Noncirrhotic Portal Hypertension

Essentials of Diagnosis

• Upper gastrointestinal bleeding from esophageal or gastric varices in patients without liver disease

• Splenomegaly

• Portal vein thrombosis complicating cirrhosis

General Considerations

• Causes include

  • Extrahepatic portal vein obstruction (portal vein thrombosis often with cavernous transformation [portal cavernoma])

  • Splenic vein obstruction (presenting as gastric varices without esophageal varices)

  • Schistosomiasis

  • Nodular regenerative hyperplasia

  • Arterial-portal vein fistula

• Risk factors

  • Oral contraceptive use

  • Pregnancy

  • Chronic inflammatory diseases (including pancreatitis)

  • Injury to the portal venous system (including surgery)

  • Hepatocellular carcinoma and other malignancies

  • Treatment of thrombocytopenia with eltrombopag

• Idiopathic noncirrhotic portal hypertension

  • Common in India

  • Rare in Western countries

  • Has been attributed to

    • Chronic infections

    • Exposure to medications or toxins

    • Prothrombotic disorders

    • Immunologic disorders

    • Genetic disorders that result in obliterative vascular lesions in the liver

• Portal vein thrombosis

  • May be classified as

    • Type 1: involving the main portal vein

    • Type 2: involving one (2a) or both (2b) branches of the portal vein

    • Type 3: involving the trunk and branches of the portal vein

    • Additional descriptors are occlusive or nonocclusive, acute or chronic, extent (eg, into the mesenteric vein), and nature of any underlying liver disease

  • May occur in 10–25% of patients with cirrhosis

    • Associated with the severity of the liver disease

    • May be associated with hepatocellular carcinoma but not with increased mortality

• "Obliterative portal venopathy" is used to describe primary occlusion of intrahepatic portal veins in the absence of cirrhosis, inflammation, or hepatic neoplasia

• Cases of noncirrhotic portal hypertension due to nodular regenerative hyperplasia have been reported in HIV-infected patients treated with didanosine or with a combination of didanosine and stavudine or didanosine and tenofovir

Symptoms and Signs

• Acute portal vein thrombosis usually causes abdominal pain

• Aside from splenomegaly, physical examination is unremarkable

• Hepatic decompensation can follow severe gastrointestinal bleeding or a concurrent hepatic disorder, and intestinal infarction may occur when portal vein thrombosis is associated with mesenteric venous thrombosis

• Ascites may occur in 25% of persons with noncirrhotic portal hypertension

• Low-grade hepatic encephalopathy is common in patients with noncirrhotic portal vein thrombosis

Laboratory Tests

• Complete blood count may reveal thrombocytopenia and other findings of hypersplenism

• Liver chemistries are usually normal

• An underlying hypercoagulable state is found in many patients with portal vein thrombosis

Imaging Studies

• Color Doppler ultrasonography and contrast-enhanced CT are usually the initial diagnostic tests for portal vein thrombosis

• Magnetic resonance angiography (MRA) of the portal system is generally confirmatory

• Endoscopic ultrasonography may be helpful in some cases

• In patients with jaundice, magnetic resonance cholangiography may demonstrate compression of the bile duct by a large portal cavernoma (portal biliopathy)

• In patients with pyelephlebitis, CT may demonstrate

  • An intra-abdominal source of infection

  • Thrombosis or gas in the portal venous system

  • Hepatic abscess

Diagnostic Studies

• Endoscopy shows esophageal or gastric varices

• A low liver stiffness measurement by elastography may help distinguish noncirrhotic portal hypertension from cirrhosis

• Needle biopsy of the liver

  • May be indicated to diagnose schistosomiasis, nodular regenerative hyperplasia, and noncirrhotic portal fibrosis

  • May demonstrate sinusoidal dilatation

Medications

• Anticoagulation (particularly with low-molecular-weight or unfractionated heparin) or thrombolytic therapy

  • May be indicated for isolated acute portal vein thrombosis (leads to at least partial recanalization in up to 75% of cases when started within 6 months of thrombosis) and possibly for acute splenic vein thrombosis

  • An oral anticoagulant may be continued long-term if a hypercoagulable disorder is identified or if an acute portal vein thrombosis extends into the mesenteric veins

• A possible role for enoxaparin to prevent portal vein thrombosis and hepatic decompensation in patients with cirrhosis has shown promise

Surgery

• Splenectomy is curative if splenic vein thrombosis is the cause of variceal bleeding

• Liver transplantation is required for progressive liver dysfunction (rare)

Therapeutic Procedures

• Band ligation followed by β-blockers to reduce portal pressure is initiated for variceal bleeding

• Portosystemic shunting (including TIPS) is reserved for when endoscopic therapy fails

When to Refer

• Refer all patients with noncirrhotic portal hypertension to a hepatologist