Cutting-edge laser treatment for anal fistulas, sphincter-preserving, day-care procedure with minimal pain and low recurrence rates.
Anal Fistula at a Glance
An anal fistula is an abnormal tunnel that forms between the inside of the anal canal and the skin around the anus. It almost always develops after an anal abscess, a pocket of infection in the glands just inside the anal canal. When the abscess drains (either spontaneously or surgically), a persistent channel sometimes remains, creating the fistula. The tract stays open because it is constantly contaminated by bowel contents passing through the anal canal.
Fistulas cause recurrent discharge of pus or blood-stained fluid onto the surrounding skin, associated with discomfort, itching and periodic flare-ups of infection. They never heal on their own. Surgery is always required to eliminate the tract permanently.
Traditional fistula surgery (fistulotomy) cuts through the sphincter muscle overlying the tract. For simple, low fistulas, this is safe. For complex or high fistulas that pass through a significant portion of the sphincter, cutting carries a real risk of bowel control problems. FiLaC (Fistula-track Laser Closure) bypasses this risk entirely by ablating the tract from within using a laser probe, leaving the sphincter completely untouched. This makes it the preferred approach for complex and recurrent fistulas.
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Book Consultation 📞 +91 93533 16175The procedure takes 30 to 45 minutes under spinal or general anaesthesia. The sphincter muscle is not cut at any point during the operation.
Spinal or general anaesthesia is administered. The patient is positioned to give complete access to the anal area. The external skin opening of the fistula is identified and marked.
A probe is passed through the fistula tract to map its course and confirm the internal opening in the anal canal. The depth and relationship to the sphincter muscle is carefully assessed.
A radially emitting laser probe (FiLaC system) is introduced into the fistula tract through the external opening. The probe delivers laser energy in a 360-degree pattern as it is slowly withdrawn along the tract.
The laser energy ablates and destroys the fistula tract lining from within, causing it to collapse and seal. No sphincter muscle is cut or divided at any stage. Secondary tracts are also treated if present.
The internal opening is closed with a small suture. The external opening is curetted clean. A simple dressing is applied. Most patients go home within 4 to 6 hours of the procedure.
Home the same day. Mild soreness at the external opening is expected. Take prescribed analgesics and stool softeners. Keep the area clean with sitz baths twice daily.
Return to desk work and light activity. Some mild discharge from the external opening for the first week is normal, the tract is healing from within. Keep the area clean and dry.
The external opening gradually closes. Discharge decreases significantly. Avoid strenuous physical activity and heavy lifting. Continue sitz baths and high-fibre diet.
Complete closure of the tract in the majority of patients. A follow-up examination confirms healing. If any residual tract persists, a further laser session may be planned.
Fistulas are classified by how the tract relates to the two sphincter muscles that control continence. This classification, described by Parks, determines what can and cannot be done safely.
| Type | Path of the tract | Treatment implication |
|---|---|---|
| Intersphincteric | Runs between the internal and external sphincters and out to the skin. The most common type. | Often suitable for laying open, as little or no external sphincter is involved. |
| Transsphincteric | Crosses through both the internal and external sphincters into the ischioanal fossa. | Laying open risks continence. Sphincter preserving techniques are preferred. |
| Suprasphincteric | Passes upward above the puborectalis muscle before descending to the skin. | Complex. Requires sphincter preserving management, often staged. |
| Extrasphincteric | Runs from the rectum, outside the sphincter complex entirely, to the skin. | Uncommon. Usually indicates another underlying cause that must be identified. |
Simple compared with complex. In practice fistulas are also described as simple or complex. A simple fistula is low, single and involves minimal sphincter. A complex fistula involves a substantial amount of sphincter, has multiple tracts, is recurrent, is anterior in a woman, or occurs alongside Crohn's disease, radiotherapy or poor pre-existing continence. Complex fistulas need a more cautious, often staged approach.
