS classification which could explain the pathophysiological characteristics and play a complementary role of a therapeutic approach and management for CPS. Nineteen patients with CPS were retrospectively reviewed. The median age at diagnosis was 6.8 years old. Eighteen of these patients underwent angiography with a shunt occlusion test and were classified based of the severity of the hypoplasia of IHPS. The eighteen cases who could undergo the shunt occlusion test were classified into mild (n=7), moderate (n=6) and severe types (n=5) according to the IHPS classification. The IHPS classification correlated with the portal venous pressure under shunt occlusion, the histopathological findings, postoperative portal venous flow and liver regeneration. Shunt closure resulted in dramatic improvement in the laboratory data and subclinical encephalopathy. Two patients with the severe type suffered from sepsis associated with portal hypertension after treatment, and from the portal flow steal phenomenon because of the development of unexpected collateral vessels. The patients with the severe type had a high risk of postoperative complications after shunt closure in one step, even if the PVP was relatively low during the shunt occlusion test. The IHPS could be visualized by the shunt occlusion test. The IHPS classification reflected the clinicopathological features of CPS, and was useful to determine the therapeutic approach and management for CPS. Copyright © 2015 Elsevier Inc. All rights reserved.

[The use of labelled albumin microspheres in the study of arteriovenous shunting in varicosities of the lower limbs (author's transl)].

PubMed

Serise, J M; Le Héron, D; Le Héron, G; Bonnet, A; Busquet, J; Basse-Cathalinat, B; Tingaud, R

1982-01-01

The greater proportion of oxygen in the blood circulating in veins of the lower limbs bought to attention the possibility of pre-capillary arteriovenous shunting. The intra-arteriel injection of Technetium labelled serum albumin microspheres enables one to quantify arteriovenous shunts greater than 25 microns. The authors made a comparative study of arterio-venous shunting by blood gases analysis and isotopic techniques in twenty patients. The results seem to deny the existence of arteriovenous shunts in the genesis of essential varicose veins in the lower limb.

The design and implementation of on-line monitoring system for UHV compact shunt capacitors

NASA Astrophysics Data System (ADS)

Tao, Weiliang; Ni, Xuefeng; Lin, Hao; Jiang, Shengbao

2017-08-01

Because of the large capacity and compact structure of the UHV compact shunt capacitor, it is difficult to take effective measures to detect and prevent the faults. If the fault capacitor fails to take timely maintenance, it will pose a threat to the safe operation of the system and the life safety of the maintenance personnel. The development of UHV compact shunt capacitor on-line monitoring system can detect and record the on-line operation information of UHV compact shunt capacitors, analyze and evaluate the early fault warning signs, find out the fault capacitor or the capacitor with fault symptom, to ensure safe and reliable operation of the system.

Use of intraoperative mesenteric portovenography in congenital portosystemic shunt surgery.

PubMed

White, Robert N; Macdonald, Nicholas J; Burton, Carolyn A

2003-01-01

A retrospective study of the use of intraoperative mesenteric portovenography (IOMP) in the surgical management of congenital portosystemic shunts in 100 dogs and cats was performed. Each portovenogram was scored using a subjective visual analogue scale (VAS) and was assessed for the presence of portal atresia or hypoplasia. VAS scores and portal hypoplasia assessments were obtained for portovenogram images obtained for each animal both before shunt manipulation (preligation) and following the temporary, complete ligation of the vessel (postligation). In each patient, surgical records were reviewed to ascertain the degree of shunt attenuation that was achieved at surgery. Hepatic portal vasculature was significantly different on postligation compared with preligation IOMP. Sixty-two percent of animals had apparent portal hypoplasia or atresia on their preligation IOMP. The majority of these (81%) had an improvement in portal vasculature on postligation IOMP. It was concluded that both preligation and postligation IOMP provided valuable information regarding the morphology of congenital portosystemic shunts. An accurate assessment of an animal's portal vasculature could only be made following the interpretation of a postligation portovenogram, and these findings significantly influenced the surgical management of the patient. Although individuals with high postligation VAS scores were more likely to achieve full shunt attenuation at surgery, there was no quantifiable relationship between IOMP findings and the degree of shunt attenuation achieved.

Predictors and outcomes of shunt-dependent hydrocephalus in patients with aneurysmal sub-arachnoid hemorrhage

PubMed Central

2012-01-01

Background Hydrocephalus following spontaneous aneurysmal sub-arachnoid hemorrhage (SAH) is often associated with unfavorable outcome. This study aimed to determine the potential risk factors and outcomes of shunt-dependent hydrocephalus in aneurysmal SAH patients but without hydrocephalus upon arrival at the hospital. Methods One hundred and sixty-eight aneurysmal SAH patients were evaluated. Using functional scores, those without hydrocephalus upon arrival at the hospital were compared to those already with hydrocephalus on admission, those who developed it during hospitalization, and those who did not develop it throughout their hospital stay. The Glasgow Coma Score, modified Fisher SAH grade, and World Federation of Neurosurgical Societies grade were determined at the emergency room. Therapeutic outcomes immediately after discharge and 18 months after were assessed using the Glasgow Outcome Score. Results Hydrocephalus accounted for 61.9% (104/168) of all episodes, including 82 with initial hydrocephalus on admission and 22 with subsequent hydrocephalus. Both the presence of intra-ventricular hemorrhage on admission and post-operative intra-cerebral hemorrhage were independently associated with shunt-dependent hydrocephalus in patients without hydrocephalus on admission. After a minimum 1.5 years of follow-up, the mean Glasgow outcome score was 3.33 ± 1.40 for patients with shunt-dependent hydrocephalus and 4.21 ± 1.19 for those without. Conclusions The presence of intra-ventricular hemorrhage, lower mean Glasgow Coma Scale score, and higher mean scores of the modified Fisher SAH and World Federation of Neurosurgical grading on admission imply risk of shunt-dependent hydrocephalus in patients without initial hydrocephalus. These patients have worse short- and long-term outcomes and longer hospitalization. PMID:22765765

Congenital portosystemic venous shunt.

PubMed

Papamichail, M; Pizanias, M; Heaton, N

2018-03-01

Congenital portosystemic venous shunts are rare developmental anomalies resulting in diversion of portal flow to the systemic circulation and have been divided into extra- and intrahepatic shunts. They occur during liver and systemic venous vascular embryogenesis and are associated with other congenital abnormalities. They carry a higher risk of benign and malignant liver tumors and, if left untreated, can result in significant medical complications including systemic encephalopathy and pulmonary hypertension. This article reviews the various types of congenital portosystemic shunts and their anatomy, pathogenesis, symptomatology, and timing and options of treatment. What is Known: • The natural history and basic management of this rare congenital anomaly are presented. What is New: • This paper is a comprehensive review; highlights important topics in pathogenesis, clinical symptomatology, and treatment options; and proposes an algorithm in the management of congenital portosystemic shunt disease in order to provide a clear idea to a pediatrician. An effort has been made to emphasize the indications for treatment in the children population and link to the adult group by discussing the consequences of lack of treatment or delayed diagnosis.

Shunt attachment and method for interfacing current collection systems

DOEpatents

Denney, P.E.; Iyer, N.C.; Hannan, W.F. III.

1992-12-08

A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature. 6 figs.

Shunt attachment and method for interfacing current collection systems

DOEpatents

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

1992-01-01

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

Congenital veno-venous malformations of the liver: widely variable clinical presentations.

PubMed

Witters, Peter; Maleux, Geert; George, Christophe; Delcroix, Marion; Hoffman, Ilse; Gewillig, Marc; Verslype, Chris; Monbaliu, Diethard; Aerts, Raymond; Pirenne, Jacques; Van Steenbergen, Werner; Nevens, Frederik; Fevery, Johan; Cassiman, David

2008-08-01

Congenital portosystemic veno-venous malformations are rare abnomalities that often remain undiagnosed. Typically they are classified by their anatomical characteristics according to Morgan (extrahepatic, Abernethy malformations type Ia,b and II) and Park (intrahepatic, types 1-4). However, their clinical presentation is less dependent on the anatomical type. We reviewed the clinical characteristics of six cases drawn from our files (from 1970 to 2006). One patient, a 25-year-old male, had extrahepatic shunting whereby the liver receives only arterial blood because the portal vein (PV) connects with the inferior caval vein (ICV) (Abernethy Ib); he presented with episodes of jaundice and pruritus. Three patients had extrahepatic shunting with patent intrahepatic portal veins, but with shunting of splenomesenterial blood towards the ICV (Abernethy II); these included a 66-year-old male with hepatic encephalopathy, a 17-year-old female with (porto?-)pulmonary hypertension without portal hypertension, and a 33-year-old female with epidsodes of acute pain secondary to spontaneous bleeding within a primary liver tumor. Two patients had intrahepatic shunting; these included an 8-year-old boy who was diagnosed incidentally during work-up for abnormal liver enzymes with a communication between right PV and ICV (Park type 1), and a 59-year-old male with multiple PV-ICV-shunts in several liver segments (Park, type 4) who presented with hepatic encephalopathy. Patients often present with signs of hepatic shunting (encephalopathy, pulmonary hypertension, hepatopulmonary syndrome, and/or hypoglycemia) with relative sparing of the synthetic liver function in the absence of portal hypertension. Some shunts present with space-occupying lesions (focal nodular hyperplasia, hepatocellular carcinoma, nodular regenerative hyperplasia, etc.) or biliary atresia. Finally, some cases are detected incidentally.

[Acute hepatic vascular complications].

PubMed

Ochs, A

2011-07-01

Acute hepatic vascular complications are rare. Acute portal vein thrombosis (PVT) and the Budd-Chiari syndrome (BSC) are the leading causes. Coagulopathy and local factors are present in up to 80% of cases. Diagnosis is established by colour-coded Doppler sonography, contrast-enhanced computed tomography or magnetic resonance imaging. Patients with acute PVT present with abdominal pain and disturbed intestinal motility. In the absence of cirrhosis anticoagulation with heparin is established followed by oral anticoagulation. In severe cases, surgical thrombectomy or transjugular thrombolysis with stent shunt may be necessary. Acute or fulminant BCS may require emergency liver transplantation or a transjugular intrahepatic portosystemic stent shunt, if patients present with acute liver failure. Milder cases receive anticoagulation for thrombolysis of occluded hepatic veins. Sinusoidal obstruction syndrome (SOS) is diagnosed after total body irradiation or chemotherapy, the term SOS replacing the former veno-occlusive disease. The treatment of congenital vascular malformations, complications in the setting of OLTX as well as patients with hepatic involvement of hereditary hemorrhagic telangiectasia requires significant expertise in a multidisciplinary approach.

Abernethy malformation: a case report

PubMed Central

2012-01-01

Background Abernethy malformation is a very rare congenital vascular malformation defined by diversion of portal blood away from liver. It is commonly associated with multiple congenital anomalies. We present a case of Abernethy malformation, without associated congenital anomalies from India. Case presentation A 5-year-old female child presented with short history of jaundice. A provisional diagnosis of acute viral hepatitis was made in view of clinical presentation and local endemicity of viral hepatitis A. Persistence of jaundice on follow up after 4 weeks led to detailed investigations. Ultrasound and doppler study of abdomen revealed drainage of portal vein into inferior vena cava. CT angiography was performed which confirmed the diagnosis of Type 1 b Abernethy malformation without associated major anomalies. We discuss the common clinical presentations, associated anomalies, diagnostic workup and treatment options of this disorder. Conclusion The treatment of the patients with congenital porto-systemic shunts depends on the site of the shunt, associated congenital anomalies and the extent of liver damage but the prognosis depends on the complications irrespective of anatomical type. However, the extent of associated abnormalities should not deter paediatricians to refer patients for treatment. Whenever possible closure of the shunt should be advised for cure or to prevent complications. Only symptomatic type I patients with absence of possibility to close the shunt may require liver transplant. Long-term follow-up is indicated for all patients. PMID:22642663

A rare congenital extrahepatic portosystemic shunt affecting the inferior mesenteric vein, inferior vena cava, and left ovarian vein.

PubMed

Takeuchi, Hajime; Takeda, Yoko; Takahashi, Miyo; Hayashi, Shogo; Fukuzawa, Yoshitaka; Nakano, Takashi

2014-09-01

To observe a case of congenital extrahepatic portosystemic shunt and discuss it from the embryological and clinical viewpoints. An 85-year-old female cadaver was employed for a dissection course at Aichi Medical University in 2009. There was no evidence of liver cirrhosis macroscopically or microscopically. A portosystemic shunt was observed that involved communication between the inferior mesenteric vein, inferior vena cava (IVC), and left ovarian vein by a single Y-shaped shunt vessel. To the best of our knowledge, this is the first reported case of the above-mentioned three veins being connected by a single Y-shaped shunt vessel. Considering the other venous diameters, the shunt appeared to flow into the splenic vein and IVC. It cannot be denied that this shunt may have led to hepatic encephalopathy, although the shunt effect may have been minimal. Embryological development of IVC appears to occur close to the plexus of anastomosing vitelline veins, forming the portal vein.

Long term results of balloon-occluded retrograde transvenous obliteration for portosystemic shunt encephalopathy in patients with liver cirrhosis and portal hypertension.

PubMed

Inoue, Hiroto; Emori, Keigo; Toyonaga, Atsushi; Oho, Kazuhiko; Kumamoto, Masafumi; Haruta, Tsuyoshi; Mitsuyama, Keiichi; Tsuruta, Osamu; Sata, Michio

2014-01-01

This study examined 19 patients with portosystemic shunt encephalopathy caused by a splenorenal shunt (SRS), which was treated with balloon-occluded retrograde transvenous obliteration (B-RTO). Long-term treatment outcomes were evaluated based on hepatic functional reserve and vital prognosis. Encephalopathy improved in all patients after shunt embolization and closure. Albumin, serum ammonia, and the Child-Pugh score, a measure of liver function, were significantly improved 3 years after B-RTO, and exacerbation of damage to liver function was avoided (p<0.01). During the follow-up period, three patients died from liver failure and two patients from hepatocellular carcinoma. Patients had a poor prognosis if their albumin levels were less than 2.8 mg / dL before B-RTO (p<0.05). Encephalopathy patients had complete response to B-RTO, but long-term prognosis was affected by hepatic functional reserve before B-RTO and by concurrent hepatocellular carcinoma. The results of this study suggest that in patients with SRS, it is important to perform B-RTO at an early stage when the hepatic functional reserve is still satisfactory.

Multiple acquired portosystemic shunts secondary to primary hypoplasia of the portal vein in a cat.

PubMed

Sugimoto, Satoko; Maeda, Shingo; Tsuboi, Masaya; Saeki, Kohei; Chambers, James K; Yonezawa, Tomohiro; Fukushima, Kenjiro; Fujiwara, Reina; Uchida, Kazuyuki; Tsujimoto, Hajime; Matsuki, Naoaki; Ohno, Koichi

2018-06-06

A 6-year 5-month-old spayed female Scottish Fold cat presented with a one-month history of gait abnormalities, increased salivation, and decreased activity. A blood test showed hyperammonemia and increased serum bile acids. Imaging tests revealed multiple shunt vessels indicating acquired portosystemic shunt. Histopathologic analysis of liver biopsy showed features consistent with liver hypoperfusion, such as a barely recognizable portal vein, increased numbers of small arterioles, and diffuse vacuolar degeneration of hepatocytes. These findings supported the diagnosis of primary hypoplasia of the portal vein/microvascular dysplasia, (PHPV/MVD). To our knowledge, this is the first case of feline PHPV/MVD that developed multiple acquired portosystemic shunts and presented with hepatic encephalopathy.

Ventriculoperitoneal shunt - discharge

MedlinePlus

... ventriculoperitoneal - discharge; VP shunt - discharge; Shunt revision - discharge; Hydrocephalus shunt placement - discharge ... Your child has hydrocephalus and needed a shunt placed to drain excess fluid and relieve pressure in the brain. This buildup of brain ...

Intra-Arterial Hepatic Chemotherapy: A Comparison of Percutaneous Versus Surgical Implantation of Port-Catheters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deschamps, F., E-mail: frederic.deschamps@igr.fr; Elias, D., E-mail: elias@igr.fr; Goere, D., E-mail: goere@igr.fr

2011-10-15

Purpose: To compare retrospectively the safety and efficacy of percutaneous and surgical implantations of port-catheters for intra-arterial hepatic chemotherapy (IAHC). Materials and Methods: Between January 2004 and December 2008, 126 consecutive patients (mean age 58 years) suffering from liver colorectal metastases were referred for intra-arterial hepatic chemotherapy (IAHC). Port-catheters were percutaneously implanted (P) through femoral access with the patient under conscious sedation when no other surgery was planned or were surgically implanted (S) when laparotomy was performed for another purpose. We report the implantation success rate, primary functionality, functionality after revision, and complications of IAHC. Results: The success rates ofmore » implantation were 97% (n = 65 of 67) for P and 98% (n = 58 of 59) for S. One hundred eleven patients received IAHC in our institution (n = 56P and n = 55S). Primary functionality was the same for P and S (4.80 vs. 4.82 courses), but functionality after revision was significantly higher for P (9.18 vs. 5.95 courses, p = 0.004) than for S. Forty-five complications occurred during 516 courses for P and 28 complications occurred during 331 courses for S. The rates of discontinuation of IAHC linked to complications of the port-catheters were 21% (n = 12 of 56) for P and 34% (n = 19 of 55) for S. Conclusion: Overall, significantly better functionality and similar complication rates occurred after P versus S port-catheters.« less

Ultrasound-guided transhepatic puncture of the hepatic veins for TIPS placement.

PubMed

Gazzera, C; Fonio, P; Gallesio, C; Camerano, F; Doriguzzi Breatta, A; Righi, D; Veltri, A; Gandini, G

2013-04-01

This retrospective analysis was carried out to assess the feasibility and results of transjugular intrahepatic portal systemic shunt (TIPS) performed with ultrasound (US)-guided percutaneous puncture of the hepatic veins. Over a period of 3 years, 153 patients were treated with TIPS at our centre. In eight cases, a percutaneous puncture of the middle (n=7) or right (n=1) hepatic vein was required because the hepatic vein ostium was not accessible. Indications for TIPS were bleeding (n=1), Budd-Chiari syndrome (n=1), ascites (n=2), reduced portal flow (n=1) and incomplete portal thrombosis (n=3). A 0.018-in. guidewire was anterogradely introduced into the hepatic vein to the inferior vena cava (IVC) through a 21-gauge needle. In the meantime, a 25-mm snare-loop catheter was introduced through the jugular access to retrieve the guidewire, achieving through-andthrough access. Then, a Rosch-Uchida set was used to place the TIPS with the traditional technique. Technical success was achieved in all patients. There was one case of stent thrombosis. One patient died of pulmonary oedema. Three patients were eligible for liver transplantation, whereas the others were excluded due to shunt thrombosis (n=1) and previous nonhepatic neoplasms (n=3). The percutaneous approach to hepatic veins is rapid and safe and may be useful for avoiding traumatic liver injuries.

Distal splenorenal shunt (DSS) in children: analysis of the first 21 consecutive cases.

PubMed Central

Maksoud, J G; Mies, S

1982-01-01

Twenty-one children from the ages of 4 to 12 years old were treated for esophageal hemorrhage by distal splenorenal shunt (DSS). In four patients, thrombosis of the shunt occurred within the first 24 hours after operation. In the other 17 children, long-term shunt patency was verified. Only one thrombosis has occurred in the last 15 consecutive cases. The patients were followed from one-half to six years. Late angiographic studies were performed in five patients. Forward flow through the portal vein was demonstrated in all patients. In addition, collateralization between the portomesenteric (PM) and gastrosplenic (GS) compartments was present in each case. In four patients with a wide-open shunt, the direction of collateral flow was from the PM to the GS compartment. In one child in whom the shunt was partially obstructed, the flow was from the GS to the PM compartment. In all 17 successful cases, esophageal variceal hemorrhage ceased, and there were no instances of hepatic encephalopathy. It is concluded that DSS is a safe and effective surgical procedure for the treatment of esophageal bleeding in children. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:6978110

[Effects of intra-arterial infusion of 3-bromopyruvate on metastases and survival benefit of hepatic VX2 tumor in rabbits].

PubMed

Jiang, Xiong-ying; Zhang, Xiao-ping; Huang, Jin-hua; Luo, Rong-guang; Miao, Bi-jian; Wang, Yan

2013-10-22

To evaluate the metastasis and survival of an intra-arterial infusion of 3-bromopyruvate (3-BrPA) on hepatic VX2 tumor in rabbits. VX2 tumor was implanted in left lateral lobe of liver of 18 white New Zealand rabbits. The animals were randomized into 3 groups (n = 6 each) and underwent an intra-arterial infusion of phosphate-buffered saline or 3-BrPA via hepatic artery at 14 days post-implantation. At 28 days post-implantation, 3 rabbits in each group were sacrificed. The abdomen of these rabbits was opened and inspected for metastases. Then the survival of the remaining rabbits was observed. At 28 days post-implantation, in PBS group, there were intrahepatic metastasis and abdominal cavity dissemination (n = 3), renal metastases (n = 2) and lung metastases (n = 2); in early 3-BrPA infusion group, intrahepatic metastasis (n = 2), abdominal cavity dissemination (n = 1) and lung metastases (n = 1); in late 3-BrPA infusion group, intrahepatic metastasis (n = 1) and lung metastases (n = 1). The survival of the remaining animals was observed. Rabbits in early 3-BrPA infusion group survived significantly longer than those in PBS group [(27 ± 5) vs (17 ± 3) days, P = 0.041]; rabbits in late 3-BrPA infusion group [(42 ± 6) days] survived significantly longer than those in early 3-BrPA infusion group (P = 0.007). An intra-arterial infusion of 3-BrPA could reduce metastasis and prolong survival in rabbits with hepatic VX2 tumor. The earlier the infusion, the better the outcome.

Percutaneous Mesocaval Shunt Creation in a Patient with Chronic Portal and Superior Mesenteric Vein Thrombosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bercu, Zachary L., E-mail: zachary.bercu@mountsinai.org; Sheth, Sachin B., E-mail: sachinsheth@gmail.com; Noor, Amir, E-mail: amir.noor@gmail.com

The creation of a transjugular intrahepatic portosystemic shunt (TIPS) is a critical procedure for the treatment of recurrent variceal bleeding and refractory ascites in the setting of portal hypertension. Chronic portal vein thrombosis remains a relative contraindication to conventional TIPS and options are limited in this scenario. Presented is a novel technique for management of refractory ascites in a patient with hepatitis C cirrhosis and chronic portal and superior mesenteric vein thrombosis secondary to schistosomiasis and lupus anticoagulant utilizing fluoroscopically guided percutaneous mesocaval shunt creation.

Congenital extrahepatic portosystemic shunts (Abernethy malformation): a histopathologic evaluation.

PubMed

Lisovsky, Mikhail; Konstas, Angelos A; Misdraji, Joseph

2011-09-01

Congenital extrahepatic portosystemic shunt, also known as Abernethy malformation, is a rare malformation in which intestinal and splenic venous blood bypasses the liver and drains into systemic veins. Aside from the complete or near-complete absence of portal veins, other histologic features of Abernethy malformation have not been evaluated in the literature. The goal of this study was to detail the hepatic histopathology in 5 patients with Abernethy malformation diagnosed at our institution. Paraffin-embedded tissue sections from 1 explant, 2 liver tumor resections, and 2 liver biopsies were evaluated using hematoxylin and eosin stains, reticulin, elastic, and trichrome stains, and immunohistochemistry for D2-40. Histologic findings included absence of portal veins in small portal tracts, absent or hypoplastic portal veins in medium-sized and large-sized portal tracts, isolated capillaries and arterioles in the lobules, hypertrophy of hepatic artery branches, remodeling of the liver architecture, and nodular regenerative hyperplasia in 1 case. Two patients had hepatocellular carcinoma without cirrhosis, and 2 had focal nodular hyperplasia. In addition to loss of portal veins, Abernethy malformation is characterized by multiple abnormalities due to remodeling of the hepatic vasculature. Abernethy malformation may also be associated with hepatocellular carcinoma and focal nodular hyperplasia in some patients.

Harmonic Resonance in Power Transmission Systems due to the Addition of Shunt Capacitors

NASA Astrophysics Data System (ADS)

Patil, Hardik U.

Shunt capacitors are often added in transmission networks at suitable locations to improve the voltage profile. In this thesis, the transmission system in Arizona is considered as a test bed. Many shunt capacitors already exist in the Arizona transmission system and more are planned to be added. Addition of these shunt capacitors may create resonance conditions in response to harmonic voltages and currents. Such resonance, if it occurs, may create problematic issues in the system. It is main objective of this thesis to identify potential problematic effects that could occur after placing new shunt capacitors at selected buses in the Arizona network. Part of the objective is to create a systematic plan for avoidance of resonance issues. For this study, a method of capacitance scan is proposed. The bus admittance matrix is used as a model of the networked transmission system. The calculations on the admittance matrix were done using Matlab. The test bed is the actual transmission system in Arizona; however, for proprietary reasons, bus names are masked in the thesis copy intended for the public domain. The admittance matrix was obtained from data using the PowerWorld Simulator after equivalencing the 2016 summer peak load (planning case). The full Western Electricity Coordinating Council (WECC) system data were used. The equivalencing procedure retains only the Arizona portion of the WECC. The capacitor scan results for single capacitor placement and multiple capacitor placement cases are presented. Problematic cases are identified in the form of 'forbidden response. The harmonic voltage impact of known sources of harmonics, mainly large scale HVDC sources, is also presented. Specific key results for the study indicated include: (1) The forbidden zones obtained as per the IEEE 519 standard indicates the bus 10 to be the most problematic bus. (2) The forbidden zones also indicate that switching values for the switched shunt capacitor (if used) at bus 3 should be

Passively Shunted Piezoelectric Damping of Centrifugally-Loaded Plates

NASA Technical Reports Server (NTRS)

Duffy, Kirsten P.; Provenza, Andrew J.; Trudell, Jeffrey J.; Min, James B.

2009-01-01

Researchers at NASA Glenn Research Center have been investigating shunted piezoelectric circuits as potential damping treatments for turbomachinery rotor blades. This effort seeks to determine the effects of centrifugal loading on passively-shunted piezoelectric - damped plates. Passive shunt circuit parameters are optimized for the plate's third bending mode. Tests are performed both non-spinning and in the Dynamic Spin Facility to verify the analysis, and to determine the effectiveness of the damping under centrifugal loading. Results show that a resistive shunt circuit will reduce resonant vibration for this configuration. However, a tuned shunt circuit will be required to achieve the desired damping level. The analysis and testing address several issues with passive shunt circuit implementation in a rotating system, including piezoelectric material integrity under centrifugal loading, shunt circuit implementation, and tip mode damping.

Contemporary survival of patients with pulmonary arterial hypertension and congenital systemic to pulmonary shunts

PubMed Central

Chungsomprasong, Paweena; Bositthipichet, Densiri; Ketsara, Salisa; Titaram, Yuttapon; Chanthong, Prakul; Kanjanauthai, Supaluck

2018-01-01

Objective To compare survival of patients with newly diagnosed pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) according to various clinical classifications with classifications of anatomical-pathophysiological systemic to pulmonary shunts in a single-center cohort. Methods All prevalent cases of PAH-CHD with hemodynamic confirmation by cardiac catheterization in 1995–2015 were retrospectively reviewed. Patients who were younger than three months of age, or with single ventricle following surgery were excluded. Baseline characteristics and clinical outcomes were retrieved from the database. The survival analysis was performed at the end of 2016. Prognostic factors were identified using multivariate analysis. Results A total of 366 consecutive patients (24.5 ± 17.6 years of age, 40% male) with PAH-CHD were analyzed. Most had simple shunts (85 pre-tricuspid, 105 post-tricuspid, 102 combined shunts). Patients with pre-tricuspid shunts were significantly older at diagnosis in comparison to post-tricuspid, combined, and complex shunts. Clinical classifications identified patients as having Eisenmenger syndrome (ES, 26.8%), prevalent left to right shunt (66.7%), PAH with small defect (3%), or PAH following defect correction (3.5%). At follow-up (median = 5.9 years; 0.1–20.7 years), no statistically significant differences in survival rate were seen among the anatomical-pathophysiological shunts (p = 0.1). Conversely, the clinical classifications revealed that patients with PAH-small defect had inferior survival compared to patients with ES, PAH post-corrective surgery, or PAH with prevalent left to right shunt (p = 0.01). Significant mortality risks were functional class III, age < 10 years, PAH-small defect, elevated right atrial pressure > 15 mmHg, and baseline PVR > 8 WU•m.2 Conclusion Patients with PAH-CHD had a modest long-term survival. Different anatomical-pathophysiological shunts affect the natural presentation, while

[Portal vein thrombosis associated with hepatic encephalopathy].

PubMed

Iwatani, Nao; Inatomi, Yuichiro; Yonehara, Toshiro; Fujioka, Shodo; Hashimoto, Yoichiro; Hirano, Teruyuki; Uchino, Makoto

2005-03-01

A 54-year-old man who had been administered chlormadinone acetate 3 months after prostatectomy for prostate cancer, acutely developed disorientation and memory disturbance. Six days later, he experienced high grade fever and epigastralgia. He was suspected to have hepatic encephalopathy, because the Fischer ratio was low although serum ammonia level remained normal. Further examinations including abdominal echography and CT scan disclosed a thrombus extending from the portal vein to the superior mesenteric vein together with abnormal collateral vessels originating from the portal vein. He was successfully treated with warfarin potassium, urokinase and heparin sodium. It was suggested that the patient developed hepatic encephalopathy due to portal-systemic circulation shunting secondary to portal vein thrombosis.

Regional cerebral blood flow assessed by single photon emission computed tomography (SPECT) in dogs with congenital portosystemic shunt and hepatic encephalopathy.

PubMed

Or, Matan; Peremans, Kathelijne; Martlé, Valentine; Vandermeulen, Eva; Bosmans, Tim; Devriendt, Nausikaa; de Rooster, Hilde

2017-02-01

Regional cerebral blood flow (rCBF) in eight dogs with congenital portosystemic shunt (PSS) and hepatic encephalopathy (HE) was compared with rCBF in eight healthy control dogs using single photon emission computed tomography (SPECT) with a 99m technetium-hexamethylpropylene amine oxime ( 99m Tc-HMPAO) tracer. SPECT scans were abnormal in all PSS dogs. Compared to the control group, rCBF in PSS dogs was significantly decreased in the temporal lobes and increased in the subcortical (thalamic and striatal) area. Brain perfusion imaging alterations observed in the dogs with PSS and HE are similar to those in human patients with HE. These findings suggest that dogs with HE and PSS have altered perfusion of mainly the subcortical and the temporal regions of the brain. Copyright © 2016 Elsevier Ltd. All rights reserved.

49 CFR 236.57 - Shunt and fouling wires.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Shunt and fouling wires. 236.57 Section 236.57...: All Systems Track Circuits § 236.57 Shunt and fouling wires. (a) Except as provided in paragraph (b) of this section, shunt wires and fouling wires hereafter installed or replaced shall consist of at...

49 CFR 236.57 - Shunt and fouling wires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Shunt and fouling wires. 236.57 Section 236.57...: All Systems Track Circuits § 236.57 Shunt and fouling wires. (a) Except as provided in paragraph (b) of this section, shunt wires and fouling wires hereafter installed or replaced shall consist of at...

Patients with a Normal Pressure Hydrocephalus Shunt Have Fewer Complications than Do Patients with Other Shunts.

PubMed

Schenker, Pascale; Stieglitz, Lennart H; Sick, Beate; Stienen, Martin N; Regli, Luca; Sarnthein, Johannes

2018-02-01

Ventriculoperitoneal (VP) shunting is a well-established therapy for hydrocephalus. However, complications are frequent. The incidence of idiopathic normal pressure hydrocephalus (NPH) increases with the aging of the population. We evaluated the functional status of patients and the classification of complications associated with VP shunt procedures in our center. We recorded all VP shunt procedures in our prospective patient registry from January 2013 to December 2015. Functional outcome (Karnofsky Performance Status [KPS] and modified Rankin Scale) and complications were compiled from patient records. Any deviation from the normal postoperative course within 3 months after surgery was considered a complication. Complications were classified with the therapy-oriented Clavien-Dindo grading system. We evaluated potential risk factors with a logistic regression model. From 285 procedures in the reporting period, 90 were excluded, resulting in 195 patients. Among those patients, 174 (90%) were shunt implantations and 21 (11%) were shunt revisions. Forty-four shunts (23%) were implanted for NPH. Median KPS improved over the first year after surgery. Although some type of complication was observed in 114 patients (58%), 60 of those complications (31%) did not require surgical treatment (Clavien-Dindo grade <3). In 50 patients (26%), the complication concerned the shunt itself. A high KPS at admission and NPH as underlying indication significantly reduced the odds ratio for a complication. Although shunt surgery has a high general rate of complications, this rate is significantly lower for patients with NPH. The decision for shunting in patients with NPH should consider the low complication rate specific for the group of patients with NPH. Copyright © 2017 Elsevier Inc. All rights reserved.

Stent Angioplasty of Closed Mesocaval Shunt in a Patient with Budd-Chiari Syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sancak, Tanzer; Karagulle, Ayse Tuba; Bilgic, Sadik

Budd-Chiari syndrome (BCS) is an uncommon disorder caused by hepatic venous outflow obstruction. It is characterized by ascites, hepatomegaly and abdominal pain. Percutaneous intervention shave recently been used for the treatment of BCS. We present a case of BCS with a closed mesocaval shunt which was reopened with a self-expandable metallic stent.

Removal of intra-abdominal visceral adipose tissue improves glucose tolerance in rats: role of hepatic triglyceride storage.

PubMed

Foster, Michelle T; Shi, Haifei; Seeley, Randy J; Woods, Stephen C

2011-10-24

Epidemiological studies have demonstrated a strong link between increased visceral fat and metabolic syndrome. In rodents, removal of intra-abdominal but non-visceral fat improves insulin sensitivity and glucose homeostasis, though previous studies make an imprecise comparison to human physiology because actual visceral fat was not removed. We hypothesize that nutrient release from visceral adipose tissue may have greater consequences on metabolic regulation than nutrient release from non-visceral adipose depots since the latter drains into systemic but not portal circulation. To assess this we surgically decreased visceral white adipose tissue (~0.5 g VWATx) and compared the effects to removal of non-visceral epididymal fat (~4 g; EWATx), combination removal of visceral and non-visceral fat (~4.5 g; EWATx/VWATx) and sham-operated controls, in chow-fed rats. At 8 weeks after surgery, only the groups with visceral fat removed had a significantly improved glucose tolerance, although 8 times more fat was removed in EWATx compared with VWATx. This suggests that mechanisms controlling glucose metabolism are relatively more sensitive to reductions in visceral adipose tissue mass. Groups with visceral fat removed also had significantly decreased hepatic lipoprotein lipase (LPL) and triglyceride content compared with controls, while carnitine palmitoyltransferase (CPT-1A) was decreased in all fat-removal groups. In a preliminary experiment, we assessed the opposite hypothesis; i.e., we transplanted excess visceral fat from a donor rat to the visceral cavity (omentum and mesentery), which drains into the hepatic portal vein, of a recipient rat but observed no major metabolic effect. Overall, our results indicate surgical removal of intra-abdominal fat improves glucose tolerance through mechanism that may be mediated by reductions in liver triglyceride. Published by Elsevier Inc.

Removal of Intra-abdominal Visceral Adipose Tissue Improves Glucose Tolerance in Rats: Role of Hepatic Triglyceride Storage

PubMed Central

Foster, Michelle T.; Shi, Haifei; Seeley, Randy J.; Woods, Stephen C.

2011-01-01

Epidemiological studies have demonstrated a strong link between increased visceral fat and metabolic syndrome. In rodents, removal of intra-abdominal but non-visceral fat improves insulin sensitivity and glucose homeostasis, though previous studies make an imprecise comparison to human physiology because actual visceral fat was not removed. We hypothesize that nutrient release from visceral adipose tissue may have greater consequences on metabolic regulation than nutrient release from non-visceral adipose depots since the latter drains into systemic but not portal circulation. To assess this we surgically decreased visceral white adipose tissue (~0.5 g VWATx) and compared the effects to removal of non-visceral epididymal fat (~4 g; EWATx), combination removal of visceral and non-visceral fat (~4.5 g; EWATx/VWATx) and sham-operated controls, in chow-fed rats. At 8 weeks after surgery, only the groups with visceral fat removed had a significantly improved glucose tolerance, although 8 times more fat was removed in EWATx compared with VWATx. This suggests that mechanisms controlling glucose metabolism are relatively more sensitive to reductions in visceral adipose tissue mass. Groups with visceral fat removed also had significantly decreased hepatic lipoprotein lipase (LPL) and triglyceride content compared with controls, while carnitine palmitoyltransferase (CPT-1A) was decreased in all fat-removal groups. In a preliminary experiment, we assessed the opposite hypothesis; i.e., we transplanted excess visceral fat from a donor rat to the visceral cavity (omentum and mesentery), which drains into the hepatic portal vein, of a recipient rat but observed no major metabolic effect. Overall, our results indicate surgical removal of intra-abdominal fat improves glucose tolerance through mechanism that may be mediated by reductions in liver triglyceride. PMID:21683727

A 735 kV shunt reactors automatic switching system for Hydro-Quebec network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernard, S.; Trudel, G.; Scott, G.

1996-11-01

In recent years, Hydro-Quebec has undertaken a major program to upgrade the reliability of its transmission system. Much efforts have been directed toward increasing the system`s capacity to withstand extreme contingencies, usually caused by multiple incidents or the successive tripping of transmission lines. In order to counter such events, Hydro-Quebec has adopted a defensive scheme. Based entirely on automatic action, this scheme will mainly rely on: a 735 kV shunt reactor switching system (called MAIS); a generation rejection and/or remote load-shedding system (called RPTC); an underfrequency load-shedding system. The MAIS system, which is the subject of this paper, will bemore » implemented in 22 substations and is required to control voltage on the system after a severe event. Each MAIS system, acting locally, is entirely independent and will close or trip shunt reactors in response to local conditions.« less

Maintenance of pulmonary vasculature tone by blood derived from the inferior vena cava in a rabbit model of cavopulmonary shunt.

PubMed

Ikai, Akio; Shirai, Mikiyasu; Nishimura, Kazunobu; Ikeda, Tadashi; Kameyama, Takayuki; Ueyama, Koji; Komeda, Masashi

2005-01-01

After cavopulmonary shunt in which the superior vena cava is anastomosed to the right pulmonary artery, the right lung is in a unique condition without flow pulsatility and hepatic venous effluent. In a previous study, we reported that hypoxic pulmonary vasoconstriction disappeared in the pulmonary circulation after cavopulmonary shunt. In this study, however, to investigate the influence of pulsatility and hepatic venous effluent on hypoxic pulmonary vasoconstriction in the pulmonary circulation, we developed an alternative cavopulmonary shunt rabbit model that included hepatic venous effluent in the pulmonary circulation and reduced the pulsatility of the pulmonary arterial blood flow. We then observed the physiologic characteristics of the peripheral pulmonary artery after cavopulmonary shunt, specifically the disappearance of hypoxic pulmonary vasoconstriction. Sixteen Japanese white rabbits (12-16 weeks old) were used in this study. With general anesthesia, a cavopulmonary shunt was established by anastomosing the right superior vena cava to the right pulmonary artery in an end-to-side fashion. Of the 16 rabbits for the study, the proximal right pulmonary artery was completely ligated in 5 (atresia group) and partially ligated in 6 (stenosis group). Sham operation was performed in the remaining 5 rabbits. Two weeks later, we analyzed the response of the pulmonary artery (which was divided into three categories: segmental, lobular, and acinar level artery) to hypoxia (8% oxygen inhalation) with a specially designed video radiographic system. Morphometric analysis of the resistance pulmonary artery was done in each group after angiography. Mean pressure and pulse pressure in the right pulmonary artery were not significantly different between the atresia and stenosis groups. The mean pulmonary artery pressures in the atresia and stenosis groups were 8 and 11 mm Hg, respectively. However, the pulse pressure was less than 2 mm Hg in both groups. The baseline

Indications and results of systemic to pulmonary shunts: results from a national database.

PubMed

Dorobantu, Dan Mihai; Pandey, Ragini; Sharabiani, Mansour Taghavi; Mahani, Alireza Shahidzadeh; Angelini, Gianni Davide; Martin, Robin Peter; Stoica, Serban Constantin

2016-06-01

The systemic-to-pulmonary shunt (SPS) remains an important palliative therapy in many congenital heart defects. Unlike other surgical treatments, the mortality after shunt operations has risen. We used an audit dataset to investigate potential reasons for this change and to report national results. A total of 1993 patients classified in 13 diagnoses underwent an SPS procedure between 2000 and 2013. Indication trends by era and also results before repair or next stage are reported. A dynamic hazard model with competing risks and modulated renewal was used to determine predictors of outcomes. The usage of SPS in Tetralogy of Fallot (ToF) has significantly decreased in the last decade, with cases of single ventricle (SV) and pulmonary atresia (PA) with septal communication increasing (P < 0.001 for trends). This is correlated with an increase of early mortality from 5.1% in the first half of the decade to 9.8% in the latter (P = 0.007 for trend). At 1.5 years, 13.9% of patients have died, 17.8% had a shunt reintervention and 68.3% of patients are alive and reintervention-free. Low weight, PA-intact septum, SV and central shunt type are among the factors associated with increased mortality, whereas PA-ventricular septal defect, corrected transposition, isomerism, central shunt and low weight are among those associated with increased reintervention, also having a dynamic effect on the relative risk when compared with ToF patients. Shunt reinterventions are not associated with worse outcomes when adjusted by other covariates, but they do have higher 30-day mortality if occurring earlier than 30 days from the index (P < 0.001). Patients operated in later years were found to have significantly lower survival at a distance from index. The observed historical rise in mortality for shunt operations relates to complex factors including changing practice for repair of ToF and for univentricular palliation. PA and SV patients are the groups of patients at the highest risk of

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

PubMed

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

2016-09-01

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

Increasing cyanosis early after cavopulmonary connection caused by abnormal systemic venous channels.

