To compare 2 digital flexible ureteroscopes in a randomized, prospective, clinical trial; the complementary metal oxide semiconductor–based Gyrus ACMI/Olympus Invisio DUR-D and the charged coupled device–based Olympus URF-V.

Patients scheduled for ureteroscopy were prospectively enrolled and randomized between the DUR-D and URF-V. Patient demographics, laser and total procedure time, laser energy, lower pole time, and difficulties encountered were recorded. The visibility and maneuverability were rated on a scale of 0-10.

A total of 101 patients (58 women) with a mean age of 49.5 years (20-80 years) were enrolled. Laser lithotripsy (mean stone size, 11.8 mm) was performed in 88 patients, 10 underwent stone basketing, and 3 had diagnostic ureteroscopy. For the DUR-D and URF-V, the mean total operative time (26.5 vs 25 minutes), laser time (12.5 vs 13 minutes), lower pole time (9 vs 11 minutes), and basket time (14.5 vs 13 minutes) were comparable. In 3 of 45 (6.6%) and 6 of 56 (10.7%) cases, the stone could not be reached with the DUR-D and URF-V, respectively. A fiberoptic scope (URF-P5) reached the stone in all cases. On a scale of 0-10, the mean visibility was 6.86 and 8.73 (P <.01) and the maneuverability was 7.18 and 8.17 (P <.01) for DUR-D and URF-V, respectively. There were 8 repairs, 4 for each scope. The DUR-D averaged 11.25 cases per repair and the URF-V averaged 14.

The URF-V offered better visibility and maneuverability compared with the DUR-D. Both had similar failure rates compared with the previous study with fiberoptic scopes.