Outcomes of Kidney Donors over 60 Years Old: A Single-Center Cohort Study

Impact of Age 70 years or Older on Donors for Living-Donor Kidney Transplantation

Introduction

Kidney transplantation (KT) involving elderly living kidney donors (LKDs) is becoming more frequent because of a profound organ shortage. The efficacy of KT involving grafts obtained from LKDs aged 70 years or older has been reported. However, the safety of donor nephrectomy in LKDs aged 70 years or older, including that associated with changes in the estimated glomerular filtration rate (eGFR), has not been investigated. This study investigated the outcomes of LKDs aged 70 years or older after donor nephrectomy.

Methods

This single-center, retrospective cohort study included 1226 LKDs who underwent donor nephrectomy between January 2008 and December 2020. LKDs were stratified into the following age groups: 30 to 49 years (244 LKDs), 50 to 69 years (803 LKDs), and 70 to 89 years (179 LKDs). Surgical outcomes, postoperative eGFR changes, end-stage renal disease (ESRD) rates, and mortality rates were compared among these groups.

Results

No significant difference in surgical outcomes was identified among the groups. LKDs aged 70 to 89 years experienced the lowest eGFR changes at all time points and the lowest eGFR improvement; however, ESRD was not identified in any group during the observation period. Mortality was the highest among LKDs aged 70 to 89 years compared to the other age groups.

Conclusion

Surgical outcomes, eGFR changes, and ESRD incidences can support the safety of donor nephrectomy in LKDs aged 70 years or older. Considering the advanced age, the high mortality rates in LKDs aged 70 years or older could be considered acceptable.

Risks for donors associated with living kidney donation: meta-analysis

BACKGROUND

Living kidney donation risk is likely to differ according to donor's demographics. We aimed to analyse the effects of age, sex, body mass index (BMI) and ethnicity.

METHODS

A systematic review and meta-analysis was undertaken of the effects of preoperative patient characteristics on donor kidney function outcomes, surgical complications, and hypertension.

RESULTS

5129 studies were identified, of which 31 met the inclusion criteria, mainly from the USA and Europe. The estimated glomerular filtration rate (eGFR) in donors aged over 60 years was a mean of 9.54 ml per min per 1.73 m2 lower than that of younger donors (P < 0.001). Female donors had higher relative short- and long-term survival. BMI of over 30 kg/m2 was found to significantly lower the donor's eGFR 1 year after donation: the eGFR of obese donors was lower than that of non-obese patients by a mean of -2.70 (95 per cent c.i. -3.24 to -2.15) ml per min per 1.73 m2 (P < 0.001). Obesity was also associated with higher blood pressure both before and 1 year after donation, and a higher level of proteinuria, but had no impact on operative complications. In the long term, African donors were more likely to develop end-stage renal disease than Caucasians.

CONCLUSION

Obesity and male sex were associated with inferior outcomes. Older donors (aged over 60 years) have a larger eGFR decline than younger donors, and African donors have a higher incidence of ESRD than Caucasians.

High BMI and male sex as risk factor for increased short-term renal impairment in living kidney donors - Retrospective analysis of 289 consecutive cases

BACKGROUND

Kidney transplantation represents the treatment of choice for end-stage renal disease (ESRD). However, nephrectomy bears certain short- as well as long-term risks for the healthy, voluntary donor. As obesity is increasing and is a known risk factor for surgical complications, we wanted to assess the impact of BMI on perioperative complication rates and renal function.

MATERIALS AND METHODS

We retrospectively assessed patients undergoing living donor kidney nephrectomy at our institution. We identified 289 donors that underwent unilateral nephrectomy between January 2006 and December 2015. Donors were categorized according to their BMI (BMI <25 kg/m², BMI ≥25/<30 kg/m², BMI ≥30 kg/m²). Where indicated, analysis of variance (ANOVA) was used to compare groups, a stepwise linear regression model was used to assess impact of BMI on the change of eGFR.

RESULTS

126 donors (43.6%) had a BMI <25 while 120 (41.5%) had a BMI ≥25/<30 and 43 (14.9%) were obese with a BMI ≥30. BMI had no statistically significant influence on the percentage of laparoscopic approach (86.5% vs. 83.3% vs. 88.4%, p = 0.6564), on conversion rates (0% vs. 2.0% vs. 2.6%, p = 0.2879) or postoperative complication rates defined as Clavien Dindo ≥ II (8.7% vs. 13.3% vs. 14.0%, respectively; p = 0.4474). Notably, there were no Grade III or higher complications in any group. There was no difference in pre-operative kidney function, postoperative surgical site infection or systemic infection. BMI and male sex had a statistically significant influence on short-term decline of eGFR.

CONCLUSION

Obese donors do not suffer from an increased risk of intraoperative or perioperative complication rates. However, male sex and high BMI are associated with a more pronounced short-term decline in renal function. The impact of BMI on long-term consequences for kidney donors needs to be defined in larger prospective cohorts.