PubMed

Gatzoulis, M A; Shinebourne, E A; Redington, A N; Rigby, M L; Ho, S Y; Shore, D F

1995-02-01

To show that abnormal systemic venous channels in patients who undergo cavopulmonary anastomoses can become manifest and haemodynamically important only after surgery despite detailed preoperative investigation. Descriptive study of patients fulfilling the above criteria selected from hospital records over the past three years. A tertiary referral centre. Of the three cases identified, two were isomeric, one with left atrial isomerism and hemiazygos continuation of the inferior vena cava who underwent bilateral bidirectional Glenn anastomoses and one with right isomerism who underwent total cavopulmonary anastomosis. Case 3 had absent left atrioventricular connection with a hypoplastic left lung and underwent a classic right Glenn procedure. All three cases presented with progressive cyanosis in the early postoperative period. Postoperative angiography in case 1 showed a remnant of a left inferior vena cava draining to the atrium to have become grossly dilated causing cyanosis, which resolved after redirection of this vessel and of the hepatic veins into the right pulmonary artery with an intra-atrial baffle. Cyanosis in case 2 was caused by intra-hepatic shunting to a hepatic vein draining to the left of the intra-atrial baffle. The diagnosis was made at necropsy, being overlooked on postoperative angiography. Repeat angiography in case 3 showed progressive dilatation of a small left superior vena cava to coronary sinus. Test occlusion with a view to embolisation revealed hitherto an undemonstrated hemiazygos continuation of inferior caval to brachiocephalic vein. The patient underwent surgical ligation of these two venous channels. Despite appropriate investigation some "abnormal" venous pathways manifest themselves, dilate, and become haemodynamically important only after surgical cavopulmonary anastomoses. In the presence of early postoperative cyanosis "new" systemic venous collateral channels should be considered as a possible cause, which may require

Prevalence of hepatitis C virus and human immunodeficiency virus in a group of patients newly diagnosed with active tuberculosis in Porto Alegre, Southern Brazil.

PubMed

Costi, Cintia; Grandi, Tarciana; Halon, Maria Laura; Silva, Márcia Susana Nunes; Silva, Cláudia Maria Dornelles da; Gregianini, Tatiana Schäffer; Possuelo, Lia Gonçalves; Jarczewski, Carla Adriane; Niel, Christian; Rossetti, Maria Lucia Rosa

2017-04-01

Porto Alegre is the Brazilian state capital with second highest incidence of tuberculosis (TB) and the highest proportion of people infected with human immunodeficiency virus (HIV) among patients with TB. Hepatitis C virus (HCV) infection increases the risk of anti-TB drug-induced hepatotoxicity, which may result in discontinuation of the therapy. The aim of this study was (i) to estimate prevalence of HCV and HIV in a group of patients newly diagnosed with active TB in a public reference hospital in Porto Alegre and (ii) to compare demographic, behavioural, and clinical characteristics of patients in relation to their HCV infection status. One hundred and thirty-eight patients with TB were tested for anti-HCV antibody, HCV RNA, and anti-HIV1/2 antibody markers. HCV RNA from real-time polymerase chain reaction (PCR)-positive samples was submitted to reverse transcription and PCR amplification. The 5' non-coding region of the HCV genome was sequenced, and genotypes of HCV isolates were determined. Anti-HCV antibody, HCV RNA, and anti-HIV antibodies were detected in 27 [20%; 95% confidence interval (CI), 13-26%], 17 (12%; 95% CI, 7-18%), and 34 (25%; 95% CI, 17-32%) patients, respectively. HCV isolates belonged to genotypes 1 (n = 12) and 3 (n = 4). Some characteristics were significantly more frequent in patients infected with HCV. Among them, non-white individuals, alcoholics, users of illicit drugs, imprisoned individuals, and those with history of previous TB episode were more commonly infected with HCV (p < 0.05). HCV screening, including detection of anti-HCV antibody and HCV RNA, will be important to improving the management of co-infected patients, given their increased risk of developing TB treatment-related hepatotoxicity.

Exercise Physiology and Pulmonary Hemodynamic Abnormality in PH Patients with Exercise Induced Venous-To-Systemic Shunt.

PubMed

Guo, Jian; Shi, Xue; Yang, Wenlan; Gong, Sugang; Zhao, Qinhua; Wang, Lan; He, Jing; Shi, Xiaofang; Sun, Xingguo; Liu, Jinming

2014-01-01

To identify the pulmonary hypertension (PH) patients who develop an exercise induced venous-to-systemic shunt (EIS) by performing the cardiopulmonary exercise test (CPET), analyse the changes of CPET measurements during exercise and compare the exercise physiology and resting pulmonary hemodynamics between shunt-PH and no-shunt-PH patients. Retrospectively, resting pulmonary function test (PFT), right heart catheterization (RHC), and CPET for clinical evaluation of 104 PH patients were studied. Considering all 104 PH patients by three investigators, 37 were early EIS+, 61 were EIS-, 3 were late EIS+, and 3 others were placed in the discordant group. PeakVO2, AT and OUES were all reduced in the shunt-PH patients compared with the no-shunt-PH subjects, whereas VE/VCO2 slope and the lowest VE/VCO2 increased. Besides, the changes and the response characteristics of the key CPET parameters at the beginning of exercise in the shunt group were notably different from those of the no shunt one. At cardiac catheterization, the shunt patients had significantly increased mean pulmonary artery pressure (mPAP), mean right atrial pressure (mRAP) and pulmonary vascular resistance (PVR), reduced cardiac output (CO) and cardiac index (CI) compared with the no shunt ones (P<0.05). Resting CO was significantly correlated with exercise parameters of AT (r = 0.527, P<0.001), OUES (r = 0.410, P<0.001) and Peak VO2 (r = 0.405, P<0.001). PVR was significantly, but weakly, correlated with the above mentioned CPET parameters. CPET may allow a non-invasive method for detecting an EIS and assessing the severity of the disease in PH patients.

Monitoring Urban Quality of Life: The Porto Experience

ERIC Educational Resources Information Center

Santos, Luis Delfim; Martins, Isabel

2007-01-01

This paper describes the monitoring system of the urban quality of life developed by the Porto City Council, a new tool being used to support urban planning and management. The two components of this system--a quantitative approach based on statistical indicators and a qualitative analysis based on the citizens' perceptions of the conditions of…

Associations of systemic sphingolipids with measures of hepatic function in liver cirrhosis are related to cholesterol.

PubMed

Krautbauer, Sabrina; Wiest, Reiner; Liebisch, Gerhard; Buechler, Christa

2017-07-01

Lipoprotein particles are composed of various lipid classes including cholesterol and sphingolipids, and are low in serum of patients with liver cirrhosis. Hepatic decompensation is associated with a further decline of lipoproteins. Aim of the present work was to evaluate whether ceramide and sphingomyelin species are similarly changed in patients with liver cirrhosis and whether these variations are related to systemic cholesterol levels. In a cohort of 45 patients suffering from liver cirrhosis, cholesteryl ester species and subsequently total cholesterol were identified to be negatively associated with model of end stage liver disease (MELD) score. Indeed, the negative correlations of ceramide (Cer) and sphingomyelin (SM) species with MELD score, bilirubin and anti-thrombin 3 were non-significant after adjustment for cholesterol. Cer/SM ratios of species with identical acyl chains were not related to Child-Pugh or MELD score indicating that both lipids are comparably changed. Further, cholesterol levels and concentrations of all sphingolipids measured were similar in systemic, hepatic vein and portal vein blood. Cholesterol and distinct sphingolipids were similar before and 3 months after insertion of a transjugular intrahepatic portosystemic shunt while hexosylceramide 24:1 was significantly induced. It is concluded that analysis of distinct systemic sphingolipid species is not superior to measurement of cholesterol as non-invasive marker of hepatic injury in patients with liver cirrhosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Short-term fasting induces intra-hepatic lipid accumulation and decreases intestinal mass without reduced brush-border enzyme activity in mink (Mustela vison) small intestine.

PubMed

Bjornvad, C R; Elnif, J; Sangild, P T

2004-11-01

For many mammalian species short-term fasting is associated with intestinal atrophy and decreased digestive capacity. Under natural conditions, strictly carnivorous animals often experience prey scarcity during winter, and they may therefore be particularly well adapted to short-term food deprivation. To examine how the carnivorous gastrointestinal tract is affected by fasting, small-intestinal structure, brush-border enzyme activities and hepatic structure and function were examined in fed mink (controls) and mink that had been fasted for 1-10 days. During the first 1-2 days of fasting, intestinal mass decreased more rapidly than total body mass and villus heights were reduced 25-40%. In contrast, tissue-specific activity of the brush-border enzymes sucrase, maltase, lactase, aminopeptidase A and dipeptidylpeptidase IV increased 0.5- to 1.5-fold at this time, but returned to prefasting levels after 6 days of fasting. After 6-10 days of fasting there was a marked increase in the activity of hepatic enzymes and accumulation of intra-hepatic lipid vacuoles. Thus, mink may be a useful model for studying fasting-induced intestinal atrophy and adaptation as well as mechanisms involved in accumulation of intra-hepatic lipids following food deprivation in strictly carnivorous domestic mammals, such as cats and ferrets.

Long-term results of small-diameter proximal splenorenal venous shunt: A retrospective study

PubMed Central

Chen, Hao; Yang, Wei-Ping; Yan, Ji-Qi; Li, Qin-Yu; Ma, Di; Li, Hong-Wei

2011-01-01

AIM: To investigate recurrent variceal hemorrhage and long-term survival rates of patients treated with partial proximal splenorenal venous shunt. METHODS: Patients with variceal hemorrhage who were treated with small-diameter proximal splenorenal venous shunt in Ruijin Hospital between 1996 and 2009 were included in this study. Shunt diameter was determined before operation using Duplex Doppler ultrasonography. Peri-operative and long-term results in term of rehemorrhage, encephalopathy and mortality were followed up. RESULTS: Ninety-eight patients with Child A and B variceal hemorrhage received small-diameter proximal splenorenal venous shunt with a diameter of 7-10 mm. After operation, the patients’ mean free portal pressure (P < 0.01) and the flow rate of main portal vein (P < 0.01) decreased significantly compared with that before operation. The rates of rebleeding and mortality were 6.12% (6 cases) and 2.04% (2 cases), respectively. Ninety-one patients were followed up for 7 mo-14 years (median, 48.57 mo). Long-term rates of rehemorrhage and encephalopathy were 4.40% (4 cases) and 3.30% (3 cases), respectively. Thirteen patients (14.29%) died mainly due to progressive hepatic dysfunction. Five- and ten-year survival rates were 82.12% and 71.24%, respectively. CONCLUSION: Small-diameter proximal splenorenal venous shunt affords protection against variceal rehemorrhage with a low occurrence of encephalopathy in patients with normal liver function. PMID:21876638

Intravascular Ultrasound Guidance for Transjugular Intrahepatic Portosystemic Shunt Procedure in a Swine Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kew, Jacqueline; Davies, Roger P.

2004-01-15

A new method is described for guiding hepato-portalvenous puncture using a longitudinal side-view intravascular ultrasound(L-IVUS) transducer to assist in the performance of transjugularintrahepatic portosystemic shunt (TIPS) in three Australian swine.Simultaneous L-IVUS with an AcuNav (registered) 5-10 MHz 10 Fr transducer(Acuson Corporation, Mountain View, CA, USA) and fluoroscopy guidance was used to image and monitor the hepatic to portal venous puncture,dilatation of the tract, and deployment of the TIPS stent. Flow through the shunt could be demonstrated with both L-IVUS and angiography. TIPS was successful in all swine. The time for portal vein puncture once the target portal vein was identifiedmore » was reduced at each attempt. The number of portal vein puncture attempts was 2, 1, and 1. No post-procedural complication was evident. L-IVUS-guided TIPS is practical and has the potential to improve safety by permitting simultaneous ultrasound and fluoroscopic imaging of the needle and target vascular structures. This technique allows for a more streamlined approach to TIPS, decreasing the fluoroscopic time (hence,decreasing the radiation exposure to the staff and patient) and anesthetic time. In addition, there are improved safety benefits obviating the need for wedged portography, facilitating avoidance of bile duct and hepatic arterial puncture, and minimizing hepatic injury by decreasing liver capsular puncture and the attendant risks.« less

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

PubMed Central

Swetapadma, Aleena; Yadav, Anamika

2015-01-01

Many schemes are reported for shunt fault location estimation, but fault location estimation of series or open conductor faults has not been dealt with so far. The existing numerical relays only detect the open conductor (series) fault and give the indication of the faulty phase(s), but they are unable to locate the series fault. The repair crew needs to patrol the complete line to find the location of series fault. In this paper fuzzy based fault detection/classification and location schemes in time domain are proposed for both series faults, shunt faults, and simultaneous series and shunt faults. The fault simulation studies and fault location algorithm have been developed using Matlab/Simulink. Synchronized phasors of voltage and current signals of both the ends of the line have been used as input to the proposed fuzzy based fault location scheme. Percentage of error in location of series fault is within 1% and shunt fault is 5% for all the tested fault cases. Validation of percentage of error in location estimation is done using Chi square test with both 1% and 5% level of significance. PMID:26413088

Large focal nodular hyperplasia and extrahepatic portosystemic shunt in a male patient: multi-modality imaging features.

PubMed

Kitzing, Yu Xuan; Gallagher, James; Waugh, Richard

2011-10-01

Congenital extrahepatic portocaval shunt is a rare condition that is described mostly in female patients. We report an unusual case of a young adult male patient with type 1 congenital extrahepatic portocaval shunt with associated development of a focal nodular hyperplasia on a background of regenerative nodules. With multi-slice CT utilisation, there is increased detection of portocaval malformation in asymptomatic patients. This congenital variant is clinically significant with associated development of hepatocellular lesions, hepatic dysfunction and/or encephalopathy. © 2011 The Authors. Journal of Medical Imaging and Radiation Oncology © 2011 The Royal Australian and New Zealand College of Radiologists.

Double-Balloon-Assisted n-Butyl-2-Cyanoacrylate Embolization of Intrahepatic Arterioportal Shunt Prior to Chemoembolization of Hepatocellular Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takao, Hidemasa, E-mail: takaoh-tky@umin.ac.jp; Shibata, Eisuke; Ohtomo, Kuni

A case of multiple hepatocellular carcinomas with a severe intrahepatic arterioportal shunt that was successfully embolized with n-butyl-2-cyanoacrylate with coaxial double-balloon occlusion prior to transcatheter arterial chemoembolization is presented. A proximal balloon positioned at the proper hepatic artery was used for flow control, and a coaxial microballoon, positioned in the closest of three arterial feeding branches to the arterioportal shunt, was used to control the delivery of n-butyl-2-cyanoacrylate. This coaxial double-balloon technique can prevent proximal embolization and distal migration of n-butyl-2-cyanoacrylate and enable precise control of the distribution of n-butyl-2-cyanoacrylate. It could also be applicable to n-butyl-2-cyanoacrylate embolization for othermore » than intrahepatic arterioportal shunt.« less

Hepatic Encephalopathy: From the Pathogenesis to the New Treatments

PubMed Central

Cordoba, Juan

2014-01-01

Hepatic encephalopathy is a frequent and serious complication of liver cirrhosis; the pathophysiology of this complication is not fully understood although great efforts have been made during the last years. There are few prospective studies on the epidemiology of this complication; however, it is known that it confers with high short-term mortality. Hepatic encephalopathy has been classified into different groups depending on the degree of hepatic dysfunction, the presence of portal-systemic shunts, and the number of episodes. Due to the large clinical spectra of overt EH and the complexity of cirrhotic patients, it is very difficult to perform quality clinical trials for assessing the efficacy of the treatments proposed. The physiopathology, clinical manifestation, and the treatment of HE is a challenge because of the multiple factors that converge and coexist in an episode of overt HE. PMID:27335836

[Shunt and short circuit].

PubMed

Rangel-Abundis, Alberto

2006-01-01

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

Portosystemic shunt as a cause of congenital hyperinsulinemic hypoglycemia.

PubMed

Yoshii, Keisuke; Noda, Masahiro; Naiki, Yasuhiro; Horikawa, Reiko

2017-04-01

Congenital hyperinsulinemic hypoglycemia (CHH) is characterized by the inappropriate secretion of insulin from pancreatic beta cells in the presence of hypoglycemia. We herein describe the case of a 5-month-old boy with CHH due to congenital portosystemic shunt (CPSS). Insulin secreted from pancreatic beta cells flows into the portal vein and is first metabolized in the liver. First-pass elimination of insulin in the liver leads to great decrease in insulin concentration by approximately 40-80% in humans. CPSS accounts for a large quantity of insulin delivery into the systemic circulation due to the lack of hepatic first-pass elimination. Hypoglycemia can result from consistently high levels of insulin after reaching normal glucose level. CPSS therefore should be considered as a rare cause of CHH, especially in the case of post-prandial hyperinsulinemic hypoglycemia. © 2017 Japan Pediatric Society.

Current concepts in congenital portosystemic shunts.

PubMed

Mankin, Kelley M Thieman

2015-05-01

Congenital portosystemic shunts (CPSS) are vascular abnormalities that allow portal blood to bypass the liver and join systemic circulation. Laboratory and imaging studies are performed preoperatively to diagnose CPSS and hopefully identify an anatomic location of the shunt. CPSS can be found in different locations in both small and large breed dogs. Most CPSS are best managed surgically. The goal of surgical management of CPSS is to slowly redirect blood from the shunting vessel through the portal vasculature while avoiding portal hypertension. Many surgical management methods are available, including open and less invasive procedures, such as laparoscopy and embolization. Copyright © 2015 Elsevier Inc. All rights reserved.

Ventricular shunt tap as a predictor of proximal shunt malfunction in children: a prospective study.

PubMed

Rocque, Brandon G; Lapsiwala, Samir; Iskandar, Bermans J

2008-06-01

The clinical diagnosis of cerebrospinal fluid (CSF) shunt malfunction can be challenging. In this prospective study, the authors evaluated a common method of interrogating shunts: the shunt tap; specifically, its ability to predict proximal malfunction. The authors performed standardized shunt taps in a consecutive series of cases involving children with suspected or proven shunt malfunction, assessing flow and, when possible, opening pressure. Data were collected prospectively, and results analyzed in light of surgical findings. A shunt tap was performed prior to 68 operative explorations in 51 patients. Of the 68 taps, 28 yielded poor or no CSF flow on aspiration. After 26 of these 28 procedures, proximal catheter obstruction was identified. After 28 taps with good CSF return and normal or low opening pressure, 18 shunts were found to have a proximal obstruction, 8 had no obstruction, and 2 had a distal obstruction. Another 12 taps with good CSF flow had high opening pressure; subsequent surgery showed distal obstruction in 11 of the shunts, and proximal obstruction in 1. The positive predictive value of poor flow was 93%, while good flow on shunt tap predicted adequate proximal catheter function in only 55% of cases. Poor flow of CSF on shunt tap is highly predictive of obstruction of the proximal catheter. Because not all patients with good flow on shunt tap underwent surgical shunt exploration, the specificity of this test cannot be determined. Nonetheless, a shunt tap that reveals good flow with a normal opening pressure can be misleading, and management of such cases should be based on clinical judgment.

The effect of partial portal decompression on portal blood flow and effective hepatic blood flow in man: a prospective study.

PubMed

Rosemurgy, A S; McAllister, E W; Godellas, C V; Goode, S E; Albrink, M H; Fabri, P J

1995-12-01

With the advent of transjugular intrahepatic porta-systemic stent shunt and the wider application of the surgically placed small diameter prosthetic H-graft portacaval shunt (HGPCS), partial portal decompression in the treatment of portal hypertension has received increased attention. The clinical results supporting the use of partial portal decompression are its low incidence of variceal rehemorrhage due to decreased portal pressures and its low rate of hepatic failure, possibly due to maintenance of blood flow to the liver. Surprisingly, nothing is known about changes in portal hemodynamics and effective hepatic blood flow following partial portal decompression. To prospectively evaluate changes in portal hemodynamics and effective hepatic blood flow brought about by partial portal decompression, the following were determined in seven patients undergoing HGPCS: intraoperative pre- and postshunt portal vein pressures and portal vein-inferior vena cava pressure gradients, intraoperative pre- and postshunt portal vein flow, and pre- and postoperative effective hepatic blood flow. With HGPCS, portal vein pressures and portal vein-inferior vena cava pressure gradients decreased significantly, although portal pressures remained above normal. In contrast to the significant decreases in portal pressures, portal vein blood flow and effective hepatic blood flow do not decrease significantly. Changes in portal vein pressures and portal vein-inferior vena cava pressure gradients are great when compared to changes in portal vein flow and effective hepatic blood flow. Reduction of portal hypertension with concomitant maintenance of hepatic blood flow may explain why hepatic dysfunction is avoided following partial portal decompression.

Hepatic encephalopathy in patients with non-cirrhotic portal hypertension: Description, prevalence and risk factors.

PubMed

Nicoletti, Valeria; Gioia, Stefania; Lucatelli, Pierleone; Nardelli, Silvia; Pasquale, Chiara; Nogas Sobrinho, Stefano; Pentassuglio, Ilaria; Greco, Francesca; De Santis, Adriano; Merli, Manuela; Riggio, Oliviero

2016-09-01

Hepatic encephalopathy (HE) is a common complication of cirrhosis but it is less studied in patients with non-cirrhotic portal hypertension (NCPH). To describe the prevalence of cognitive impairment (overt and covert HE) in NCPH patients and to identify the risk factors for its development. 51 patients with NCPH, 35 with chronic portal vein thrombosis (PVT) and 16 with idiopathic non-cirrhotic portal hypertension (INCPH), were evaluated for the presence of previous or present overt HE (OHE). The psychometric hepatic encephalopathy score and the SCAN battery were used to detect the presence of covert HE (CHE). 34 compensated cirrhotic patients were used as control. In NCPH patients, abdominal scans were performed to detect the presence of shunts. None of the patients experienced OHE at evaluation while 5.7% of PVT and 12.5% of INCPH patients referred at least one documented episode of previous OHE, similarly to patients with cirrhosis (14.7%). Even if lower than in patients with cirrhosis (64.7%), a considerable proportion of patients with chronic PVT (34.3%) and INCPH (25%) had CHE (p=0.008). The presence of a large portal-systemic shunt was the only factor significantly correlated to cognitive impairment in NCPH patients. HE is a tangible complication of NCPH and is mainly related to the presence of portal-systemic shunts. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Intra- and inter-examination repeatability of magnetic resonance spectroscopy, magnitude-based MRI, and complex-based MRI for estimation of hepatic proton density fat fraction in overweight and obese children and adults.

PubMed

Tyagi, Avishkar; Yeganeh, Omid; Levin, Yakir; Hooker, Jonathan C; Hamilton, Gavin C; Wolfson, Tanya; Gamst, Anthony; Zand, Amir K; Heba, Elhamy; Loomba, Rohit; Schwimmer, Jeffrey; Middleton, Michael S; Sirlin, Claude B

2015-10-01

Determine intra- and inter-examination repeatability of magnitude-based magnetic resonance imaging (MRI-M), complex-based magnetic resonance imaging (MRI-C), and magnetic resonance spectroscopy (MRS) at 3T for estimating hepatic proton density fat fraction (PDFF), and using MRS as a reference, confirm MRI-M and MRI-C accuracy. Twenty-nine overweight and obese pediatric (n = 20) and adult (n = 9) subjects (23 male, 6 female) underwent three same-day 3T MR examinations. In each examination MRI-M, MRI-C, and single-voxel MRS were acquired three times. For each MRI acquisition, hepatic PDFF was estimated at the MRS voxel location. Intra- and inter-examination repeatability were assessed by computing standard deviations (SDs) and intra-class correlation coefficients (ICCs). Aggregate SD was computed for each method as the square root of the average of first repeat variances. MRI-M and MRI-C PDFF estimation accuracy was assessed using linear regression with MRS as a reference. For MRI-M, MRI-C, and MRS acquisitions, respectively, mean intra-examination SDs were 0.25%, 0.42%, and 0.49%; mean intra-examination ICCs were 0.999, 0.997, and 0.995; mean inter-examination SDs were 0.42%, 0.45%, and 0.46%; and inter-examination ICCs were 0.995, 0.992, and 0.990. Aggregate SD for each method was <0.9%. Using MRS as a reference, regression slope, intercept, average bias, and R (2), respectively, for MRI-M were 0.99%, 1.73%, 1.61%, and 0.986, and for MRI-C were 0.96%, 0.43%, 0.40%, and 0.991. MRI-M, MRI-C, and MRS showed high intra- and inter-examination hepatic PDFF estimation repeatability in overweight and obese subjects. Longitudinal hepatic PDFF change >1.8% (twice the maximum aggregate SD) may represent real change rather than measurement imprecision. Further research is needed to assess whether examinations performed on different days or with different MR technologists affect repeatability of MRS voxel placement and MRS-based PDFF measurements.

Intra- and inter-examination repeatability of magnetic resonance spectroscopy, magnitude-based MRI, and complex-based MRI for estimation of hepatic proton density fat fraction in overweight and obese children and adults

PubMed Central

Tyagi, Avishkar; Yeganeh, Omid; Levin, Yakir; Hooker, Jonathan C.; Hamilton, Gavin C.; Wolfson, Tanya; Gamst, Anthony; Zand, Amir K.; Heba, Elhamy; Loomba, Rohit; Schwimmer, Jeffrey; Middleton, Michael S.; Sirlin, Claude B.

2016-01-01

Purpose Determine intra- and inter-examination repeatability of magnitude-based magnetic resonance imaging (MRI-M), complex-based magnetic resonance imaging (MRI-C), and magnetic resonance spectroscopy (MRS) at 3T for estimating hepatic proton density fat fraction (PDFF), and using MRS as a reference, confirm MRI-M and MRI-C accuracy. Methods Twenty-nine overweight and obese pediatric (n = 20) and adult (n = 9) subjects (23 male, 6 female) underwent three same-day 3T MR examinations. In each examination MRI-M, MRI-C, and single-voxel MRS were acquired three times. For each MRI acquisition, hepatic PDFF was estimated at the MRS voxel location. Intra- and inter-examination repeatability were assessed by computing standard deviations (SDs) and intra-class correlation coefficients (ICCs). Aggregate SD was computed for each method as the square root of the average of first repeat variances. MRI-M and MRI-C PDFF estimation accuracy was assessed using linear regression with MRS as a reference. Results For MRI-M, MRI-C, and MRS acquisitions, respectively, mean intra-examination SDs were 0.25%, 0.42%, and 0.49%; mean intra-examination ICCs were 0.999, 0.997, and 0.995; mean inter-examination SDs were 0.42%, 0.45%, and 0.46%; and inter-examination ICCs were 0.995, 0.992, and 0.990. Aggregate SD for each method was <0.9%. Using MRS as a reference, regression slope, intercept, average bias, and R2, respectively, for MRI-M were 0.99%, 1.73%, 1.61%, and 0.986, and for MRI-C were 0.96%, 0.43%, 0.40%, and 0.991. Conclusion MRI-M, MRI-C, and MRS showed high intra- and inter-examination hepatic PDFF estimation repeatability in overweight and obese subjects. Longitudinal hepatic PDFF change >1.8% (twice the maximum aggregate SD) may represent real change rather than measurement imprecision. Further research is needed to assess whether examinations performed on different days or with different MR technologists affect repeatability of MRS voxel placement and MRS-based PDFF measurements

Cerebrospinal Fluid Shunting Complications in Children

PubMed Central

Hanak, Brian W.; Bonow, Robert H.; Harris, Carolyn A.; Browd, Samuel R.

2018-01-01

Although cerebrospinal fluid (CSF) shunt placement is the most common procedure performed by pediatric neurosurgeons, shunts remain among the most failure-prone life-sustaining medical devices implanted in modern medical practice. This article provides an overview of the mechanisms of CSF shunt failure for the 3 most commonly employed definitive CSF shunts in the practice of pediatric neurosurgery: ventriculoperitoneal, ventriculopleural, and ventriculoatrial. The text has been partitioned into the broad modes of shunt failure: obstruction, infection, mechanical shunt failure, overdrainage, and distal catheter site-specific failures. Clinical management strategies for the various modes of shunt failure are discussed as are research efforts directed towards reducing shunt complication rates. As it is unlikely that CSF shunting will become an obsolete procedure in the foreseeable future, it is incumbent on the pediatric neurosurgery community to maintain focused efforts to improve our understanding of and management strategies for shunt failure and shunt-related morbidity. PMID:28249297

Liver metastases from colorectal cancer: regional intra-arterial treatment following failure of systemic chemotherapy

PubMed Central

Cyjon, A; Neuman-Levin, M; Rakowsky, E; Greif, F; Belinky, A; Atar, E; Hardoff, R; Brenner, B; Sulkes, A

2001-01-01

This study was designed to determine response rate, survival and toxicity associated with combination chemotherapy delivered intra-arterially to liver in patients with hepatic metastases of colorectal origin refractory to standard systemic treatment. A total of 28 patients who failed prior systemic treatment with fluoropyrimidines received a median of 5 cycles of intra-arterial treatment consisting of 5-fluorouracil 700 mg/m2/d, leucovorin 120 mg/m2/d, and cisplatin 20 mg/m2/d for 5 consecutive days. Cycles were repeated at intervals of 5–6 weeks. A major response was achieved in 48% of patients: complete response in 8% and partial response in 40%. The median duration of response was 11.5 months. Median survival was 12 months at a median follow up of 12 months. On multivariate analysis, the only variables with a significant impact on survival were response to treatment and performance status. Toxicity was moderate: grades III–IV neutropenia occurred in 29% of patients. Most of the patients complained of fatigue lasting for a few days following each cycle. There were no cases of hepatobiliary toxicity. These findings indicate that regional intra-arterial treatment should be considered in selected patients with predominantly liver disease following failure of standard treatment. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11506487

Model of complete separation of the hepatic veins from the systemic venous system.

PubMed

Brizard, C P; Goussef, N; Chachques, J C; Carpentier, A F

2000-12-01

In patients undergoing a Fontan operation, partial diversion of the hepatic veins to the pulmonary venous atrium has been tried with various techniques. They failed because of the development of intrahepatic collaterals leading to an unacceptable right-to-left shunting. We postulate that to avoid the formation of intrahepatic collaterals, the totality of the liver has to be drained into the same pressure compartment. We have designed a model of cavopulmonary anastomosis in which a prosthetic conduit reproduces an azygos continuation, associated with the diversion of the totality of the hepatic venous return. This article reports on the early hemodynamics and the fate of the separation of the two venous compartments in long-term survivors. Eighteen goats were operated on; the pulmonary artery and hepatic vein pressures were recorded. During month 2, an opacification of the inferior vena cava and the cavopulmonary connection was performed. Between months 6 and 14, another opacification was performed, together with pressure recording at both ends of the conduit. Postoperatively the pulmonary artery pressure was pulsatile with a mean of 10 mm Hg and the hepatic vein pressure was 0 mm Hg. The first angiogram showed patent tubes with fast progression of the contrast. Throughout the inferior vena cava injection, there was no opacification of the portal or hepatic veins. The late study showed a narrowed conduit in all animals. During the injection, a collateral was injected, feeding into the inferior mesenteric vein. No collateral circulation could be seen draining directly into the liver. The median gradient between the two ends of the conduit was 11 mm Hg. The isolation of the entire hepatic venous drainage is feasible and efficient for the separation of two pressure compartments. No intrahepatic collaterals are observed with this model at short- or long-term follow-up. The separation of the hepatic venous drainage should persist without collateral circulation as long as

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

PubMed

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

2016-08-01

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

Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

PubMed

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.

Two signs indicative of successful access in nuclear medicine cerebrospinal fluid diversionary shunt studies.

PubMed

Bermo, Mohammed S; Khalatbari, Hedieh; Parisi, Marguerite T

2018-05-08

Successful shunt access is the first step in a properly performed nuclear medicine cerebrospinal fluid (CSF) shunt study. To determine the significance of the radiotracer configuration at the injection site during initial nuclear medicine CSF shunt imaging and the lack of early systemic radiotracer activity as predictors of successful shunt access. With Institutional Review Board approval, three nuclear medicine physicians performed a retrospective review of all consecutive CSF shunt studies performed in children at our institution in 2015. Antecedent nuclear medicine CSF shunt studies in these patients were also assessed and included in the review. The appearance of the reservoir site immediately after radiotracer injection was classified as either figure-of-eight or round/ovoid configuration. The presence or absence of early systemic distribution of the tracer on the 5-min static images was noted and separately evaluated. A total of 98 nuclear medicine ventriculoperitoneal CSF shunt studies were evaluated. Figure-of-eight configuration was identified in 87% of studies and, when present, had 93% sensitivity, 78% specificity, 92% accuracy, 98% positive predictive value (PPV) and 54% negative predictive value (NPV) as a predictor of successful shunt access. Early systemic activity was absent in 89 of 98 studies. Lack of early systemic distribution of the radiotracer had 98% sensitivity, 78% specificity, 96% accuracy, 98% PPV and 78% NPV as a predictor of successful shunt access. Figure-of-eight configuration in conjunction with the absence of early systemic tracer activity had 99% PPV for successful shunt access. Figure-of-eight configuration at the injection site or lack of early systemic radiotracer activity had moderate specificity for successful shunt access. Specificity and PPV significantly improved when both signs were combined in assessment.

Adaptive vibration suppression system: an iterative control law for a piezoelectric actuator shunted by a negative capacitor.

PubMed

Kodejska, Milos; Mokry, Pavel; Linhart, Vaclav; Vaclavik, Jan; Sluka, Tomas

2012-12-01

An adaptive system for the suppression of vibration transmission using a single piezoelectric actuator shunted by a negative capacitance circuit is presented. It is known that by using a negative-capacitance shunt, the spring constant of a piezoelectric actuator can be controlled to extreme values of zero or infinity. Because the value of spring constant controls a force transmitted through an elastic element, it is possible to achieve a reduction of transmissibility of vibrations through the use of a piezoelectric actuator by reducing its effective spring constant. Narrow frequency range and broad frequency range vibration isolation systems are analyzed, modeled, and experimentally investigated. The problem of high sensitivity of the vibration control system to varying operational conditions is resolved by applying an adaptive control to the circuit parameters of the negative capacitor. A control law that is based on the estimation of the value of the effective spring constant of a shunted piezoelectric actuator is presented. An adaptive system which achieves a self-adjustment of the negative capacitor parameters is presented. It is shown that such an arrangement allows the design of a simple electronic system which offers a great vibration isolation efficiency under variable vibration conditions.

Transjugular Intrahepatic Portosystemic Shunt Creation in Budd-Chiari Syndrome: Percutaneous Ultrasound-Guided Direct Simultaneous Puncture of the Portal Vein and Vena Cava

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyvat, Fatih, E-mail: boyvatf@yahoo.com; Aytekin, Cueneyt; Harman, Ali

Budd-Chiari syndrome (BCS) is an uncommon disorder that can be life-threatening, depending on the degree of hepatic venous outflow obstruction. Transjugular intrahepatic portosystemic shunt (TIPS) provides decompression of the congested liver but the hepatic vein obstruction makes the procedure more difficult. We describe a modified method that involved a single percutaneous puncture of the portal vein and inferior vena cava simultaneously for TIPS creation in a patient with BCS.

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

PubMed

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

2016-11-01

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

Evaluation and Management of Hepatic Encephalopathy: Current Status and Future Directions

PubMed Central

Suraweera, Duminda; Sundaram, Vinay; Saab, Sammy

2016-01-01

Hepatic encephalopathy is a spectrum of neurocognitive manifestations often seen in patients with liver injury or rarely in patients with portosystemic shunting without liver injury. It can be divided into minimal (covert) hepatic encephalopathy and overt hepatic encephalopathy, depending on the severity. Patients with hepatic encephalopathy have compromised clinical outcomes, decreased quality of life, and increased healthcare utilization, often resulting in a heavy financial and personal burden on caregivers. The diagnosis remains largely clinical, with the exclusion of possible other causes for the altered mental status. Current treatment strategies include nonabsorbable disaccharides and antibiotics. This review will focus on the diagnosis, management and clinical impact of hepatic encephalopathy. PMID:27377741

Arterioportal shunting, splanchnic capillary perfusion, and the effects of colloids during capnoperitoneum in neonatal and adolescent pigs.

PubMed

Kuebler, J F; Schukfeh, N; Vieten, G; Osthaus, W A; Huber, D; Dennhard, N; Suempelmann, R; Ure, B M; Metzelder, M L

2018-06-01

Clinical and experimental data indicate that neonates are sensitive to the CO 2 pneumoperitoneum. An impaired splanchnic perfusion during laparoscopy in adults has been reported. We recently confirmed that intravenous colloids improve macrocirculatory function in neonates. We aimed to determine the impact of CO 2 pneumoperitoneum on the perfusion of splanchnic organs in the young including effects of colloid application. Male piglets (n = 25) were divided into four groups: (1) neonatal controls, (2) neonates with crystalloid restitution, (3) neonates with colloidal restitution, and (4) adolescents with crystalloid restitution. Animals were ventilated and subjected to a 3-h, 10 mmHg CO 2 pneumoperitoneum followed by 2 h resuscitation. Hepatic, splanchnic, and arteriovenous shunt perfusion was assessed via central and portal venous catheters. Capillary organ flow was detected by fluorescent microspheres. The rate of bile flow was measured. The neonatal crystalloid group showed a significant decrease in the intestinal capillary perfusion at the end of the recovery period. This was not detectable in the adolescent and colloid group. There was a significant increase in microcirculatory arterioportal shunt flow during the CO 2 pneumoperitoneum in both neonatal groups but not in the sham and adolescent groups (p < 0.05). Hepatic arterial perfusion increased after insufflation in all groups and dropped during capnoperitoneum to levels of about 70% baseline. There was no significant impairment of splanchnic perfusion or bile flow as a result of the pneumoperitoneum in all groups. Capillary perfusion of the abdominal organs was stable during capnoperitoneum and recovery in adolescents and neonates with colloid restitution, but not with crystalloid restitution. Significant arterioportal shunting during capnoperitoneum could affect hepatic microcirculation in neonates. Our data confirm that moderate pressure capnoperitoneum has no major effect on the perfusion of

Asymptomatic Congenital Intrahepatic Portosystemic Shunt.

PubMed

Brown, Karen M; Hal, Hassan

2009-01-01

Congenital (spontaneous) intrahepatic portosystemic shunt is rare in the English literature. Most cases of portosystemic shunt occur after trauma, surgery, liver biopsy or as a result of chronic portal hypertension. Chronic shunting may result in encephalopathy, bleeding or hyperinsulinism. We report a case of an asymptomatic adult female with a presumed congenital intrahepatic portosystemic shunt and discuss the pertinent imaging findings and important key concepts related to this condition.

[Extracorporeal ventriculoatrial shunt with the use of one-way ball valve].

PubMed

Kubo, Shigeki; Takimoto, Hiroshi; Hosoi, Kazuki; Toyota, Shingo; Takakura, Shuji; Hayashi, Yasuhiro; Ueno, Masato; Morisako, Toshitaka; Karasawa, Jun; Ninaga, Hideo; Yoshimine, Toshiki

2002-04-01

We developed a simple system of an "extracorporeal" ventriculoatrial (VA) shunt using a one-way ball valve (Acty valve II, Kaneka Medix) to release the patient from postoperative constraint during the ventricular drainage. The system is constructed in such a way that the ventricular drainage tube is connected to the central venous catheter via a one-way valve. The CSF is regulated by using the valve and is diverted into the systemic circulation as in the conventional ventriculoatrial shunt. After 2 or 3 weeks of CSF diversion through the extracorporeal VA shunt, a ventriculoperitoneal shunt is placed if hydrocephalus is apparent by temporary occlusion of the system. We applied this system to 4 patients with hydrocephalus, and we found it useful and free from adverse effects. The patient was freed from physical constraint involved in conventional ventricular drainage and an effective program of early rehabilitation was able to be started.

Eculizumab in paroxysmal nocturnal hemoglobinuria with Budd-Chiari syndrome progressing despite anticoagulation

PubMed Central

2012-01-01

Paroxysmal nocturnal hemoglobinuria (PNH) is a progressive, life-threatening disorder characterized by chronic intravascular hemolysis caused by uncontrolled complement activation. Hepatic vein thrombosis (Budd-Chiari syndrome) is common in PNH patients. This case report describes the response to eculizumab (a humanized monoclonal antibody that inhibits terminal complement activation) in a 25-year-old male with progressive liver function deterioration despite standard anticoagulation therapy and transjugular intrahepatic porto-systemic shunt. The patient presented with anemia, severe thrombocytopenia, headache, abdominal pain, and distention. He was diagnosed with PNH, cerebral vein thrombosis, and Budd-Chiari syndrome. Despite adequate anticoagulation, diuretic administration, and placement of a transjugular shunt, additional thrombotic events and progressive liver damage were observed. Eculizumab therapy was initiated, resulting in rapid blockade of intravascular hemolysis, increased platelet counts, ascites resolution, and liver function recovery, all of which are presently sustained. Since starting eculizumab the patient has had no further thrombotic events and his quality of life has dramatically improved. This is the first report to confirm the role of complement-mediated injury in the progression of Budd-Chiari syndrome in a patient with PNH. This case shows that terminal complement blockade with eculizumab can reverse progressive thromboses and hepatic failure that is unresponsive to anticoagulation therapy and suggests that early initiation of eculizumab should be included in the therapeutic regimen of patients with PNH-related Budd-Chiari syndrome. PMID:23210433

To shunt or not to shunt? An experimental study comparing temporary vascular shunts and venous ligation as damage control techniques for vascular trauma.

PubMed

Marinho de Oliveira Góes Junior, Adenauer; de Campos Vieira Abib, Simone; de Seixas Alves, Maria Teresa; Venerando da Silva Ferreira, Paulo Sérgio; Carvalho de Andrade, Mariseth

2014-04-01

To evaluate vascular flow through temporary vascular shunts inserted into peripheral arteries and veins and the repercussion, on the arterial perfusion, of venous ligation and venous shunt insertion in an experimental model for damage control. Experimental study in pigs. Animals were distributed in 5 groups: group 1, right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2, right EIA shunting and right EIV shunting; group 3, right EIV ligation; group 4, right EIV shunting; group 5, no vascular shunting and no venous ligation. Flowmeters were used to measure vascular flow on right and left external iliac vessels, and blood samples were collected from the EIVs for biochemical analysis. A right anterior limb biopsy was performed before shock. Hemorrhagic shock was induced through the external right jugular vein, until the vascular flow through right iliac external artery shunt or right iliac external vein shunt (group 4) ceased or until the animal's death. After the end of the experiments, biopsies of bilateral hind limb were obtained for histologic analysis. For statistical analysis, Microsoft Office Excel 2007 and BioEstat 5.0 (2007) were used. In the absence of hemorrhagic shock, venous ligation (group 1) was associated with a 38.8% reduction (P < 0.05) and venous shunting with a 28.4% reduction on the vascular flow through the arterial shunt. When associated with hemorrhagic shock, the mean vascular flow on the right EIA was 13 mL/min and on the left EIA was 41.2 mL/min; on group 2, the right EIA flow was 8.5 mL/min and the left EIA flow was 8.1 mL/min. When associated with hemorrhagic shock, the pO2 was 25.8 mm Hg on right EIV and 33.8 mm Hg on the left EIV for group 1 (P < 0.05), whereas for group 2, the pO2 was 22.6 mm Hg on right EIV and 22.8 mm Hg on the left EIV. On group 1, serum potassium was 3.84 mEq/L on the right EIV and 3.96 mEq/L on the left EIV, whereas on group 2, it was 7.1 mEq/L on the right EIV and 5.88 m

Noncirrhotic Extrahepatic Portosystemic Shunt Causing Adult-Onset Encephalopathy Treated with Endovascular Closure

PubMed Central

Elnekave, Eldad; Belenky, Eugenia; Van der Veer, Lindsley

2015-01-01

A 54-year-old woman presented with a six-month history of episodic confusion and progressive ataxia. A comprehensive metabolic panel was notable for elevated values of alkaline phosphatase (161 U/L), total bilirubin (1.5 mg/dL), and serum ammonia of 300 umol/L (normal range 9–47). Hepatitis panel, relevant serological tests, tumor markers (CA-19-9, CEA), and urea cycle enzyme studies were unrevealing. Lactulose and rifaximin therapy failed to normalize serum ammonia levels. Imaging revealed a structural vascular abnormality communicating between an enlarged inferior mesenteric vein and the left renal vein, measuring 16 mm in greatest diameter. The diagnosis of congenital extrahepatic portosystemic shunt was made and endovascular shunt closure was performed using a 22 mm Amplatzer II vascular plug. Within a day, serum ammonia levels normalized. Lactulose and rifaximin were discontinued, and confusion and ataxia resolved. PMID:26199783

Simulation model for port shunting yards

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

Congenital intrahepatic portohepatic venous shunt: treatment with coil embolisation.

