Noncirrhotic portal hypertension: recent concepts.

NCPH is a result of obliteration of portal veins. Many inflammatory conditions may initiate the process by causing endothelial injury. As obliteration progresses, there is local stasis and low-grade portal hypertension. In many cases, superimposed PVT occurs before portal hypertension becomes clinically evident. Hypercoagulability is an important cofactor. Diagnosis requires the exclusion of cirrhosis. Focal atrophy and nodular hyperplasia on biopsy may be a clue to the presence of small vessel obliteration. The distribution of vascular disease should be documented with Doppler ultrasound of both portal and hepatic veins. Investigation of cause should include tests for myeloproliferative and other hypercoagulable disorders, systemic diseases associated with vascular injury (eg, autoimmune diseases and toxin exposure) and local portal tract inflammatory diseases (primary biliary cirrhosis and sarcoidosis). Advances in this field will likely be made with improved diagnosis of acute and recanalized PVT using MRI, the new Acuson Sequoia ultrasound technology, and intravascular ultrasonography. Advances in the cause of PVT await studies using new and improved tests for the diagnosis of hypercoagulable states.