Which method is best for imaging of anal sphincter defects?

Long-term function and morphology of the anal sphincters and the pelvic floor after primary repair of obstetric anal sphincter injury

AIM

More than 50% of women experience deteriorating continence over time following primary repair of obstetric anal sphincter injuries. The objectives of this study were to assess the function and morphology of the anal sphincters and pelvic floor in women with long-term faecal incontinence after sphincter repair (primary end-point) and to evaluate their correlation with severity of incontinence (secondary end-point).

METHOD

The participants in this prospective study were recruited from a cohort of all women who sustained third or fourth degree obstetric sphincter injury reconstruction (cases) from January 1976 to November 1991. The women who delivered immediately before and after each case, without sustaining obstetric damage, were included as controls. Cases and controls were stratified into three categories: (i) continent; (ii) minor incontinence; and (iii) severe incontinence. The function and morphology of the anal sphincters and pelvic floor were evaluated by MRI, three-dimensional endoanal ultrasonography and anorectal physiology tests.

RESULTS

Fifty-nine women (29 cases/30 controls; mean age 51/53 years; mean follow-up 23.7/24.1 years, respectively) were assessed. Morphologically, cases had a significantly shorter anterior external anal sphincter length compared with controls when evaluated by three-dimensional endoanal ultrasonography (8.6 vs 10.2 mm; P = 0.03). Functionally, cases with severe incontinence had a significantly shorter anterior sphincter length compared with cases with minor incontinence (7.7 vs 10.4 mm; P = 0.04). No correlation could be found between anal pressures and severity of incontinence in the case group.

CONCLUSIONS

Cases had a significantly shorter anterior external anal sphincter length. Functionally, anterior sphincter length correlated with increased severity of incontinence.

Usefulness of 3D transperineal ultrasound in severe stenosis of the anal canal: preliminary experience in four cases

Background

Organic or functional anal canal stenoses are uncommon conditions that occur in the majority of cases as a consequence of anal diseases. A proper assessment is fundamental for decision making; however, proctological examination and endoanal ultrasound are often unfeasible or very difficult to perform even under local or general anesthesia. We therefore began to use 3D transperineal ultrasound to assess patients. The aim of this study was to compare the results of evacuation proctography and 3D transperineal ultrasound in patients with severe anal canal stenosis.

Methods

Four consecutive patients with high-grade anal canal stenosis were evaluated using both proctography and 3D transperineal ultrasound with a micro-convex transducer between March and June 2011.

Results

In all cases, 3D transperineal ultrasound provided detailed information on the length and level of stenosis and on the integrity of the anal sphincters.

Conclusions

Our preliminary experience suggests that 3D transperineal ultrasound makes it possible to plan optimal surgical treatment.