PubMed

Kim, I O; Cheon, J E; Kim, W S; Chung, J W; Yeon, K M; Yoo, S J; Seo, J K; Choi, J H

2000-05-01

Congenital abnormalities of the portal venous system are rare. There are few radiological descriptions of intrahepatic portosystemic venous shunt detected in the perinatal period. We report a congenital portosystemic shunt that was detected by US and treated with coil embolisation in the neonatal period.

Congenital intrahepatic portosystemic shunt: prenatal diagnosis and possible influence on fetal growth.

PubMed

Delle Chiaie, L; Neuberger, P; Von Kalle, T

2008-08-01

Congenital intrahepatic portosystemic shunts (IPSS) are abnormal vascular communications within the liver between branches of the portal vein and the hepatic veins. They have been recognized as an important disorder in children and should be differentiated from metabolic diseases, the symptoms of which may be similar. Several cases of prenatal diagnosis of abnormalities of the fetal venous system have been described in the literature, but the significance and prognosis of isolated congenital IPSS in prenatal life have not been reported and have only been derived from children. We present a case of congenital IPSS in which there was severe intrauterine growth restriction with a concomitant atypical fetal Doppler pattern. Findings on Doppler ultrasound indicate that the prenatal diagnosis of congenital IPSS is now feasible. (c) 2008 ISUOG. Published by John Wiley & Sons, Ltd.

Cerebrospinal fluid eosinophilia and sterile shunt malfunction.

PubMed

Traynelis, V C; Powell, R G; Koss, W; Schochet, S S; Kaufman, H H

1988-11-01

Cerebrospinal fluid (CSF) eosinophilia is a rare finding most often associated with central nervous system inflammatory processes, including parasitic, bacterial, and mycotic infections. It has also been seen as an allergic phenomenon. We present two cases of CSF eosinophilia occurring concurrently with sterile shunt malfunction. We speculate that CSF eosinophilia in our patients might have resulted from an allergic response to a foreign material such as suture, surgical glove powder, hair, cotton fibers, antibiotics, or silicone rubber. The incidence of sterile CSF eosinophilia after shunting is not known. Information concerning the role of eosinophilia in the development of shunt malfunctions is also lacking. An increased awareness of this possibility and further investigation are warranted.

Novel type of peritoneocentesis trocar-assisted distal ventriculoperitoneal shunt placement with supervision via a one-port laparoscope

PubMed Central

Wang, Guangming; Yu, Jinlu; Luan, Yongxin; Han, Yanwu; Fu, Shuanglin

2017-01-01

Ventriculoperitoneal shunts (VPS) are the primary treatment for hydrocephalus and are associated with a high risk of complications, specifically in patients who are obese or have abdominal adhesions or shunt revisions. The present study describes the use of a novel type of peritoneal catheter peritoneocentesis trocar insertion with the assistance of a one-port laparoscope. A total of 36 patients with hydrocephalus underwent this novel type of peritoneocentesis trocar-assisted VPS. The distal shunt catheter was placed into the right subdiaphragmatic space and the catheter was traversed through a single hole drilled through the liver falciform ligament. The duration of the laparoscopic surgery ranged from 6–18 min (mean 10.4±1.6 min). No shunt-related infections or catheter malfunctions or injuries to the intra-abdominal organs occurred. The total abdominal incision length was 1.0 cm (0.5+0.5 cm). No laparoscopy-related complications were observed during follow-up assessments. The novel approach used in the current study is very easy to perform, and this method may significantly reduce the risk of malfunction complications. The presented method also has the advantages of reduced trauma and a simpler surgery. The current study indicated that this simple, minimally invasive procedure was beneficial for patients with hydrocephalus, specifically in cases of patients with obesity, peritoneal adhesions or shunt revisions. PMID:29042927

Novel type of peritoneocentesis trocar-assisted distal ventriculoperitoneal shunt placement with supervision via a one-port laparoscope.

PubMed

Wang, Guangming; Yu, Jinlu; Luan, Yongxin; Han, Yanwu; Fu, Shuanglin

2017-10-01

Ventriculoperitoneal shunts (VPS) are the primary treatment for hydrocephalus and are associated with a high risk of complications, specifically in patients who are obese or have abdominal adhesions or shunt revisions. The present study describes the use of a novel type of peritoneal catheter peritoneocentesis trocar insertion with the assistance of a one-port laparoscope. A total of 36 patients with hydrocephalus underwent this novel type of peritoneocentesis trocar-assisted VPS. The distal shunt catheter was placed into the right subdiaphragmatic space and the catheter was traversed through a single hole drilled through the liver falciform ligament. The duration of the laparoscopic surgery ranged from 6-18 min (mean 10.4±1.6 min). No shunt-related infections or catheter malfunctions or injuries to the intra-abdominal organs occurred. The total abdominal incision length was 1.0 cm (0.5+0.5 cm). No laparoscopy-related complications were observed during follow-up assessments. The novel approach used in the current study is very easy to perform, and this method may significantly reduce the risk of malfunction complications. The presented method also has the advantages of reduced trauma and a simpler surgery. The current study indicated that this simple, minimally invasive procedure was beneficial for patients with hydrocephalus, specifically in cases of patients with obesity, peritoneal adhesions or shunt revisions.

[Pulsatile total cavopulmonary shunt for hypoplastic right heart syndrome with abnormal systemic venous return--a case report].

PubMed

Oiwa, H; Kawauchi, M; Chikada, M; Yagyu, K; Kotsuka, Y; Furuse, A

1995-01-01

A pulsatile total cavopulmonary shunt was successfully performed on a 5-year-old girl with hypoplastic right heart syndrome associated with abnormal systemic venous return; at the same time, modified mitral valve replacement was performed for mitral regurgitation. The right atrium, tricuspid valve and right ventricle were all extremely dimunitive. The diameter of the tricuspid valve was 50% of normal and the volume of the right ventricle was 8.6% of normal. In addition, there were severe subpumonary stenosis, a restrictive ventricular septal defect (VSD) and an atrial septal defect (ASD). The bilateral superior venae cavae (SVCs) and the hepatic vein drained to the left atrium, and the inferior vena cava was infrahepatically interrupted with a hemiazygos connection to the left superior vena cava. At the operation, each SVC was anastomosed end-to-side to each branch of the pulmonary artery (PA). The restrictive ventricular septal defect and stenotic subpulmonary lesion were left. The diameter of the ASD was reduced from 12 mm to 7 mm. The main PA was neither divided nor banded. The pulsatile blood flow from the left heart to the PA was regurated by a native restrictive VSD and stenotic subpulmonary lesion, and that from the right heart via the ASD was limited by reducing the size of the ASD. These described anatomic arrangements produced adequate antegrade pulsatile flow in the PA, which might prevent the development of pulmonary arteriovenous fistulae and, besides permit transfer of drainage of the hepatic vein from the left to the right atrium via the ASD in future.

Hepatic encephalopathy in a liver transplant recipient with stable liver function.

PubMed

Arab, Juan Pablo; Meneses, Luis; Pérez, Rosa M; Arrese, Marco; Benítez, Carlos

2013-04-01

Postshunt hepatic encephalopathy after liver transplantation (LT) is an infrequent condition and is commonly associated with portal occlusion or stenosis and the presence of a patent portosystemic shunt. Portal vein stenosis (PVS) or thrombosis (PVT) are uncommon complications after LT. The overall frequency of both complications is reported to be less than 3%. When PVS or PVT develop early after LT, the occlusion of the portal vein can have catastrophic consequences to the graft including acute liver failure and graft loss. Late PVT/PVS are asymptomatic in approximately 50% of the cases and mainly diagnosed by a routine ultrasound. Symptomatic postshunt hepatic encephalopathy (HE) is a very infrequent condition after LT that has been scarcely reported in the literature. We present here the case of a liver recipient with normal graft function who presented with hepatic encephalopathy 3 months after LT with stable liver function but a severe portal stenosis and the presence of a spontaneous portosystemic shunt whose successful endovascular treatment was followed by the complete resolution of the HE.

In vitro flow measurements in ion sputtered hydrocephalus shunts

NASA Technical Reports Server (NTRS)

Cho, Y. I.; Back, L. H.

1989-01-01

This paper describes an experimental procedure for accurate measurements of the pressure-drop/flow rate relationship in hydrocephalus shunts. Using a fish-hook arrangement, small flow rates in a perforated ion-sputtered Teflon microtubule were measured in vitro in a pressured system and were correlated with pressure in the system. Results indicate that appropriate drainage rates could be obtained in the physiological range for hydrocephalus shunts.

Laparoscopic treatment of abdominal complications following ventriculoperitoneal shunt

PubMed Central

Grigorean, VT; Onose, G; Popescu, M; Strambu, V; Sandu, AM

2009-01-01

The aim of this study is the evaluation of laparoscopic treatment in abdominal complications following ventriculoperitoneal (VP) shunt. Methods: We report a retrospective study including 17 patients with abdominal complications secondary to VP shunt for hydrocephalus, laparoscopically treated in our department, between 2000 and 2007. Results: Patients' age ranged from 1 to 72 years old (mean age 25.8 years old). Male: female ratio was 1.4. Abdominal complications encountered were: shunt disconnection with intraperitoneal distal catheter migration 47.05% (8/17), infections 23.52% (4/17) such as abscesses and peritonitis, pseudocysts 11.76% (2/17), CSF ascites 5.88% (1/17), inguinal hernia 5.88% (1/17), and shunt malfunction due to excessive length of intraperitoneal tube 5.88% (1/17). Free–disease interval varies from 1 day to 21 years, depending on the type of complication, short in peritoneal irritation syndrome and abscesses (days) and long in ascites, pseudocysts(months– years). Laparoscopic treatment was: extraction of the foreign body in shunt disconnection with intraperitoneal distal catheter migration, evacuation, debridement, lavage and drainage for pseudocysts, abscess and peritonitis, shortening of the tube in shunt malfunction due to excessive length of intraperitoneal tube a nd hernioraphy. One diagnostic laparoscopy was performed in a peritoneal irritation syndrome, which found only CSF ascites. There were no conversions to open surgery. The overall mortality was of 5.88% and postoperative morbidity was of 11.76%. In 7 patients operated for abscesses, peritonitis, pseudocysts, and CSF ascites the shunting system was converted in to a ventriculocardiac shunt. Conclusions: Abdominal complication following VP shunt can be successfully performed laparoscopically. Abdominal surgery required, in selected cases, the repositioning of the distal catheter, frequently as a ventriculocardiac shunt. There are abdominal complications with no indication of

Histological findings of failed gold micro shunts in primary open-angle glaucoma.

PubMed

Agnifili, Luca; Costagliola, Ciro; Figus, Michele; Iezzi, Giovanna; Piattelli, Adriano; Carpineto, Paolo; Mastropasqua, Rodolfo; Nardi, Marco; Mastropasqua, Leonardo

2012-01-01

To describe the histological features of failed gold micro shunts (GMS) in unsuccessful implantations for refractory primary open-angle glaucoma (POAG). This was an interventional case series study. Five eyes of five glaucomatous patients with unsuccessful GMS implantation underwent shunt removal. Each device was sectioned into three portions: proximal or anterior chamber (AC) portion, middle or scleral portion and distal or suprachoroidal (SC) portion. The histological analysis was performed throughout the whole extent of the shunt, describing both the inner spaces and the outer surface. At the moment of removal all devices were correctly located into the SC space and in AC, with the exception of a case presenting corneal endothelial contact. The mean intra-ocular pressure before GMS removal was 30.4 ± 5.3 mmHg, and the mean time of GMS removal after implantation was 6.8 ± 2.5 months. No significant histological differences were documented among the five analyzed devices. The main feature was the presence of a thick connective capsule-like reaction surrounding both the proximal and distal ends and invading the posterior and anterior grid holes, whereas a more loosely arranged connective tissue was observed within the inner channels. Signs of surface fibrosis of the middle-scleral portion and inflammatory cell infiltration of the device were not documented in any of the cases. Failed GMS implantations presented connective tissue filling all the inner spaces and creating a thick fibrotic capsule surrounding the ends of the device. This modification isolated the GMS from the AC and SC space, impeding aqueous flows throughout the shunt.

Outcome of shunting in idiopathic normal-pressure hydrocephalus and the value of outcome assessment in shunted patients.

PubMed

Klinge, Petra; Marmarou, Anthony; Bergsneider, Marvin; Relkin, Norman; Black, Peter McL

2005-09-01

To develop guidelines for assessing shunt outcome in patients with idiopathic normal-pressure hydrocephalus (INPH). To date, the literature available on this topic has been marked by disparate definitions of clinical improvement, varying postoperative follow-up protocols and periods, and substantial differences in the postoperative management. Because specific criteria for defining clinical improvement are seldom reported, conclusions drawn about shunt outcome may be subjective. A MEDLINE search back to 1966 was undertaken using the query NPH, normal-pressure hydrocephalus, shunting, shunt treatment, shunt response, outcome, and clinical outcome. The criteria for selection were studies that included INPH from 1966 to the present in which the outcome of INPH was reported in patient groups of 20 or more. To date, there is no standard for outcome assessment of shunt treatment in INPH. The variable improvement rates reported are not only because of different criteria for selection of patients but also because of different postoperative assessment procedures and follow-up intervals. Studies that have established fixed protocols for follow-up have shown that short- and long-term periods after shunting are determined by many factors. Whereas short-term results were more likely to be influenced by shunt-associated risks, long-term results were independent of factors inherent to the shunt procedure and shunt complications, i.e., death and morbidity related to concomitant cerebrovascular and vascular diseases. Studies have shown that beyond 1 year after surgery, these factors definitely influence the clinical effect of shunting, making the 1-year postshunt period a potential determinant of the shunt outcome. Guidelines for outcome assessment were developed on the basis of the available evidence and consensus of expert opinion.

Shunting for normal pressure hydrocephalus (NPH).

PubMed

Esmonde, T; Cooke, S

2002-01-01

Since the condition was first described in 1965, the syndrome of normal pressure hydrocephalus (NPH) has conventionally been managed by placement of a cerebrospinal fluid (CSF) shunt. To determine the effectiveness of shunting procedures in promoting stability or improvement in the neurological symptoms and signs of NPH. The trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 26 June 2001 using the terms 'shunt*' and 'normal pressure hydrocephalus'. Studies included for analysis were those involving the placement of a CSF shunt for the treatment of NPH as part of a randomized controlled trial. No data matching the selection criteria were found. No randomized controlled trials of shunt placement versus no shunt were found. There is no evidence to indicate whether placement of a shunt is effective in the management of NPH.

21 CFR 870.3535 - Intra-aortic balloon and control system

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intra-aortic balloon and control system 870.3535... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3535 Intra-aortic balloon and control system (a) Identification. A intra-aortic balloon and control system is a device that...

21 CFR 870.3535 - Intra-aortic balloon and control system

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intra-aortic balloon and control system 870.3535... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3535 Intra-aortic balloon and control system (a) Identification. A intra-aortic balloon and control system is a device that...

Programmable valve shunts: are they really better?

PubMed

Kataria, Rashim; Kumar, Vimal; Mehta, Veer Singh

2012-01-01

Programmable valve shunts allows selection of opening pressure of shunt valve. In the presented article, a unique complication pertaining to programmable shunts has been discussed. A 5-year-old boy who had tectal plate low grade glioma with obstructive hydrocephalus was managed with Codman programmable ventriculoperitoneal shunt. There was a spontaneous change in the opening pressure of the shunt valve leading to shunt malfunction. Routinely used household appliances produce a magnetic field strong enough to cause change in the setting of shunt valve pressure and may lead to valve malfunction. Other causes of programmable valve malfunction also discussed.

A method for quickly and exactly extracting hepatic vein

NASA Astrophysics Data System (ADS)

Xiong, Qing; Yuan, Rong; Wang, Luyao; Wang, Yanchun; Li, Zhen; Hu, Daoyu; Xie, Qingguo

2013-02-01

It is of vital importance that providing detailed and accurate information about hepatic vein (HV) for liver surgery planning, such as pre-operative planning of living donor liver transplantation (LDLT). Due to the different blood flow rate of intra-hepatic vascular systems and the restrictions of CT scan, it is common that HV and hepatic portal vein (HPV) are both filled with contrast medium during the scan and in high intensity in the hepatic venous phase images. As a result, the HV segmentation result obtained from the hepatic venous phase images is always contaminated by HPV which makes accurate HV modeling difficult. In this paper, we proposed a method for quick and accurate HV extraction. Based on the topological structure of intra-hepatic vessels, we analyzed the anatomical features of HV and HPV. According to the analysis, three conditions were presented to identify the nodes that connect HV with HPV in the topological structure, and thus to distinguish HV from HPV. The method costs less than one minute to extract HV and provides a correct and detailed HV model even with variations in vessels. Evaluated by two experienced radiologists, the accuracy of the HV model obtained from our method is over 97%. In the following work, we will extend our work to a comprehensive clinical evaluation and apply this method to actual LDLT surgical planning.

Segmental liver ischemia/infarction after elective transjugular intrahepatic portosystemic shunt creation: clinical outcomes in 10 patients.

PubMed

Lopera, Jorge E; Katabathina, Venkata; Bosworth, Brian; Garg, Deepak; Kroma, Ghazwan; Garza-Berlanga, Andres; Suri, Rajeev; Wholey, Michael

2015-06-01

To determine the clinical significance and potential mechanisms of segmental liver ischemia and infarction following elective creation of a transjugular intrahepatic portosystemic shunt (TIPS). A retrospective review of 374 elective TIPS creations between March 2006 and September 2014 was performed, yielding 77 contrast-enhanced scans for review. Patients with imaging evidence of segmental perfusion defects were identified. Model for End-stage Liver Disease scores, liver volume, and percentage of liver ischemia/infarct were calculated. Clinical outcomes after TIPS creation were reviewed. Ten patients showed segmental liver ischemia/infarction on contrast-enhanced imaging after elective TIPS creation. Associated imaging findings included thrombosis of the posterior division (n = 7) and anterior division (n = 3) of the right portal vein (PV). The right hepatic vein was thrombosed in 5 patients, as was the middle hepatic vein in 3 and the left hepatic vein in 1. One patient had acute thrombosis of the shunt and main PV. Three patients developed acute liver failure: 2 died within 30 days and 1 required emergent liver transplantation. One patient died of acute renal failure 20 days after TIPS creation. A large infarct in a transplant recipient resulted in biloma formation. Five patients survived without additional interventions with follow-up times ranging from 3 months to 5 years. Segmental perfusion defects are not an uncommon imaging finding after elective TIPS creation. Segmental ischemia was associated with thrombosis of major branches of the PVs and often of the hepatic veins. Clinical outcomes varied significantly, from transient problems to acute liver failure with high mortality rates. Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.

Congenital portosystemic shunts in children: recognition, evaluation, and management.

PubMed

Bernard, O; Franchi-Abella, S; Branchereau, S; Pariente, D; Gauthier, F; Jacquemin, E

2012-11-01

Congenital portosystemic shunts are present in one in 30,000 children. Among the associated risks of severe complications are neonatal cholestasis, benign and malignant liver tumors, hepatopulmonary syndrome, portopulmonary hypertension, and encephalopathy. They can be detected on prenatal ultrasonograms, during the investigation of a positive galactosemia screening test in neonates or of a complication, or be found fortuitously on an abdominal ultrasound. Small intrahepatic shunts may resolve spontaneously within one year of age, but other shunts such as extrahepatic, persistent ductus venosus or persisting intrahepatic shunts, must be closed in one or two steps, by interventional radiology techniques or surgically. The plasticity of the intrahepatic portal system allows revascularization of the liver after shunt closure, even when no intrahepatic portal structures can be detected on imaging studies. This leaves little or no place for liver transplantation in the management of these children. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Magnetic Resonance Spectroscopy for Evaluating Portal-Systemic Encephalopathy in Patients with Chronic Hepatic Schistosomiasis Japonicum.

PubMed

Li, Ying; Mei, Lihong; Qiang, Jinwei; Ju, Shuai; Zhao, Shuhui

2016-12-01

Portal-systemic encephalopathy (PSE) is classified as type B hepatic encephalopathy. Portal-systemic shunting rather than liver dysfunction is the main cause of PSE in chronic hepatic schistosomiasis japonicum (HSJ) patients. Owing to lack of detectable evidence of intrinsic liver disease, chronic HSJ patients with PSE are frequently clinically undetected or misdiagnosed, especially chronic HSJ patients with covert PSE (subclinical encephalopathy). In this study, we investigated whether magnetic resonance spectroscopy (MRS) could be a useful tool for diagnosing PSE in chronic HSJ patients. Magnetic resonance (MR) T1-weighted imaging, diffusion-weighted imaging, and MRS were performed in 41 chronic HSJ patients with suspected PSE and in 21 age-matched controls. The T1 signal intensity index (T1SI) and apparent diffusion coefficient (ADC) value were obtained in the Globus pallidus. Liver function was also investigated via serum ammonia and liver function tests. Higher T1SI and ADC values, increased lactate and glutamine levels, and decreased myo-inositol were found in the bilateral Globus pallidus in chronic HSJ patients with PSE. No significantly abnormal serum ammonia or liver function tests were observed in chronic HSJ patients with PSE. On the basis of these findings, we propose a diagnostic procedure for PSE in chronic HSJ patients. This study reveals that MRS can be useful for diagnosing PSE in chronic HSJ patients.

Design and simulation of RF MEMS SPST shunt and SPDT shunt-shunt switches for X-band and Ku-band applications

NASA Astrophysics Data System (ADS)

Lenka, Manas K.; Sharma, Amit; Sharma, Jaibir; DasGupta, Amitava

2012-10-01

This paper describes the design and simulation of RF MEMS SPST shunt and SPDT shunt-shunt switches with modified coplanar waveguide (CPW) configuration for X-band and Ku-band applications exhibiting high isolation and low insertion loss. By modifying the basic CPW structure for a six-strip membrane having length 720 μm, the resonant frequency can be reduced from 33.5 GHz to 13.5 GHz with isolation as high as -30 dB(-63 dB at resonant frequency) in Ku-band. Similar results are also found in case SPST and SPDT switches with other membrane types.

Surgical disconnection of patent paraumbilical vein in refractory hepatic encephalopathy.

PubMed

Ishikawa, Yoshinori; Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Bando, Koichi; Mizuguchi, Yoshiaki; Kakinuma, Daisuke; Kanda, Tomohiro; Akimaru, Koho; Tajiri, Takashi

2008-06-01

Refractory hepatic encephalopathy (HE) frequently develops in patients with cirrhosis and portal-systemic shunt. Recently, patients with refractory HE associated with portal-systemic shunt have been treated with interventional radiology. We describe a promising new treatment for portal-systemic shunt, ligation of the patent paraumbilical vein (PUV) after partial splenic embolization, in patients with refractory HE. Four patients with cirrhosis (3 women and 1 man; mean age, 56 years) and refractory HE due to a patent PUV were studied. Patency of the PUV had recurred in 1 patient after primary occlusion by interventional radiological procedures. The Child-Pugh class was B in 2 patients and C in 2. Before the present treatment, all patients had been hospitalized at least 3 times because of recurrent HE. Partial splenic embolization was performed in all patients to decrease portal venous pressure before surgery. Surgical ligation of the patent PUV was performed under epidural anesthesia. The patent PUV was carefully skeletonized and doubly ligated. Esophageal varices were evaluated with upper gastrointestinal endoscopy before and after surgery. The mean follow-up duration was 15.8 months. After ligation, there were no clinically significant complications. Esophageal varices were unchanged. The serum ammonia level was higher before surgery (162.3 +/- 56.4 mug/dL, mean +/- SD) than after surgery (41.8 +/- 20.2 mug/dL; p=0.0299). No patient had symptoms of HE. Ligation of the patent PUV is an effective treatment for patients with refractory HE.

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

PubMed

Roth, Jonathan; Constantini, Shlomi; Kesler, Anat

2015-01-01

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

Gravitational shunt units may cause under-drainage in bedridden patients.

PubMed

Kaestner, S; Kruschat, T; Nitzsche, N; Deinsberger, W

2009-03-01

Implantation of a shunt in a hydrocephalic patient still carries a risk of complications such as over-drainage and under-drainage. Gravitational shunt units are especially designed to minimize the problem of over-drainage. Nevertheless, these valves carry a risk of under-drainage. The best choice of valve for a patient is still challenging. The purpose of this survey was to identify in which patients a gravitational shunt valve is liable to lead to under-drainage. Patients with hydrocephalus entered prospectively into a data base were reviewed retrospectively. The patients were treated between January 2006 to the end of Feb 2007 and those experiencing under- or over-drainage were identified. Thirty-five ventriculo-peritoneal shunt systems were implanted in adult patients. The cause of the hydrocephalus was: normal pressure hydrocephalus in 18 patients, post-haemorrhagic following subarachnoid or intracerebral haemorrhage in 11, associated with a tumour in four and followed a head injury in two patients. Three different valves were used: an adjustable shunt valve with gravitational unit (Pro-GAV 0-20/25 in 21 patients), a gravitational shunt valve with fixed opening pressure (GAV 5/30 in nine patients) and an adjustable differential valve (Hakim medos in five patients). Four patients developed severe, valve-related under-drainage. Each had received a gravitational shunt valve and all were bedridden. In two of these patients it was necessary to change the valve. One patient who had received a differential valve, after regaining mobility developed severe over-drainage with bilateral subdural haematomas. Over-drainage was not seen in long-term bedridden patients with a differential shunt valve. If a bedridden patient with a gravitational shunt valve system lies with a slightly elevated head, this leads to activation of the gravitational unit and this may cause under drainage. As a result, we advise not using an anti-siphon devices in a patient who is bedridden for a

Postprandial hyperinsulinaemic hypoglycaemia secondary to a congenital portosystemic shunt.

PubMed

Senniappan, Senthil; Pitt, Katherine; Shah, Pratik; Arya, Ved; Jaiswal, Sanjay; Haddad, Munther; Hind, Jonathan; Dhawan, Anil; Davenport, Mark; Hussain, Khalid

2015-01-01

Portosystemic shunts (PSS) are abnormal vascular connections between the portal vein or its tributaries and the systemic vein that allow mesenteric blood to reach the systemic circulation without first passing through the liver. PSS can be associated with various syndromes and can lead to serious complications. We report a rare case of a child with PSS and recurrent hypoglycaemia. A 20-month-old girl with Down's syndrome presented with recurrent hypoglycaemic episodes. She had multiple anomalies including a ventricular septal defect, oesophageal atresia and tracheo-esophageal fistula, gastro-oesophageal reflux, and conjugated hyperbilirubinaemia. The initial investigations suggested hyperinsulinaemic hypoglycaemia (HH). She did not respond to diazoxide. An oral glucose tolerance test suggested postprandial HH. Further vascular imaging showed a side-to-side portocaval shunt (Abernethy malformation) with relative hypoperfusion of the liver. Hypoglycaemia resolved following surgical closure of the portocaval shunt. PSS can rarely be associated with HH, possibly due to lack of insulin degradation in the liver. Surgical closure of the shunt resolves the hypoglycaemia. © 2015 S. Karger AG, Basel.

49 CFR 236.838 - Wire, shunt.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Wire, shunt. 236.838 Section 236.838 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Wire, shunt. A wire forming part of a shunt circuit. ...

49 CFR 236.838 - Wire, shunt.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Wire, shunt. 236.838 Section 236.838 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Wire, shunt. A wire forming part of a shunt circuit. ...

Use of concomitant variceal embolization and prophylactic antiplatelet/anticoagulative in transjugular intrahepatic portosystemic shunting: A retrospective study of 182 cirrhotic portal hypertension patients.

PubMed

Tang, Yingmei; Zheng, Sheng; Yang, Jinhui; Bao, Weimin; Yang, Lihong; Li, Yingchun; Xu, Ying; Yang, Jing; Tong, Yuyun; Gao, Jinhang; Tang, Chengwei

2017-12-01

Transjugular intrahepatic portosystemic shunting (TIPS) is an effective treatment modality for refractory variceal bleeding and ascites in patients with cirrhotic portal hypertension (CPH). Variceal rebleeding and shunt dysfunction are major post-TIPS morbidities. This study aimed to retrospectively evaluate the effectiveness and safety of use of concomitant variceal embolization and prophylactic antiplatelet/anticoagulative in patients with CPH undergoing TIPS. Between October 2006 and October 2011, 182 patients with CPH were retrospectively and consecutively hospitalized for elective TIPS with Fluency stenting. Concomitant variceal embolization was given after establishing the shunt. Subcutaneous heparin was given after TIPS and replaced by oral clopidogrel, aspirin, or warfarin for at least 6 months. Main outcome measures included shunt patency rate, recurrence of CPH (rebleeding and/or refractory ascites), hepatic encephalopathy (HE) frequency, and post-TIPS survival. The cumulative primary patency rate was 96%, 94%, 90%, 88%, and 88% at 6, 12, 24, 36, and 48 months, respectively. Shunt stenosis occurred in 16 (9%) patients, gastrointestinal (GI) rebleeding in 32 (17.5%) patients, recurrence of refractory ascites 44 (48%) patients, HE in 42 (23%) patients, and death in 36 (20%) patients during the follow-up period. Use of concomitant variceal embolization and prophylactic antiplatelet/anticoagulative was associated with a favorable shunt patency and a low risk of GI rebleeding.

Elemental Study on Auscultaiting Diagnosis Support System of Hemodialysis Shunt Stenosis by ANN

NASA Astrophysics Data System (ADS)

Suzuki, Yutaka; Fukasawa, Mizuya; Mori, Takahiro; Sakata, Osamu; Hattori, Asobu; Kato, Takaya

It is desired to detect stenosis at an early stage to use hemodailysis shunt for longer time. Stethoscope auscultation of vascular murmurs is useful noninvasive diagnostic approach, but an experienced expert operator is necessary. Some experts often say that the high-pitch murmurs exist if the shunt becomes stenosed, and some studies report that there are some features detected at high frequency by time-frequency analysis. However, some of the murmurs are difficult to detect, and the final judgment is difficult. This study proposes a new diagnosis support system to screen stenosis by using vascular murmurs. The system is performed using artificial neural networks (ANN) with the analyzed frequency data by maximum entropy method (MEM). The author recorded vascular murmurs both before percutaneous transluminal angioplasty (PTA) and after. Examining the MEM spectral characteristics of the high-pitch stenosis murmurs, three features could be classified, which covered 85 percent of stenosis vascular murmurs. The features were learnt by the ANN, and judged. As a result, a percentage of judging the classified stenosis murmurs was 100%, and that of normal was 86%.

Computer simulation of magnetization-controlled shunt reactors for calculating electromagnetic transients in power systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karpov, A. S.

2013-01-15

A computer procedure for simulating magnetization-controlled dc shunt reactors is described, which enables the electromagnetic transients in electric power systems to be calculated. It is shown that, by taking technically simple measures in the control system, one can obtain high-speed reactors sufficient for many purposes, and dispense with the use of high-power devices for compensating higher harmonic components.

Magnetic Resonance Characterization of Cardiac Adaptation and Myocardial Fibrosis in Pulmonary Hypertension Secondary to Systemic-To-Pulmonary Shunt.

PubMed

Pereda, Daniel; García-Lunar, Inés; Sierra, Federico; Sánchez-Quintana, Damián; Santiago, Evelyn; Ballesteros, Constanza; Encalada, Juan F; Sánchez-González, Javier; Fuster, Valentín; Ibáñez, Borja; García-Álvarez, Ana

2016-09-01

Pulmonary hypertension (PH) and right ventricular (RV) dysfunction are strong predictors of morbidity and mortality among patients with congenital heart disease. Early detection of RV involvement may be useful in the management of these patients. We aimed to assess progressive cardiac adaptation and quantify myocardial extracellular volume in an experimental porcine model of PH because of aorto-pulmonary shunt using cardiac magnetic resonance (CMR). To characterize serial cardiac adaptation, 12 pigs (aorto-pulmonary shunt [n=6] or sham operation [n=6]) were evaluated monthly with right heart catheterization, CMR, and computed tomography during 4 months, followed by pathology analysis. Extracellular volume by CMR in different myocardial regions was studied in 20 animals (aorto-pulmonary shunt [n=10] or sham operation [n=10]) 3 months after the intervention. All shunted animals developed PH. CMR evidenced progressive RV hypertrophy and dysfunction secondary to increased afterload and left ventricular dilatation secondary to volume overload. Shunt flow by CMR strongly correlated with PH severity, left ventricular end-diastolic pressure, and left ventricular dilatation. T1-mapping sequences demonstrated increased extracellular volume at the RV insertion points, the interventricular septum, and the left ventricular lateral wall, reproducing the pattern of fibrosis found on pathology. Extracellular volume at the RV insertion points strongly correlated with pulmonary hemodynamics and RV dysfunction. Prolonged systemic-to-pulmonary shunting in growing piglets induces PH with biventricular remodeling and myocardial fibrosis that can be detected and monitored using CMR. These results may be useful for the diagnosis and management of congenital heart disease patients with pulmonary overcirculation. © 2016 American Heart Association, Inc.

Clinical features of congenital portosystemic shunt in children.

PubMed

Kim, Myung Jin; Ko, Jae Sung; Seo, Jeong Kee; Yang, Hye Ran; Chang, Ju Young; Kim, Gi Beom; Cheon, Jung-Eun; Kim, Woo Sun

2012-02-01

Clinical features, images, complications, treatments, and prognosis of 10 children with congenital portosystemic shunt (CPSS) were reviewed. Nine children were diagnosed with intrahepatic shunts while one presented with extrahepatic shunt. CPSS was detected by prenatal ultrasonography in four infants. Three infants presented with galactosemia without an enzyme deficiency. Two children presented with mental retardation and attention deficit hyperactivity disorder. Pulmonary hypertension developed in two patients. Spontaneous closure occurred in four infants with intrahepatic shunts including patent ductus venosus. The shunts were closed using transcatheter embolizations in four patients with intrahepatic shunts. Intrahepatic shunts may close spontaneously. Transcatheter embolization is effective for the treatment of symptomatic intrahepatic shunts.

Digital histology quantification of intra-hepatic fat in patients undergoing liver resection.

PubMed

Parkin, E; O'Reilly, D A; Plumb, A A; Manoharan, P; Rao, M; Coe, P; Frystyk, J; Ammori, B; de Liguori Carino, N; Deshpande, R; Sherlock, D J; Renehan, A G

2015-08-01

High intra-hepatic fat (IHF) content is associated with insulin resistance, visceral adiposity, and increased morbidity and mortality following liver resection. However, in clinical practice, IHF is assessed indirectly by pre-operative imaging [for example, chemical-shift magnetic resonance (CS-MR)]. We used the opportunity in patients undergoing liver resection to quantify IHF by digital histology (D-IHF) and relate this to CT-derived anthropometrics, insulin-related serum biomarkers, and IHF estimated by CS-MR. A reproducible method for quantification of D-IHF using 7 histology slides (inter- and intra-rater concordance: 0.97 and 0.98) was developed. In 35 patients undergoing resection for colorectal cancer metastases, we measured: CT-derived subcutaneous and visceral adipose tissue volumes, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), fasting serum adiponectin, leptin and fetuin-A. We estimated relative IHF using CS-MR and developed prediction models for IHF using a factor-clustered approach. The multivariate linear regression models showed that D-IHF was best predicted by HOMA-IR (Beta coefficient(per doubling): 2.410, 95% CI: 1.093, 5.313) and adiponectin (β(per doubling): 0.197, 95% CI: 0.058, 0.667), but not by anthropometrics. MR-derived IHF correlated with D-IHF (rho: 0.626; p = 0.0001), but levels of agreement deviated in upper range values (CS-MR over-estimated IHF: regression versus zero, p = 0.009); this could be adjusted for by a correction factor (CF: 0.7816). Our findings show IHF is associated with measures of insulin resistance, but not measures of visceral adiposity. CS-MR over-estimated IHF in the upper range. Larger studies are indicated to test whether a correction of imaging-derived IHF estimates is valid. Copyright © 2015 Elsevier Ltd. All rights reserved.

The role of liver transplantation for congenital extrahepatic portosystemic shunt.

PubMed

Sakamoto, Seisuke; Shigeta, Takanobu; Fukuda, Akinari; Tanaka, Hideaki; Nakazawa, Atsuko; Nosaka, Shunsuke; Uemoto, Shinji; Kasahara, Mureo

2012-06-27

Congenital extrahepatic portosystemic shunt (CEPS) is reported more frequently because of advances in imaging techniques. Liver transplantation (LT) is a therapeutic option, although the indications for LT are still controversial. This study reviewed 34 cases of LT for CEPS, including 30 cases reported in the English medical literature and the patients treated in our department, to collect the clinical data associated with LT. The median age at diagnosis and LT was 3.7 and 6.8 years, respectively. Hepatic encephalopathy, including persistent hyperammonemia, was the most common indication of LT. Pulmonary complications, including hepatopulmonary syndrome and pulmonary hypertension, were the second most common indications of LT, and those patients underwent LT soon after the diagnosis. Although a shunt directly draining into the inferior vena cava was the most common type and managed by a simple direct anastomosis of the portal vein at LT, some cases required the modification of the portal vein reconstruction, such as interposition. Thirty patients were alive with a median follow-up period of 18 months. LT for CEPS showed an excellent outcome. The development of pulmonary complications is an early indication for LT. Precise planning of portal vein reconstruction is required before LT.

Aqueous shunt implantation in glaucoma

PubMed Central

Wang, Jing; Barton, Keith

2017-01-01

Aqueous shunts or glaucoma drainage devices are increasingly utilized in the management of refractory glaucoma. The general design of the most commonly-used shunts is based on the principles of the Molteno implant: ie. a permanent sclerostomy (tube), a predetermined bleb area (plate) and diversion of aqueous humour to the equatorial region and away from the limbal subconjunctival space. These three factors make aqueous shunts more resistant to scarring as compared to trabeculectomy. The two most commonly used shunts are the Ahmed Glaucoma Valve, which contains a flow-restrictor, and the non-valved Baervedlt Glaucoma Implant. While the valved implants have a lower tendency to hypotony and related complications, the non-valved implants with larger, more-biocompatible end plate design, achieve lower intraocular pressures with less encapsulation. Non-valved implants require additional suturing techniques to prevent early hypotony and a number of these methods will be described. Although serious shunt-related infection is rare, corneal decompensation and diplopia are small but significant risks. PMID:29034151

Effect of bladder augmentation on VP shunt failure rates in spina bifida.

PubMed

Gonzalez, Dani O; Cooper, Jennifer N; McLeod, Daryl J

2017-12-11

Most patients with spina bifida require ventriculoperitoneal (VP) shunt placement. Some also require bladder augmentation, which may increase the risk of VP shunt malfunction and/or failure. The aim of this study was to assess whether bladder augmentation affects the rate of VP shunt failure in this population. Using the Pediatric Health Information System, we studied patients with spina bifida born between 1992 and 2014 who underwent VP shunt placement. Using conditional logistic regression, we compared age- and hospital-matched patients who did and did not undergo a bladder augmentation to determine their difference in rates of VP shunt failure. There were 4192 patients with spina bifida who underwent both surgical closure and VP shunt placement. Of these, 203 patients with bladder augmentation could be matched to 593 patients without bladder augmentation. VP shunt failure occurred within 2 years in 7.7% of patients, the majority of whom were in the group who underwent bladder augmentation (87%). After adjusting for confounders, undergoing bladder augmentation was independently associated with VP shunt failure (HR: 33.5, 95% CI: 13.15-85.44, p< 0.001). Bladder augmentation appears to be associated with VP shunt failure. Additional studies are necessary to better define this relationship and identify risk-reduction techniques.

Comparative durability and costs analysis of ventricular shunts.

PubMed

Agarwal, Nitin; Kashkoush, Ahmed; McDowell, Michael M; Lariviere, William R; Ismail, Naveed; Friedlander, Robert M

2018-05-11

OBJECTIVE Ventricular shunt (VS) durability has been well studied in the pediatric population and in patients with normal pressure hydrocephalus; however, further evaluation in a more heterogeneous adult population is needed. This study aims to evaluate the effect of diagnosis and valve type-fixed versus programmable-on shunt durability and cost for placement of shunts in adult patients. METHODS The authors retrospectively reviewed the medical records of all patients who underwent implantation of a VS for hydrocephalus at their institution over a 3-year period between August 2013 and October 2016 with a minimum postoperative follow-up of 6 months. The primary outcome was shunt revision, which was defined as reoperation for any indication after the initial procedure. Supply costs, shunt durability, and hydrocephalus etiologies were compared between fixed and programmable valves. RESULTS A total of 417 patients underwent shunt placement during the index time frame, consisting of 62 fixed shunts (15%) and 355 programmable shunts (85%). The mean follow-up was 30 ± 12 (SD) months. The shunt revision rate was 22% for programmable pressure valves and 21% for fixed pressure valves (HR 1.1 [95% CI 0.6-1.8]). Shunt complications, such as valve failure, infection, and overdrainage, occurred with similar frequency across valve types. Kaplan-Meier survival curve analysis showed no difference in durability between fixed (mean 39 months) and programmable (mean 40 months) shunts (p = 0.980, log-rank test). The median shunt supply cost per index case and accounting for subsequent revisions was $3438 (interquartile range $2938-$3876) and $1504 (interquartile range $753-$1584) for programmable and fixed shunts, respectively (p < 0.001, Wilcoxon rank-sum test). Of all hydrocephalus etiologies, pseudotumor cerebri (HR 1.9 [95% CI 1.2-3.1]) and previous shunt malfunction (HR 1.8 [95% CI 1.2-2.7]) were found to significantly increase the risk of shunt revision. Within each diagnosis

Clinical features and predictors of outcome in acute hepatitis A and hepatitis E virus hepatitis on cirrhosis.

