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.