RESUMO
INTRODUCTION: Stress urinary incontinence (SUI) is one of the health problems with more impact on patients' lives. The aim of the present work was to develop a therapy for SUI using tissue engineering by isolation and culture of autologous myoblasts (CAM) followed by endoscopic implantation. We also evaluated the efficacy of this therapy in a rabbit model of incontinence after sphincterotomy. MATERIALS AND METHODS: We used healthy male New Zealand rabbits. The animals were first bled to obtain platelet-poor plasma (PPP) and biopsied for myoblast isolation. Post-sphincterotomy, they were divided into two groups: the treatment group (including animals that received CAM resuspended in PPP) and the control group (including animals receiving only PPP). The leak-point pressure (LPP) was used to measure continence in both groups at different time points. The results were evaluated with hierarchical linear regression models. Histological evaluation of the rabbits' sphincters was also performed at the end of follow-up. RESULTS: No statistically significant differences were observed between the baseline LPP values of each group. The post-sphincterotomy values of both groups were below 50% of the baseline value, which was a mandatory condition for incontinence. The post-implantation values of the treatment group were higher than 50% of the baseline value, which led us to assume continence recovery. A statistically significant difference was observed in the LPP values between the two treatment groups (p=0.003). Histological study revealed interconnected islands formed by muscle fibers in the treatment group, and connective tissue surrounding the urethral lumen and inflammatory infiltrate in the control group. DISCUSSION AND CONCLUSIONS: The implantation of CAM significantly improved LPP values in the treatment group, and the improvement remained throughout the evaluation period. It may be associated with the consistency of the implant and its stability at the injection site. Longer follow-up studies and human clinical investigations are required to consider CAM implantation as an alternative treatment for stress urinary incontinence.
