What are the steps for an anal sphincterotomy (surgical incision of the anal sphincter)?

From the Guidelines

Lateral internal sphincterotomy is the preferred technique for treating chronic anal fissures, with a lower recurrence rate, higher patient satisfaction, and a healing rate of over 90%. When performing an anal sphincterotomy, the procedure typically begins with patient positioning in either lithotomy, prone jackknife, or lateral position under appropriate anesthesia (local with sedation, regional, or general) 1. The steps involved in the procedure include:

• Patient positioning and anesthesia
• Sterile preparation and draping
• Digital rectal examination to assess sphincter tone and locate the fissure
• Insertion of a lubricated anoscope to visualize the anal canal
• Identification of the internal sphincter muscle and careful division using scissors or electrocautery, typically extending from the dentate line to just below the fissure (partial sphincterotomy)
• Confirmation of the adequacy of the sphincterotomy by feeling the divided muscle edges
• Achievement of hemostasis using pressure, electrocautery, or suture ligation if needed
• Wound closure or leaving it open to heal by secondary intention

The decision to perform an anal sphincterotomy should be made after a patient has failed to respond to 6-8 weeks of non-operative management, as suggested by the guidelines for anorectal emergencies 1. Both open and closed lateral internal sphincterotomy techniques have similar results, although open lateral internal sphincterotomy may be associated with higher post-operative pain and delayed wound healing at 1 year 1. The goal of the procedure is to reduce anal canal pressure, improve blood flow to the fissure, and allow healing while maintaining sufficient sphincter function for continence. Postoperatively, patients require pain management, stool softeners, sitz baths, and follow-up to monitor healing and continence.

From the Research

Anal Sphincterotomy Steps

The steps involved in anal sphincterotomy are not explicitly outlined in the provided studies. However, the following information can be gathered:

• Lateral internal sphincterotomy is a surgical procedure used to treat chronic anal fissure 2, 3, 4.
• The procedure involves making an incision in the internal anal sphincter to relieve spasm and promote healing 2, 3, 4.
• There are different techniques for performing lateral internal sphincterotomy, including open and closed methods 4.
• The choice of technique may depend on the individual patient and the surgeon's preference 4.
• Anal sphincterotomy can be performed using surgical or biologic methods, such as injecting botulinum toxin into the internal anal sphincter 3.

Key Considerations

• The goal of anal sphincterotomy is to relieve internal anal sphincter spasm and promote healing of the fissure 2, 3.
• The procedure can be effective in treating chronic anal fissure, but it carries a risk of complications, such as fecal incontinence 5, 2.
• The use of topical nifedipine and botulinum toxin injections may be an alternative to surgical sphincterotomy in some cases 5, 6, 3.
• The choice of treatment should be individualized based on the patient's specific needs and medical history 5, 2, 6, 3, 4.

Surgical Techniques

• Open lateral internal sphincterotomy involves making an incision in the skin and muscle to access the internal anal sphincter 4.
• Closed lateral internal sphincterotomy involves making a smaller incision and using a specialized instrument to divide the internal anal sphincter 4.
• The closed technique may be associated with less postoperative pain and a shorter hospital stay compared to the open technique 4.