PubMed

Radha Krishna, Yellapu; Saraswat, Vivek Anand; Das, Khaunish; Himanshu, Goel; Yachha, Surender Kumar; Aggarwal, Rakesh; Choudhuri, Gour

2009-03-01

Acute hepatitis A and E are recognized triggers of hepatic decompensation in patients with cirrhosis, particularly from the Indian subcontinent. However, the resulting acute-on-chronic liver failure (ACLF) has not been well characterized and no large studies are available. Our study aimed to evaluate the clinical profile and predictors of 3-month mortality in patients with this distinctive form of liver failure. ACLF was diagnosed in patients with acute hepatitis A or E [abrupt rise in serum bilirubin and/or alanine aminotransferase with positive immunoglobulin M anti-hepatitis A virus (HAV)/anti-hepatitis E virus (HEV)] presenting with clinical evidence of liver failure (significant ascites and/or hepatic encephalopathy) and clinical, biochemical, endoscopic (oesophageal varices at least grade II in size), ultrasonographical (presence of nodular irregular liver with porto-systemic collaterals) or histological evidence of cirrhosis. Clinical and laboratory profile were evaluated, predictors of 3-month mortality were determined using univariate and multivariate logistic regression and a prognostic model was constructed. Receiver-operating curves were plotted to measure performance of the present prognostic model, model for end-stage liver disease (MELD) score and Child-Turcotte-Pugh (CTP) score. ACLF occurred in 121 (3.75%) of 3220 patients (mean age 36.3+/-18.0 years; M:F 85:36) with liver cirrhosis admitted from January 2000 to June 2006. It was due to HEV in 80 (61.1%), HAV in 33 (27.2%) and both in 8 (6.1%). The underlying liver cirrhosis was due to HBV (37), alcohol (17), Wilson's disease (8), HCV (5), autoimmune (6), Budd-Chiari syndrome (2), haemochromatosis (2) and was cryptogenic in the rest (42). Common presentations were jaundice (100%), ascites (78%) and hepatic encephalopathy (55%). Mean (SD) CTP score was 11.4+/-1.6 and mean MELD score was 28.6+/-9.06. Three-month mortality was 54 (44.6%). Complications seen were sepsis in 42 (31.8%), renal failure in

Current treatment of normal-pressure hydrocephalus: comparison of flow-regulated and differential-pressure shunt valves.

PubMed

Weiner, H L; Constantini, S; Cohen, H; Wisoff, J H

1995-11-01

FROM THE RECORDS of approximately 1500 shunt operations performed between 1987 and 1992, we identified 37 adults between ages 38 and 86 years (mean, 70 yr) with the normal-pressure hydrocephalus (NPH) syndrome who underwent surgery by a single surgeon. Since 1990, we have routinely used a flow-regulated shunt system (Orbis-Sigma valve [OSV]; Cordis Corporation, Miami, FL) in these patients. In this study, we compared the OSV system with conventional differential-pressure (DP) shunt systems uniformly used before 1990. This series (n = 37) consisted of 62% men (n = 23) and 38% women (n = 14). We excluded all patients with hydrocephalus associated with central nervous system neoplasms, intracerebral hemorrhage, or trauma as well those with radiographically documented late-onset aqueductal stenosis. All patients presented with the NPH clinical syndrome, chiefly with magnetic gait. In addition, 75% of patients experienced cognitive loss and 59% experienced urinary incontinence. The mean duration of preoperative symptoms was 35 months (range, 7-120 mo). Eight patients (22%) had undergone previous shunting procedures before referral to our service. A total of 89 shunt operations were performed in the 37 patients. Using actuarial methods and controlling for a history of prior shunt surgery, we found no significant difference in the time to initial malfunction (shunt survival) between the OSV and the DP shunts. There were three subdural hematomas and one infection in the OSV group compared with no complications in the DP valve group (P = 0.11). Thirty-six patients were available for follow-up, at a mean of 14 months after surgery. Nearly 90% of all patients experienced improvement in gait after shunting, regardless of the valve system that was used. There was one unrelated death. Realizing the limitations of a retrospective analysis and on the basis of the limited number of patients in this study, we conclude that using actuarial methods, we found no significant difference

A complex scenario of tuberculosis transmission is revealed through genetic and epidemiological surveys in Porto.

PubMed

Rito, Teresa; Matos, Carlos; Carvalho, Carlos; Machado, Henrique; Rodrigues, Gabriela; Oliveira, Olena; Ferreira, Eduarda; Gonçalves, Jorge; Maio, Lurdes; Morais, Clara; Ramos, Helena; Guimarães, João Tiago; Santos, Catarina L; Duarte, Raquel; Correia-Neves, Margarida

2018-01-25

Tuberculosis (TB) incidence is decreasing worldwide and eradication is becoming plausible. In low-incidence countries, intervention on migrant populations is considered one of the most important strategies for elimination. However, such measures are inappropriate in European areas where TB is largely endemic, such as Porto in Portugal. We aim to understand transmission chains in Porto through a genetic characterization of Mycobacterium tuberculosis strains and through a detailed epidemiological evaluation of cases. We genotyped the M. tuberculosis strains using the MIRU-VNTR system. We performed an evolutionary reconstruction of the genotypes with median networks, used in this context for the first time. TB cases from a period of two years were evaluated combining genetic, epidemiological and georeferencing information. The data reveal a unique complex scenario in Porto where the autochthonous population acts as a genetic reservoir of M. tuberculosis diversity with discreet episodes of transmission, mostly undetected using classical epidemiology alone. Although control policies have been successful in decreasing incidence in Porto, the discerned complexity suggests that, for elimination to be a realistic goal, strategies need to be adjusted and coupled with a continuous genetic characterization of strains and detailed epidemiological evaluation, in order to successfully identify and interrupt transmission chains.

Superconducting fault current-limiter with variable shunt impedance

DOEpatents

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.

Evaluation of Blalock-Taussig shunts in newborns: value of oblique MRI planes.

PubMed

Kastler, B; Livolsi, A; Germain, P; Zöllner, G; Dietemann, J L

1991-01-01

Eight infants with systemic-pulmonary Blalock-Taussig shunts were evaluated by spin-echo ECG-gated MRI. Contrary to Echocardiography, MRI using coronal oblique projections successfully visualized all palliative shunts entirely in one single plane (including one carried out on a right aberrant subclavian artery). MRI allowed assessment of size, course and patency of the shunt, including pulmonary and subclavian insertion. The proximal portion of the pulmonary and subclavian arteries were also visualized. We conclude that MRI with axial scans completed by coronal oblique planes is a promising, non invasive method for imaging the anatomical features of Blalock-Taussig shunts.

Modified technique for preparation of venous circulation resin casts in the cirrhotic liver.

PubMed

Vasconcelos, José Olímpio Maia DE; Batista, Laécio Leitão; Pitta, Guilherme Benjamin Brandão; Lacerda, Cláudio Moura

2016-01-01

This study describes two major adaptations for the preparation of resin casts in human cirrhotic liver, harvested at the time of transplantation. The first is the way of fixing the catheter in the ostia of the hepatic and portal veins through a cerclage, so as to prevent displacement of the catheter and / or leakage of the resin during its injection. The second is the extension of corrosion time in the NaOH solution, averaging 6.8 days, with daily replacement the solution until complete removal of parenchymal tissue. We applied the method in 14 cirrhotic livers, with good filling and coloring of the portal and hepatic vein territories, using different colors. This allows an anatomical study of these vessels, able to complement the knowledge of the histopathology in research work, and the planning of therapeutic procedures, such as the Trans-Jugular Intrahepatic Port-Systemic Shunt (TIPS). RESUMO Este estudo descreve duas importantes adaptações para o preparo de moldes de resina em fígado humano cirrótico, captado no momento do transplante: a primeira, é a maneira de fixação dos cateteres nos "óstios" das veias hepáticas e porta, através de uma "cerclagem" dos mesmos, de modo a evitar o deslocamento do cateter e/ou extravasamento da resina durante sua injeção, e a segunda, é o prolongamento do tempo de corrosão na solução de NaOH, atingindo a média de 6,8 dias, com a substituição diária da solução, até a remoção completa do tecido parenquimatoso. O método foi empregado em 14 fígados cirróticos com bom preenchimento e coloração dos territórios das veias porta e hepáticas, utilizando cores distintas. Isto permite um estudo anatômico desses vasos, capaz de complementar os conhecimentos da histopatologia em trabalhos de pesquisa, e planejar procedimentos terapêuticos como a derivação porto-sistêmica intra-hepática transjugular (TIPS - Transjugular Intrahepatic Postosystemic Shunt).

Long-term evaluation of a new ventriculoperitoneal shunt valve system in a dog.

PubMed

Filgueiras, Richard da Rocha; Martins, Christine de Souza; de Almeida, Ricardo Miyasaka; Silva, Rosana Marques; da Rocha, Martha de Souza Teixeira; Firmino, Fernanda de Paula; Maguilnik, Samara; Medeiros, Luíza Quintão

2009-12-01

To report on the use of a new ventriculoperitoneal shunt (VPS) valve system utilized in a dog with hydrocephalus and to describe the clinical course over 20 months after implantation. A 3-month-old female Lhasa Apso dog was presented with lateral strabismus, domed calvarium, and visual deficits. A lateral skull radiograph revealed a persistent fontanelle. Transfontanellar ultrasonographic examination and computed tomographic examination showed excessive accumulation of fluid within the ventricles. The owner had observed symptoms as early as 1 month after birth, suggesting congenital hydrocephalus. A VPS with a new valve system that inhibits cerebrospinal fluid overdrainage and obstruction of the catheter was implanted. The dog showed clinical improvement 48 hours after the procedure. Twenty days after shunt implantation, another computed tomography scan was performed that showed reduction in ventricle size. The evaluation of VPS patency was carried out 20 months after surgery and demonstrated that the system was working properly without obstruction. There are reports in the literature describing the use of several devices to perform VPS in dogs. A new device not previously described in the veterinary literature was used in this case report, and according to the manufacturer's description, this device inhibits proteinaceous build-up, which is usually responsible for subsequent catheter obstructions.

Hepatic "BOLSA" a novel method of perihepatic wrapping for hepatic hemorrhage "BOLSA".

PubMed

Ng, Nathaniel; McLean, Susan F; Ghaleb, Melhem R; Tyroch, Alan H

2015-01-01

Severe traumatic liver hemorrhage quickly leads to exsanguination. Perihepatic packing is frequently used in damage control surgery. This method can be unsuccessful and accompanied by complications. Vicryl mesh wraps have been described in the treatment of liver hemorrhage. In this report, we describe an enhanced technique of hepatic wrapping in a case of hepatic bleeding after liver biopsy in a coagulopathic patient. The technique is called the hepatic "BOLSA" (Bag on Liver Supporting Anti-Hemorrhage). A 59 year old male presented in the recovery room after liver biopsy of a mass, followed by angio-embolization of the hepatic mass 9h earlier. The patient was acidotic, coagulopathic, and demonstrated intra-abdominal hypertension. Computed tomography demonstrated perihepatic fluid. The patient continued hemorrhaging despite attempts to correct coagulopathy by transfusion. Multiple operating room visits were required where a combination of packing and hemostatic agents could not stop hepatic venous parenchymal hemorrhage. Mesh wrap consisting of Vicryl and PDS suture were used to create the "BOLSA" to achieve hemostasis. Perihepatic packing compromises pulmonary excursion, elevates intra-abdominal pressure, is a risk factor for sepsis, and requires an additional trip to the operating room for removal. The use of Vicryl mesh wrap obviates these complications. Previously described mesh wraps require anchoring. The self-supporting structure of the BOLSA simplifies construction and application. The BOLSA is an effective tool in treatment of severe liver hemorrhage in coagulopathic patients. It is the modern simplification of hepatic wrapping and the solution to the side effects of perihepatic packing. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Angiostrongylus vasorum Causing Severe Granulomatous Hepatitis with Concurrent Multiple Acquired PSS.

PubMed

Cook, Simon; Priestnall, Simon L; Blake, Damer; Meeson, Richard L

2015-01-01

A 14 mo old female Jack Russell terrier presented with a 12 hr history of vomiting and inappetence. She was subsequently diagnosed with multiple acquired portosystemic shunts during an exploratory celiotomy. Gross and histopathological hepatic abnormalities were consistent with chronic disease, including features suggestive of portal hypertension that was potentially caused by migrating and resident Angiostrongylus vasorum larvae. Fecal analysis and polymerase chain reaction of hepatic tissue confirmed the presence of Angiostrongylus vasorum . The dog recovered clinically following empirical treatment and supportive care. A lack of parasite burden was confirmed 9 wk postdiagnosis; however, serum biochemical analysis at that time was suggestive of ongoing hepatic dysfunction.

The results of systems tests of the 500 kV busbar controllable shunting reactor in the Tavricheskaya substation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gusev, S. I.; Karpov, V. N.; Kiselev, A. N.

2009-09-15

The results of systems tests of the 500 kV busbar magnetization-controllable shunting reactor (CSR), set up in the Tavricheskaya substation, including measurements of the quality of the electric power, the harmonic composition of the network currents of the reactor for different values of the reactive power consumed, the determination of the regulating characteristics of the reactor, the speed of response of the shunting reactor in the current and voltage stabilization modes, and also the operation of the reactor under dynamic conditions for different perturbations, are presented. The results obtained are analyzed.

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

PubMed

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

2014-03-01

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

Do antibiotic-impregnated shunts in hydrocephalus therapy reduce the risk of infection? An observational study in 258 patients

PubMed Central

Ritz, Rainer; Roser, Florian; Morgalla, Matthias; Dietz, Klaus; Tatagiba, Marcos; Will, Bernd E

2007-01-01

Background Shunt infection in hydrocephalus patients is a severe, even life-threatening complication. Antibiotic-impregnated shunts (AIS) have been developed in an attempt to reduce rate of shunt infection. The study was performed to analyze if AIS can diminish the rate of shunt infection. The pathogenic nature of shunt infection in patients with AIS systems and those without antibiotic impregnated shunts (non-AIS) was compared. Methods Over a period of 24 months in the Department of Neurosurgery at University Hospital of Tübingen shunt surgery was performed in 258 patients. In 86 patients AIS systems were implanted. Shunt catheters were commercially impregnated with clindamycin and rifampicin. Analysis of the clinical data included sex, age, classification of hydrocephalus, shunt types and risk factors for shunt infection [age (< 1 year and > 80 years), prematurely born patients, external ventricular drainage, former shunt infection, former systemic infection, disturbance of consciousness, former radiation-/chemotherapy]. Infection rates and underlying bacterial pathogens of patients with AIS were compared to patients with implanted non-AIS systems (172 patients). Results AIS and non-AIS patients did not differ in sex, etiology of hydrocephalus and the shunt type. In the AIS group 72 out of 86 patients had at least one risk factor (83.7 %), compared to 126 patients in the non-AIS group (73.3 %). There was no significant difference between the two groups (p = 0.0629; Fisher's exact test). In patients with no risk factors, only one patient with non-AIS suffered from shunt infection. In patients with one or more risk factors the rate for shunt infection was 7.14 % in patients with non-AIS and 6.94 % in patients with AIS. Former shunt infection (p = 0.0124) was related to higher risk for shunt infection. The use of AIS had therefore no significant advantage (p = 0.8611; multiple logistic regression). Significantly related to a shunt infection was the number of shunt

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

PubMed

Gong, Ying; Zhu, Hui; Chen, Jun; Chen, Qi; Ji, Min; Pa, Mier; Zheng, Shan; Qiao, Zhongwei

2015-12-01

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.

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2012 CFR

2012-04-01

... System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2855 Implantable Intra-aneurysm Pressure Measurement System. (a) Identification. Implantable intra...

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2013 CFR

2013-04-01

... System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2855 Implantable Intra-aneurysm Pressure Measurement System. (a) Identification. Implantable intra...

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2014 CFR

2014-04-01

... System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2855 Implantable Intra-aneurysm Pressure Measurement System. (a) Identification. Implantable intra...

21 CFR 870.3535 - Intra-aortic balloon and control system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... syndrome, cardiac and non-cardiac surgery, or complications of heart failure. The special controls for this... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intra-aortic balloon and control system. 870.3535... balloon and control system. (a) Identification. An intra-aortic balloon and control system is a...

Multi-resonant electromagnetic shunt in base isolation for vibration damping and energy harvesting

NASA Astrophysics Data System (ADS)

Pei, Yalu; Liu, Yilun; Zuo, Lei

2018-06-01

This paper investigates multi-resonant electromagnetic shunts applied to base isolation for dual-function vibration damping and energy harvesting. Two multi-mode shunt circuit configurations, namely parallel and series, are proposed and optimized based on the H2 criteria. The root-mean-square (RMS) value of the relative displacement between the base and the primary structure is minimized. Practically, this will improve the safety of base-isolated buildings subjected the broad bandwidth ground acceleration. Case studies of a base-isolated building are conducted in both the frequency and time domains to investigate the effectiveness of multi-resonant electromagnetic shunts under recorded earthquake signals. It shows that both multi-mode shunt circuits outperform traditional single mode shunt circuits by suppressing the first and the second vibration modes simultaneously. Moreover, for the same stiffness ratio, the parallel shunt circuit is more effective at harvesting energy and suppressing vibration, and can more robustly handle parameter mistuning than the series shunt circuit. Furthermore, this paper discusses experimental validation of the effectiveness of multi-resonant electromagnetic shunts for vibration damping and energy harvesting on a scaled-down base isolation system.

A case report of progressive obstruction of Ex-PRESS miniature glaucoma shunt after transient flat anterior chamber and treatment using Nd:YAG laser.

PubMed

Tanito, Masaki; Sano, Ichiya; Ohira, Akihiro

2015-01-08

We report a case of Ex-PRESS miniature glaucoma shunt obstruction resulting from progressive iris synechial formation after transient anterior chamber shallowing. A 68-year-old woman with pseudoexfoliation glaucoma in her right eye underwent filtration surgery with implantation of the Ex-PPESS shunt (model P-50, Alcon Japan, Tokyo, Japan) in combination with intra-surgical 0.04% mitomycin C use. After the anterior chamber injection of viscoelastic material and 100% sulfur hexafluoride gas for treatment of early postoperative over filtration, the intraocular pressure (IOP) was controlled between 9 and 12 mmHg. On postoperative day 121, gonioscopy showed that synechial formation around the shunt obstructed the axial port leaving the relief port opened. On postoperative day 274, the intraocular pressure increased to 40 mmHg and synechiae obstructed both the axial and relief ports. Dispersion of iris tissue by neodymium:yttrium-aluminium-garnet (Nd:YAG) laser (2 mJ, one shot to each port) opened both ports and immediately lowered the IOP, leaving peripheral anterior synechiae around the shunt. Up to postoperative day 400, the IOP was controlled between 13 and 15 mmHg, and the cystic bleb was maintained. The synechiae formed gradually extends around the shunt's shaft and can result in later external obstruction of the relief port. The current case requires further follow-up since synechiae remaining around the shaft can cause future obstruction. We emphasize the fact that, if the iris synechiae to the shunt once formed, it can progress and obstruct the shunt ports later.

Congenital extrahepatic portosystemic shunt (Abernethy malformation) treated endovascularly with vascular plug shunt closure.

PubMed

Passalacqua, Matthew; Lie, Kevin T; Yarmohammadi, Hooman

2012-01-01

A 3-year-old boy, who presented with progressive cyanosis and hypoxia, was diagnosed with a large congenital extrahepatic portosystemic shunt, interrupted IVC with azygos continuation, and multiple congenital anomalies. Traditionally open and laparoscopic surgical techniques have been used to treat this malformation. Endovascular repair using a 16-mm Amplatzer vascular plug (AGA Medical Corporation, Golden Valley, Minnesota, USA) was used to occlude the shunt. Immediate post-placement venography demonstrated cessation of flow within the shunt and increased portal venous flow. The patient's hypoxia and cyanosis decreased significantly, and he was discharged on the 5th post-procedure day in stable clinical condition. Three months follow-up evaluation demonstrated the vascular plug in place, unchanged in position.

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

Use of C-Arm Cone Beam CT During Hepatic Radioembolization: Protocol Optimization for Extrahepatic Shunting and Parenchymal Enhancement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoven, Andor F. van den, E-mail: a.f.vandenhoven@umcutrecht.nl; Prince, Jip F.; Keizer, Bart de

PurposeTo optimize a C-arm computed tomography (CT) protocol for radioembolization (RE), specifically for extrahepatic shunting and parenchymal enhancement.Materials and MethodsA prospective development study was performed per IDEAL recommendations. A literature-based protocol was applied in patients with unresectable and chemorefractory liver malignancies undergoing an angiography before radioembolization. Contrast and scan settings were adjusted stepwise and repeatedly reviewed in a consensus meeting. Afterwards, two independent raters analyzed all scans. A third rater evaluated the SPECT/CT scans as a reference standard for extrahepatic shunting and lack of target segment perfusion.ResultsFifty scans were obtained in 29 procedures. The first protocol, using a 6 s delaymore » and 10 s scan, showed insufficient parenchymal enhancement. In the second protocol, the delay was determined by timing parenchymal enhancement on DSA power injection (median 8 s, range 4–10 s): enhancement improved, but breathing artifacts increased (from 0 to 27 %). Since the third protocol with a 5 s scan decremented subjective image quality, the second protocol was deemed optimal. Median CNR (range) was 1.7 (0.6–3.2), 2.2 (−1.4–4.0), and 2.1 (−0.3–3.0) for protocol 1, 2, and 3 (p = 0.80). Delineation of perfused segments was possible in 57, 73, and 44 % of scans (p = 0.13). In all C-arm CTs combined, the negative predictive value was 95 % for extrahepatic shunting and 83 % for lack of target segment perfusion.ConclusionAn optimized C-arm CT protocol was developed that can be used to detect extrahepatic shunts and non-perfusion of target segments during RE.« less

What is the risk of infecting a cerebrospinal fluid-diverting shunt with percutaneous tapping?

PubMed

Spiegelman, Lindsey; Asija, Richa; Da Silva, Stephanie L; Krieger, Mark D; McComb, J Gordon

2014-10-01

Most CSF-diverting shunt systems have an access port that can be percutaneously tapped. Tapping the shunt can yield valuable information as to its function and whether an infection is present. The fear of causing a shunt infection by tapping may limit the physician's willingness to do so. The authors of this study investigate the risk of infecting a shunt secondary to percutaneous tapping. Following institutional review board approval, CSF specimens obtained from tapping an indwelling CSF-diverting shunt during the 2011 and 2012 calendar years were identified and matched with clinical information. A culture-positive CSF sample was defined as an infection. If results were equivocal, such as a broth-only-positive culture, a repeat CSF specimen was examined. The CSF was obtained by tapping the shunt access port with a 25-gauge butterfly needle after prepping the unshaven skin with chlorhexidine. During the study period, 266 children underwent 542 shunt taps. With 541 taps, no clinical evidence of a subsequent shunt infection was found. One child's CSF went from sterile to infected 11 days later; however, this patient had redness along the shunt tract at the time of the initial sterile tap. The risk of infection from tapping a shunt is remote if the procedure is done correctly.

Management of Hepatic Encephalopathy Not Responsive to First-Line Treatments.

PubMed

Nardelli, Silvia; Ridola, Lorenzo; Gioia, Stefania; Riggio, Oliviero

2018-06-01

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome that occurs in up to 30% of patients with cirrhosis. HE may be a consequence of pure liver failure, as in patients with fulminant hepatitis, or of the combination of liver failure and portal-systemic shunting, as in patients with liver cirrhosis. Episodes of HE are usually related to precipitating events, such as infections or gastrointestinal bleeding; a minority of cirrhotic patients experienced a chronic HE, refractory to standard medical treatment. The prevention of HE recurrence, after the first episode of HE, could be obtained by the administration of prophylactic therapy with lactulose, rifaximin or a combination of both. The aim of this review is to clarify some key points in the management of cirrhotic patients with HE, not responsive to first line treatment. Recent studies investigated the role of fecal microbiota transplantation in the treatment of HE with promising results, but further investigations are needed. In a cirrhotic patient with acute cognitive impairment, the correct diagnosis of HE, after excluding other causes of neurological diseases, is mandatory for the correct management of the precipitating factors and for the treatment. In patients not responsive to standard treatment, the probable precipitating factors have not been correctly identified, multiple precipitating events are coexisting or a new precipitating event is superimposed. In some patients with recurrent HE, characterized by persistent alterations in neurological symptoms, without specific precipitants events, the presence of spontaneous or iatrogenic shunts should be investigated.

Implementation of Hepatitis Information Management System in Iran.

PubMed

Reza, Safdari; Jebraeil, Farzi; Akbar, Nasiri Ali; Marjan, Ghazisaeedi; Reza, Taghavi Mohammad; Mehdi, Afshari; Mahlagha, Sargolzaee; Farhad, Taji

2015-11-17

Nowadays, hepatitis is of the most important health priorities around the world, where information plays a very significant role in specialized diseases prevention planning, and policy- and decision-making processes. Thus, this study addressed challenges of hepatitis information management and investigated the outcomes of establishing a hepatitis information management system to overcome such challenges. To this end, this research intended to study the implementation of an Electronic hepatitis information management system. This is an applied-developmental study with following specifications and procedures: preparation of study proposal and design, justification of the design's stakeholders, approval of the design by the Postgraduate Education Council of Faculty, determination of pilot hepatitis control center, software development, deciding on control, prevention, and treatment centers, and finally development of a network-based system for collecting and managing hepatitis information. Results indicated that the inconsistency and lack of integrity of data, as well as the lack of communication between related units prevented timely information register of viral hepatic patients and services that are provided to them. This inhibited the possibility of considering a follow-up process. However, the implementation of this system and involvement of relevant units greatly solved these problems. Results show that the implementation of an electronic system for the management of hepatitis control, prevention, and treatment is a regional and national requirement; since, this system with its empowered infrastructure is capable in providing desired services to all laboratories, counseling and health centers, specialized clinics, and physicians connected to the hepatitis network. This enables them to follow up and monitor patients' conditions. That mentioned system paves the way for the analysis of gathered information, managers' and specialists' access in different regions to

Implementation of Hepatitis Information Management System in Iran

PubMed Central

Reza, Safdari; Jebraeil, Farzi; Akbar, Nasiri Ali; Marjan, Ghazisaeedi; Reza, Taghavi Mohammad; Mehdi, Afshari; Mahlagha, Sargolzaee; Farhad, Taji

2016-01-01

Introduction: Nowadays, hepatitis is of the most important health priorities around the world, where information plays a very significant role in specialized diseases prevention planning, and policy- and decision-making processes. Thus, this study addressed challenges of hepatitis information management and investigated the outcomes of establishing a hepatitis information management system to overcome such challenges. To this end, this research intended to study the implementation of an Electronic hepatitis information management system. Methodology: This is an applied-developmental study with following specifications and procedures: preparation of study proposal and design, justification of the design’s stakeholders, approval of the design by the Postgraduate Education Council of Faculty, determination of pilot hepatitis control center, software development, deciding on control, prevention, and treatment centers, and finally development of a network-based system for collecting and managing hepatitis information. Findings: Results indicated that the inconsistency and lack of integrity of data, as well as the lack of communication between related units prevented timely information register of viral hepatic patients and services that are provided to them. This inhibited the possibility of considering a follow-up process. However, the implementation of this system and involvement of relevant units greatly solved these problems. Conclusion: Results show that the implementation of an electronic system for the management of hepatitis control, prevention, and treatment is a regional and national requirement; since, this system with its empowered infrastructure is capable in providing desired services to all laboratories, counseling and health centers, specialized clinics, and physicians connected to the hepatitis network. This enables them to follow up and monitor patients’ conditions. That mentioned system paves the way for the analysis of gathered information

Ventriculosubgaleal shunts for posthemorrhagic hydrocephalus in premature infants.

PubMed

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

2005-01-01

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

3T magnetic resonance imaging testing of externally programmable shunt valves

PubMed Central

Zabramski, Joseph M.; Preul, Mark C.; Debbins, Josef; McCusker, Daniel J.

2012-01-01

Background: Exposure of externally programmable shunt-valves (EPS-valves) to magnetic resonance imaging (MRI) may lead to unexpected changes in shunt settings, or affect the ability to reprogram the valve. We undertook this study to examine the effect of exposure to a 3T MRI on a group of widely used EPS-valves. Methods: Evaluations were performed on first generation EPS-valves (those without a locking mechanism to prevent changes in shunt settings by external magnets other than the programmer) and second generation EPS-valves (those with a locking mechanisms). Fifteen new shunt-valves were divided into five groups of three identical valves each, and then exposed to a series of six simulated MRI scans. After each of the exposures, the valves were evaluated to determine if the valve settings had changed, and whether the valves could be reprogrammed. The study produced 18 evaluations for each line of shunt-valves. Results: Exposure of the first generation EPS-valves to a 3T magnetic field resulted in frequent changes in the valve settings; however, all valves retained their ability to be reprogrammed. Repeated exposure of the second generation EPS-valves has no effect on shunt valve settings, and all valves retained their ability to be interrogated and reprogrammed. Conclusions: Second generation EPS-valves with locking mechanisms can be safely exposed to repeated 3T MRI systems, without evidence that shunt settings will change. The exposure of the first generation EPS-valves to 3T MRI results in frequent changes in shunt settings that necessitate re-evaluation soon after MRI to avoid complications. PMID:22937481

[Ultrasound diagnosis of congenital intrahepatic portosystemic shunt].

PubMed

Fu, Qiang; Tan, Shi; Cui, Li-gang; Zhang, Hua-bin; Bai, Zhi-yong; Jiang, Jie

2013-12-01

To investigate the ultrasonographic features of congenital intrahepatic portosystemic venous shunt (CIPSVS) and to assess the clinical value of ultrasonography in the diagnosis of CIPSVS. Six cases of CIPSVS diagnosed in our hospital between March 2010 and March 2012 and confirmed by enhanced computed tomography (CT) were retrospectively reviewed. Five of the six cases had follow-up data that was included in the analysis. Among the six CIPSVS cases, only one was classified as Park's type II and the rest were classified as Park's type III. Five cases involved the right lobe of the liver and only one case involved the left lobe. The lesion shapes included cystic, tubular, and irregular with clear contour and appeared to be anechoic on CT scan. The lesions ranged in size from 1.1*0.6 cm to 2.0*1.7 cm. For all cases, the color Doppler ultrasound images showed blood flowing from the portal vein to the hepatic vein, and single-phase spectrum was detected in the diversion channel. The differences observed in level of lesion size and blood flow velocity at the shunt from the time of examinations at diagnosis and subsequent follow-up did not reach statistical significance (P = 0.223 more than 0.05 and P = 0.930 more than 0.05 respectively). Although cases of CIPSVS are rare, they share some specific sonographic features that may help in diagnosis. Color Doppler ultrasound findings have high diagnostic accuracy and may represent a preferred modality for follow-up monitoring.

Developing the 1st MOOC of University of Porto: Challenges and Strategies

ERIC Educational Resources Information Center

Martins, Isabel; Regadas, Nuno; Amaral, Margarida

2016-01-01

This article is a case study on how the educational technologies unit of the Digital University describes the experience of thinking, creating multimedia contents and training teachers regarding the development of the first MOOC of University of Porto (U.Porto). Upon describing this experience, we focus on the most relevant topics such as how the…

Prediction of Susceptibility to Acute Mountain Sickness Using Hypoxia-Induced Intrapulmonary Arteriovenous Shunt and Intracardiac Shunt Fractions

DTIC Science & Technology

2013-10-01

echocardiography to determine bubble/shunt scores. We will also use nuclear medicine imaging to determine shunt fractions following acute exposures to... echocardiography while breathing hypoxic gas mixtures. – TASK COMPLETED. For Task #1.3 “Quantify shunt during hypoxic exposure with SPECT CT – PFO...subjects.” 19 PFO+ subjects have completed saline contrast echocardiography while breathing hypoxic gas mixtures for 30 min. One PFO+ subject that had

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

PubMed

White, R N; Parry, A T

2016-05-01

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

Genomic Diversity of Hepatitis B Virus Infection Associated With Fulminant Hepatitis B Development.

PubMed

Mina, Thomas; Amini Bavil Olyaee, Samad; Tacke, Frank; Maes, Piet; Van Ranst, Marc; Pourkarim, Mahmoud Reza

2015-06-01

After five decades of Hepatitis B Virus (HBV) vaccine discovery, HBV is still a major public health problem. Due to the high genetic diversity of HBV and selective pressure of the host immune system, intra-host evolution of this virus in different clinical manifestations is a hot topic of research. HBV infection causes a range of clinical manifestations from acute to chronic infection, cirrhosis and hepatocellular carcinoma. Among all forms of HBV infection manifestations, fulminant hepatitis B infection possesses the highest fatality rate. Almost 1% of the acutely infected patients develop fulminant hepatitis B, in which the mortality rate is around 70%. All published papers deposited in Genbank, on the topic of fulminant hepatitis were reviewed and their virological aspects were investigated. In this review, we highlight the genomic diversity of HBV reported from patients with fulminant HBV infection. The most commonly detected diversities affect regulatory motifs of HBV in the core and S region, indicating that these alterations may convert the virus to an aggressive strain. Moreover, mutations at T-cell and B-cell epitopes located in pre-S1 and pre-S2 proteins may lead to an immune evasion of the virus, likely favoring a more severe clinical course of infection. Furthermore, point and frame shift mutations in the core region increase the viral replication of HBV and help virus to evade from immune system and guarantee its persistence. Fulminant hepatitis B is associated with distinct mutational patterns of HBV, underlining that genomic diversity of the virus is an important factor determining its pathogenicity.

Persistent hydrocephalus due to postural activation of a ventricular shunt anti-gravity device.

PubMed

Craven, Claudia L; Toma, Ahmed K; Watkins, Laurence D

2017-03-01

The ever present need to balance over drainage with under drainage in hydrocephalus has required innovations including adjustable valves with antigravity devices. These are activated in the vertical position to prevent siphoning. We describe a group of bedridden patients who presented with unexplained under drainage caused by activation of antigravity shunt components produced by peculiar head/body position. Retrospective single centre case series of hydrocephalus patients, treated with ventriculo-peritoneal (VP) shunt insertion between April 2014 - February 2016. These patients presented with clinical and radiological under drainage syndrome. Medical notes were reviewed for clinical picture and outcome. Radiological studies were reviewed assessing shunt placement and ventricular size. Seven patients presented with clinical and radiological under drainage syndrome. A consistent posturing of long term hyper-flexion of the neck whilst lying supine was observed. All patients had similar shunt construct (adjustable Miethke ProGAV valve and shunt assistant anti-gravity component). In each of those patients a hypothesis was formulated that neck flexion was activating the shunt assistance anti-gravity component in supine position. Five patients underwent shunt revision surgery removing the shunt assistant device from the cranium and adding an anti-gravity component to the shunt system at the chest. One had the shunt assistant completely removed and one patient was managed conservatively with mobilisation. All patients had clinical and radiological improvement. Antigravity shunt components implanted cranially in bedridden hydrocephalus patients will produce underdrainage due to head flexion induced anti-gravity device activation. In these patients, anti-gravity devices should be placed at the chest. Alternatively, special nursing attention should be paid to head-trunk angle. Copyright © 2016 Elsevier Ltd. All rights reserved.

The internal mammary artery as a shunt in a noncyanotic infant with hemitruncus: surgical and anesthetic management.

PubMed

Mahan, Vicki L; Stevens, Randy M; Mesia, Cesar I; Schwartz, Roy E; Moulick, Achintya N

2016-08-01

The internal mammary artery (IMA) has been used as a systemic-to-pulmonary artery shunt in selected patients with congenital heart disease. Growth and development of hypoplastic pulmonary arteries have been described. We discuss the surgical and anesthetic management of an infant with an atretic-thrombosed right pulmonary artery originating from the ascending aorta in whom the IMA was used to create a systemic-to-pulmonary artery shunt after failure of a previous shunt and later successful pulmonary artery reconstruction. The IMA should be considered as an alternative conduit in patients requiring a systemic-to-pulmonary artery shunt for growth of pulmonary arteries. Copyright © 2016 Elsevier Inc. All rights reserved.

Accounting for intra-molecular vibrational modes in open quantum system description of molecular systems.

PubMed

Roden, Jan; Strunz, Walter T; Whaley, K Birgitta; Eisfeld, Alexander

2012-11-28

Electronic-vibrational dynamics in molecular systems that interact with an environment involve a large number of degrees of freedom and are therefore often described by means of open quantum system approaches. A popular approach is to include only the electronic degrees of freedom into the system part and to couple these to a non-Markovian bath of harmonic vibrational modes that is characterized by a spectral density. Since this bath represents both intra-molecular and external vibrations, it is important to understand how to construct a spectral density that accounts for intra-molecular vibrational modes that couple further to other modes. Here, we address this problem by explicitly incorporating an intra-molecular vibrational mode together with the electronic degrees of freedom into the system part and using the Fano theory for a resonance coupled to a continuum to derive an "effective" bath spectral density, which describes the contribution of intra-molecular modes. We compare this effective model for the intra-molecular mode with the method of pseudomodes, a widely used approach in simulation of non-Markovian dynamics. We clarify the difference between these two approaches and demonstrate that the respective resulting dynamics and optical spectra can be very different.

An Auscultaiting Diagnosis Support System for Assessing Hemodialysis Shunt Stenosis by Using Self-organizing Map

NASA Astrophysics Data System (ADS)

Suzuki, Yutaka; Fukasawa, Mizuya; Sakata, Osamu; Kato, Hatsuhiro; Hattori, Asobu; Kato, Takaya

Vascular access for hemodialysis is a lifeline for over 280,000 chronic renal failure patients in Japan. Early detection of stenosis may facilitate long-term use of hemodialysis shunts. Stethoscope auscultation of vascular murmurs has some utility in the assessment of access patency; however, the sensitivity of this diagnostic approach is skill dependent. This study proposes a novel diagnosis support system to detect stenosis by using vascular murmurs. The system is based on a self-organizing map (SOM) and short-time maximum entropy method (STMEM) for data analysis. SOM is an artificial neural network, which is trained using unsupervised learning to produce a feature map that is useful for visualizing the analogous relationship between input data. The author recorded vascular murmurs before and after percutaneous transluminal angioplasty (PTA). The SOM-based classification was consistent with to the classification based on MEM spectral and spectrogram characteristics. The ratio of pre-PTA murmurs in the stenosis category was much higher than the post-PTA murmurs. The results suggest that the proposed method may be an effective tool in the determination of shunt stenosis.

[Congenital absence of the portal vein (CAPV). Two cases of Abernethy malformation type 1 and review of the literature].

PubMed

Ringe, K; Schirg, E; Melter, M; Flemming, P; Ringe, B; Becker, T; Galanski, M

2008-05-01

The Abernethy malformation is a rare congenital portosystemic shunt in which the blood directly drains into the systemic vein bypassing the liver either through a complete (type 1) or a partial shunt (type 2). The diagnosis is most frequently established primarily with ultrasound. CT and MRI are used for further classification of the shunt and assessment of accompanying liver tumors and malformations. There is a wide spectrum of therapeutic options ranging from noninvasive conservative treatment to liver transplantation. The main prognostic factors are the occurrence of concomitant hepatic neoplasms and hepatic encephalopathy. We report two cases diagnosed with a type 1 shunt, hepatic encephalopathy, and associated liver tumors who underwent successful liver transplantation after having considered all therapeutic options.

Experimental Percutaneous Extrahepatic Portacaval Shunt Creation by Transjugular Approach in Swine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seong, Chang Kyu; Pavcnik, Dusan, E-mail: pavcnikd@ohsu.edu; Uchida, Barry T.

2005-06-15

The purpose of the study was to evaluate the feasibility of the creation of a percutaneous extrahepatic portacaval shunt (PEPS) in swine by a transjugular approach and to find a suitable stent-graft to use in PEPS. In 12 swine, the extrahepatic portal vein (PV) was entered from the inferior vena cava (IVC) by a needle system introduced from the transjugular approach. A catheter introduced through the transhepatic approach served as a target. Five types of stent-graft consisting of homemade Z stents and a polytetrafluoethylene cover were explored for PEPS creation. Eight animals had follow-up venograms up to 6 weeks ormore » until the shunt became severely stenotic. Gross and histologic examinations were performed after the final follow-up venography. The PV punctures and stent-graft placement were difficult, but the PEPS was established in all animals. In four animals, the stent-graft failed to adequately cover the tract, causing severe hemorrhage. Only two shunts remained patent up to 6 weeks. The other shunts exhibited severe stenosis or occlusion. At gross examination, all shunts traversed the liver parenchyma of the caudate lobe surrounding the IVC. The extravascular PEPS portion was 4 mm to 2 cm long. All shunts entered the PV close to the splenomesenteric junction and exhibited neointimal formation. Shunt stenoses were caused by neointimal hyperplasia and occlusions by a superimposed thrombus. PEPS can be created by the transjugular approach in swine, but only the PV shunt entrance is extrahepatic. None of the tested rigid stent-grafts were suitable for PEPS creation. A short flexible stent-graft with flanged ends is suggested for further exploration.« less

Effect of Increased Intra-abdominal Pressure on Liver Histology and Hemodynamics: An Experimental Study

PubMed Central

ANTONIOU, EFSTATHIOS A; KAIRI, EVI; MARGONIS, GEORGIOS A; ANDREATOS, NIKOLAOS; SASAKI, KAZUNARI; DAMASKOS, CHRISTOS; GARMPIS, NIKOLAOS; SAMAHA, MARIO; ARGYRA, ERIPHYLI; POLYMENEAS, GEORGE; WEISS, MATTHEW J; PAWLIK, TIMOTHY M; VOROS, DIONYSIOS; KOURAKLIS, GREGORY

2018-01-01

Background: While reduction of portal venous (PV) blood flow has been described in animal models of intra-abdominal hypertension, reports on compensatory changes in hepatic arterial (HA) flow, known as the hepatic arterial buffer response are controversial. Materials and Methods: Pneumoperitoneum with helium was induced in 13 piglets. Hemodynamic measurements and pathological assessment were conducted at baseline and during the three subsequent phases: Phase A: 45 minutes with a stable intra-abdominal pressure of 25 mmHg; phase B: 45 minutes with a stable intra-abdominal pressure of 40 mmHg; and phase C during which the abdomen was re-explored and reperfusion of the liver was allowed to take place. Results: Phase B pressure was significantly greater than phase A pressure in both the PV and the inferior vena cava, demonstrating a positive association between escalating intra-abdominal hypertension and the pressure in these two vessels (all p<0.001). In contrast, HA pressure was comparable between baseline and phase A, while it tended to decrease in phase B. Regarding histology, the most notable abnormality was the presence of inflammatory infiltrates and hepatocyte necrosis. Conclusion: Helium-insufflation increased PV pressure with a partial compensatory decrease of HA pressure. Nonetheless, findings consistent with hepatic ischemia were observed on pathology. PMID:29275303

Outcome of infants shunted for post-haemorrhagic ventricular dilatation.

