Overview
Definition:
A rectovaginal fistula (RVF) is an abnormal tract connecting the rectum or distal colon to the vagina
This communication allows passage of gas, feces, and/or pus from the rectum into the vagina, or vice versa, leading to significant morbidity.
Epidemiology:
The incidence of RVFs is variable, with obstetric trauma being the most common cause globally, particularly in developing countries due to prolonged labor and lack of skilled birth attendance
Iatrogenic causes from pelvic surgeries (hysterectomy, proctectomy, radiation therapy) are more common in developed nations
Inflammatory bowel disease (Crohn's disease) and malignancy are less frequent etiologies.
Clinical Significance:
RVFs cause profound physical and psychological distress, leading to social isolation, recurrent infections, perineal irritation, and a significant reduction in quality of life
Accurate diagnosis and timely surgical repair are crucial for restoring normal bowel and vaginal function and improving patient well-being
Understanding RVF repair is essential for general surgeons, colorectal surgeons, and gynecologic surgeons preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Passage of flatus or fecal matter from the vagina
Fecal incontinence
Vaginal discharge, often malodorous and purulent
Recurrent urinary tract infections
Perineal irritation and pain
Dyspareunia
Amenorrhea or altered menstrual flow in severe cases.
Signs:
Visualization of the fistula tract opening in the posterior vaginal wall or anterior rectal wall during speculum examination
Palpation of induration or a palpable tract
Evidence of purulent or fecal discharge from the vagina
Perineal skin irritation or signs of infection
Digital rectal examination may reveal abnormalities in the rectovaginal septum.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on a detailed history and physical examination confirming communication between the rectum and vagina
Objective confirmation may be achieved through various investigations, especially for complex or small fistulas, or when multiple etiologies are suspected.
Diagnostic Approach
History Taking:
Detailed history of obstetric events (prolonged labor, tears, episiotomy), previous pelvic surgeries, history of radiation therapy to the pelvis, inflammatory bowel disease symptoms (diarrhea, abdominal pain, weight loss), or malignancy
Inquire about the onset, duration, and character of symptoms
Assess impact on quality of life.
Physical Examination:
A systematic examination includes a general assessment, abdominal examination, and a thorough perineal and pelvic examination
Perineal inspection for skin changes
Digital rectal examination to assess anal sphincter tone, rectal mucosa, and the integrity of the rectovaginal septum
Vaginal speculum examination to visualize the posterior vaginal wall and cervix for signs of fistula opening, discharge, or inflammation.
Investigations:
Fistulography (contrast study via rectal or vaginal catheter) to delineate the tract
MRI pelvis is the gold standard for visualizing complex fistulas, assessing surrounding tissues, and identifying underlying causes like Crohn's disease or abscesses
CT scan may be useful for abscess detection
Anoscopy and flexible sigmoidoscopy/colonoscopy to assess the rectal opening and rule out associated colorectal pathology or malignancy
Urinalysis and urine culture to rule out urinary involvement
Proctoscopy to examine the anal canal and lower rectum.
Differential Diagnosis:
High vaginal fistula (urethrovaginal fistula)
Enterovaginal fistula (from small bowel)
Perianal abscess with secondary vaginal involvement
Chronic vaginitis with purulent discharge
Rectal prolapse with severe mucosal prolapse
Vaginal malignancy extending to the rectum.
Management
Initial Management:
Conservative management may be attempted for very small, asymptomatic or early post-surgical fistulas, focusing on hygiene and topical treatments to promote spontaneous closure
This includes frequent perineal cleansing, use of absorbent pads, and vaginal hygiene measures
Antibiotics may be prescribed for signs of infection or inflammation.
Medical Management:
Antibiotics are primarily used to manage secondary infection and inflammation associated with the fistula
Treatment is typically broad-spectrum and directed at enteric organisms and common vaginal flora
For fistulas associated with inflammatory bowel disease, specific medical therapy (e.g., immunosuppressants, biologics) is crucial and often precedes surgical intervention.
