Developing a Prognostic Score to Predict Graft and Patient Survival after Orthotopic Liver Transplantation (OLT)

Abstract

Background: The current liver organ allocation system strongly favors organ distribution to critically ill recipients who exhibit poor survival outcomes following OLT.A severely limited organ resource, increasing wait list deaths, and rising numbers of critically ill recipients mandate an organ allocation model that balances disease severity with survival outcomes. Such goals can be realized only through the development of prognostic score that predict graft survival following OLT. We developed a novel prognostic score that predicts graft and patient survival outcomes after OLT Methods: We reviewed all adult liver transplants from 1990 to 2011. This data were entered prospectively into a web-based database. The following variables were analyzed using a Cox proportional hazards model to determine predictors of survival:donor age, sex, BMI, and donor risk index (DRI), recipient age, sex, diagnosis, number of re-transplants, combined transplants, MELD, Child score, pre-transplant need for dialysis, intraoperative blood loss, the use of cell saver, warm and cold ischemia time, blood transfusion during or 24hours post transplant and INR/total bilirubin levels at baseline and in the first week after transplant Results: 716 patients were analyzed. Median DRI was 1.52(1.3-1.8), recipient age 57(50-63) years, MELD 20(18-27), warm ischemia time 1.1(1-1.3) hours, cold ischemia time 8.7(6.7-11.3) hours, blood loss 1600(900-2700)ml.HCV as an indication for transplant was in 34% and HCC in 20%. Five-year graft and patient survival were both around 60% with a median overall survival of about 10 years. The following variables were found to contribute significantly to the prognostic model: cold (>10 hours) and warm (>1.5 hours) ischemia time, blood loss(>3000ml), MELD (>30), DRI and the diagnosis of HCV. Prognostic score was generated based on graft survival (Table 1)All these variables were binary (0,1) except for DRI. Risk score results divided patients into 3 groups:Low risk < -1, intermediate risk -1-0, and high risk >0. The high-risk group had almost half the median survival of the overall cohort(Figure 1)[Figure 1]Conclusion: This new prognostic score was generated from our data and needs to be validated.If validated, such a tool can potentially be used to determine prognosis in the early postoperative period and can also serve as an early surrogate marker for interventional studies