Extra hepatic portal venous obstruction

Portal hypertension and its management in children

Portal hypertension (PHT), defined as raised intravascular pressure in the portal system, is a complication of chronic liver disease or liver vascular occlusion. Advances in our ability to diagnose and monitor the condition but also predict the risk of gastrointestinal bleeding have enabled us to optimise the management of children with PHT either at a surveillance or at a postbleeding stage. A consensus among paediatric centres in the classification of varices can be beneficial in streamlining future paediatric studies. New invasive (endoscopic and surgical procedures) and non-invasive (pharmacotherapy) techniques are currently used enabling clinicians to reduce mortality and morbidity in children with PHT.

Clinical, radiologic, and endoscopic characteristics upon diagnosis of patients with prehepatic portal hypertension at the Instituto Nacional de Pediatría from 2001 to 2011

BACKGROUND

Prehepatic portal hypertension in children can be asymptomatic for many years. Once diagnosed, the therapeutic measures (pharmacologic, endoscopic, and surgical) are conditioned by the specific characteristics of each patient. In Mexico, there are no recorded data on the incidence of the disease and patient characteristics.

AIMS

To determine the main clinical, radiologic, and endoscopic characteristics upon diagnosis of these patients at the Instituto Nacional de Pediatría within the time frame of January 2001 and December 2011.

METHODS

A cross-sectional, retrolective, descriptive, and observational study was conducted in which all the medical records of the patients with portal hypertension diagnosis were reviewed.

RESULTS

There was a greater prevalence of prehepatic etiology (32/52) (61.5%) in the portal hypertension cases reviewed. Males (62.5%) predominated and 11 of the 32 patients were under 4 years of age. The primary reason for medical consultation was upper digestive tract bleeding with anemia (71.9%) and the main pathology was cavernomatous degeneration of the portal vein (65.6%). Splenoportography was carried out on 17 of the 32 patients. A total of 65.5% of the patients received the combination therapy of propranolol and a proton pump inhibitor. Initial endoscopy revealed esophageal varices in 96.9% of the patients, 12 of whom presented with gastroesophageal varices. Congestive gastropathy was found in 75% of the patients. The varices were ligated in 8 cases, sclerotherapy for esophageal varices was carried out in 5 cases (15.6%), and sclerotherapy for gastric varices was performed in 2 patients. Seventeen patients (53.1%) underwent portosystemic diversion: 10 of the procedures employed a mesocaval shunt and 7 a splenorenal shunt. Nine patients (28.1%) underwent total splenectomy.

CONCLUSIONS

The primary cause of the disease was cavernomatous degeneration of the portal vein; it was predominant in males and the first symptom was variceal bleeding.

Partial splenectomy and use of splenic vein as an autograft for meso-Rex bypass: a clinical observational study

Background

Meso-Rex bypass (MRB) surgery is being increasingly used to treat chronic prehepatic portal hypertension secondary to extrahepatic portal vein thrombosis (EPVT) and cavernous transformation (EPVCT) in children. Rather than using the internal jugular vein (IJV, the traditional venous graft), we used an autogenous splenic vein segment graft for MRB.

Material/Methods

We examined 25 children with extrahepatic portal hypertension and a history of recurrent upper gastrointestinal (GI) variceal bleeding despite previous endoscopic sclerotherapy. All patients had melena, splenomegaly, hypersplenism, or some combination thereof. Left portal vein (LPV) patency was verified in 22 patients using intraoperative direct portography through the umbilical vein. Partial splenectomy was performed to enable the harvest of the splenic vein trunk, which was anastomosed between the superior mesenteric vein (SMV) and the left portal vein (LPV). All patients were followed for 12–48 months (mean=25.6 months) and no patients were lost to follow-up.

Results

Preoperative Doppler ultrasound (US) imaging indicated that 18/25 patients had adequate intrahepatic portal veins for shunting, with no blood flow in the LPVs of 7 patients. LPV patency in 22/25 patients was verified using intraoperative direct portography, with successful MRB. Shunting was converted into a portosystemic shunt in the remaining 3/25 patients with thrombosed LPVs. A Doppler US evaluation of the vein conduit revealed excellent postoperative flow. The patients’ mean hemoglobin, platelet, and white blood cell counts increased significantly, and in all cases the endoscopic status obviously improved after shunting. Occlusion or narrowing occurred in 2/22 patients after discharge. At 12 months (for 1 patient) and 24 months (for 1 patient), the shunt was converted into a portosystemic shunt. The cumulative graft patency rate was 91% (20/22).

Conclusions

Partial splenectomy and splenic vein autografting in MRB surgery can successfully resolve prehepatic portal hypertension and hypersplenism in children.

