Pitfall of Right Lateral Sector Graft Procurement

Abstract

Selection of a right lateral sector graft for adult-to-adult living donor liver transplantation (LDLT) has become feasible (1, 2). Herein, a case of right lateral sector graft procurement for liver transplantation is presented in which technical difficulties were encountered because of an anomaly of the right posterior hepatic artery. A 21-year-old male patient volunteered to serve as a live donor for liver transplantation for his brother who was suffering from fulminant hepatitis. A volumetric analysis revealed that only a right lateral sector graft would be suitable (3). Preoperative computed tomography revealed a supraportal right posterior hepatic artery, i.e., the right posterior hepatic artery running cranially over the right anterior portal vein (Fig. 1A, B), and the vascular anomaly was confirmed intraoperatively (Fig. 1C). Isolation of the right posterior hepatic artery was difficult during procurement of the graft because it ran between the right posterior portal vein and the posterior bile duct. Furthermore, the distal part of the right posterior hepatic artery was very thin, and the dissection between the perivascular tissue and the distal part of the right posterior hepatic artery was technically difficult, and had risk of injury by approach from the hepatic hilum.FIGURE 1: A, computed tomographic image showing the right posterior hepatic artery running cranially over the right anterior portal vein, i.e., supraportal right posterior hepatic artery (arrowhead). B, the three-dimensional reconstruction image of the computed tomography. The view is from the caudal side of the patient similar to the intraoperative view. The arrowhead indicates the supraportal right posterior hepatic artery. C, the intraoperative findings confirmed the preoperative imaging findings. The arrowhead indicates the supraportal right posterior hepatic artery. RHA, right hepatic artery; RAHA, right anterior hepatic artery; RPHA, right posterior hepatic artery; RPV, right portal vein; RAPV, right anterior portal vein; RPPV, right posterior portal vein.Therefore, after hilar dissection, the hepatic parenchymal transection was completed. At this stage, the right lateral sector was connected only via the posterior portal pedicle and the right hepatic vein. Under intraoperative cholangiography, the posterior duct was carefully divided. Probably because the dissection between the perivascular tissue and the distal part of the right posterior hepatic artery was insufficient, during division of the posterior duct, the distal part of the right posterior hepatic artery was injured. The right hepatic artery was temporarily clamped and the right lateral sector graft was procured by dividing the right posterior hepatic artery, the posterior portal vein, and the right hepatic vein, in that order. The right posterior hepatic artery was divided at the peripheral side after it had crossed the right anterior portal vein. Implantation of the right lateral sector graft was successfully carried out. The only problem was that the blood flow of the initial end-to-end anastomosis between the recipient hepatic artery and donor right posterior hepatic artery was insufficient. Therefore, a re-anastomosis was performed after trimming the anastomosis line and finally sufficient blood flow was obtained. The postoperative course was uneventful in both the donor and the recipient. Five hundred eleven LDLTs were performed at the institution between January 1996 and August 2013. During this period, a right lateral sector graft was procured in 27 cases (5.3%). The case presented herein was the only one with this type of vascular anomaly. Yoshioka et al. have reported encountering this type of anomaly during extended left hepatectomy for cholangiocarcinoma (4). The reported incidence of supraportal right posterior hepatic artery is 5.4%. The reported incidence of infraportal hepatic artery for segment 6 and supraportal hepatic artery for segment 7, i.e., the combined type of anomaly, is 6.4%. Because the right anterior portal vein cannot be cut during a donor operation, the difficulty posed by this anomaly is even greater during right lateral sector graft procurement than during surgery for cholangiocarcinoma. In cases with the combined type of anomaly, reconstruction of the right posterior hepatic artery is necessary. This case underscores the importance of paying attention to the course of the right posterior hepatic artery during right lateral sector graft procurement. Because supraportal right posterior hepatic artery can cause accidental arterial injury, complete transection before cutting of the posterior portal pedicle is recommended. Takashi Kokudo 1 Kiyoshi Hasegawa1 Yasuhiko Sugawara1 Norihiro Kokudo1,2 1Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division Department of Surgery Graduate School of Medicine The University of Tokyo Tokyo, Japan