Effect of multiple access tracts during percutaneous nephrolithotomy on renal function: evaluation of risk factors for renal function deterioration.

Purpose: To assess the impact of multiple access tracts during percutaneous nephrolithotomy (PCNL) on short-and midterm renal function, and to determine risk factors predicting renal function deterioration and/or recoverability. Patients and Methods: Patients undergoing PCNL with multiple punctures were prospectively enrolled. Preoperative evaluation included dimercaptosuccinic acid and diethylenetriaminepentaacetic acid renography. Patients were classified according to baseline renal function into patients with normal (<1.4 mg/dL) serum creatinine (group A) and patients with elevated (>= 1.4 mg/dL) serum creatinine (group B). Patients were followed with serial serum creatinine evaluations and a repeated renography at 12 months. Factors evaluated for possible impact on renal function changes included preoperative renal function, number of access tracts, hypertension, and diabetes mellitus. Results: There were 102 patients 21 to 65 (mean 39.9) years who completed the study. Fifty patients (group A) had normal preoperative serum creatinine levels and glomerular filtration rate (GFR), which showed no statistically significant change 12 months after PCNL. Fifty-two patients had baseline renal impairment (group B), and they experienced statistically significant worsening of the serum creatinine level and GFR at 12 months postoperatively (P < 0.001). Ten (19.23%) patients in group B had a significant deterioration of GFR more than 25%. Independent risk factors for this poor outcome were elevated (>= 1.4 mg/dL) preoperative serum creatinine level, diabetes, and hypertension. Conclusion: PCNL with multiple tracts carries a risk of adversely affecting renal function. Preoperative baseline renal impairment, diabetes, and hypertension are risk factors for significant renal function deterioration after the procedure.