Effects of Steris 1™ sterilization and Cidex® ortho-phthalaldehyde high-level disinfection on durability of new-generation flexible ureteroscopes

Background and Purpose: The effects of commonly used reprocessing methods on flexible ureteroscope longevity have never been examined. We prospectively studied the effects of Steris 1(TM) sterilization and Cidex(R) ortho-phthalaldehyde (OPA) high-level disinfection (HLD) on the image quality, physical structure, and deflective properties of two new flexible ureteroscopes. Materials and Methods: Two identical "out-of-the-box" Storz 11278AU1 flexible ureteroscopes (Karl Storz Endoscopy, Tuttlingen, Germany) were sterilized individually using the Steris 1(TM) system (Steris Mentor, Ohio) or disinfected with Cidex(R) OPA (Advanced Sterilization Products, J&J, Irvine, CA) for 100 trials followed by a crossover to the other method for another 100 trials over a period of 1 year. After every five trials, optical quality, angle of deflection, and fiber damage were analyzed in the laboratory. Throughout the study, neither of these ureteroscopes was used clinically. Results: After 100 trials, ureteroscope 1, which was sterilized initially in the Steris system, had a 12-mm tear on its shaft (noted after the 17(th) trial), 297 damaged fibers, and a 37% drop in resolution (loss of 3.75 lines/mm). There was no change in deflection from baseline. In contrast, after 100 cycles, ureteroscope 2, which was subjected to HLD with Cidex(R) OPA, had no visible external damage, a 0% change in resolution, 10 damaged fibers, and no change in deflection. After the crossover, ureteroscope 2 developed a semilunar defect that obscured the endoscopic view, whereas there was no further significant damage to ureteroscope 1. Conclusion: After 100 cycles, the Steris 1 system rendered the flexible ureteroscope unusable, whereas HLD with Cidex(R) OPA had minimal adverse impact.