Lateral internal sphincterotomy is still crucial to heal hypertonic chronic anal fissure and normalize the internal anal sphincter tone? Is V-en Y plastic a valuable alternative?

INTRODUCTION: The role of augmented internal anal sphincter (IAS) tone in the genesis of chronic anal fissure (CAF) is still unclear. Lateral internal sphincterotomy (LIS) is the most employed surgical procedure, aiming to reduce the IAS tone leaving a permanent anatomical alteration and it is burdened by high risk post-operative anal incontinence (AI). The aim of this work was to evaluate if the pre-operative manometric alterations of CAFs with hypertonic IAS would normalize after sphincter preserving surgical procedure. METHODS: We enrolled 108 consecutive patients affected by idiopathic and non-recurrent CAF undergone fissurectomy and anoplasty with V-Y cutaneous flap advancement and pharmacological sphincterotomy, matched with 54 healthy subject in a 1 to 2 ratio, and followed up for at least for 2 years. The goals were patient’s complete healing, the evaluation of AI, recurrence rate and manometry parameters. RESULTS: All wounds healed within 40 days after surgery. We recorded 7 cases of recurrences healed with medical therapy. We recorded 3 “de novo” post-operative cases of AI all temporary and low grade. Pre-operative values of maximum resting pressure (MRP) and detection of ultraslow wave activity (USWA) were significantly higher than in the healthy control group, but both come back to be similar to those recorded in healthy subject after 24 months from the surgery. CONCLUSION: The high healing rate without post-operative “de novo” AI cases with the normalization of manometric parameters suggest that fissurectomy and anoplasty with V-Y cutaneous advancement flap and pharmacological sphincterotomy is an adequate procedure for the treatment of CAF with IAS hypertonia.