Portal Vein Thrombosis Relevance on Liver Cirrhosis: Italian Venous Thrombotic Events Registry

The portal vein thrombosis (PVT) can complicate medical conditions like liver cirrhosis (LC), neoplasms, myeloproliferative diseases, thrombophilic genotypes, infections, inflammatory diseases, trauma and surgery. LC is an important predisposing disease and is responsible for about 20% of all cases. However, data regarding the PVT in cirrhosis are insufficient.

Early studies have shown that, in absence of hepatocellular carcinoma (HCC), the PVT can occur in approximately 10% of cirrhotic patients.

Most of studies are in support of a prevalence between 5 and 20% of patients with LC. A study in transplant recipients, has documented that in variable etiology cirrhosis, the PVT was present in 15.7% of patients, a higher percentage was found in patients with liver cancer (34.8%), while primary biliary cirrhosis (7.9%) and sclerosing cholangitis (3.6%) are less frequently complicated by PVT.

The PVT development is due to stagnation in the portal circulation, but alterations in the sense of inherited or acquired pro-coagulant may favor its appearance.

The causal association of PVT with bleeding and bowel infarction suggests that the PVT may reduce survival in cirrhosis, but data are lacking on this issue. It is also not known whether asymptomatic patients with PVT have a different survival compared to cirrhotic patients without PVT. Further studies should be conducted to clarify this issue.

Likewise, prospective studies are needed to better identify risk factors predisposing to PVT in LC patients as well as to clarify the relationship between cirrhosis severity and PVT. The impact of PVT on the natural history of cirrhosis is an issue today still debated.

The PVT not only favour life-threatening complications (gastrointestinal bleeding and mesenteric thrombosis) but could also contribute to a deterioration of liver function by reducing portal flow. Obtaining such information would be of crucial importance considering that the evidence of increased mortality related to PVT in liver cirrhosis may indicate the need for randomized controlled trials to clarify the potential effectiveness of anticoagulant therapy to improve the survival.

To this purpose it's proposed to establish an Italian register of patients with cirrhosis. In the second phase of the project is planned a 2-years follow-up program in order to assess whether the PVT be an additional risk factor for mortality or deterioration of the natural history in patients with cirrhosis.