Expanding the living kidney donor pool: outcomes of robotic donor nephrectomy in obese versus non-obese donors.

BACKGROUND

Robotic donor nephrectomy (RDN) offers a minimally invasive alternative to open and laparoscopic techniques for living kidney donation. As obesity rises among potential donors, data comparing RDN outcomes between non-obese and obese donors remain limited. This study evaluates the safety and feasibility of RDN in obese living kidney donors.

METHODS

A single-center retrospective analysis included 212 consecutive donors who underwent RDN between August 2020 and April 2025; after excluding one donor with incomplete covariate data, 211 (137 low BMI [< 30 kg/m2], 74 high BMI [≥ 30 kg/m2]) formed the analytic cohort. To account for baseline imbalance, the primary between-group comparison used propensity-score overlap weighting, with weighted differences and 95% confidence intervals (CIs) estimated by robust weighted regression.

RESULTS

Low BMI donors were modestly older (46.2 vs. 42.2 years; largest imbalance, standardized mean difference 0.32); overlap weighting reduced all covariate differences to approximately zero. After weighting, operating time was longer in high BMI donors (weighted difference + 15.6 min, 95% CI 6.4-24.8; p < 0.001), whereas estimated blood loss, conversion to open surgery (1.4% vs. 0.7%), complications (2.7% vs. 2.2%; all Clavien-Dindo Grade I), length of stay, and renal function through six months did not differ (all weighted p > 0.10). No perioperative deaths occurred. Exploratory subgroup analyses showed longer operating times for high BMI donors with single renal arteries (p = 0.011) and left nephrectomies (p = 0.024), without differences in blood loss or complications.

CONCLUSION

In a rigorously selected cohort, RDN yielded short-term perioperative and functional outcomes in obese donors comparable to non-obese donors, with only a modest increase in operative time that persisted after overlap weighting. These findings support RDN as one component of responsibly expanding the donor pool; however, short-term parity does not establish long-term donor or recipient safety, and expansion must remain contingent on stringent selection, risk counseling, and structured long-term surveillance.