Defining the complexity of liver transplant: the development of a scoring system to assess recipient risk

Abstract

Introduction: Patients undergoing liver transplantation (LT) are routinely assessed for surgical difficulty, but the predictability of these assessments is unreliable and are unquantified. We aimed to identify and quantify risk factors for surgical complexity in LT to inform decision making and assist in peri-operative planning. Methodology: We retrospectively examined all adult liver transplants performed at a single centre between 2012 and 2023. Surgical difficulty was defined by three surrogate measures; operating time, estimated blood loss, and intraoperative complications. Patients were allocated points based on their percentiles for each surrogate and stratified into low (LD), intermediate (ID) and high (HD) difficulty cohorts. Cohorts were compared based on demographic, biochemical, surgical and radiological data. Univariate and multivariate logistic regression was performed to calculated odds ratios (OR) with p<0.05 considered statistically significant. Results: A total of 771 transplants were included in the study (LR; n=225, IR; n=346, HR; n=200). Patients in the HD cohort were associated with worse overall survival (OS; HD 85.5% vs ID 93.7% vs LD 96.4%, p<0.001) and graft failure (GF; HD 6.5% vs ID 2.0% vs LD 0.9%, p<0.001) at 1-year as well as longer hospital length of stay and surgical complications. Factors predictive of surgical difficulty were multiple prior abdominal surgical procedures (>1, OR 1.94, p<0.05), prior open hepatobiliary surgery (OR 3.86, p<0.05), re-transplantation (OR 5.89, p<0.05) and prior spontaneous bacterial peritonitis (OR 3.04, p<0.05) Conclusions: We identified four key variables associated with significant risk for surgical complexity in LT. These risk factors have been incorporated into a score in a pre-operative setting to adequately inform patient of risks and plan perioperative resources accordingly.