An unusual presentation of type II Abernethy malformation

Abernethy malformation is a rare anomaly of the splanchnic venous system. We report a case of an unusual portosystemic shunt via a dilated inferior mesenteric vein. A 20-year-old woman was referred to our hospital with complains of nonspecific abdominal pain for almost 3 years and hematochezia since 15 months old. Computed tomography and further transhepatic splenoportography revealed a hypoplastic portal vein and a giant inferior mesenteric vein, via which part of the portal venous blood drained into the inferior vena cava. The patient underwent a surgical ligation of the portocaval shunt and recovered well. We believe that this is the first case of type II Abernethy malformation presenting as a portosystemic shunt via the giant inferior mesenteric vein.