The objective of the study is to evaluate the clinical value of ureteroscopic holmium laser lithotripsy for the treatment of nephrolithiasis. Clinical data of 44 patients treated for renal stones with polyscope modular flexible ureter- oscopic holmium laser lithotripsy from May 2014 to April 2015 were retrospectively analysed. Following the operation, F4.7 D-J stents were routinely indwelled for 4 weeks and catheterization for 1-3 days. A plain kidney, ureter, and blad- der (KUB) X-ray was performed on postoperative days too. A total of four success cases were determined following the first treatment. The remaining 40 cases were first placed with double-J stent and the surgery was performed one week later. Stone sizes between 0.8-4.0 cm in diameter were defined. The operation time for the treatment was 80-180 minutes. Patients were discharged within 3-5 days, and the double-J stent was removed within 1-3 months. 39 patients were found to be completely stone-free at approximately three months postoperatively. However, five patients were shown to have 11.1% of residual stones after treatment. No blood transfusion, septic shock, ureteral injury, or other complications were reported. Flexible ureteroscopic holmium laser lithotripsy is safe and effective for the treatment of nephrolithiasis. This approach could be a valuable choice for the treatment of patients with renal stones.
PD21-07 PROSPECTIVE RANDOMIZED STUDY OF FLEXIBLE URETEROSCOPIC HOLMIUM LASER LITHOTRIPSY USING HIGH-FREQUENCY STONE DUSTING VERSUS A LOW-FREQUENCY STONE BREAKING PROTOCOL FOR THE TREATMENT OF RENAL STONES LARGER THAN 2 CM