Effect of Body Mass Index on Complications and Survival After Living Donor Liver Transplantation

The influence of obesity on postoperative outcomes remains controversial. We evaluated the relationship between preoperative body mass index and perioperative and postoperative outcomes in adult recipients of living donor liver transplant.

We retrospectively studied 225 adult patients who underwent living donor liver transplant between November 2019 and June 2024 and grouped patients by preoperative body mass index (calculated as weight in kilograms divided by height in meters squared) into 4 groups. Demographic data, comorbidities, operative parameters, complication rates, and survival outcomes were analyzed across groups. We used multivariable Cox regression analysis to assess independent predictors of mortality.

Although Model for End-Stage Liver Disease scores, operative time, and hospital stay did not differ significantly among groups, higher body mass index was associated with significantly increased early postoperative complications (P = .018). Logistic regression revealed early complications as an independent predictor of mortality (odds ratio of ≈9, P < .001). Overall survival differed significantly across body mass index categories (P = .007), with poorest outcomes in morbidly obese patients (body mass index ≥ 40). Cox regression confirmed that obesity (body mass index 35-39.9) was an independent predictor of reduced long-term survival (hazard ratio = 1.65; 95% CI, 1.01-2.70; P = .045), whereas morbid obesity showed a nonsignificant trend toward higher risk. Diabetes, cardiovascular disease, and low graft-to-recipient body weight ratio were also more common in higher body mass index groups and contributed to increased mortality risk.

Elevated body mass index was associated with increased early postoperative risk, particularly in the obese group, with reduced long-term survival posttransplant. These associations remained significant after adjustment for major clinical covariates. Presence of comorbidities and reduced graft-to-recipient weight ratio further compounded risk. Comprehensive preoperative evaluation and individualized management, including metabolic optimization and prehabilitation, may help improve outcomes in this high-risk population.