Risk of Inguinal Hernia Repair Following Laparoscopic Living Donor Nephrectomy: A Population-Based Cohort Study.

Background: A prior study of living kidney donors demonstrated a substantially higher long-term risk of hydrocelectomy among male living kidney donors who underwent laparoscopic nephrectomy compared with nondonors. Given the potential shared anatomical pathways between hydrocele and indirect inguinal hernia formation, we aimed to evaluate the donation-attributable risk of inguinal hernia repair. Objective: To evaluate long-term rates of inguinal hernia repair in male living kidney donors compared to nondonors. Design and Setting: Population-based, retrospective matched cohort study using linked health administrative databases from Ontario, Canada. Patients: 848 male living kidney donors aged ≥18 years who underwent laparoscopic donor nephrectomy between April 1, 2002, and March 31, 2023, were matched (1:10) to 8480 healthy male nondonors based on age, cohort entry date, rurality, neighbourhood income, and prior vasectomy. Individuals with prior scrotal conditions or previous inguinal hernia repair were excluded. Measurements: The primary outcome was inguinal hernia repair. Methods: Risk was assessed using Cox proportional hazards models with robust variance. Cumulative incidence was estimated at key time points using Aalen-Johansen methods, treating death as a competing event. To contextualize the findings, incidence rates were also examined after other renal (e.g., nondonor nephrectomy, pyeloplasty) and abdominal surgeries. Results: Over a median follow-up of 8.8 years, 4.7% of donors (40 of 848) and 3.4% of nondonors (287 of 8480) underwent inguinal hernia repair. Donors had a modestly higher risk of undergoing inguinal hernia repair than nondonors (4.9 vs. 3.5 events per 1000 person-years; hazard ratio (HR) 1.40; 95% CI, 1.01-1.93; Limitations: This study relied on administrative data, which lacked information on hernia type (direct or indirect), laterality, pre-existing asymptomatic hernias, and key confounders such as body mass index and occupation. Donors may differ from nondonors in care-seeking behaviours and lifestyle factors, which could influence the observed risk. Conclusions: In contrast to the markedly higher risk of hydrocele repair, the donation-attributable risk of inguinal hernia repair in the years following laparoscopic donor nephrectomy appears modest, and in some comparisons was not evident. These findings support current counselling and selection practices for prospective donors, for which this outcome does not warrant specific consideration.