Lateral Internal Sphincterotomy"
effective in acute fissures.
Open or closed technique possible.
Key Operative Points
Insert a Parks
anal retractor stretching the IAS
Palpate sphincters and identify the intersphincteric groove
Make a 1cm incision at the base of the internal sphincter on the
right lateral side
- right side a little easier because on the left there is a lateral
haemorrhoid in this position.
Insert a crile and open the inter-sphincteric space.
Then open space on other side of the sphincter with the crile
Grasp the required amount of sphincter with an Allis forcep
- usually to uppermost aspect of fissure in tailored fashion.
- often to just below the dentate line
Place a crile over the top of the Ellis, and controlled diathermy
under vision to the selected amount of muscle.
Apply pressure for haemostasis if required
Leave mucosa intact
One stitch on medial half of incision, to prevent bowel motion
entering wound; leave other half open.
Excise any sentinel skin tags and hypertrophied anal papillae.
Apply a perineal pad and pants
The fissure then hopefully heals within three weeks of dividing the
Recurrence rate is low, probably <5%.
- 1 in 20 chance of some flatus incontinence, typically
- soiling in up to 5% (major incontinence is rare; i.e. <1%).
- minimized with good technique, tailored approach, controlled
- risk correlated to length of sphincterotomy.
- prolapsed haemorrhoids, haemorrhage, perianal abscess,
fistula-in-ano each complicate <1% of cases.
Failure may be due to incomplete sphincterotomy
Alternatives and Controversies
Do it closed.
open = better visually, but
perhaps greater complications.
- proponents of each state their better with evidence.
- unhealed recurrence may be lower with open.
closed = safer; less damage to external sphincters.