Lower Limit 4 the Graft-to-Recipient Weight Ratio Can Be Safely Reduced to 0.6% in Adult-to-Adult Living Donor Liver Transplantation in Combination with Portal Pressure Control

Introduction. The goal of this study was to examine whether the lower limit of the graft-to-recipient weight ratio (GRWR) can be safely reduced to make better use of a left-lobe graft in adult-to-adult living donor liver transplantation (LDLT) in combination with portal pressure control. Patients and methods. Beginning in December 2007, our institution actively selected left-lobe grafts for use in liver transplantation seeking to minimize the risks to healthy donors. We gradually decreased the lower limit of the GRWR to preferentially select a left-lobe over a right-lobe graft: from >= 0.7% beginning in December 2007 to >= 0.6% beginning in April 2009. A portal pressure control program, targeting final portal pressures below 15 mm Hg, was also introduced to overcome small-for-size graft problems. The ratio of left-lobe grafts among all adult-to-adult LDLT grafts and the donor complication rate (defined as Clavien grade >= III, excluding wound infection) were compared between two time periods: June 1999 to November 2007 (period 1, n = 541) and December 2007 to February 2010 (period 2, n = 119). Overall survival rates were also compared between those recipients of a GRWR < 0.8% and those with a GRWR 0.8% in 198 recipients who underwent LDLT at our institution between April 2006 and February 2010. Results. Left-lobe grafts use increased from period 1 (65/541 recipients; 12.0%) to period 2 (50/119 recipients; 42.0%; P < .001). The donor complication rate tended to decrease from 13.8% in period 1 to 9.3% in period 2 (P = .115). The overall survival rate in 52 recipients with a GRWR < 0.8% did not differ from that in 146 recipients with a GRWR >= 0.8%. Conclusions. The lower limit of the GRWR can be safely reduced to 0.6% in adult-to-adult LDLT in combination with portal pressure control.