Incidence and mortality rates of splanchnic vein thrombosis

Thrombosis of splanchnic veins encompasses hepatic (Budd-Chiari syndrome, BCS), portal, mesenteric, and splenic veins. In the general population, splanchnic vein thrombosis (SVT) is rare. BCS and portal vein thrombosis (PVT) are listed in Orphanet (Orpha 131 and Orpha 854, respectively) (1). However, there is no internationally accepted definition of rare disease, and the prevalence rate employed in national legislations varies from less than 200,000 (approximately 1 in 1,500 individuals) in the United States to 1 in 10,000 individuals in Australia and Taiwan (2,3). In Europe, a disease is defined as rare when it affects less than 1 in 2,000 individuals (4).