Phasix ST Umbilical Hernia Patch

The Phasix™ ST Umbilical Hernia Patch is a sterile, single-use surgical mesh device for reinforcing soft tissue weakness during umbilical hernia repair. It is a self-expanding, fully resorbable mesh made of poly-4-hydroxybutyrate (P4HB) with a resorbable hydrogel coating, a positioning pocket, and a strap containing a polydioxanone (PDO) ring for memory and stability.

The mesh comprises two layers of P4HB co-knitted with polyglycolic acid (PGA) fibers and coated with a resorbable hydrogel (sodium hyaluronate, carboxymethylcellulose, and polyethylene glycol). Key differences from predicates include: hybrid positioning straps combining P4HB and polypropylene (versus polypropylene-only in Ventralex ST), a blue-dyed delineation marker on the straps, and the absence of a pre-attached removable positioning system (unlike Phasix ST Mesh with Open Positioning System).

ISO 10993-1 (Biological evaluation of medical devices – Part 1: Evaluation and testing within a risk management process, September 8, 2023) guided biocompatibility testing. Testing included material chemical characterization, cytotoxicity, sensitization, irritation, acute systemic toxicity, pyrogenicity, subacute and subchronic toxicity, genotoxicity, and implantation studies.

The device is substantially equivalent because it has identical intended use, materials (mesh component identical to secondary predicate Phasix ST Mesh with Open Positioning System), packaging, and sterilization method as the predicates. Although hybrid positioning straps differ from Ventralex ST's polypropylene-only design, bench testing of these differences (ball burst strength, suture retention, tear strength, strap attachment strength, etc.) demonstrated performance and safety comparable to predicates. Biocompatibility testing addressed the new material combination (P4HB and PDO) and confirmed no adverse interactions. Animal study data from the predicate devices supports in-vivo safety for the identical mesh materials.