Perioperative Mortality Risk After Living Kidney Donation Significantly Declined in 2013-2022

Allan Massie, PhD

Credit: NYU Langone Health

New research is providing clinicians with an updated estimate of perioperative mortality risk in living kidney donors, with results suggesting a substantial decline in recent decades to less than 1 death per 10,000 donations.¹

The study was published in JAMA and leveraged data from the Scientific Registry of Transplant Recipients from 1993-2022 to highlight a significant decrease in perioperative mortality after living kidney donation in 2013-2022 compared with 1993-2002 and 2003-2012. Of note, greater risk was observed among male donors and donors with a history of hypertension.¹

“While we had always understood that kidney donation is safe, our findings suggest that mortality among donors is extremely rare, and the procedure is safer than ever before,” lead investigator Allan Massie, PhD, director of the Center for Surgical and Transplant Applied Research Quantitative Core at NYU Grossman School of Medicine, said in a press release.²

According to the Organ Procurement and Transplantation Network (OPTN), as of March 2024, nearly 90,000 patients were on the kidney transplant waitlist.³ Data from the United Network for Organ Sharing show more than 6,900 living donor transplants were done in 2023, with most living donors providing a kidney for transplant.⁴ Current Kidney Disease: Improving Global Outcomes (KDIGO) guidelines on living kidney donation cite 1 in 3000 (0.03%) 90-day all-cause mortality findings from a US study of 80,347 donors between 1994-2009 and thus suggest a low risk of perioperative mortality for living donors, but the accuracy of this figure in 2024 is unclear.⁵

To characterize temporal trends in perioperative mortality in donors and risk factors associated with this event, investigators conducted a national registry study using data from the Scientific Registry of Transplant Recipients on living kidney donors from 1993-2022. They calculated mortality ratios within 90 days of donation stratified across 3 time periods: 1993-2002, 2003-2012, and 2013-2022.¹

Death events were captured from OPTN living donor follow-up reported by transplant programs; National Technical Information Service Limited Access Death Master File; and deaths made available to the OPTN contractor through an interagency data sharing agreement between the Centers for Medicare and Medicaid Services and the Health Resources and Services Administration, and secondarily verified by the OPTN contractor.¹

Of 164,593 donors in the present study, 36 died within 90 days of donation (2.2 per 10,000 cases). Investigators noted 50% of deaths occurred within the first 7 days, and when cause-of-death data were available, the most common cause was hemorrhage (42%).¹

While mortality was comparable in 1993-2002 (13 deaths; 3.0 per 10,000; 95% CI, 1.6-5.1) and 2003-2012 (18 deaths; 2.9 per 10,000; 95% CI, 1.7-4.6), it declined statistically significantly in 2013-2022 (5 deaths; 0.9 per 10,000; 95% CI, 0.3-2.0; P = .01). Investigators pointed out there were no statistically significant differences across subgroups of age, race, and ethnicity.¹

Compared with White donors (2.0 per 10,000), mortality was higher for Black donors (4.2 per 10,000) and lower among donors who were neither Black nor White (1.3 per 10,000; P = .12). Additionally, male donors were at higher risk than female donors (4.0 vs 1.0 per 10,000; P = .25).¹

Mortality was greater for donors who had open versus laparoscopic procedures, although not statistically significant (4.3 vs 1.9 per 10,000; P = .08). Although mortality was consistent across categories of BMI, it was greater among donors with a history of pre-donation hypertension (7.5 vs 1.4 per 10,000; P = .03).¹

Investigators acknowledged multiple limitations to these findings, including the small number of perioperative deaths during the study period and the subsequent limited power to estimate relative risks as well as the potentially incomplete follow-up.¹

“These results demonstrate that the current guidelines used to inform potential kidney donors of their risks need to be updated to reflect nearly a decade of safety improvements,” said study senior investigator Dorry Segev, MD, PhD, professor and vice chair in the department of surgery at NYU Grossman School of Medicine.²

References

1. ^{Massie AB, Motter JD, Snyder JJ, et al. Thirty-Year Trends in Perioperative Mortality Risk for Living Kidney Donors. JAMA. doi:10.1001/jama.2024.14527}
2. ^{NYU Langone Health. Kidney Donors’ Risk of Death at All-Time Low. Press Releases. August 28, 2024. Accessed August 29, 2024. https://nyulangone.org/news/kidney-donors-risk-death-all-time-low}
3. ^{Health Resources & Services Administration. Detailed Description of Data. Organ Donation Statistics. March 2024. Accessed August 29, 2024. https://www.organdonor.gov/learn/organ-donation-statistics/detailed-description#fig1}
4. ^{UNOS. Data and Trends. Reports and Dashboards. Accessed August 29, 2024. https://unos.org/data/}
5. ^{Lentine KL, Kasiske BL, Levey AS, et al. KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors. Transplantation. doi:10.1097/TP.0000000000001769}