Is there a role for timely diagnosis and early anticoagulant treatment of portal vein thrombosis in patients with liver cirrhosis?

Portal vein thrombosis (PVT) is a rather uncommon disease, although the growing use of non-invasive diagnostic techniques has increased the frequency with which it is diagnosed. PVT can occur in patients with malignancies, myeloproliferative disorders (MPD) and liver cirrhosis, but several other conditions may also act as predisposing factors [1]. In Internal and Emergency Medicine, Fimognari and Violi have reported an elegant overview of the literature in the specific setting of PVT related to liver cirrhosis. The authors have analyzed available information on the pathogenesis, clinical presentation, diagnosis and treatment of PVT in liver cirrhosis and have raised a number of critical clinical questions that remain to be answered [2]. Unfortunately, as the authors have underlined, information on PVT is scant. Available studies are mainly represented by case series with a small sample size and, thus, in most circumstances current knowledge on PVT is not based on firm scientific evidences. Some open issues are particularly critical in the subgroup of patients with PVT and underlying liver cirrhosis and we believe that some of these issues request some urgent answers. First, is PVT relevant to the prognosis of patients with liver cirrhosis? As discussed by Fimognari and Violi [2], PVT is a common complication of liver cirrhosis, occurring in as many as 10–20% of affected patients. There is no evidence to suggest that PVT provokes deterioration of liver function, but several authors have reported an increased risk of variceal haemorrhage [3–6]. This is entirely plausible since PVT provokes a sudden worsening of portal hypertension and thus also a worsening of the severity of varices. This aspect poses the second critical question: could early and effective treatment of PVT reduce the subsequent incidence of variceal bleeding, thus improving the outcome in these patients? Antithrombotic therapies, in particular unfractionated heparin, low molecular weight heparin and vitamin K antagonists, are commonly prescribed to treat PVT in other patients groups, although there are no adequate clinical trials that have clearly demonstrated the efficacy and safety of any of these treatments [2]. In patients with PVT and liver cirrhosis, the use of antithrombotic drugs is much more limited because the risk of bleeding is generally conceived to exceed the risk of thrombus extension or recurrence. However, this unfavourable balance may not apply to all patients with cirrhosis, but perhaps only to patients with more severe portal hypertension at baseline. There is some little evidence suggesting that antithrombotic therapy effectively induces recanalization of the portal vein without increasing the risk of bleeding in these patients [7]. Thus, we may hypothesize that at least some patients with liver cirrhosis and PVT, in particular those with less severe portal hypertension, may actually benefit from anticoagulant treatment, in particular if started early. A timely start of anticoagulant treatment could favour recanalization and reduce the subsequent risk of variceal bleeding. To prove this hypothesis, a more timely diagnosis of PVT is needed. Unfortunately, PVT diagnosis frequently occurs late because PVT is often asymptomatic or, more likely, because many of its symptoms are non specific and thus are not recognized. It becomes crucial to increase W. Ageno M. Galli A. Squizzato F. Dentali Department of Clinical Medicine, University of Insubria, Varese, Italy