Graft-related complications and biaxial tensiometry following experimental vaginal implantation of flat mesh of variable dimensions

Objective To compare the occurrence of graft-related complications (GRCs) and biomechanical properties of meshes implanted vaginally and abdominally. Design In vivo animal experiment. Setting Centre for Surgical Technologies, Medical Faculty, KU Leuven, Belgium. Population Twenty adult parous Texel ewes. Methods Sheep were implanted with Gynemesh M, a 28-g/m(2) polypropylene mesh reinforced with polyglecaprone fibres, under general anaesthesia. Dissection into the rectovaginal septum was performed to accommodate a flat 50 x 50 mm (n = 10) or 35 x 35 mm (n = 10) mesh, which was sutured to the underlying tissues. A 50 x 50 mm mesh was laid over a primarily sutured, full-thickness, 40-mm longitudinal abdominal wall incision. Sacrifice was at 60 days (n = 10) or 90 days (n = 5). Main outcome measures The occurrence of exposure, the degree of contraction and examination of the biomechanical properties of explants with a minimum radius of 32 mm via biaxial tensiometry. Results Insertion of a 50 x 50 mm mesh led to exposures in 30% (3/10) of cases, and the average contraction rate was 52 +/- 14%. In the 35 x 35 mm implants, there were no exposures, and the contraction rate was 25 +/- 26.3%. Vaginal explants with no GRCs and of sufficient size had biomechanical properties that were comparable with those of abdominal explants. Conclusion Vaginal mesh insertion is associated with GRCs, such as exposure and contraction. Although other factors probably play a role, this study illustrates that mesh size may also induce these complications. In a vaginal surgery model, clinically occurring GRCs can be reproduced. In addition, biomechanics of uncomplicated vaginal explants are comparable with those measured on abdominal explants.