Experimental stone clearance with in-scope suction and flexible and navigable suction access sheaths

Area of Science:

• Urology
• Endourology
• Medical Devices

Background:

• Ureteric stone management often involves fragmentation and clearance of residual stones.
• Direct in-scope suction (DISS) and flexible and navigable suction (FANS) are emerging technologies for stone fragment removal during ureteroscopy.

Purpose of the Study:

• To evaluate the stone clearance efficacy of DISS ureteroscopes and FANS ureteric access sheaths for various stone sizes.
• To compare the stone clearance capabilities of different ureteroscope working channel sizes and FANS in benchtop experiments.

Main Methods:

• Benchtop experiments were conducted using DISS ureteroscopes (3.6-Ch and 5.1-Ch) and FANS ureteric access sheaths.
• Stone mixes of progressively increasing sizes (up to 2000 μm) were used to test clearance efficacy.
• Suction was applied through the respective lumens until complete stone clearance failed.

Main Results:

• DISS with a 3.6-Ch working channel cleared stones up to 250 μm.
• DISS with a 5.1-Ch working channel cleared stones up to 500 μm.
• FANS successfully cleared all tested stone sizes up to 2000 μm.

Conclusions:

• DISS is effective for aspirating fine stone dust (<250 μm) during laser lithotripsy, potentially improving vision.
• Larger stone fragments (>250-500 μm) can obstruct ureteroscopes when using DISS.
• FANS demonstrates superior capability in clearing larger stone fragments, potentially facilitating overall stone burden removal.