Use of Preoperative Renal Volumetry to Predict Postdonation Renal Function With Inulin Clearance as Indicator in Japan.

PURPOSE: The aim of this study was to investigate the utility of preoperative CT-based renal volume assessment to predict postoperative renal function in living kidney donors. Specifically, favorable renal function was defined as chronic kidney disease (CKD) stage 1 or 2 at 1 year after donation, determined by the glomerular filtration rate (GFR) measured based on inulin clearance (Cin).

METHODS

This study included 40 donors who underwent kidney donation at our institution between June 2012 and May 2021. GFR was measured using Cin, and CKD stages were assigned accordingly. Predictive factors for favorable renal function (CKD stage 1 or 2) at 1 year postdonation were analyzed using logistic regression.

RESULTS

The median donor age was 63 years (range: 37-75), and 35.0% were male. Median pre- and postoperative Cin values were 84.9 (range: 59.0-133.4) and 56.7 (range: 34.7-95.0) mL/min, respectively. Multivariate logistic regression revealed age ≤ 55 and residual kidney volume-to-weight ratio (RKV/W) ≥ 2.78 as independent factors predicting favorable renal function. A scoring system based on these factors (0 points for none, 1 point for 1 factor, 2 points for both) demonstrated significantly better postoperative renal function in donors with 1 or more points compared with those with 0 points (median Cin: 63.3 vs 53.7 mL/min, respectively, P = .00074).

CONCLUSIONS

Age and RKV/W are factors predicting favorable renal function after kidney donation. A predictive scoring system based on these factors could assist in assessing donor eligibility and guiding clinical decision-making.