Safety and effectiveness of minimal sphincterotomy in the treatment of female patients with chronic anal fissure.

To evaluate the outcome of a left lateral internal sphincterotomy extended for 20% of total sphincter length in female patients with chronic anal fissure, high anal resting pressure and normal preoperative anal continence. Between January 2014 and January 2018 all the female patients with chronic anal fissure showing failure of medical therapy, perfect anal continence (Cleveland Clinic Florida incontinence score = 0) and high anal resting pressure underwent a lateral internal sphincterotomy extended for 1/5 of total lateral sphincter length, basing on the preoperative measurements by three-dimensional endoanal ultrasound. Postoperative follow-up included clinical assessment at 3, 6 and 12 months associated with manometric and ultrasonographic evaluation at 6 months. Thirty-two patients, [median age 45 (range 19-68)] were included and, of these, 2 (6.2%) were lost to follow-up. At 6 month follow-up success rate was 93.3% (28/30) and continence score was 0 in all the patients. Two patients (6.2%) with poor outcome showed incomplete sphincterotomy at EAUS and underwent re-surgery. At three-dimensional endoanal ultrasound the median length of sphincterotomy was 6 mm (5-8.2). At 12 month follow-up the success rate was 100% and Cleveland Clinic Florida incontinence score remained 0 in all the cases. Open left lateral internal sphincterotomy extended for about 20% of total left lateral internal sphincter length seems to be safe and effective in the treatment of chronic anal fissure in suitable female patients achieving a high success rate without compromising anal continence.