The role of endoluminal imaging in clinical outcome of overlapping anterior anal sphincter repair in patients with fecal incontinence.

OBJECTIVE. Anterior sphincter repair has become the operation of choice in patients with fecal incontinence who have defects of the external anal sphincter (EAS), but not all patients benefit from surgery. The aim of this study was to investigate whether endoluminal imaging can identify determinants that play a role in the outcome of sphincter repair. SUBJECTS AND METHODS. Thirty fecal incontinent patients with an EAS defect were included. The severity of incontinence was evaluated pre- and postoperatively using the Vaizey incontinence score. Patients underwent endoanal MRI and endoanal sonography before and after sphincter repair. We evaluated the association between preoperatively assessed EAS measurements with outcome and postoperatively depicted residual defects, atrophy, tissue at overlap, and sphincter overlap with clinical outcome. RESULTS. After surgery, the mean Vaizey score in 30 patients (97% females; mean age, 50 years) had improved from 18 to 13 (p < 0.001). MRI showed that baseline measurement of preserved EAS thickness correlated with a better outcome (r = 0.42; p = 0.03). Clinical outcome did not differ between patients with and those without a persistent EAS defect ( p = 0.54) or EAS atrophy (p = 0.26) depicted on MRI. Patients with a visible overlap and less than 20% fat tissue had a better outcome than patients with nonvisible, fatty overlap (decrease in Vaizey score, 7 vs 2 points, respectively; p = 0.04). Sonography showed that patients with a persistent EAS defect had a worse outcome than those without an EAS defect (17 vs 10 points, respectively; p = 0.003). CONCLUSION. Endoanal MRI was useful in determining EAS thickness and structure, and endoanal sonography was effective in depicting residual EAS defects.