EASL Clinical Practice Guidelines: Vascular diseases of the liver.

Vascular disorders of the liver, although affecting less than 5/10,000 patients, collectively account for a number of rare conditions that represent an important health problem worldwide in the field of liver diseases. A common characteristic of most of these disorders is that they can cause non-cirrhotic portal hypertension with an ensuing high morbidity and mortality. In addition, special relevance addresses the fact that patients are usually young with an otherwise normal life expectancy that may be markedly shortened if they are not adequately managed. Advances in the knowledge of vascular liver disorders are hampered by the small number of cases and a limited number of studies assessing natural history, pathophysiology or therapy. However, in recent years, interest for these disorders has increased as reflected in the rise in the number of publications on this topic. In addition, EASL has encouraged this increased interest by sponsoring a monothematic conference in June 2012 in Tallinn on vascular disorders of the liver, and by proposing an EASL clinical practice guidelines on the issue. These guidelines will not cover all possible vascular disorders of the liver but are mainly based on the subjects discussed during the monothematic conference; Budd-Chiari syndrome, non-cirrhotic portal vein thrombosis, idiopathic portal hypertension, sinusoidal obstruction syndrome, hepatic vascular malformations in hereditary haemorrhagic telangiectasia and portal vein thrombosis in cirrhosis. Guidelines have been written according to published studies retrieved from Pubmed. The evidence and recommendations have been graded according to the Grading of Recommendations Assessment Development and Evaluation (GRADE) system. The strength of evidence has been classified into three levels: high (A), moderate (B) or low quality (C), while the grade of recommendation in two levels: strong (1) or weak (2) (Table 1). The higher the quality of the evidence, the more likely a strong recommendation is warranted. Where no clear evidence existed, recommendations were based on agreed opinions of the writing committee members.