Management of portal hypertension in children

Portal hypertension can be caused by a wide variety of conditions. It frequently presents with bleeding from esophageal varices. The approach to acute variceal hemorrhage in children is a stepwise progression from least invasive to most invasive. Management of acute variceal bleeding is straightforward. But data on primary prophylaxis and long term management prevention of recurrent variceal bleeding in children is scarce, therefore prospective multicenter trials are needed to establish best practices.

Experience with duplex sonographic evaluation of meso-rex bypass in extrahepatic portal vein obstruction

Meso-Rex bypass is a surgical procedure for managing extrahepatic portal vein obstruction in children. Although duplex sonography has been used for assessing the patency of the bypass graft and the changes in the intrahepatic portal venous system after the surgery, there was little sonographic description of functioning and dysfunctioning bypass grafts found in the literature. In this case series, we retrospectively evaluated duplex sonography of functioning and dysfunctioning bypass grafts in 5 pediatric patients who received meso-Rex bypass grafts. Sonography was performed preoperatively and postoperatively within 48 hours, 1 to 2 weeks later, and at follow-up 1 month and up to 3 years later. Changes in the direction and velocity of the flow in the intrahepatic portal veins and bypass grafts and diameters of the grafts and the left portal veins were analyzed. Preoperative sonography revealed varied extension of extrahepatic portal vein occlusion with cavernous transformation and diminished intrahepatic portal venous flow, whereas postoperative studies showed a rapid increase of the intrahepatic portal flow via the meso-Rex bypass graft in all cases. A patent graft with reversed flow in the left portal vein was a predominant feature of a functioning graft. In contrast, absent flow in the graft with diminished flow or an altered flow direction in the left portal vein indicated graft failure. It is believed that duplex sonography provides a valuable tool for monitoring the hemodynamic changes in the portal venous system and detecting graft malfunction.

A large portal vein: a rare finding of recent portal vein thrombosis

Acute portal vein thrombosis (PVT) is rarely encountered by clinicians. The most common manifestation of acute PVT is sudden onset of abdominal pain. A computed tomography scan without contrast often shows a high-density material in the portal vein. After injection of contrast agents, absence of luminal enhancement and enlargement of the obstructed portal vein are shown. In this case report, we demonstrated a rare computed tomography finding in which the diameter of the main portal vein was enormously distended to 3-fold that of the aorta in a patient with recent PVT. Despite thrombolysis and anticoagulation were immediately given, portal venous recanalization was not achieved in the patient. After 5 years, variceal bleeding and ascites occurred and liver function had persistently deteriorated. Finally, he died of progressive liver failure. Considering this case, we suggest that an early decision for invasive interventional treatment might be necessary to both increase the rate of portal venous recanalization and improve prognosis, as anticoagulation and thrombolysis therapy failed to recanalize recent PVT.

Symptomatic portal biliopathy: a single centre experience from the UK

BACKGROUND AND METHODS

Biliary obstruction as a consequence of portal biliopathy, because of extrahepatic portal vein occlusion is an uncommon cause of biliary disease in the western world. We reviewed all patients presenting to the Regional Liver Transplant Unit in Birmingham, UK with symptomatic portal biliopathy between 1992 and 2005 and report the presentation, investigation, management and outcome of these complex patients.

RESULTS

Thirteen patients with symptomatic portal biliopathy were followed up for a median of 2 years (range 1-18 years). Jaundice was the presenting feature in all cases and was associated with bile duct stones or debris in 77% (10 of 13) of cases. Successful treatment of biliary problems was achieved by biliary decompression in six cases (metallic stent=three, plastic stent=one, combined procedure=one and sphincterectomy=one) and portal decompression in three cases (transjugular intrahepatic portosystemic shunt=two, meso-caval shunt=one). Successful biliary drainage could not be achieved endoscopically or by portal decompression in one case that was accepted for combined liver and small bowel transplantation. Three patients had spontaneous resolution without recurrence over the follow-up period. Ten patients (77%) experienced gastrointestinal bleeding. Two deaths over the follow-up period occurred; both were associated with portal hypertensive bleeding.

CONCLUSION

Endoscopic management (sphincterectomy and stone extraction or stent insertion) is effective initial therapy for patients with symptomatic portal biliopathy. In the case of persistent biliary obstruction porto-systemic shunting (transjugular intrahepatic portosystemic shunt or surgical) should be considered, however, the extent of vascular thrombosis precludes this in most cases.

Magnetic resonance cholangiography features of biliary abnormalities due to cavernous transformation of the portal vein

BACKGROUND

The aim of this retrospective and monocentric study was to describe the magnetic resonance cholangiography (MRC) features of biliary abnormalities related to extrahepatic obstruction of the portal vein (EHOPV).

