What this Trial Is About

Researchers are studying how sacral neuromodulation (SNM), a treatment for fecal incontinence (FI), affects the external anal sphincter (EAS) muscle. This project aims to understand the structure and function of the EAS and how SNM changes its morphology and biochemistry. SNM uses electrical stimulation of sacral nerve roots to help control continence and has shown positive short- and long-term effects, but its biological impact on the EAS is not well known. The study has three phases. The first phase involves taking biopsies from the EAS of patients with rectal cancer who have no history of FI and are undergoing abdominoperineal resection surgery. The second phase includes patients diagnosed with FI who are about to receive SNM treatment. Before implantation, they will have ultrasound and manometry tests and complete health and bowel function questionnaires. A biopsy of the superficial EAS is taken during the SNM test period under local anesthesia. The third phase involves repeating the ultrasound, manometry, and biopsy one year after SNM implantation. Participants will undergo various assessments including biopsies analyzed for tissue structure, cell types, and nerve and muscle features. Researchers will continuously analyze these biopsies over two years to measure the effects of SNM on the EAS. The study helps improve understanding of how SNM works, which may lead to better treatments for patients with FI.

Sacral Neuromodulation and Faecal Incontinence and Its Unknown Effect on the External Anal Sphincter