# Suction, flexion, and noise profile of three flexible and navigable suction ureteral access sheaths: a benchtop comparison

## TL;DR

This study compares three flexible suction ureteral access sheaths in a lab model to determine their performance in stone removal and maneuverability.

## Contribution

The study provides a direct benchtop comparison of three FANS devices, revealing differences in suction efficiency, deflection, and noise.

## Key findings

- Hoover and ClearPetra FANS outperformed Vathin in stone suction across all kidney trials.
- ClearPetra had the highest suction flow rates and was the quietest during operation.
- Hoover and Vathin showed greater deflection and lower deflection control force compared to ClearPetra.

## Abstract

Flexible and navigable suction ureteral access sheaths (FANS) have revolutionized treatment of urinary stones, and we hypothesized that different sheaths may have different functional characteristics. The purpose of this study was to compare 3 different FANS in a benchtop kidney/ureter model.

Three 12/14 Fr FANS were compared in a 3D-printed silicon kidney/ureter model: Dornier Hoover, Wellead ClearPetra, and Vathin. Randomized stone-suction trials were done in the upper, interpolar, and lower poles. Maximum deflection using 6.3 and 7.5 Fr flexible ureteroscopes, deflection control force, suction flow rates, and noise levels were also compared.

Hoover and ClearPetra FANS suctioned more fragments than Vathin when all kidney trials were considered (p < 0.01 for all). Comparing deflection, Hoover and Vathin had greater downward deflection compared to ClearPetra for both ureteroscopes (p < 0.005). Hoover upward deflection exceeded ClearPetra for both ureteroscopes (p < 0.008) and Vathin using the 6.3 Fr ureteroscope (p < 0.001). Deflection control force was less for Hoover and Vathin than ClearPetra at all angles in both directions (p < 0.001). Suction flow rates were higher for Hoover and ClearPetra compared to Vathin. At maximum deflection, ClearPetra flow rate exceeded Hoover (p < 0.001). ClearPetra was quietest during suction (54.5dB), while Vathin was loudest (74.0dB) (p < 0.001).

When comparing all kidney trials, Hoover and ClearPetra FANS outperformed Vathin in stone suction. Hoover and Vathin showed greater deflection and lower deflection force compared to ClearPetra. ClearPetra had higher flow rates and was quieter.