This study is aimed at studying the effectiveness and safety of surgical treatment of chronic anal fissure.

A chronic anal fissure is a rupture of the mucous membrane of the anal canal, lasting more than 2 months and resistant to non-surgical treatment. This condition is accompanied by a strong pain syndrome during and after defecation (defecation). This condition is most often found in young and able-bodied adults, so the issue of treatment is of particular relevance.

The main cause of the development of a chronic anal fissure is a spasm of the internal sphincter. It should be eliminated first of all to ensure effective therapy. All the main treatment methods, such as medicinal relaxation of the internal sphincter with 0.4% nitroglycerin ointment, lateral subcutaneous sphincterotomy, and pneumodivulsion of the anal sphincter are aimed at its removal. However, the optimal method has not yet been developed.

Non-surgical treatments are often attended by relapse of disease, while surgical treatment is often complicated by intestinal contents incontinence, usually gas and loose or hard stool in some occasions (grade 3 anal sphincter insufficiency).

In particular, lateral subcutaneous sphincterotomy performed in such patients is associated with an increase in the degree of anal incontinence in the early post-operative period.

Botulinum Toxin Type A application in treatment of patients with chronic anal fissure (after fissure excision) is intended to improve the therapy results, namely to reduce the frequency and duration of anal sphincter insufficiency after sphincter spasm removal (reduction in the number of patients suffering from post-operative incontinence).

Inclusion Criteria:

• Patients with chronic anal fissure with spasm of anal sphincter

Exclusion Criteria:

• Inflammatory diseases of the colon
• Pectenosis
• Previous surgical interventions on the anal canal
• IV grade internal and external hemorrhoids
• Rectal fistula
• Severe somatic diseases at the decompensation stage
• Pregnancy and lactation
• Anal sphincter insufficiency
• Chronic paraproctitis
• Fibrous polyp of the anal canal, accompanied by clinical manifestations
• Individual intolerance and hypersensitivity to botulinum toxin
• Myasthenia gravis and myasthenic syndromes