Large Portosystemic Shunt Research Articles

巨大門脈大循環シャントによる猪瀬型肝性脳症に対し外科的シャント閉鎖を行った1例

巨大門脈大循環シャントによる猪瀬型肝性脳症に対し外科的シャント閉鎖を行った1例

Prognostic assessment in patients with hepatic encephalopathy.

Hepatic encephalopathy (HE) is a common complication of liver failure that is associated with poor prognosis. However, the prognosis is not uniform and depends on the underlying liver disease. Acute liver failure is an uncommon cause of HE that carries bad prognosis but is potentially reversible. There are several prognostic systems that have been specifically developed for selecting patients for liver transplantation. In patients with cirrhosis the prognosis of the episode of HE is usually dictated by the underlying precipitating factor. Acute-on-chronic liver failure is the most severe form of decompensation of cirrhosis, the prognosis depends on the number of associated organ failures. Patients with cirrhosis that have experienced an episode of HE should be considered candidates for liver transplant. The selection depends on the underlying liver function assessed by the Model for End-stage Liver Disease (MELD) index. There is a subgroup that exhibits low MELD and recurrent HE, usually due to the coexistence of large portosystemic shunts. The recurrence of HE is more common in patients that develop progressive deterioration of liver function and hyponatremia. The bouts of HE may cause sequels that have been shown to persist after liver transplant.

Prognostic Assessment in Patients with Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a common complication of liver failure that is associated with poor prognosis. However, the prognosis is not uniform and depends on the underlying liver disease. Acute liver failure is an uncommon cause of HE that carries bad prognosis but is potentially reversible. There are several prognostic systems that have been specifically developed for selecting patients for liver transplantation. In patients with cirrhosis the prognosis of the episode of HE is usually dictated by the underlying precipitating factor. Acute-on-chronic liver failure is the most severe form of decompensation of cirrhosis, the prognosis depends on the number of associated organ failures. Patients with cirrhosis that have experienced an episode of HE should be considered candidates for liver transplant. The selection depends on the underlying liver function assessed by the Model for End-stage Liver Disease (MELD) index. There is a subgroup that exhibits low MELD and recurrent HE, usually due to the coexistence of large portosystemic shunts. The recurrence of HE is more common in patients that develop progressive deterioration of liver function and hyponatremia. The bouts of HE may cause sequels that have been shown to persist after liver transplant.

MR Evaluation of Portal Hypertensive Collateral Shunting Vessels for Predicting Outcome after Transjugular Intrahepatic Portosystemic Shunt

We assessed whether magnetic resonance (MR) imaging evaluation of portosystemic collateral shunts can aid prediction of therapeutic effectiveness and complications after creation of a transjugular portosystemic shunt (TIPS), and technical difficulty during the TIPS procedure. We retrospectively reviewed 32 patients (27 men, 5 women; mean age, 56.4 years) who underwent TIPS creation following gadolinium-enhanced MR examination. We measured the diameters of pre-existing portosystemic collateral shunting vessels, added the measurements together to generate a shunting collateral score for each patient, and divided patients into 2 groups by score of 4 or greater or less than 4. We then compared therapeutic effectiveness, technical difficulty and complications of the TIPS procedure, and portal venous (PV) pressure, PV-inferior vena cava (IVC) pressure gradient, and PV diameter between the groups. The patients with a pre-existing large portosystemic shunt showed insignificant trends toward higher technical difficulty of the shunt procedure and rate of shunt dysfunction. The 2 groups showed no significant difference in early mortality rate, onset or worsening rate of hepatic encephalopathy after TIPS creation, PV pressure, PV-IVC pressure gradient, or PV diameter. Gadolinium-enhanced MR imaging may help in predicting technical difficulty and complications of TIPS.

