Surgical Management of Chronic Anal Fissure
Lateral internal sphincterotomy (LIS) is the most appropriate surgical management for this patient with a chronic posterior anal fissure refractory to conservative treatment. 1
Why Lateral Internal Sphincterotomy is the Gold Standard
LIS achieves healing rates exceeding 95% with recurrence rates of only 1-3%, making it the most effective definitive treatment for chronic anal fissures that have failed conservative management. 1, 2 The American Gastroenterological Association explicitly states that "most surgeons now favor lateral internal sphincterotomy as the procedure of choice for anal fissures that do not resolve with conservative care." 1
Key Performance Metrics of LIS:
- Healing rate: >95% 1, 2, 3
- Recurrence rate: 1-3% 1, 2, 3
- Technical simplicity with minimal morbidity 1
- Rapid symptom amelioration 1
Why the Other Options Are Incorrect
Option A: Anal Dilatation - Absolutely Contraindicated
Manual anal dilatation carries an unacceptably high permanent incontinence risk of 10-30% and is strongly contraindicated by all major guidelines. 2, 4, 5, 6 The World Journal of Emergency Surgery explicitly states this procedure "should not be performed" under any circumstances. 4 This technique has been abandoned in modern practice due to its devastating complications. 6
Option C: Lateral External Sphincterotomy - Wrong Muscle
This is not a recognized procedure for anal fissure treatment. 1 The pathophysiology of chronic anal fissure involves internal anal sphincter hypertonia causing anodermal ischemia. 2 Dividing the external sphincter would not address the underlying sphincter spasm and would cause severe incontinence, as the external sphincter is critical for voluntary continence.
Option D: Curettage and Skin Tag Excision - Inadequate and Potentially Harmful
Simply excising the fissure and skin tag without addressing the underlying sphincter hypertonia will result in high recurrence rates. 1 The ECCO-ESCP guidelines specifically warn that "concomitant perianal skin tags should not be treated surgically as this can lead to chronic, non-healing ulcers." 1 While fissurectomy with advancement flap is used in some centers, it is not the standard of care and has lower evidence support than LIS. 7, 6
Important Caveats About LIS
Risk of Incontinence
LIS carries a small but real risk of minor permanent continence defects, reported in approximately 1-10% of patients, typically manifesting as minor flatus incontinence. 1, 7, 6 However, this risk is significantly lower than the 10-30% permanent incontinence rate with manual dilatation. 2, 4
Patient Selection Considerations
The risk-benefit calculation favors LIS in this 28-year-old man with:
- Chronic fissure (evidenced by skin tag, indicating chronicity >8 weeks) 2, 8
- Failed conservative treatment (explicit in the question) 1, 2
- Young age with presumably normal baseline continence 1
Technical Points
- The sphincterotomy should be performed laterally (at 3 or 9 o'clock position), not posteriorly, to avoid keyhole deformity 1, 6
- The division should extend to the dentate line to adequately reduce sphincter tone 6
- The procedure can be performed open or closed with similar outcomes 6
When to Reconsider LIS
LIS should be avoided or modified in patients with:
- Pre-existing incontinence or weak sphincters 1, 3
- Anterior fissures in women (higher risk of incontinence) 2
- Crohn's disease or inflammatory bowel disease (requires different management) 1
- Atypical fissure locations (lateral or multiple fissures suggest underlying pathology) 2, 5
In such cases, botulinum toxin injection (75-95% cure rates) or advancement flap procedures may be considered as sphincter-sparing alternatives. 1, 3, 7