Abstract: Objective To investigate the clinical effect of ureteroscopic lithotripsy using Swiss Lithoclast （URSL） on middle and lower ureteral calculi complicated with infection. Methods Sixty middle and lower ureteral calculi patients with infection treated from January 2017 to July 2020 were selected and divided into a control group （n=30） and a study group （n=30） by random stratification method. The control group was treated with extracorporeal shock wave lithotripsy （ESWL）; the study group was treated with URSL. Surgical effects were probed. Results The one-time removal rate in the study group （90%） was higher than that in the control group （76.67%）. The complication rate in the study group （6.67%） was lower than that in the control group （26.67%, P<0.05）. Before surgery, the levels of procalcitonin, leukocyte （LEU）, hypersensitive C-reactive protein （hs-CRP）, creatinine, and white blood cell count between the two groups were not significantly different （P>0.05）： After surgery, the five indicators in the study group were significantly lower than those in the control group （P<0.05）. Conclusion URSL has better effects than ESWL for middle and lower ureteral calculi patients.

Key words: Middle and lower ureteral calculi, Infection, Ureteroscopic lithotripsy using Swiss Lithoclast, Extracorporeal shock wave lithotripsy, Surgical effect