Overview
Definition:
A rectourethral fistula is an abnormal tract connecting the rectum to the urethra, leading to involuntary passage of fecal matter or gas through the urethra, or urinary leakage from the rectum
It represents a complex reconstructive challenge.
Epidemiology:
Incidence is relatively low, with iatrogenic causes (prostatectomy, pelvic radiation, anorectal surgery) being the most common
Traumatic injuries and inflammatory bowel disease (e.g., Crohn's disease) are less frequent etiologies.
Clinical Significance:
Rectourethral fistulas cause significant morbidity, including recurrent urinary tract infections, perineal sepsis, social embarrassment, and profound psychological distress
Accurate diagnosis and timely, appropriate surgical intervention are crucial for patient quality of life and to prevent complications like strictures or chronic sepsis.
Clinical Presentation
Symptoms:
Passage of feces or gas from the urethra
Passage of urine from the rectum
Recurrent urinary tract infections
Perineal pain or discomfort
Incontinence of flatus or feces
Urethral discharge.
Signs:
On digital rectal examination, a palpable tract or induration may be present
Perineal examination may reveal signs of inflammation, induration, or abscess
Urethral and rectal speculum examination might visualize the fistula opening
Vital signs may be normal unless sepsis is present.
Diagnostic Criteria:
Diagnosis is primarily clinical, confirmed by imaging and endoscopic visualization
The presence of characteristic symptoms along with objective evidence of a communication between the rectum and urethra establishes the diagnosis.
Diagnostic Approach
History Taking:
Detailed history of prior pelvic surgery (especially prostatectomy, abdominoperineal resection), radiation therapy, trauma, inflammatory bowel disease, or chronic infections
Onset and progression of symptoms
Previous treatments and their outcomes
Presence of urinary or fecal incontinence.
Physical Examination:
Thorough perineal examination for signs of inflammation, induration, or abscess
Digital rectal examination to assess rectal mucosa, sphincter tone, and palpate for a fistula tract
Urethral meatus inspection
Abdominal examination to rule out associated pathology.
Investigations:
Contrast fistulogram (rectal contrast injection with fluoroscopy to visualize the tract)
CT scan or MRI of the pelvis (excellent for defining fistula tract anatomy, relationship to surrounding structures, and presence of abscesses)
Cystoscopy and proctoscopy/sigmoidoscopy (to identify fistula openings)
Retrograde urethrography (to assess urethral integrity)
Dye tests (e.g., methylene blue instilled in rectum, observed in urethra).
Differential Diagnosis:
Anal fissures
Anal fistulas (non-rectourethral)
Urethral strictures with secondary abscess formation
Colovesical fistulas
Enterocutaneous fistulas
Diverticular disease with abscess formation.
Management
Initial Management:
For acute presentations with sepsis or abscess, immediate drainage of abscesses and broad-spectrum antibiotics are paramount
Diversionary colostomy may be required for severe sepsis or extensive disease.
Medical Management:
Antibiotics to manage associated infections
Bowel rest and nutritional support may be indicated in cases of inflammatory bowel disease
Temporary urinary catheterization to decompress the bladder and prevent contamination.
Surgical Management:
Surgical repair is the definitive treatment
Options include: Direct fistulectomy and primary closure (for small, anterior fistulas)
Transanal repair (e.g., mucosal advancement flaps)
Transperineal repair (e.g., Martius flap for urethral reconstruction, gracilis flap)
Abdominoperineal approach with rectal mobilization and closure, often with a flap interposition
Diversionary colostomy may be necessary, especially for complex or recurrent fistulas
Endoscopic techniques are also evolving.
Supportive Care:
Pain management
Wound care
Nutritional support, particularly if bowel preparation is needed or if a stoma is present
Psychological support for patients dealing with the social and emotional impact of the condition.
Complications
Early Complications:
Wound infection
Rectal or urethral bleeding
Rectal or urethral dehiscence
Anastomotic leak if bowel reconstruction is performed
Urinary retention
New fistula formation.
Late Complications:
Fistula recurrence
Urethral stricture
Erectile dysfunction
Incontinence (urinary or fecal)
Chronic perineal pain
Formation of rectovaginal fistula in females.
Prevention Strategies:
Meticulous surgical technique to avoid injury to the rectum and urethra during pelvic procedures
Careful dissection and hemostasis
Early recognition and management of pelvic abscesses
Appropriate use of diverting ostomies when indicated.
Prognosis
Factors Affecting Prognosis:
Fistula etiology (iatrogenic generally better prognosis than inflammatory)
Size and location of the fistula
Presence of sepsis or significant tissue damage
Previous failed repairs
Patient's overall health status and nutritional status
Sphincter function.
Outcomes:
Successful repair rates vary widely depending on the complexity and etiology, ranging from 50-90%
Recurrence is a significant concern, especially after multiple attempts
Functional outcomes, including continence and sexual function, are critical considerations.
Follow Up:
Regular follow-up is essential to monitor for recurrence, assess functional outcomes (continence, voiding, defecation), and manage any long-term complications such as strictures
Follow-up schedules are typically personalized based on the type of repair and patient recovery.
Key Points
Exam Focus:
Understand the common etiologies and the diagnostic workup for rectourethral fistulas
Differentiate between various surgical repair techniques and their indications
Recognize potential complications and strategies for prevention
High-yield associations with prior pelvic surgery/radiation.
Clinical Pearls:
Always consider a rectourethral fistula in patients with a history of pelvic surgery and new-onset urethral symptoms or gas/fecaluria
Multidisciplinary approach involving urology and colorectal surgery is often beneficial
A good contrast fistulogram or MRI is key for preoperative planning.
Common Mistakes:
Inadequate preoperative imaging leading to incomplete understanding of fistula anatomy
Performing definitive repair without adequate control of sepsis or abscess
Attempting repair without considering diversionary procedures when indicated
Insufficient attention to sphincter preservation during dissection.