You have full access to this open access chapter. Anal sphincter and levator ani LA defects result from trauma, most frequently from obstetrical trauma. Direct repair of the muscle injury occurs in the majority of cases, but some are missed. For old lesions, secondary reconstruction is possible. Clinical assessment shows a decrease in the distance between the anus and the vagina in sphincter defects and perineal asymmetry in LA lesions.
Ultrasound or magnetic resonance imaging are useful to confirm possible perineal damage. The cardinal symptom is anal incontinence. Symptoms are corrected by surgery in two-thirds of the patients. Stems cells and progenitor cells appear as a promising therapy in muscle defects, but whether they should be used in place of surgery or as an adjunct to surgery remains to be defined.
You have full access to this open access chapter, Download chapter PDF. Anal sphincter incontinence ASI results from a functional impairment of one or more of the anatomic components that allow normal continence: the internal anal sphincter IAS , the external anal sphincter EAS , the pelvic floor muscles, the anal cushions that ensure adequate rectal compliance, and the sensory-motor apparatus [ 1 ].
ASI is primarily managed conservatively but sphincter repair surgery is proposed for large defects of either the EAS, IAS, or both after conservative treatment failure [ 2 , 3 ]. An underdiagnosed feature is levator ani LA avulsion, for which we recently proposed a surgical repair technique allowing restoration of LA and puborectalis anatomy [ 4 ]. In patients with ASI, there are at least two mechanisms leading to a modification in pelvic floor structure or function. The episiotomy procedure is also often associated with anal incontinence [ 6 ].
The second mechanism involves the degeneration of the pelvic floor muscles, which appears with aging and particularly after the menopause as the pelvic floor structures are hormone-sensitive [ 5 ]. Direct reconstruction of the muscle injury is the procedure of choice for traumatic tears and obstetrical laceration, as well as for iatrogenic sphincter section.
