WallFlex Biliary PLUS RX Stent System

The WallFlex Biliary PLUS RX Stent System is an implantable self-expanding metal biliary stent pre-loaded on a delivery system. It is indicated for palliative treatment of biliary strictures caused by malignant neoplasms and relief of malignant biliary obstruction prior to surgery. The device consists of platinum-cored nitinol wires forming a cylinder with flares at both ends, fully covered with a Permalume coating.

The WallFlex Biliary PLUS RX device leverages the predicate WallFlex Biliary RX design with three primary differences: (1) reduced stent wire diameter, (2) a geometrically modified hilar flare, and (3) a larger duodenal flare. The devices otherwise share identical intended use, classification principles, and materials (nitinol construction with Permalume covering).

Performance testing was completed in accordance with FDA Guidance documents including Metal Expandable Biliary Stents - Premarket Notification (510(k)) Submissions (July 27, 2019), Technical Considerations for Non-Clinical Assessment of Medical Devices Containing Nitinol (July 9, 2021), and Testing and Labeling Medical Devices for Safety in the Magnetic Resonance (MR) Environment (October 10, 2023).

Boston Scientific demonstrated that the proposed WallFlex Biliary PLUS RX Stent System is substantially equivalent to the predicate WallFlex Biliary RX Stent System because both devices have identical intended use and principles of operation, and the design modifications (wire diameter, flare geometry) do not raise different questions of safety and effectiveness. Testing on the proposed device demonstrates substantial equivalence without clinical concerns, consistent with the predicate design's established safety profile.