Breaking the Scope Port Size Barrier: A New Kind of Endoscope that Removes Large Kidney Stones Rapidly

Project Summary/Abstract: The objective of this proposal is to create a new kind of flexible ureteroscope that transforms nearly instanta- neously from endoscope to large-lumen steerable suction catheter to enable rapid removal of large kidney stone volumes, sparing patients from invasive alternatives. Clinical significance comes from the 3.5 million patients who suffer from kidney stones each year in the USA alone, 700,000 of whom have interventional procedures done to remove the stones. 230,000 of these people have larger kidney stone volumes, and thus are subject to either invasive surgery or excessively long ureteroscopy, with its increased complication rates and excessive procedure durations. Our central hypothesis is that our new transformable ureteroscope will reduce the procedure time by 36 minutes or more for patients with large stone volumes. Reducing procedure duration by this much will make larger stone times equivalent to small stone times, making many more patients candidates for minimally invasive interventions. Innovation comes from a new mechanical actuation concept that enables us to build bending actuation directly into the outer wall of the device itself. This enables an open central lumen that is nearly as large in diameter as the endoscope itself. The lumen initially carries a camera/illumination core that can be removed whenever desired to transform the device into a steerable suction sheath. To build bending actuation into the outer wall, we harness elastic interactions in asymmetrically stiff, thin-walled tubes. After attaching these tubes at their tips, tip bending can be created through small relative linear displacement at the tube bases. The result is a highly dexterous device with the same bending capabilities of a ureteroscope that has a large central lumen for high volume stone removal via suction. Our approach in Aim 1 is to design, optimize and build an OR-ready version of our steerable sheath and insertable camera/illumination core using scalable manufacturing processes and clinical-grade, biocompatible materials. The goal of Aim 2 is to create the user interface of the steerable section and the removable cam- era module, culminating in a low-volume production run with production-equivalent materials, and to perform comprehensive formative human factors evaluations of the Aspire system. Aim 3 focuses on statistically pow- ered experiments to evaluate our hypotheses that our new steerable suction scope will reduce average surgical duration by 38%, while also demonstrating a reduction in surgical duration of very large stones and improv- ing stone-free rates. This will bring times and stone free rates for patients with larger stones in line with the current (small stone) standard of care, so that they can be treated within clinical guidelines for maximum safe ureteroscopy duration. Success in validating these hypotheses will strongly motivate future Phase III activities (supported by private capital after the conclusion of this Phase II SBIR) where we complete the FDA 510(k) clearance process, and launch our device on the market.