It is an ulcer in the longitudinal axis of the lower anal canal.
- Midline posteriorly- most common (more common in males)
- Midline anteriorly- next most common (more common in females)
- Due to the curvature of the sacrum and rectum, hard fecal matter while passing down causes a tear in the anal valve leading to posterior anal fissure.
- Anterior anal fissure is common in females due to lack of support to the pelvic floor.
- IBD- esp. chron’s disease
- It can be acute and chronic. Fissure ends above at the dentate line.
- Acute anal fissure
- It is a deep tear in the lower anal skin with spasm of anal sphincter with little inflammatory induration or edemaof its edges.
- Chronic anal fissure
- It has got inflamed, indurated margin with scar tissue.
- Ulcer at its inferior margin is having a skin tag, which is edematous, acts like a guard-’ Sentinel Pile’
- It can cause repeated infection-fibrosis-abscess foramtion-fistula formation.
- Common in middle aged women, not in elderly.
- Pain is severe in nature in acute type, whereas less severe in chronic.
- Constipation, bleeding and discharge.
- In standing cases there may be sentinel skin tag. Sentinel skin tag + typical Hx + tightly closed, puckered anus= pathognomonic.
- In chronic fissure, ulcer is felt with button like depression, induration and often sentinel pile.
- The lower end of the fissure can be seen by gently parting the margins of anus.
- Digital examination and proctoscopy is not possible in acute fissure in ano.
- Carcinoma of anus
- Inflammatory bowel disease
- Venereal diseases
- Anal chancre
- Tuberculous ulcer
- Proctalgia fugax
- NO- neurotransmitter that induces relaxation of the internal spchicter.
- Glyceryl trinitrate- being nitric acid donor, when applied as an ointment causes relaxation of the sphincter and also improves blood flow- both aids healing.
- Use of laxatives and xylocaine surface anaesthetic.
Gentle dilatation of the sphincter under GA:
- Can be used in young men with high pressure sphincter.
- CI in pts. with weak sphincter.
- If this method is ineffective or if the fissure is chronic with fibrosis, a skin tag or a mucus polyp, then surgery is done under GA(best) or LA.
Lateral anal sphincterotomy:
- Here internal sphincter is divided away from the fissure either in right or left lateral positions.
- Can be done in OPD basis under L/A.
- Healing completes in 3 wks.
- Good result for acute than chronic cases.
- Small risk of incontinence.
Closed and open
- Here excision of the edges of the fissure and mobilization of a square, full-thickness anal skin flap which is slided forward over the fissure and sutured in place.
- Only little risk of damage to the underlying internal sphincter and incontinence is unlikely.