A prospective survey evaluating the visual quality of KARL STORZ fiberoptic, digital, and disposable flexible...

To compare the visual quality amongst the disposable FLEX-XC1, digital FLEX-XC, and fiberoptic FLEX-X2S flexible ureteroscopes (FUS) and determine whether urologists can distinguish which FUS is in use.

In this prospective survey, 6 patients were prospectively randomized to the disposable FLEX-XC1, digital FLEX-XC, and fiberoptic FLEX-X2S FUS for retrograde intrarenal surgery (RIRS) for nephrolithiasis. Each RIRS was performed by a single-surgeon and recorded. 9 fellowship-trained endourologists were blinded to which FUS was used. They were asked to view the recordings, answer which FUS was used, and fill out a 7-question survey grading parameters from 0 to 5. Statistical analysis was performed with SPSS. ANOVA with Tukey's posthoc analysis confirmed significance defined as p < 0.05.

78%, 89%, and 78% of endourologists correctly identified which FUS was used between the disposable FLEX-XC1, digital FLEX-XC, and fiberoptic FLEX-X2S FUS's respectively. The digital FUS outperformed the others in overall score (p < 0.001). The only visual parameter that was not statistically different amongst FUS's was Laser Activation Interference (p = 0.97). After Tukey's posthoc analysis, the digital FUS outperformed the fiberoptic scope in all parameters except LAI. The disposable FUS outperformed the fiberoptic scope in all parameters except for LAI, tissue interference (TI), and overall impression. The digital FUS was superior to the disposable FUS only in Visual quality (Color) and TI.

The majority of fellowship-trained endourologists can distinguish which type of KARL STORZ FUS is in use. The KARL STORZ digital and disposable FUS's outperform the KARL STORZ fiberoptic FUS in nearly all visual parameters. The KARL STORZ disposable FUS is comparable to the KARL STORZ digital FUS except for Visual Quality (Color) and Tissue Interference.

This study was approved by the Northwestern Institutional Review Board and was assigned study ID STU00217933. It is also registered under NCT05646069, titled "Evaluation of Novel Disposable Flexible Ureteroscope for the Treatment of Renal Calculi."