Magnetic resonance imaging of the anal sphincter and spine in patients with anorectal malformations after posterior sagittal anorectoplasty: a late follow-up cross-sectional study

Purpose: We aimed to assess the association of fecal incontinence to the anatomy of the anal sphincter complex and lower bony spinal anomalies as investigated with magnetic resonance imaging (MRI) in adolescents and adults with anorectal malformations (ARM) after posterior sagittal anorectoplasty (PSARP). Methods: We conducted a cross-sectional study in 20 patients with ARM after PSARP. Anatomy of the anorectum and spine were examined with MRI and functional outcome assessed with the Wexner incontinence score. Results: We included 20 patient (12 males) had a median age of 19.5 years (14–27). One patient was excluded leaving 19 patients for outcome analysis. Fecal incontinence was found in 12 out of 19 patients (63%). Interposed fat was present in 9 patients (47%). The presence (r = 0.597, p = 0.012) and thickness of interposed fat (r = 0.832, p = 0.005) between the anal sphincter complex and bowel were positively correlated to the Wexner fecal incontinence score. No correlation was found between lower bony spinal anomalies and fecal incontinence. Conclusions: A positive correlation between interposed fat and higher Wexner fecal incontinence score was found indicating a more severe fecal incontinence but no other correlation between anatomy of the anal sphincter complex and neorectum to functional bowel outcome was observed.