Ex Vivo Surgical Removal Versus Conservative Management of Small Asymptomatic Kidney Stones in Living Donors and Long-term Kidney Transplant Outcomes.

Background: Donors with small asymptomatic kidney stones have been increasingly accepted because of organ shortages and advances in endoscopic urology. This study aims to evaluate and compare long-term living-donor kidney transplant outcomes following ex vivo surgical removal versus conservative management of donors' gifted asymptomatic stones.

Methods: Between January 2007 and December 2021, 119 kidney transplant recipients received stone-bearing kidneys, divided into the removal group (N = 63) and observation group (N = 56). We evaluated posttransplant stone events, urinary infections, kidney function, delayed graft function, length of hospital stay, and survival outcomes.

Results: After a median follow-up of 75.5 mo, the removal group had a 10.9% lower absolute incidence of stone events (7/56 [12.5%] versus 1/63 [1.6%]; hazard ratio, 0.08; 95% confidence interval, 0.01-0.77) and a 14.3% lower absolute incidence of urinary infections (16/56 [28.6%] versus 9/63 [14.3%]; hazard ratio, 0.42; 95% confidence interval, 0.19-0.95) than the observation group. The removal group also showed superior kidney graft function. The 2 groups had comparable length of hospital stay (11.0 versus 12.0 d; P = 0.297) and exhibited similar delayed graft function incidence (1/56 [1.8%] versus 2/63 [3.2%]; P = 1.000) and urinary stricture incidence (1/56 [1.8%] versus 3/63 [4.8%]; P = 0.621). Graft survival (P = 0.350) and patient survival (P = 0.260) were comparable between 2 groups. Subgroup analyses in recipients who received kidneys with stones <4 mm also reported similar results.

Conclusions: Ex vivo surgical removal might outperform conservative management for donors' gifted asymptomatic kidney stones, improving long-term transplant outcomes and reducing stone events without increasing perioperative complications, even for stones <4 mm.