label: Abnormal portal venous system morphology
label_lc: abnormal portal venous system morphology
description: "Any structural anomaly of the portal venous system, which comprises all of the veins draining the abdominal part of the digestive tract, including the lower esophagus but excluding the lower anal canal. The portal vein conveys blood from viscera and ramifies like an artery at the liver, ending at the sinusoids. Tributaries of the portal vein, which make up the portal venous system, are the splenic, superior mesenteric, left gastric, right gastric, paraumbilical, and cystic veins."