METHODS

From September 2001 to May 2003, MRC was performed in 10 consecutive patients who had a portal thrombosis.

RESULTS

Biliary ductal pathology was demonstrated via MRC in nine patients. It consisted of stenoses, ductal narrowing or irregularities involving the common bile duct for three patients with extrahepatic portal vein thrombosis discovered a mean of 1.5 years ago, or involving both right and left intrahepatic bile ducts and common bile duct for six patients with extrahepatic portal vein thrombosis discovered a mean of 16.2 years ago. Dilation of intrahepatic bile ducts was seen for seven patients, four of them having cholestasis. For three patients with symptomatic cholestasis, direct cholangiography (DC) was performed and showed the same findings as MRC which nevertheless overestimated the degree of bile duct stenosis.

CONCLUSIONS

MRC seems to constitute an accurate tool to investigate noninvasively patients with portal biliopathy.

A patient with adult extrahepatic portal obstruction, of which distinction from intrahepatic cholangiocarcinoma was difficult

A 51-year-old Japanese male with chief complaints of slightly high fever and epigastralgia was hospitalized at our facility. The inflammatory response was enhanced, and liver dysfunction was observed. Abdominal ultrasonography demonstrated a hyperechoic lesion occupying the left portal vein, and abdominal plain CT indicated a low density of the lesion with a clear boundary, measuring about 3 cm x 2 cm, between the porta hepatis and segment IV of the liver. Contrast CT showed no enhancement in the arterial and portal phases, but a reduction in the density inside the tumor in the equilibration phase was noted. MRI showed hypointensity by T1-weighted imaging and hyperintensity by T2-weighted imaging. Angiography demonstrated an obstruction of the left portal vein and superior mesenteric vein, and endoscopic retrograde cholangiography revealed a constriction in the left intrahepatic bile duct. Since the possibility of intrahepatic cholangiocarcinoma could not be excluded, extended left hepatectomy combined with caudate lobectomy was performed. The tumor, measuring 31 mm x 21 mm x 20 mm, was pathohistologically diagnosed as an extrahepatic portal obstruction. Extrahepatic portal obstruction is an important disease that is sometimes difficult to rule out oncologic origin.

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Disappearance of "pseudocholangiocarcinoma sign" in a patient with portal hypertension due to complete thrombosis of left portal vein and main portal vein web after web dilatation and transjugular intrahepatic portosystemic shunt

The main portal vein web is probably a consequence of portal vein thrombosis, which is a very rare cause of portal hypertension. Principal manifestations are related to the degree of portal hypertension. In the literature, no data has been found for the treatment modality of portal vein web. We report, herein, the clinical and laboratory findings of a 38-year-old woman with angiographically proven incomplete main portal vein web and complete thrombotic occlusion of the left portal vein causing pseudocholangiocarcinoma sign (PCCS) on the common bile duct. She was treated by transjugular intrahepatic portosystemic shunt (TIPS) and membrane dilatation, which resulted in complete disappearance of collaterals and PCCS. It appears that TIPS and balloon dilatation of the portal vein web via transjugular approach was effective in decreasing portal pressure and its consequences.

Hepatic cirrhosis and portal hypertension in neuroblastoma

Hepatic portal hypertension is an unusual complication of cancer therapy. The authors report 2 children under the age of 18 months with disseminated neuroblastoma who developed cavernous transformation of the portal vein during chemotherapy. While the older child remains well, the second patient succumbed from overwhelming variceal hemorrhage as a result of this condition. Full recovery of hepatic function is not invariable following the regression of extensive liver infiltration by neuroblastoma and consideration should be given to follow-up Doppler ultrasound imaging of the hepatic portal system in affected infants.

CO(2) wedged hepatic venography in the evaluation of portal hypertension

BACKGROUND/AIMS/METHODS

During hepatic vein catheterisation, in addition to measurement of hepatic venous pressure gradient (HVPG), iodine wedged retrograde portography can be easily obtained. However, it rarely allows correct visualisation of the portal vein. Recently, CO(2) has been suggested to allow better angiographic demonstration of the portal vein than iodine. In this study we investigated the efficacy of CO(2) compared with iodinated contrast medium for portal vein imaging and its role in the evaluation of portal hypertension in a series of 100 patients undergoing hepatic vein catheterisation, 71 of whom had liver cirrhosis.

