Prothrombotic disorders in abdominal vein thrombosis.

Abdominal vein thrombosis is a rare, but potentially life-threatening form of venous thrombosis. It mainly involves the hepatic veins (Budd Chiari syndrome, BCS), portal veins (PVT) and mesenteric veins. In recent years several large-scale studies have been performed to study the underlying aetiological factors in these thrombotic disorders. Both inherited and acquired thrombophilia factors are frequently observed in these patients. Factor V Leiden mutation is frequently found in patients with BCS and prothrombin gene variant is seen more frequently in PVT. Myeloproliferative neoplasms (MPNs), including polycythemia vera and essential thrombocythemia, are underlying disorders in 30-40% of patients with abdominal vein thrombosis. Other aetiological factors are paroxysmal nocturnal haemoglobinuria (PNH), autoimmune disorders and hormonal factors. Recently, several new risk factors have been reported and are discussed in this review. BCS and PVT are multi-factorial disorders. In nearly 50% of patients two, and in 16% even three prothrombotic risk factors were found at presentation. Because patients with abdominal vein thrombosis have a high risk of recurrence immediate anticoagulant treatment is necessary. The duration of treatment is still a matter of debate because these patients also have a high risk of bleeding, especially those with portal hypertension. For BCS patients life-long anticoagulant treatment is advised. In patients with PVT it is recommended to tailor treatment to the individual patient based on the presence of an underlying prothrombotic disorder and the risk of bleeding.

Long-term follow-up of patients with portal vein thrombosis and myeloproliferative neoplasms.

BACKGROUND: Myeloproliferative neoplasms (MPNs) are frequently identified as an underlying cause in patients with non-cirrhotic portal vein thrombosis (PVT). The aim of this study was to describe the long-term outcome of patients with PVT and MPN. METHODS: A cohort study was performed including all adult patients referred to our hospital between 1980 and 2008 with non-cirrhotic, non-malignant PVT and confirmed MPN. RESULTS: A total of 44 patients (70% female) were included, with a median age at PVT-diagnosis of 48 years (range 18-79). In 31 patients (70%) PVT was the first manifestation of an MPN. Additional risk factors for thrombosis were present in 20 patients (45%). Median follow-up was 5.8 years (range 0.4-21). Twenty-three patients (52%) were treated with oral anticoagulants after diagnosis of PVT, of whom 15 (34%) received long-term therapy. During follow-up, 17 patients (39%) experienced at least one episode of gastrointestinal bleeding. Additional thrombotic events occurred in 12 patients (27%). Twelve patients (27%) had progression of the underlying MPN. Seventeen patients (39%) died at a median age of 64 years (range 30-88). Death was directly related to end-stage MPN in eight patients (47%) and to a new thrombotic event in three patients (18%). No patients died from gastrointestinal bleeding. CONCLUSIONS: PVT is often the presenting symptom of an underlying MPN, highlighting the need for thorough screening for this disease. Recurrent thrombosis is a common and severe complication in patients with PVT and MPN. Mortality is primarily related to the underlying MPN and not to complications of portal hypertension.