Portal Shunt Research Articles

Endoscopic Treatment for Portal Hypertension: What’s New in the Last 12 Months?

For some 20 years now, endoscopy has been revolutionizing the management of variceal hemorrhage as the most life-threatening sequela of portal hypertension. Portal shunt procedures and decompressive surgery have largely been replaced by endoscopic treatment modalities. However, endoscopic treatment is still a palliative measure, as it does not alter the underlying portal hypertension. Pharmacotherapy and transjugular intrahepatic portosystemic shunting (TIPS) are therefore still indispensable adjuncts for controlling and preventing variceal hemorrhage. Papers published in this field between June 2003 and August 2004 focusing on endoscopic topics are reviewed here.

Evidence-based evolution of the MELD/PELD liver allocation policy

Evidence-based evolution of the MELD/PELD liver allocation policy

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

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. 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< or =10%; group II, 10%<PSI<30%; and group III, 30%< or =PSI. Of these, selected 122 Child-Pugh stage A (Child A) subjects were included in analysis (a mean follow-up period of 5.9+/-5.4 years, range 6 mo-21 years). No significant correlation between PSI and cumulative probability of HCC incidence was observed. Cumulative probability of Child A to B progression was tended to be higher in group III than in group I, and significantly higher in group III than in group II (62% vs 34%, 62% vs 37%; P = 0.060, <0.01; respectively). Cumulative probability of varices tended to be higher in group III than in group I (31% vs 12%, P = 0.090). On multivariate analyses, significant correlation between PSI and Child A to B progression was observed, and no significant correlation between PSI and HCC incidence or varices progression was observed. Patients with LC-C of Child A will progress to Child B rapidly after their PSI reaches 30% or higher. PSI can be used to predict occult progressive 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.

Augmentation de la perméabilité à long terme des anastomoses porto-caves par voie transjugulaire (TIPS) chez 218 patients cirrhotiques, grâce à un suivi strict

To measure the impact of strict monitoring on long term permeability of TIPS. From November 1991 to December 2002, 208 patients (152 men and 66 women managed for the placing of a TIPS following failure with sclerotherapy or refractory ascites were included. The permeability of the prosthesis was controlled on the surgical piece. Revision of the TIPS was performed at the same time as the diagnosis of obstruction using trans-jugular angiography. The TIPS permeability was classified into 3 categories: primary permeability (duration of permeability recorded up until any intervention); assisted primary permeability (duration of continuous permeability with or without percutaneous intervention); secondary permeability (total duration of permeability with or without treated occlusion). Among the 218 patients in the study, 108 had been monitored for less than one year (49.5%), 29 for between 1 and 2 years (13.5%), 27 between 2 and 3 years (12.5%), 16 between 3 and 4 years (7.5%), 15 between 4 and 5 years (7%) and 23 for more than 5 years (10%). The mean follow-up period was of 24.1 +/- 27.2 months (median: 13.7). Current survival of these patients was of 81.2 +/- 2.9% at 1 year, 62.9 +/- 4.2% at 3 years and 52 +/- 4.9% at 5 years. Thirty-four patients were lost to follow-up (16%), after a mean follow-up of 22.9 +/- 26.7 months (median: 9.7). All these patients exhibited a permeable TIPS during their last control. One hundred and thirty-five patients (62%) had never presented obstruction of the TIPS, with a mean follow-up of 19.5 +/- 26.2 months (median: 7.4); 83 patients (38%) exhibited 117 episodes of obstruction; 24 two episodes, 7 three and 3 more than three; 4 exhibited thrombosis provoked by an invalidating encephalopathy and contraindicating transplantation, 2 of them following a first episode of thrombosis. The current primary, primary assisted and secondary permeability rates were respectively: 67.7 +/- 3 and 514 +/- 3.7%, 79.9 +/- 2.3% and 69.3 +/- 3.4%, 94.4 +/- 1.8% and 91 +/- 2.6% at 1 and 3 years (p = 0.0001, Log Rank = 65.3). Univariate analysis revealed a relationship between the onset of an episode of early or late obstruction and the patients' age at the time the TIPS was inserted, Child's score before, and the pre- and post-surgical gradient. In multivariate analysis, none of these elements reached significance. Although the use of TIPS in the treatment of portal hypertension follows the course of development of all surgery towards minimally invasive methods, it should not be considered as a surgical portal shunt or as a permanent treatment: long-term permeability is only obtained with strict and regular monitoring and the possibility of rapid intervention in the case of obstruction.

