anal fissure

Question 1

definition of anal fissure

Answer 1

a longitudinal tear in the squamous epithelium of the distal anal canal

Question 2

aetiology of anal fissure

Answer 2

passage of a large, hard stool = pain and sphincter spasm that interfers with local blood supply and so healing

self perpetuating cycle of pain, spasm and re-injury

RF - constipation

Question 3

pathology of anal fissure

Answer 3

nearly always in midline of posterior anal margin - from anal margin to below denate line - probably because this area is a vascular watershed and so is susceptible to poor healing

varying depth - granulation tissue or fibres of the external anal sphincter visible

10% in women, and 1% in men are anterior

Question 4

epidemiology of anal fissure

Answer 4

common

any age esp 30-5yrs and children

Males>females slightly

Question 5

sx of anal fissure

Answer 5

fresh blood separate to stool or on paper

severe acute pain on anus on defecation - for minutes-hours

subsequent fear of defecation and constipation

Question 6

signs of anal fissure

Answer 6

on inspection - small linear cut, often concealed by sphincter spasm

chronic fissure associated with sentinel pile - small skin tag present on anal verge

DRE may be aided by LA, but often not possible because of pain

Question 7

ix of anal fissure

Answer 7

history and exam under LA if necessary

if not in midline - biopsy because could be due to infection (syphilitic chancre, herpes simplex, TB), IBD, or malignancy

Question 8

medical mx of anal fissure

Answer 8

chemical sphincterotomy

• topical application on 0,2% glyceryl trinitrate ointment
• releases local nitric oxide - mediate sm relaxation = reduced spasm = healing
• SE = headache

topical CCB, diltazem and injections of botulinum toxin

LA gel (1% lidocaine) before defecation

laxatives

high fibre diet, increase water intake and appropriate exercise

Question 9

surgical mx of anal fissure

Answer 9

when failure of conservative treatment

lateral submucous (internal) sphincterotomy involves division of fibres of internal sphincter at 3 o clock, distal to line of anal valves

risk of incontinence/flatus for variable period after

Question 10

complications of anal fissure

Answer 10

abscess or fistula

15% undergoing surgery = flatus/incontinence

Question 11

Px of anal fissure

Answer 11

good with glyceryl trinitrate - cure up to 60%

may become chronic if left untreated