RESULTS

In the overall series, CO(2) venography was markedly superior to iodine, allowing correct visualisation of the different segments of the portal venous system. In addition, CO(2), but not iodine, visualised portal-systemic collaterals in 34 patients. In cirrhosis, non-visualisation of the portal vein on CO(2) venography occurred in 11 cases; four had portal vein thrombosis and five had communications between different hepatic veins. Among non-cirrhotics, lack of portal vein visualisation had a 90% sensitivity, 88% specificity, 94% negative predictive value, and 83% positive predictive value in the diagnosis of pre-sinusoidal portal hypertension.

CONCLUSIONS

Visualisation of the venous portal system by CO(2) venography is markedly superior to iodine. The use of CO(2) wedged portography is a useful and safe complementary procedure during hepatic vein catheterisation which may help to detect portal thrombosis. Also, lack of demonstration of the portal vein in non-cirrhotic patients strongly suggests the presence of pre-sinusoidal portal hypertension.

Thrombosis of the portal vein in a miniature schnauzer

A miniature schnauzer with a history of apathy, anorexia and jaundice was presented to the Utrecht University Clinic for Companion Animals. Abnormal laboratory findings included highly increased levels of total bile acids and alkaline phosphatase, and hyponatraemia. Abdominal ultrasonography revealed that the right side of the liver was enlarged and the left side was small, together with a thrombus in the portal vein. Biopsies from the right side of the liver demonstrated subacute to chronic active hepatitis, for which the dog was treated with prednisolone (1 mg/kg/day for four weeks). No improvement was observed and the owner requested euthanasia. At necropsy the left lobes of the liver were found to be small and firm, while the right lobes were large and soft. There were two thrombi in the portal vein. Microscopic examination revealed chronic active hepatitis and cirrhosis.

Acute presentation of ascites in association with colon cancer

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Direct bypassing of extrahepatic portal venous obstruction in children: a new technique for combined hepatic portal revascularization and treatment of extrahepatic portal hypertension

BACKGROUND

Decompression of extrahepatic portal hypertension by directly bypassing the thrombosed portal vein has never been reported in cases of children with idiopathic (or neonatal) portal vein obstruction and cavernoma.

METHODS

Seven children (15 years or younger) with portal vein obstruction requiring surgical decompression (urgently in two cases), and in whom preoperative Doppler had shown that the intrahepatic portal branches were hypoplastic but free of thrombus, were included in a pilot study. The cavernoma was bypassed by interposing a venous jugular autograft between the superior mesenteric vein and the distal portion of the left portal vein. Patients received follow-up using routine clinical parameters, upper gastrointestinal endoscopy, and Doppler ultrasound.

RESULTS

The mesenterico-portal bypass restored a direct (physiological) hepatopetal portal flow. The operation resulted in effective portal decompression as demonstrated by decrease of the pressure gradient, rapid regression of clinical signs of portal hypertension, and definitive control of bleeding.

CONCLUSIONS

This study shows that direct bypassing of portal cavernoma is possible and results in effective portal decompression. Restoration of the hepatic portal flow is a major advantage compared with conventional surgical shunting procedures. This new technique is potentially applicable to two thirds of children with portal vein thrombosis and should be considered when shunting procedures are indicated.

Extrahepatic portal venous obstruction in childhood: etiology, clinical and laboratory findings and prognosis of 34 patients

Extrahepatic obstruction of the portal vein is a well known cause of portal hypertension in childhood, that causes severe morbidity. We evaluated 34 children (24 boys, 10 girls, age 4.5 months to 12 years, mean 5.5 +/- 3.8 years) with this diagnosis, to define the clinical picture, laboratory changes, diagnostic tools and therapeutic modalities. Gastrointestinal bleeding was the commonest mode of presentation (64.7%), with the second being splenomegaly. The cause of the obstruction could be determined in 38.2% (13/34) of the subjects. At the beginning of the study the main diagnostic procedure was splenoportography although in more recent years pulsed duplex Doppler ultrasonography has been used. The follow up period was median of 5 years (range 1-11 years). The mean number of bleeding episodes was 4.7 +/- 5.9 (range 1-26), while nine patients never bled. There was no mortality. Ten patients underwent surgery, while sclerotherapy was performed on 10. Twenty-one patients received beta-blocker drugs. No difference was found among these therapeutic modalities. It is well established that the major risk for children with extrahepatic portal vein obstruction is gastrointestinal bleeding which is tolerated quite well. Surgery should be indicated only in children where bleeding cannot be controlled by medical means including sclerotherapy.

Cavernous transformation of the portal vein in a child with non-Hodgkin's lymphoma

We present an 11 year old boy who developed collateral vessels in the portal hepatis with non-visualization of the portal vein 9 months after treatment for large cell lymphoma. This "cavernous transformation of the portal vein" may lead to varices with subsequent gastrointestinal hemorrhage.