A CASE OF NON-CIRRHOTIC PORTAL-SYSTEMIC ENCEPHALOPATHY TREATED BY COIL EMBOLIZATION OF THE PORTASYSTEMIC SHUNT

Introduction: Intrahepatic portal-systemic venous shunts are defined as communication between the portal and the systemic venous circulation, measuring more than 1mm in diameter, and at least partially located inside the liver. The cause of this condition is disputed in many cases. It may be congenital or acquired secondary to portal hypertension. Here we describe a case of portal-systemic encephalopathy due to a spontaneous large-caliber portal-hepatic venous shunt. The encephalopathy was corrected with the treatment of the shunt. Case presentation: A 72-year-old man presented with recurrent episodes of change in mental status. His past medical history was unremarkable without history of hepatitis or cirrhosis. No history of trauma. Liver function was normal except for an elevated ammonia level. Hepatitis panel was negative. AMA, ANA and ASMA were all within normal limits. Abdominal ultra-sonography showed a large caliber portal-hepatic venous shunt in the posterior right lobe. Percutaneous transhepatic portography and hepatic venous angiogram were confirmatory. The treatment with coil embolization was successful, and his encephalopathy resolved postoperatively. Patient has been doing fine on one year follow up without recurrence of his encephalopathy. Discussion: A large intrahepatic portal-hepatic venous shunt is a rare condition. Most of the cases are primary as a congenital fistula or secondary to blunt trauma, hepatic tumor or liver biopsy. Spontaneous portal-hepatic shunt is very rare especially in non-cirrhotic patients. Most of these are asymptomatic discovered incidentally during imaging study done for not related causes. Few cases of portal hypertension had been reported secondary to intrahepatic portal shunt. Non-cirrhotic intrahepatic portal hypertension is difficult to evaluate. Encephalopathy secondary to porto-systemic shunt is seen mostly in patients with concomitant cirrhosis. The dramatic improvement of this patient's encephalopathy after the embolization of the shunt indicate that his encephalopathy was related at least in part to the shunt. Possibilities for treatment of such condition include embolization by interventional radiologist or surgery. The etiology of the shunt in this patient is unclear. Given the age of the patients and the absence of history of cirrhosis ortrauma, the shunt is thought to be spontaneous.

Diagnostic value of 16 slices spiral-CT for portal vein disorders.

The diagnostic value of 16-slices spiral computed tomography (CT) for portal vein disorders was evaluated. Forty-one patients were scanned by the 16-slices spiral-CT. The celiac trunk, portal vein and their branches were reconstructed by volume rendering (VR), multiplanar volume reconstruction (MPVR) and maximum intensity projection (MIP) technique, and the results were compared with digital subtraction angiography (DSA). VR, MPVR and MIP could display celiac trunk, portal vein, inferior vena cava and their branches and extent of portal vein-vena cava shunt, portal vein emboli and the fistula of hepatic artery-portal vein. The results from 16-slices CT were better than DSA and identical with pathologic ones. The vessel three-dimension reconstruction technique of 16-slices spiral CT is valuable for evaluating the portal systemic disorders.

Placement of Transjugular Intrahepatic Portosystemic Shunt Via the Left Hepatic Vein under Sonographic Guidance in a Patient with Right Hemihepatectomy

In a patient with refractory ascites after right hemihepatectomy TIPS was created between the left hepatic vein and the left portal vein via a transjugular approach. The puncture was guided only by sonography from the epigastrium. Portosystemic pressure gradient was reduced from 28 to 7 mm Hg and ascites disappeared. This case shows that TIPS can be created with technical and clinical success after right hemihepatectomy as left hepatic vein to left portal vein shunt under sonographic guidance.

Surgical technique and clinical outcome of mesenterico left portal shunt after pediatric liver transplantation

Surgical technique and clinical outcome of mesenterico left portal shunt after pediatric liver transplantation

Locomotor Activity and Temperature Rhythms in Cirrhotic and Portal Hypertensive Rats

This study was performed to examine the circadian variations in body temperature and locomotor activity in two rat models of liver damage and portal-systemic collateralization, it is, cirrhosis by common bile duct ligature and portal vein ligation. Locomotor activity and temperature were measured telemetrically, and the degree of portal-systemic shunting was evaluated by the radioactive microsphere technique. In cirrhotic rats a significant increase in portal pressure and portal-systemic shunting occurred, with extensive liver damage and ascitis. These changes were accompanied by a derangement of the activity rhythm (decrease in total activity, night/day ratio and Qp) and an increase in the amplitude of the temperature rhythm. In portal vein-ligated rats, portal vein pressure and portal-systemic shunting increased significantly, with no changes in any of the rhythm parameters analyzed (total, diurnal and nocturnal activity pulses, night/day activity ratio and Qp for activity; mesor, amplitude and free-running period for temperature). The results indicate that liver dysfunction, and not merely portal hypertension or portal-systemic shunting, is the main factor affecting daily rhythms in cirrhotic rats.

