Abstract:Abstract: Objective To investigate the clinical efficacy of stage I flexible ureteroscopic lithotripsy in treatment of upper urinary calculi without preexistent double J tube. Methods From April 2015 to June 2017, 296 upper urinary stones patients who were treated by flexible ureteroscopic lithotripsy were randomly divided into two groups. The observation group directly surgery without preexistent double J tube, the control group indwelled a double J tube a week before the operation. The clinical data and surgical data of the two groups were statistically analyzed. Results All the patients in this study were successfully treated with flexible ureteroscopic lithotripsy. The success rate of sheath placement was 89.19% in the observation group. The success rate in the control group was 96.62% (P < 0.05). The treatment cost of the two groups was (20 161.02 ± 579.52) yuan and (21 340.16 ± 732.64) yuan in observation group and control group respectively, but there was no significant difference (P < 0.05). The stone-free rates in postoperative one month was 89.87% in the observation group, it was 93.92% in control group, there was no difference between the two groups (P > 0.05). Incidence of complication after operation that caused by double J tube placement in observation group and control group is 28.38% (42/148) and 22.30% (33/148) (P > 0.05). Sepsis, septic shock, renal colic, ureteral calculus, ureteral stenosis and other complications no occurred in the two groups. Conclusion Without placement preexistent ureteral stentin also had higher stone clearance rate before flexible ureteroscopic, and could reduce the discomfort caused by double J tube placement, alleviate pain and economic burden of patients.