Anatomy and clinical importance of cholecystic venous drainage: helical CT observations during injection of contrast medium into the cholecystic artery

The purpose of this study was to use helical CT to elucidate the anatomy and clinical importance of cholecystic venous drainage. We performed helical CT of the upper abdomen during injection of contrast medium through a superselectively catheterized cholecystic artery (cholecystic artery CT) in 28 patients, all of whom were surgical candidates for suspected hepatobiliary abnormality. In nine of these patients, CT during arterial portography (CTAP) was also performed. Cholecystic venous blood most frequently entered peripheral portal branches of hepatic segment V (27 of 28 patients, 96%) and segment IV (26 of 28, 93%). In order of decreasing frequency, cholecystic venous blood also drained to segments I, VI, VIII, III, and VII. Cholecystic venous blood subsequently drained into the middle hepatic vein (21 of 28, 75%) or right hepatic vein (20 of 28, 71%). In two patients with adenocarcinoma involving the gallbladder associated with multiple liver metastases, cholecystic venous drainage was seen around each metastatic focus. In the nine patients in whom both cholecystic artery CT and CTAP were performed, nontumorous portal perfusion defects were attributable to cholecystic venous drainage. Recognition of cholecystic venous drainage as a possible pathway for spread of disease from the gallbladder to the liver and also as one of the causes of non-tumorous portal perfusion defects seen on CTAP is important.