Traxer and colleagues performed a study to evaluate the flexibility of different ureteroscopes in the management of lower pole calyx stones.
Authors performed an in vitro study to assess the flexibility of multiple scopes. They developed a training model for flexible ureteroscopy, and identified an acute angle calyx and tried to access it with 9 different ureteroscopes. The scopes assessed in this study included BOA vision and COBRA vision, Richard Wolf®; FLEX X² and FLEX Xc, Karl Storz®; LithoVue, Boston Scientific®; URF-P5, URF-P6, URF-V and URF-V2, Olympus®. Passing the scope through a 10/12 Fr ureteral access sheath respectively (using ReTrace®, Coloplast sheath) (except 12/14 Fr sheath for COBRA vision), with the tip out at 1 cm, 2 cm, 3 cm and 4 cm, they measured the maximum tip deflection for every ureteroscope.
The study demonstrated that all optical ureteroscopes (URF-P5, FLEX X²) except the URF-P6 were able to access the sharp angled calyx. Except FLEX Xc, none of the digital ureteroscopes reached the difficult calyx. Overall, all optical ureteroscopes had better end-tip deflection compared to the digital scopes with the exception of FLEX Xc, which was as deflectable as the optical ureteroscopes.
Authors concluded that the contemporary digital ureteroscopes tend to be more rigid and the tip of the instrument has shown to be less flexible. This is a significant limitation when it comes to the management of lower pole stones. This limitation of technology is possibly due to the size of the camera capsule. When approaching a difficult, acute angled lower pole calyx, it might be better to use a fiberoptic ureteroscopes, which have been shown to be more flexible due to the lack of the camera chip on the tip.
Speaker(s): Dragos, MD
Authors: Dragoş L.B., Buttice S., Sener E.T., Proietti S., Ploumidis A., Iacoboaie C., Doizi S., Berg J., Somani B., Traxer O.
at the #EAU17 - March 24-28, 2017- London, England