Right Posterior Sector Research Articles

Selection of a right posterior sector graft for living donor liver transplantation

Right posterior sector (RPS) grafts have been used to overcome graft size discrepancies, the major concern of living donor liver transplantation. Previous studies have reported the volumetry-based selection of RPS grafts without anatomical exclusion. We reviewed our data and established selection criteria for RPS grafts. The procurement of RPS grafts [conventional (n = 3) and extended (n = 5)] was performed for 8 of 429 recipients at our center. Extended RPS grafts contained the drainage area of the right hepatic vein. The mean graft weight (GW) according to 3-dimensional computed tomography volumetry was 488 g, and the GW/standard liver weight (SLW) ratio was 42.6%. The mean actual GW was 437 g, and the GW/SLW ratio was 38.4%. One donor exhibited standard bifurcation of the right portal vein (PV) and the left PV, and 2 donors exhibited trifurcation of the left PV, the right anterior portal vein (APV), and the posterior PV. The remaining 5 donors exhibited APV branching from the left PV, which is the most suitable anatomy for RPS grafts. Two recipients died of sepsis or small-for-size graft syndrome. One underwent retransplantation because of an intractable bile leak and fibrosing cholestatic hepatitis. Intractable bile duct (BD) stenosis developed in 4 of the 6 survivors. In conclusion, with the significant complications and potential concerns associated with RPS grafts, these grafts should be used very rarely and with extreme caution. Donors with the standard bifurcation of the PV and the posterior BD running through the dorsal side of the posterior PV are not suitable candidates for RPS grafts. Extended RPS graft procurement is recommended for easier parenchymal transection.

Volumetry-based selection of right posterior sector grafts for adult living donor liver transplantation

To determine the feasibility of volumetric criteria without anatomic exclusion for the selection of right posterior sector (RPS) grafts for adult-to-adult living donor liver transplantation (LDLT), we reviewed and compared our transplant data for RPS grafts and right lobe (RL) grafts. Between January 2008 and September 2010, adult-to-adult LDLT was performed 65 times at our institute; 13 of the procedures (20%) were performed with RPS grafts [the posterior sector (PS) group], and 39 (60%) were performed with RL grafts (the RL group). The volumetry of the 13 RPS donor livers showed that the RPS volume was 39.8% ± 7.6% of the total liver volume. Ten of the 13 donors had to donate RPS grafts because the left liver volume was inadequate. All donor procedures were performed successfully, and all donors recovered from hepatectomy. However, longer operative times were required for the procurement of RPS grafts versus RL grafts (418 ± 40 versus 345 ± 48 minutes, P < 0.001). The postoperative recovery of liver function was smoother for the donors of the PS group versus the donors of the RL group. The RPS grafts had significantly smaller hepatic artery and bile duct openings than the RL grafts. All recipients with RPS grafts survived LDLT. No recipients experienced vascular graft complications or small-for-size graft dysfunction. There were no significant differences in the incidence of posttransplant complications between the donors and recipients of the PS and RL groups. The 3-year graft survival rates were favorable in both groups (100% in the PS group versus 91% in the RL group). In conclusion, the selection of RPS grafts by volume criteria is a feasible strategy for an adult-to-adult LDLT program.

Adult-to-adult live-donor liver transplantation: the current status

Adult-to-adult live-donor liver transplantation (ALDLT) has emerged successfully to partially relieve the refractory shortage of deceased donor grafts caused by the increasing demands of patients with endstage liver diseases. Following the first successful live-donor liver transplantation (LDLT) for a child with biliary atresia in 1989, further extension of the technique, using left-lobe liver grafts for LDLT for large adolescents and adults, has resulted in satisfactory graft and patient survival outcomes. However, small-for-size syndrome may occur in some patients with large body size, and in those with acute-on-chronic liver failure or severe portal hypertension. To overcome the problem of graft-to-body-size mismatch, ALDLT, using a right-lobe liver graft was developed. Although routine inclusion of the middle hepatic vein (MHV) in the right-lobe liver graft is still controversial, the importance of providing good venous drainage for the right anterior sector to ensure better early graft function has gained wide recognition. Preservation of the MHV in the donor is intuitively considered important in reducing the donor risk. However, there are scarce data supporting the contention that postoperative complication is related to the absence of the MHV in the left-liver remnant. Duct-to-duct biliary reconstruction has potential advantages over hepaticojejunostomy, and has become the preferred technique in ALDLT. However, biliary complications, especially biliary strictures on long-term follow-up, occur in about 30% of the recipients. The potential beneficial effect of internal or external biliary drainage in reducing the biliary complication rate after duct-to-duct biliary reconstruction in ALDLT also remains controversial. Dual-liver grafts and right-posterior sector grafts have been used in ALDLT, and are reported to result in satisfactory survival outcomes at selected transplant centers. There is no strong evidence supporting the postulate that patients with hepatitis C infection have an inferior survival outcome after ALDLT when compared with recipients of a deceased-donor liver transplant. ALDLT has contributed to satisfactory survival outcomes in patients with hepatocellular carcinoma (HCC). It allows early surgery for the patients and eliminates the uncertainty of prolonged waiting for a deceased-donor liver graft, and the risks of dropout related to disease progression. The exact selection criteria of patients with HCC for ALDLT have yet to be defined.