Advanced Anal Fistula Repair Focused on Closing the Internal Opening While Preserving Sphincter Function
Advancement Flap, also known as a Mucosal Advancement Flap or endorectal advancement flap, is a sphincter-preserving surgical technique used to treat selected anal fistulas, particularly when dividing the anal sphincter would create an unacceptable risk to continence. In Brazil, Dr. Kaiser Jr. offers advancement flap surgery as part of an individualized approach to anal fistula treatment, selecting the technique according to fistula anatomy, complexity, previous surgery, and sphincter involvement.
Rather than opening the fistula through the sphincter muscle, the procedure focuses on treating the fistula tract and covering its internal opening with healthy rectal tissue. This approach can be particularly valuable for complex or recurrent fistulas where preservation of continence is an important priority. Dr. Kaiser Jr.’s website reports a success range of approximately 55% to 75% for advancement flap treatment and notes that the technique may also be combined with other fistula procedures when clinically appropriate.
🩺 What Is Advancement Flap (Mucosal Flap) for Anal Fistula?
An Advancement Flap is a surgical procedure used to close the internal opening of an anal fistula without cutting the anal sphincter muscles. An anal fistula is an abnormal channel between the anal canal and the skin around the anus, often causing drainage, pain, swelling, and recurrent abscesses. Complex fistulas may involve a large portion of the sphincter, making careful treatment planning essential. During the procedure, the surgeon identifies the fistula tract, cleans it, and creates a small rectal mucosal flap.
This flap is then advanced to cover and seal the internal opening, placing healthy tissue over the fistula’s origin.
The goal is to treat the fistula while preserving sphincter function, making it a sphincter-sparing option often used in complex cases or when fistulotomy would risk continence. However, recurrence can still occur.
Treatment is always individualized based on fistula anatomy, previous surgeries, inflammation, tissue quality, and patient factors. In some cases, the advancement flap may be combined with other techniques.
🩺 Types of Advancement Flap Procedures
- Mucosal Advancement Flap – Uses mobilized rectal mucosa and supporting tissue to cover the internal fistula opening after preparation of the affected area.
- Advancement Flap With Additional Fistula Treatment – In selected complex or recurrent cases, the flap may form part of a combined treatment strategy. Dr. Kaiser Jr. notes that mucosal advancement flap surgery can be combined with other techniques when clinically appropriate.
🩺 Who Is a Good Candidate?
Advancement Flap surgery may be suitable for patients with anal fistulas where closing the internal opening while preserving sphincter function is an important treatment objective. It is frequently considered when a straightforward fistulotomy could involve too much sphincter muscle or create a greater risk of continence problems.
✔️ Patients with selected complex anal fistulas
✔️ Individuals with fistulas involving a clinically significant portion of the anal sphincter
✔️ Patients for whom sphincter preservation is an important treatment priority
✔️ Individuals with recurrent anal fistulas after previous treatment
✔️ Patients whose fistula anatomy is not well suited to a simple fistulotomy
✔️ Individuals with an identifiable internal fistula opening that can be surgically addressed
📝 Consultation & Preparation
Careful evaluation is essential before Advancement Flap surgery because anal fistulas differ in their relationship to the sphincter muscles. Treatment is based on full fistula anatomy, not symptoms alone, and Dr. Kaiser Jr. individualizes care according to classification, complexity, and prior surgical history.
✔️ Detailed review of anal fistula symptoms and duration
✔️ Assessment of previous abscesses, drainage procedures, or fistula surgeries
✔️ Physical and anorectal examination when clinically appropriate
✔️ Identification of the internal and external fistula openings
✔️ Evaluation of the relationship between the tract and anal sphincter muscles
✔️ Review of medical conditions, medications, allergies, and previous operations
✔️ Evaluation for active infection or abscess before definitive fistula repair
🩺 Recovery & Aftercare
Recovery after Advancement Flap surgery varies depending on fistula complexity, prior procedures, and overall health. Because the procedure preserves the sphincter, care focuses on protecting the repair, easing bowel movements, and monitoring healing. Mild pain, drainage, or swelling may occur early, so patients should follow instructions while the flap heals over the internal opening.
✔️ Use prescribed pain medication according to medical instructions
✔️ Keep the anal area clean without aggressive rubbing or irritation
✔️ Use warm sitz baths if recommended by the surgical team
✔️ Maintain adequate hydration during recovery
✔️ Follow dietary and fiber recommendations to support comfortable bowel movements
✔️ Avoid constipation and excessive straining
✔️ Take stool-softening medication when prescribed
✔️ Avoid strenuous exercise and heavy lifting until medically cleared
✔️ Monitor for increasing pain, fever, swelling, heavy bleeding, or worsening drainage
✔️ Attend scheduled postoperative examinations to evaluate flap healing
🌍 Why Choose Dr. Kaiser Jr. and His Hospital Network in Brazil for Advancement Flap Surgery?
Treatment of complex anal fistulas requires precise mapping, sphincter knowledge, review of prior failures, and selection of a sphincter-preserving strategy. Dr. Roberto Luiz Kaiser Júnior is an experienced surgeon and proctologist with over 30 years of expertise, trained at Cleveland Clinic Florida and Université Louis Pasteur in Strasbourg. He performs surgery in leading hospitals in São Paulo and São José do Rio Preto, including Hospital Israelita Albert Einstein, Hospital São Luiz units, Kaiser Hospital, and Hospital Beneficência Portuguesa, with the facility chosen based on each patient’s needs and treatment plan.
✔️ More than 30 years of surgical experience reported by Dr. Kaiser Jr.’s practice
✔️ Specialist background in general surgery and coloproctology
✔️ Fellowship experience at Cleveland Clinic Florida
✔️ Clinical fellowship training at Université Louis Pasteur in Strasbourg
✔️ Experience with multiple anal fistula techniques rather than a single treatment approach
✔️ Individualized technique selection according to fistula classification and complexity
✔️ Availability of sphincter-preserving procedures including advancement flap, LIFT, VAAFT, and FiLaC