Surgical Management:
Surgical repair is the definitive treatment for most RVFs
The approach depends on the fistula size, location, etiology, and patient's overall health
Indications for Surgery: Persistent symptoms despite conservative management
large or complex fistulas
fistulas not associated with active IBD flare
patient preference for definitive treatment
Surgical Techniques:
1.Fistulotomy/Fistulectomy: For small, low-lying fistulas, the tract is excised and the rectal and vaginal wounds are closed separately or left open to granulate
Often combined with anoplasty or sphincter reconstruction
2.Advancement Flap Techniques: A flap of rectal or vaginal mucosa (and submucosa) is mobilized and advanced to cover the fistula opening
Examples include the endorectal advancement flap and vaginal advancement flap
Suitable for mid-to-high RVFs
3.Gracilistus Myocutaneous Flap Reconstruction: Used for large, complex, or recurrent RVFs, especially those with significant tissue loss or prior radiation
A flap from the thigh provides vascularized tissue to obliterate the defect
4.Seton Placement: A silastic or braided suture is placed through the fistula tract to promote gradual drainage, hygiene, and healing, often as a staged procedure before definitive repair
5.Colostomy/Ileostomy: May be performed as a diverting ostomy in severe or complicated cases, particularly with active IBD or significant perineal contamination, to allow healing before definitive repair
6.Minimally Invasive Techniques: Endoscopic repair, robotic-assisted repair, and laser ablation are emerging options for select cases.
Supportive Care:
Postoperative care involves meticulous wound hygiene to prevent infection and promote healing
Pain management is essential
A high-fiber diet and stool softeners are typically recommended to minimize rectal pressure and irritation
Monitoring for signs of wound dehiscence, infection, or fistula recurrence is critical
Nutritional support may be required for patients with IBD or significant comorbidities.
Complications
Early Complications:
Wound infection or dehiscence
Rectal or vaginal wall necrosis
Anal sphincter injury
Persistent fecal leakage
Pelvic abscess formation
Urinary retention or dysfunction.
Late Complications:
Fistula recurrence
Anal stenosis
Dyspareunia
Chronic perineal pain
Psychological distress and social stigma
Development of secondary malignancy in irradiated tissues
Vaginal vault prolapse after extensive dissection.
Prevention Strategies:
Careful surgical technique with meticulous dissection and secure closure of rectal and vaginal layers
Avoidance of excessive tension on sutures
Appropriate use of diverting ostomies in high-risk patients
Prompt management of postoperative infections
Careful selection of surgical approach based on fistula characteristics and patient factors
Adequate preoperative assessment of IBD activity and radiation damage.
Prognosis
Factors Affecting Prognosis:
Fistula size and location
Etiology (obstetric vs
iatrogenic vs
IBD vs
malignancy)
Presence of comorbidities (IBD, diabetes, immunocompromise)
Previous failed repairs
Radiation therapy history
Sphincter integrity
Skill and experience of the surgeon.
Outcomes:
Successful primary closure rates for simple RVFs can be high (up to 90%) with appropriate techniques
However, complex or recurrent fistulas, especially those related to radiation or severe IBD, have lower success rates and higher recurrence rates
Long-term functional outcomes can be excellent with proper repair, but some patients may experience persistent minor leakage or dyspareunia.
Follow Up:
Regular follow-up is essential to monitor for wound healing, signs of infection, and fistula recurrence
This typically involves clinical examination at 1, 3, 6, and 12 months postoperatively
Further investigations like MRI may be warranted if recurrence is suspected
Patients should be educated on long-term hygiene and potential for minor symptoms.
Key Points
Exam Focus:
Etiologies of RVF (obstetric, iatrogenic, IBD, malignancy)
Diagnostic modalities (MRI pelvis is key for complex fistulas)
Surgical techniques (advancement flaps, gracilis flap)
Indications for diverting ostomy
Factors affecting prognosis and recurrence.
Clinical Pearls:
A high index of suspicion is needed in patients with relevant risk factors
Always perform a thorough digital rectal and vaginal examination
MRI pelvis is crucial for planning complex repairs, especially in irradiated or Crohn's patients
Consider staged management for very complex fistulas
Patient education and support are paramount due to the psychological impact.
Common Mistakes:
Inadequate diagnostic workup, leading to missed underlying pathology or inaccurate mapping of the fistula
Aggressive surgical intervention in the presence of active IBD flare
Insufficient tissue for flap reconstruction in irradiated patients
Overlooking sphincter involvement
Inadequate postoperative wound care, leading to infection and poor healing.