Hypothesis / aims of study
Describe the demographic, clinical, ultrasonographic and manometric characteristics of patients with fecal incontinence and anal sphincter disruption, treated at the Anorectal Physiology Unit of our Coloproctology Service.
Evaluate the clinical degree of fecal incontinence with the Wexner score.
Assess the degree of anal sphincter involvement using the Starck ultrasonography severity index.
Study design, materials and methods
It is a retrospective study including 37 patients with fecal incontinence and a history of anal sphincterdisruption. The demographic, clinical, ultrasonographic and manometric data of each one of the patients with anal sphincter disruption and fecal incontinence were collected. Wexner clinical scale and the Starck ultrasonography severity index were used to evaluate the degree of fecal incontinence and anal sphincter disruption, respectively. Statistical analysis, was performed with statistical package SPSS version 24.0. Descriptive statistics were used for the presentation of each of the variables. The quantitative variables were expressed as means and standard deviation, the categorical variables were presented in frequencies and percentages
Interpretation of results
The structural lesions of the anal sphincter have been recognized for many years as one of the main etiologies for fecal incontinence, either for the presence of obstetric injuries in women or by history of anorectal surgery in both sexes.
The relationship between the structural lesions of the anal sphincter complex and the functional repercussion measured by anorectal manometry is controversial. In our experience, the length measurement of the anal canal at rest was 1.63 ± 0.38 cm. The mean resting pressure was 32.44 ± 19.2 mmHg and the mean contraction pressure was 59.75 ± 30.69 mmHg, the latter with values below the established normal. It should be noted that, Voyvodic et al1 could observe that there were statistically significant differences between the basal and voluntary contraction pressure only in patients who had a severe lesion of the sphincter muscles, or, conversely, in those who did not present with disruptions. Bordeianou et al.2 recently compared the manometric pressures and degrees of involvement in 2 of the 3 space axes (longitudinal and transverse) of both the EAI and the EAE, and concluded that, as the circumferential degrees of sphincters disruption increases, pressures tend to decrease.
In addition to evaluating resting and contraction pressures, we evaluated rectal sensitivity with rectal compliance tests, observing the mean of the first rectal sensation, first defecation desire and intense defecatory desire at 41.52 ± 22.33 cc, 70.06 ± 22.67 cc and 125.38 ± 38.32, respectively. These latest data have not been reported in previous studies, but we believe they should be taken into consideration since sphincter disruption could predispose developing rectal sensitivity dysfunction.
Only a few studies exist utilizing Starcks scoring system for sphincter disruption. This score, which uses 3 axes of space for evaluation (depth, length and degrees of circumference) seems like a valuable instrument for categorize such lesions.
It is estimated that at least 18 million adults in the US suffer from fecal incontinence, approaching 50% in institutionalized patients, as occurs in nursing homes. Fecal incontinence (FI) significantly increases morbidity and decreases quality of life. Despite not being life-threatening, patients consider it traumatic and often disabling.
FI with anal sphincter disruption is a frequent condition with predominance in the female gender and may be aggravated by different associated factors. Its diagnosis and treatment is very complex due to the clinical heterogeneity of the patients; it requires an integral evaluation considering clinical, imaging and functional aspects in order to assess the severity and homogenize its diagnosis and treatment.
There are several diagnostic studies that can be performed to evaluate the underlying cause of fecal incontinence, being the endoanal ultrasound the standard diagnostic tool for determining the presence of a disruption in the anal sphincter. It is a simple test that should be used in women who have FI and a history of previous vaginal delivery or anorectal surgery.
High resolution anorectal manometry is useful in the diagnosis of FI and can evaluate the primary anatomical components that ensure continence related to muscle tone and innervation. It can also assess RAIR, rectal sensation, and rectal compliance; the latter evaluates volume changes and can provide information about rectal accommodation. Manometry readings, which should demonstrate relaxation of the internal anal sphincter for a normal response, are usually hyper or hyposensitive for patients with fecal incontinence.