Current disposable ureteroscopes - performance and limitations in a standardized kidney model.

OBJECTIVES Due to the increasing fragility of the instruments and rising concerns about the sterility of reprocessable scopes, several single-use devices for fURS have been introduced. In this study we compare currently available disposable digital and fiberoptic flexible ureteroscopes with a contemporary reusable fiberoptic device. METHODS LithoVue™, Pusen Uscope® (UE3011, UE3022), Flexor®Vue™ and a reusable fiber optic flexible ureteroscope (BOA vision®) were tested in kidney models. The setup included (a) visualization of all calices (correct assignment of colored pearls) and (b) the extraction of human calculi with a standard disposable extraction device (NGage®). We documented the successful visualization, stone extraction, and times to completion. In addition, the surgeons' workload and performance was determined using the NASA-Task Load Index (NASA-TLX). RESULTS In visualizing and identifying calyces, the LithoVue and both generations of the Uscope performed similarly, but time to completion was significantly longer for all single-use devices in comparison to the BoaVision. LithoVue retracted stones almost as well as the reusable scope (97% vs 95%/82%/96% stone clearance), while accessibility was impeded using Uscope UE3011, as reflected by the retrieval time per stone (73s vs. 102s per stone). This disadvantage has, however, been overcome with the new Uscope Generation UE3022, showing a retrieval time of only 65s/stone, excelling over the reusable scope in this category. The Uscope UE 3022 image quality was also rated best, but showed no significant difference. CONCLUSIONS In comparison to disposable ureteroscopes available, LithoVue offers a performance and characteristics similar to a reusable device, while the FlexorVu's performance does not yet yield satisfactory results for clinical use. The first generation of Uscope exhibits potential, but requires further technical improvements to match the performance of a reusable device. With the new generation UE3022 Pusen has made significant improvement and offers a quality comparable to the LithoVue's.