Introduction. Retrograde intrarenal surgery (RIRS) increasingly used for upper urinary tract stones removal. According to the he Russian society of urologists guidelines RIRS considered as a first- and second-line option for kidney stones up to 2 cm. The main limitation for its widespread adoption in routine practice are high cost of equipment and consumables. The aim of our study was to evaluate a new reusable fiber-optic ureterorenoscope «SemiFlex Scope».

Materials and methods. This prospective two-center study has been conducted since January 2021. We evaluated the outcomes of single kidney stone removal using a flexible ureterorenoscope «SemiFlex Scope» in 32 patients by two surgeons. The total operation time, number of tool insertion, operating time in the lower calyces and the total time of additional tools insertion in the working channel were evaluated. In addition, surgeons evaluated the quality of imaging on a 5-point scale (a digital reusable ureteroscope was chosen as a reference standard).

Results. The average stones size was 13±4.07 mm (8-19). In 23 cases stones located in the lower calyx, 9 patients had pelvis stones. The total working time was 24 hours 53 minutes. The number of tool insertion through the working channel was 117 times. The working time in the lower calyces was 7 hours 34 minutes. The total time for the insertion of additional tools (laser fiber, baskets) in the working channel was 23 hours and 2 minutes. The quality of visualization was assessed by both surgeons as 4 points without its decreasing during the study period. The maximum upward deviation decreased from 270° to 258°, and the maximum downward deviation decreased from 270° to 252° (subjectively, the quality of bending of the endoscope did not deteriorate). There were no technical breakdowns and malfunctions during the study.

Conclusion. Our preliminary results confirmed high visualization quality, excellent strength and ergonomics of the new reusable fiber-optic ureterorenoscope «SemiFlex Scope».