Percutaneous inferior vena cava-to-portal vein shunt (PIPS) using a stent-graft: preliminary results.

To present preliminary results of an inferior vena cava (IVC)-to-portal vein shunt (PIPS) that is created through the caudate lobe of the liver. Sixteen patients (13 men; mean age 50 years, range 32-63) were referred for PIPS procedures because of bleeding varices (n = 11), intractable ascites (n = 4), and hepatorenal syndrome (n = 1). The severity of liver disease was Child's B in 2 and Child's C in 14. The PIPS was created by a transhepatic puncture through the IVC and the portal vein; an endograft made of polytetrafluoroethylene sutured to a Palmaz stent was placed through a jugular approach. In 13 (81%) patients, the portal vein-to-IVC tracts were successfully created. The postprocedural portal vein-IVC gradients varied from 1 to 9 mm Hg (mean 5). There were 2 deaths in the 30-day periprocedural period from adult respiratory distress syndrome and hepatorenal syndrome. A third patient died at 31 days from liver failure owing to continuing alcohol abuse. In addition, there was 1 case of peritoneal bleeding treated with blood product replacement. The follow-up period ranged from 14 to 671 days (mean 343). None of the patients treated for variceal bleeding had another bleeding episode, but 2 patients who had a PIPS procedure for refractory ascites did not benefit from the procedure. Postprocedure, 46% (6/13) of the patients had hepatic encephalopathy, which was unchanged from baseline. The primary and secondary patency rates at 365 days were 60% and 65%, respectively. The preliminary results using a stent-graft to create an IVC-portal vein shunt are encouraging and support further work to better determine the role of this procedure.

The effects of portal shunts on intestinal cytochrome P450 3A activity

The effects of portal shunts on intestinal cytochrome P450 3A activity

Hepatic arterial perfusion decreases intrahepatic shunting and maintains glucose uptake in the rat liver.

Intrahepatic shunts have an important function in the regulation of portal venous pressure in the normal rat liver. The present study determined their location, the region of confluence between the hepatic arterial and portal venous vasculatures, regions within the liver that are bypassed and the effects of hepatic arterial perfusion upon the intrahepatic redistribution of portal venous flow. Livers of male Sprague-Dawley rats were excised and perfused in vitro. Hepatic bromosulphthalein (BSP) and glucose uptake were measured in hepatic venous samples. Diversion of the hepatic arterial supply into the portal venous vasculature opened the portal venous intrahepatic shunts and resulted in a 50% reduction in portal venous glucose uptake from 29.6+/-1.6% to 14.9+/-0.9% ( P<0.0001 Student's paired t-test). Portal venous injection of 15-microm-diameter microspheres also opened the intrahepatic shunts and reduced portal venous glucose uptake to 10% from 29.0+/-1.6% to 7.8+/-0.9% ( P<0.0001 Student's paired t-test). No significant reductions in portal venous BSP uptake (43.0+/-6.9 to 48.0+/-4.8%) or hepatic arterial glucose uptake, from an average value of 94.0%, occurred. Therefore, cessation of hepatic arterial perfusion or portal venous injection of microspheres reduced portal venous glucose uptake without affecting BSP uptake. It is concluded that intrahepatic shunts divert perfusate away from the perivenous, sinusoidal (zone III) regions and into the hepatic venous vasculature, distal to zone III. The microsphere data indicate that confluence between the hepatic arterial and portal venous vasculatures occurs mainly in sinusoidal zone II.

Hepatic arterial perfusion regulates portal venous flow between hepatic sinusoids and intrahepatic shunts in the normal rat liver in vitro.

