Published: 2019-05-28

Outcome of bilateral versus unilateral lateral internal sphincterotomy for chronic anal fissures

Majid Mushtaque, Umar Q. Bacha, Arshad Rashid, Tajamul N. Malik, Samina A. Khanday


Background: Gold standard treatment for chronic anal fissure is lateral internal sphincterotomy (LIS) which is usually performed at a single location. This randomized study compares bilateral to unilateral lateral internal sphincterotomy.

Methods: Patients were randomized into two equal groups (64 each) to undergo either bilateral (Group A) or unilateral (Group B) open lateral internal sphincterotomy (LIS). Comparative study was done in terms of symptomatic relief of pain, incontinence, complete healing of fissure, and recurrence. Chi-square test was used as a test of significance.

Results: Both groups had comparable demographic and clinical characteristics. Mean operative time for was longer for bilateral LIS (P-value <0.05). Mean pain score (VAS) in bilateral LIS group was lower in early post-operative period (P-value <0.05). At the end of 4th week 65.6% of patients in bilateral LIS group and 56.25% of patients in unilateral LIS group had completely healed fissures (P-value <0.05). Mean Wexner score for incontinence was comparable, while significant decrease in resting anal pressure was noted at 1 month in BLIS group. There was one recurrence in unilateral LIS group.

Conclusions: Bilateral LIS resulted in better outcome in terms of early pain relief, early reduction of anal pressures, complete healing rate in 4 weeks with no recurrence. It does not increase the risk of incontinence and has better patients’ satisfaction as compared to unilateral LIS.


Bilateral sphincterotomy, Chronic anal fissure, Incontinence, Lateral internal sphincterotomy

Full Text:



Utzig MJ, Krosean AJ, Buhr HJ. Concepts in pathogenesis and treatment of chronic anal fissure-a review of literature. Am J Gastroenterol. 2003;8:968-74.

Kodner IJ, Fry RD, Fleshman JW, Birnbaum EH, Read TE. Colon rectum and anus. In: Schwartz principles of surgery, 7th edition. USA: McGraw Hill health professions divisions; 1999: 1265-1269.

Gibbons CP, Read NW. Anal hypertonia in fissures: Cause or effect? Br J Surg. 1986;73:443-5.

Herzig DO, Lu KC. Anal fissure. Surg Clin North Am. 2010;90:33-44.

Corby H, Donnelly VS, O’ Herlihy C, O Connel PR. Anal canal pressure are low in women with postpartum anal fissures. Br J Surg. 1987;84:86-8.

Klosterhalfen B, Vogel P, Rixen H, Mittermajec C. Topography of the inferior rectal artery: a possible cause of chronic, primary anal fissure. Dis Colon Rectum. 1989;32(1):43-52.

Ebinger SM, Hardt J, Warschkow R, Schmied BM, Herold A, Post S, et al. Operative and medical treatment of chronic anal fissures-a review and network meta-analysis of randomized controlled trials. J Gastroenterol. 2017;52(6):663-76.

Pujahari AK. Unilateral versus bilateral lateral internal sphincterotomy:A randomized controlled trial for chronic fissure in ano. Tropical Gastroenterol. 2010;31(1):69-71.

Pilkington SA, Bhome R, Welch RE, Ku F, Warden C, Harris S, et al. Bilateral versus unilateral botulinum toxin injections for chronic anal fissure: a randomised trial. Techniques in coloproctology. Techniques in Coloproctol. 2018;22:545-51.

McNamara MJ, Percy JP, Fielding IR. A manometric study of anal fissure treated by subcutaneous lateral internal sphincterotomy. Ann Surg. 1990;211:235-8.

Eisenhammer S. The evaluation of the internal anal sphincterotomy operation with special reference to anal fissure. Surg Gynecol Obstet. 1959;109:583-90.

Notaras MJ. Lateral subcutaneous sphincterotomy for anal fissure. A new technique. Proc R Soc Med. 1969;62:713.

Nahas SC, Sobrado Jr CW, Araujo SE, Aisaaka AA, Habar GA, Pinotti HW. Chronic anal fissure: results of the treatment of 220 patients. Rev Hosp Clin Fac Med. 1997;52:246-9.

Melange M, Colin JF, Van Wynersch T, Van Heuverzwyn R. Anal fissure: correlation between symptoms and manometry before and after surgery. Int J Colorectal Dis. 1992;7:108-11.

Aun C,Lam YM,Collect B.Evaluation of the use of visual analogue scale in Chinese patients. Pain. 1986;25:215-21.

Uz A, Elhan A, Ersoy M, Tekdemir I. Internal anal sphincter: an anatomic study. Clin Anat. 2004;17:17-20.

Bansal AR, Tripura R, Godara R, Jaikaran. Comparative study of glyceryl trinitrate ointment versus lateral internal sphincterotomy in management of chronic anal fissure. Arch Clin Gastroenterol. 2016;2(1):13-6.

Oettle GJ. Glyceryl trinitrate vs. sphincterotomy for treatment of chronic fissure-in-ano: a randomized, controlled trial. Dis Colon Rectum. 1997;40:1318-20.

Mente BB, Ege B, Leventoglu S, Oguz M, Karadag A. Extent of lateral internal sphincterotomy: up to the dentate line or up to the fissure apex? Dis Colon Rectum. 2005;48(2):365-70.

Elsebae MM. A study of fecal incontinence in patients with chronic anal fissure: prospective, randomized, controlled trial of the extent of internal anal sphincter division during lateral sphincterotomy. World J Surg. 2007;31(10):2052-7.

McCallion K, Gardiner KR. Progress in the understanding and treatment of chronic anal fissure. Postgrad Med J. 2001;77(914):753-8.