Relationship of donor kidney volume and vascular anatomical features with graft function in living donor kidney transplantation

Aims: To assess associations of donor kidney volume and vascular anatomy with Doppler findings, 12-month graft function, and acute rejection after living-donor kidney transplantation.Methods: This retrospective single-center study included 90 transplant pairs. Donor computed tomography assessed kidney volume and vascular anatomy. Recipient Resistive Index (RI), Pulsatility Index (PI), creatinine, and laboratory-reported estimated glomerular filtration rate (eGFR) were recorded on day 1 and through month 12. Kidney volume was indexed to body surface area (BSA) and weight. False-discovery-rate correction and complete-case linear models were used.Results: Median kidney volume was 105.5 ml [interquartile range (IQR), 90.0-126.3], and 7 recipients (7.8%) had biopsy-proven rejection. Day-1 PI was nominally higher with rejection (1.62 [IQR, 1.49-2.25] vs. 1.32 [IQR, 1.01-1.60]; p=0.026), but not after false-discovery-rate correction (q=0.131). At month 12, kidney volume (rho=0.266; q=0.017), volume/BSA (rho=0.298; q=0.010), and volume/weight (rho=0.292; q=0.010) correlated positively with eGFR. Volume/BSA remained associated with eGFR in demographic (beta=4.36; 95% confidence interval, 0.11-8.62; p=0.045) and perioperative models (beta=4.36; 95% confidence interval, 1.35-7.36; p=0.005). Vascular comparisons were not significant.Conclusion: Recipient-size-normalized kidney volume showed modest associations with 12-month graft function. The PI-rejection association did not survive correction, and negative vascular comparisons do not establish equivalence.