Bariatric surgery before and after kidney transplant: a propensity score–matched analysis

Background: Obesity is becoming more prevalent in the end-stage renal disease population. Bariatric surgery (BS) is increasingly considered as an approach to become eligible for kidney transplant (KT) or reduce obesity-related morbidities.

Objectives: To assess the short- and long-term outcomes of patients who underwent both BS and KT and to determine the optimal timing of BS.

Methods: Patients who underwent both KT and BS between January 2000 and December 2020 were included and stratified according to the sequence of the 2 operations. The primary outcomes were patient and graft survival. The secondary outcomes were postoperative complications and efficacy of weight loss.

Results: Twenty-two patients were included in the KT first group and 34 in the BS first group. Death-uncensored graft survival in the KT first group was significantly higher than in the BS first group (90.9% versus 71.4%, P = .009), without significant difference in patient survival and death-censored graft survival (100% versus 90.5%, P = .082; 90.9% versus 81.0%, P = .058). There was no significant difference in 1-year total weight loss (1-yr TWL: median [interquartile range {IQR}], 36.0 [28.0–42.0] kg versus 29.6 [21.5–40.6] kg, P = .424), 1-year percentage of excess weight loss (1-yr %EWL: median [IQR], 74.9 [54.1–99.0] versus 57.9 [47.5–79.4], P = .155), and the incidence of postoperative complications (36.4% versus 50.0%, P = .316) between the KT first and BS first groups.

Conclusion: Both pre- and posttransplant BS are effective and safe. Different conditions of each transplant candidate should be considered in detail to determine the optimal timing of BS.