Long‐term results of balloon‐occluded retrograde transvenous obliteration for gastric fundal varices: Hepatic deterioration links to portosystemic shunt syndrome

It is well known that a large portosystemic shunt develops during portal hypertension. In this study, we studied the long-term effects of a large splenorenal shunt (SRS) on liver function and survival. The subjects were divided into three groups: an SRS (-) group consisting of cirrhotic patients without SRS; an SRS (+) group consisting of patients with gastric fundal varices and SRS; and a balloon-occluded retrograde transvenous obliteration (B-RTO) group with a completely obliterated SRS by B-RTO. We compared the following among these groups: the total bilirubin levels, serum albumin levels, prothrombin times, changes in Child-Pugh scores, and survival rates. After a 3-year follow-up period the Child-Pugh scores showed significant differences among the SRS (+), SRS (-), and B-RTO groups. The score worsened for the SRS (+) group. The cumulative survival rates were significantly different between the SRS (+) and SRS (-) groups and between the SRS (+) and B-RTO groups. The vital prognosis worsened for the SRS (+) group. The presence of a large splenorenal shunt (portosystemic shunt) was indicated to lower liver function and vital prognosis. B-RTO, which completely obliterates large splenorenal shunts, inhibited the lowering of hepatic functional reserve and the worsening of vital prognosis, indicating a protective role. Liver pathology and the presence of a large portosystemic shunt each separately result in progressive liver dysfunction and worsen the survival rate. We found that such a pathological condition had occurred due to a large portosystemic shunt, and it should be called 'portosystemic shunt syndrome.'

186 PORTAL VEIN THROMBOSIS IN CIRRHOTIC PATIENTS: SAFETY AND EFFICACY OF LOW DOSAGE OF ENOXAPARIN

Introduction: Cognitive deficits in cirrhotics, also known as MHE, may have important implications being associated to reduced quality of life and driving capacity. Moreover, patients with MHE are at risk of developing OHE. However, in practice the presence of MHE is seldom searched due to lack of standardized technique. The Psychometric Hepatic Encephalopathy Score (PHES), which includes Digit-Symbol-Test (DST), Trail-Making-TestA, Trail-Making-TestB, Serial-Dotting-Test (SDT) and Line-Tracing-Test (LTT) is considered the gold standard. Aims of the study: 1. simplify the PHES 2. establish if any correlation exists between PHES or simplified PHES (SPHES) and development of HE. Patients and Methods: 79 consecutive cirrhotic patients, (M/F49/30, 60±13yrs, ChildClass A/B/C 33/31/15, MELD-score 14±6) were studied. 20 patients showed large varices at endoscopy and 6 were TIPS carriers. All patients were examined according to PHES: in 45 MHE was diagnosed. The results of each psychometric test ware expressed as z-scores of an Italian population standardized for age and education. In order to simplify the evaluation of MHE, a backward logistic regression analysis was performed incorporating at the first step the z-scores of the 5 tests included in PHES, and stepwise eliminating variables whose removal did not impair the regression. Results: Logistic analysis showed that a model containing DST, SDT, and LLT was not significantly different from that containing the whole set of 5 variables (Table). Rate of patients correctly classified did not change significantly (94%). 20/79 patients developed an episode of OHE during FU. The probability of developing OHE was significantly higher in MHE+ than in MHE− patients identified either according to PHES (p =0.012) or SPHES (p =0.019). At a Cox’s analysis including Child– Pugh class, MELD-score and the presence of large porto-systemic shunt, either PHES (RR3.75, p = 0.03) or SPHES (RR3.17, p = 0.04) were associated to OHE during follow-up. Conclusions: A simplified battery of psychometric tests including DS, SDT and LTT (SPHES) does not impair the diagnostic ability of the whole PHES, and correlates with the development of OHE as well as PHES. Both SPHES and PHES are independent factors for the occurrence of OHE. SPHES deserves further validation in an independent group of patients.

