Predictors of Kidney Volume Change and Delayed Kidney Function Recovery After Donor Nephrectomy

PurposeTo our knowledge the effects of preoperative kidney volume in living donors on the post-donation change in size and function of the remaining kidney have not been investigated. We studied the association between preoperative kidney volume, and volume change and delayed kidney function recovery in donors.Materials and MethodsFrom 2007 to 2008 we investigated 222 living donors. Kidney volume before and 6 months after surgery was estimated using the voxel count method. We analyzed correlations of kidney volume with patient characteristics, kidney function and actual kidney weight. To identify predictors of the volume increase of the remaining kidney and predictors of delayed kidney function recovery we performed regression analysis.ResultsMean ± SD total kidney volume was 311.9 ± 50.6 cc and it correlated with weight, body surface area and kidney function (p <0.001). The mean volume increase in the remaining kidney was 27.6% ± 9.7% (range 4.5% to 66.1%). Younger age (p <0.001) and lower preoperative volume of the remaining kidney (p = 0.019) were significant predictors of a greater increase in kidney volume on multiple linear regression analysis. Older age (OR 1.07, p <0.001), higher body mass index (OR 1.20, p = 0.008), lower preoperative kidney volume of the remaining kidney (OR 0.98, p = 0.003) and a lower preoperative diethylenetetramine pentaacetic acid glomerular filtration rate in the remaining kidney (OR 0.95, p = 0.017) were significant predictors of delayed kidney function recovery on multiple regression analysis.ConclusionsKidney volume measured by the voxel count method was accurate and correlated with kidney function. Preoperative kidney volume is an independent predictor of the volume increase and delayed kidney function recovery in donors that could be used clinically.