Biliary obstruction caused by portal cavernoma: a study of 8 cases

BACKGROUND/AIMS

Biliary obstruction secondary to portal cavernoma is a rare and little-known entity. From 1985 to 1994, we observed eight cases of portal cavernoma compressing the biliary tract. We report here the features of biliary involvement in these cases of portal cavernoma including the circumstances of diagnosis, biliary tract morphology, liver pathology and the efficiency of various treatments.

METHODS AND RESULTS

The causes of portal vein obstruction were portal vein thrombosis in one case, peritonitis in another, omphalitis in two cases, portal vein catheterization in one case and unknown in two cases. The portal cavernoma was revealed through esophageal varices ruptures in four patients. The mean time from portal cavernoma diagnosis to biliary involvement was 8 years (range 0-21). Six patients had acute cholangitis, one of whom revealed portal vein obstruction. All the patients had abnormal liver function tests. Imaging techniques (transparietal abdominal ultrasonography and abdominal computed tomography scan [n = 8], endosonography [n = 5] and endoscopic retrograde cholangiography [n = 7]) showed in all cases an extraluminal obstacle, laminating the common bile duct. Pathologic examination of the liver showed secondary biliary cirrhosis in one patient, periportal and perisinusoidal fibrosis in another and no abnormalities in three other cases. Three patients were treated by endoscopic sphincterotomy but cholangitis persisted in two cases, leading to death in one. One patient who underwent a splenorenal shunt was symptom-free 60 months after surgery. Balloon endoscopic dilatation of the common bile duct, performed in one case, led to normalization of liver biological tests. The patients with abnormal liver pathology were treated by propranolol and ursodesoxycholic acid. No complication had occurred after 6 and 24 months of follow-up.

CONCLUSIONS

In conclusion, eliminating biliary obstruction seems to be essential in providing the best change of survival for patients when biliary obstruction becomes symptomatic. In cases of abnormal liver pathology, associating propranolol with ursodesoxycholic acid would seem to be useful.

Hepatic artery interruption followed by portal vein thrombosis in an adult liver transplant

Vascular complications following liver transplantation result in significant morbidity and mortality. We report a 28-year-old man who, because of a mycotic false aneurysm, underwent ligation of the hepatic artery 4.5 weeks post-transplantation and who, 4.5 months later, suffered a portal-mesenteric vein thrombosis. Adverse hepatic sequelae did not follow these events, demonstrating the capacity of the collateral circulation to perfuse the transplanted liver.

Idiopathic acute portal vein thrombosis: a case report

There are few reported cases of acute portal vein thrombosis presenting as an acute abdomen in adolescent age group. Most published series concern chronic extrahepatic portal vein thrombosis. Acute portal vein thrombosis is rare, but can develop into serious complications. Hence, prompt diagnosis and heparinization can prevent the development of lethal complications such as venous gangrene of the bowel and portal hypertension.

Biliary abnormalities associated with extrahepatic portal venous obstruction

We prospectively studied 21 consecutive patients with extrahepatic portal venous obstruction for evidence of biliary tract disease. Two patients were first seen with extrahepatic cholestasis; another had recurrent cholangitis. All three patients with clinically manifest biliary disease were adults. Another five patients had icterus on clinical examination. Liver function tests revealed elevated bilirubin levels in 14 patients (66.6%), elevated alkaline phosphatase levels in 17 (80.9%) and elevated serum ALT levels in 8 (38.0%). Endoscopic retrograde cholangiography revealed abnormal findings in 17 patients (80.9%). The changes involved the common bile duct (66.6%) more often than they did the hepatic bile ducts (38.1%). Cholangiographic abnormalities included strictures (52.4%), caliber irregularity (23.8%), segmental upstream dilatation (42.8%), ectasia (9.5%), collateral veins causing extraluminal bile duct impressions (14.3%), displacement of ducts (9.5%), angulation of ducts (4.7%) and pruning of intrahepatic ducts (9.5%). The pathogenesis of such cholangiographic abnormalities is unknown. However, possible factors in such changes include collateral veins bridging the blocked portal vein, causing bile duct impressions; fibrous scarring of porta hepatis, causing angulation of bile duct; and ischemic injury to bile duct, leading to stricture formation and caliber irregularity. Biliary disease is important in the clinical outcome of patients with extrahepatic portal venous obstruction because variceal sclerotherapy has prolonged the life expectancies of such patients.