Congenital extrahepatic portosystemic shunt associated with heterotaxy and polysplenia

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

ACQUIRED PORTAL COLLATERAL CIRCULATION IN THE DOG AND CAT

We describe patterns of acquired portal collateral circulation in dogs and in a cat using multidetector row computed tomography angiography. Large portosystemic shunts included left splenogonadal shunts in patients with portal hypertension. Small portal collaterals were termed varices; these collaterals had several patterns and were related either to portal vein or cranial vena cava obstruction. Varices were systematized on the basis of the venous drainage pathways and their anatomic location, namely left gastric vein varix, esophageal and paraesophageal varices, gastroesophageal and gastrophrenic varices, gallbladder and choledocal varices, omental varices, duodenal varices, colic varices, and abdominal wall varices. As reported in humans and in experimental dog models, esophageal and paraesophageal varices may result from portal hypertension that generates reversal of flow, which diverts venous blood in a cranial direction through the left gastric vein to the venous plexus of the esophagus. Blood enters the central venous system through the cranial vena cava. Obstructions of the cranial vena cava can lead to esophageal and paraesophageal varices formation as well. In this instance, they drain into the azygos vein, the caudal vena cava, or into the portal system, depending on the site of the obstruction. Gallbladder and choledocal varices, omental varices, duodenal varices, phrenico-abdominal varices, colic varices, abdominal wall varices drain into the caudal vena cava and result from portal hypertension. Imaging plays a pivotal role in determining the origin, course, and termination of these vessels, and the underlying causes of these collaterals as well. Knowledge about these collateral vessels is important before interventional procedures, endosurgery or conventional surgery are performed, so as to avoid uncontrollable bleeding if they are inadvertently disrupted.

Atypical Manifestation of Patent Ductus Venosus in a Child: Intervening against a Paradoxical Presentation

A 6-year-old boy with massive gastrointestinal bleeding was found to have a large patent ductus venosus (PDV). Systemic symptoms of PDV (eg, hypergalactosemia and hepatic, pulmonary, and cardiac dysfunction) are frequent. However, gastrointestinal bleeding with the presence of a large portosystemic shunt is not a known complication of this anomaly. The shunt was successfully treated with embolization by using the Amplatzer vascular plug, with immediate cessation of bleeding. The authors propose that relative ischemia of the bowel, rather than portal hypertension, was the cause of the gastrointestinal bleeding in this child.

Hepatic encephalopathy after liver transplantation in a patient with a normally functioning graft: Treatment with embolization of portosystemic collaterals

Received April 5, 2008; accepted May 11, 2008.Portosystemic encephalopathy is one of the most im-portant complications of liver cirrhosis. The restorationof normal hepatic function and the reduction of porto-systemic shunts by means of a liver graft are followedby the resolution of hepatic encephalopathy. We reportthe case of a patient with a normal functioning graftthat developed recurrent encephalopathy after trans-plantation. The patient was successfully treated by em-bolization of a large portosystemic shunt between thesuperior mesenteric vein and both gonadal veins, thiscausing an inversion of the superior mesenteric veinflow.

Concomitant Hepatic Encephalopathy and Refractory Ascites: Successful Treatment with Staged Embolization of Two Large Portosystemic Shunts and Transjugular Intrahepatic Portosystemic Shunt Placement

A patient with cirrhosis, refractory ascites, and two large competitive portosystemic shunts presented with uncontrollable acute exacerbation of chronic hepatic encephalopathy (HE). A staged procedure was performed by first performing embolization of a large mesogonadal shunt to treat the HE. Three months later, a transjugular intrahepatic portosystemic shunt (TIPS) was created to address the ascites. A large paraumbilical vein shunt was embolized at TIPS placement to minimize the risk of recurrent HE. At 9-month follow-up, the ascites was well controlled with medical management with little or no HE.

