Fistulae: Gastrointestinal and Urinary Tract

Introduction

• Description: A fistula is an abnormal communication between two cavities or organs. In gynecology, this usually refers to a communication between the gastrointestinal or urinary tract and the genital tract. Connections directly to the skin are not discussed here.

• Prevalence: Gastrointestinal fistulae are uncommon; urinary tract fistulae are estimated to occur in 1/200 abdominal hysterectomies.

• Predominant Age: Reproductive age and older.

• Genetics: No genetic pattern.

Etiology and Pathogenesis

• Causes: Fistulae between the gastrointestinal tract and vagina may be precipitated by the same injuries that cause genitourinary fistulae; the most common are obstetric injuries and complications of episiotomies or perineal obstetric tears (lower one-third of the vagina). Fistulae may also follow hysterectomy or enterocele repair (upper one-third of vagina). Inflammatory bowel disease or pelvic radiation therapy may hasten or precipitate fistula formation. Urinary tract fistulae may result from surgical or obstetric trauma, irradiation, or malignancy, although the most common cause by far is unrecognized surgical trauma. Approximately 75% of urinary tract fistulae occur after abdominal hysterectomy (0.1%–0.5% following simple hysterectomy; 10% following radical hysterectomy). Signs of a urinary fistula (watery discharge) usually occur from 5–30 days after surgery (average, 8–12 days), although they may be present in the immediate postoperative period.

• Risk Factors: Gastrointestinal fistulae—obstetric tears, puncture wounds, inflammatory bowel disease, diverticular disease, improper pessary use, intraabdominal surgery, carcinoma, radiation therapy, perirectal abscess. Although Crohn disease, lymphogranuloma venereum, or tuberculosis are recognized risk factors, these are uncommon. Urinary tract fistulae—surgery or radiation treatment. Urinary tract fistulae are most common after uncomplicated hysterectomy, although pelvic adhesive disease, endometriosis, or pelvic tumors increase the individual risk.

Signs and Symptoms

Diagnostic Approach