[Initial response to topical diltiazem can predict outcome of chronic anal fissure]

In the last few years, the medical treatment of chronic anal fissure (chemical sphincterotomy) has been introduced as a consequence of the morbidity attributed to surgical sphincterotomy. However, medical treatment has two disadvantages: moderate effectiveness (between 30% and 80%) and the need for treatment to be prolonged for more than 8 weeks.

To evaluate initial response to topical diltiazem 2% topical gel as a predictive factor in the curability of chronic anal fissure.

From February 2004 to December 200, all patients with a history of anal fissure of more than 6 weeks were included in this study. Pregnant patients and those with prior anal surgery, inflammatory bowel disease, diltiazem intolerance and problems for maintaining contact during follow-up were excluded. A magistral formula of diltiazem 2% gel was used in three applications daily for 8 weeks. Patients were followed-up clinically and pain was measured through a visual analog scale (VAS) at the end of weeks 1, 3, 6, and 8. Groups with and without response to diliazem were compared through the chi2 test, Fisher's exact test and Student's t-test. A Receiver Operating Characteristic (ROC) curve was used to evaluate the diagnostic efficacy of initial pain response to diliazem, as well as sensitivity, specificity and predictive values.

One hundred patients (70 men), with a mean age of 43 years (22-76) were analyzed. Localization was posterior in 87%, anterior in 11% and lateral in 2%. All patients had pain, 65 had bleeding, and 13 had pruritus. At the end of the 8-week treatment, cure was achieved in 62%, with morbidity of 5% (mild headache in 2%, and pruritus in 3%). No significant differences were found between the groups with and without response to diltiazem 2% in terms of age, sex, localization, bleeding, or pruritus. Notable differences were found in the VAS for pain at the end of weeks 1, 3, 6, and 8 between the two groups (p = 0.00). ROC curves established a cut-off point of 4 in the VAS at the end of week 1, with an area below the curve of 0.925 (95% CI, 0.858-0.989). The capacity of early response to diliazem to predict curability showed a sensitivity of 85.5% (95% CI, 74.7%-92.2%), a specificity of 92.1% (95% CI, 79.2%-97.3%), a positive predictive value of 94.6% (95% CI, 85.4%-98.2%), and a negative predictive value of 79.5% (95% CI, 65.5%-88.8%). Among patients who showed no response to diltiazem by the end of week 1, cure was achieved in only 9% at 8 weeks. In contrast, among those with a favorable response in the first week, cure was achieved in 94.6%.

Lack of response to topical diltiazem 2% gel at the end of the first week reliably predicts failure of medical treatment for chronic anal fissure, obviating the need to prolong treatment for 8 weeks.