Intrahepatic shunts regulate portal venous pressure during periods of acute portal hypertension when the transhepatic portal resistance is momentarily increased in the normal rat liver in vivo. Hepatic arterial inflow may also increase the transhepatic portal resistance and activate intrahepatic shunts. In the present study, the transhepatic portal resistance and the activity of intra-hepatic shunts were measured in vitro and the point of confluence between the hepatic artery and portal vein in the rat determined. Livers of male Sprague-Dawley rats were single-pass, dual-perfused in vitro. Total cessation or diversion of the hepatic arterial inflow to the portal venous vasculature, whilst maintaining total hepatic perfusate flow, decreased intrasinusoidal pressure, increased transhepatic portal venous resistance and opened the portal venous intrahepatic shunts in a manner similar to intraportal injection of 15-microm diameter microspheres. Injections of the microspheres into the hepatic arterial circulation increased hepatic arterial pressure dramatically, consistent with complete occlusion of the arterial vasculature. The intrahepatic shunts are located at a pre-sinusoidal level because no increases were detected in hepatic arterial pressure following intraportal injection of microspheres. The hepatic arterial vasculature, unlike the portal supply, does not possess a collateral shunt circulation and coalesces with the portal vein at an intrasinusoidal location

SPONTANEOUS SHUNT BETWEEN THE SUPERIOR MESENTERIC VEIN AND THE RIGHT RENAL VEIN CAUSED BY PORTAL HYPERTENSION

Although abnormal communication between the splenic vein and left renal vein is a common finding in portal hypertension, spontaneous portal and right renal vein shunt is extremely rare. To our knowledge only 1 case of a main portal vein to a right renal vein collateral diagnosed by color Doppler ultrasonography has been reported. We report a case of spontaneous shunt between the superior mesenteric vein and the right renal vein caused by portal hypertension.

Budd-Chiari syndrome: current management options.

To assess the outcomes of current treatment strategies for Budd-Chiari syndrome. Budd-Chiari syndrome, occlusion or obstruction of hepatic venous outflow, is a disease traditionally managed by portal or mesenteric-systemic shunting. The development of other treatment options, such as catheter-directed thrombolysis, transjugular portosystemic shunting (TIPS), and liver transplantation, has expanded the therapeutic algorithm. The authors reviewed the medical records of all patients diagnosed with Budd-Chiari syndrome at the Johns Hopkins Hospital during the past 20 years. A total of 54 patients were identified: 13 (24%) male patients and 41 (76%) female patients, ranging in age from 2 to 76 years (median 33 years). Twenty-one (39%) had polycythemia vera, 3 (5.6%) used estrogens, 11 (20%) had a myeloproliferative or coagulation disorder, and in 7 (13%) the cause remained unknown. Forty-three patients were treated with surgical shunting, 24 mesocaval and 19 mesoatrial. Actuarial survival rates at 1, 3, and 5 years after shunting were 83%, 78%, and 75%, respectively. Of 33 patients surviving more than 4 years, 28 (85%) had relief of clinical symptoms. Five patients required shunt revision and eight had radiologic procedures to maintain shunt patency. Primary and secondary shunt patency rates were 46% and 69% respectively for mesoatrial shunts and 70% and 85% respectively for mesocaval shunts. Clot lysis was successful as primary treatment in seven patients. TIPS was performed in three patients, one after a failed mesocaval shunt. During an average of 4 years of follow-up, these patients required multiple procedures to maintain TIPS patency. Six patients underwent liver transplantation. Of these, three had previous shunt procedures. Five of the transplant recipients are alive with follow-up of 2 to 9 years (median 6). Both shunting and transplantation can result in a 5-year survival rate of at least 75%, and other treatment modalities may be appropriate for highly selected patients. Optimal management requires that treatment be directed by the predominant clinical symptom (liver failure or portal hypertension) and anatomical considerations and be tempered by careful assessment of surgical risk.

Portal mesenteric shunting for reconstruction of the visceral venous system

Reconstruction of the mesenteric venous system, particularly during pancreaticoduodenectomy, is a formidable procedure. The trend of increasing the extent of resections to encompass the portal– superior mesenteric venous system with tumor adherence or ingrowth is being performed with increasing frequency worldwide. 1,2 This article was prompted by our use of a modified shunting technique to perform mesenteric venous reconstruction, preventing visceral congestion and permitting hepatic perfusion during most of the time period required for this component of a pancreaticoduodenectomy. Recent large series of pancreatic resections have reported no instances of using shunts.

