Endourology and Stones Safety and Efficacy of a Novel Ureteral Occlusion Device Carl Sarkissian, Adrian Paz, Ofer Zigman, Kate Webster, Idan Tamir, and Manoj Monga OBJECTIVE To evaluate the safety of a novel ureteral occlusion device and compare its performance with that of other devices and guidewires. METHODS The XenX (Xenolith Medical) was tested in an ex vivo porcine model to determine the percentage of denuded urothelium because of manipulation within the ureter, the capacity to prevent stone migration during laser lithotripsy, stent compatibility, and the ability to be used for stent placement. Comparative evaluations of the insertion forces and maneuverability were conducted in an in vitro ureter model with the XenX, Stone Cone (Boston Scientific), NTrap (Cook Urological), HiWire (Cook Urological), Roadrunner (Cook Urological), and Sensor (Boston Scientific). Stone migration efficacy was measured using a controlled distribution of stones in 4- and 10-mm silicone tubing with the XenX, NTrap, and Stone Cone. RESULTS The XenX was safely manipulated within the ureter, prevented significant particle migration during laser lithotripsy, and effectively placed stents. The NTrap required the greatest force when attempting to navigate past a stone (P = .0003), followed by the Stone Cone (P = .009), with little difference among the other devices (P  .72). No differences were found for the passing forces (P = .061), interval to pass (P = .30), or number of attempts to pass the stone (P = .68). The XenX prevented stone migration the most, with more notable differences in the 10- than in the 4-mm tubing. CONCLUSION Ex vivo evaluations hold promise for the XenX to be safely and effectively used during ureteroscopic procedures. Clinical evaluations are warranted to confirm the safety and perfor- mance of the XenX relative to the other ureteral occlusion devices. UROLOGY 80: 32–37, 2012. © 2012 Elsevier Inc. T he ability to prevent stone retropulsion during intracorporeal lithotripsy remains an issue in which improvement can dramatically affect the overall efficiency of ureteroscopic stone extraction. Al- though American Urological Association guidelines sug- gest that the stone-free rate for the ureteroscopic treat- ment of mid and distal ureteral calculi is 86%-94% with low morbidity, the necessity to reduce the operative times, complications, and costs remains a challenge. 1,2 During the past decade, increasing attention has been placed on the use of ureteral occlusion devices to prevent migration of stone fragments during ureteroscopic and percutaneous stone extraction procedures, with the 3 most successfully reported devices being the Stone Cone (Boston Scientific, Boston, MA), Accordion (Percsys, Mountainview, CA), and NTrap (Cook Urological, Spencer, IN). 3-7 Clinical studies of the Stone Cone and NTrap have indicated significant improvements for the intraoperative and postoperative markers of success (stone migration, stone-free rate, incidence of trauma, and the need for stenting or a secondary procedure); however, the limitations of these devices suggest the ideal device has yet to become available. 5,8-11 Currently, none of the available stone migration de- vices are able to serve the dual purpose of an occlusion device and a guidewire over which a stent can be placed at the completion of the procedure. This presents the advantage of passing only 1 device past an impacted stone in a diseased ureter. The ideal device should effec- tively prevent the passage of all stone fragments, regard- less of size, lithotripsy modality, irrigation pressure, and extent of ureter dilation. The ideal device should effec- tively prevent the passage of all stone fragments, regard- less of stone size, lithotripsy modality (pneumatic vs. laser), irrigation fluid pressure, or extent of ureteral dila- tion. In the present study, we evaluated the safety of a novel ureteral occlusion device, the XenX (Xenolith Financial Disclosure: A. Paz and K. Webster are paid consultants to Xenolith Medical Ltd; O. Zigman is an employee of Xenolith Medical Ltd; I. Tamir is a board member of Xenolith Medical Ltd; M. Monga is a study investigator funded by Xenolith Medical Ltd. and a paid consultant to Boston Scientific, Cook Urological, Bard Urological, and Gyrus ACMI. K. Webster is a former employee of Virginia Biosciences Commercialization Center. From the Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio; Xenolith Medical, Ltd., Kiryat-Gat, Israel; and Virginia Biosciences Commer- cialization Center, Richmond, Virginia Reprint requests: Manoj Monga, M.D., Glickman Urological and Kidney Institute, Cleveland Clinic, 9500 Euclid Avenue, Q10-1, Cleveland, OH 44195. E-mail: mongam@ccf.org Submitted: October 24, 2011, accepted (with revisions): March 13, 2012 32 © 2012 Elsevier Inc. 0090-4295/12/$36.00 All Rights Reserved http://dx.doi.org/10.1016/j.urology.2012.03.018