Management of Anal Sphincter Disruption / Injury
The Role of Surgical Repair
The anal sphincter does not generally get much attention however, it is a common factor contributing to fecal incontinence. Fecal incontinence, or accidental bowel leakage, (ABL), is a more common issue than most are aware with a reported prevalence in the general population of between 1.4% to 18%. In select groups the incidence of ABL may exceed 50% and because it is such a debilitating condition it is a common reason for transfer to long term care centers. As sphincter disruption from obstetric injury has been recognized in approximately 10% of all vaginal deliveries it should come as no surprise that women are more frequently troubled with ABL. Nearly 20% of women over the age of 45 reported ABL at least once per year and 9.5% reported at least one episode per month.
Fecal continence “control” relies on a complex interaction of rectal sensation, stool consistency, and anal sphincter / pelvic floor musculature and neurologic function. Not surprisingly treatment is challenging and requires an individualized approach focused on the specific issue or issues contributing to each patient’s condition. As new treatment options are now available a complete pelvic floor evaluation typically consisting of endorectal ultrasound, nerve testing, and perhaps defecography should be considered before embarking on a treatment plan. A thorough history and risk assessment is also recommended as clinical success and long term outcomes are likely to vary depending on an individual’s overall health status.
The purpose of this discussion is surgical repair of a demonstrated sphincter defect. It is important to note, however, that even with a documented sphincter injury defect many patients will respond at least in part to non-operative medical management. Additionally, these non-operative treatments can be helpful with post operative care and long term function so many patients will be counseled on these measures to optimize overall success.
Surgical sphincter repair, or “sphincteroplasty”, has been recommended for years and has generally been associated with good to excellent results. In recent years however, the long term success has been questioned and we have clearly seen deterioration in control after five years. It seems natural that if the normally circumferential anatomy of the anal sphincter is disrupted that repair should restore the integrity of the muscle and reconfigure the anatomy of the anal canal. However, given the complex interplay of the muscle strength, rectal sensation, and nerve function, not all patients have favorable results. With more sensitive pelvic floor testing it may be that we can identify those patients best suited for surgical repair. Presently, sphincter repair is generally recommended for otherwise healthy, young individuals who note ABL immediately following or within several years after a sphincter injury. In addition, sphincter repair may be recommended when the anatomy has been significantly distorted or in combination with other problems like rectovaginal fistula. Sphincter repair for individuals with late onset accidental bowel leakage and / or for those over the age of fifty should be carefully counseled as to less optimum success for both short and long term outcomes.