Efficacy of percutaneous nephrostomy during flexible ureteroscopy for renal stone management

Purpose: Preoperative percutaneous nephrostomy (PCN) can be applied to urinary stone patients with pyelonephritis as well as obstructive uropathy; thus, some patients undergo flexible ureteroscopy (fURS) in the presence of a PCN tube. We evaluated the effectiveness of PCN during fURS for the management of renal stones. Materials and Methods: We retrospectively analyzed 130 consecutive patients who un-derwent fURS for renal stones between January 2009 and December 2011. All fURS procedures were performed by a single experienced surgeon. The patients were divided into two groups depending on the presence of PCN during the surgery: patients with PCN (group 1, n=41) and patients without PCN (group 2, n=89). To evaluate operative outcomes, we compared success rates, operative times, and complication rates. We de-fined success as the absence of any residual stones in the kidney or stone fragments less than 2 mm that were too small to be extracted during follow-up. Results: There were no significant differences in age, sex, body mass index, stone later-ality, burden, or location between the two groups. The mean operative times of groups 1 and 2 were 50.1 and 58.3 minutes, respectively (p=0.102). The success rates of groups 1 and 2 were 95.1% and 82.0%, respectively (p=0.044). There was no statistically sig-nificant difference in the complication rate between groups 1 and 2 (p=0.888). Conclusions: Flexible ureteroscopy in the presence of PCN produced a superior outcome in terms of the success rate without increasing the operative time or complication rate. PCN may be helpful to induce better outcomes of fURS.