History
In the acute phase, the presentation of portal vein obstruction is relatively uncommon and easily missed because the patient may be asymptomatic. Symptoms most often begin in the chronic or subacute stage. Schistosomiasis can cause presinusoidal portal obstruction by blocking the intrahepatic portal venules with parasite eggs. It does not cause extrahepatic portal vein obstruction, though the clinical manifestations are often similar.
Acute
Patients can present emergently with sudden onset of right upper quadrant pain, nausea, and/or fever. Alternatively, the symptoms of the primary infectious and inflammatory condition that led to the portal vein obstruction predominate (eg, right lower quadrant pain in appendicitis).
Progressive ascites, intestinal ischemia resulting from the propagation of the thrombus, or intestinal suffusion secondary to acute portal hypertension can also be the presenting manifestations. Occasionally, variceal bleeding can occur acutely with the development of portal vein thrombosis, particularly in the setting of preexisting varices with cirrhosis.
Spontaneous resolution of acute/recent thrombosis undoubtedly occurs and symptoms abate. In other patients, the acute symptoms often subside as collaterals develop, and the diagnosis may be missed. These patients then present at a later stage with manifestations of portal hypertension.
Chronic
These groups of patients most often present with complications related to portal hypertension. In 90% of cases, variceal bleeding is the presenting complaint. On average, this occurs 4 years after the thrombotic event and has been described as long as 12 years later. Ascites is less frequent, and hepatic encephalopathy is rare in the absence of preexisting cirrhosis. [8]
The specific etiology of the portal vein obstruction not only influences the initial clinical presentation but also the time course and prognosis.
In the presence of cirrhosis with underlying hepatic insufficiency, sudden worsening of hepatic function, development of hepatic encephalopathy, and the development of ascites are all more frequent, leading to worse outcomes.
With intra-abdominal malignancies, bleeding is less commonly the first manifestation because many of these patients do not survive long enough to develop the sequelae of portal hypertension. These patients most often present with sudden ascites, anorexia, right upper quadrant or epigastric pain, and weight loss. Portal vein obstruction may also be discovered incidentally on imaging studies obtained for pain or ascites.
Rarely, patients with portal vein obstruction present with a fever of unknown origin.
Physical Examination
Splenomegaly is found in 75-100% of patients, most presenting in the chronic stage. Mild hepatomegaly is often present, as is right upper quadrant epigastric tenderness, especially in the acute setting.
Ascites is found infrequently. Stigmata of chronic liver disease, such as spider angiomata or palmar erythema, are usually found in the presence of an underlying liver disease.
The presence of caput medusae indicates posthepatic or intrahepatic portal hypertension because it forms by recanalization of the umbilical vein, which connects with the left hepatic branch of the portal vein. [9] It should not be observed in isolated extrahepatic portal vein obstruction because the obstruction is below the origin of the umbilical vein.
In children, growth retardation may be present. [10, 11]
Abnormalities of the extrahepatic biliary tree may occur in 80% of cases due to compression by choledochal or periportal varices or from ischemic stricturing. These findings manifest by jaundice, cholangitis, hemobilia, cholecystitis, or a hilar mass that can be mistaken for a cholangiocarcinoma.
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The etiology of portal vein obstruction.
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Coagulation disorders in portal vein thrombosis.
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Portal vein thrombosis with cavernous transformation. The long arrow indicates the splenic vein at the junction with the superior mesenteric vein just below the site of the thrombosis. The short arrow points to a serpiginous mass consistent with periportal collaterals, the so-called cavernous transformation of the portal vein.
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Hepatocellular carcinoma with portal vein thrombosis. The short arrow indicates the tumor thrombus with an abrupt cut off of the portal vein. The long arrow points to a compensatory, prominent left hepatic arterial branch.
