Clinical assessment of renal function stabilization after living donor nephrectomy

Abstract

BACKGROUND: Few studies have evaluated the long-term effects of kidney donation on the donors themselves. This study investigated postoperative renal function stabilization in kidney donors after living-donor transplantation to determine the optimal follow-up period.

METHODS: Between March 2006 and July 2010, 203 patients in our hospital underwent live donor nephrectomy. Renal function recovery patterns were analyzed by calculating the postoperative rate of change of their Modification of Diet in Renal Disease study equation estimating glomerular filtration rate (MDRD-GFR) versus their preoperative level (%MDRD). We divided normal (n = 121) versus chronic kidney disease subjects (CKD; MDRD-GFR < 60 mL/min/1.73 m(2) at 6 months postoperatively, n = 82) for 1 year follow-up to compare time to renal function stabilization using the repeated measured data method.

RESULTS: When all donors were considered together at 1 month after transplantation, MDRD-GFRs were significantly increased compared with earlier follow-up times (for postoperative days 1, 4, and 7), P values were < .001, .006, and .002, respectively). Among all donors, there was no significant difference between MDRD-GFRs at 1 versus 3, 6, and 12 months posttransplantation (P < .05 in all three comparisons), indicating renal function stabilization. Importantly the %MDRD was significantly higher among the normal than the CKD group at postoperative months 1, 3, and 6 (P < .05 for all comparisons), although after 12 months there was no significant difference between the groups (69.06 ± 9.28% versus 70.14 ± 8.38%, P = .442).

CONCLUSION: After live donor kidney transplantation, renal function began to stabilize at 1 month postoperatively. Poor renal functional recovery and CKD later were predicted by inferior stabilization at 1 month postnephrectomy. These data suggested that even patients with normal GFRs should be followed beyond 1 year postoperatively to determine their ultimate renal functional outcomes.