Sphincter Reconstruction in the Context of Fistulotomy
Sphincter reconstruction after fistulotomy is a surgical technique where the anal sphincter muscle is immediately repaired following the laying open of a complex anal fistula tract, specifically designed to prevent postoperative incontinence in patients at high risk for continence disturbance. 1, 2
What the Procedure Involves
The technique consists of two sequential steps performed during the same operation:
First, complete fistulotomy is performed by laying open the entire fistula tract from internal to external opening, with thorough debridement of all granulation tissue and secondary tracts 1, 2
Second, immediate sphincter repair is performed using either an end-to-end or overlapping technique to reconstruct the divided sphincter muscle, typically with absorbable sutures 3, 4
The sphincter ends are identified, mobilized, and approximated without tension, restoring anatomical continuity of the muscle 2
Specific Indications for This Approach
This technique should be reserved for highly selected patients who meet specific criteria:
Complex fistulas involving significant sphincter muscle, particularly mid-to-high transsphincteric fistulas (involving upper two-thirds of external sphincter), suprasphincteric, or extrasphincteric fistulas 1, 2
Patients with pre-existing fecal incontinence from prior fistula surgery or obstetric injury, where simple fistulotomy would worsen continence 1, 2
Recurrent fistulas where previous operations have already compromised sphincter integrity 1, 4
Multiple or complex fistula tracts where extensive sphincter division is unavoidable 5
Critical Patient Selection Criteria
The procedure should NOT be performed in patients with:
- Active proctitis or rectosigmoid inflammation, which dramatically impairs healing 6
- Crohn's Disease Activity Index >150 6, 7
- Evidence of perineal Crohn's disease involvement 6, 7
- Active abscess that has not been adequately drained 7, 8
Clinical Outcomes and Evidence Quality
The most recent high-quality evidence demonstrates:
Healing rates of 90-96% at medium-term follow-up (24-32 months), comparable to fistulotomy alone 5, 4
Recurrence rates of only 5.7-9.7%, which is acceptably low 3, 2, 4
Improvement in continence scores for patients with pre-existing incontinence, with mean Wexner scores decreasing from 7.2 to 2.0 postoperatively 2
De novo minor incontinence (postdefecation soiling) occurs in 11.6-20% of previously continent patients, but major incontinence is rare (4%) 3, 4
No increased risk of septic complications compared to fistulotomy alone (6.7% vs 3.7%, not statistically significant) 5
Key Technical Considerations
To optimize outcomes, the surgeon must:
Perform complete excision of the fistula tract and all granulation tissue before sphincter repair 1, 2
Achieve tension-free approximation of healthy sphincter muscle ends 2, 4
Use absorbable sutures for the sphincter repair 4
Avoid aggressive probing that could create iatrogenic complexity 6, 7
Common Pitfalls to Avoid
The most critical errors include:
Attempting this procedure in the presence of active inflammation or proctitis, which leads to wound dehiscence and failure 6
Using this technique for simple low fistulas where standard fistulotomy would suffice 7, 8
Performing the procedure in patients with recurrent fistulas after multiple prior surgeries, who have 5-fold increased risk of continence impairment 4
Inadequate drainage of associated abscesses before definitive repair 7, 8
Comparison to Alternative Approaches
While sphincter reconstruction after fistulotomy offers immediate definitive treatment, alternative approaches exist:
Loose seton drainage remains the gold standard for complex fistulas with inflammation, with seton removal possible in up to 98% at median 33 weeks when combined with medical therapy 6, 8
Endorectal advancement flap achieves 64% success in Crohn's patients and 80% in cryptoglandular fistulas, but requires absence of rectal inflammation 6, 8
Standard fistulotomy alone is appropriate for simple low fistulas not involving significant sphincter muscle 7, 8
The advantage of immediate sphincter reconstruction is that it allows complete fistula excision while attempting to preserve continence in a single operation, avoiding the need for staged procedures 1, 3. However, this must be weighed against the 11-20% risk of minor continence disturbance in previously continent patients 3, 4.
Special Considerations for Crohn's Disease
In Crohn's disease patients specifically:
Control luminal disease with thiopurines or anti-TNF therapy before and after surgery 7, 8
Assess for proctitis at time of surgery, as active inflammation is an absolute contraindication 6, 8
Consider loose seton as definitive treatment combined with medical therapy rather than sphincter reconstruction 6, 8
Success rates are lower in Crohn's patients (64%) compared to cryptoglandular fistulas (80%) 6, 8