Review article: portal vein obstruction--epidemiology, pathogenesis, natural history, prognosis and treatment.

BACKGROUND: Portal vein obstruction may be due to portal vein thrombosis (PVT) or its sequale, the portal cavernoma. PVT is a common complication in liver cirrhosis, however, it may also occur as a primary vascular disorder, in absence of any liver disease.

AIM: To review the current knowledge on nomenclature, etiology, pathophysiology, clinical presentation, diagnostic workup and management of adult patients with obstruction in the portal vein, either as a primary vascular disease in adults, or as a complication of liver cirrhosis.

METHODS: A structured search in PubMed was performed using defined keywords (portal vein obstruction, extra-hepatic portal vein obstruction, PVT and portal cavernoma), including full text articles and abstracts in English language.

RESULTS: Several causes, operating both at local and systemic level, might play an important role in the pathogenesis of PVT. Frequently, more than one risk factor could be identified; however, occasionally no single factor is discernible. Diagnosis of portal vein obstruction depends on clinical presentation, imaging and laboratory investigations. Prompt treatment greatly affects the patient's outcome.

CONCLUSIONS: Portal vein obstruction occurring either due to thrombosis in the portal vein or due to the portal cavernoma, can contribute to significant morbidity and mortality in patients with or without cirrhosis. In recent years our understanding of etio-pathogenesis of portal vein obstruction has evolved tremendously, which has led to significant improvement in treatment outcomes. There are still areas where more studies are needed to better clarify the management issues of portal vein obstruction.