Stress urinary incontinence (SUI) is the involuntary urine leakage with increased intra-abdominal pressure. The standard surgical treatment involves placement of a polypropylene (PP) mid-urethral sling (MUS). While effective, PP implants are associated with tissue ingrowth, often leading to difficult mesh removals and increased morbidity when revision or explantation is required. There remains a need for alternative effective materials offering improved removability and biocompatibility. The objective of this project is to evaluate the biocompatibility, stability, and removability of a novel, application-specific, expanded polytetrafluoroethylene (ePTFE) MUS in a porcine model.
The ePTFE MUS, developed specifically as a MUS device by RebedaTek, LLC, has cross-sectional pore size less than 1 µm, making it impervious to bacteria, minimizing infection and erosion, and increasing ease of extraction. Pledgets made from fluorinated ethylene propylene (FEP), a durable, chemically inert compound, were attached at both ends of the MUS as anchors. An ePTFE MUS was implanted in each of 6 female Yucatan mini-pigs (30–50 kg). Through a small vaginal incision, the MUS was positioned in the mid-urethral region and anchored bilaterally to the obturator membrane using the FEP pledgets. Excess MUS length was rolled into the periurethral space to simulate clinical placement. After twelve weeks, slings were explanted, and the time required for removal was recorded. Tissue specimens surrounding the MUS body and anchor sites were collected for histologic assessment. Comparable tissues from a single control animal were collected. Study endpoints included technical feasibility of implantation, evidence of migration, ease of removal measured by explantation time and biocompatibility assessed as evidence of inflammation and fibrosis.
After 12 weeks of implantation, all animals remained healthy with no procedure-related adverse effects and no evidence of migration. Explantation times were short (mean of 12.4 ± 2.84 seconds) with minimal gross tissue adhesions. Histologic evaluation revealed no inflammation and only mild fibrosis in the periurethral region and at the obturator muscle. MUS extrusion into the vagina was observed in three animals at the time of removal, which appeared related to the excess MUS length rather than material properties. There were no signs of infection or inflammation at the extrusion site.
The novel ePTFE MUS demonstrated favorable biocompatibility and ease of removal in a porcine model, with minimal inflammation, fibrosis, or tissue adhesion. These findings suggest that ePTFE may offer a promising alternative for MUS applications.