Obstructive jaundice associated with extrahepatic portal vein obstruction: report of two cases

We herein report two cases of obstructive jaundice with markedly dilated collateral veins either in or around the bile duct in the setting of extrahepatic portal vein obstruction (EHPO). In the first case, a proximal splenorenal shunt provided relief of biliary stenosis as well as eradication of esophageal varices due to a decompression of portal hypertension. This evidence proved that the markedly extended collateral veins in the hepatoduodenal ligament caused biliary stenosis by compressing the bile duct. In the second case, obstructive jaundice was probably caused by cholangitis and was relieved with biliary drainage. Portal decompressive surgery was not indicated because of the slight degree of esophageal varices. The relationship between cholangitis and EHPO in these patients calls for further investigation. In cases with EHPO manifesting obstructive jaundice associated with risky esophageal varices, portal decompressive surgery is recommended as the procedure of choice.

Non-invasive diagnosis of portal vein occlusion by radionuclide angiography

The accuracy of non-invasive radionuclide angiography in detecting portal vein occlusion was assessed in 61 patients--10 with portal vein occlusion confirmed by conventional portography, 25 with chronic liver disease and a patent portal vein (mild = 12, severe = 13), and 26 with normal liver function, who served as controls. The median percentage portal venous flow for the portal vein occlusion group was 8% (range 1-30) (consistent with negligible flow) compared with 78% (52-87) for control subjects (p < 0.005) and 68% (61-80) and 49% (23-59) respectively for patients with mild and severe liver disease (p < 0.001 and p < 0.005). At a portal venous inflow of < 20%, the procedure had a specificity of 100% and sensitivity of 90% in diagnosing portal vein occlusion. Non-invasive radionuclide angiography provides a safe and accurate screening method for evaluating portal vein patency or occlusion in the investigation of portal hypertension or before liver transplantation.

Long-term follow-up study of adult patients with non-cirrhotic obstruction of the portal system: comparison with cirrhotic patients

Thirty-two patients with non-cirrhotic portal system obstruction and oesophageal varices of non-malignant etiology were recruited over 13 years. Diagnosis was based on the presence of oesophageal varices at endoscopy, minor alterations in liver function tests and liver histology, a low hepatic venous pressure gradient, and pertinent angiographic patterns. Twenty-three had portal vein thrombosis, nine had splenic vein thrombosis. Twenty-one had idiopathic portal vein obstruction, 11 had secondary obstruction. The outcome was compared with a group of 32 patients with cirrhosis and portal hypertension, matched for age, Child-Pugh class, previous history of gastrointestinal bleeding, and size of oesophageal varices. Patients with non-cirrhotic obstruction of the portal system were followed for up to 171 months (mean 94 months). During follow-up ten patients had gastrointestinal bleeding, and eight died (five of gastrointestinal bleeding). After 6 years of follow-up, the cumulative risk of gastrointestinal bleeding was 24%, the cumulative risk of death was 17%, and the cumulative risk of death from gastrointestinal bleeding was 14%. Cumulative probability of death by any cause and the probability of gastrointestinal bleeding were significantly lower in patients with non-cirrhotic obstruction of the portal system than in patients with cirrhosis comparable for liver function and portal hypertension (p = 0.04 for both). The cumulative probability of death by gastrointestinal bleeding was not significantly different. In conclusion, the prognosis for non-cirrhotic obstruction of the portal system is significantly better than for patients with cirrhosis with comparable levels of liver function impairment and severity of portal hypertension.

Adult "idiopathic" extrahepatic venous thrombosis. Importance of putative "latent" myeloproliferative disorders and comparison with cases with known etiology

The etiology of extrahepatic venous obstruction (EHVO) is unknown in 50% of cases. Recently the presence of a "latent" myeloproliferative disorder has been reported in adults with "idiopathic" EHVO. We evaluated the course of these patients to establish if any putative latent myeloproliferative disorder influenced the clinical course compared to those with a known cause. Among 132 EHVO patients, 78 (59%) had a known etiology, 7 (5%) with an overt myeloproliferative disorder. The "idiopathic" group had 54 patients; 24 (13 men, 11 women) were diagnosed after 15 years of age, (median 38 years, range 17-70) with a median follow up of 96 months (19-372). Only 2 (8%) developed an overt myeloproliferative disorder. These 24 had a similar pattern of bleeding and onset of ascites as those with known cause. In EHVO failure to diagnose a latent myeloproliferative disorder does not influence the course of variceal bleeding, and thus has little prognostic significance.

