Mortality Risk Dropped for Living Kidney Donors Over the Past Decade

The risk of perioperative mortality for living kidney donors has dropped in the past decade, 30-year national registry data indicated.

From 2013 to 2022, only five living kidney donors died within 90 days post-donation, for a rate of 0.9 (95% CI 0.3-2.0) per 10,000 donations, reported Dorry Segev, MD, PhD, of the NYU Langone Transplant Institute in New York City, and colleagues in a JAMA research letter.

This was a significant decline from the two decades prior:

• 2003-2012: 18 deaths; 2.9 (95% CI 1.7-4.6) per 10,000
• 1993-2002: 13 deaths; 3.0 (95% CI 1.6-5.1) per 10,000

Of the deaths captured in this study, half occurred within the first 7 days after donation.

“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,” said co-author Allan Massie, PhD, of NYU Langone Health, in a statement.

Segev added that 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.”

The current guideline, the 2017 Kidney Disease: Improving Global Outcomes (KDIGO) for living kidney donors, was based on data from 1994 to 2009, which calculated the living donor mortality rate at 3.1 per 10,000 donations.

“Open donor nephrectomy, standard of care in the 1990s, has now been replaced almost completely by laparoscopic nephrectomy,” Segev’s group pointed out. “Because of this transition, as well as improvements in donor selection, perioperative care, and surgical technique, prior estimates of perioperative mortality may not accurately represent current risk to donors.”

In order to calculate updated mortality rates, Segev’s group assessed 164,593 living donors in the Scientific Registry of Transplant Recipients. Deaths were captured from the Organ Procurement and Transplantation Network living donor follow-up reported by transplant programs, among other sources. According to the network’s policy, all donor deaths within 2 years of donation must be reported within 72 hours of the hospital’s becoming aware of the death.

The most common cause of death was hemorrhage: eight of 19 deaths with a reported cause. Two were due to infection, another two were due to pulmonary embolism, and two were attributed to cardiovascular causes. One death was caused by a cerebrovascular accident, and another was listed as a homicide.

When broken down by donor characteristics, male donors were significantly more likely to die within 90 days of donation than female donors (4.0 vs 1.0 per 10,000 donations). Though not statistically significant, there was a numerically higher rate of mortality for Black donors (4.2 per 10,000) versus white donors (2.0 per 10,000) or multiracial donors/donors of other races (1.3 per 10,000).

Mortality was consistent across BMI categories, but was significantly higher for donors with a history of pre-donation hypertension (7.5 vs 1.4 per 10,000, P=0.03).

As for procedure type, mortality was more common among donors who had open versus laparoscopic nephrectomy, though this wasn’t significant (4.3 vs 1.9 per 10,000, P=0.08).

Since only 36 perioperative deaths occurred over the 30-year study span, the researchers pointed out that there was limited power to estimate relative risks.