Portal shunt index: An indicator for assessing the efficacy of propranolol as a secondary prophylaxis for esophageal variceal bleeding

Portal shunt index: An indicator for assessing the efficacy of propranolol as a secondary prophylaxis for esophageal variceal bleeding

Clinical need for both scintigraphy with technetium-99m GSA and per-rectal portal scintigraphy in some patients with chronic liver disease.

Scintigraphy with 99mTc-diethylenetriaminepentaacetate with galactosyl human serum albumin (99mTc-GSA) and per-rectal portal scintigraphy are useful for evaluating hepatic functional reserve and portal circulation, respectively. We did the procedures simultaneously in some patients to examine the relationship between hepatic functional reserve and portal circulation in chronic liver disease. Scintigraphy with 99mTc-GSA was done in 10 healthy subjects, 45 patients with chronic hepatitis, and 165 patients with cirrhosis. Fifty-seven patients (13 with hepatitis and 44 with cirrhosis) also underwent per-rectal portal scintigraphy with 99mTc-pertechnetate within two weeks. A receptor index was calculated by dividing the radioactivity of the liver region of interest (ROI) by that of the liver-plus-heart ROI at 15 min after the injection of 99mTc-GSA. The index of blood clearance was calculated by dividing the radioactivity of the heart ROI at 15 min by that of the heart ROI at 3 min. A solution containing 99mTc-pertechnetate was instilled into the rectum, and serial scintigrams were taken while radioactivity curves for the liver and heart were recorded sequentially. A per-rectal portal shunt index was determined by calculating the ratio of counts for the liver to counts for the heart integrated for 24 seconds immediately after the appearance of the liver time-activity curve. The median receptor index was lower for more severe liver disorders, increasing in the order of chronic hepatitis, compensated cirrhosis and decompensated cirrhosis, and the median index of blood clearance was higher. The median receptor index was significantly lower when a complication (varices, ascites, or encephalopathy) was present, and the median index of blood clearance was higher. The shunt index was correlated significantly with the two other indices, but these values for some one-third of the patients disagreed in either indices. Scintigraphy with 99mTc-GSA and per-rectal portal scintigraphy with 99mTc-pertechnetate are both needed for accurate assessment of the severity of chronic liver disease before treatment-making decisions, because in some patients, results are not correlated.

Surgical technique for inferior mesenteric vein to renal vein shunt in portal hypertension

An important role still exists for the creation of surgical portasystemic shunts. Multiple techniques have been described. However, no particular one is satisfactory for all clinical situations. The objective of the present paper is to describe an alternative surgical technique for the creation of a decompressive portasystemic shunt. This technique consists of an end-to-side anastomosis between the inferior mesenteric vein and the left renal vein. In our experience, the inferior mesenteric vein to left renal vein anastomosis may be a useful portal decompressive shunt for patients with otherwise difficult peri-portal or peri-pancreatic anatomic exposures. This technique should be a useful tool in the armamentarium of surgeons dealing with patients who need portal decompressive surgical shunts.

Liver Ischemia Modifies the Concentration of Plasmatic Catecholamines after Reperfusion in the Rat

Pulmonary hypertension is one of the most frequent and severe consequences of liver ischemia. The aim of this study is to evaluate the presence of humoral vasoactive mediators, generated during liver ischemia, which could be able to determine the onset of pulmonary hypertension. Thus, we evaluated the plasmatic concentration of catecholamines (adrenaline, noradrenaline, dopamine) during the immediate reperfusion period. Wistar rats were used. Animals (n = 89) were divided into four groups. Group 1 served as control (sham-operated). In group 2 animals underwent 60 min of left hepatic exclusion. In group 3 animals underwent to bilateral adrenectomy. In group 4 animals had both bilateral adrenectomy and liver ischemia. Ischemia in group 2 and 4 was induced by interrupting the vascular supply to the left and median lobes, so avoiding the use of a portal shunt. Blood samples were collected from the suprahepatic inferior caval vein immediately after reperfusion. Strips of the main pulmonary artery were put into an isolated organ bath and tested for the response to noradrenaline, adrenaline and plasma samples. Plasma samples collected after ischemia caused a significantly greater (p < 0.01) contraction of the pulmonary artery compared to controls. Plasma samples collected after adrenectomy caused a weak contraction which was not different from that obtained in the adrenectomy + ischemia group. Plasma concentrations of catecholamines after liver ischemia were significantly increased in the control group (p < 0.01). In adrenectomized rats only the adrenaline level was greatly reduced. However ischemia did not increase plasma catecholamines as it occurred in sham-operated rats.