PubMed

Hislop, J E; Dubowitz, L M; Kaiser, A M; Singh, M P; Whitelaw, A G

1988-08-01

Between April 1980 and March 1986, 19 infants underwent cerebrospinal fluid (CSF) shunting procedures for post-haemorrhagic ventricular dilatation at the Hammersmith Hospital, London. A total of 58 shunt-related procedures have been performed on these children. The major perioperative complication was seizure activity (eight children). Postoperative complications included infection (12 shunts) and blockage (29 shunts). Prophylactic antibiotics failed to prevent shunt infection. The likelihood of the first shunt failing was significantly reduced by greater weight of the infant and lower CSF protein at surgery. Long-term outcome was poor: three have died and another four are quadriplegic with severe mental retardation. Only four children are developmentally normal. These outcomes cannot be related to the shunt surgery or its complications, but correlate best with pre-operative parenchymal brain-lesions, as shown on ultrasound scans.

Lower incidence of reoperation with longer shunt survival with adult ventriculoperitoneal shunts placed for hemorrhage-related hydrocephalus.

PubMed

Hoh, Brian L; Lang, Shih-Shan; Ortiz, Michael V; Chi, Yueh-Yun; Lewis, Stephen B; Pincus, David W

2008-07-01

The incidence of reoperation for ventriculoperitoneal shunts (VPS) in adults, although lower than in pediatric patients, is not insignificant. We hypothesize that adult VPS placed for hemorrhage-related hydrocephalus have a lower incidence of reoperation than those placed for other types of hydrocephalus. We retrospectively reviewed all adult (>/= 20 yr) VPS initially placed from February 2001 to August 2006 at the University of Florida. We determined the incidence and time interval to reoperation. Follow-up was conducted by telephone interview and review of medical records. A total of 286 adult VPS were initially placed: 96 (34%) hemorrhage and 190 (66%) nonhemorrhage. A total of 15 (16%) hemorrhage patients underwent 22 shunt reoperations, compared with 50 (27%) nonhemorrhage patients who underwent 82 shunt reoperations (P = 0.0316). A Poisson regression analysis of the number of reoperations, factoring hemorrhage, age, and sex, demonstrated a significantly lower incidence of reoperation in hemorrhage patients (P = 0.0900). A Cox proportional hazards model analysis of time to first reoperation, factoring hemorrhage, age, and sex, demonstrated a significantly longer shunt survival in hemorrhage patients (P = 0.0404). Adult VPS placed for hemorrhage-related hydrocephalus have a significantly lower incidence of reoperation and significantly longer shunt survival. This result may be related to an incidence of transient shunt dependency in patients with hemorrhage-related hydrocephalus. However, the precise mechanism remains unclear.

Resolution of Large Azygos Vein Aneurysm Following Stent-Graft Shunt Placement in a Patient with Ehlers-Danlos Syndrome Type IV

DOE Office of Scientific and Technical Information (OSTI.GOV)

D'Souza, Estelle S.; Williams, David M.; Deeb, G.M.

2006-10-15

Ehlers-Danlos syndrome (EDS) type IV is a rare connective tissue disorder associated with thin-walled, friable arteries and veins predisposing patients to aneurysm formation, dissection, fistula formation, and vessel rupture. Azygos vein aneurysm is an extremely rare condition which has not been reported in association with EDS in the literature. We present a patient with EDS type IV and interrupted inferior vena cava (IVC) with azygos continuation who developed an azygos vein aneurysm. In order to decrease flow through the azygos vein and reduce the risk of aneurysm rupture, a stent-graft shunt was created from the right hepatic vein to themore » azygos vein via a transhepatic, retroperitoneal route. At 6 month follow-up the shunt was open and the azygos vein aneurysm had resolved.« less

Radiocolloid liver imaging in tuberculous hepatitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Essop, A.R.; Posen, J.A.; Savitch, I.

1984-02-01

Twenty of 22 patients with tuberculous hepatitis had abnormal Tc-99m tin colloid liver scans. However, in the majority of the patients the changes were mild and nonspecific. The most frequent scintigraphic picture was a decreased uptake of the radiocolloid by the liver, with shunting to the spleen and bone marrow. The decreased hepatic uptake was usually mildly heterogeneous, but it was sometimes homogeneous, and in five patients obvious defects were present. The liver was enlarged in six patients and the spleen in six patients. Increased extrahepatic uptake of the radiocolloid was the only abnormality in five patients. The severity ofmore » the scintigraphic changes did not correlate with the following histologic findings: number of granulomas, degree of associated fibrosis, degree of hepatocyte swelling, or extent of fatty change.« less

Sweeping shunted electro-magnetic tuneable vibration absorber: Design and implementation

NASA Astrophysics Data System (ADS)

Turco, E.; Gardonio, P.

2017-10-01

This paper presents a study on the design and implementation of a time-varying shunted electro-magnetic Tuneable Vibration Absorber for broad-band vibration control of thin structures. A time-varying RL-shunt is used to harmonically vary the stiffness and damping properties of the Tuneable Vibration Absorber so that its mechanical fundamental natural frequency is continuously swept in a given broad frequency band whereas its mechanical damping is continuously adapted to maximize the vibration absorption from the hosting structure where it is mounted. The paper first recalls the tuning and positioning criteria for the case where a classical Tuneable Vibration Absorber is installed on a thin walled cylindrical structure to reduce the response of a resonating flexural mode. It then discusses the design of the time-varying shunt circuit to produce the desired stiffness and damping variations in the electro-magnetic Tuneable Vibration Absorber. Finally, it presents a numerical study on the flexural vibration and interior sound control effects produced when an array of these shunted electro-magnetic Tuneable Vibration Absorbers are mounted on a thin walled cylinder subject to a rain-on-the-roof stochastic excitation. The study shows that the array of proposed systems effectively controls the cylinder flexural response and interior noise over a broad frequency band without need of tuning and thus system identification of the structure. Therefore, the systems can be successfully used also on structures whose physical properties vary in time because of temperature changes or tensioning effects for example.

Candidal infections of ventriculoperitoneal shunts.

PubMed

Baradkar, V P; Mathur, M; Sonavane, A; Kumar, S

2009-07-01

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.

The effectiveness and efficiency of phytoremediation of a multicontaminated industrial site: Porto Marghera (Venice Lagoon, Italy).

PubMed

Guarino, C; Sciarrillo, R

2017-09-01

The Venice Lagoon is worldwide considered as a typical example of the human impact on the surrounding ecosystem. The development of the industrial zone of Porto Marghera begun in 1917 as an extension of the Venice Port, in order to sustain activities related to oil and coal, as well as to exploit the railway system. Despite the recent decrease in the number of employees, Porto Marghera is still one of the most important chemical districts in Italy. This study reports early results from the ongoing in-situ phytoextraction of potentially toxic elements (Cd, Hg, Zn) within the industrial area of Porto Marghera. Two agronomic plant species with high annual biomass yield (Helianthus annuus L., Brassica juncea (L.) Czern.) were used. This paper also reports the microcosms and mesocosms tests to evaluate the efficacy of the treatments to be applied to the in-situ phytoextraction process of the polluted site. The combined use of EDTA and Ammonium Thiosulfate during phytoextraction increases the efficiency of Cd, Hg, Zn removal from contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Internal carotid artery rupture caused by carotid shunt insertion

PubMed Central

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

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 arterial rupture at the distal tip of the shunt was detected and was repaired via a small saphenous vein patch. Eversion CEA and subsequent CABG completed the procedure whose postoperative course was uneventful. Discussion Shunting during combined CEA-CABG may be advisable to assure cerebral protection from possible hypoperfusion due to potential hemodynamic instability of patients with severe coronary artery disease. Awareness and prompt management of possible shunt-related complications, including the newly reported one, may contribute to limiting their harmful effect. Conclusion Arterial wall rupture is a possible, previously not reported, shunt-related complication to be aware of when performing CEA. PMID:26255001

Internal carotid artery rupture caused by carotid shunt insertion.

PubMed

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

2015-01-01

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

The Bohr Effect Is Not a Likely Promoter of Renal Preglomerular Oxygen Shunting

PubMed Central

Olgac, Ufuk; Kurtcuoglu, Vartan

2016-01-01

The aim of this study was to evaluate whether possible preglomerular arterial-to-venous oxygen shunting is affected by the interaction between renal preglomerular carbon dioxide and oxygen transport. We hypothesized that a reverse (venous-to-arterial) shunting of carbon dioxide will increase partial pressure of carbon dioxide and decrease pH in the arteries and thereby lead to increased oxygen offloading and consequent oxygen shunting. To test this hypothesis, we employed a segment-wise three-dimensional computational model of coupled renal oxygen and carbon dioxide transport, wherein coupling is achieved by shifting the oxygen-hemoglobin dissociation curve in dependence of local changes in partial pressure of carbon dioxide and pH. The model suggests that primarily due to the high buffering capacity of blood, there is only marginally increased acidity in the preglomerular vasculature compared to systemic arterial blood caused by carbon dioxide shunting. Furthermore, effects of carbon dioxide transport do not promote but rather impair preglomerular oxygen shunting, as the increase in acidity is higher in the veins compared to that in the arteries. We conclude that while substantial arterial-to-venous oxygen shunting might take place in the postglomerular vasculature, the net amount of oxygen shunted at the preglomerular vasculature appears to be marginal. PMID:27833564

Cranial dural arteriovenous shunts. Part 4. Clinical presentation of the shunts with leptomeningeal venous drainage.

PubMed

Baltsavias, Gerasimos; Spiessberger, Alex; Hothorn, Torsten; Valavanis, Anton

2015-04-01

Cranial dural arteriovenous fistulae have been classified into high- and low-risk lesions mainly based on the pattern of venous drainage. Those with leptomeningeal venous drainage carry a higher risk of an aggressive clinical presentation. Recently, it has been proposed that the clinical presentation should be considered as an additional independent factor determining the clinical course of these lesions. However, dural shunts with leptomeningeal venous drainage include a very wide spectrum of inhomogeneous lesions. In the current study, we correlated the clinical presentation of 107 consecutive patients harboring cranial dural arteriovenous shunts with leptomeningeal venous drainage, with their distinct anatomic and angiographic features categorized into eight groups based on the "DES" (Directness and Exclusivity of leptomeningeal venous drainage and features of venous Strain) concept. We found that among these groups, there are significant angioarchitectural differences, which are reflected by considerable differences in clinical presentation. Leptomeningeal venous drainage of dural sinus shunts that is neither direct nor exclusive and without venous strain manifested only benign symptoms (aggressive presentation 0%). On the other end of the spectrum, the bridging vein shunts with direct and exclusive leptomeningeal venous drainage and venous strain are expected to present aggressive symptoms almost always and most likely with bleeding (aggressive presentation 91.5%). Important aspects of the above correlations are discussed. Therefore, the consideration of leptomeningeal venous drainage alone, for prediction of the clinical presentation of these shunts appears insufficient. Angiographic analysis based on the above concept, offers the possibility to distinguish the higher- from the lower-risk types of leptomeningeal venous drainage. In this context, consideration of the clinical presentation as an additional independent factor for the prediction of their clinical

Impedance Changes Indicate Proximal Ventriculoperitoneal Shunt Obstruction In Vitro.

PubMed

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

2015-12-01

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

Tunable elastic parity-time symmetric structure based on the shunted piezoelectric materials

NASA Astrophysics Data System (ADS)

Hou, Zhilin; Assouar, Badreddine

2018-02-01

We theoretically and numerically report on the tunable elastic Parity-Time (PT) symmetric structure based on shunted piezoelectric units. We show that the elastic loss and gain can be archived in piezoelectric materials when they are shunted by external circuits containing positive and negative resistances. We present and discuss, as an example, the strongly dependent relationship between the exceptional points of a three-layered system and the impedance of their external shunted circuit. The achieved results evidence that the PT symmetric structures based on this proposed concept can actively be tuned without any change of their geometric configurations.

Congenital portosystemic shunt: our experience.

PubMed

Timpanaro, Tiziana; Passanisi, Stefano; Sauna, Alessandra; Trombatore, Claudia; Pennisi, Monica; Petrillo, Giuseppe; Smilari, Pierluigi; Greco, Filippo

2015-01-01

Introduction. Congenital portosystemic venous malformations are rare abnormalities in which the portal blood drains into a systemic vein and which are characterized by extreme clinical variability. Case Presentations. The authors present two case reports of a congenital extrahepatic portosystemic shunt (Type II). In the first patient, apparently nonspecific symptoms, such as headache and fatigue, proved to be secondary to hypoglycemic episodes related to the presence of a portosystemic shunt, later confirmed on imaging. During portal vein angiography, endovascular embolization of the portocaval fistula achieved occlusion of the anomalous venous tract. In the second patient, affected by Down's syndrome, the diagnosis of a portosystemic malformation was made by routine ultrasonography, performed to rule out concurrent congenital anomalies. Because of the absence of symptoms, we chose to observe this patient. Conclusions. These two case reports demonstrate the clinical heterogeneity of this malformation and the need for a multidisciplinary approach. As part of a proper workup, clinical evaluation must always be followed by radiographic diagnosis.

Congenital Portosystemic Shunt: Our Experience

PubMed Central

Timpanaro, Tiziana; Passanisi, Stefano; Sauna, Alessandra; Trombatore, Claudia; Pennisi, Monica; Petrillo, Giuseppe; Smilari, Pierluigi; Greco, Filippo

2015-01-01

Introduction. Congenital portosystemic venous malformations are rare abnormalities in which the portal blood drains into a systemic vein and which are characterized by extreme clinical variability. Case Presentations. The authors present two case reports of a congenital extrahepatic portosystemic shunt (Type II). In the first patient, apparently nonspecific symptoms, such as headache and fatigue, proved to be secondary to hypoglycemic episodes related to the presence of a portosystemic shunt, later confirmed on imaging. During portal vein angiography, endovascular embolization of the portocaval fistula achieved occlusion of the anomalous venous tract. In the second patient, affected by Down's syndrome, the diagnosis of a portosystemic malformation was made by routine ultrasonography, performed to rule out concurrent congenital anomalies. Because of the absence of symptoms, we chose to observe this patient. Conclusions. These two case reports demonstrate the clinical heterogeneity of this malformation and the need for a multidisciplinary approach. As part of a proper workup, clinical evaluation must always be followed by radiographic diagnosis. PMID:25709849

Sarcopenia Is Risk Factor for Development of Hepatic Encephalopathy After Transjugular Intrahepatic Portosystemic Shunt Placement.

PubMed

Nardelli, Silvia; Lattanzi, Barbara; Torrisi, Sabrina; Greco, Francesca; Farcomeni, Alessio; Gioia, Stefania; Merli, Manuela; Riggio, Oliviero

2017-06-01

Hepatic encephalopathy (HE) is an important complication in patients with cirrhosis who received transjugular intrahepatic portosystemic shunts (TIPS). We investigated whether a decrease in muscle mass was associated independently with the occurrence of HE after TIPS. We performed a prospective study of 46 consecutive patients with cirrhosis (mean age, 58.6 ± 9.1 y; mean model for end-stage liver disease score, 11.3 ± 3.3; mean Child-Pugh score, 7.6 ± 1.5) who received TIPS from January 2013 through December 2014 at a tertiary center in Rome, Italy. All patients underwent computed tomography analysis at the level of the third lumbar vertebrae to determine the skeletal muscle index; sarcopenia was defined by sex-specific cut-off values. We estimated the incidence of the first episode of HE after TIPS, taking into account the competing risk nature of the data (death or liver transplantation). Twenty-six patients (57%) were found to have sarcopenia. Twenty-one patients (46%) developed overt HE in the 7 ± 9 months after TIPS placement; all of these patients were sarcopenic, according to the skeletal muscle index. Of the 25 patients without HE after TIPS, only 5 had sarcopenia. In multivariate analysis, model for end-stage liver disease score (subdistribution hazard ratio, 1.16; 95% confidence interval, 1.01-1.34; P = .043) and sarcopenia (subdistribution hazard ratio, 31.3; 95% confidence interval, 4.5-218.07; P < .001) were associated independently with the development of HE after TIPS placement. In a prospective study of 46 patients with cirrhosis, we found muscle wasting, probably owing to reduced processing of ammonia, to be associated with the development of HE after TIPS placement. Sarcopenia should be considered in selecting patients for TIPS therapy. Nutritional status should be evaluated in patients with sarcopenia before TIPS placement, which might reduce the incidence of HE. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

A new shunt for obstructive hydrocephalus: ventricle-Sylvian fissure shunt A preliminary report.

PubMed

Patkar, Sushil

2017-06-01

Cerbrospinal fluid (CSF) pathway studies have revealed that after egressing from the fourth ventricle reaches the basal supra sellar cistern and ultimately the sylvian cisterns from where the CSF travels over the cerebral convexity subarachnoid space to reach the superior saggital sinus and enters the blood stream. Diverting CSF from the lateral ventricle with a shunt catheter to the sylvian cistern can be an option to treat obstructive hydrocephalus. 2 patients underwent this procedure of diverting CSF from the lateral ventricle with a shunt catheter (Chabbra, India) to the sylvian cistern successfully and had immediate relief of symptoms of raised intracranial pressure. Additional 4 patients had relief for 3mths to 6 mths and are under follow up. Though preliminary results seem logical and promising, more cases and longer follow-up is required to consider this shunt operation as an option in treatment of obstructive hydrocephalus.

Intracardiac Shunting and Stroke in Children: A Systematic Review

PubMed Central

Dowling, Michael M.; Ikemba, Catherine M.

2017-01-01

In adults, patent foramen ovale or other potential intracardiac shunts are established risk factors for stroke via paradoxical embolization. Stroke is less common in children and risk factors differ. The authors examined the literature on intracardiac shunting and stroke in children, identifying the methods employed, the prevalence of detectible intracardiac shunts, associated conditions, and treatments. PubMed searches with keywords related to intracardiac shunting and stroke in children identified articles of interest. Additional articles were identified via citations in these articles or in reviews. The authors found that studies of intracardiac shunting in children with stroke are limited. No controlled studies were identified. Detection methods vary and the prevalence of echocardiographically detectible intracardiac shunting appears lower than reported in adults and autopsy studies. Defining the role of intracardiac shunting in pediatric stroke will require controlled studies with unified detection methods in populations stratified by additional risk factors for paradoxical embolization. Optimal treatment is unclear. PMID:21212453

Hepatic vein transit time of second-generation ultrasound contrast agent: new tool in the assessment of portal hypertension.

PubMed

Luisa, Siciliani; Vitale, Giovanna; Sorbo, Anna Rita; Maurizio, Pompili; Lodovico, Rapaccini Gian

2017-03-01

It has been demonstrated that Doppler waveform of the hepatic vein (normally triphasic) is transformed into a biphasic or monophasic waveform in cirrhotic patients. The compressive mechanism of liver tissue has been considered up till now the cause of this change. Moreover, cirrhotics show, after USCA injection, a much earlier HVTT due to intrahepatic shunts. Our aim was to prospectively evaluate the correlation between Doppler pattern of hepatic vein and HVTT of a second-generation USCA; we also correlated HVTT with the most common indexes of portal hypertension. We enrolled 38 participants: 33 cirrhotics and 5 healthy controls. Doppler shift signals were obtained from the right hepatic vein. To characterize the hepatic vein pattern, we used the hepatic vein waveform index (HVWI). This index becomes >1 with the appearance of the triphasic waveform. We recorded a clip from 20 s before to 2 min after a peripheral intravenous bolus injection of 2.4 ml of USCA (sulfur hexafluoride).The time employed by USCA to cross the liver from the hepatic artery and portal vein to the hepatic vein was defined as HA-HVTT and PV-HVTT, respectively. Cirrhotics with low HVWI showed an earlier transit time; participants with higher HVWI had a longer transit time ( p  < 0.001). HVTT was earlier as MELD, Child-Pugh score and spleen diameter increased. Patients with ascites and varices of large size had significantly shorter transit times. Abnormal hepatic vein Doppler waveform in cirrhotic patients could be due to intrahepatic shunts. HVTT could be useful in the non-invasive evaluation of portal hypertension.

Insight into congenital absence of the portal vein: Is it rare?

PubMed Central

Shen, Guo-Hua Hu‚ Lai-Gen; Zhu, Jin Yang‚ Jin-Hua Mei‚ Yue-Feng

2008-01-01

Congenital absence of portal vein (CAPV) was a rare event in the past. However, the number of detected CAPV cases has increased in recent years because of advances in imaging techniques. Patients with CAPV present with portal hypertension (PH) or porto-systemic encephalopathy (PSE), but these conditions rarely occur until the patients grow up or become old. The patients usually visit doctors for the complications of venous shunts, hepatic or cardiac abnormalities detected by ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). The etiology of this disease is not clear, but most investigators consider that it is associated with abnormal embryologic development of the portal vein. Usually, surgical intervention can relieve the symptoms and prevent occurrence of complications in CAPV patients. Moreover, its management should be stressed on a case-by-case basis, depending on the type or anatomy of the disease, as well as the symptoms and clinical conditions of the patient. PMID:18932274

Effects of raloxifene on portal hypertension and hepatic encephalopathy in cirrhotic rats.

PubMed

Chang, Ching-Chih; Lee, Wen-Shin; Chuang, Chiao-Lin; Hsin, I-Fang; Hsu, Shao-Jung; Chang, Ting; Huang, Hui-Chun; Lee, Fa-Yauh; Lee, Shou-Dong

2017-05-05

Raloxifene, a selective estrogen receptor modulator, has been used extensively for osteoporosis. In addition to the effect of osteoporosis treatment, emerging evidences show that raloxifene affects the vascular function in different tissues. Cirrhosis is characterized with portal hypertension and complicated with hepatic encephalopathy. Portal hypertension affects portal-systemic shunt which leads to hepatic encephalopathy that the vascular modulation might influence severity of hepatic encephalopathy. Herein, we evaluated the impact of raloxifene on bile duct ligation (BDL)-induced cirrhotic rats. The female Sprague-Dawley rats received BDL plus ovariectomy or sham-operation. Four weeks later, rats were divided into 2 subgroups respectively to receive of raloxifene (10mg/kg/day) or saline (vehicle) for 14 days. On the 43th day, motor activities and hemodynamic parameters were measured. Hepatic and vascular mRNA and protein expressions were determined. The histopathological change of liver was examined. We found that the liver biochemistry, ammonia level and motor activity were similar between cirrhotic rats with or without raloxifene administration. The hemodynamic parameters were not significantly different except that raloxifene reduced portal venous inflow. Raloxifene exacerbated hepatic fibrosis and up-regulated hepatic endothelin-1 and cyclooxygenase 2 protein expressions. In addition, raloxifene modulated the mRNA expressions of endothelial nitric oxide synthase, cyclooxygenase and endothelin-1 in the superior mesenteric artery and collateral vessel. In conclusion, raloxifene aggravates hepatic fibrosis and decreases portal venous inflow in cirrhotic rats without adversely affecting portal hypertension and hepatic encephalopathy. The modulation of hepatic and vascular endothelin-1, endothelial nitric oxide synthase and cyclooxygenase expressions may play a role in the mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

Automatic Railway Traffic Object Detection System Using Feature Fusion Refine Neural Network under Shunting Mode.

PubMed

Ye, Tao; Wang, Baocheng; Song, Ping; Li, Juan

2018-06-12

Many accidents happen under shunting mode when the speed of a train is below 45 km/h. In this mode, train attendants observe the railway condition ahead using the traditional manual method and tell the observation results to the driver in order to avoid danger. To address this problem, an automatic object detection system based on convolutional neural network (CNN) is proposed to detect objects ahead in shunting mode, which is called Feature Fusion Refine neural network (FR-Net). It consists of three connected modules, i.e., the depthwise-pointwise convolution, the coarse detection module, and the object detection module. Depth-wise-pointwise convolutions are used to improve the detection in real time. The coarse detection module coarsely refine the locations and sizes of prior anchors to provide better initialization for the subsequent module and also reduces search space for the classification, whereas the object detection module aims to regress accurate object locations and predict the class labels for the prior anchors. The experimental results on the railway traffic dataset show that FR-Net achieves 0.8953 mAP with 72.3 FPS performance on a machine with a GeForce GTX1080Ti with the input size of 320 × 320 pixels. The results imply that FR-Net takes a good tradeoff both on effectiveness and real time performance. The proposed method can meet the needs of practical application in shunting mode.

Modelling the photochemical pollution over the metropolitan area of Porto Alegre, Brazil

NASA Astrophysics Data System (ADS)

Borrego, C.; Monteiro, A.; Ferreira, J.; Moraes, M. R.; Carvalho, A.; Ribeiro, I.; Miranda, A. I.; Moreira, D. M.

2010-01-01

The main purpose of this study is to evaluate the photochemical pollution over the Metropolitan Area of Porto Alegre (MAPA), Brazil, where high concentrations of ozone have been registered during the past years. Due to the restricted spatial coverage of the monitoring air quality network, a numerical modelling technique was selected and applied to this assessment exercise. Two different chemistry-transport models - CAMx and CALGRID - were applied for a summer period, driven by the MM5 meteorological model. The meteorological model performance was evaluated comparing its results to available monitoring data measured at the Porto Alegre airport. Validation results point out a good model performance. It was not possible to evaluate the chemistry models performance due to the lack of adequate monitoring data. Nevertheless, the model intercomparison between CAMx and CALGRID shows a similar behaviour in what concerns the simulation of nitrogen dioxide, but some discrepancies concerning ozone. Regarding the fulfilment of the Brazilian air quality targets, the simulated ozone concentrations surpass the legislated value in specific periods, mainly outside the urban area of Porto Alegre. The ozone formation is influenced by the emission of pollutants that act as precursors (like the nitrogen oxides emitted at Porto Alegre urban area and coming from a large refinery complex) and by the meteorological conditions.

Effect of Increased Intra-abdominal Pressure on Liver Histology and Hemodynamics: An Experimental Study.

PubMed

Antoniou, Efstathios A; Kairi, Evi; Margonis, Georgios A; Andreatos, Nikolaos; Sasaki, Kazunari; Damaskos, Christos; Garmpis, Nikolaos; Samaha, Mario; Argyra, Eriphyli; Polymeneas, George; Weiss, Matthew J; Pawlik, Timothy M; Voros, Dionysios; Kouraklis, Gregory

2018-01-01

While reduction of portal venous (PV) blood flow has been described in animal models of intra-abdominal hypertension, reports on compensatory changes in hepatic arterial (HA) flow, known as the hepatic arterial buffer response are controversial. Pneumoperitoneum with helium was induced in 13 piglets. Hemodynamic measurements and pathological assessment were conducted at baseline and during the three subsequent phases: Phase A: 45 minutes with a stable intra-abdominal pressure of 25 mmHg; phase B: 45 minutes with a stable intra-abdominal pressure of 40 mmHg; and phase C during which the abdomen was re-explored and reperfusion of the liver was allowed to take place. Phase B pressure was significantly greater than phase A pressure in both the PV and the inferior vena cava, demonstrating a positive association between escalating intra-abdominal hypertension and the pressure in these two vessels (all p<0.001). In contrast, HA pressure was comparable between baseline and phase A, while it tended to decrease in phase B. Regarding histology, the most notable abnormality was the presence of inflammatory infiltrates and hepatocyte necrosis. Helium-insufflation increased PV pressure with a partial compensatory decrease of HA pressure. Nonetheless, findings consistent with hepatic ischemia were observed on pathology. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Organ distribution of 13N following intravenous injection of [13N]ammonia into portacaval-shunted rats

PubMed Central

Cruz, Nancy F.; Dienel, Gerald A.; Patrick, Tricia A.; Cooper, Arthur J. L.

2016-01-01

Ammonia is neurotoxic, and chronic hyperammonemia is thought to be a major contributing factor to hepatic encephalopathy in patients with liver disease. Portacaval shunting of rats is used as an animal model to study the detrimental metabolic effects of elevated ammonia levels on body tissues, particularly brain and testes that are deleteriously targeted by high blood ammonia. In normal adult rats, the initial uptake of label (expressed as relative concentration) in these organs was relatively low following a bolus intravenous injection of [13N]ammonia compared with lungs, kidneys, liver, and some other organs. The objective of the present study was to determine the distribution of label following intravenous administration of [13N]ammonia among 14 organs in portacaval-shunted rats at 12 weeks after shunt construction. At an early time point (12 sec) following administration of [13N]ammonia the relative concentration of label was highest in lung with lower, but still appreciable relative concentrations in kidney and heart. Clearance of 13N from blood and kidney tended to be slower in portacaval-shunted rats versus normal rats during the 2–10 min interval after the injection. At later times post injection, brain and testes tended to have higher-than-normal 13N levels, whereas many other tissues had similar levels in both groups. Thus, reduced removal of ammonia from circulating blood by the liver diverts more ammonia to extrahepatic tissues, including brain and testes, and alters the nitrogen homeostasis in these tissues. These results emphasize the importance of treatment paradigms designed to reduce blood ammonia levels in patients with liver disease. PMID:27822667

Organ Distribution of 13N Following Intravenous Injection of [13N]Ammonia into Portacaval-Shunted Rats.

PubMed

Cruz, Nancy F; Dienel, Gerald A; Patrick, Patricia A; Cooper, Arthur J L

2017-06-01

Ammonia is neurotoxic, and chronic hyperammonemia is thought to be a major contributing factor to hepatic encephalopathy in patients with liver disease. Portacaval shunting of rats is used as an animal model to study the detrimental metabolic effects of elevated ammonia levels on body tissues, particularly brain and testes that are deleteriously targeted by high blood ammonia. In normal adult rats, the initial uptake of label (expressed as relative concentration) in these organs was relatively low following a bolus intravenous injection of [ 13 N]ammonia compared with lungs, kidneys, liver, and some other organs. The objective of the present study was to determine the distribution of label following intravenous administration of [ 13 N]ammonia among 14 organs in portacaval-shunted rats at 12 weeks after shunt construction. At an early time point (12 s) following administration of [ 13 N]ammonia the relative concentration of label was highest in lung with lower, but still appreciable relative concentrations in kidney and heart. Clearance of 13 N from blood and kidney tended to be slower in portacaval-shunted rats versus normal rats during the 2-10 min interval after the injection. At later times post injection, brain and testes tended to have higher-than-normal 13 N levels, whereas many other tissues had similar levels in both groups. Thus, reduced removal of ammonia from circulating blood by the liver diverts more ammonia to extrahepatic tissues, including brain and testes, and alters the nitrogen homeostasis in these tissues. These results emphasize the importance of treatment paradigms designed to reduce blood ammonia levels in patients with liver disease.

Laparoscopic correction of congenital portosystemic shunt in children.

PubMed

Kimura, Takuya; Soh, Hideki; Hasegawa, Toshimichi; Sasaki, Takashi; Kuroda, Seika; Yuri, Etani; Tomoda, Kaname; Fukuzawa, Masahiro

2004-10-01

Congenital portosystemic shunt is a rare clinical entity that may progress to jaundice, severe encephalopathy, and pulmonary hypertension and require surgical correction or coil embolization. We present a novel approach to the management of children with congenital portosystemic shunt by means of a minimally invasive surgical technique. Congenital portosystemic shunts were identified between the superior mesenteric vein and inferior vena cava in case 1 and between the splenic vein and left renal vein in case 2. Both of them were successfully ligated by laparoscopic approach, and catheters were subsequently replaced to monitor portal venous pressure. The patients tolerated the procedure well, and short-term results were excellent. Laparoscopic ligation of congenital portosystemic shunt is technically feasible and less invasive to the management of patients with congenital portosystemic shunts, preventing late onset, life-threatening complications.

Therapeutic approaches for portal biliopathy: A systematic review

PubMed Central

Franceschet, Irene; Zanetto, Alberto; Ferrarese, Alberto; Burra, Patrizia; Senzolo, Marco

2016-01-01

Portal biliopathy (PB) is defined as the presence of biliary abnormalities in patients with non-cirrhotic/non-neoplastic extrahepatic portal vein obstruction (EHPVO) and portal cavernoma (PC). The pathogenesis of PB is due to ab extrinseco compression of bile ducts by PC and/or to ischemic damage secondary to an altered biliary vascularization in EHPVO and PC. Although asymptomatic biliary abnormalities can be frequently seen by magnetic resonance cholangiopancreatography in patients with PC (77%-100%), only a part of these (5%-38%) are symptomatic. Clinical presentation includes jaundice, cholangitis, cholecystitis, abdominal pain, and cholelithiasis. In this subset of patients is required a specific treatment. Different therapeutic approaches aimed to diminish portal hypertension and treat biliary strictures are available. In order to decompress PC, surgical porto-systemic shunt or transjugular intrahepatic porto-systemic shunt can be performed, and treatment on the biliary stenosis includes endoscopic (Endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy, balloon dilation, stone extraction, stent placement) and surgical (bilioenteric anastomosis, cholecystectomy) approaches. Definitive treatment of PB often requires multiple and combined interventions both on vascular and biliary system. Liver transplantation can be considered in patients with secondary biliary cirrhosis, recurrent cholangitis or unsuccessful control of portal hypertension. PMID:28018098

Realization of a Λ System with Metastable States of a Capacitively Shunted Fluxonium

NASA Astrophysics Data System (ADS)

Earnest, N.; Chakram, S.; Lu, Y.; Irons, N.; Naik, R. K.; Leung, N.; Ocola, L.; Czaplewski, D. A.; Baker, B.; Lawrence, Jay; Koch, Jens; Schuster, D. I.

2018-04-01

We realize a Λ system in a superconducting circuit, with metastable states exhibiting lifetimes up to 8 ms. We exponentially suppress the tunneling matrix elements involved in spontaneous energy relaxation by creating a "heavy" fluxonium, realized by adding a capacitive shunt to the original circuit design. The device allows for both cavity-assisted and direct fluorescent readouts, as well as state preparation schemes akin to optical pumping. Since direct transitions between the metastable states are strongly suppressed, we utilize Raman transitions for coherent manipulation of the states.

Treatment of refractory chylothorax with externalized pleuroperitoneal shunts in children.

PubMed

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

1999-09-01

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

Ventriculoperitoneal shunt infection in Haji Adam Malik Hospital, Medan

NASA Astrophysics Data System (ADS)

Dharmajaya, R.

2018-03-01

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

Petroleum systems of the Po Basin Province of northern Italy and the northern Adriatic Sea; Porto Garibaldi (biogenic), Meride/Riva di Solto (thermal), and Marnoso Arenacea (thermal)

USGS Publications Warehouse

Lindquist, Sandra J.

1999-01-01

The Porto Garibaldi total petroleum system dominates the Po Basin Province of onshore northern Italy and offshore Italy and Croatia in the northern Adriatic Sea. Porto Garibaldi contains Pliocene (primarily) and Pleistocene (secondarily) biogenic gas ? approximately 16 TCF (2.66 BBOE) ultimately recoverable ? accumulated in co-eval siliciclastic reservoirs. This area was the northwestern edge of the Gondwanan (African) continental plate in pre-Hercynian time until the assembly of Pangea, a dominantly carbonate passive continental margin during the Mesozoic breakup of Pangea, and a Cenozoic collision zone with siliciclastic foredeep and foreland regions surrounded by thrust belts. At least two other petroleum systems, with Triassic (Meride / Riva di Solto) and Miocene (Marnoso Arenacea) source rocks, contribute oil and thermal gas reserves (nearly 1 BBOE) to the province. The major time of hydrocarbon expulsion of the thermal systems was Late Neogene during the Alpine and Apennine orogenies. Local Mesozoic oil expulsion from Triassic rocks also occurred, but those oils either were not trapped or were leaked from faulty traps through time.

Association between right-to-left shunts and brain lesions in sport divers.

PubMed

Gerriets, Tibo; Tetzlaff, Kay; Hutzelmann, Alfred; Liceni, Thomas; Kopiske, Gerrit; Struck, Niklas; Reuter, Michael; Kaps, Manfred

2003-10-01

Recent studies suggest that healthy sport divers may develop clinically silent brain damage, based on the association between a finding of multiple brain lesions on MRI and the presence of right-to-left shunt, a pathway for venous gas bubbles to enter the arterial system. We performed echocontrast transcranial Doppler sonography in 42 sport divers to determine the presence of a right-to-left shunt. Cranial MRI was carried out using a 1.5 T magnet. A lesion was counted if it was hyperintense on both T2-weighted and T2-weighted fluid attenuated inversion recovery sequences. To test the hypothesis that the occurrence of postdive arterial gas emboli is related to brain lesions on MRI, we measured postdive intravascular bubbles in a subset of 15 divers 30 min after open water scuba dives. Echocontrast transcranial Doppler sonography revealed a right-to-left shunt in 16 of the divers (38%). Only one hyperintensive lesion of the central white matter was found and that was in a diver with no evidence of a right-to-left shunt. Postdive arterial gas emboli were detected in 3 out of 15 divers; they had a right-to-left shunt, but no pathologic findings on cranial magnetic resonance imaging. Our data support the theory that right-to-left shunts can serve as a pathway for venous gas bubbles into the arterial circulation. However, we could not confirm an association between brain lesions and the presence of a right-to-left shunt in sport divers.

Plasma Glucose Level Is Predictive of Serum Ammonia Level After Retrograde Occlusion of Portosystemic Shunts.

PubMed

Ishikawa, Tsuyoshi; Aibe, Yuki; Matsuda, Takashi; Iwamoto, Takuya; Takami, Taro; Sakaida, Isao

2017-09-01

The purpose of this study was to evaluate predictors of reduction in ammonia levels by occlusion of portosystemic shunts (PSS) in patients with cirrhosis. Forty-eight patients with cirrhosis (21 women, 27 men; mean age, 67.8 years) with PSS underwent balloon-occluded retrograde transvenous obliteration (BRTO) at one institution between February 2008 and June 2014. The causes of cirrhosis were hepatitis B in one case, hepatitis C in 20 cases, alcohol in 15 cases, nonalcoholic steatohepatitis in eight cases, and other conditions in four cases. The Child-Pugh classes were A in 24 cases, B in 23 cases, and C in one case. The indication for BRTO was gastric varices in 40 cases and hepatic encephalopathy in eight cases. Testing was conducted before and 1 month after the procedure. Statistical analyses were performed to identify predictors of a clinically significant decline in ammonia levels after BRTO. Occlusion of PSS resulted in a clinically significant decrease in ammonia levels accompanied by increased portal venous flow and improved Child-Pugh score. Univariate analyses showed that a reduction in ammonia levels due to BRTO was significantly related to lower plasma glucose levels, higher RBC counts, and higher hemoglobin concentration before the treatment. Furthermore, multivariate logistic regression identified preoperative plasma glucose level as the strongest independent predictor of a significant ammonia reduction in response to BRTO. In addition, although BRTO resulted in significantly declined ammonia levels in patients with normal glucose tolerance before the procedure, ammonia levels were not significantly decreased after shunt occlusion in patients with diabetes mellitus or impaired glucose tolerance before BRTO, according to 75-g oral glucose tolerance test results. Preoperative plasma glucose level is a useful predictor of clinically significant ammonia reduction resulting from occlusion of PSS in patients with cirrhosis. Even if PSS are present, control

Refractory hepatic encephalopathy in a patient with hypothyroidism: Another element in ammonia metabolism

PubMed Central

Díaz-Fontenla, Fernando; Castillo-Pradillo, Marta; Díaz-Gómez, Arantxa; Ibañez-Samaniego, Luis; Gancedo, Pilar; Guzmán-de-Villoria, Juan Adan; Fernández-García, Pilar; Bañares-Cañizares, Rafael; García-Martínez, Rita

2017-01-01

Hepatic encephalopathy (HE) remains a diagnosis of exclusion due to the lack of specific signs and symptoms. Refractory HE is an uncommon but serious condition that requires the search of hidden precipitating events (i.e., portosystemic shunt) and alternative diagnosis. Hypothyroidism shares clinical manifestations with HE and is usually considered within the differential diagnosis of HE. Here, we describe a patient with refractory HE who presented a large portosystemic shunt and post-ablative hypothyroidism. Her cognitive impairment, hyperammonaemia, electroencephalograph alterations, impaired neuropsychological performance, and magnetic resonance imaging and spectroscopy disturbances were highly suggestive of HE, paralleled the course of hypothyroidism and normalized after thyroid hormone replacement. There was no need for intervention over the portosystemic shunt. The case findings support that hypothyroidism may precipitate HE in cirrhotic patients by inducing hyperammonaemia and/or enhancing ammonia brain toxicity. This case led us to consider hypothyroidism not only in the differential diagnosis but also as a precipitating factor of HE. PMID:28811719

Refractory hepatic encephalopathy in a patient with hypothyroidism: Another element in ammonia metabolism.

PubMed

Díaz-Fontenla, Fernando; Castillo-Pradillo, Marta; Díaz-Gómez, Arantxa; Ibañez-Samaniego, Luis; Gancedo, Pilar; Guzmán-de-Villoria, Juan Adan; Fernández-García, Pilar; Bañares-Cañizares, Rafael; García-Martínez, Rita

2017-07-28

Hepatic encephalopathy (HE) remains a diagnosis of exclusion due to the lack of specific signs and symptoms. Refractory HE is an uncommon but serious condition that requires the search of hidden precipitating events ( i.e ., portosystemic shunt) and alternative diagnosis. Hypothyroidism shares clinical manifestations with HE and is usually considered within the differential diagnosis of HE. Here, we describe a patient with refractory HE who presented a large portosystemic shunt and post-ablative hypothyroidism. Her cognitive impairment, hyperammonaemia, electroencephalograph alterations, impaired neuropsychological performance, and magnetic resonance imaging and spectroscopy disturbances were highly suggestive of HE, paralleled the course of hypothyroidism and normalized after thyroid hormone replacement. There was no need for intervention over the portosystemic shunt. The case findings support that hypothyroidism may precipitate HE in cirrhotic patients by inducing hyperammonaemia and/or enhancing ammonia brain toxicity. This case led us to consider hypothyroidism not only in the differential diagnosis but also as a precipitating factor of HE.

