The position of the working channel in a flexible ureteroscope can greatly impact the success and efficiency of surgical procedures. In this study, we aimed to compare different flexible ureteroscopes based on their working channel positions(WCP) and evaluate their performance in flexible ureteroscopy.

An experienced endourologist performed navigation and stone interaction tasks in a 3D-printed kidney model using four scopes with different WCP. Completion times, the percentage of dots reached, wrist range of motion, and operator fatigue were recorded.

Flex Xc (3 o’clock) * superior task completion times and percentages of dots reached in specific calyces * excellent efficacy for right lower kidney stones * greater operator fatigue Lscope (9 o’clock) * longer completion times and lower interaction rates in the right kidney * excellent efficacy for left lower kidney stones * better wrist extension ROM URUS (6 o’clock) * ergonomic and comfortable * efficient in accessing lower posterior calyces * excellent stone control and fiber manipulation Lithovue (3 o’clock) * performed well but without significant differences from other scopes

Our findings provide valuable data to guide the selection of appropriate scopes to enhance efficacy and ergonomics associated with the RIRS procedure. The in vitro results also offer recommendations for optimal working channel positions in different clinical scenarios, ultimately leading to improved clinical practices and patient satisfaction