Randomized control trial on unilateral vs bilateral lateral internal sphincterotomy in a case of chronic fissure in ano

Gold standard treatment for chronic anal fissure is LIS, which is usually performed at single location, this study compares unilateral vs bilateral open LIS. Anal fissure is a painful linear mucosal tear situated in distal anal canal just below dentate line to anal verge, affects all ages and both sexes. Patient characteristically presently with pain, brigh red bleeding, mucosal discharge and constipation. Injury to anal mucosa by hard stools is the initiating event in the developement of fissure. Fissures classified into acute and chronic and into primary and secondary based on the pathogenesis. Chronicity criteria is duration of symptoms more than 8 weeks, presence of sentinal tag or ulcer with exposed internal sphincter. Aim is to reduce the sphicter tone which in turn increases vascularity, with medical (GTN, CCB, BOTULINUM TOXIN)  or surgical intervention(LIS).

Internal sphincter is formed by circular muscle fibers, dividing it at one point of the circle relaxes the tone of the sphincter, which is the rationale for doing unilateral LIS. Dividing the sphicter, which is rationale for doing unilateral LIS. Dividing the sphincter at two places relaxes the sphicter effectively and helps in healing faster and recovery. However risk of incontinence may increase.