Portal-vein obstruction in children leads to growth retardation

The portal vein is the main source of blood and hepatotrophic factors to the liver. Partial portal-vein ligation in rats results in reduced growth compared with that in control rats. To investigate whether extrahepatic portal vein obstruction occurring in early childhood influences growth in humans, anthropometric and nutritional assessments were prospectively carried out in 61 patients with extrahepatic portal vein obstruction. Comparisons were made with 183 matched healthy controls using National Center of Health Statistics reference. Fifty-one percent of children with extrahepatic portal vein obstruction had stunted growth (height for age less than 90% of normal), compared with 16% of controls (p less than 0.01). Growth retardation was severe in patients with longer (greater than 5 yr) than with shorter (less than 2.5 yr) duration of clinical portal hypertension (height for age, 88.0 +/- 3.2 vs. 95.1 +/- 3.0; p less than 0.01). Little difference was seen in the energy intake (1,302 +/- 463 kcal/day vs. 1,335 +/- 449 kcal/day; p = not significant) and weight for height index (83.6 +/- 9.3 vs. 88.0 +/- 7.9; p = not significant) between extrahepatic portal vein obstruction patients and controls. This suggested that despite comparable nutrition, marked growth retardation occurred in extrahepatic portal vein obstruction patients. Incremental growth velocity was studied in 31 patients; in 24 (73%) the baseline Z score (-2.1 +/- 0.2) had decreased further (-2.4 +/- 0.2) at the end of follow-up (15.5 +/- 1.6 mo). Although the incremental height velocity was only 56% of the expected height, incremental weight gain was 98% of the expected weight for the attained height.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanisms and consequences of portal hypertension

Portal hypertension is characterised by alterations in the splanchnic and systemic circulation resulting in the development of portosystemic collateral channels, the most important of which are found in the lower oesophagus and stomach. The major clinical complication of gastro-oesophageal varices is bleeding and over the last decade there has been considerable interest in the pharmacological management of this complication. The factors currently implicated in the development of gastro-oesophageal varices in patients with cirrhosis include a) increased portal vascular resistance, b) splanchnic and systemic vasodilatation and c) changes in the lower oesophageal venous anatomy [palisade and perforating venous zones]. In a patient with gastrointestinal bleeding, endoscopic examination of the upper gastrointestinal tract will confirm the diagnosis of portal hypertension by confirming the presence of gastro-oesophageal varices. Cirrhosis is the most common aetiological factor for gastro-oesophageal varices, but imaging techniques, including Doppler ultrasound, computerised tomography and venous phase angiography, may be required to exclude extrahepatic portal venous obstruction from the differential diagnosis. Although the pathogenesis of variceal rupture remains unclear, several risk factors for variceal haemorrhage have been identified, including a) increased size, b) high intravariceal-portal pressure, c) increased varix wall tension characterised by the presence of red spots observed at endoscopy (particularly in large varices since wall tension is related to variceal size), and d) poor liver function. Although oesophagitis may be observed at endoscopy, an erosive mechanism is no longer considered to be of pathogenic significance. A high portal pressure in the immediate postbleeding period is now recognised as predictive of rebleeding. Periodic elevations in intravariceal pressure, associated with the release of enhanced endogenous vasoactive compounds, or beta-adrenergic-mediated stress-related increases in portal pressure, may contribute to the rupture mechanism. Consequently, portal hypertension is now being more widely considered as a multiorgan disorder associated with changes in blood flow within both systemic and splanchnic vascular beds. This article reviews the factors currently implicated in the development of portal hypertension and the approach to diagnosis. The pathogenesis of variceal bleeding will also be considered.

A digital splenoportography: more sensitive method of detecting spontaneous splenorenal shunt

Splenoportography was performed upon 195 pediatric patients, including 137 by conventional technique and 58 by digital subtraction technique. The results obtained were compared, and it was found that the percentage of diagnosis of spontaneous splenorenal shunt was higher with digital than with conventional technique. In conclusion digital technique is a more sensitive and safer method than the conventional method.

Management of variceal bleeding in patients with extrahepatic portal vein thrombosis

Patients with extrahepatic portal vein thrombosis may present from infancy through adulthood with variceal bleeding. Physiologically, such patients differ from patients with cirrhosis and variceal bleeding in that they have a normal liver and maintain good portal perfusion through hepatopedal collaterals. Complete evaluation of these patients requires identification of the bleeding site by endoscopy, definition of the anatomy by angiography, and confirmation of a normal liver by biopsy examination. Causative factors, including hypercoagulable states, should be evaluated. Therapeutic options range from noninterventive, through ablative procedures, to shunt operations. The goal should be definitive control of bleeding and return to a normal lifestyle. Distal splenorenal shunt offers the best option if technically feasible, but if no shuntable veins are patent, ablative procedures and sclerotherapy may be required. A noninterventive, noninvestigational approach is inappropriate in patients who can be offered definitive therapy. Splenectomy for hypersplenism should not be done in these patients.

