Retrograde intrarenal surgery using flexible ureteroscope has become the first-line treatment for renal calculi < 3.0 cm and is recommended by the European Association of Urology due to its minimally-invasive nature and satisfactory result.~However, some limitations still remain. Poor maneuverability, extra costs for the ureteral access sheath, and high device vulnerability still preclude flexible ureteroscopy from wider distribution.~Recently, the investigators present a novel ureterorenoscope, which is composed of a retractable rigid sheath and a semi-rigid ureteroscope with a flexible part on the tip. When the flexible tip of the inner shaft maintains within the sheath, working in the rigid mode, the tip-flexible semi-rigid ureterorenoscope is capable of passing either the orifice or the physiological tortuosity of the ureter with ease. When the inner shaft is extended beyond the sheath, the endoscope is switched to the flexible mode, capable of performing an intrarenal approach.~This endoscope integrates the classic semi-rigid and flexible ureteroscope both structurally and functionally, and has been approved for clinical application by the China Food and Drug Administration. In this study, transverse comparison is designed to evaluate the safety and efficacy of the tip-flexible semi-rigid ureterorenoscope for the treatment of renal calculi.
This study evaluates the safety and efficacy of the novel tip-flexible semi-rigid ureterorenoscope for the treatment of renal calculi using a prospective, randomized multicentre trial design. Half of participants will receive retrograde intrarenal surgery using the tip-flexible semi-rigid ureterorenoscope, while the other half participants will receive retrograde intrarenal surgery using the classic flexible ureteroscope.