Purpose To compare the efficacy of RIRS and PNL in lower pole stones ≥2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients’ preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups. Results There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups. Conclusions RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients.

Purpose The aim of the study was to evaluate the efficacy and safety of bilateral single-session retrograde intrarenal surgery in the treatment of bilateral renal stones. Materials and Methods From December 2008 to February 2012, 42 patients who had undergone bilateral single-session retrograde intrarenal surgery (RIRS) and laser lithotripsy were included in the study. The procedures were performed in the lithotomy position on an endoscopy table under general anesthesia, beginning on the side in which the stone size was smaller. Plain abdominal radiography, intravenous urograms (IVU), renal ultrasonography (USG) and / or non-contrast tomography (CT) scans were conducted for all patients. The success rate was defined as patients who were stone-free or only had residual fragment less than 4 mm. Results A total of 42 patients (28 male, 14 female) with a mean age 39.2 ± 14.2 were included in the present study. The mean stone size was 24.09 ± 6.37 mm with a mean operative time of 51.08 ± 15.22 minutes. The stone-free rates (SFR) were 92.8% and 97.6% after the first and second procedures, respectively. The average hospital stay was 1.37 ± 0.72 days. In two patients (4.7%), minor complications (Clavien I or II) were observed, whereas no major complications (Clavien III-V) or blood transfusions were noted in the studied group. Conclusions Bilateral single-session RIRS and laser lithotripsy can be performed safely and effectively with a high success rate and low complication rate in patients with bilateral renal stones.