Evaluation of the Impact and Need for Use of a Safety Guidewire during Ureteroscopy

The routine use of a "safety" guidewire adjacent to the ureteroscope during upper tract endoscopy is advocated in surgical texts and by many endourologists. Our experience has led us to theorize that a safety guidewire complicates ureteroscopy by providing resistance to introduction of the endoscope and by creating an obstruction to ureteroscopic instrumentation. To examine our theory, we developed a porcine animal model to evaluate the impact of the presence of a safety guidewire and reviewed our clinical experience, which routinely does not use a safety guidewire during ureteroscopy. An ex vivo model was created using the excised urinary tract of freshly slaughtered pigs. The forces needed to advance both a semirigid and flexible ureteroscope in the ureter were measured with and without the presence of a 0.035-inch safety guidewire. The clinical records of all patients undergoing ureteroscopy over a 4-year period were reviewed. On average, an additional 12 and 20 g of force were needed to introduce the semirigid and flexible ureteroscope when a guidewire was present. For the chosen study period, 361 patients underwent ureteroscopic procedures without the placement of a safety guidewire. No patient experienced an intraoperative complication related to the absence of a safety wire. The presence of a safety guidewire adjacent to the endoscope inhibits passage of the ureteroscope in an in vitro animal model. Technologic advancements in ureteroscope design and use of the holmium laser lithotrite minimize ureteral trauma and obviate the need for routine use of a safety wire during ureteroscopy.