Lateral internal sphincterotomy
|Lateral internal sphincterotomy|
Lateral internal sphincterotomy is an operation performed on the internal anal sphincter muscle for the treatment of chronic anal fissure. The internal anal sphincter is one of two muscles that comprise the anal sphincter which controls the passage of feces. The procedure helps by lowering the resting pressure of the internal anal sphincter, which improves blood supply to the fissure and allows faster healing. The procedure has been shown to be very effective, with 96% of fissures healing at a median of 3 weeks in one trial.
Lateral internal sphincterotomy is the preferred method of surgery for persons with chronic anal fissures, and is generally used when medical therapy has failed. It is associated with a lower rate of side effects than older techniques such as posterior internal sphincterotomy and anoplasty, and has also been shown to be superior to topical glyceryl trinitrate (GTN 0.2% ointment) in long term healing of fissures, with no difference in fecal continence.
Lateral internal sphincterotomy is a minor operation which can be carried out under either local or general anaesthesia; a report in 1981 showed that general anaesthesia is preferable due to high rates of fissure recurrence in patients treated under local anaesthesia. This operation is generally carried out as a day case procedure. It can be performed with either "open" or "closed" techniques:
- the open technique involves making an incision across the intersphincteric groove, separating the internal sphincter from the anal mucosa by blunt dissection, and dividing the internal sphincter using scissors.
- the closed technique or subcutaneous technique involves making a small incision at the intersphincteric groove, inserting a scalpel with the blade parallel to the internal sphincter and advancing it along the intersphincteric groove, and then rotating the scalpel towards the internal sphincter and dividing it.
In both techniques the lower one third to one half of the internal sphincter is divided, to lower the resting pressure without destroying the effect of the sphincter. The closed technique results in a smaller wound, but both techniques appear to be similarly effective.
- Minor fecal incontinence and difficulty controlling flatulence are common side effects following surgery. Persistent minor fecal incontinence has been reported in 1.2% to 3.5% of patients; however, this does not appear to be significantly different to the rate of minor fecal incontinence experienced by patients treated with topical GTN.
- Hemorrhage can occur, more often with the open technique, and may require suture ligation.
- Perianal abscess occurs in about 1% of closed sphincterotomies, generally in association with anal fistula caused by a breach of the anal mucosa by the scalpel. Incision and drainage of the abscess and fistulotomy are required.
- Schubert MC, Sridhar S, Schade RR, Wexner SD (July 2009). "What every gastroenterologist needs to know about common anorectal disorders". World J. Gastroenterol. 15 (26): 3201–9. PMC . PMID 19598294. doi:10.3748/wjg.15.3201. Retrieved 2009-12-05.
- Nyam DC, Pemberton JH (October 1999). "Long-term results of lateral internal sphincterotomy for chronic anal fissure with particular reference to incidence of fecal incontinence". Dis. Colon Rectum. 42 (10): 1306–10. PMID 10528769. doi:10.1007/BF02234220.
- Bailey RV, Rubin RJ, Salvati EP (1978). "Lateral internal sphincterotomy". Dis. Colon Rectum. 21 (8): 584–6. PMID 738174. doi:10.1007/BF02586402.
- Brown CJ, Dubreuil D, Santoro L, Liu M, O'Connor BI, McLeod RS (April 2007). "Lateral internal sphincterotomy is superior to topical nitroglycerin for healing chronic anal fissure and does not compromise long-term fecal continence: six-year follow-up of a multicenter, randomized, controlled trial". Dis. Colon Rectum. 50 (4): 442–8. PMID 17297553. doi:10.1007/s10350-006-0844-3.
- Keighley MR, Greca F, Nevah E, Hares M, Alexander-Williams J (June 1981). "Treatment of anal fissure by lateral subcutaneous sphincterotomy should be under general anaesthesia". Br J Surg. 68 (6): 400–1. PMID 7016242. doi:10.1002/bjs.1800680611.
- Corman, Marvin L (2005). Colon and rectal surgery (5 ed.). Lippincott Williams & Wilkins. p. 264. ISBN 978-0-7817-4043-2.
- Nelson, Richard L. (2010-01-20). "Operative procedures for fissure in ano". The Cochrane Database of Systematic Reviews (1): CD002199. ISSN 1469-493X. PMID 20091532. doi:10.1002/14651858.CD002199.pub3.
- Khubchandani IT, Reed JF (May 1989). "Sequelae of internal sphincterotomy for chronic fissure in ano". Br J Surg. 76 (5): 431–4. PMID 2736353. doi:10.1002/bjs.1800760504.