Variables affecting deflection of a new third-generation flexible ureteropyeloscope (DUR-8 elite)

We performed an ex vivo study to measure the effects of various factors on the deflection angles of a new flexible ureteroscope with active primary and secondary deflections.

Active primary and secondary deflections in different sequences were measured initially without working devices (baseline measures). Nine different working instruments were then placed in the working channel, and alterations in ureteroscope deflectability were measured.

Baseline measures showed excellent angles of deflections, consistent with the manufacturer's reporting. Among the wires tested, only the stiff wire had a negative (minor) impact on deflectability. There were similar minimal decreases of deflection with baskets. The 1.6F electrohydraulic lithotripsy (EHL) probe had minimal influence on deflectability compared with the 3.0F EHL probe. The 200-microm and 365-microm laser fibers significantly (>20 degrees ) decreased the angles of deflection.

In spite of the changes in deflectability with almost all working instruments, there were no significant decreases in the angles with most of them. The sequence is important in obtaining optimal deflection.