Early changes in volume and function of the remaining kidney after unilateral donor nephrectomy

The early changes that occur in the volume and function of the remaining kidney, after uni-nephrectomy for organ donation, were studied in 25 living donors. Serum creatinine (S Cr), creatinine clearance (Cr Cl), renographic clearance tests for total and split renal functions as well as renal volume using ultrasound were determined before and three months after donation. In 76% of the donors, Se Cr showed an increase after kidney donation, but all values were within normal range. The total kidney function in terms of Cr Cl, showed a drop of 36% from the pre-donation value. After three months post donation, the clearance of the remaining kidney increased by 5% to 64% (mean 34%) of the pre-donation values, measured by Tc 99m DTPA renography. Compensatory hypertrophy of the remaining kidney also occurred as evidenced by the ultrasound evaluation which showed an increase in the renal volume by 15%. Our study shows that compensatory changes occur early i.e., within the first three months after uni-nephrectomy. However, prolonged follow-up of these donors is necessary to assess the long­term structural and functional changes in the remaining kidney.