Enhancement of the liver on dynamic MDCT: investigation among three groups consisting of noncirrhotic patients and cirrhotic patients with and without a large portosystemic shunt

The aim of this study was to determine any difference in hepatic enhancement values on dynamic multidetector row computed tomography (MDCT) among three groups: noncirrhotic patients and cirrhotic patients with and without a large portosystemic shunt. A group of 20 noncirrhotic patients (group A), 43 cirrhotic patients without a large shunt (group B), and 20 cirrhotic patients with a large shunt (group C) underwent dynamic MDCT of the liver using a standard concentration (300 mg I/ml) and volume (100 ml) of contrast material. The attenuation values of the liver were measured during arterial, portal, and late phases. The hepatic enhancement value during the portal phase was significantly higher in group A (56.2 +/- 13.7 HU) than in the other two groups (group B 39.8 +/- 11.9 HU, group C 41.3 +/- 8.3 HU) (P < 0.01). No significant difference was present between group B and group C. The regression line of the scattergram, which shows the relation between the hepatic enhancement value during the portal phase and the iodine dose per the patients' body weight was more gently sloping in group C than in the other two groups. In cirrhotic patients without a large shunt, injection of a larger amount of total iodine is necessary to optimize hypovascular tumor visualization. However, in cirrhotic patients with a large shunt, further investigation is needed concerning the effectiveness of administering a larger amount of total iodine.

Triple-phase computed tomography and intraoperative flow measurements improve the management of portosystemic shunts during liver transplantation

Ligation of portosystemic shunts in patients with cirrhosis undergoing liver transplantation has been recommended to avoid insufficient portal vein (PV) flow. Shunts are not always recognized pretransplantation because intraoperative PV flow assessment is not routinely attempted. As a result of a posttransplantation PV thrombosis in a recipient with a large portosystemic shunt and a PV flow <1 L/minute, we employed triple-phase computed tomography with vascular reconstruction and intraoperative graft flow measurement to determine the need for inflow modification in our next 16 patients with large portosystemic shunts. Subsequently, 6 patients with large portosystemic shunts and PV flows <or=1 L/minute underwent inflow modification at the time of transplantation to improve venous graft inflow. One patient with PV thrombosis had PV replacement without shunt ligation. Two patients with large splenorenal shunts and extensive PV thrombosis had left renoportal bypass. In 7 patients with large portosystemic shunts and PV flow greater than 1 L/minute, inflow modification was not attempted, to avoid excessive venous inflow that could jeopardize hepatic artery flow via the hepatic artery buffer response. In conclusion, sustained good graft function and inflow were achieved in all 16 patients.

Model for end-stage liver disease (MELD) exception for hepatic encephalopathy

Hepatic encephalopathy (HE), a common complication of cirrhosis and end-stage liver disease, has been shown by univariate and multivariate analyses to be a predictor of death in patients with liver failure. The Model for End-Stage Liver Disease (MELD) scoring system does not prioritize patients with HE. The original multivariate analysis leading to the institution of the MELD did not demonstrate that HE increased the model’s ability to predict 3-month pretransplant mortality. Recently, however, data have begun to emerge that point to HE as a predictive factor for short-term mortality and that suggest that the inclusion of HE would improve the predictive ability of the MELD score. An analysis of a model by the Scientific Registry of Transplant Recipients that included HE was strikingly better than MELD at predicting short-term mortality. Said and colleagues recently identified HE as an independent predictor of mortality, and others agree that HE provides additional prognostic information. Despite this, HE remains a subjective diagnosis, and an easily quantifiable and verifiable method for scoring patients is lacking. Recurrent or poorly responsive HE often has an underlying pathophysiology that may be controlled in the setting of otherwise relatively good liver function, such as large spontaneous portosystemic shunts, a proportion of which can be closed; recurrent dehydration, which can be managed by rehydration; sepsis, which can be treated by identifying the underlying cause; and dietary noncompliance, which can be corrected. Cases that are submitted to Regional Review Boards for additional priority because of failure to respond to maximal medical therapy should include clear documentation of patient medication compliance with neomycin, lactulose, sodium benzoate or Buphenyl, rifaximin, and metronidazole. Other conditions for which Regional Review Boards might consider granting additional priority include grade IV hepatic coma requiring hospitalization in an intensive care unit and endotracheal intubation for mechanical ventilation. Cerebral edema associated with HE in the patient with cirrhosis is quickly lethal and may justify an exception if the intracranial pressure is high. Another example is profound HE associated with a large portosystemic shunt that cannot be occluded for technical reasons. Chronic intermittent sepsis in a patient with a low MELD score who has, for example, low-grade prostatitis or breakthrough severe HE requiring hospitalization and airway protection might also justify a MELD exception. To facilitate the development of an accurate method for fair prioritization of liver transplant candidates with HE, we suggest that an estimate of the time spent in (duration of) grade III/IV HE be included in the model. We propose that the West Haven criteria for grading mental status be used to assess for the presence of HE (Table 1). Other, more sophisticated measures need to be studied for their potential use as objective criteria of HE over time. Inclusion of duration of severe HE may identify difficult-to-manage and frequently recurrent HE. The Scientific Registry of Transplant Recipients analysis established that a one-time (cross-sectional) assessment of HE predicts mortality independent of the MELD score. We propose that the strength of this prediction will be greatly enhanced by factoring in duration of severe HE.

