Magnetic Resonance Imaging in Fecal Incontinence

Multimodality imaging of the gastrointestinal manifestations of scleroderma

Scleroderma is a complex multisystem connective tissue disorder. Early visceral disease, such as gastrointestinal (GI) involvement, is associated with significant morbidity and a poorer prognosis. Prompt diagnosis is crucial to allow disease modifying therapies be initiated early in the course of the disease. The primary underlying pathophysiology in the GI tract is dysmotility, muscular atrophy, and fibrosis, and this is reflected in the imaging features. In this paper, we demonstrate the imaging appearances of involvement of the GI tract and describe the use of advanced imaging with magnetic resonance enterography (MRE). A multimodal imaging approach is required to identify both characteristic features of scleroderma and potential complications. Traditional fluoroscopic contrast (barium) studies are still commonly performed for assessment of the oesophagus. More recent advances in cross-sectional imaging allow for thorough three-dimensional assessment of the entire GI tract. MRE is particularly useful for small bowel evaluation while also allowing "pseudodynamic" functional imaging and concomitant assessment of the other abdominal viscera and structures.

Assessing Anorectal Function in Constipation and Fecal Incontinence

Constipation and fecal incontinence are commonly encountered complaints in the gastrointestinal clinic. Assessment of anorectal function includes comprehensive history, rectal examination, and prospective stool diary or electronic App diary that accurately captures bowel symptoms, evaluation of severity, and quality of life of measure. Evaluation of a suspected patient with dyssynergic constipation includes anorectal manometry, balloon expulsion test, and defecography. Investigation of a suspected patient with fecal incontinence includes high-resolution anorectal manometry; anal ultrasound or MRI; and neurophysiology tests, such as translumbosacral anorectal magnetic stimulation or pudendal nerve latency. This article provides an approach to the assessment of anorectal function.

Sacral nerve stimulation for fecal incontinence related to external sphincter atrophy

BACKGROUND

Atrophy of the external anal sphincter, a pathologic muscle volume anomaly associated with fecal incontinence, has been shown to be a negative predictor of the outcome of surgery for defects of the external anal sphincter. It is unclear whether external anal sphincter atrophy also affects the outcome of sacral nerve stimulation for fecal incontinence.

OBJECTIVE

Our aim was to assess the effectiveness of sacral nerve stimulation in patients with fecal incontinence and external anal sphincter atrophy and to determine whether severity of atrophy and concomitant presence of a sphincter defect are negative predictors of outcome.

DESIGN

This was a prospective observational study of treatment outcome.

SETTING

The study was conducted from November 2004 through November 2010 at a regional hospital in Italy.

PATIENTS

Consecutive patients with fecal incontinence and external anal sphincter atrophy were included. By means of MRI, patients were determined to have either moderate (<50%) or severe (≥ 50%) thinning of and/or replacement of sphincter muscle by fat. The concomitant presence of defects of the external anal sphincter was also detected by MRI.

INTERVENTION

All patients underwent sacral nerve stimulation through a staged implantation procedure.

MAIN OUTCOME MEASURES

The main outcome measures were improvement in the Cleveland Clinic Florida Fecal Incontinence Scale (Wexner score), number of episodes of incontinence per week, and the Fecal Incontinence Quality of Life Scale.

RESULTS

A total of 28 patients underwent definitive implantation of the sacral nerve stimulation device. Wexner scores decreased from a median of 16 (range, 10-20) at baseline to 3 (range, 0-8) at 6-month follow-up (p < 0.001). Weekly incontinence episodes decreased from a mean (SD) of 14.7 (12.5) to 0.40 (0.82); p < 0.001. Improvement was significantly related to severity of fecal incontinence (r = 0.86; p < 0.001). Overall quality-of-life scores improved from a mean of 1.8 (0.6) to 3.8 (0.4);p < 0.001. Sacral nerve stimulation was effective in both moderate (n = 16) and severe (n = 12) atrophy and in patients with (n = 8) or without (n = 20) external anal sphincter defects.

LIMITATIONS

The study was limited by its observational nature and relatively small sample size.

CONCLUSIONS

Sacral nerve stimulation can be effective in restoring continence and improving quality of life in patients with fecal incontinence related to atrophy of the external anal sphincter, regardless of the severity of atrophy. Moreover, the presence of EAS atrophy does not influence the success of the outcome of SNS in patients with a sphincter defect. These findings are consistent with the hypothesis that the effects of SNS are not achieved solely by its action on the anal sphincter complex.

Obstetric trauma, pelvic floor injury and fecal incontinence: a population-based case-control study

OBJECTIVES

Current concepts based on referral center data suggest that pelvic floor injury from obstetric trauma is a major risk factor for fecal incontinence (FI) in women. In contrast, a majority of community women only develop FI decades after vaginal delivery, and obstetric events are not independent risk factors for FI. However, obstetric events are imperfect surrogates for anal and pelvic floor injury, which is often clinically occult. Hence, the objectives of this study were to evaluate the relationship between prior obstetric events, pelvic floor injury, and FI among community women.

METHODS

In this nested case-control study of 68 women with FI (cases; mean age 57 years) and 68 age-matched controls from a population-based cohort in Olmsted County, MN, pelvic floor anatomy and motion during voluntary contraction and defecation were assessed by magnetic resonance imaging. Obstetric events and bowel habits were recorded.

RESULTS

By multivariable analysis, internal sphincter injury (cases-28%, controls-6%; odds ratio (OR): 8.8; 95% confidence interval (CI): 2.3-34) and reduced perineal descent during defecation (cases-2.6 ± 0.2 cm, controls-3.1 ± 0.2 cm; OR: 1.7; 95% CI: 1.2-2.4) increased FI risk, but external sphincter injury (cases-25%, controls-4%; P<0.005) was not independently predictive. Puborectalis injury was associated (P<0.05) with impaired anorectal motion during squeeze, but was not independently associated with FI. Grades 3-4 episiotomy (OR: 3.9; 95% CI: 1.4-11) but not other obstetric events increased the risk for pelvic floor injury. Heavy smoking (≥ 20 pack-years) was associated (P=0.052) with external sphincter atrophy.

CONCLUSIONS

State-of-the-art imaging techniques reveal pelvic floor injury or abnormal anorectal motion in a minority of community women with FI. Internal sphincter injury and reduced perineal descent during defecation are independent risk factors for FI. In addition to grades 3-4 episiotomy, smoking may be a potentially preventable, risk factor for pelvic floor injury.