Individual Surgeon Experience Yields Bimodal Effects on Patient Outcomes After Deceased-Donor Liver Transplant: Results of a Quantile Regression for Survival Data

Objectives: Data on the relevance of surgeon experience in liver transplant procedures are scarce. In this study, we evaluated the effects of individual surgeon experience on survival outcomes after deceased-donor liver transplant. Materials and Methods: In this retrospective analysis of 1193 liver transplant procedures, quantile regression for survival data was performed to assess the effects of surgeon experience. Conditional quantiles of mortality and graft loss were set as primary and secondary outcome measures, respectively, which were categorized as early, midterm, and late. Results: Greater experience of a surgeon performing hepatectomy increased the risk of early mortality (P = .005) and graft loss (P = .025) when the recipient Model for End-Stage Liver Disease was 25 and the donor Model for End-Stage Liver Disease was 1600. In conventional transplant procedures, greater experience of surgeon performing hepatectomy additionally increased the risk of midterm mortality (P = .027) and graft loss (P = .046). Conversely, a graft implant procedure performed by a more experienced surgeon was associated with better early, midterm, and late outcomes after conventional transplants (all P < .037) and reduced the risk of early graft loss when the donor Model for End-Stage Liver Disease score was > 1600 (P = .027). Conclusions: Unexpectedly, individual surgeon experience yields bimodal effects on posttransplant outcomes, dependent on the stage of operation, operative technique, severity of recipient status, and transplant risk profile.