Dynamic magnetic resonance imaging evaluation of the structural and functional results of postanal repair for neuropathic fecal incontinence.

PURPOSE: The aim of this study was to determine whether dynamic magnetic resonance imaging of the pelvic floor can discriminate between patients who improve after postanal repair for neurogenic fecal incontinence and those who remain symptomatic.
METHODS: Pelvic floor measurements obtained during dynamic magnetic resonance imaging in eight females whose anal incontinence had improved after postanal repair were compared with those from nine females who remained symptomatic. All subjects also underwent standard anorectal physiology testing.
RESULTS: There was no significant difference between groups with respect to any measurement of anterior or middle pelvic floor compartments. Additionally, there was no difference in posterior pelvic floor configuration when symptomatic patients were compared with those who had improved. However, dynamic magnetic resonance measurements revealed patients who remained symptomatic had significantly greater posterior pelvic floor weakness. Anorectal physiology was unable to differentiate between groups.
CONCLUSIONS: There is no difference in static pelvic floor measurements when subjects remaining symptomatic after postanal repair are compared with those who have improved. In contrast, dynamic measurements may be able to predict failure in those who demonstrate excessive posterior pelvic floor mobility.