Why the classification matters so much. There is a genuine trade-off in fistula surgery between the chance of cure and the preservation of continence. The most reliable way to cure a fistula is to lay the tract open, but doing so through significant sphincter muscle causes incontinence. Every modern sphincter preserving technique, including FiLaC, exists to navigate that trade-off.
Around nine in ten fistulas arise from infection of the small glands that sit between the sphincter muscles and open into the anal canal. When such a gland becomes blocked and infected, pus tracks outward to form a perianal abscess. When that abscess drains, whether spontaneously or surgically, a tract may persist between the gland and the skin. That is the fistula.
The single commonest antecedent. A proportion of drained abscesses go on to leave a fistula.
Inflammatory bowel disease can produce multiple, complex and recurrent fistulas that need a combined medical and surgical approach.
An important consideration in India. Tuberculous fistulas need antitubercular treatment alongside surgery.
Impairs healing and increases susceptibility to perianal sepsis.
Including obstetric injury, which can create a tract or complicate treatment.
A chronic skin condition that can produce perianal tracts resembling fistulas.
Impairs tissue healing and can lead to fistula formation.
Impairs healing and is associated with poorer outcomes after fistula surgery.
Identifying the underlying cause is not academic. A tuberculous or Crohn's related fistula treated as if it were a simple cryptoglandular tract will recur, because the disease driving it has not been addressed.
Assessment answers three questions: where is the internal opening, how much sphincter does the tract cross, and is there an underlying disease.
History and examination. The typical story is of recurrent perianal discharge of pus or blood, often with intermittent painful swelling that settles when it bursts. An external opening is usually visible as a small punctum near the anus, sometimes with granulation tissue around it. A cord-like tract may be felt.
MRI of the pelvis. This is the standard investigation for anything other than an obviously simple, low fistula. MRI maps the tract and any secondary extensions or collections in relation to the sphincter complex, without discomfort or radiation. Skipping this step in a complex fistula is one of the main reasons surgery fails, because an unrecognised side branch is left behind.
Endoanal ultrasound. An alternative or complementary method of assessing the tract and the sphincters, useful where MRI is not available or is contraindicated.
Examination under anaesthesia. Gentle probing of the tract, sometimes with dye, defines the anatomy directly. This is often combined with the definitive procedure but may be done as a separate staging step in complex disease.
Investigating the underlying cause. Where there are multiple tracts, recurrent disease, diarrhoea, weight loss or a suggestive history, colonoscopy and biopsy are arranged to look for Crohn's disease, and tissue may be sent for tuberculosis testing.
Laser closure is particularly useful where preserving the sphincter is the priority, which is most transsphincteric and complex fistulas. Suitability is decided after the anatomy has been mapped.
| Usually suitable | Needs discussion first |
|---|---|
| Transsphincteric fistula where laying open would risk continence | Very short, superficial tracts, which may be better simply laid open |
| Recurrent fistula after previous surgery | An undrained abscess or collection, which must be drained first |
| A patient in whom continence is already marginal | Multiple complex branching tracts, which often need a staged approach |
| A single, well-defined tract mapped on MRI | Active Crohn's disease, which needs medical treatment alongside surgery |
| A wish to avoid an open wound and prolonged dressing changes | Suspected tuberculosis, which needs antitubercular therapy |
A loose draining seton is often placed first. This is a soft thread left through the tract for several weeks to let inflammation settle and the tract mature. It is not a failure or a delay tactic. Operating on an acutely inflamed tract gives worse results, and a settled tract closes more reliably.
Most people continue normal activity until the day of surgery.
