A Novel Surgical Technique in a Sheep Model for Suburethral Graft Implantation.

Abstract

Suburethral polypropylene mesh tapes for women were initially introduced into clinical practice for the treatment of stress urinary incontinence without being tested in an appropriate animal model. The goal of this work has been to establish and evaluate a suitable animal model for the assessment of suburethral tape grafts. Allowing for the anatomical similarities between ewes and women and recognizing the inevitable differences in posture, but recognizing prior work, this report presents a step-by-step description of the surgery involved in an animal model that simulates the implantation of support materials for treating stress urinary incontinence in women. Seven ewes with a mean weight of 27.7 SD 5.1 kg underwent surgery. In the lithotomy position, a ventral vaginal wall incision was made. In five animals, using an introducer, a polyurethane implant was placed underneath the urethra and fixed with absorbable sutures. The incision was closed, and a betadine vaginal pack was placed after 24 h. Two animals received transvaginal polypropylene mesh using similar surgical steps but no fixation sutures. After surgery, all animals urinated freely and had regular bowel movements. No animals showed signs of vaginal erosion or graft infection during the three-month follow-up. This large animal model accurately reproduces the surgical technique used in women, thereby providing a valuable platform for evaluating new materials for stress urinary incontinence treatment.