Evaluation of factors predicting recoverability of renal function after pyeloplasty in adults.

ABSTRACT

AIM: To analyze the status of renal function after pyeloplasty in a large contemporary adult series and to detect which variables predict improvement of renal function. MATERIALS AND METHODS: 85 adult patients were retrospectively identified who had undergone pyeloplasty between January 2002 and May 2011 with available pre- and postoperative diuretic scintigraphy. Preoperative differential renal function (DRF) and single-kidney GFR (SKGFR) were obtained by (99m)Tc-MAG-3 diuretic scintigraphy. Baseline-weighted (bw-) DRF and SKGFR were calculated between baseline conditions and time of last follow-up. Factors that explain the variance of bw-DRF and bw-SKGFR were determined. RESULTS: The mean (SD) preoperative DRF significantly increased from 34% (11.6) to 37.2% (11.8) after pyeloplasty (p < 0.001). Similarly, mean (SD) SKGFR showed a significant improvement from 31.2 (12.9) to 35.9 (15) ml/min (p < 0.001). Patients with a lower baseline DRF (≤40%) showed a significant improvement as opposed to those with a higher baseline DRF (>40%) (p < 0.001 and 0.3, respectively). Baseline DRF and cortical thickness explained the variance in bw-DRF and bw-SKGFR with more contribution of baseline DRF. CONCLUSIONS: Renal function showed improvement after pyeloplasty in adults and preoperative DRF and cortical thickness were the predicting variables.