Overview
Definition:
A rectovaginal fistula (RVF) is an abnormal communication between the rectum and the vagina
Repair with a Martius flap involves using a vascularized flap of subcutaneous tissue from the labia majora to cover and close the fistula tract.
Epidemiology:
RVFs are uncommon, with incidence varying based on etiology
They can result from obstetric trauma (especially prolonged labor, instrumental delivery), surgical complications (e.g., hysterectomy, anal sphincteroplasty), inflammatory bowel disease (Crohn's), radiation therapy, or malignancy
Incidence is higher in resource-limited settings with higher rates of prolonged labor and obstetric injury.
Clinical Significance:
RVFs significantly impact a patient's quality of life, causing fecal incontinence, malodor, recurrent infections, and psychological distress
Effective surgical management is crucial for restoring continence, improving hygiene, and enabling patients to return to normal social functioning
Understanding reconstructive techniques like the Martius flap is vital for surgical residents preparing for DNB and NEET SS exams.
Indications And Contraindications
Indications:
Symptomatic RVF unresponsive to conservative management
Fistulas greater than 1-2 cm in diameter
Post-surgical or post-radiation fistulas
Complex fistulas requiring robust tissue coverage.
Contraindications:
Active infection or inflammation at the site
Severe malnutrition or immunocompromise
Uncontrolled systemic disease
Patient refusal or inability to comply with postoperative care
Inadequate labial tissue for flap mobilization.
Preoperative Preparation
History And Examination:
Detailed history of onset, etiology, previous treatments, and symptoms
Thorough perineal and pelvic examination to assess fistula size, location, and surrounding tissue health
Assess for concurrent obstetric or anal sphincter injuries.
Investigations:
Fistulography (if available) to delineate tract
Rectovaginal examination with speculum and proctoscope
Methylene blue or other dye test to confirm communication
Colonoscopy to rule out underlying inflammatory bowel disease or malignancy
Pelvic MRI for detailed anatomical assessment and extent of damage.
Patient Counseling:
Discuss surgical options, risks, benefits, and expected outcomes
Explain the Martius flap procedure, including donor site and potential complications
Emphasize postoperative care requirements, including wound care and bowel management.
Bowel Preparation:
Standard bowel preparation with clear liquids and laxatives in the days preceding surgery
Prophylactic antibiotics (e.g., ceftriaxone and metronidazole) administered intravenously
Stool softeners and a low-residue diet postoperatively.
Martius Flap Procedure
Anesthesia And Positioning:
General anesthesia is typically used
The patient is placed in the lithotomy position to provide optimal surgical access to the perineum and vagina.
Fistula Excision And Mobilization:
The fistula tract is carefully dissected and excised from both the vaginal and rectal aspects
The edges of the rectal defect may be debrided
Care is taken to avoid further injury to the sphincter complex.
Martius Flap Harvest:
A curved incision is made over the labia majora to harvest a full-thickness flap of subcutaneous fat and skin
The flap is based on the labial artery and vein
The pedicle is carefully mobilized to allow rotation and closure of the fistula defect.
Flap Insertion And Closure:
The harvested Martius flap is tunneled through the perineal tissues to the fistula site
The flap is meticulously sutured to cover the rectal defect, providing a well-vascularized barrier
The vaginal and rectal mucosa are then primarily closed over the flap.
Donor Site Closure:
The donor site on the labium majus is closed primarily, ensuring good hemostasis and preventing dead space
Drains may be placed if necessary
The perineal wound is closed in layers.
Postoperative Care And Management
Wound Care:
Regular dressing changes with antiseptic solutions
Monitor for signs of infection or flap ischemia
Sitz baths can be beneficial for perineal hygiene.
Pain Management:
Analgesics, including opioids if necessary, for postoperative pain
Muscle relaxants may be used to reduce sphincter spasm.
Bowel Management:
Initiate a low-residue diet and stool softeners to minimize bowel movements and stool bulk
Avoid straining
Gradual progression to a regular diet as tolerated.
Monitoring:
Close observation for signs of flap viability, wound dehiscence, infection, or recurrence of the fistula
Monitor urine output and bowel function
Antibiotic therapy is continued postoperatively.
Complications
Early Complications:
Flap necrosis or partial loss
Wound infection
Hematoma or seroma formation
Dehiscence of the rectal or vaginal closure
Urinary retention
Postoperative bleeding.
Late Complications:
Fistula recurrence
Stenosis of the vagina or rectum
Chronic perineal pain
Vulvar lymphedema
Scarring and cosmetic issues at the donor site.
Prevention Strategies:
Meticulous surgical technique to ensure adequate flap vascularity and tension-free closure
Strict adherence to postoperative bowel management protocols
Prompt recognition and management of early signs of complications
Careful patient selection and pre-operative optimization.
Prognosis And Follow Up
Factors Affecting Prognosis:
Fistula etiology (radiation-induced fistulas have poorer outcomes)
Fistula size and complexity
Patient's overall health status
Surgeon's experience
Adherence to postoperative care.
Outcomes:
Successful closure rates for Martius flap repair are generally high, often exceeding 80-90% for carefully selected cases
However, recurrence is possible, particularly in complex or radiation-induced fistulas
Long-term functional outcomes related to continence depend on the integrity of the sphincter mechanism.
Follow Up:
Regular follow-up appointments are scheduled at 1 week, 1 month, 3 months, and 6 months post-surgery
This includes clinical examination to assess wound healing, flap integrity, and functional status
Repeat imaging or examination may be performed if recurrence is suspected.
Key Points
Exam Focus:
Martius flap is a well-vascularized pedicled flap primarily for RVF repair
It provides excellent bulk and coverage for complex or large defects
Donor site is the labia majora
Key to success is meticulous flap harvest and secure closure.
Clinical Pearls:
In complex cases, consider staged repair or diversion
Always assess sphincter function preoperatively
Ensure adequate pedicle length for tension-free placement
Postoperative bowel management is paramount to reduce stress on the repair.
Common Mistakes:
Insufficient flap mobilization leading to tension
Inadequate excision of the fistula tract
Failure to address underlying causes (e.g., IBD)
Poor postoperative bowel care leading to dehiscence or strain on the repair.