Structural differences and architectural features of two different polypropylene slings (TVT-O and I-STOP) have no impact on biocompatibility and tissue reactions

INTRODUCTION: To evaluate the impact of design features of the synthetic mid-urethral slings on tissue integrity and inflammatory responses. MATERIAL AND METHODS: In total 30 female Sprague-Dawley rats were implanted with type I monofilamentous, macroporous polypropylene meshes: Gynecare TVT-Obturator tape(®) (Ethicon Inc., Johnson & Johnson, Somerville, NJ, USA) and I-STOP(®) (CL Medical Inc., Lyon, France). All animal groups were sacrificed at set time intervals – 6 weeks, 3 months, 6 months, 9 months and 12 months – and the abdominal wall was harvested with mesh strips for histological evaluation. RESULTS: All mesh strips appeared to be well incorporated into the abdominal wall, and no signs of shrinkage was noticed. All specimens showed a thin/delicate, loose, fibrous interface between the synthetic graft plate and abdominal wall, along with mild inflammatory reactions from 6 weeks to 12 months. CONCLUSIONS: Both mesh brands induced comparable, minimal foreign body reactions and integrated well into the host tissues despite differences in architectural features. TVT-O(®) and I-STOP(®) evoked similar low-grade inflammatory responses up to 12 months in this animal model. Structural differences and architectural features of polypropylene slings used in this study have had no impact on tissue integrity and inflammatory responses.