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 flexible ureteroscopy have been introduced. In this study, we compare currently available disposable digital and fiberoptic flexible ureteroscopes with a contemporary reusable fiberoptic device. Materials and 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 (1) visualization of all calices (correct assignment of colored pearls) and (2) the extraction of human calculi with a standard disposable extraction device (NGage®). We documented the effective visualization, stone extraction, and times to completion. In addition, the surgeons' workload and performance were determined using the National Aeronautics and Space Administration-Task Load Index. Results: In visualizing and identifying calices, the LithoVue and both generations of the Uscope performed similarly, but time to completion was significantly longer for all single-use devices in comparison with the Boa Vision. 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 (73 vs 102 seconds/stone). This disadvantage has, however, been overcome with the new Uscope Generation UE3022, showing a retrieval time of only 65 seconds per stone, excelling over the reusable scope in this category. The Uscope UE3022 image quality was also rated best, but showed no significant difference. Conclusions: In comparison with disposable ureteroscopes available, LithoVue offers 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 with the LithoVue's.

Performance of Single-Use FlexorVue vs Reusable BoaVision Ureteroscope for Visualization of Calices and Stone Extraction in an Artificial Kidney Model.

PURPOSE: To evaluate and compare Flexor®Vue™, a semidisposable endoscopic deflection system with disposable ureteral sheath and reusable visualization source, and a nondisposable fiber optic ureteroscope in a standard in vitro setting. MATERIALS AND METHODS: FlexorVue and a reusable fiber optic flexible ureteroscope were each tested in an artificial kidney model. The experimental setup included the visualization of colored pearls and the extraction of calculi with two different extraction devices (NCircle® and NGage®). The procedures were performed by six experienced surgeons. Visualization time, access to calices, successful stone retraction, and time required were recorded. In addition, the surgeons' workload and subjective performance were determined according to the National Aeronautics and Space Administration-task load index (NASA-TLX). We referred to the Likert scale to assess maneuverability, handling, and image quality. RESULTS: Nearly all calices (99%) were correctly identified using the reusable scope, indicating full kidney access, whereas 74% of the calices were visualized using FlexorVue, of which 81% were correctly identified. Access to the lower poles of the kidney model was significantly less likely with the disposable device, and time to completion was significantly longer (755 s vs 153 s, p < 0.001). The stone clearance success rate with the disposable device was 23% using the NGage and 13% using the NCircle basket. Overall NASA-TLX scores were significantly higher using FlexorVue. The conventional reusable device also demonstrated superior maneuverability, handling, and image quality. CONCLUSIONS: FlexorVue offers a semidisposable deflecting endoscopic system allowing basic ureteroscopic and cystoscopic procedures. For its use as an addition or replacement for current reusable scopes, it requires substantial technical improvements.