Splanchnic vein thrombosis (SVT), comprising thromboses in the mesenteric, splenic, or portal veins (with or without hepatic veins), is a relatively uncommon venous thrombotic condition. As such, there are virtually no prospective randomized data on the appropriate therapeutic interventions and outcomes, and most knowledge of this condition comes from retrospective case series, small prospective cohorts, or case reports. That is why the report by Ageno et al1 in this issue of JAMA Internal Medicine that assesses the outcomes of treatment for patients with SVT in the large prospective registry of the International Society on Thrombosis and Hemostasis holds importance. Even though the study is observational, it comprises a large cohort, focuses on therapeutic interventions and outcomes, and has a relatively long follow-up period. The incidence of SVT is estimated to be between 1 and 4 cases per million people.2 The highest reported prevalence, 1%, was determined in an autopsy study3 of Swedish patients, although SVT may not have been suspected during the lives of these patients. The most common underlying conditions associated with SVT are liver disease (cirrhosis), cancer, and idiopathic sources. Many of the latter are often undetected hematologic cancer or hereditary thrombophilia.
Ansell J. The Subtle Benefit of Anticoagulant Therapy for Splanchnic Vein Thrombosis. JAMA Intern Med. 2015;175(9):1481-1482. doi:10.1001/jamainternmed.2015.3196