Renal Artery Diameter Is a Surrogate Marker for Kidney Volume in Living Kidney Donors

Donor kidney volume (KV) is an increasingly important parameter evaluated before living kidney donation; however, KV measurements on computed tomographic (CT) scanning requires a manually intensive process of manual or semiautomatic segmentation of kidneys with interobserver variation. Renal artery diameter (RAD) is an easier marker to measure, and this study aims to investigate the relationship between donor RAD and KV.

A retrospective review of 77 patients who underwent living donor nephrectomy was conducted. Bilateral KVs were measured based on contrast-enhanced CT scan imaging, and renal artery maximum diameter was measured by direct visualization on the arterial phase of transverse CT sections.

On regression analysis, there was a significant association between the right and left RADs and their ipsilateral KVs with a regression coefficient of 7.9 (95% CI, 1.3-14.5; P = .02) and 9.8 (95% CI, 3.3-16.3; P = .004), respectively. Mean total RAD correlated with total KV with a regression coefficient of 9.3 (95% CI, 3.8-14.7; P = .001) and weakly correlated with estimated glomerular filtration rate with a Pearson coefficient of .10.

This study demonstrates that renal artery size is positively associated with KV and may be used as an easily measured surrogate marker for kidney size with its attended implications in living donor transplantation.