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

Realization of a Λ System with Metastable States of a Capacitively Shunted Fluxonium.

PubMed

Earnest, N; Chakram, S; Lu, Y; Irons, N; Naik, R K; Leung, N; Ocola, L; Czaplewski, D A; Baker, B; Lawrence, Jay; Koch, Jens; Schuster, D I

2018-04-13

We realize a Λ system in a superconducting circuit, with metastable states exhibiting lifetimes up to 8 ms. We exponentially suppress the tunneling matrix elements involved in spontaneous energy relaxation by creating a "heavy" fluxonium, realized by adding a capacitive shunt to the original circuit design. The device allows for both cavity-assisted and direct fluorescent readouts, as well as state preparation schemes akin to optical pumping. Since direct transitions between the metastable states are strongly suppressed, we utilize Raman transitions for coherent manipulation of the states.

Normal pressure hydrocephalus: long-term outcome after shunt surgery.

PubMed

Pujari, S; Kharkar, S; Metellus, P; Shuck, J; Williams, M A; Rigamonti, D

2008-11-01

Little is known about the long-term clinical course and management of patients with normal pressure hydrocephalus (NPH) treated by cerebrospinal fluid (CSF) shunting. We retrospectively reviewed records of 55 patients diagnosed with idiopathic NPH (INPH) and treated with CSF shunts, all of whom were followed for more than 3 years after the original shunt surgery. At each annual follow-up visit, the patient was assessed by Folstein Mini Mental State Examination, detailed clinical evaluation of gait and assessment of headache, cognition, gait or urination, as assessed by the patient and relatives. The mean duration of follow-up was 5.9+/-2.5 years. There was an overall sustained improvement among all symptoms. Gait showed the highest maintenance of improvement over baseline (83% at 3 years and 87% at the last analysed follow-up of 7 years), cognition showed intermediary improvement (84% and 86%, respectively), and urinary incontinence showed the least improvement (84% and 80%, respectively). Fifty-three percent of patients required shunt revisions. Indications for revision included shunt malfunction (87%), infection (10%) and change of shunt configuration (3%). Overall, 74% revisions resulted in clinical improvement. Clinical improvement of patients with NPH can be sustained for 5-7 years in some patients with NPH, even if shunt revision surgery is needed multiple times. With earlier diagnosis and treatment of NPH and the increasing lifespan of the ageing population, the need for long-term follow-up after shunt surgery for NPH may be greater than it was in the past. Monitoring, identification and treatment of shunt obstruction is a key management principle.

Should ventriculoatrial shunting be the procedure of choice for normal-pressure hydrocephalus?

PubMed

McGovern, Robert A; Kelly, Kathleen M; Chan, Andrew K; Morrissey, Nicholas J; McKhann, Guy M

2014-06-01

Ventriculoatrial (VA) shunting is rarely used for patients with normal-pressure hydrocephalus (NPH), likely due to surgeon technical preference and case reports indicating cardiopulmonary complications. However, these complications have typically been limited to adults in whom VA shunts had been placed when they were children. Few studies have directly compared VA shunting to ventriculoperitoneal (VP) shunting in cases of NPH. The authors retrospectively analyzed all NPH patients treated by a single surgeon at their center from January 2002 through December 2011. Thirty patients were treated with VA shunts (14 male) and 157 with VP shunts (86 male). The patients' mean age (± SD) at surgery was 73.7 ± 9.4 years for VA shunting and 76.0 ± 8.2 years for VP shunting; the median durations of follow-up were 42.0 months (IQR 19.2-63.6 months) and 34.2 months (IQR 15.8-67.5), respectively. Statistical analysis was performed using chi-square tests and Wilcoxon rank-sum tests. Perioperative and postoperative complications for VA and VP shunting cohorts, respectively, included distal revision (2.7% vs 6.6%, p = 0.45), proximal revision (2.7% vs 2.5%, p = 0.97), and postoperative seizure (2.7% vs 1.5%, p = 0.62). Shunt drainage-related subdural hematomas/hygromas developed in 8.1%/27.0% of VA shunt-treated patients versus 6.6%/26.4% of VP shunt-treated patients (p = 0.76/0.98) and were nearly always successfully managed with programmable-valve adjustment. Symptomatic intracerebral hemorrhage (1.5%) and shunt infection (2.0%) were only observed in those who underwent VP shunting. Of note, no cardiovascular complications were observed in any patient, and there were no cases of distal occlusion of the VA shunt. The authors found no significant differences in complication rates between VA and VP shunting, and VA shunting was not associated with any cardiopulmonary complications. Thus, in the authors' experience, VA shunting is at least as safe as VP shunting for treating NPH.

Accessory hepatic vein complicating extra-cardiac total cavopulmonary connection.

PubMed

Yoshii, Shinpei; Suzuki, Shoji; Osawa, Hiroshi; Hosaka, Shigeru; Honda, Yoshihiro; Abraham, Samuel J K; Tada, Yusuke; Sugiyama, Hisashi; Tan, Tetsushi; Kadono, Toshie; Hoshiai, Minako; Komai, Takayuki

2002-04-01

We encountered unexpected, severe hypoxia after the right heart bypass operation in a patient with isomerism. A 2-year-old girl with polysplenia had a complex cardiac anomaly consisting of a single atrium, single ventricle, pulmonary stenosis, absence of the right superior vena cava, hemiazygos continuation of the left inferior vena cava, and d-malposition of the great arteries. After a total cavopulmonary shunt, we performed an extra-cardiac total cavo-pulmonary connection with a 14 mm tube graft. The postoperative course was complicated by severe hypoxia. Angiography performed 20 days after the operation showed that contrast medium in the conduit poured into the hepatic vein, and through the intrahepatic communications, it passed into a left-sided accessory hepatic vein, which was connected directly to the left side of the aspect of the atrium. As the intrahepatic communication was adequate, we ligated the accessory hepatic vein within the pericardial cavity. The SpO2 returned to normal and no hepatic dysfunction was detected. We conclude that surgeons performing extra-cardiac total cavopulmonary connection need to pay closer attention to the possibility that an accessory hepatic vein might exist.

Effects of Different Levels of Intra-Abdominal Pressure on the Postoperative Hepatic Function of Patients Undergoing Laparoscopic Cholecystectomy: A Systematic Review and Meta-Analysis.

PubMed

Cheng, Zheng-Jun; Wang, Yun-Bing; Chen, Long; Gong, Jian-Ping; Zhang, Wei

2018-04-18

The aim of this meta-analysis is to compare the differences in postoperative markers of the hepatic function under different intra-abdominal pressures in laparoscopic cholecystectomy (LC). Several databases were searched for control studies, and then the weighted data were pooled with random-effect models. A total of 11 studies involving 865 patients were included. The meta-analysis reveals that the level of the aspartate aminotransferase and alanine transaminase of the low-pressure group has a lower postoperative increase than the moderate-pressure group (P<0.001). The level of the aspartate aminotransferase and alanine transaminase of the moderate-pressure group has a lower postoperative increase than the high-pressure group (P<0.001). Totally, the effect of lower pressure LC on postoperative hepatic functions is less significant than that of the higher one. Potential subgroup analysis does not modify these results. The recommended pressure in LC is suggested to be lower so as to result in a better surgical safety, especially for special populations.

Maladjustment of programmable ventricular shunt valves by inadvertent exposure to a common hospital device.

PubMed

Fujimura, R; Lober, R; Kamian, K; Kleiner, L

2018-01-01

Programmable ventricular shunt valves are commonly used to treat hydrocephalus. They can be adjusted to allow for varying amounts of cerebrospinal fluid (CSF) flow using an external magnetic programming device, and are susceptible to maladjustment from inadvertent exposure to magnetic fields. We describe the case of a 3-month-old girl treated for hydrocephalus with a programmable Strata TM II valve found at the incorrect setting on multiple occasions during her hospitalization despite frequent reprogramming and surveillance. We found that the Vocera badge, a common hands-free wireless communication system worn by our nursing staff, had a strong enough magnetic field to unintentionally change the shunt setting. The device is worn on the chest bringing it into close proximity to the shunt valve when care providers hold the baby, resulting in the maladjustment. Some commonly used medical devices have a magnetic field strong enough to alter programmable shunt valve settings. Here, we report that the magnetic field from the Vocera hands-free wireless communication system, combined with the worn position, results in shunt maladjustment for the Strata TM II valve. Healthcare facilities using the Vocera badges need to put protocols in place and properly educate staff members to ensure the safety of patients with Strata TM II valves.

Optomechatronic System For Automated Intra Cytoplasmic Sperm Injection

NASA Astrophysics Data System (ADS)

Shulev, Assen; Tiankov, Tihomir; Ignatova, Detelina; Kostadinov, Kostadin; Roussev, Ilia; Trifonov, Dimitar; Penchev, Valentin

2015-12-01

This paper presents a complex optomechatronic system for In-Vitro Fertilization (IVF), offering almost complete automation of the Intra Cytoplasmic Sperm Injection (ICSI) procedure. The compound parts and sub-systems, as well as some of the computer vision algorithms, are described below. System capabilities for ICSI have been demonstrated on infertile oocyte cells.

Reduction of ventricular size after shunting for normal pressure hydrocephalus related to CSF dynamics before shunting.

PubMed Central

Tans, J T; Poortvliet, D C

1988-01-01

Reduction of ventricular size was determined by repeated computed tomography in 30 adult patients shunted for normal pressure hydrocephalus (NPH) and related to the pressure-volume index (PVI) and resistance to outflow of cerebrospinal fluid (Rcsf) measured before shunting. Rapid and marked reduction of ventricular size (n = 10) was associated with a significantly lower PVI than slow and moderate to marked (n = 13) or minimal to mild reduction (n = 7). Otherwise no relationship could be found between the reduction of ventricular size and PVI or Rcsf. It is concluded that both rate and magnitude of reduction of ventricular size after shunting for NPH are extremely variable. High brain elasticity seems to be the best predictor of rapid and marked reduction. PMID:3379425

Hydrostatic and hydrodynamic considerations in shunted normal pressure hydrocephalus.

PubMed

de Jong, D A; Delwel, E J; Avezaat, C J

2000-01-01

Symptoms of overdrainage, a frequent complication following shunting procedures especially in patients with normal-pressure hydrocephalus (NPH), are presumed to be caused by siphoning: gravity-enhanced flow of cerebro spinal fluid (CSF) through shunts in upright position. A critical reappraisal of siphoning and overdrainage (OD) is presented considering the occurrence of subdural hygromas (SDH) encountered in a group of patients shunted for NPH. The patients participated in the multicentre Dutch NPH study: 101 NPH patients were randomised for treatment with shunts with low or medium-high working pressure. Treatment with shunts with low working pressure resulted in an increased incidence of SDH (iSDH). Current physiological concepts of overdrainage are discussed and criticised. A new theory is presented on the basis of general physiological considerations. The theoretical model proposed yields a revised explanation for the origin of extremely low ventricular pressure in the upright position found with overdrainage. The efficacy of siphoning-preventing shunts and subtemporal decompression is explored in the light of the proposed theory.

Prognostic capability of different liver disease scoring systems for prediction of early mortality after transjugular intrahepatic portosystemic shunt creation.

PubMed

Gaba, Ron C; Couture, Patrick M; Bui, James T; Knuttinen, M Grace; Walzer, Natasha M; Kallwitz, Eric R; Berkes, Jamie L; Cotler, Scott J

2013-03-01

To compare the performance of various liver disease scoring systems in predicting early mortality after transjugular intrahepatic portosystemic shunt (TIPS) creation. In this single-institution retrospective study, eight scoring systems were used to grade liver disease in 211 patients (male-to-female ratio = 131:80; mean age, 54 y) before TIPS creation from 1999-2011. Scoring systems included bilirubin level, Child-Pugh (CP) score, Model for End-Stage Liver Disease (MELD) and Model for End-Stage Liver Disease sodium (MELD-Na) score, Emory score, prognostic index (PI), Acute Physiology and Chronic Health Evaluation (APACHE) 2 score, and Bonn TIPS early mortality (BOTEM) score. Medical record review was used to identify 30-day and 90-day clinical outcomes. The relationship of scoring parameters with mortality outcomes was assessed with multivariate analysis, and the relative ability of systems to predict mortality after TIPS creation was evaluated by comparing area under receiver operating characteristic (AUROC) curves. TIPS were successfully created for variceal hemorrhage (n = 121), ascites (n = 72), hepatic hydrothorax (n = 15), and portal vein thrombosis (n = 3). All scoring systems had a significant association with 30-day and 90-day mortality (P<.050 in each case) on multivariate analysis. Based on 30-day and 90-day AUROC, MELD (0.878, 0.816) and MELD-Na (0.863, 0.823) scores had the best capability to predict early mortality compared with bilirubin (0.786, 0.749), CP (0.822, 0.771), Emory (0.786, 0.681), PI (0.854, 0.760), APACHE 2 (0.836, 0.735), and BOTEM (0.798, 0.698), with statistical superiority over bilirubin, Emory, and BOTEM scores. Several liver disease scoring systems have prognostic value for early mortality after TIPS creation. MELD and MELD-Na scores most effectively predict survival after TIPS creation. Copyright © 2013. Published by Elsevier Inc.

Interventional management of gastroduodenal lesions complicating intra-arterial hepatic chemotherapy.

PubMed

Proietti, Stefania; De Baere, Thierry; Bessoud, Bertrand; Doenz, Francesco; Qanadli, Salah Dine; Schnyder, Pierre; Denys, Alban

2007-08-01

Herein we report the efficacy of embolization of small patent gastric or duodenal vessels for treating gastroduodenal complications after hepatic arterial infusion therapy (HAIC). Catheter ports were implanted percutaneously from a femoral approach in three cases or surgically in the gastroduodenal artery in two cases. Acute abdominal pain developed on average after four HAIC courses of 5FU-oxaliplatin, mytomycin, oxaliplatin or fotemustine. Esophagogastroduodenoscopy showed gastroduodenal lesions (gastroduodenitis with or without ulcerations) in all cases. Despite the interruption of the HAIC, symptoms persisted and led to selective hepatic arteriography showing a patent right gastric artery (n = 4) or a recanalized gastroduodenal artery (n = 1) responsible for gastroduodenal misperfusion. Successful embolizations of the arteries responsible for gastroduodenal misperfusion (right gastric artery in four cases and gastroduodenal artery in one case) using 0.018 platinium coils relieved the patients' symptoms and allowed the HAIC to continue. In gastroduodenal complications of HAIC, a selective hepatic arteriography should be performed to search any artery responsible for the misperfusion of the toxic agent in the gastroduodenal area. Embolization of these arteries allowed the HAIC to be restored.

The actions of two sensory neuropeptides, substance P and calcitonin gene-related peptide, on the canine hepatic arterial and portal vascular beds.

PubMed Central

Withrington, P. G.

1992-01-01

1. The two peptides, calcitonin gene-related peptide (CGRP) and substance P (SP) were administered individually as bolus injections into the separately perfused hepatic arterial and portal vascular beds of the anaesthetized dog to assess their actions and relative molar potencies at these sites. 2. CGRP caused an immediate dose-related increase in hepatic arterial flow when injected close-arterially, reflecting a fall in resistance. This vasodilator effect was slightly increased by the prior administration of the selective beta 2-adrenoceptor antagonist, ICI 118,551. 3. On a molar basis, CGRP was more potent as an hepatic arterial vasodilator than the non-selective beta-adrenoceptor agonist, isoprenaline (Iso). 4. Intra-portal injection of CGRP also evoked hepatic arterial vasodilatation unaccompanied by other cardiovascular changes. 5. CGRP in doses up to 10 nmol had no effect on portal vascular resistance when administered intra-portally. 6. SP evoked a rapid, dose-related increase in hepatic arterial flow when injected intra-arterially. The molar ED50 for this hepatic vasodilatation was 40.2 fmol, significantly less than the ED50 for either CGRP or Iso. SP was the most potent hepatic arterial vasodilator yet examined. The vasodilator effect of SP was slightly potentiated by prior beta 2-adrenoceptor blockade. 7. SP caused hepatic arterial vasodilatation when administered by intra-portal injection; its absolute and relative potency was much reduced. 8. SP when injected intra-portally caused a graded increase in hepatic portal inflow resistance. The molar potency for this portal vasoconstriction was significantly greater than that for noradrenaline (NA); however, the maximum increase in portal resistance was significantly less to SP than to NA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1384909

Ascending transaqueductal cystoventriculoperitoneal shunting in Dandy-Walker malformation: technical note.

PubMed

Unal, Omer Faruk; Aras, Yavuz; Aydoseli, Aydin; Akcakaya, Mehmet Osman

2012-01-01

The optimal treatment for Dandy-Walker malformation is still controversial. Ventriculoperitoneal shunting, cystoperitoneal shunting or combinations are the most common surgical options in the management of this clinical entity. Endoscopic procedures like ventriculocystostomy, 3rd ventriculostomy or endoscopy-assisted shunt surgeries have become the focus of recent publications. We describe a new transcystic endoscopic technique, with the usage of a single ascending transaqueductal shunt catheter with additional holes, whereby both the posterior fossa cyst and supratentorial ventricular compartments are drained effectively. By using this new technique complications associated with combined shunting can be avoided. In addition, by equalizing the pressure within the supra- and infratentorial compartments, the upward or downward herniations associated with single-catheter shunting can be prevented. Copyright © 2013 S. Karger AG, Basel.

Radiographical findings in patients with liver cirrhosis and hepatic encephalopathy.

PubMed

Elwir, Saleh; Hal, Hassan; Veith, Joshua; Schreibman, Ian; Kadry, Zakiyah; Riley, Thomas

2016-08-01

Hepatic encephalopathy is a common complication encountered in patients with liver cirrhosis. Hepatic encephalopathy is not reflected in the current liver transplant allocation system. Correlation was sought between hepatic encephalopathy with findings detected on radiographic imaging studies and the patient's clinical profile. A retrospective analysis was conducted of patients with cirrhosis, who presented for liver transplant evaluation in 2009 and 2010. Patients with hepatocellular carcinoma, ejection fraction less than 60% and who had a TIPS (transjugular intrahepatic portosystemic shunting) procedure or who did not complete the evaluation were excluded. Statistical analysis was performed and variables found to be significant on univariate analysis (P < 0.05) were analysed by a multivariate logistic regression model. A total of 117 patients met the inclusion criteria and were divided into a hepatic encephalopathy group (n = 58) and a control group (n = 59). Univariate analysis found that a smaller portal vein diameter, smaller liver antero-posterior diameter, liver nodularity and use of diuretics or centrally acting medications showed significant correlation with hepatic encephalopathy. This association was confirmed for smaller portal vein, use of diuretics and centrally acting medications in the multivariate analysis. A decrease in portal vein diameter was associated with increased risk of encephalopathy. Identifying patients with smaller portal vein diameter may warrant screening for encephalopathy by more advanced psychometric testing, and more aggressive control of constipation and other factors that may precipitate encephalopathy. © The Author(s) 2015. Published by Oxford University Press and the Digestive Science Publishing Co. Limited.

Management and classification of type II congenital portosystemic shunts.

PubMed

Lautz, Timothy B; Tantemsapya, Niramol; Rowell, Erin; Superina, Riccardo A

2011-02-01

Congenital portosystemic shunts (PSS) with preserved intrahepatic portal flow (type II) present with a range of clinical signs. The indications for and benefits of repair of PSS remain incompletely understood. A more comprehensive classification may also benefit comparative analyses from different institutions. All children treated at our institution for type II congenital PSS from 1999 through 2009 were reviewed for presentation, treatment, and outcome. Ten children (7 boys) with type II PSS were identified at a median age of 5.5 years. Hyperammonemia with varying degrees of neurocognitive dysfunction occurred in 80%. The shunt arose from a branch of the portal vein (type IIa; n = 2), from the main portal vein (type IIb; n = 7), or from a splenic or mesenteric vein (type IIc; n = 1). Management included operative ligation (n = 6), endovascular occlusion (n = 3), or a combined approach (n = 1). Shunt occlusion was successful in all cases. Serum ammonia decreased from 130 ± 115 μmol/L preoperatively to 31 ± 15 μmol/L postoperatively (P = .03). Additional benefits included resolution of neurocognitive dysfunction (n = 3), liver nodules (n = 1), and vaginal bleeding (n = 1). Correction of type II PSS relieves a wide array of symptoms. Surgery is indicated for patients with clinically significant shunting. A refined classification system will permit future comparison of patients with similar physiology. Copyright © 2011 Elsevier Inc. All rights reserved.

Post ventriculoperitoneal shunt abdominal pseudocyst: Challenges posed in management.

PubMed

Hamid, Raashid; Baba, Aejaz A; Bhat, Nisar A; Mufti, Gowhar; Mir, Younis A; Sajad, Wani

2017-01-01

In patients with hydrocephalus, the abdominal cavity has been used for absorption of cerebrospinal fluid (CSF) since 1905. Ventriculoperitoneal (VP) shunt operation is followed by abdominal complications in about 5-47% cases. Abdominal CSF pseudo cyst is an uncommon, but well described complication. This survey was conducted to study the clinical profile and management of this entity. We present our experience with cases of CSF pseudo cyst in children. Retrospective analysis of 4 cases diagnosed to have abdominal pseudo cyst following VP shunt between 2008 and 2013. All the four cases were suspected clinically and diagnosis was confirmed by abdominal ultrasonography. In three patients, the cyst was multilocular and of varying size. Fourth one had a unilocular cyst at the lower end of VP shunt. All the four patients had features of varying degree raised intracranial pressure and a two patients had abdominal signs also. All the patients needed open exploration. Cyst fluid was drained and partial to complete excision of the cyst was done along with the repositioning of the shunt in abdominal cavity in three patients and exteriorization of shunt in one patient. Patients were followed for any further complication over a period of 1-year. Abdominal pseudo cyst is a rare complication after VP Shunt and could result in shunt malfunction or abdominal symptoms and signs. Whenever suspected it should be confirmed by imaging, followed by open exploration and repositioning of the shunt.

Post ventriculoperitoneal shunt abdominal pseudocyst: Challenges posed in management

PubMed Central

Hamid, Raashid; Baba, Aejaz A.; Bhat, Nisar A.; Mufti, Gowhar; Mir, Younis A.; Sajad, Wani

2017-01-01

Background: In patients with hydrocephalus, the abdominal cavity has been used for absorption of cerebrospinal fluid (CSF) since 1905. Ventriculoperitoneal (VP) shunt operation is followed by abdominal complications in about 5-47% cases. Abdominal CSF pseudo cyst is an uncommon, but well described complication. Aim: This survey was conducted to study the clinical profile and management of this entity. We present our experience with cases of CSF pseudo cyst in children. Materials and Methods: Retrospective analysis of 4 cases diagnosed to have abdominal pseudo cyst following VP shunt between 2008 and 2013. All the four cases were suspected clinically and diagnosis was confirmed by abdominal ultrasonography. Results: In three patients, the cyst was multilocular and of varying size. Fourth one had a unilocular cyst at the lower end of VP shunt. All the four patients had features of varying degree raised intracranial pressure and a two patients had abdominal signs also. All the patients needed open exploration. Cyst fluid was drained and partial to complete excision of the cyst was done along with the repositioning of the shunt in abdominal cavity in three patients and exteriorization of shunt in one patient. Patients were followed for any further complication over a period of 1-year. Conclusion: Abdominal pseudo cyst is a rare complication after VP Shunt and could result in shunt malfunction or abdominal symptoms and signs. Whenever suspected it should be confirmed by imaging, followed by open exploration and repositioning of the shunt. PMID:28413525

[Hepatic artery pseudoaneurysm: report of two cases].

PubMed

Tun-Abraham, Mauro Enrique; Martínez-Ordaz, José Luis; Romero-Hernández, Teodoro

2014-01-01

Hepatic pseudoaneurysm is rare and potentially fatal. It occurs as a consequence of injury to the vascular wall, erosion diathermy through clips, biliary leakage and secondary infection. The main symptom is intra-abdominal bleeding. To communicate the case of two patients with hepatic pseudoaneurysm. Case 1: We present a 43 year-old male with a history of grade IV liver injury due to blunt abdominal trauma and managed surgically. Case 2: A 67 year-old man with bile duct injury after laparoscopic cholecystectomy. Both patients presented with biliary leakage, abdominal sepsis and late intra-abdominal bleeding. Tomographic studies showed the lesion. Superselective embolization was performed proximal and distal to the lesion with good results. During follow-up, none of them showed signs of recurrent bleeding. Hepatic artery pseudoaneurysm is rare and usually secondary to bile duct injury associated with vascular injury after cholecystectomy or liver trauma. Arteriography with embolization is the best diagnostic and therapeutic procedure. Surgery is indicated for hemodynamically unstable patients, embolization failure or rebleeding. Early diagnosis reduces morbidity and mortality of this complication.

Decreasing flood risk perception in Porto Alegre - Brazil and its influence on water resource management decisions

NASA Astrophysics Data System (ADS)

Allasia, D. G.; Tassi, R.; Bemfica, D.; Goldenfum, J. A.

2015-06-01

Porto Alegre is the capital and largest city in the Brazilian state of Rio Grande do Sul in Southern Brazil with approximately 1.5 million inhabitants. The city lies on the eastern bank of the Guaiba Lake, formed by the convergence of five rivers and leading to the Lagoa dos Patos, a giant freshwater lagoon navigable by even the largest of ships. This river junction has become an important alluvial port as well as a chief industrial and commercial centre. However, this strategic location resulted in severe damage because of its exposure to flooding from the river system, affecting the city in the years 1873, 1928, 1936, 1941 and 1967. In order to reduce flood risk, a complex system of levees and pump stations was implemented during 1960s and 1970s. Since its construction, not a single large flood event occurred. However, in recent years, the levees in the downtown region of Porto Alegre were severally criticized by city planners and population. Several projects have been proposed to demolish the Mauá Wall due to the false perception of lack of flood risk. Similar opinions and reactions against flood infrastructure have been observed in other cities in Brazil, such as Itajaí and Blumenau, with disastrous consequences. This paper illustrates how the perception of flood risk in Porto Alegre has changed over recent years as a result of flood infrastructure, and how such changes in perceptions can influence water management decisions.

An in vitro lung model to assess true shunt fraction by multiple inert gas elimination.

PubMed

Varadarajan, Balamurugan; Vogt, Andreas; Hartwich, Volker; Vasireddy, Rakesh; Consiglio, Jolanda; Hugi-Mayr, Beate; Eberle, Balthasar

2017-01-01

The Multiple Inert Gas Elimination Technique, based on Micropore Membrane Inlet Mass Spectrometry, (MMIMS-MIGET) has been designed as a rapid and direct method to assess the full range of ventilation-to-perfusion (V/Q) ratios. MMIMS-MIGET distributions have not been assessed in an experimental setup with predefined V/Q-distributions. We aimed (I) to construct a novel in vitro lung model (IVLM) for the simulation of predefined V/Q distributions with five gas exchange compartments and (II) to correlate shunt fractions derived from MMIMS-MIGET with preset reference shunt values of the IVLM. Five hollow-fiber membrane oxygenators switched in parallel within a closed extracorporeal oxygenation circuit were ventilated with sweep gas (V) and perfused with human red cell suspension or saline (Q). Inert gas solution was infused into the perfusion circuit of the gas exchange assembly. Sweep gas flow (V) was kept constant and reference shunt fractions (IVLM-S) were established by bypassing one or more oxygenators with perfusate flow (Q). The derived shunt fractions (MM-S) were determined using MIGET by MMIMS from the retention data. Shunt derived by MMIMS-MIGET correlated well with preset reference shunt fractions. The in vitro lung model is a convenient system for the setup of predefined true shunt fractions in validation of MMIMS-MIGET.

Hydrocephalus and Shunts

MedlinePlus

... someone with Spina Bilda and shunted hydrocephalus. When making decisions, here is some helpful advice to families and health care providers: • Pay attention to a parent’s (and particularly mom’s) gut feeling ...

Overdrainage after ventriculoperitoneal shunting in a patient with a wide depressed skull bone defect: The effect of atmospheric pressure gradient.

PubMed

Zhou, Lixiang; Yu, Jinlu; Sun, Lichao; Han, Yanwu; Wang, Guangming

2016-01-01

In patients with traumatic brain injury, an effective approach for managing refractory intracranial hypertension is wide decompressive craniectomy. Postoperative hydrocephalus is a frequent complication requiring cerebrospinal fluid (CSF) diversion. A 50-year-old male who underwent decompressive craniectomy after traumatic brain injury. He developed hydrocephalus postoperatively, and accordingly we placed a ventriculoperitoneal shunt. However, an imbalance between the intra- and extra-cranial atmospheric pressures led to overdrainage, and he suffered cognitive disorders and extremity weakness. He remained supine for 5days to avoid the effect of gravity on CSF diversion. After 20days, we performed a cranioplasty using a titanium plate. The postoperative course was uneventful, and the patient achieved satisfactory recovery. The gravitational effect and the atmospheric pressure gradient effect are two factors associated in the ventriculoperitoneal (VP) shunt treatment of hydrocephalus for the patient who had decompressive craniectomy. These effects can be eliminated by supine bed rest and cranioplasty. We herein emphasize the efficacy of VP shunt, supine bed rest and cranioplasty in treating hydrocephalus patients who have undergone craniectomy. A flexible application of these procedures to change the gravitational effect and the atmospheric pressure gradient effect should promote a favorable outcome. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Congenital portosystemic shunt: characterization of a multisystem disease.

PubMed

Sokollik, Christiane; Bandsma, Robert H J; Gana, Juan C; van den Heuvel, Meta; Ling, Simon C

2013-06-01

Congenital portosystemic shunts (CPSSs) are rare but increasingly recognized as a cause of important multisystem morbidity. We present new cases and a systematic literature review and propose an algorithm for the identification and care of affected patients. We reviewed the charts of consecutive patients seen in our pediatric liver clinic between 2003 and 2010 and systematically reviewed the literature of cases with CPSS. We identified 316 published cases and 12 patients in our own clinic. Of the published cases (177 male), 185 had an extrahepatic and 131 an intrahepatic portosystemic shunt. Diagnosis was made at any age, from prenatal to late adulthood. Cardiac anomalies were found in 22% of patients. The main complications were hyperammonemia/neurological abnormalities (35%), liver tumors (26%), and pulmonary hypertension or hepatopulmonary syndrome (18%). The spectrum of neurological involvement ranged from changes in brain imaging, subtle abnormalities on neuropsychological testing, through learning disabilities to overt encephalopathy. Spontaneous shunt closure occurred mainly in infants with intrahepatic shunts. Therapeutic interventions included shunt closure by surgery or interventional radiology techniques (35%) and liver transplantation (10%) leading to an improvement of symptoms in the majority. These findings mirror the observations in our own patients. In this largest review of the reported clinical experience, we identify that children with CPSS may present with otherwise unexplained developmental delay, encephalopathy, pulmonary hypertension, hypoxemia, or liver tumors. When CPSS is diagnosed, children should be screened for all of these complications. Spontaneous closure of intrahepatic shunts may occur in infancy. Closure of the shunt is indicated in symptomatic patients and is associated with a favorable outcome.

Time-related patterns of ventricular shunt failure.

PubMed

Kast, J; Duong, D; Nowzari, F; Chadduck, W M; Schiff, S J

1994-11-01

Proximal obstruction is reported to be the most common cause of ventriculoperitoneal (VP) shunt failure, suggesting that imperfect ventricular catheter placement and inadequate valve mechanisms are major causes. This study retrospectively examined patterns of shunt failure in 128 consecutive patients with symptoms of shunt malfunction over a 2-year period. Factors analyzed included site of failure, time from shunt placement or last revision to failure, age of patient at time of failure, infections, and primary etiology of the hydrocephalus. One hundred of these patients required revisions; 14 revisions were due to infections. In this series there was a higher incidence of distal (43%) than of proximal (35%) failure. The difference was not statistically significant when the overall series was considered; however, when factoring time to failure as a variable, marked differences were noted regardless of the underlying cause of hydrocephalus or the age of the patient. Of the 49 patients needing a shunt revision or replacement within 2 years of the previous operation, 50% had proximal malfunction, 14% distal, and 10% had malfunctions attributable directly to the valve itself. Also, 12 of the 14 infections occurred during this time interval. In sharp contrast, of the 51 patients having shunt failure from 2 to more than 12 years after the previous procedure, 72% had distal malfunction, 21% proximal, and only 6% had a faulty valve or infection. This difference between time to failure for proximal versus distal failures was statistically significant (P < 0.00001 for both Student's t-test and non-parametric Mann-Whitney U-test).(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital intrahepatic portohepatic shunt managed by interventional radiologic occlusion: a case report and literature review.

PubMed

Grimaldi, Chiara; Monti, Lidia; Falappa, Piergiorgio; d'Ambrosio, Giuseppe; Manca, Antonio; de Ville de Goyet, Jean

2012-02-01

Congenital intrahepatic portosystemic shunts are rare hepatic vascular anomalies that often lead to severe secondary conditions. A 6-year-old boy was referred for assessment of severe hypoxia, and a large liver mass was diagnosed with such a malformation and was managed by direct closure of the venous fistula by interventional radiology. Follow-up assessment shows normalization of the respiratory condition and a progressive reduction of the vascular liver lesion. Review of literature suggests that radiologic interventions are currently the criterion standard for managing these conditions, with surgery reserved for patients who are not eligible for radiologic procedure and those requiring liver transplantation. Copyright © 2012 Elsevier Inc. All rights reserved.

Venous Shunt Versus Venous Ligation for Vascular Damage Control: The Immunohistochemical Evidence.

PubMed

Góes Junior, Adenauer Marinho de Oliveira; Abib, Simone de Campos Vieira; Alves, Maria Teresa de Seixas; Ferreira, Paulo Sérgio Venerando da Silva; Andrade, Mariseth Carvalho de

2017-05-01

To evaluate the expression of immunohistochemical markers of tissue ischemia (iNOS, eNOS, and HSP70) in a vascular damage control experimental model to determine if a venous temporary vascular shunt insertion leads to a better limb perfusion when compared with the ligature of the injured vein. Experimental study in male Sus Scrofa weighting 40 Kg. Animals were distributed into 5 groups: group 1 animals were submitted to right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2 animals were submitted to right EIA shunting and right EIV shunting; group 3 animals were submitted to right EIV ligation; group 4 animals were submitted to right EIV shunting; group 5 animals were not submitted to vascular shunting or venous ligation. Transonic Systems flowmeters were used to measure vascular flow on right and left external iliac vessels, and i-STAT (Abbot) portable blood analyzer was used for EIVs blood biochemical analysis. An initial baseline register of invasive arterial pressure, iliac vessels flow, and venous blood analysis was performed. Arterial pressure and iliac vessels flow were taken immediately after right iliac vessels shunting or ligation. Then, hemorrhagic shock was induced by continuous 20 mL/min blood withdraw from the external right jugular vein whereas arterial blood pressure and iliac vessels flow registers were taken every 10 min, and blood samples from EIVs were obtained every 30 min until the vascular flow through right EIA (or through the shunt inserted into the right EIV for group 4 animals) became inexistent or until the animal's death. After the end of the experiments, bilateral hind limb's biopsies were obtained for immunohistochemical analysis. Using image editing and analysis software, the expression of iNOS, eNOS, and HSP70 (3 well-known ischemic associated immunohistochemical markers) was assessed. The mean expression of each marker in the right hind limb was compared between groups. For statistical

Washout Ratio in the Hepatic Vein Measured by Contrast-Enhanced Ultrasonography to Distinguish Between Inflammatory and Noninflammatory Hepatic Disorders in Dogs.

PubMed

Morishita, K; Hiramoto, A; Michishita, A; Takagi, S; Osuga, T; Lim, S Y; Nakamura, K; Sasaki, N; Ohta, H; Takiguchi, M

2017-05-01

Perflubutane microbubbles, a second-generation ultrasound contrast agent, are phagocytized by Kupffer cells. This characteristic may be useful to differentiate diffuse hepatic diseases in dogs. To determine whether the washout ratio in the hepatic vein (HV) measured by contrast-enhanced ultrasonography (CEUS) can distinguish between inflammatory and noninflammatory hepatic disorders in dogs. Forty-one client-owned dogs with hepatic disorders including 14 with hepatitis, 7 with primary hypoplasia of the portal vein (PHPV), 9 with congenital portosystemic shunt (cPSS), and 11 with other hepatopathy were enrolled. Six dogs without hepatic disease also were evaluated as healthy controls. Dogs with hepatic disorders were prospectively included. Contrast-enhanced ultrasonography of the HV was performed for 2 minutes. Washout ratio was defined as the attenuation rate from peak intensity to the intensity at the end of the CEUS study. Washout ratio in the hepatitis group (median, 18.0%; range, 2.0-37.0%) was significantly lower than that of the PHPV (median, 52.2%; range, 11.5-86.3%), cPSS (median, 60.0%; range, 28.6-77.4%), other hepatopathy (median, 70.5%; range, 26.6-88.4%), and normal (median, 78.0%; range, 60.7-91.7%) groups. The area under the receiver operating characteristic curve for hepatitis was 0.960, with a 95% confidence interval (CI) of 0.853-0.990. Washout ratio ≤37.1% resulted in a sensitivity of 100% (95% CI, 78.5-100%) and specificity of 85.2% (95% CI, 67.5-94.1%) for the prediction of hepatitis. Washout ratio can distinguish hepatitis from the other noninflammatory disorders with high accuracy. This result might reflect impaired Kupffer cell phagocytosis in dogs with hepatitis. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Cross-Species Functionality of Pararetroviral Elements Driving Ribosome Shunting

PubMed Central

Pooggin, Mikhail M.; Fütterer, Johannes; Hohn, Thomas

2008-01-01

Background Cauliflower mosaic virus (CaMV) and Rice tungro bacilliform virus (RTBV) belong to distinct genera of pararetroviruses infecting dicot and monocot plants, respectively. In both viruses, polycistronic translation of pregenomic (pg) RNA is initiated by shunting ribosomes that bypass a large region of the pgRNA leader with several short (s)ORFs and a stable stem-loop structure. The shunt requires translation of a 5′-proximal sORF terminating near the stem. In CaMV, mutations knocking out this sORF nearly abolish shunting and virus viability. Methodology/Principal Findings Here we show that two distant regions of the CaMV leader that form a minimal shunt configuration comprising the sORF, a bottom part of the stem, and a shunt landing sequence can be replaced by heterologous sequences that form a structurally similar configuration in RTBV without any dramatic effect on shunt-mediated translation and CaMV infectivity. The CaMV-RTBV chimeric leader sequence was largely stable over five viral passages in turnip plants: a few alterations that did eventually occur in the virus progenies are indicative of fine tuning of the chimeric sequence during adaptation to a new host. Conclusions/Significance Our findings demonstrate cross-species functionality of pararetroviral cis-elements driving ribosome shunting and evolutionary conservation of the shunt mechanism. We are grateful to Matthias Müller and Sandra Pauli for technical assistance. This work was initiated at Friedrich Miescher Institute (Basel, Switzerland). We thank Prof. Thomas Boller for hosting the group at the Institute of Botany. PMID:18286203

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

PubMed

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

2016-11-01

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

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

PubMed

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

2018-01-16

Transjugular intrahepatic portosystemic shunt (TIPS) is an established method for portal hypertension. This study was to investigate the long-term safety, technical success, and patency of TIPS, and to determine the risk factors and clinical impacts of shunt dysfunction. A total of 154 consecutive patients undergoing embolotherapy of gastric coronary vein and/or short gastric vein and TIPS creation were prospectively studied. Follow-up data included technical success, patency and revision of TIPS, and overall survival of patients. During the study, the primary and secondary technical success rates were 98.7% and 100%, respectively. Sixty-three patients developed shunt dysfunction, 30 with shunt stenosis and 33 with shunt occlusion. The cumulative 60-month primary, primary assisted, and secondary patency rates were 19.6%, 43.0%, and 93.4%, respectively. The cumulative 60-month overall survival rates were similar between the TIPS dysfunction group and the TIPS non-dysfunction group (68.6% vs. 58.6%, P = .096). Baseline portal vein thrombosis (P < .001), use of bare stents (P = .018), and portal pressure gradient (PPG) (P = .020) were independent predictors for shunt dysfunction, hepatocellular carcinoma (P < .001), and ascites (P = .003) for overall survival. The accuracy of PPG for shunt dysfunction was statistically significant (P < .001), and a cutoff value of 8.5 had 77.8% sensitivity and 64.8% specificity. The long-term safety, technical success, and patency of TIPS were good; baseline portal vein thrombosis, use of bare stents, and PPG were significantly associated with shunt dysfunction; shunt dysfunction has little impact on patients' long-term survival because of high secondary patency rates. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

The spatial organization of intra-tumour heterogeneity and evolutionary trajectories of metastases in hepatocellular carcinoma

NASA Astrophysics Data System (ADS)

Zhai, Weiwei; Lim, Tony Kiat-Hon; Zhang, Tong; Phang, Su-Ting; Tiang, Zenia; Guan, Peiyong; Ng, Ming-Hwee; Lim, Jia Qi; Yao, Fei; Li, Zheng; Ng, Poh Yong; Yan, Jie; Goh, Brian K.; Chung, Alexander Yaw-Fui; Choo, Su-Pin; Khor, Chiea Chuen; Soon, Wendy Wei-Jia; Sung, Ken Wing-Kin; Foo, Roger Sik-Yin; Chow, Pierce Kah-Hoe

2017-02-01

Hepatocellular carcinoma (HCC) has one of the poorest survival rates among cancers. Using multi-regional sampling of nine resected HCC with different aetiologies, here we construct phylogenetic relationships of these sectors, showing diverse levels of genetic sharing, spanning early to late diversification. Unlike the variegated pattern found in colorectal cancers, a large proportion of HCC display a clear isolation-by-distance pattern where spatially closer sectors are genetically more similar. Two resected intra-hepatic metastases showed genetic divergence occurring before and after primary tumour diversification, respectively. Metastatic tumours had much higher variability than their primary tumours, suggesting that intra-hepatic metastasis is accompanied by rapid diversification at the distant location. The presence of co-existing mutations offers the possibility of drug repositioning for HCC treatment. Taken together, these insights into intra-tumour heterogeneity allow for a comprehensive understanding of the evolutionary trajectories of HCC and suggest novel avenues for personalized therapy.

Investigating PID shunting in polycrystalline silicon modules via multiscale, multitechnique characterization

DOE PAGES

Harvey, Steven P.; Moseley, John; Norman, Andrew; ...

2018-02-27

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

Autologous patch graft in tube shunt surgery.

PubMed

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

1999-10-01

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

The role of operative intervention in management of congenital extrahepatic portosystemic shunt.

