Effect of estrogen replacement on the histologic response to polypropylene mesh implanted in the rabbit vagina model

Objective: The aim of this study was to determine the effect of estrogen replacement after ovariectomy on the histologic response to polypropylene mesh implanted in rabbit vagina. Study Design: Thirty rabbits were assigned to 5 groups: sham laparotomy, ovariectomy, ovariectomy-preoperative estrogen, ovariectomy-postoperative estrogen, or ovariectomy-preoperative and postoperative estrogen. Rabbits underwent sham surgery or ovariectomy and were infused with vehicle or 17β-estradiol (200 μg/d) for 4 weeks ("preoperative" estrogen). Polypropylene mesh was implanted in the posterior vaginal wall, and rabbits were infused with vehicle or "postoperative" estrogen for an additional 8 weeks. Grafts were harvested and underwent histologic evaluation. Results: Vaginal atrophy in ovariectomized rabbits was reversed by estrogen replacement. Scores for inflammation (P = .33) and neovascularization (P = .23) at the graft site were not different among estrogen replacement groups, but estrogen administration was associated with increased collagen deposition (P = .005). Conclusion: Estrogen replacement administered for 8 weeks postoperatively increases collagen deposition into polypropylene mesh.