Predicting Residual Renal Function and Long-Term Renal Function Recovery in Living Kidney Donors Using Pre-Donation Computed Tomography Volumetry.

BACKGROUND

Living kidney donors recover their renal function after a decreased glomerular filtration rate initially. We evaluated the relationship between residual renal function predicted from split renal function measured using computed tomography (CT) volumetry and the actual compensation of renal function after donation.

METHODS

We retrospectively reviewed living kidney donors between June 2011 and October 2021. The kidney function at predonation and at 3 months, 1 year, and 3 years postdonation was also reviewed. Predicted residual renal function was calculated using the predonation estimated glomerular filtration rate and CT volumetry. The renal functional recovery rate was calculated using predicted residual renal function and postdonation estimated glomerular filtration rate.

RESULTS

We retrospectively assessed 57 living kidney donors, including 29 and 28 donors aged < 65 and ≥ 65 years, respectively. Although the ≥ 65-year-old donors had significantly lower postdonation estimated glomerular filtration rate and renal functional recovery rate than those aged < 65 years at 3 months and 1 year, the difference was not significantly different at 3 years. Furthermore, longitudinal postdonation changes in the estimated glomerular filtration rate and renal functional recovery rate were significantly different between the two groups.

CONCLUSIONS

Predonation renal volume decreases with age in living kidney donors. Although age is strongly correlated with postdonation estimated glomerular filtration rate, long-term renal functional recovery was identified in older donors. Therefore, the predicted renal functional reserve should be assessed in older donors.