For upper ureteral stone, semirigid ureteroscopy or flexible ureteroscopy? Strengths and weaknesses

Background Flexible and semirigid ureteroscopy are two often used modalities in treating for upper ureteral stone. How about the outcome of each procedure? Methods A retrospective cohort study among 167 patients who underwent flexible or semirigid ureteroscopic lithotripsy was performed. The pre-, intra-, postoperative and one-year follow-up outcomes were taken into comparison. Results Significantly higher instant stone-clearance rate (81.3% vs. 92.4%, p = .032) and less operative time (62.1 +/- 27.6 min vs. 44.1 +/- 24.6 min, p<.001) were found in semirigid ureteroscopy. However, the stone-clearance rate at one month (90.7% vs. 93.5%, p = .500) was similar. Baseline characteristics including patient demographics, stone characteristics, duration of stone symptoms, hospital stay, expense, and complications between groups were approximately same. Three cases of stricture were found in the flexible ureteroscopy, and two in the semirigid ureteroscopy. Outcomes showed no significant difference. Further analysis showed that flexible ureteroscopy was likely more negatively affected by hydronephrosis and stone size, and semirigid ureteroscopy was more affected by stone location. Conclusion flexible ureteroscopy and semirigid ureteroscopy both had high stone clearance rate in the treatment for upper ureteral stones. They had similar outcomes and follow-up results. However, they also had their each most suitable application object.