PubMed

Sanada, Yukihiro; Urahashi, Taizen; Ihara, Yoshiyuki; Wakiya, Taiichi; Okada, Noriki; Yamada, Naoya; Egami, Satoshi; Hishikawa, Shuji; Kawano, Youichi; Ushijima, Kentaro; Otomo, Shinya; Sakamoto, Koichi; Nakata, Manabu; Yasuda, Yoshikazu; Mizuta, Koichi

2012-03-01

Congenital extrahepatic portosystemic shunt (CEPS) is a rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. It is still a matter of debate whether conservative or operative strategies should be used to treat symptomatic CEPS. The aim of this study was to evaluate the role of operative intervention in the management of CEPS. Between June 2004 and August 2010, 6 consecutive patients with symptomatic CEPS were treated in our department. There were 3 male and 3 female patients, with a median age of 3.5 years (range, 1-8). Their demographic, clinical, and laboratory data were analyzed. All patients were scheduled to undergo shunt ligation or liver transplantation (LT). Living donor LT was carried out in 4 patients, and shunt ligation in 2. After a median follow-up of 25 months, all the patients are alive currently with marked relief of symptoms. Shunt ligation or LT for symptomatic CEPS is potentially curative. Crown Copyright © 2012. Published by Mosby, Inc. All rights reserved.

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

PubMed

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

2013-01-01

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

Integration of Thermal Energy Harvesting in Semi-Active Piezoelectric Shunt-Damping Systems

NASA Astrophysics Data System (ADS)

Lubieniecki, Michał; Uhl, Tadeusz

2015-01-01

The opportunities to energize a broad range of devices by use of energy available almost anywhere and in many forms are almost unlimited. A major advantage of energy harvesting is the manufacture of small autonomous electronic devices with no need for power supply and maintenance. Shunt damping circuits, although unfavorably affected by the size and mass of bulky coil inductors, started to base on synthetic inductors losing their passivity. In this paper we report a study of the feasibility of powering shunt damping circuits by use of thermal energy otherwise irrevocably lost from a bearing. The heat generated in the bearing is converted thermoelectrically into electric energy which is then used to power synthetic inductance circuitry. We show that the power demand of such circuit can be satisfied by use of a thermoelectric generator paired with a moderately loaded bearing.

Complications of congenital portosystemic shunts in children: therapeutic options and outcomes.

PubMed

Franchi-Abella, Stéphanie; Branchereau, Sophie; Lambert, Virginie; Fabre, Monique; Steimberg, Clarisa; Losay, Jean; Riou, Jean-Yves; Pariente, Danièle; Gauthier, Frédéric; Jacquemin, Emmanuel; Bernard, Olivier

2010-09-01

Congenital portosystemic shunts are rare vascular malformations that lead to severe complications. Their management is controversial. The aim of this study was to propose a clear definition of the risks and management of congenital portosystemic shunts in children according to our experience and a review of the literature. Twenty-two children with a complicated congenital portosystemic shunt were studied in our institution. When necessary, management included portal pressure measurement and portal vein angiography during an occlusion test and closure of the shunt by surgical and/or endovascular methods. Five neonates with intrahepatic shunts presented with cholestasis that resolved spontaneously, and 17 older children presented with liver tumors (13) and/or hepatopulmonary syndrome (2), pulmonary artery hypertension (3), portosystemic encephalopathy (3), heart failure (1), and glomerulonephritis (1). The portosystemic shunt was extrahepatic (11) or intrahepatic (6). Portosystemic shunts were closed by endovascular methods in 5 children and surgically in 10, 4 of whom had portal pressure during occlusion above 35 mmHg and extremely hypoplastic or undetectable portal veins requiring banding of the fistula before closure. Shunt closure resulted in restoration of intrahepatic portal flow in all, with complete or partial regression of benign liver masses, and regression or stabilization of pulmonary, cardiac, neurological, and renal complications. Congenital portosystemic shunt carries risks of severe complications in children. Closure of a shunt persisting after age 2 years should be considered preventively. Intrahepatic portal flux restoration can be expected, even when intrahepatic portal veins are extremely hypoplastic or undetectable.

Programmable shunts and headphones: Are they safe together?

PubMed

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

2015-10-01

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

Postcorrective surgery improvement of nocturnal hypoxemia in a case of partial anomalous pulmonary venous connection and aberrant hepatic vein drainage.

PubMed

Agrawal, Abhinav; Palkar, Atul V; Sahni, Sonu; Vatsia, Sheel K; Shah, Rakesh D; Talwar, Arunabh

2016-01-01

Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital anomaly that leads to an anatomical left-to-right shunt. Termination of the intrahepatic inferior vena cava (IVC) with its azygos continuation associated with the hepatic venous connection to the left atrium (LA) is also a rare congenital anomaly that results in an anatomical right-to-left shunt. A 65-year-old male presented with severe dyspnea on exertion and pedal edema. He was further diagnosed at our clinic and was found to have both the aforementioned congenital abnormalities, creating a bidirectional shunt. On further investigation, he was found to have nocturnal hypoxemia on overnight oximetry. The patient was successfully treated via surgical corrections of the congenital anomalies leading to symptomatic improvement as well as the resolution of nocturnal hypoxemia.

Temporary arterial shunts to maintain limb perfusion after arterial injury: an animal study

NASA Technical Reports Server (NTRS)

Dawson, D. L.; Putnam, A. T.; Light, J. T.; Ihnat, D. M.; Kissinger, D. P.; Rasmussen, T. E.; Bradley, D. V. Jr

1999-01-01

BACKGROUND: Temporary shunt placement can quickly restore perfusion after extremity arterial injury. This study examined the adequacy of limb blood flow with shunt use, non-heparin-bonded shunt patency over prolonged periods, and the safety of this technique. METHODS: Common iliac arteries were divided and 4.0-mm Silastic Sundt shunts placed in 16 anesthetized pigs. Eight (group I) had shunts placed immediately; eight others (group II) were shunted after an hour of limb ischemia and hemorrhagic shock. Physiologic parameters and femoral artery blood flow in both hindlimbs were continuously monitored. Limb lactic acid generation, oxygen utilization, and hematologic and metabolic effects were serially evaluated for 24 hours. RESULTS: Shunts remained patent in 13 of 16 pigs. Shunts thrombosed in two group I animals because of technical errors, but functioned well after thrombectomy and repositioning. Patency could not be maintained in one animal that died from shock. Flow in group I shunted limbs was 57 (+/-11 SD) % of control. For group II animals in shock, shunted limb flow initially averaged 46 +/- 15% of control, but 4 hours after shunt placement, the mean limb blood flow was the same as in group I. Increased oxygen extraction compensated for the lower flow. Lactic acid production was not increased in comparison to control limbs. CONCLUSION: Shunts provided adequate flow in this model of extremity trauma. Correctly placed shunts stayed patent for 24 hours, without anticoagulation, if shunt placement followed resuscitation.

A prospective study of basal insulin concentrations in dogs with congenital portosystemic shunts.

PubMed

Collings, A J; Gow, A G; Marques, A; Yool, D; Furneaux, R; Mellanby, R; Watson, P J

2012-04-01

Hypoglycaemia is a common cause of morbidity in dogs with congenital portosystemic shunts but the aetiology is unknown. The hypothesis of this study was that dogs with congenital portosystemic shunts would have significantly higher insulin concentrations than dogs without congenital portosystemic shunts. The main objective of the study was to compare peripheral glucose and insulin concentrations between dogs with congenital portosystemic shunts and dogs without congenital portosystemic shunts. Peripheral serum insulin and plasma glucose concentrations were measured in dogs with congenital portosystemic shunts and without congenital portosystemic shunts and compared both between groups as well as to reference intervals derived from healthy dogs. Congenital portosystemic shunts were diagnosed in 41 dogs. Forty-eight dogs hospitalised with other conditions acted as controls. Serum insulin concentrations were mildly elevated (Ä40 μU/mL) in seven dogs and were markedly elevated in two dogs with congenital portosystemic shunts, yet mild hypoglycaemia (3·3 mmol/L) was detected in only one of these dogs. Four dogs with congenital portosystemic shunts showed fasting hypoglycaemia, yet insulin concentrations were within or below the reference interval in three. There was no difference between the median insulin concentration of dogs with congenital portosystemic shunts and without congenital portosystemic shunts. Hyperinsulinaemia is infrequently observed in dogs with congenital portosystemic shunts. The aetiology of hypoglycaemia in dogs with congenital portosystemic shunts merits further investigation. © 2012 British Small Animal Veterinary Association.

Porto Alegre as a Counter-Hegemonic "Global City": Building Globalization from below in Governance and Education

ERIC Educational Resources Information Center

Gandin, Luis Armando

2011-01-01

This paper analyzes the case of Porto Alegre, Brazil as a counter-hegemonic global city. Porto Alegre is a city with no particular relevance to neoliberal globalization that, nevertheless, was launched to a global scale by transformations in local governance. New mechanisms of deliberative democracy captured the attention of social actors…

Hepatitis C virus genotypes in Southern Brazil.

PubMed

Krug, L P; Lunge, V R; Ikuta, N; Fonseca, A S; Cheinquer, H; Ozaki, L S; Barros, S G

1996-12-01

The prevalence of hepatitis C virus (HCV) genotypes in Southern Brazil was studied in the plasma of 100 HCV-RNA-positive patients attended in Porto Alegre, South of Brazil. Reverse transcription-polymerase chain reaction (RT-PCR) products from the 5' noncoding region were double digested with RsaI-HaeIII and BstNI-HinfI and analyzed by restriction fragment length polymorphism (RFLP). Three genotypes (1, 2 and 3) were demonstrable, the most prevalent being HCV type 1 (55 of 100 patients, 55%), followed by HCV type 3 (37 of 100 patients, 37%) and HCV type 2 (8 of 100 patients, 8%). There was an unusual high prevalence of genotype 3, in contrast to the majority of published data from the Southeast region.

Identification, antimicrobial resistance and genotypic characterization of Enterococcus spp. isolated in Porto Alegre, Brazil

PubMed Central

Bender, Eduardo André; de Freitas, Ana Lúcia Peixoto; Reiter, Keli Cristine; Lutz, Larissa; Barth, Afonso Luís

2009-01-01

In the past two decades the members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. In the present study, we evaluated the antimicrobial resistance and genotypic characteristics of 203 Enterococcus spp. recovered from different clinical sources from two hospitals in Porto Alegre, Rio Grande do Sul, Brazil. The species were identified by conventional biochemical tests and by an automated system. The genetic diversity of E. faecalis presenting high-level aminoglycoside resistance (HLAR) was assessed by pulsed-field gel electrophoresis of chromosomal DNA after SmaI digestion. The E. faecalis was the most frequent specie (93.6%), followed by E. faecium (4.4%). The antimicrobial resistance profile was: 2.5% to ampicillin, 0.5% to vancomycin, 0.5% teicoplanin, 33% to chloramphenicol, 2% to nitrofurantoin, 66.1% to erythromycin, 66.5% to tetracycline, 24.6% to rifampicin, 30% to ciprofloxacin and 87.2% to quinupristin-dalfopristin. A total of 10.3% of the isolates proved to be HLAR to both gentamicin and streptomycin (HLR-ST/GE), with 23.6% resistant only to gentamicin (HLR-GE) and 37.4% only to streptomycin (HLR-ST). One predominant clonal group was found among E. faecalis HLR-GE/ST. The prevalence of resistance among beta-lactam antibiotics and glycopeptides was very low. However, in this study there was an increased number of HLR Enterococcus which may be spreading intra and inter-hospital. PMID:24031416

Predisposing Factors for Spontaneous Closure of Congenital Portosystemic Shunts.

PubMed

Paganelli, Massimiliano; Lipsich, José E; Sciveres, Marco; Alvarez, Fernando

2015-10-01

In a review of 382 cases of congenital portosystemic shunt, we found that presentation with neonatal cholestasis strongly predicts spontaneous closure of intrahepatic shunts (OR 8.3, 95% CI 3.4-20.2). Spontaneous closure before the 24th month of age is more likely for distal or multiple shunts, but rare for patent ductus venosus. Copyright © 2015 Elsevier Inc. All rights reserved.

Superconducting FCL using a combined inducted magnetic field trigger and shunt coil

DOEpatents

Tekletsadik, Kasegn D.

2007-10-16

A single trigger/shunt coil is utilized for combined induced magnetic field triggering and shunt impedance. The single coil connected in parallel with the high temperature superconducting element, is designed to generate a circulating current in the parallel circuit during normal operation to aid triggering the high temperature superconducting element to quench in the event of a fault. The circulating current is generated by an induced voltage in the coil, when the system current flows through the high temperature superconducting element.

Validation of the Hong Kong Liver Cancer Staging System in Determining Prognosis of the North American Patients Following Intra-arterial Therapy

PubMed Central

Sohn, Jae Ho; Duran, Rafael; Zhao, Yan; Fleckenstein, Florian; Chapiro, Julius; Sahu, Sonia P.; Schernthaner, Rüdiger E.; Qian, Tianchen; Lee, Howard; Zhao, Li; Hamilton, James; Frangakis, Constantine; Lin, MingDe; Salem, Riad; Geschwind, Jean-Francois

2018-01-01

Background & Aims There is debate over the best way to stage hepatocellular carcinoma (HCC). We attempted to validate the prognostic and clinical utility of the recently developed Hong Kong Liver Cancer (HKLC) staging system, a hepatitis B-based model, and compared data with that from the Barcelona Clinic Liver Cancer (BCLC) staging system in a North American population who underwent intra-arterial therapy (IAT). Methods We performed a retrospective analysis of data from 1009 patients with HCC who underwent intra-arterial therapy from 2000 through 2014. Most patients had hepatitis C or unresectable tumors; all patients underwent IAT, with or without resection, transplantation, and/or systemic chemotherapy. We calculated HCC stage for each patient using 5-stage HKLC (HKLC-5) and 9-stage HKLC (HKLC-9) system classifications, as well as the BCLC system. Survival information was collected up until end of 2014 at which point living or unconfirmed patients were censored. We compared performance of the BCLC, HKLC-5, and HKLC-9 systems in predicting patient outcomes using Kaplan-Meier estimates, calibration plots, c-statistic, Akaike information criterion, and the likelihood ratio test. Results Median overall survival time, calculated from first IAT until date of death or censorship, for the entire cohort (all stages) was 9.8 months. The BCLC and HKLC staging systems predicted patient survival times with significance (P<.001). HKLC-5 and HKLC-9 each demonstrated good calibration. The HKLC-5 system outperformed the BCLC system in predicting patient survival times (HKLC c=0.71, Akaike information criterion=6242; BCLC c=0.64, Akaike information criterion=6320), reducing error in predicting survival time (HKLC reduced error by 14%, BCLC reduced error by 12%), and homogeneity (HKLC χ2=201; P<.001; BCLC χ2=119; P<.001) and monotonicity (HKLC linear trend χ2=193; P<.001; BCLC linear trend χ2=111; P<.001). Small proportions of patients with HCC of stages IV or V, according to

The spatial organization of intra-tumour heterogeneity and evolutionary trajectories of metastases in hepatocellular carcinoma

PubMed Central

Zhai, Weiwei; Lim, Tony Kiat-Hon; Zhang, Tong; Phang, Su-Ting; Tiang, Zenia; Guan, Peiyong; Ng, Ming-Hwee; Lim, Jia Qi; Yao, Fei; Li, Zheng; Ng, Poh Yong; Yan, Jie; Goh, Brian K.; Chung, Alexander Yaw-Fui; Choo, Su-Pin; Khor, Chiea Chuen; Soon, Wendy Wei-Jia; Sung, Ken Wing-Kin; Foo, Roger Sik-Yin; Chow, Pierce Kah-Hoe

2017-01-01

Hepatocellular carcinoma (HCC) has one of the poorest survival rates among cancers. Using multi-regional sampling of nine resected HCC with different aetiologies, here we construct phylogenetic relationships of these sectors, showing diverse levels of genetic sharing, spanning early to late diversification. Unlike the variegated pattern found in colorectal cancers, a large proportion of HCC display a clear isolation-by-distance pattern where spatially closer sectors are genetically more similar. Two resected intra-hepatic metastases showed genetic divergence occurring before and after primary tumour diversification, respectively. Metastatic tumours had much higher variability than their primary tumours, suggesting that intra-hepatic metastasis is accompanied by rapid diversification at the distant location. The presence of co-existing mutations offers the possibility of drug repositioning for HCC treatment. Taken together, these insights into intra-tumour heterogeneity allow for a comprehensive understanding of the evolutionary trajectories of HCC and suggest novel avenues for personalized therapy. PMID:28240289

Prediction of Susceptibility to Acute Mountain Sickness Using Hypoxia-Induced Intrapulmonary Arteriovenous Shunt and Intracardiac Shunt Fractions

DTIC Science & Technology

2012-10-31

intrapulmonary and intracardiac shunt using saline contrast echocardiography to determine bubble/shunt scores. We will also use nuclear medicine imaging to...subjects have completed saline contrast echocardiography while breathing hypoxic gas mixtures. For Task #2 “10 hr hypoxic exposure and AMS... echocardiography while breathing an FIO2=0.14, will be susceptible or resistant to developing AMS after 10 hr hypoxic exposure. For Task #3 “Hypoxia

Decreased head circumference in shunt-treated compared with healthy children.

PubMed

Nilsson, Daniel; Svensson, Johanna; Korkmaz, Betül A; Nelvig, Helena; Tisell, Magnus

2013-11-01

In this study, the authors' goal was to compare head circumference in hydrocephalic children during the first 4 years of ventriculoperitoneal (VP) shunt treatment with data on healthy children and to investigate predictors of skull growth in children with a VP shunt. Children from western Sweden treated for hydrocephalus with an initial VP shunt insertion performed between 2001 and 2006 who were younger than 12 months of age at the time of surgery were included. Children with major brain malformations, craniofacial syndromes, large cysts, and tumors were excluded. Head circumference, weight, and height at 9 defined ages up to 4 years were obtained and compared with data from a reference population of 3650 healthy children using the standard deviation score (SDS). Predictors (length, weight, etiology of hydrocephalus, valve type, number of revisions, valve setting, number of adjustments, and time of first surgery) for head circumference SDS and changes in head circumference SDS from shunt insertion at 1 year to last measurement were analyzed using bivariate and multiple linear regression analysis. Fifty children were included. The mean SDSs for head circumference in shunt-treated compared with healthy children were 1.95 ± 2.50 at shunt insertion (p < 0.001, n = 44), 0.38 ± 1.97 at 1 year (p = 0.27, n = 33), -0.96 ± 2.05 at 2 years (p = 0.046, n = 21), -1.39 ± 2.25 at 3 years (p = 0.026, n = 16), and 0.63 ± 3.34 at 4 years (p = 0.73, n = 4). Significant predictors for low head circumference SDS at 1 year of age were low weight (p = 0.002) and short height (p = 0.022) and at last measurement low weight (p < 0.0001), short height (p = 0.002), and 1-4 shunt revisions (p = 0.034). A significant predictor for change in head circumference SDS from shunt insertion to 1 year of age was the number of shunt valve revisions (p = 0.04) and at last measurement an etiology of intraventricular hemorrhage (p = 0.0058). Shunt-treated children have smaller head circumferences at

Energy relaxation mechanisms in capacitively shunted flux qubits

NASA Astrophysics Data System (ADS)

Corcoles, Antonio; Rozen, Jim; Rothwell, Mary Beth; Keefe, George; di Vincenzo, David; Ketchen, Mark; Chow, Jerry; Rigetti, Chad; Rohrs, Jack; Borstelmann, Mark; Steffen, Matthias; IBM Quantum Computing Group Team

2011-03-01

Energy losses in superconducting qubits remain a major object of study in the road towards scalable, highly coherent qubit devices. The current understanding of the loss mechanisms in these devices is far from being complete and it is sometimes difficult to experimentally separate the different contributions to decoherence. Here we compare a traditional three Josephson-junction flux qubit to the recently implemented capacitively shunted flux qubit, whose energy decay is thought to be limited by dielectric losses arising from native oxides in the shunting capacitor. Keeping all parameters identical except for the shunting capacitance, we obtain energy relaxation times that are comparable for both types of qubit. This suggests that the energy relaxation time is not limited by junction losses in capacitively shunted flux qubits. We discuss some other possible loss mechanisms present in these devices.

Transient right-to-left shunt in massive pulmonary embolism.

PubMed

Panoutsopoulos, G; Ilias, L; Christakopoulou, I

2000-06-01

A 56-yr-old man, two months after an operation for an acoustic neurinoma, gradually developed dyspnea. Massive pulmonary embolism (MPE), with a significant right-to-left (R-L) shunt, was seen in a perfusion scan of the lungs with Tc-99m MAA. Radioactivity was noted in the thyroid, spleen, kidneys and brain. A cardiac ultrasound study did not reveal intracardiac shunting. A few days later, when the patient's condition improved, another perfusion scan of the lungs did not show the shunt, whereas a subsequent digital subtraction angiographic study confirmed the diagnosis of MPE but failed to reveal the cause of the shunt. In the absence of any possible pathophysiological mechanism, to explain the observed R-L shunt, we deduce that the particles of Tc-99m MAA might have passed through the precapillary pulmonary arteriovenous anastomoses and/or through dilated pulmonary capillaries, as a result of highly increased pulmonary vascular pressure due to MPE.

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

PubMed Central

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

2013-01-01

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

Plasma lactate concentrations and blood gas values in dogs undergoing surgical attenuation of a single congenital portosystemic shunt.

PubMed

Cariou, M P; Lipscomb, V J; Hughes, D; Brodbelt, D; Brockman, D J

2009-08-22

Plasma concentration of lactate and the values of pH, pO(2) and pCO(2) were measured in the portal, systemic venous and, when possible, systemic arterial blood of 31 dogs with a single congenital portosystemic shunt, before and shortly after the temporary complete occlusion of the shunt, and at the end of surgery. At completion of the surgery, the shunt in 16 of the dogs had been occluded completely whereas in the other 15 it had been occluded only partially. There were no significant differences between any of the measurements of these variables in the portal venous, systemic venous or arterial plasma of any of the dogs, or between the values measured in the groups in which the shunts had been occluded completely or partially. Furthermore, there were no significant differences between the two groups of dogs in the arteriovenous gradients calculated at any of the sampling sites or sampling times. None of the variables was associated with the development of postoperative complications.

Simultaneous Umbilical Hernia Repair with Transumbilical Ventriculoperitoneal Shunt Placement.

PubMed

Montalbano, Michael J; Loukas, Marios; Oakes, W Jerry; Tubbs, R Shane

2017-01-01

Recently, placement of a ventriculoperitoneal shunt via a transumbilical approach has been reported. Herein, we report the repair of an umbilical hernia via the same incision and introduction of the distal end of a ventricultoperitoneal shunt into the peritoneal cavity in 3 patients. A case illustration is included. Both hernia repair and placement of the distal end of the ventriculoperitoneal shunt were uncomplicated in our small case series. To our knowledge, simultaneous repair of an umbilical hernia followed by transumbilical shunt placement has not been reported. As umbilical hernias are so common in infants, this finding, based on our experience, should not exclude placement of peritoneal tubing in the same setting. © 2017 S. Karger AG, Basel.

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

PubMed

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.

Evaluation of Mismatch Losses due to Shunts in industrial Silicon Photovoltaic Modules

NASA Astrophysics Data System (ADS)

Somasundaran, P.; Shilpi, M.; Gupta, R.

2017-05-01

In order to achieve higher efficiencies in photovoltaic module technology, it is important to characterize the shunts and other defects which degrade the performance of cells and modules as well as decrease their efficiency. These shunts also affect the reliability of cells and modules. It is important to understand how much fill factor and power loss is caused by the presence of shunts in the module. Shunts not only reduce the module power output, but also affect the I-V characteristics of the cell and hence the characteristics of the shunted cells are different from those of the shunt-free cells connected in the module leading to the mismatch effect. This is an interesting effect which has been systematically investigated in the present work. Moreover, the flow of increased shunt current will give rise to increased temperature in the region of shunt, which will affect the cell and hence module performance. In the present study, the distributed diode model has been extended to the module level and applied to evaluate the electrical mismatch losses and thermal mismatch losses due to shunts in industrial Silicon PV modules.

Management of Hepatic Encephalopathy in the Hospital

PubMed Central

Leise, Michael D.; Poterucha, John J.; Kamath, Patrick S.; Kim, W. Ray

2014-01-01

Hepatic encephalopathy (HE) develops in about 50% of patients with cirrhosis and is one of the features of decompensated cirrhosis. The inpatient incidence of HE is approximately 23,000/year and management of these patients is common for internists and subspecialists. Treatment of the hospitalized patient with HE has changed in recent years. Treatment entails two phases, induction and maintenance of remission. Most cases of significant hepatic encephalopathy are precipitated by infection, gastrointestinal bleeding, medications or other culprits. All patients should be evaluated for secondary triggers of HE and treatment should be initiated with a non-absorbable disaccharide (i.e. lactulose) in most cases. Rifaximin (off-label) can be added in patients not responding to lactulose. Neomycin is a less preferable alternative to rifaximin, due to its side effect profile. Other therapies including zinc, LOLA, and branch chain amino acids can be considered for patients not responding to a disaccharide and non-absorbable antibiotic. Large portosystemic shunts may be embolized in patients with medically refractory recurrent or severe HE with otherwise well compensated cirrhosis. Molecular Adsorbent Recirculating System is now available for patients with severe hepatic encephalopathy who do not respond to medical therapy. It is critically important that patients hospitalized with significant hepatic encephalopathy continue a maintenance medication(s) at the time of dismissal to prevent further episodes. Patients with a 1st time episode of HE can be placed on lactulose and careful instruction should be provided to patient and caregiver about titration of dose to achieve 3 bowel movements per day. Patients with recurrent HE episodes despite lactulose benefit from the addition of rifaximin which decreases the frequency of recurrent HE episodes and related hospitalizations. Lastly, patients and their families should be counselled about the risk of motor vehicle accidents which

Change in hepatic function, hemodynamics, and morphology after liver transplant. Physiological effect of therapy.

PubMed

Millikan, W J; Henderson, J M; Stewart, M T; Warren, W D; Marsh, J W; Galloway, J R; Jennings, H; Kawasaki, S; Dodson, T F; Perlino, C A

1989-05-01

Orthotopic liver transplantation (OLT) has become standard therapy for patients with acute hepatic necrosis and end-stage liver disease. This study measured change in hepatic function (galactose elimination capacity [GEC]), liver blood flow (low dose galactose clearance: flow), hepatic volume (CT scan; volume) and morphology after OLT. The aim was to measure the physiologic response after OLT and compare this response with that after selective shunt (SS) and sclerotherapy (ES) to determine which patients should receive specific therapy. Between January 1987 and November 1988, 37 patients underwent OLT. Operative mortality was 18%, which was similar to that of SS in Child's C cirrhotics. GEC and volume were less in transplant patients than in cirrhotics treated with SS or ES. GEC, flow, and volume normalized after OLT; GEC was preserved after ES and SS, but volume decreased. Three preoperative patterns were observed that can aid in selection of OLT candidates. Patients with chronic cirrhosis (chronic active hepatitis; cryptogenic) need OLT when GEC is less than or equal to 225 mg/min and volume is less than or equal to 50% normal. Patients with Budd-Chiari Syndrome require OLT if cirrhosis has evolved. Patients with sclerosing cholangitis and primary biliary cirrhosis qualify for transplants when complications of the portal hypertensive syndrome develop. The studies can also direct therapy for ES failures. Selective shunt is indicated in those patients with stable disease whose GEC is greater than or equal to 300 mg/min and liver volume is greater than 75% normal; OLT is indicated for cirrhotics with GEC that is less than 225 mg/min and liver volume that is less than 50% predicted normal.

Congenital portosystemic shunts: imaging findings and clinical presentations in 11 patients.

PubMed

Konstas, Angelos A; Digumarthy, Subba R; Avery, Laura L; Wallace, Karen L; Lisovsky, Mikhail; Misdraji, Joseph; Hahn, Peter F

2011-11-01

To evaluate the clinical anatomy and presentations of congenital portosystemic shunts, and determine features that promote recognition on imaging. Institutional review board approval was obtained for this HIPAA-compliant study. The requirement for written informed consent was waived. Radiology reports were retrospectively reviewed from non-cirrhotic patients who underwent imaging studies from January 1999 through February 2009. Clinical sources reviewed included electronic medical records, archived images and histopathological material. Eleven patients with congenital portosystemic shunts were identified (six male and five female; age range 20 days to 84 years). Seven patients had extrahepatic and four patients had intrahepatic shunts. All 11 patients had absent or hypoplastic intrahepatic portal veins, a feature detected by CT and MRI, but not by US. Seven patients presented with shunt complications and four with presentations unrelated to shunt pathophysiology. Three adult patients had four splenic artery aneurysms. Prospective radiological evaluation of five adult patients with cross-sectional imaging had failed prospectively to recognize the presence of congenital portosystemic shunts on one or more imaging examinations. Congenital portosystemic shunts are associated with splenic artery aneurysms, a previously unrecognized association. Portosystemic shunts were undetected during prospective radiologic evaluation in the majority of adult patients, highlighting the need to alert radiologists to this congenital anomaly. Copyright © 2010. Published by Elsevier Ireland Ltd.

Single-Session Percutaneous Endovascular Mesocaval Shunt Creation and Balloon-Occluded Retrograde Transvenous Obliteration for the Treatment of Gastric Varices.

PubMed

Srinivasa, Ravi Nara; Majdalany, Bill S; Chick, Jeffrey Forris Beecham; Meadows, J Matthew; Fenlon, Jordan Bruce; Brewerton, Charles; Saad, Wael E

2018-01-01

In the setting of portal hypertension, the body responds by creating portosystemic venous shunts, which may lead to the development of varices. Endoscopic treatment of these varices is often warranted to prevent catastrophic bleeding. During the course of variceal treatment, 1 or more portosystemic shunts may be sacrificed, which may acutely exacerbate portal hypertension and reduce systemic venous return. This report describes percutaneous creation of a mesocaval shunt and balloon-occluded retrograde transvenous obliteration (BRTO) in a patient with cavernous transformation of the portal vein. The patient had previously undergone an unsuccessful attempt at transjugular intrahepatic portosystemic shunt (TIPS) creation with postoperative bleeding requiring splenectomy. As TIPS was not feasible, creation of a percutaneous mesocaval shunt provided an alternate pathway for portosystemic decompression, facilitating safe treatment of gastric varices with BRTO via a gastrorenal shunt. These procedures were performed simultaneously to reduce the risk of variceal bleeding from acute changes in portal venous pressures and redirect blood flow through the shunt to maintain patency. This is the first reported case of combined mesocaval shunt placement and BRTO in a single session. Copyright © 2017 Elsevier Inc. All rights reserved.

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

PubMed

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

2009-12-01

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

Effects of equivalent series resistance on the noise mitigation performance of piezoelectric shunt damping

NASA Astrophysics Data System (ADS)

Lai, Szu Cheng; Sharifzadeh Mirshekarloo, Meysam; Yao, Kui

2017-05-01

Piezoelectric shunt damping (PSD) utilizes an electrically-shunted piezoelectric damper attached on a panel structure to suppress the transmission of acoustic noise. The paper develops an understanding on the effects of equivalent series resistance (ESR) of the piezoelectric damper in a PSD system on noise mitigation performance, and demonstrates that an increased ESR leads to a significant rise in the noise transmissibility due to reduction in the system’s mechanical damping. It is further demonstrated with experimental results that ESR effects can be compensated in the shunt circuit to significantly improve the noise mitigation performance. A theoretical electrical equivalent model of the PSD incorporating the ESR is established for quantitative analysis of ESR effects on noise mitigation.

Resident-performed Ex-PRESS shunt implantation versus trabeculectomy.

PubMed

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

2012-09-01

To compare outcomes between resident-performed trabeculectomy and Ex-PRESS shunt implantation. A consecutive cohort of 36 Ex-PRESS shunt implantations and 57 trabeculectomies (1 eye/patient) performed by resident surgeons in their third year of ophthalmic training at the University of California, San Francisco and at the San Francisco Veterans Administration Hospital, under the supervision of a single glaucoma fellowship-trained surgeon were included in this study. Eyes with < 6 months of follow-up or previous glaucoma surgery were excluded. Preoperative and postoperative intraocular pressure (IOP), preoperative and postoperative number of ocular antihypertensive medications and complication rates were compared between the 2 procedures retrospectively. No difference was found in postoperative IOP (all, P≥0.099) or proportional decrease in IOP (all, P≥0.092) between the trabeculectomy and Ex-PRESS shunt groups at all follow-up points. On average, the Ex-PRESS shunt group required significantly less ocular antihypertensive medication to control IOP at 3 months postoperative (P=0.01), but no difference was found at 6 months or 1 year (all, P≥0.28). A larger proportion of Ex-PRESS shunt patients had good IOP control without medication at 3 (P=0.057) and 6 months (P=0.076) postoperatively. No difference was found in the rates of sight-threatening complications between groups (all, P≥0.22). In the hands of ophthalmology residents in their third year of training, the trabeculectomy and Ex-PRESS shunt implantation procedures perform comparably in terms of postoperative IOP control, reduction in patient dependence on ocular antihypertensive medications, and risk of complication in our population.

Aqueous shunts in glaucoma: a report by the American Academy of Ophthalmology.

PubMed

Minckler, Don S; Francis, Brian A; Hodapp, Elizabeth A; Jampel, Henry D; Lin, Shan C; Samples, John R; Smith, Scott D; Singh, Kuldev

2008-06-01

To provide an evidence-based summary of commercially available aqueous shunts currently used in substantial numbers (Ahmed [New World Medical, Inc., Rancho Cucamonga, CA], Baerveldt [Advanced Medical Optics, Inc., Santa Ana, CA], Krupin [Eagle Vision, Inc, Memphis, TN], Molteno [Molteno Ophthalmic Ltd., Dunedin, New Zealand]) to control intraocular pressure (IOP) in various glaucomas. Seventeen previously published randomized trials, 1 prospective nonrandomized comparative trial, 1 retrospective case-control study, 2 comprehensive literature reviews, and published English language, noncomparative case series and case reports were reviewed and graded for methodologic quality. Aqueous shunts are used primarily after failure of medical, laser, and conventional filtering surgery to treat glaucoma and have been successful in controlling IOP in a variety of glaucomas. The principal long-term complication of anterior chamber tubes is corneal endothelial failure. The most shunt-specific delayed complication is erosion of the tube through overlying conjunctiva. There is a low incidence of this occurring with all shunts currently available, and it occurs most frequently within a few millimeters of the corneoscleral junction after anterior chamber insertion. Erosion of the equatorial plate through the conjunctival surface occurs less frequently. Clinical failure of the various devices over time occurs at a rate of approximately 10% per year, which is approximately the same as the failure rate for trabeculectomy. Based on level I evidence, aqueous shunts seem to have benefits (IOP control, duration of benefit) comparable with those of trabeculectomy in the management of complex glaucomas (phakic or pseudophakic eyes after prior failed trabeculectomies). Level I evidence indicates that there are no advantages to the adjunctive use of antifibrotic agents or systemic corticosteroids with currently available shunts. Too few high-quality direct comparisons of various available

Impact of Serum Vancomycin Trough Levels in the Treatment of Central Nervous System Shunt Infections Caused by Coagulase-Negative Staphylococci.

PubMed

Gibson, Ashley; Kaplan, Sheldon L; Vallejo, Jesus G

2018-04-26

Coagulase-negative staphylococci (CoNS) are a common cause of pediatric ventricular shunt infections. The Infectious Diseases Society of America recommends vancomycin serum troughs of 15-20 µg/mL when treating CoNS shunt infections in adult patients. We report a series of pediatric cases of CoNS shunt infections in which clinical cure was obtained with troughs < 15 µg/mL. These findings question the relevance of this recommendation in pediatric patients. © 2018 S. Karger AG, Basel.

Successful preemptive surgical division of type 2-congenital extrahepatic portosystemic shunt in children.

PubMed

Nii, Akira; Takehara, Hiro-o; Kuyama, Hisako; Shimada, Mitsuo

2009-02-01

A congenital extrahepatic portosystemic shunt (CEPS) is a rare abnormality. The shunts are classified into 2 types. Of these, a type 2-shunt is a side-to-side one, which may be treated by a simple shunt division. The aim of this retrospective study was to clarify the effects of a surgical shunt division on 4 children with type 2-CEPS. Between June 2002 and June 2008, 4 children with type 2-CEPS underwent a surgical shunt division. Various clinical factors of each patient, including shunt types, shut ratios evaluated by portal scintigraphy using (123)I-iodoamphetamine, serum levels of ammonia and total bile acids before and after surgery were evaluated. Two children had a conventional open surgery and the other two had a laparoscopic surgery. The serum levels of ammonia as well as total bile acids of these children decreased significantly to the normal levels within a month after the surgical shunt divisions. All the children had a better clinical course. A shunt division, especially by laparoscopic surgery, is an effective therapy for type 2-CEPS. To the best of our knowledge by reviewing literatures, our cases are the youngest ones treated by laparoscopic shunt division.

Endoscopic Ultrasound-Guided Vascular Therapy: The Present and the Future

PubMed Central

Hall, Philip S.J.; Teshima, Christopher; May, Gary R.; Mosko, Jeffrey D.

2017-01-01

Endoscopic ultrasound (EUS) offers access to many intra-abdominal vessels that until now have only been accessible to the surgeon and interventional radiologist. In addition to assisting with diagnostics, this unique access offers the potential for therapeutic intervention for a host of indications. To date, this has had the most clinical impact in the treatment of gastroesophageal varices, with EUS-guided coil and glue application growing in use worldwide. Although randomised controlled trial data is lacking, we discuss the growing body of literature behind EUS-guided therapy in the management of varices. EUS has also been used in specialized centres to assist in non-variceal gastrointestinal bleeding. The treatment of bleeding from Dieulafoy lesions, tumours and pancreatic pseudoaneurysms has all been described. The potential applications of EUS have also extended to the placement of portal vein stents and porto-systemic shunts in animal models. As medicine continues to move to increasingly less invasive interventions, EUS-guided therapies offer substantial promise for the safe and effective delivery of targeted treatment for a widening array of vascular disorders. PMID:28391673

Clinical and economic consequences of antibiotic-impregnated cerebrospinal fluid shunt catheters.

PubMed

Eymann, Regina; Chehab, Somar; Strowitzki, Martin; Steudel, Wolf-Ingo; Kiefer, Michael

2008-06-01

The authors evaluated the safety and efficacy of antibiotic-impregnated shunt catheters (AISCs) and determined the cost-benefit ratio related to the fact that AISCs increase the implant costs of a shunt procedure by approximately $400 per patient. The control group comprised 98 adults with chronic hydrocephalus and 22 children, who were treated without AISCs (non-AISCs). In the treatment group, AISCs (Bactiseal, Codman, Johnson & Johnson) were implanted in 171 adults and 26 children. The minimum follow-up period was 6 months. Important risk factors for shunt infections (such as age, comorbidity, cause of hydrocephalus, operating time, and duration of external cerebrospinal fluid drainage prior to shunt placement) did not differ between the study and control groups. In the pediatric AISC group, the frequency of premature, shunt-treated infants and the incidence of external ventricular drainage prior to shunt insertion were actually higher than those in the non-AISC group. When using AISCs, the shunt infection rate dropped from 4 to 0.6% and from 13.6 to 3.8% in the adult and the pediatric cohort, respectively. Overall the infection rate decreased from 5.8 to 1%, which was statistically significant (p = 0.0145). The average costs of a single shunt infection were $17,300 and $13,000 in children and adults, respectively. The cost-benefit calculation assumed to have saved shunt infection-related costs of approximately $50,000 in 197 AISC-treated patients due to the reduction in shunt infection rate in this group compared with costs in the control group. Despite the incremental implant costs associated with the use of AISCs, the overall reduction in infection-related costs made the use of AISCs cost beneficial in the authors' department. From clinical and economic perspectives, AISCs are seemingly a valuable addition in hydrocephalus therapy.

Plasma cytokine concentrations in dogs with a congenital portosystemic shunt.

PubMed

Kilpatrick, Scott; Gow, Adam G; Foale, Rob D; Tappin, Simon W; Carruthers, Harvey; Reed, Nicola; Yool, Donald A; Woods, Samantha; Marques, Ana I; Jalan, Rajiv; Mellanby, Richard J

2014-04-01

Congenital portosystemic shunts (cPSS) are a well-recognised vascular anomaly in dogs. Recent studies have shown an association between inflammation and hepatic encephalopathy (HE), which is a common clinical syndrome in dogs with a cPSS. Pro-inflammatory cytokines such as interleukin (IL)-6 and tumour necrosis factor (TNF)-α are frequently increased in the plasma of human patients with liver disease and have been implicated in the development of HE. In the current study, plasma concentrations of IL-2, IL-6, IL-8 and TNF-α were measured using a multiplex electrochemiluminescence immunoassay in 36 dogs with a cPSS and compared to 25 healthy dogs. There were no significant differences in plasma IL-2, IL-8 and TNF-α concentrations between the two groups; however, plasma concentrations of IL-6 were significantly higher in dogs with a cPSS compared to healthy dogs (P=0.02). Copyright © 2014 Elsevier Ltd. All rights reserved.

[The current state of the surgery of portal hypertension].

PubMed

Mercado, M A; Orozco, H

1992-01-01

Surgery for bleeding portal hypertension has evolved widely in the last decades. The surgical procedures that preserve portal blood flow are the first operative choice for well selected patients. Operative procedures that deprive the portal blood flow to the liver, are most likely to promote deterioration of liver function in the late postoperative period. The operation most frequently performed are the selective shunts (Warren) and the thoraco abdominal devascularization (Sugiura). The best results are obtained in patients with a good liver function that are operated in an elective fashion. Non-selective shunts have a restricted indication and low diameter porto systemic shunts are still under evaluation. The combination of drug therapy and/or sclerotherapy with surgery appears to improve survival. Liver transplants are indicated for those patients with associated liver failure. For patients with good liver function, surgery is the therapy of choice.

