Long-term Efficacy and Safety of Controlled Manual Anal Dilatation in the Treatment of Chronic Anal Fissures: A Single-center Observational Study

OBJECTIVES: Conventional anal dilatation for anal fissures has long been abandoned because of the high incidence of anal incontinence. However, less invasive and more precise dilation techniques have been developed that have shown high healing and low incontinence rates. This study aimed to evaluate the efficacy and safety of controlled anal dilatation (CAD) using a standardized maximum anal diameter. METHODS: This study included 523 patients who underwent CAD for chronic anal fissures between January 2010 and December 2014. CAD was performed under sacral epidural anesthesia. The index fingers of both hands were placed in the anus and dilated evenly in various directions. CAD was completed when the anus was dilated to the sixth scale (35 mm in diameter) using a caliber ruler. RESULTS: The mean anal scale size expanded from 3.1 to 5.8 (p<0.001). Non-healing was observed in nine patients (1.7%) at 1 month postoperatively, six of whom underwent additional CAD. The mean maximal anal resting pressure (mmHg) decreased from 90.2 to 79.7 at three months postoperatively (p<0.001). Postoperative complications were observed in 11 (2.1%) patients, of whom three patients with thrombosed hemorrhoids underwent resection. None of the patients complained of anal incontinence during the mean follow-up period of 16.6 months. The cumulative recurrence-free rates at three and five years were 87.9% and 69.2%, respectively. CONCLUSIONS: CAD is technically simple and safe and can achieve reasonable long-term outcomes. Thus, CAD appears to be the preferred procedure for patients with chronic anal fissures who do not respond to conservative treatments.