[S4 S5 subsegmentectomy of the liver for gallbladder carcinoma]

Although innovations have occurred in imaging technology and surgical techniques, carcinoma of the gall-bladder still has a poor prognosis. Since the 1960s, we have performed extended cholecystectomy in patients with gallbladder cancer. Extended cholecystectomy is a safe and common treatment for advanced cancer, but the extent of necessary hepatic resection has not been established. In 2000, we reported that the gallbladder veins infused into the intrahepatic portal venous branch, mostly at P4 and P5(96.7%). Based on those results, we now perform resection of the lower part of segment 4(S4a) and segment 5 for advanced cancer with subserosal invasion and/or negligible direct invasion to the parenchyma of the liver. S4aS5 subsegmentectomy is thought to have a clear advantage over extended surgical margins. This procedure can remove almost all the area perfused by the gallbladder veins and as a results, it may also remove latent and occult metastatic foci. The steps in the procedure are as follows: 1) lymph nodes cleaning of the posterior of the pancreas head; 2) skeletonization of the hepatoduodenal ligament; 3) identification and ligation of the lower branch of P4; 4) identification of the boundary between the anterior and posterior segment; and 5) hepatic resection with the plate of the gallbladder. Since 1991, we have performed S4aS5 subsegmentectomy in 12 patients with gallbladder cancer. Although the follow-up period is short, it is thought that the outcome of this procedure is better than that of extended cholecystectomy because of the low mortality and morbidity rates.