[Efficacy of anal dilators in the treatment of acute anal fissure. A controlled clinical trial].

Procedures involving the use of anal dilators or topical nitroderivatives for the treatment of anal fissure are efficacious, economic and safe. The aim of our study was to compare the efficacy of two conservative treatments - passive dilation with anal dilators or topical nitroderivatives - in reducing anal pressure and resolving anal fissures. A total of 40 patients with a clinical diagnosis of acute anal fissure in the absence of hypotonic anal sphincter, abscess or perianal fistula, haemorrhoidal thrombosis, chronic inflammatory bowel disease or lower gastrointestinal neoplasia were randomly assigned to treatment with dilators (20 patients) or topical nitroderivatives (20 patients). After 4 weeks of treatment, 90% of patients treated with dilators and only 45% treated with topical nitroderivatives showed complete resolution of their anal fissures and a reduction of sphincter hypertone. After 12 weeks, 2/18 patients successfully treated with dilators and 1/9 patients successfully treated with topical derivatives presented recurrence of the anal fissure. The use of anal dilators would appear to induce better resolution of acute anal fissures than topical nitroderivates, as confirmed by the low relapse rate at 12 weeks.