Fecal incontinence in females with a past history of vaginal delivery: significance of anal sphincter defects detected by ultrasound

Abstract

Purpose: The aim of this study was to determine the significance of anal sphincter defects detected by ultrasonography, in a population of fecal incontinent parous females without previous anoperineal surgery.

Methods: From 100 consecutive incontinent patients, 61 females with at least one previous vaginal delivery and no past anoperineal surgery were studied. The severity of fecal incontinence was assessed by the Cleveland Clinic questionnaire score. Lesions of the internal or external anal sphincters, and the radial size of these defects were assessed by ultrasonography. Anal vector manometry was performed to measure anal pressures at rest and during voluntary squeeze, and the anal asymmetry index.

Results: Twenty-three had a normal sphincter (38 percent), and 38 (62 percent) had a defect detected by ultrasonography: 20 isolated defects of the external sphincter and 18 combined defects of the internal and external sphincters. Combined defects were significantly larger. The radial size of the defects was positively correlated with the severity of clinical symptoms. Anal pressure asymmetry index was significantly increased in the group with combined defects compared with the two other groups. An index of 25 percent or greater had a very high (100 percent) negative predictive value for the presence of a defect larger than 90 degrees.

Conclusions: This study confirms the high prevalence of anal sphincter defects detected by ultrasonography in a population of incontinent parous females without previous proctologic surgery. The clinical symptoms are related to the size of these defects. Anal vector manometry may be a useful tool to confirm the relation between echographic anal sphincter lesions and fecal incontinence.