During a ureteroscopy procedure that requires multiple passes of a flexible scope — such as retrieving several stone fragments or performing extensive laser lithotripsy — repeatedly threading the scope through the urethra, bladder, and ureter from scratch would be inefficient and could increase the risk of ureteral trauma with each pass. A ureteral access sheath addresses this by creating a temporary, protected conduit that stays in place for the duration of the case, functioning much like a highway that allows the scope to move in and out freely without renegotiating the entire urinary tract each time.
What Exactly Is a Ureteral Access Sheath and How Is It Placed?
A ureteral access sheath, often abbreviated UAS, is a dual-lumen tube consisting of an inner dilator and an outer sheath that is advanced over a previously placed guidewire, typically up into the mid or proximal ureter. Ureteral access sheath placement generally occurs early in a ureteroscopy case, after the guidewire confirms safe access to the ureter and before the flexible ureteroscope itself is introduced. Once positioned, the inner dilator is removed, leaving the outer sheath in place as a stable channel through which the ureteroscope can be passed and withdrawn repeatedly during the remainder of the procedure.
How Does a UAS Help Protect the Scope and the Ureter?
One of the more practical benefits associated with a ureteral access sheath is scope protection. Flexible ureteroscopes are delicate and expensive instruments, and repeated unprotected passage through the ureter can expose them to friction and bending stress that may shorten their working life or affect their deflection capability during a case. By providing a smooth, stable conduit, a UAS is generally understood to reduce the direct contact between the scope's outer surface and the ureteral wall during each pass. This same protective effect is also thought to reduce cumulative mucosal trauma to the ureter itself compared with repeated direct scope insertions without a sheath in place.
Why Does Irrigation Flow Matter During Ureteroscopy?
Adequate irrigation is essential during ureteroscopy for maintaining visibility, since the surgeon relies on continuous fluid flow to keep the field clear of blood, stone dust, and debris generated during laser fragmentation. A ureteral access sheath is generally understood to support improved irrigation flow and outflow around the scope, which can help maintain a clearer visual field throughout longer or more complex cases. This is particularly relevant during extended procedures where stone dust accumulation might otherwise progressively reduce visibility if fluid could not adequately clear the surgical field.
Is a Ureteral Access Sheath Used in Every Ureteroscopy Case?
Not necessarily. The decision to use a ureteral access sheath depends on factors such as anticipated procedure length, expected stone burden, whether multiple scope passes are likely, and ureteral anatomy, including its diameter and any prior narrowing. Smaller or more straightforward cases may not require a sheath, while more complex stone burdens or anticipated multiple retrieval passes often make sheath use more advantageous. A qualified physician determines whether and when to place a ureteral access sheath based on the individual case and anatomy, consistent with the device's Instructions for Use.
Access Sets Supporting Ureteroscopy Workflows
Ureteral access, whether through a guidewire, dilator, or access sheath, is a foundational step across many endourologic procedures. The Bionovus Ureteral Access Set supports ureteral access procedures, including the passage of instruments and scopes used during ureteroscopy and related interventions. It is offered as part of INVAMED's broader urology and incontinence management product range.
What is the purpose of a ureteral access sheath?
A ureteral access sheath creates a temporary protected pathway through the ureter that allows a flexible ureteroscope to be passed in and out multiple times during a single procedure without repeatedly navigating the full length of the urinary tract from scratch.
Does using an access sheath eliminate the risk of ureteral injury?
No. While a ureteral access sheath is generally understood to reduce certain types of repeated mucosal contact during multiple scope passes, it does not eliminate all procedural risk. Overall safety depends on ureteral anatomy, sheath sizing, and operator technique, all of which are assessed by the treating physician.
How is the correct ureteral access sheath size chosen for a procedure?
Sheath sizing is generally based on the diameter and length needed to accommodate the ureteroscope being used, along with the patient's ureteral anatomy. This determination is made by the treating urologist and procedural team based on preoperative planning and, when needed, intraoperative findings.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.