Fistula surgery deserves a particularly frank discussion, because recurrence is a genuine possibility with every technique and no surgeon can promise otherwise. Sphincter preserving methods such as FiLaC trade a somewhat lower single-procedure success rate for a much lower risk of incontinence, which for most people is the right trade.
| Effect | How often | What it means |
|---|---|---|
| Discomfort and discharge | Common | Serous or blood-stained discharge for one to three weeks while the tract heals from within. |
| Swelling around the wound | Common | Settles over one to two weeks. |
| Recurrence of the fistula | Recognised and not rare | The tract fails to seal, or a missed side branch persists. Usually manageable with a further procedure. |
| Delayed healing | Occasional | More likely in smokers, in diabetes, and in Crohn's disease. |
| Infection or new abscess | Occasional | Needs prompt review and sometimes drainage. |
| Urinary retention | Uncommon | Related to anaesthesia. Usually temporary. |
| Bleeding | Uncommon | Usually minor and self-limiting. |
| Change in continence | Uncommon with sphincter preserving techniques | Much less likely than with laying open a transsphincteric tract, which is the reason these techniques exist. |
There is no single best operation for all fistulas. The choice balances the chance of cure against the risk to continence, and depends primarily on how much sphincter the tract crosses.
| Treatment | How it works | Sphincter risk | Best suited to |
|---|---|---|---|
| Fistulotomy (laying open) | The tract is opened along its length and left to heal from the base upward. | High if significant sphincter is crossed | Simple, low, superficial fistulas only. |
| Draining seton | A soft thread is left through the tract to keep it draining and let inflammation settle. | None | A preparatory step, or long-term control in Crohn's disease. |
| FiLaC laser closure | A radial laser fibre seals the tract from within as it is withdrawn. | Low | Transsphincteric and recurrent fistulas where continence must be preserved. |
| LIFT procedure | The tract is tied off and divided in the plane between the sphincters. | Low | Transsphincteric fistulas with a well-defined intersphincteric portion. |
| Advancement flap | The internal opening is covered with a flap of healthy rectal lining. | Low to moderate | Complex or recurrent fistulas with a clear internal opening. |
| VAAFT | The tract is inspected with a fine endoscope, cleaned and closed under direct vision. | Low | Complex tracts where visualising side branches is valuable. |
Techniques are often combined and staged. A seton first, then definitive closure once the tract has settled, is a common and entirely reasonable sequence rather than a sign that something has gone wrong.
A fistula will not close on its own, and waiting rarely improves the situation.
Recurrent abscesses. The tract periodically blocks and pus builds up again, producing a painful swelling that needs draining. Each episode causes further scarring and makes definitive treatment harder.
The tract becomes more complex. Repeated infection creates secondary branches and extensions. A fistula that would have been straightforward becomes a complex, branching problem with a lower chance of cure and a higher chance of needing staged surgery.
Persistent discharge. Continuous soiling of underwear, odour and skin irritation are the daily reality of an untreated fistula, and their effect on confidence and quality of life is considerable.
Rare long-term risk. Very long-standing fistulas, present over many years, carry a small risk of malignant change within the tract. This is uncommon, but it is a further reason not to simply live with the problem indefinitely.
There is no reliable way to prevent a first fistula, since most follow an abscess that itself arises from a blocked gland. What can be influenced is healing after treatment and the chance of recurrence.
Realistic expectations help. Fistula treatment is often a course of care over some months rather than a single operation, and steady progress with occasional setbacks is a normal pattern rather than a sign of failure.
FiLaC laser surgery treats the fistula without cutting a single millimetre of sphincter muscle, eliminating the incontinence risk associated with traditional fistulotomy.
Extensive experience treating simple and complex fistulas, including recurrent and multi-tract cases that have failed previous surgery elsewhere.
No prolonged hospital stay or open wound management needed. Go home the same day and return to normal activity within a few days.
Medical References & Further Reading
This page is written and medically reviewed by Dr. Prashanth J V, MBBS, MS, FMAS, FISCP, DMAS, Karnataka Medical Council Registration No. 41048. It is general health information about anal fistula and does not replace an individual consultation, examination and investigation. If you have symptoms, please seek personalised medical advice.
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