Medical and Surgical Weight Loss as a Pathway to Renal Transplant Listing

Abstract

Purpose: Severe obesity is a barrier to listing for kidney transplantation due to concern for poor outcomes. This study aims to compare bariatric surgery with medical weight loss as a means of achieving weight loss and subsequent listing for renal transplant. We hypothesize that bariatric surgery will induce greater frequency of listing for transplant within 18 months of study initiation.

Materials and methods: We performed a randomized study of metabolic bariatric surgery (MBS) vs medical weight loss (MM) in patients on dialysis with a body mass index (BMI) of 40-55 kg/m². The primary outcome was suitability for renal transplant within 18 months of initiating treatment. Secondary outcomes included weight loss, mortality, and complications.

Results: Twenty patients enrolled, only 9 (5 MBS, 4 MM) received treatment. Treated groups did not differ in age, gender, or race (P ≥ .44). There was no statistically significant difference in the primary endpoint: 2 MBS (40%) and 1 MM (25%) listed for transplant ≤18 months (P = 1.00). With additional time, 100% MBS and 25% MM patients achieved listing status (P = .048); 100% of MBS and 0 MM received kidney transplants to date (P = .008). Weight, weight loss, and BMI trajectories differed between the groups (P ≤ .002). One death from COVID-19 occurred in the MM group, and 1 MBS patient had a myocardial infarction 3.75 years after baseline evaluation.

Conclusion: These results suggest MBS is superior to MM in achieving weight loss prior to listing for kidney transplantation. Larger studies are needed to ensure the safety profile is acceptable in patients with ESRD undergoing bariatric surgery.

Keywords: bariatric surgery; end stage renal disease; medical weight loss; renal transplant.