Why is laying open from the inside not recommended for treating this patient's anal fistula?

Why Laying Open From Inside is Not Recommended for Anal Fistula Treatment

Laying open from the inside (fistulotomy) is not recommended for treating anal fistulas because it carries a high risk of incontinence (up to 57%) due to transection and scarring of the anal sphincter, particularly in complex fistulas and female patients with anterior fistulas. 1

Risks of Fistulotomy (Laying Open)

• High incontinence risk: The cutting technique results in transection and scarring of the anal sphincter, with incontinence rates as high as 57% 1
• Keyhole deformity: Can develop after fistulotomy, especially with cutting setons 1
• Anatomical considerations: Particularly dangerous in:
  • Female patients with anterior fistulas (due to shorter anterior sphincter) 1
  • Complex fistulas involving >30% of external sphincter 2
  • Patients with Crohn's disease with active inflammation 1

Appropriate Indications for Fistulotomy

Fistulotomy should be limited to:

1. Subcutaneous or superficial fistulas 1
2. Submucosal fistulas 1
3. Intersphincteric fistulas in the lower third of the anal sphincter 1
4. Simple, low transsphincteric fistulas (with careful patient selection) 2

Contraindications for Fistulotomy

• CDAI greater than 150 (active Crohn's disease) 1
• Evidence of perineal Crohn's disease involvement 1
• Female patients with anterior fistulas 1
• Complex fistulas involving significant sphincter portions 1
• Intersphincteric fistulas without external opening 3

Preferred Alternative Approaches

1. Seton Placement

• Primary role: Drainage of sepsis and prevention of abscess formation 1
• Technique: Loose, fine silastic setons placed through the fistula tract 1
• Timing: Should remain in place until induction of anti-TNF treatment is completed (approximately one month) 1
• Success rate: When combined with optimal medical therapy, setons can be removed in up to 98% of patients at a median of 33 weeks 1

2. LIFT Procedure (Ligation of Intersphincteric Fistula Tract)

• Success rate: 65-77% in complex fistulas 3, 73% primary healing in another study 4
• Advantages:
  • Preserves sphincter function and continence 3, 4
  • Avoids surgery on potentially diseased mucosa 3
  • Particularly suitable for single, non-branching fistula tracts 3
  • Low complication rate (up to 14%, primarily wound dehiscence) 3

3. Endorectal Advancement Flap

• Technique: Internal opening of fistula closed with partial or full-thickness rectal flap 1
• Best for: High fistulas (upper two-thirds of sphincter complex) and rectovaginal fistulas 1
• Success rate: 64% (range 33-92%) for Crohn's fistulas 1
• Considerations: Poor wound healing may occur with active rectal Crohn's disease or in smokers 1

4. Newer Techniques (Limited Evidence)

• Video-assisted anal fistula treatment (VAAFT): Insufficient evidence for recommendation in CD 1
• Fistula-tract laser closure (FiLaC): Pooled healing rate of 68% in limited studies 1
• Over-the-scope clip (OTSC): Limited data, potential for spontaneous passage 1
• Transanal opening of intersphincteric space (TROPIS): Promising technique for high complex fistulas with 84.6-90.4% healing rates 5, 2

Treatment Algorithm for Anal Fistulas

1. Assess fistula complexity and location:

   • Simple vs. complex
   • Anterior vs. posterior
   • Involvement of sphincter complex
   • Presence of active proctitis

2. For simple, superficial fistulas:

   • Fistulotomy may be appropriate if minimal sphincter involvement 1, 2

3. For complex fistulas:

   • Initial seton placement to control sepsis 1
   • After control of inflammation:
     • LIFT procedure for intersphincteric fistulas 3, 4
     • Endorectal advancement flap for high transsphincteric fistulas 1
     • Consider diversion for severe, refractory cases 1

4. For female patients with anterior fistulas:

   • Avoid fistulotomy completely 1
   • Consider sphincter-preserving techniques only 1, 2

5. For patients with Crohn's disease:

   • Control proctitis with medical therapy before definitive surgical treatment 1
   • Consider combined approach with anti-TNF therapy and seton placement 1

Remember that the primary goal of treatment is to eradicate sepsis and promote healing while preserving sphincter function and preventing incontinence.