Small-for-size grafts in living-related liver transplantation

The problems associated with small-for-size grafts in living-related liver transplantation are not fully understood.

A consecutive series of 79 patients underwent 80 living-related liver transplantation procedures, including one retransplant, at the University of Tokyo from January 1996 to January 2000. They were divided into two groups by graft size: graft weight/recipient standard liver volume ratios of 40% or less (n = 24), and more than 40% (n = 56). Preoperative status, mortality, morbidity, duration of hospital stay, and postoperative graft function were examined and compared between the groups.

The rate of patients who were restricted to the intensive care unit preoperatively was comparable between the groups (33% versus 21%, p = 0.27). The mean standard liver volume ratios were 37% in the small graft group and 84% in the large group. Survival rates were 80% (5 of 24) for the small graft group, which was significantly lower than that for the large group (96%, 54 of 56, p = 0.02). The rate of acute rejection was comparable between the groups (33% versus 43%, p = 0.47). Vascular complication was observed in 17% of the small graft group patients and 23% of the large group (p = 0.77). No difference was observed in the frequency of bile leakage or bile duct stenosis (25% versus 21%, p=0.77). Hyper-bilirubinemia and elongation of prothrombin time persisted longer in the small graft group than in the large group (p < 0.0001 for both).

Our surgical results may suggest that a graft weight ratio of 40% or less provides a lower chance of survival after living-related liver transplantation.