Identification of new donor variables associated with graft survival in a single-center liver transplant cohort.

We currently face the more widespread use of marginal livers for organ transplantation. Therefore, it is imperative to adequately identify the factors affecting early and late graft survival in that setting. The objective of this study was to determine the donor variables associated with graft survival in the liver transplant program of the University of Montreal. We retrospectively studied the survival of 634 grafts transplanted into 634 recipients between 1990 and 2008. The variables associated with 1- and 5-year graft survival were identified with the Cox proportional hazards regression model. The donor population was characterized by a mean age of 45.24 ± 18.15 years; 52.8% had at least 1 of the currently recognized extended criteria donor factors. The recipients had a mean age of 52.51 ± 10.80 years and a mean Child-Pugh score of 9.58 ± 2.32. Liver grafts were considered inadequate with respect to their gross appearance in 16 cases (2.5%). The 1- and 5-year graft survival rates were 78.7% and 71.1%, respectively. According to a Cox regression multivariate analysis, the independent determining factors associated with graft survival were (1) the graft appearance (P < 0.001 at 1 and 5 years), (2) the donor partial pressure of oxygen/fraction of inspired oxygen ratio (P = 0.005 at 1 year and P < 0.005 at 5 years), and (3) the donor hemoglobin level (P = 0.008 at 1 year and P = 0.005 at 5 years). In conclusion, the gross graft appearance, the presence of donor lung diffusion abnormalities, and the donor hemoglobin levels were significantly associated with graft survival. These observations, if they are confirmed, could improve our ability to select marginal organs.