How common is a uterine‑abdominal fistula after hysterectomy?

Uterine-Abdominal Fistula After Hysterectomy

A uterine-abdominal fistula after hysterectomy is extremely rare, occurring in approximately 0.1-4% of cases, with the most common types being intestinogenital (47%) and urogenital (26%) fistulas rather than direct uterine-abdominal connections. 1, 2

Clarification of Terminology

• After hysterectomy, the uterus is removed, so a true "uterine-abdominal" fistula cannot exist—the question likely refers to pelvic organ fistulas connecting the vaginal cuff, bladder, or bowel to the peritoneal cavity 1, 2
• The most relevant post-hysterectomy fistula is a peritoneovaginal fistula (vaginal cuff to peritoneal cavity), which is rare but documented 3

Overall Incidence and Risk

• Pelvic organ fistula surgery occurs at a rate of 23.8 per 100,000 person-years after hysterectomy, compared to 6.3 per 100,000 in women without hysterectomy—representing a four-fold increased risk 2
• The number needed to harm is 5,700, meaning one fistula occurs for every 5,700 hysterectomies performed 2
• Risk is highest in the first year post-surgery, with a more than 20-fold increased hazard ratio (HR 21.2,95% CI 14.9-30.2) compared to baseline 2

Fistula Types and Distribution

• Intestinogenital fistulas are most common (47%), typically connecting bowel to vaginal cuff 2
• Urogenital fistulas account for 26%, most commonly vesicovaginal (bladder to vagina) 1, 4, 5, 2
• Peritoneovaginal fistulas (vaginal cuff to peritoneal cavity) are documented but represent a small minority of cases 3

Risk Factors by Surgical Approach

• Laparoscopic hysterectomy carries the highest fistula risk at 95.9 per 100,000 person-years 2
• Total abdominal hysterectomy has intermediate risk 2
• Subtotal abdominal hysterectomy has the lowest risk at 13.7 per 100,000 person-years 2
• Vaginal hysterectomy also carries fistula risk, though specific rates vary 1, 4

Additional Risk Factors

• Increasing age is associated with higher fistula rates 2
• Smoking, diverticulitis, and pelvic adhesions increase risk 1
• Radical hysterectomy (for malignancy) has higher incidence (up to 4%) compared to benign indications (0.1-2%) 1

Pathophysiology

• Iatrogenic injury to urinary tract or bowel during surgery is the primary mechanism 1
• Postoperative infections contribute to fistula formation 1
• Tissue ischemia and necrosis at suture lines can lead to breakdown and fistula development 4, 5

Clinical Presentation

• Peritoneovaginal fistulas present with pelvic pain and vaginal discharge 3
• Vesicovaginal fistulas present with continuous urinary leakage through the vagina 4, 5
• Intestinogenital fistulas present with passage of stool or gas through the vagina 2
• Most fistulas are located at the vaginal cuff, the site of uterine removal 5

Critical Pitfalls

• The term "uterine-abdominal fistula" is anatomically impossible after hysterectomy since the uterus has been removed—clarify whether the patient has vaginal discharge, urinary leakage, or passage of bowel contents to determine fistula type 3, 4, 5
• Do not delay evaluation if fistula is suspected—most occur within the first year and early diagnosis improves outcomes 2
• Laparoscopic approach carries highest risk, so maintain heightened vigilance in this population 2