Ureteral access sheath (UAS)
A hydrophilic-coated, kink-resistant plastic tube placed over a guidewire into the ureter before the flexible ureteroscope is passed through it.
How it is used
Facilitates repeated passage of the flexible ureteroscope into the kidney during retrograde intrarenal surgery (RIRS), protects the scope and reduces intrarenal pressure.
Clinical tip
Lowers intrarenal pressure and allows the scope to be withdrawn and reinserted without losing access, useful when multiple fragments must be removed.
Sources
This entry is part of the Instriq catalog, researched and written per specialty from real web research -- never generated or invented without verification -- and reviewed skeptically and independently before publication. How this catalog is written.
History
Added to the catalog on 2026-10-02.
Dates derived from the project's public version-control history on GitHub, not a live collaborative edit log.