Weight Loss Surgery Increases Kidney Transplant Rates in Patients With Renal Failure and Obesity

Abstract

Objective: To describe the outcomes of kidney transplant (KT) candidates with obesity undergoing sleeve gastrectomy (SG) to meet the criteria for KT.

Methods: Retrospective analysis was conducted of electronic medical records of KT candidates with obesity (body mass index >35 kg/m²) who underwent SG in our institution. Weight loss, adverse health events, and the listing and transplant rates were abstracted and compared with the nonsurgical cohort.

Results: The SG was performed in 54 patients; 50 patients did not have surgery. Baseline demographic characteristics were comparable at the time of evaluation. Mean body mass index ± SD of the SG group was 41.7±3.6 kg/m² at baseline (vs 41.5±4.3 kg/m² for nonsurgical controls); at 2 and 12 months after SG, it was 36.4±4.1 kg/m² and 32.6±4.0 kg/m² (P<.01 for both). In the median follow-up time of 15.5 months (interquartile range, 6.4 to 23.9 months), SG was followed by active listing (37/54 people), and 20 of 54 received KT during a median follow-up time of 20.9 months (interquartile range, 14.7 to 28.3 months) after SG. In contrast, 14 of 50 patients in the nonsurgical cohort were listed, and 5 received a KT (P<.01). Three patients (5.6%) experienced surgical complications. There was no difference in overall hospitalization rates and adverse health outcomes, but the SG cohort experienced a higher risk of clinically significant functional decline.

Conclusion: In KT candidates with obesity, SG appears to be effective, with 37% of patients undergoing KT during the next 18 months (P<.01). Further research is needed to confirm and to improve the safety and efficacy of SG for patients with obesity seeking a KT.

Figure 1:. Change in total weight from time of evaluation to last follow-up.

Prior to surgery all patients are considered to be part of the ‘No SG’ group. The effect of surgery is then a change in the slope for those that received surgery compared to that of the overall cohort. For visual demonstration, patients’ timelines were centered on either the time of bariatric surgery for those who received surgery or 130 days post-evaluation for those who didn’t receive bariatric surgery. A: All patients B: Patients with type 2 diabetes versus no type 2 diabetes C: Patients on dialysis versus no dialysis

Figure 2:. Time to adverse health outcomes from evaluation to the last follow-up.

Incidence plots are predicted curves from Cox regression for a hypothetical patient who received surgery at 90 days post-evaluation. These are used as an alternative to the standard Kaplan-Meier plot, given that SG status is not defined at baseline but changes over time. A: Time to waitlist for a kidney transplant. Incidence is given as curves predicted from a Cox regression model that uses SG status as a time-dependent covariate. B: Time to first hospitalization C: Time to the first major adverse cardiovascular event from evaluation to the last follow-up D: Time to first dialysis complication from evaluation to the last follow-up