According to new research, male living kidney donors who underwent laparoscopic nephrectomy were at a substantially elevated long-term risk of requiring scrotal surgery. A population-based cohort study in Annals of Internal Medicine estimated 14% of male donors underwent scrotal surgery within 20 years compared with 0.7% of matched nondonors—about 39 times the likelihood vs controls.
Led by Amit X. Garg, MD, PhD, of independent nonprofit research institute ICES in Ontario, Canada, the researchers tracked 898 male donors in Ontario who underwent laparoscopic nephrectomy between 2002 and 2023, with follow-up through March 31, 2024, and matched each to 10 male nondonors on age, income, residence, and surgical history. Laparoscopic nephrectomies were performed at 6 academic hospitals by 35 transplant surgeons, and about 90% were left-sided. Most scrotal surgeries (more than 90%) were hydrocelectomies performed under general anesthesia by different surgeons at different hospitals than the original nephrectomies. Over a median 9.1-year follow-up (8.4 years in donors), 70 donors (7.8%) required hospitalization for scrotal surgery vs 19 nondonors (0.2%). This rate translated to 8 vs 0.2 events per 1,000 person-years.
Cumulative incidence in donors reached 0.3% at 1 year, and rose to 4% at 5 years, 8% at 10 years, 12% at 15 years, and 14% at 20 years. In nondonors, the corresponding values were 0%, 0.1%, 0.2%, 0.4%, and 0.7%. By laterality among laparoscopic donors, rates did not differ significantly (around 8 vs 11) for left vs right procedures, and the median time from donation to scrotal surgery was approximately 5 years. Among the 70 donors who underwent scrotal surgery, 34 (49%) had one follow-up outpatient visit with the operating surgeon and 26 (37%) had 2 or more visits. Fewer than 6 (less than 9%) returned to the operating room for scrotal surgery in the following year.
The team also examined 268 male donors who had open nephrectomies over the same period. The weighted incidence rate of scrotal surgery was higher following laparoscopic than open nephrectomy (approximately 8.3 vs 1.5 events per 1,000 person-years). In a post hoc comparison, open-nephrectomy donors also had higher rates than matched nondonors (about 1.8 vs 0.2). Secondary outcomes showed similarly elevated utilization: scrotal ultrasounds were performed in 192 donors (21%) and 589 nondonors (7%) at rates of about 26 vs 7 per 1,000 person-years. Approximately 78% of donor ultrasounds were ordered by primary care physicians.
In exploratory analyses of male nondonors who underwent various laparoscopic renal surgeries, long-term scrotal surgery rates ranged from 1 to 3 per 1,000 person-years—4 to 10 times higher than rates in males in the general population (around 0.3). In contrast, rates ranged from 0.0 to 0.5 among nondonors who had nonrenal surgeries (e.g., adrenalectomy, splenectomy).
Mechanisms underlying ipsilateral hydrocele development remain uncertain. Proposed contributors include disruption of lymphatic drainage and potential nerve injury to the spermatic cord/plexus. The researchers also noted that energy devices used in laparoscopy may cause greater damage than open techniques. In addition to future research to understand this mechanism, Dr. Garg and colleagues suggested actions that can be taken to safeguard living kidney donation because it remains a benefit to donors, recipients, families, and society at large, they wrote.
Specifically, their suggestions included informing male donors about the risks and symptoms to monitor for after donation, as well as donor access to necessary medical care for donation-related complications, for which they "should not incur a financial burden. Including a scrotal ultrasound in the predonation evaluation would allow for documentation of baseline findings and aid in assessing donors who develop new symptoms following laparoscopic nephrectomy." They added that "analyzing intraoperative video recordings may provide insights into the aspects of donor nephrectomy that affect hydrocele formation."
The study achieved the highest Newcastle-Ottawa Scale rating, with less than 4% loss to follow-up. Participants were followed until death, emigration, or March 31, 2024, using linked health care databases at ICES. Limitations included potential underestimation if patients did not seek care. Databases lacked surgical-technique details, scrotal symptom data, laterality of scrotal surgery, and information on symptom resolution, and no codes indicate the side of scrotal surgery.
Disclosures can be found in the published study.
Source: Annals of Internal Medicine
