Intrarenal manipulation of flexible ureteroscopes: a comparative study

Area of Science:

• Urology
• Medical Devices
• Surgical Technology

Background:

• Flexible ureteroscopes (FUs) are crucial for intrarenal surgery.
• Newer FUs offer enhanced active deflection for improved manipulation.
• Comparative studies are needed to evaluate the performance of different FUs.

Purpose of the Study:

• To compare the manipulation ease of four flexible ureteroscopes (FUs) in a calyceal model.
• To assess the performance of new-generation FUs with exaggerated active deflection.
• To evaluate the impact of surgeon experience on FU performance.

Main Methods:

• Four FUs (<7.5 F) were tested: Viper, FlexVision U-500 (SF), Dur-8 Elite (D8E), and URF-P3.
• Eight experienced ureteroscopists performed standardized navigation tasks in a calyceal model.
• Objective (time) and subjective (ease of manipulation) data were collected.

Main Results:

• The Viper demonstrated the fastest mean total manipulation time (29s), followed by SF (37s), D8E (38s), and URF-P3 (50s).
• The Viper was significantly quicker in reaching the posterior middle pole compared to other FUs.
• Subjectively, six of eight endoscopists preferred the Viper for ease of manipulation, while the URF-P3 was rated most difficult.

Conclusions:

• Flexible ureteroscopes with exaggerated active deflection outperformed the URF-P3 in a calyceal model with limited passive deflection.
• The Viper showed superior maneuverability and was preferred by experienced endoscopists.
• Advanced active deflection is key for efficient intrarenal manipulation.