Congenital anorectal atresia: MR imaging of late post-operative appearances in adult patients with anal incontinence

Abstract

To describe the MR imaging findings in adults presenting with anal incontinence following pull-through perineoplasty for anorectal atresia. 15 adults (12 male, 3 female; age 22-52 years) with anal incontinence following a prior perineal pull-through procedure as an infant for anorectal atresia were identified retrospectively. MR imaging was performed using either an endoanal coil or body coil. MR images were reviewed by three observers who noted whether pelvic floor and sphincter muscles were present and, if so, whether they were thinned or not. Data were tabulated and raw frequencies determined. Images were unavailable for one patient, leaving 14 for analysis. Anal stenosis prevented endoanal coil placement in 5. The pull-through was anatomically correct in 12 (86 %) patients but was misdirected in 2. Thinned muscle was seen in 11 (79 %) patients. External sphincter thinning was commonest (present in 10 patients), with levator plate thinning least common (present in 4 patients). Only one patient had thinning of all muscle groups. MR imaging may be used to determine the extent and quality of residual pelvic floor and anal sphincter muscle in adults who have functional disability following pull-through perineoplasty for anorectal agenesis.