A novel technique for ventriculoperitoneal shunting by flat panel detector CT-guided real-time fluoroscopy

PubMed Central

Kobayashi, Shinya; Ishikawa, Tatsuya; Mutoh, Tatsushi; Hikichi, Kentaro; Suzuki, Akifumi

2012-01-01

Background: Surgical placement of a ventriculoperitoneal shunt (VPS) is the main strategy to manage hydrocephalus. However, the failure rate associated with placement of ventricular catheters remains high. Methods: A hybrid operating room, equipped with a flat-panel detector digital subtraction angiography system containing C-arm cone-beam computed tomography (CB-CT) imaging, has recently been developed and utilized to assist neurosurgical procedures. We have developed a novel technique using intraoperative fluoroscopy and a C-arm CB-CT system to facilitate accurate placement of a VPS. Results: Using this novel technique, 39 consecutive ventricular catheters were placed accurately, and no ventricular catheter failures were experienced during the follow-up period. Only two patients experienced obstruction of the VPS, both of which occurred in the extracranial portion of the shunt system. Conclusion: Surgical placement of a VPS assisted by flat panel detector CT-guided real-time fluoroscopy enabled accurate placement of ventricular catheters and was associated with a decreased need for shunt revision. PMID:23226605

Noninvasive scoring system for significant inflammation related to chronic hepatitis B

NASA Astrophysics Data System (ADS)

Hong, Mei-Zhu; Ye, Linglong; Jin, Li-Xin; Ren, Yan-Dan; Yu, Xiao-Fang; Liu, Xiao-Bin; Zhang, Ru-Mian; Fang, Kuangnan; Pan, Jin-Shui

2017-03-01

Although a liver stiffness measurement-based model can precisely predict significant intrahepatic inflammation, transient elastography is not commonly available in a primary care center. Additionally, high body mass index and bilirubinemia have notable effects on the accuracy of transient elastography. The present study aimed to create a noninvasive scoring system for the prediction of intrahepatic inflammatory activity related to chronic hepatitis B, without the aid of transient elastography. A total of 396 patients with chronic hepatitis B were enrolled in the present study. Liver biopsies were performed, liver histology was scored using the Scheuer scoring system, and serum markers and liver function were investigated. Inflammatory activity scoring models were constructed for both hepatitis B envelope antigen (+) and hepatitis B envelope antigen (-) patients. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve were 86.00%, 84.80%, 62.32%, 95.39%, and 0.9219, respectively, in the hepatitis B envelope antigen (+) group and 91.89%, 89.86%, 70.83%, 97.64%, and 0.9691, respectively, in the hepatitis B envelope antigen (-) group. Significant inflammation related to chronic hepatitis B can be predicted with satisfactory accuracy by using our logistic regression-based scoring system.

Turning crocodilian hearts into bird hearts: growth rates are similar for alligators with and without right-to-left cardiac shunt

PubMed Central

Eme, John; Gwalthney, June; Owerkowicz, Tomasz; Blank, Jason M.; Hicks, James W.

2010-01-01

The functional and possible adaptive significance of non-avian reptiles' dual aortic arch system and the ability of all non-avian reptiles to perform central vascular cardiac shunts have been of great interest to comparative physiologists. The unique cardiac anatomy of crocodilians – a four-chambered heart with the dual aortic arch system – allows for only right-to-left (R–L; pulmonary bypass) cardiac shunt and for surgical elimination of this shunt. Surgical removal of the R–L shunt, by occluding the left aorta (LAo) upstream and downstream of the foramen of Panizza, results in a crocodilian with an obligatory, avian/mammalian central circulation. In this study, R–L cardiac shunt was eliminated in age-matched, female American alligators (Alligator mississippiensis; 5–7 months of age). We tested the hypothesis that surgical elimination of R–L cardiac shunt would impair growth (a readily measured proxy for fitness) compared with sham-operated, age-matched controls, especially in animals subjected to exhaustive exercise. While regular exercise caused a decrease in size (snout-to-vent length, head length and body mass), elimination of the capacity for R–L cardiac shunt did not greatly reduce animal growth, despite a chronic ventricular enlargement in surgically altered juvenile alligators. We speculate that, despite being slightly smaller, alligators with an occluded LAo would have reached sexual maturity in the same breeding season as control alligators. This study suggests that crocodilian R–L cardiac shunt does not provide an adaptive advantage for juvenile alligator growth and supports the logic that cardiac shunts persist in crocodilians because they have not been selected against. PMID:20639429

Pulmonary hypertension in patients with congenital portosystemic venous shunt: a previously unrecognized association.

PubMed

Ohno, Takuro; Muneuchi, Jun; Ihara, Kenji; Yuge, Tetsuji; Kanaya, Yoshiaki; Yamaki, Shigeo; Hara, Toshiro

2008-04-01

Pulmonary arterial hypertension has been reported to be observed in association with acquired portal hypertension. However, the contribution of congenital anomalies occurring in the portal system to the development of pulmonary arterial hypertension remains to be elucidated. Nine patients with congenital portosystemic venous shunt were studied from January 1990 through September 2005. Patent ductus venosus was detected in 5 patients, including 3 patients with an absence of the portal vein. The presence of either a gastrorenal or splenorenal shunt was evident in another 4 patients. Six patients had a history of hypergalactosemia with normal enzyme activities, as seen during neonatal screening. Six (66.7%) of the 9 patients were identified to have clinically significant pulmonary arterial hypertension (mean pulmonary artery pressure: 34-79 mm Hg; pulmonary vascular resistances: 5.12-38.07 U). The median age at the onset of pulmonary arterial hypertension was 12 years and 3 months. Histologic studies of lung specimens, which were available in 4 of the 9 patients with congenital portosystemic venous shunt, showed small arterial microthrombotic lesions in 3 patients. This characteristic finding was recognized even in the congenital portosystemic venous shunt patients without PAH. This study demonstrated thromboembolic pulmonary arterial hypertension to be a crucial complication in congenital portosystemic venous shunt, and this pathologic state may be latently present in patients with pulmonary arterial hypertension of unknown etiology.

ZigBee-based wireless intra-oral control system for quadriplegic patients.

PubMed

Peng, Qiyu; Budinger, Thomas F

2007-01-01

A human-to-computer system that includes a wireless intra-oral module, a wireless coordinator and distributed wireless controllers, is presented. The state-of-the-art ZigBee protocol is employed to achieve reliable, low-power and cost-efficient wireless communication between the tongue, computer and controllers. By manipulating five buttons on the wireless intra-oral module using the tongue, the subject can control cursors, computer menus, wheelchair, lights, TV, phone and robotic devices. The system is designed to improve the life quality of patients with stroke and patients with spinal cord injury.

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

PubMed

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

2012-06-01

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

A Case of Left Renal Vein Ligation in a Patient with Solitary Left Kidney Undergoing Liver Transplantation to Control Splenorenal Shunt and Improve Portal Venous Flow.

PubMed

Martino, Rodrigo B; Júnior, Eserval Rocha; Manuel, Valdano; Rocha-Santos, Vinicius; D'Albuquerque, Luis Augusto C; Andraus, Wellington

2017-10-11

BACKGROUND Adequate portal venous flow is required for successful liver transplantation. Reduced venous flow and blood flow 'steal' by collateral vessels are a concern, and when there is a prominent splenorenal shunt present, ligation of the left renal vein has been recommended to improve portal venous blood flow. CASE REPORT A 51-year-old man who had undergone right nephrectomy in childhood required liver transplantation for liver cirrhosis and hepatocellular carcinoma due to hepatitis C virus (HCV) infection. The patient had no other comorbidity and no history of hepatorenal syndrome. At transplantation surgery, portal venous flow was poor and did not improve with ligation of shunt veins, but ligation of the left renal vein improved portal venous flow. On the first and fifth postoperative days, the patient was treated with basiliximab, a chimeric monoclonal antibody to the IL-2 receptor, and methylprednisolone. The calcineurin inhibitor, tacrolimus, was introduced on the fifth postoperative day. On the sixteenth postoperative day, renal color Doppler ultrasound showed normal left renal parenchyma; hepatic Doppler ultrasound showed good portal vein flow and preserved hepatic parenchyma in the liver transplant. CONCLUSIONS This case report has shown that in a patient with a single left kidney, left renal vein ligation is feasible and safe in a patient with no other risk factors for renal impairment following liver transplantation. Modification of postoperative immunosuppression to avoid calcineurin inhibitors in the very early postoperative phase may be important in promoting good recovery of renal function and to avoid the need for postoperative renal dialysis.

Calibration of piezoelectric RL shunts with explicit residual mode correction

NASA Astrophysics Data System (ADS)

Høgsberg, Jan; Krenk, Steen

2017-01-01

Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominant vibration modes of a flexible structure and their efficiency relies on the precise calibration of the shunt components. In the present paper improved calibration accuracy is attained by an extension of the local piezoelectric transducer displacement by two additional terms, representing the flexibility and inertia contributions from the residual vibration modes not directly addressed by the shunt damping. This results in an augmented dynamic model for the targeted resonant vibration mode, in which the residual contributions, represented by two correction factors, modify both the apparent transducer capacitance and the shunt circuit impedance. Explicit expressions for the correction of the shunt circuit inductance and resistance are presented in a form that is generally applicable to calibration formulae derived on the basis of an assumed single-mode structure, where modal interaction has been neglected. A design procedure is devised and subsequently verified by a numerical example, which demonstrates that effective mitigation can be obtained for an arbitrary vibration mode when the residual mode correction is included in the calibration of the RL shunt.

Three-dimensional Image Fusion Guidance for Transjugular Intrahepatic Portosystemic Shunt Placement.

PubMed

Tacher, Vania; Petit, Arthur; Derbel, Haytham; Novelli, Luigi; Vitellius, Manuel; Ridouani, Fourat; Luciani, Alain; Rahmouni, Alain; Duvoux, Christophe; Salloum, Chady; Chiaradia, Mélanie; Kobeiter, Hicham

2017-11-01

To assess the safety, feasibility and effectiveness of image fusion guidance with pre-procedural portal phase computed tomography with intraprocedural fluoroscopy for transjugular intrahepatic portosystemic shunt (TIPS) placement. All consecutive cirrhotic patients presenting at our interventional unit for TIPS creation from January 2015 to January 2016 were prospectively enrolled. Procedures were performed under general anesthesia in an interventional suite equipped with flat panel detector, cone-beam computed tomography (CBCT) and image fusion technique. All TIPSs were placed under image fusion guidance. After hepatic vein catheterization, an unenhanced CBCT acquisition was performed and co-registered with the pre-procedural portal phase CT images. A virtual path between hepatic vein and portal branch was made using the virtual needle path trajectory software. Subsequently, the 3D virtual path was overlaid on 2D fluoroscopy for guidance during portal branch cannulation. Safety, feasibility, effectiveness and per-procedural data were evaluated. Sixteen patients (12 males; median age 56 years) were included. Procedures were technically feasible in 15 of the 16 patients (94%). One procedure was aborted due to hepatic vein catheterization failure related to severe liver distortion. No periprocedural complications occurred within 48 h of the procedure. The median dose-area product was 91 Gy cm 2 , fluoroscopy time 15 min, procedure time 40 min and contrast media consumption 65 mL. Clinical benefit of the TIPS placement was observed in nine patients (56%). This study suggests that 3D image fusion guidance for TIPS is feasible, safe and effective. By identifying virtual needle path, CBCT enables real-time multiplanar guidance and may facilitate TIPS placement.

Patent Foramen Ovale: Association between the Degree of Shunt by Contrast Transesophageal Echocardiography and the Risk of Future Ischemic Neurologic Events

NASA Technical Reports Server (NTRS)

Stone, David A.; Godard, Joel; Godard, Joel; Corretti, mary C.; Kittner, Steven J.; Sample, Cindy; Price, Thomas R.; Plotnick, Gary D.

1996-01-01

This study investigated whether there is an association between the degree of interatrial shunting across a patent foramen ovale, as determined by saline contrast transesophageal echocardiography, and the risk of subsequent systemic embolic events, including stroke. Thirty-four patients found to have patent foramen ovale during transesophageal echocardiography were divided into two groups on the basis of the maximum number of microbubbles in the left heart in any single frame after intravenous saline contrast injection: group 1 (n = 16) with a "large" degree of shunt (220 microbubbles) and group 2 (n = 18) with a "small" degree of shunt (23 but <20 microbubbles). Patients were followed up over a mean period of 21 months for subsequent systemic embolic events, including transient ischemic attack and stroke. Five (31%) of the patients with large shunts had subsequent ischemic neurologic events, whereas none of the patients with small shunts had embolic events (p= 0.03). These events occurred in spite of antiplatelet or anticoagulant therapy. We conclude that patients with a large degree of shunt across a patent foramen ovale, as determined by contrast transesophageal echocardiography, are at a significantly higher risk for subsequent adverse neurologic events compared with patients with a small degree of shunt.

Ventriculoperitoneal Shunt Fracture Following Application of Halo-Gravity Traction: A Case Report.

PubMed

Blakeney, William G; D'Amato, Charles

2015-09-01

Ventriculoperitoneal (VP) shunt malfunctions are very common, and shunt fracture is one of the most common causes. Shunt fractures are often a result of calcification and tethering, which predispose the tubing to fracture when mechanical stresses are applied. This case report describes a case of shunt fracture following application of halo-gravity traction for correction of spinal deformity. Chart and imaging data for a single case were reviewed and reported in this retrospective case study. A 10-year-old female, being treated for syndromic scoliosis, underwent posterior surgical release and application of halo-gravity traction. Increasing weight of traction was applied over a period of 6 weeks, for gradual deformity correction. It was noted on the 6-week cervical spine radiograph that the VP shunt had fractured at the base of the neck. The patient was taken to the operating room and intraoperative findings confirmed shunt fracture. This was repaired without complications. This case, to our best knowledge, is the first reported occurrence of shunt fracture following application of halo-gravity traction. It demonstrates the importance of careful monitoring of patients with VP shunts, when they are undergoing traction for correction of spinal deformity. Level IV.

Liver metastases from melanoma: hepatic intra-arterial chemotherapy. A retrospective study.

PubMed

Farolfi, A; Ridolfi, L; Guidoboni, M; Milandri, C; Calzolari, F; Scarpi, E; Amadori, D; Ridolfi, R

2011-10-01

The liver is the primary site of metastases in most uveal melanoma patients. We retrospectively investigated intraarterial chemotherapy (IAC) as treatment for patients with hepatic melanoma metastases.Twenty-three patients (18 with uveal melanoma) received fotemustine (14 patients, 61.9%) or carboplatin (9 patients, 31.1%) via hepatic IAC delivery. The catheter was introduced through percutaneous access to the femoral artery with drugs delivered directly to the hepatic artery, and was removed at the end of each treatment cycle. A total of 3 cycles was planned, repeated every 21 days. However, patients with a clinical response could receive more than 3 cycles, provided that the toxic effects were acceptable.IAC was well tolerated and no catheter-related complications or grade 4 toxicities were reported. Considering only uveal melanoma patients, the overall response rate and disease control rate was 16.7% and 38.9%, respectively. Median time to progression was 6.2 months (95% CI 3.7-10.5) and median overall survival was 21 months (95% CI 8-39).IAC is well tolerated and is a valid choice for patients with a poor prognosis since median survival rates are among the longest reported.

Current state of knowledge of hepatic encephalopathy (part IV): Management of Hepatic Encephalopathy by liver support systems.

PubMed

Hassanein, Tarek

2017-04-01

Hepatic Encephalopathy is a devastating complication of End-Stage Liver Disease. In its severe grades it requires extra intervention beyond the standard medical approaches. In this article were view the role of liver support systems in managing hepatic encephalopthy.

Application to processing system using intra-molecular BRET

NASA Astrophysics Data System (ADS)

Otsuji, Tomomi; Okuda-Ashitaka, Emiko; Kojima, Satoshi; Akiyama, Hidehumi; Ito, Seiji; Ohmiya, Yoshihiro

2003-07-01

Luciferases are used as the reporter gene for promoter activity, whereas a green fluorescent protein (GFP) is used as marker for cellular function and localization. Recently, bioluminescence resonance energy transfer (BRET) between luciferase and YFP is used for analysis of inter-molecular reaction such as ligand-receptor in the living cells. The neuropeptides nocistatin (NST) and nociceptin/orphanin FQ (Noc/OFQ) are derived from the same precursor protein, while NST exhibits antagonism against Noc/OFQ-actions. In this study, we attempt an intra-molecular BRET system for monitoring dynamic biological process of the production of NST and Noc/OFQ in the living cells. At first, we constructed a fusion protein (Rluc-GFP) covalently linking luciferase (Renilla luciferase; Rluc) to Aequorea GFP as an intra-molecular BRET partner. Furthermore, we inserted constructs of mouse NST and Noc/OFQ (Rluc-m-GFP) or bovine NST and Noc/OFQ (Rluc-b-GFP) containing a proteolytic cleavage motif (Lys-Arg) within Rluc-GFP. When these constructions were transfected into Cos7 cells, all fusion proteins had luciferase activity and specific fluorescence. Luminescence spectra of Rluc-GFP, Rluc-m-GFP and Rluc-b-GFP fusion proteins with DeepBlueC as a substrate showed two peaks centered at 400 nm and 510 nm, whereas Rluc showed one peak centered at 400 nm. These results indicate that the proteolytic cleavage motif inserted fusion proteins between luciferase and GFP are available for intra-molecular BRET systems at first step.

Parent ratings of executive functioning in children with shunted hydrocephalus.

PubMed

Lacy, Maureen; Baldassarre, Megan; Nader, Todd; Frim, David

2012-01-01

The present study examined the executive functioning of a group of children with a history of communicating hydrocephalus and how their level of functioning was correlated with parent ratings of executive functioning. The study examined the executive functioning of 39 shunted children with a history of hydrocephalus and 20 healthy peers. Additionally, parents of both groups of children completed the Behavior Rating Inventory of Executive Function (BRIEF) to assess the parents' perceptions of their children's executive functioning. Finally, the study investigated the relationship between the shunted hydrocephalus children's executive functioning and the parent ratings of their executive functioning. Overall, the children with a history of shunted hydrocephalus displayed more executive dysfunction than their healthy peers. These children were rated by their parents as having more executive dysfunction than their healthy peers and displaying working memory, initiation, mental flexibility and self-monitoring difficulties, which appear to increase with age among the shunted hydrocephalus group. While parent ratings as measured by the BRIEF indices did not correlate with all executive tasks within the shunted hydrocephalus group, the cognitive tests assessing mental flexibility may be sensitive to the problems noted by parents at home. The children with a history of shunted hydrocephalus displayed executive functioning deficits on formal examination. The parents of children with a history of shunted hydrocephalus report ongoing executive difficulties which may increase with age. Copyright © 2012 S. Karger AG, Basel.

Research of vibration control based on current mode piezoelectric shunt damping circuit

NASA Astrophysics Data System (ADS)

Liu, Weiwei; Mao, Qibo

2017-12-01

The piezoelectric shunt damping circuit using current mode approach is imposed to control the vibration of a cantilever beam. Firstly, the simulated inductance with large values are designed for the corresponding RL series shunt circuits. Moreover, with an example of cantilever beam, the second natural frequency of the beam is targeted to control for experiment. By adjusting the values of the equivalent inductance and equivalent resistance of the shunt circuit, the optimal damping of the shunt circuit is obtained. Meanwhile, the designed piezoelectric shunt damping circuit stability is experimental verified. Experimental results show that the proposed piezoelectric shunt damping circuit based on current mode circuit has good vibration control performance. However, the control performance will be reduced if equivalent inductance and equivalent resistance values deviate from optimal values.

Electrospun polyurethane as an alternative ventricular catheter and in vitro model of shunt obstruction

PubMed Central

Suresh, Supraja

2015-01-01

Intracranial pressure and volume vary considerably between hydrocephalic patients, and with age, health and haemodynamic status; if left untreated, intracranial pressure rises and the ventricular system expands to accommodate the excess cerebrospinal fluid, with significant morbidity and mortality. Cerebrospinal fluid shunts in use today have a high incidence of failure with shunt obstruction being the most serious. Conventional proximal shunt catheters are made from poly(dimethyl)siloxane, the walls of which are perforated with holes for the cerebrospinal fluid to pass through. The limited range of catheters, in terms of material selection and flow distribution, is responsible in large part for their poor performance. In this study, we present an alternative design of proximal catheter made of electrospun polyether urethane, and evaluate its performance in the presence of glial cells, which are responsible for shunt blockage. The viability and growth of cells on catheter materials such as poly(dimethyl)siloxane and polyurethane in the form of cast films, microfibrous mats and porous sponges were studied in the presence of proteins present in cerebrospinal fluid after 48 h and 96 h in culture. The numbers of viable cells on each substrate were comparable to untreated poly(dimethyl)siloxane, both in the presence and absence of serum proteins found in cerebrospinal fluid. A cell culture model of shunt obstruction was developed in which cells on electrospun polyether urethane catheters were subjected to flow during culture in vitro, and the degree of obstruction quantified in terms of hydraulic permeability after static and perfusion culture. The results indicate that a catheter made of electrospun polyether urethane would be able to maintain cerebrospinal fluid flow even with the presence of cells for the time period chosen for this study. These findings have implications for the design and deployment of microporous shunt catheter systems for the treatment of

Extrahepatic portosystemic shunt in congenital absence of the portal vein depicted by time-resolved contrast-enhanced MR angiography.

PubMed

Goo, Hyun Woo

2007-07-01

Congenital absence of the portal vein is a rare malformation in which mesenteric and splenic venous flow bypasses the liver and drains into various sites in the systemic venous system via an extrahepatic portosystemic shunt. In an 11-year-old girl with congenital absence of the portal vein, the detailed anatomy of the extrahepatic portosystemic shunt is demonstrated by time-resolved contrast-enhanced MR angiography.

Listeria monocytogenes: a Rare Complication of Ventriculoperitoneal Shunt in Children ▿

PubMed Central

Le Monnier, Alban; Blanot, Stéphane; Abachin, Eric; Beretti, Jean-Luc; Berche, Patrick; Kayal, Samer

2011-01-01

We report a case of ventriculoperitoneal (VP) shunt infection in a 3-year-old boy caused by the food-borne pathogen Listeria monocytogenes, subsequent to acute peritonitis. This unusual presentation of central nervous system (CNS) listeriosis underlines the ability of the bacteria to form and survive within biofilms on indwelling medical devices. Bacterial persistence may lead to treatment failure and spreading. We highlight the helpfulness of specific quantitative real-time PCR for the hly gene (PCR-hly) for the diagnosis and follow-up of such infections in detecting bacterial persistence within medical devices despite effective antibiotic treatment. Only the surgical replacement of the VP shunt will resolve the infection. PMID:21918024

Clinical outcomes of temporary shunting for infants with cerebral pseudomeningocele.

PubMed

Mattei, Tobias A; Sambhara, Deepak; Bond, Brandon J; Lin, Julian

2014-02-01

Although in the case of subdural collections temporary shunting has been suggested as a viable alternative for definitive drainage of the accumulated fluid until restoration of the normal CSF dynamics, there is no agreement on the best management strategy for pseudomeningocele. The authors performed a retrospective chart review in order to evaluate the clinical outcomes of infants temporarily shunted for pseudomeningocele without encephalocele at our institution (The University of Illinois at Peoria/Illinois Neurological Institute) in the period from 2004 to 2012. The epidemiological characteristics, clinical management, and final outcomes of such subpopulation were compared with a control group which received temporary shunting for subdural hematomas (SDH) during the same period. Four patients (100% male) ranging in age from 8.9 to 27.1 months (mean = 13.88) with pseudomeningocele and 17 patients (64.7% male) ranging in age from 1.9 to 11.8 months (mean = 4.15) with SDH were identified. Although the initial management included sequential percutaneous subdural tapping in 82% of the patients, all children ultimately failed such strategy, requiring either subdural-peritoneal (81% of the cases) or subgaleal-peritoneal (19% of the cases) shunting. The mean implant duration was 201 days for the pseudomeningocele group and 384 days for the SDH one. Mean post-shunt hospitalization was 2 days for patients with pseudomeningocele and 4 days for patients with SDH. There was no statistical difference in terms of complications, length of hospitalization post-shunting, or clinical outcomes between the patients with pseudomeningocele and those with SDH. Temporary shunting of infants with pseudo-meningocele constitutes a viable therapeutic alternative with favorable clinical outcomes and a low risk of shunt dependency similar to those of children with SDH.

Universality of Non-Ohmic Shunt Leakage in Thin-Film Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dongaonkar, S.; Servaites, J.D.; Ford, G.M.

2010-01-01

We compare the dark current-voltage (IV) characteristics of three different thin-film solar cell types: hydrogenated amorphous silicon (a-Si:H) p-i-n cells, organic bulk heterojunction (BHJ) cells, and Cu(In,Ga)Se 2 (CIGS) cells. All three device types exhibit a significant shunt leakage current at low forward bias (V<~0.4) and reverse bias, which cannot be explained by the classical solar cell diode model. This parasitic shunt current exhibits non-Ohmic behavior, as opposed to the traditional constant shunt resistance model for photovoltaics. We show here that this shunt leakage (I sh) , across all three solar cell types considered, is characterized by the following commonmore » phenomenological features: (a) voltage symmetry about V=0 , (b) nonlinear (power law) voltage dependence, and (c) extremely weak temperature dependence. Based on this analysis, we provide a simple method of subtracting this shunt current component from the measured data and discuss its implications on dark IV parameter extraction. We propose a space charge limited (SCL) current model for capturing all these features of the shunt leakage in a consistent framework and discuss possible physical origin of the parasitic paths responsible for this shunt current mechanism.« less

A physical framework for implementing virtual models of intracranial pressure and cerebrospinal fluid dynamics in hydrocephalus shunt testing.

PubMed

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

2016-09-01

OBJECTIVE The surgical placement of a shunt designed to resolve the brain's impaired ability to drain excess CSF is one of the most common treatments for hydrocephalus. The use of a dynamic testing platform is an important part of shunt testing that can faithfully reproduce the physiological environment of the implanted shunts. METHODS A simulation-based framework that serves as a proof of concept for enabling the application of virtual intracranial pressure (ICP) and CSF models to a physical shunt-testing system was engineered. This was achieved by designing hardware and software that enabled the application of dynamic model-driven inlet and outlet pressures to a shunt and the subsequent measurement of the resulting drainage rate. RESULTS A set of common physiological scenarios was simulated, including oscillations in ICP due to respiratory and cardiac cycles, changes in baseline ICP due to changes in patient posture, and transient ICP spikes caused by activities such as exercise, coughing, sneezing, and the Valsalva maneuver. The behavior of the Strata valve under a few of these physiological conditions is also demonstrated. CONCLUSIONS Testing shunts with dynamic ICP and CSF simulations can facilitate the optimization of shunts to be more failure resistant and better suited to patient physiology.

Are Shunt Revisions Associated with IQ in Congenital Hydrocephalus? A Meta -Analysis.

PubMed

Arrington, C Nikki; Ware, Ashley L; Ahmed, Yusra; Kulesz, Paulina A; Dennis, Maureen; Fletcher, Jack M

2016-12-01

Although it is generally acknowledged that shunt revisions are associated with reductions in cognitive functions in individuals with congenital hydrocephalus, the literature yields mixed results and is inconclusive. The current study used meta-analytic methods to empirically synthesize studies addressing the association of shunt revisions and IQ in individuals with congenital hydrocephalus. Six studies and three in-house datasets yielded 11 independent samples for meta-analysis. Groups representing lower and higher numbers of shunt revisions were coded to generate effect sizes for differences in IQ scores. Mean effect size across studies was statistically significant, but small (Hedges' g = 0.25, p < 0.001, 95 % CI [0.08, 0.43]) with more shunt revisions associated with lower IQ scores. Results show an association of lower IQ and more shunt revisions of about 3 IQ points, a small effect, but within the error of measurement associated with IQ tests. Although clinical significance of this effect is not clear, results suggest that repeated shunt revisions because of shunt failure is associated with a reduction in cognitive functions.

Stability of Programmable Shunt Valve Settings with Simultaneous Use of the Optune Transducer Array: A Case Report.

PubMed

Chan, Andrew K; Birk, Harjus S; Winkler, Ethan A; Viner, Jennifer A; Taylor, Jennie W; McDermott, Michael W

2016-07-07

The Optune® transducer array (Novocure Ltd., Haifa, Israel) is an FDA-approved noninvasive regional therapy that aims to inhibit the growth of glioblastoma multiforme (GBM) cells via utilization of alternating electric fields. Some patients with GBM may develop hydrocephalus and benefit from subsequent shunt placement, but special attention must be paid to patients in whom programmable valves are utilized, given the potential effect of the magnetic fields on valve settings. We present the first case report illustrating the stability of programmable shunt valve settings in a neurosurgical patient undergoing therapy with the Optune device. In this study, shunt valve settings were stable over a period of five days despite Optune therapy. This is reassuring for patients with GBM who require simultaneous treatment with both the Optune device and a programmable shunt system.

Intrinsically shunted Josephson junctions for electronics applications

NASA Astrophysics Data System (ADS)

Belogolovskii, M.; Zhitlukhina, E.; Lacquaniti, V.; De Leo, N.; Fretto, M.; Sosso, A.

2017-07-01

Conventional Josephson metal-insulator-metal devices are inherently underdamped and exhibit hysteretic current-voltage response due to a very high subgap resistance compared to that in the normal state. At the same time, overdamped junctions with single-valued characteristics are needed for most superconducting digital applications. The usual way to overcome the hysteretic behavior is to place an external low-resistance normal-metal shunt in parallel with each junction. Unfortunately, such solution results in a considerable complication of the circuitry design and introduces parasitic inductance through the junction. This paper provides a concise overview of some generic approaches that have been proposed in order to realize internal shunting in Josephson heterostructures with a barrier that itself contains the desired resistive component. The main attention is paid to self-shunted devices with local weak-link transmission probabilities that are so strongly disordered in the interface plane that transmission probabilities are tiny for the main part of the transition region between two super-conducting electrodes, while a small part of the interface is well transparent. We discuss the possibility of realizing a universal bimodal distribution function and emphasize advantages of such junctions that can be considered as a new class of self-shunted Josephson devices promising for practical applications in superconducting electronics operating at 4.2 K.

Three-year outcome of shunted idiopathic NPH patients.

PubMed

Aygok, G; Marmarou, A; Young, H F

2005-01-01

The incidence of idiopathic normal pressure hydrocephalus (iNPH) has increased as a result of improved longevity. This report describes the 3-year outcome of shunted iNPH patients compared to three-month outcome after shunting. Patients (n = 50) (Age 70.4 +/- 8.9) admitted to our service were diagnosed and treated according to a fixed protocol for management of iNPH and after shunting were followed at least three times per year in clinic. The outcome of 50 patients was graded according to the level of improvement in symptoms as Excellent/Good, Partial or None in each category of Gait, Incontinence and Dementia. If we lump favorable (excellent, good, partial recovery) vs poor recovery (none), we found from 3 months to 3 years, a moderate decline in gait performance (91% to 75%), a retention of memory improvement (80%-80%) and an improvement in incontinence occurred over time (70%-82.5%). With proper diagnosis and management of iNPH, shunting of patients is associated with a favorable risk/benefit ratio that is reasonably long lasting.

Influence of time delay on the estimated lung shunt fraction on 99mTc-labeled MAA scintigraphy for 90Y microsphere treatment planning.

PubMed

De Gersem, Ruth; Maleux, Geert; Vanbilloen, Hubert; Baete, Kristof; Verslype, Chris; Haustermans, Karin; Verbruggen, Alfons; Van Cutsem, Eric; Deroose, Christophe Michel

2013-12-01

90Y-microspheres therapy is used to treat selected patients with primary or metastatic liver tumors in a safe and effective way. As a preparation for 90Y-microspheres treatment, a 99mTc-macroaggregated albumin (99mTc-MAA) simulation procedure is essential to evaluate particle shunting to the lung or gastrointestinal tract. We investigated the effect of interval between injection of 99mTc-MAA and time of scanning on the lung shunt fraction (LSF). In 4 patients with secondary hepatic malignancies who underwent repeated whole-body scintigraphy up to 5 hours after injection of 99mTc-MAA, a marked change in LSF was observed. It appears that tracer degradation leads to an important overestimation of LSF at later time points. An overestimation of LSF can lead to dose reduction or canceling of the planned 90Y-microspheres treatment. It is concluded that the interval between injection and scanning should be kept as short as possible.

Glaucoma Mini-Shunt Implantation After Keratoplasty.

PubMed

Ledesma-Gil, Jasbeth; García-Rodríguez, María de Los Ángeles; Gurria, Lulu U; Graue-Hernández, Enrique O; Navas, Alejandro

2017-04-01

To report the outcomes of patients who underwent miniature glaucoma shunt implantation after secondary glaucoma due to keratoplasty. Prospective study of consecutive clinical cases who underwent mini-glaucoma shunt implantation following keratoplasty. In brief, a fornix-based conjunctival flap was performed, approximately 50% thickness scleral flap. Mitomycin C 0.025% placed under Tenon's capsule. A 25-G needle created entry for mini-shunt. Ex-PRESS model P-50 was inserted. Scleral flap and conjunctiva were closed with 10-0 Nylon. STATA 8.0 and SPSS software were used for statistical analysis. Seventeen eyes of 17 patients with a mean age of 39.70 years (SD=18.33, range: 18 to 76). A total of 64.70% were male and 35.30% female. Eleven cases after penetrating keratoplasty, 3 cases after triple procedure, 2 after deep anterior lamellar keratoplasty, and 1 following endothelial keratoplasty. Most of the indications for keratoplasty were keratoconus in 9 cases (52.94%), 4 due to endothelial failure (23.52%), 3 cases of herpetic keratitis (17.64%), and 1 case of post-LASIK ectasia (5.88%). Mean preoperative intraocular pressure was 35.94 mm Hg with maximal medical therapy (SD=9.65, range: 18 to 55). Decreasing intraocular pressure to 12.76 mm Hg postoperatively (SD=2.51, range 10 to 18) (P=0.001). Mean follow-up after mini-glaucoma shunt implantation was 23.76 months (SD=8.73, range: 10 to 35 mo). Preoperative mean uncorrected distance visual acuity (UDVA) was 1.31±0.63 (20/408 Snellen) and postoperative mean UDVA was 0.85±0.40 (20/141 Snellen) (P=0.001). Preoperative mean corrected distance visual acuity (CDVA) was 0.83±0.76 (20/135 Snellen) and postoperative mean CDVA was 0.56±0.44 (20/72 Snellen) (P=0.032). Ex-PRESS miniature glaucoma shunt could be an alternative treatment in postkeratoplasty glaucoma resistant to medical treatment. This technique may be helpful, in trying to avoid corneal damage produced by conventional glaucoma procedures.

PI and fuzzy logic controllers for shunt Active Power Filter--a report.

PubMed

P, Karuppanan; Mahapatra, Kamala Kanta

2012-01-01

This paper presents a shunt Active Power Filter (APF) for power quality improvements in terms of harmonics and reactive power compensation in the distribution network. The compensation process is based only on source current extraction that reduces the number of sensors as well as its complexity. A Proportional Integral (PI) or Fuzzy Logic Controller (FLC) is used to extract the required reference current from the distorted line-current, and this controls the DC-side capacitor voltage of the inverter. The shunt APF is implemented with PWM-current controlled Voltage Source Inverter (VSI) and the switching patterns are generated through a novel Adaptive-Fuzzy Hysteresis Current Controller (A-F-HCC). The proposed adaptive-fuzzy-HCC is compared with fixed-HCC and adaptive-HCC techniques and the superior features of this novel approach are established. The FLC based shunt APF system is validated through extensive simulation for diode-rectifier/R-L loads. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Infectious complications related to external ventricular shunt. Incidence and risk factors.

PubMed

López-Amor, L; Viña, L; Martín, L; Calleja, C; Rodríguez-García, R; Astola, I; Forcelledo, L; Álvarez-García, L; Díaz-Gómez, C; Fernández-Domínguez, J; Vázquez, F; Escudero, D

2017-10-01

Infectious complications related to external ventricular shunt (ICREVS) are a main problem in neurocritical intensive care units (ICU). The aim of the review is to assess the incidence of ICREVS and to analyse factors involved. Retrospective analysis, adult polyvalent ICU in a third level reference hospital. Patients carrying external ventricular shunt (DVE) were included. Those patients with central nervous system infection diagnosed prior DVE placement were excluded. 87 patients were included with 106 DVE. Most common admittance diagnosis was subarachnoid haemorrhage (49.4%). 31 patients with 32 DVE developed an ICREVS. Infection rate is 19.5 per 1000 days of shunt for ICREVS and 14 per 1000 days for ventriculitis. 31.6% of the patients developed ICREVS and 25.3% ventriculitis. Patients who developed ICREVS presented higher shunt manipulations (2.0 ± 0.6 vs. 3.26 ± 1.02, p=0.02), shunt repositioning (0.1 ± 0.1 vs. 0.2 ± 0.1) and ICU and hospital stay (29.8 ± 4.9 vs 49.8 ± 5.2, p<0.01 y 67.4 ± 18.8 vs. 108.9 ± 30.2, p=0.02. Those DVE with ICREVS were placed for longer not only at infection diagnosis but also at removal (12.6 ± 2.1 vs. 18.3 ± 3.6 and 12.6 ± 2.1 vs. 30.4 ± 7.3 days, p<0.01). No difference in mortality was found. One out of three patients with a DVE develops an infection. The risk factors are the number of manipulations, repositioning and the permanency days. Patients with ICREVS had a longer ICU and hospital average stay without an increase in mortality.

Pulmonary Arteriovenous Malformations After the Superior Cavopulmonary Shunt: Mechanisms and Clinical Implications

PubMed Central

Kavarana, Minoo N.; Jones, Jeffrey A.; Stroud, Robert E.; Bradley, Scott M.; Ikonomidis, John S.; Mukherjee, Rupak

2015-01-01

Children with functional single ventricle heart disease are commonly palliated down a staged clinical pathway toward a Fontan completion procedure (total cavopulmonary connection). The Fontan physiology is fraught with long term complications associated with lower body systemic venous hypertension, eventually resulting in significant morbidity and mortality. The bidirectional Glenn shunt or superior cavopulmonary connection (SCPC) is commonly the transitional stage in single ventricle surgical management and provides excellent palliation. Some studies have demonstrated lower morbidity and mortality with the SCPC when compared with the Fontan. Unfortunately the durability of the SCPC is significantly limited by the development of pulmonary arteriovenous malformations (PAVMs) which have been commonly attributed to the absence of hepatic venous blood flow and the lack of pulsatile flow to the affected lungs. Abnormal angiogenesis has been suggested as a final common pathway to PAVM development. Understanding these fundamental mechanisms through the investigation of angiogenic pathways associated with the pathogenesis of PAVMs would help to develop medical therapies that could prevent or reverse this complication following SCPC. Such therapies could improve the longevity of the SCPC, potentially eliminate or significantly postpone the Fontan completion with its associated complications, and improve long-term survival in children with single ventricle disease. PMID:24758411

Shunted Piezoelectric Vibration Damping Analysis Including Centrifugal Loading Effects

NASA Technical Reports Server (NTRS)

Min, James B.; Duffy, Kirsten P.; Provenza, Andrew J.

2011-01-01

Excessive vibration of turbomachinery blades causes high cycle fatigue problems which require damping treatments to mitigate vibration levels. One method is the use of piezoelectric materials as passive or active dampers. Based on the technical challenges and requirements learned from previous turbomachinery rotor blades research, an effort has been made to investigate the effectiveness of a shunted piezoelectric for the turbomachinery rotor blades vibration control, specifically for a condition with centrifugal rotation. While ample research has been performed on the use of a piezoelectric material with electric circuits to attempt to control the structural vibration damping, very little study has been done regarding rotational effects. The present study attempts to fill this void. Specifically, the objectives of this study are: (a) to create and analyze finite element models for harmonic forced response vibration analysis coupled with shunted piezoelectric circuits for engine blade operational conditions, (b) to validate the experimental test approaches with numerical results and vice versa, and (c) to establish a numerical modeling capability for vibration control using shunted piezoelectric circuits under rotation. Study has focused on a resonant damping control using shunted piezoelectric patches on plate specimens. Tests and analyses were performed for both non-spinning and spinning conditions. The finite element (FE) shunted piezoelectric circuit damping simulations were performed using the ANSYS Multiphysics code for the resistive and inductive circuit piezoelectric simulations of both conditions. The FE results showed a good correlation with experimental test results. Tests and analyses of shunted piezoelectric damping control, demonstrating with plate specimens, show a great potential to reduce blade vibrations under centrifugal loading.

Use of the proGAV shunt valve in normal-pressure hydrocephalus.

PubMed

Toma, Ahmed K; Tarnaris, Andrew; Kitchen, Neil D; Watkins, Laurence D

2011-06-01

Overdrainage is a common complication associated with shunt insertion in normal-pressure hydrocephalus (NPH) patients. Using adjustable valves with antigravity devices has been shown to reduce its incidence. The optimal starting setting of an adjustable shunt valve in NPH is debatable. To audit our single-center practice of setting adjustable valves. We performed a retrospective review of clinical records of all NPH patients treated in our unit between 2006 and 2009 by the insertion of shunts with a proGAV valve, recording demographic and clinical data, shunt complications, and revision rates. Radiological reports of postoperative follow-up computed tomography scans of the brain were reviewed for detected subdural hematomas. A proGAV adjustable valve was inserted in 50 probable NPH patients between July 2006 and November 2009. Mean ± SD age was 76 ± 7 years. Mean follow-up was 15 months. The initial shunt setting was 6 ± 3 cm H2O, and the final setting was 4.9 ± 1.9 cm H2O. Nineteen patients required 24 readjustment procedures (readjustment rate, 38%; readjustment number, 0.48 times per patient). One patient (2%) developed delayed bilateral subdural hematoma after readjustment of his shunt valve setting as an outpatient. Starting with a low opening pressure setting on a proGAV adjustable shunt valve does not increase the chances of overdrainage complications and reduces the need for repeated readjustments.

[A case of non-traumatic tension pneumocephalus 12 years after initial ventriculo-peritoneal shunt].

PubMed

Idei, Masaru; Yamane, Kanji; Okita, Shinji; Kumano, Kiyoshi; Nakae, Ryuta; Nishizawa, Shigeru

2009-10-01

The authors presented a patient with non-traumatic tension pneumocephalus 12 years after initial ventriculo-peritoneal shunt. A 60-year-old man had a past history of subarachnoid hemorrhage. At ÿtime, he underwent clipping surgery and emplacement of a ventriculoperitoneal shunt with a low pressure valve, and was discharged from hospital in a bedridden condition. After 12 years, he was transferred to our hospital because of dysarthria and right hemiparesis. On admission, he had multiple dimples of the scalp in the left frontal area where craniotomy had been carried out 12 years before. Head CT scan revealed air located mainly in bilateral subdural space and collapsed ventricles. We suspected that he had a tension pneumocephalus through a scalp-subdural fistula induced by long-term low intracranial pressure. Operation for closure of the fistula was intended. During the operation a subdural abscess was found so, artificial bone and the shunt system was removed. We were able to detect the fistula from the defect of the scalp to the subdural space and closed it by repairing a scalp defect, using dural plasty. Postoperative clinical course was uneventful and the patient was discharged. About 6 month after the operation, cranioplasty and lumbo-peritoneal shunt was performed. We must recognize that appropriate management of intracranial pressure after installation of a ventriculo-peritoneal shunt is necessary for prevention of tension pneumocephalus.