Novel Everting Urologic Access Sheath: Potential Advantages of Decreased Cellular Advancement

Abstract

Axial forces are imposed on the urothelium during advancement of instruments across the urinary tract, potentially transferring cellular debris, bacteria, or urothelial carcinoma from one anatomic location to another. A prototype access sheath (Cystoglide; Percutaneous Systems, Mountain View, CA) was created that everts and radially dilates but does not provide axial forces during deployment that can be used in a variety of anatomic systems. We created a urinary-tract model to evaluate the in-vitro advancement of cells to compare this technology with using instruments alone. Blocks of sterile agar were created with 17F tracts of three lengths (2.7, 5.5, and 11 cm) with 5 mL of Luria-Bertani broth/ampicillin solution in a well at the end. The tips of a Cystoglide sheath and a traditional urologic instrument of the same diameter were dipped into a suspension of ampicillin-resistant Escherichia coli and advanced through the tracts. After a 10-second exposure, 4 mL of broth was collected and cultured. Bacterial growth was compared by measuring the optical density (OD) of the broth at multiple time points. The mean overall OD of the broth was significantly lower (P < 0.001) in the novel-sheath cultures than with a traditional instrument for all advancements at all tract lengths. The Cystoglide sheath significantly reduces the advancement of cells within an artificial urinary tract compared with a non-everting instrument. Clinical studies are needed to assess the utility of this technology in vivo.