- Equipment
- Proctoscope or anal retractor (I use a Eisenhammer retractor)
- Probe (fistula probe or Lockhart Mammary probe)
- Seton material:
- Common: silicone loop, vessel loop, suture (e.g. silk), or rubber band
- Scalpel, scissors, forceps
- Dilators and swabs
- Optional: hydrogen peroxide or methylene blue (to help identify the tract)
- Technique
- Examination and Identification
- Insert anal retractor
- Identify external opening of the fistula
- Use a probe or cannula to gently pass through the tract toward the internal opening
- Confirm tract course — may inject hydrogen peroxide or methylene blue to visualise the internal opening
- Probe Passage
- Gently pass the probe through the tract — avoid creating false passages
- Seton Placement
- Once the probe is passed through from external to internal opening:
- Thread the seton material through the tract by tying it to the end of the probe
- Pull it through so that the seton exits both the internal and external openings
- Tie the seton in a loose loop — snug enough to keep tract open but not tight enough to cause ischemia
- I use a vessel loop and 2-0 silk tie
- Post-Procedure Care
- Outpatient or day-case procedure
- Provide analgesia and stool softeners
- Daily shower or sitz baths to maintain local hygiene
- Regular follow-up to monitor healing or prepare for second-stage procedure (e.g. fistulotomy, advancement flap, or LIFT)
- Complications
- Discomfort or pain (usually mild with loose setons)
- Infection or persistent drainage
- Migration or loss of seton
- Incontinence (if tract misclassified or inappropriately treated with cutting seton)