- Indications
- Obstetric anal sphincter injury (OASI) with disruption of the external anal sphincter (EAS)
- Traumatic anterior sphincter defect (e.g. after episiotomy, perineal trauma)
- Structural anterior sphincter defect on endoanal ultrasound/MRI with symptoms of faecal incontinence
- Failed conservative measures (e.g. pelvic floor physiotherapy, biofeedback)
- Pre-Procedure Preparation
- Full continence assessment: history, anorectal physiology, endoanal US or MRI
- Bowel preparation (usually phosphate enema pre-op)
- Discuss risk of wound breakdown, infection, and recurrence
- Informed consent including alternatives (e.g. sacral nerve stimulation)
- Prophylactic antibiotics at induction
- Technique
- Position and Exposure
- Lithotomy or prone jack-knife position
- Prep and drape perineum; insert Foley if needed
- Incision and Dissection
- Make a transverse or curved perineal incision just below the vaginal introitus
- Dissect through scar tissue to expose disrupted ends of the external anal sphincter
- Protect the vaginal and rectal mucosa during dissection - place a finger in the rectum/vagina to aid this
- Mobilise sphincter ends for at least 2–3 cm each side to allow overlap
- Sphincter Repair
- Identify and separate EAS from IAS (internal anal sphincter) if possible
- Two main options:
- End-to-end repair: suture the two sphincter ends directly together
- Overlapping repair (preferred): mobilise each end and overlap one over the other, then suture in layers
- Use interrupted absorbable sutures through the muscle bulk
- I use 3-0 PDS
- Check tension — repair should not be tight
- Perineal Body Reconstruction
- Reconstruct the perineal body with deep sutures
- Reapproximate subcutaneous fat and close skin (interrupted or subcuticular sutures)
- Position and Exposure
- Post-Procedure Care
- Catheter for 24–48 hours to prevent urinary retention
- Stool softeners and high-fibre diet to avoid straining
- Analgesia, including avoiding constipation-inducing opioids
- Advise no intercourse or heavy lifting for 6 weeks
- Pelvic floor physiotherapy after healing (around 6–8 weeks)
- Complications
- Wound infection or dehiscence
- Perineal pain or dyspareunia
- Recurrence of incontinence (especially long-term)
- Fistula formation
- Failure to improve due to underlying neuropathy
https://www.youtube.com/watch?v=AWuBTmaU4XM&ab_channel=ColorectalDiseaseJournal
Acute vs elective
- Acute
- May be more appropriate to perform an end to end repair
- Internal and external muscle should be repaired separately
- Likely the vaginal and rectal mucosa will need to be repaired
- Elective
- Mass overlapping repair likely more appropriate given scar tissue
- Keep mucosa intact