An Active Duty Woman with Anal Incontinence after Vaginal Delivery: An Elusive Diagnosis

Military Medicine, Dec 2004 by O'Boyle, Amy L, O'Boyle, John D, Place, Ronald J

Anal sphincter injury as a result of birth trauma is the leading cause of fecal incontinence in women presenting to surgical clinics. A 36-year-old active duty woman was referred to the Urogynecology Clinic at Madigan Army Medical Center for evaluation of a deficient perineal body. She reluctantly reported a 12-year history of anal incontinence since the birth of her first child, predating her entry into the naval service. Examination revealed defects of the perineum and anal sphincter resembling a cloacal deformity. Uncomplicated overlapping anal sphincteroplasty and perineorrhaphy were performed, restoring perineal anatomy and continence. Anal incontinence and other anatomic defects attributable to lacerations sustained at childbirth may go undetected during routine screening examinations. Interview and examination techniques should be emphasized in primary care settings.

Introduction

Despite improvements in modern obstetric care, injury to the anal sphincter as a result of vaginal birth remains a significant problem with potentially devastating consequences for affected women. Anal sphincter injuries and their sequelae are responsible for an increasing number of women presenting for surgical evaluation and have been cited in a growing number of physician liability cases. Trauma to the anal sphincter as a result of delivery is the leading cause of fecal incontinence.1,2 Fortunately, effective treatment may be available in many cases. Thus, it is imperative for providers of women's health care to be aware of this condition.2

There is a spectrum of perineum and anal sphincter injuries that may result from childbirth. These range from perineal lacerations with occult sphincter injuries to complete disruptions of the perineal body, resulting in a common opening between the vagina and rectum, resembling a cloacal deformity.3,4 The latter type of injury is thought to be rare, with a reported incidence of 0.003% of all vaginal deliveries.5 These defects likely occur after disruption of the anal sphincter and perineal body at the time of delivery, followed by failure of the primary repair because of infection, hematoma, suture breakage, or straining at defecation.5 Although the description is quite dramatic, these defects may have subtle findings that may be overlooked during a routine pelvic examination. If the patient does not report her symptoms, which almost always includes anal incontinence of gas and stool, she may suffer in silence believing that this is normal.6 We present the evaluation and management of an active duty sailor that suffered for 12 years with a cloaca-like perineal defect after her first delivery, which occurred before her entry into the military.

Case Report

A 36-year-old gravida 2 para 2 active duty woman was referred to the Urogynecology Clinic at Madigan Army Medical Center by a staff gynecologist in a nearby military medical facility for "relaxation of the perineal body and anal sphincter." When questioned regarding symptoms, she reported a 12-year history of inability to control flatus and liquid stool since the birth of her first child. She wore a pad for protection at all times, and experienced soilage on a daily basis. After a bowel movement, she usually returned to the restroom several times because of soilage. She also had chronic vulvar irritation that had been attributed to and treated on numerous occasions as candidiasis. She reported abstinence from vaginal intercourse because of discomfort and embarrassment. Details of her first birth were not available, but her description was consistent with a fourth-degree laceration. She denied any history of wound breakdown, but states she was told that this problem was secondary to having intercourse "too soon." Several years later, she had undergone Cesarean delivery for breech presentation.

Clinical examination revealed complete absence of the perineal body and the distal rectovaginal septum. Inspection of the perineum and perianal region revealed skin changes consistent with chronic dermatitis and perianal skin dimpling at 3 and 9 o'clock, a classic finding in women with retracted external anal sphincter muscles.7 Digital rectal examination confirmed the absence of the perineal body and anal sphincter. Manual assessment of the puborectalis muscles, those muscles primarily responsible for control of solid stool, revealed hypertrophy and excellent tone, consistent with compensation for a defective sphincter complex. Further evaluation included anal manometry, pudendal nerve'terminal motor latency testing, and anal endosonography. Results of these studies were consistent with anterior disruption of the external anal sphincter without evidence of pudendal neuropathy. She was diagnosed with a type III rectovaginal defect. Classification of anatomic defects of the rectovaginal septum secondary to obstetric and/or surgical trauma has been described by Rosenshein et al.8 and is depicted in Table I. She underwent an uncomplicated overlapping anal sphincteroplasty and perineorrhaphy after a standard antibiotic and mechanical bowel preparation.3 Her postoperative recovery was complicated by a separation of the perineal skin that was allowed to heal by secondary intention; the repaired anal sphincter was intact. Approximately 1 year after her initial presentation, she reported continence of flatus and liquid stool. On digital rectal examination, she had good anal sphincter tone and a 1.5-cm perineal body measured by palpation.