Perioperative Challenges in Patients Transplanted with Livers from Extreme Obese Donors

The combination of rising rates of obesity and the shortage of deceased donor livers have forced the consideration of marginal liver donors in terms of body mass index (BMI) for liver transplantation (LT). To date, there are still conflicting data on the impact of donor obesity on post-LT outcomes. We analyzed all patients undergoing LT alone in the United States (US) from October 2005 through December 2019 using the United Network of Organ Sharing (UNOS) data set. We categorized donor BMI >40 kg/m(2) as extremely obese (EO). Primary endpoints included 30-day perioperative mortality and early graft loss (EGL) within 7 days. A subgroup analysis was performed for the EO donor group to assess how macrovesicular steatosis (MaS) >30% affects 30-day mortality and EGL within 7 days. A total of 72,616 patients underwent LT during the study period. The 30-day perioperative mortality was significantly higher in the EO donor group (P = 0.02). On multivariate analysis, recipients undergoing LT with EO donors had a 38% higher 30-day mortality risk (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.21-1.69) and 53% increased risk of EGL (OR, 1.53; 95% CI, 1.22-1.90). MaS >30% was independently associated with a 2-fold increased risk of 30-day mortality (P = 0.003) and 3.5-fold increased risk of EGL within 7 days (P < 0.001). The impact of MaS >30% in EGL was 2-fold for all patients transplanted during the study period compared with 3.5-fold in the EO donor group. There is an increased risk of EGL and 30-day perioperative mortality in recipients transplanted with EO donors. Future studies are warranted in morbid and super obese donors to assess the possible effect of obesity-related proinflammatory factors in EGL.

Automated summary

Obesity in liver donors, particularly extremely obese donors and donors with macrovesicular steatosis (MaS >30%), may increase the risk of 30-day mortality and early graft loss in liver transplant recipients. Future studies are needed to evaluate the impact of obesity-related proinflammatory factors on early graft loss.