Amy E. Krambeck, MD, highlights the advantages of flexible and navigable ureteric access sheaths

In this video, Amy E. Krambeck, MD, a professor of urology at the Northwestern University Feinberg School of Medicine in Chicago, Illinois, discusses how flexible and navigable ureteric access sheaths (FANS) differ from conventional designs and how they have transformed the efficiency of stone removal during ureteroscopy.

Traditional ureteral access sheaths are rigid, hollow tubes that simply act as conduits to facilitate passage of the ureteroscope between the bladder and kidney. In contrast, the newer flexible suction sheaths are softer, longer, and feature a deflectable tip that can be navigated into various renal calyces, including the lower pole. This flexibility enhances access to difficult-to-reach areas of the kidney.

The suction function represents another major advancement. These sheaths connect to suction tubing that allows the surgeon to dynamically control suction strength during the procedure. Light suction can be used while lasering stones, and stronger suction can be applied to extract fragmented pieces efficiently. The tubing directs the material into a catch container, allowing for easy stone retrieval and post-procedure analysis.

Krambeck notes that evidence from European centers—where flexible suction sheaths have been in use longer—demonstrates significant improvements in stone-free rates. Multicenter studies show rates as high as 98% to 99% when defining stone-free as residual fragments ≤2 mm, compared with 50% to 60% using conventional access sheaths. Although achieving a true 100% stone-free rate remains unrealistic due to imaging limitations and minute calcifications visible on CT, the improvement with suction sheaths is clinically meaningful.

Overall, Krambeck highlights that FANS combine enhanced maneuverability and effective fragment evacuation, leading to higher stone clearance rates and improved procedural outcomes in endourology.