ANATOMY AND ETIOLOGY OF EXTRAHEPATIC PORTAL-VEIN OBSTRUCTION IN CHILDREN LEADING TO BLEEDING ESOPHAGEAL-VARICES

BACKGROUND: The cause of extrahepatic portal vein obstruction in child hood is unknown. We investigated the anatomical features of extra hepa tic portal vein obstruction to clarify its cause. STUDY DESIGN: We stu died portal venous anatomy in 10 patients with extrahepatic portal vei n obstruction without hepatic disturbances ranging in age from 1 to 7 years (mean age, 4.2 years) using ultrasonography, portal venography, cholangio-computed tomography, and magnetic resonance imaging. RESULTS : The extrahepatic portal vein was not obliterated, but it crossed ove r the common bile duct from the left to the right side at the cranial level of the pancreas and ran in a cranial direction along the right s ide of the common bile duct or coiled itself around the bile duct. Thu s, the extrahepatic portal rein formed a tortuous eta-shape. CONCLUSIO NS: The portal vein was not obstructed in patients with extrahepatic p ortal vein obstruction but formed a characteristic eta-shape by coding itself around the common bile duct, suggesting that extrahepatic port al vein obstruction has an embryological cause.