Successful Surgical Ligation Under Intraoperative Portal Vein Pressure Monitoring of a Large Portosystemic Shunt Presenting as an Intrapulmonary Shunt: Report of a Case

We report a rare case of patent ductus venosus (PDV) with collapsed intrahepatic portal branches and an intrapulmonary shunt. Excellent improvement of the intrahepatic portal vein flow was achieved by ligating the large ductus venosus under intraoperative portal vein pressure (PVP) monitoring. A 3-year-old boy being followed up for hypergalactosemia at a local hospital was found to have mild lip cyanosis, exertional dyspnea, clubbed fingers, and mild liver dysfunction with high levels of transaminase and ammonia. Cardiac catheterization indicated an intrapulmonary shunt with a ratio of 33%. Abdominal ultrasonography and computed tomography showed remarkable communication between the portal vein and the inferior vena cava. We performed laparotomy and successfully ligated the PDV under PVP monitoring. The PVP did not increase until the catheter was removed 7 days postoperatively. The patient's liver function test results returned to normal within 2 weeks. His serum galactose level was 0 mg/dl after drinking milk, and his SpO2 in room air and exertional dyspnea also improved. He was discharged 18 days after his operation, without any complications. We propose that ligation of a PDV under PVP monitoring could be a treatment of choice, bearing in mind that PDV is associated with collapsed intrahepatic portal branches.

Reversed Intrapulmonary Right-to-Left Shunt After Banding of the Patent Ductus Venosus

Diffuse pulmonary microvascular arteriovenous communication developed in an 8-year-old girl with a patent ductus venosus. Tc-99m macroaggregated albumin (MAA) pulmonary perfusion scintigraphy with total-body imaging demonstrated multiple lung perfusion deficits and abnormal tracer uptake in systemic organs with hepatic radioactivity greater than the kidneys, suggesting the presence of right-to-left shunt and abnormal hepatic hemodynamics. I-123 iodoamphetamine transrectal portal scintigraphy revealed a large portosystemic venous shunt. The follow-up Tc-99m MAA perfusion scans after banding of the patent ductus venosus revealed partial improvement of the perfusion deficits and right-to-left shunt, indicating the possible reversibility of this pulmonary shunt complication.

Congenital absence of the portal vein and role of liver transplantation in children

