ObjectiveTo evaluate the safety and efficacy of flexible ureteroscopic lithotripsy for renal stones of longer than 2 cm in diameter. MethodsFrom August 2012 to July 2014, 15 selected patients with renal calculi of longer than 2 cm in diameter underwent flexible ureteroscopic lithotripsy with holmium laser by the same surgeon. Preoperative indwelling ureteral stent was performed for 1-2 weeks, and super smooth guidewire was inserted after checking and dilation of the ureter was performed with F8.0/9.8 rigid ureterosope. Flexible ureteroscope sheath was inserted through guidewire. Ureterosope was followed by flexible ureteroscope sheath. Larger stone fragments were removed by basket. ResultsThe success rate of ureteroscopic insertion was 100% and no severe intraoperative complications occurred. The operation time ranged from 50 to 125 minutes averaging 75. No ureteral perforations or pyonephrosis or acute renal insufficiency occurred. Four patients had high fever after operation and improved after positive anti-infection treatment. After 2 days, the stone-free rate was 73.3% (11/15) by reviewing KUB. The follow-up of 4 weeks showed the stone-free rate was 86.7% (13/15). One case of stone fragments retained in the middle and lower ureter and the fragments were taken out by ureteroscopic lithotripsy. The other case of renal residual calculi was operated by flexible ureteroscope holmium laser lithotripsy in two stage. ConclusionFlexible ureteroscopic lithotripsy is a favorable option for patients with renal stones of longer than 2 cm in diameter, especially for recurrent renal calculi.