Extrahepatic portal venous obstruction of different pathogenesis in pancreatic diseases: reports of 4 autopsy cases with chronic pancreatitis and pancreatic carcinoma

Four autopsy cases of extrahepatic portal venous obstruction associated with pancreatic diseases, 1 case of pancreatitis and 3 cases of pancreatic carcinoma, are presented. The pathogenesis of portal obstruction was different in each case; old thrombosis with recanalization due to chronic pancreatitis with pseudocysts formation in 1 case, fresh thrombosis due to intraportal venous catheterization for pancreatic carcinoma in 1 case, fresh thrombosis probably due to pancreatitis accompanying pancreatic carcinoma in 1 case, and direct invasion of pancreatic carcinoma into the portal vein in the remaining 1 case. Morphologic evidence for portal hypertension was present in each case. In the pancreatitis case and one pancreatic carcinoma case with portal tumor invasion, both of which had chronic portal obstruction, there were many thin-walled vascular channels (cavernous transformation) around the occluded portal vein. Their endothelia were positive for factor VIII-related antigen and Ulex europaeus lectin I, implying that these vessels were hepatopetal blood vascular collaterals. It was shown that pancreatic diseases resulted in portal venous obstruction by several different mechanisms and chronic portal obstruction in pancreatic diseases led to the formation of hepatoperal blood vascular collaterals.

Development of cavernous vasculatures in livers with hepatocellular carcinoma. An autopsy study

The incidence and morphology of cavernous vasculatures in livers with hepatocellular carcinoma were examined. These vasculatures were grossly or microscopically found in 64% of 102 autopsied livers with hepatocellular carcinoma, though the incidence of grossly visible vasculatures was only 7%. These vasculatures were preferentially found within the portal tracts in the vicinity of portal veins obstructed by tumor emboli, especially in the cases with marked tumor emboli of the portal venous system. A majority of these vasculatures showed histochemical and immunohistochemical characteristics of blood vessels. Our findings suggest that these vasculatures frequently develop as collaterals of portal veins obstructed by the tumor emboli in hepatocellular carcinoma.

Vascular plexus around intrahepatic bile ducts in normal livers and portal hypertension

Vessels around the intrahepatic large bile ducts (peribiliary vascular plexus) were examined by histologic, immunohistochemical and scanning electron microscopic observations. The vessels within duct walls were mainly capillaries, while those around the duct walls were composed of capillaries and venules. A majority of vessels was positive for factor VIII-related antigen and Ulex europaeus lectin I. Scanning electron microscopy of hepatic arterial and biliary casts revealed that bile ducts were surrounded by the vascular plexus derived from hepatic arterial branches, and serial section observations in addition disclosed the vessels connecting the peribiliary plexus with portal venous branches ('internal roots'). The peribiliary vascular plexus was increased considerably in livers with portal hypertension, especially idiopathic portal hypertension, extrahepatic portal venous obstruction and hepatocellular carcinoma with portal venous tumor thrombi. Internal roots were also frequently found in the livers with portal hypertension. These results suggest that altered intrahepatic hemodynamics in portal hypertensive conditions involves the peribiliary vascular plexus, resulting in an increase of the number and frequent occurrence of 'internal roots', these vessels probably operating as intrahepatic collaterals.

Model for the study of portal-systemic collateral vascular resistance in the conscious rat

In order to obtain a model for the study of portal-systemic collateral vascular resistance, total portal vein occlusion was performed in rats 48 hr or 3 wk after partial obstruction. Four groups of conscious restrained rats were studied: a) sham-operated, b) partial portal vein ligated, c) 48 hr-total portal vein occluded, and d) 3 wk-total portal vein occluded. In comparison with the sham group, the three portal vein ligated groups had significantly higher cardiac output, portal tributary blood flow, portal pressure (7.7 +/- 0.4 versus 13.5 +/- 0.5, 13.6 +/- 0.8, and 17.7 +/- 1.1 mmHg, mean +/- SE, respectively) and hepatic arterial blood flow (5.8 +/- 0.6 versus 9.5 +/- 0.7, 8.3 +/- 0.5, and 13.9 +/- 1.9 ml/min, respectively). Cardiac output and portal tributary blood flow did not differ between the portal vein ligated groups, but portal pressure and hepatic arterial blood flow were significantly higher in the 3 wk-total portal vein occlusion group. The 3 wk-total portal vein occlusion group showed 99.1 +/- 0.3% shunting, different from the partial (29.7 +/- 16.9%, p less than 0.01) and 48 hr-total portal vein occlusion (46.5 +/- 14.7%, p less than 0.05) groups. Portography confirmed absence of portal-portal collaterals in the 3 wk-total portal vein occlusion group. It is suggested that rats with 3 wk-total portal vein occlusion are useful for the study of acute modifications of portal-systemic collateral circulation, as shunting is total and consistent in this model.