Background/Purpose: Congenital absence of the portal vein (CAPV) is a subtype of congenital portosystemic shunt, which can cause a broad spectrum of clinical manifestations. The authors report on 4 patients with CAPV including a boy with CAPV-associated encephalopathy, which was resolved effectively by liver transplantation (LT). Methods: The case records of 4 pediatric patients with CAPV who were referred to the author's institution between 1984 and 1999 were reviewed. Results: The patients (3 boys and 1 girl) ranged in age at diagnosis from 0.8 to 14 years. Two patients had growth retardation or disturbed consciousness, and the other 2 had no specific manifestations. Not only high serum levels of bile acids, ammonia, and transaminases but also low plasma levels of branched-chain amino acids were common laboratory findings. The absent portal vein was replaced by a large portosystemic shunt, which connected the splanchnic vein to the inferior vena cava or the left renal vein. Two patients survived without any symptoms, but 1 with growth retardation died of hepatic failure. The other with encephalopathy did not respond to medical therapy and underwent LT, which resolved symptoms and metabolic disorders effectively. Conclusions: Patients with CAPV do not always have a good prognosis. They should be followed up with careful observation of their symptoms, hepatic function, and metabolic abnormalities. LT might be indicated for patients with symptomatic CAPV unresponsive to medical therapy. J Pediatr Surg 36:1026-1031. Copyright © 2001 by W.B. Saunders Company.

Patients with fundal variceal bleeding have frequently large portosystemic shunts which makes them at risk for thrombosis and encephalopathy after tips

European Journal of Gastroenterology & Hepatology: December 1999 - Volume 11 - Issue 12 - p A96

The value of portal vein pulsatility on duplex sonograms as a sign of portal hypertension in children with liver disease.

The purpose of this study was to determine the significance of portal vein pulsatility on duplex Doppler waveforms in children with end-stage hepatic failure undergoing liver transplantation. Thirty-eight children with end-stage hepatic decompensation were examined with color-assisted spectral Doppler waveform analysis of the hepatic artery and the portal vein. Correlation was made with age, duration of illness, clinical and pathologic diagnosis, and presence of portal hypertension. Findings were compared with those for six patients with acute viral hepatitis and 12 healthy control subjects. Portal vein pulsatility was noted in all 36 patients in whom portal vein flow was detected by Doppler imaging. The majority of these (34) had clinical or sonographic evidence of portal hypertension. In two patients, no portal vein flow was identified in the liver hilum; both had a large portosystemic shunt through collaterals or surgical graft. Significantly increased pulsatility of the hepatic artery waveform (resistive index [RI] = 0.89 +/- 0.15, p < .0001) was seen in patients with end-stage liver disease. In contrast, no portal vein pulsatility and normal hepatic artery pulsatility (RI = 0.60 +/- 0.11) was noted in all patients with acute hepatitis and control subjects. Portal vein waveform pulsatility is 94% sensitive and 90% specific for portal hypertension in end-stage liver disease.

Computed tomography in the evaluation of the portal venous system.

Computed tomography has widespread clinical application in the evaluation of the portal venous system, even though quantitative methods are impractical due to the inability to measure portal flow discrete from hepatic arterial flow, morbidity associated with the use of large volumes of iodinated contrast, and technical limitations. This represents a major disadvantage compared to Doppler ultrasound and magnetic resonance angiography. Qualitative applications include evaluation of portal vein patency, diagnosis of portal vein thrombosis, underlying inflammatory or neoplastic conditions, and evaluation of surgically created portosystemic shunts and collateral flow. Diagnostic criteria for portal venous thrombosis include nonopacification of the central portion of the portal vein, peripheral enhancement of the vein, and irregular periportal hepatic parenchymal enhancement. However, misdiagnosis is common, occurring in 16% of cases analyzed in one limited series, and periportal vein enhancement is now recognized as a nonspecific finding associated with underlying endothelial injury. Cavernous transformation of the portal vein and neoplastic invasion of the portal system are more reliably recognized. Computed tomography arterial portography demonstrates collateral pathways and arteriovenous shunts. Computed tomography has a sensitivity of 85% in detection of esophageal varices compared to endoscopy, but has the advantage of demonstrating splenorenal, gastrorenal, peripancreatic, pericholecystic, retroperitoneal and omental collateral vessels, and spontaneous large portosystemic shunts, with greater sensitivity than angiography. Computed tomography combined with Doppler ultrasound angiography remains popular, despite a lack of large-scale prospective efficacy studies demonstrating diagnostic superiority over other imaging techniques, largely because of its accessibility, and its detailed axial anatomic images providing an overview of multiple organ systems, and patency of major vessels.