Endourology & Stone Disease(비디오) (V-004) The Feasibility of Pop-Dusting Using High Power Laser (2J x 50Hz) in Retrograde Intrarenal Surgery for Renal Stones 성균관의대 삼성서울병원, 비뇨의학과 교실 정재훈, 백민기, 박상수, 한덕현 Objective: Recently, retrograde intrarenal surgery (RIRS) using laser lithotripsy has become popular. However, the optimal laser energy setting for pop-dusting has not been established. In this study, we report our experiences of RIRS using the high power (up to 100 W) pop-dusting (HPPD) technique. Methods: This study retrospectively assessed 82 cases with RIRS using HPPD. Patients who underwent abdominal computed tomography (CT) or MAG3 diuretic renal scan at 3 months postoperatively were included in this study. Patient and stone characteristics and peri- and post-operative outcomes were evaluated. Results: The average number of renal stones was 3.67 ± 4.11, and the average length of the largest stones was 13.30 ± 6.41 mm. The mean Hounsfield units was 959.99 ± 384.73. The operation time was 58.10 ± 26.67 minutes. The mean HPPD time was 11.93 ± 9.48 minutes with settings of 1.97 ± 0.25J and 48.78 ± 3.29Hz. The stone-free rate was 89%. The mean hospital stay was 1.68 ± 1.29 days. Pelvocalyceal and ureter injuries were observed in 9.8% and 32.9% of the study population, respectively. However, there was no transfusion, subcapsular hematoma, persistent urinary leakage, ureteral or infundibular stricture, or renal functional deterioration. There was transient postoperative fever in 12.2% of the study population. Conclusions: HPPD could be performed safely during RIRS for renal stones without significant complications such as collecting system injury or bleeding. High power laser mode (up to 100W) can be a safe and effective choice for pop-dusting during RIRS, especially for large and hard stones. keywords : Lasers, kidney, calculi