Effectiveness of 0.3 % nifedipine gel combined with 2.0 % lidocaine and BTA 80 U in treatment of chronic anal fissure. Pilot randomized study. Preliminary results

AIM: to improve the results of chronic anal fissure treatment. PATIENTS AND METHODS: the study included 22 patients randomized by random numbers generation method into 2 groups. Eleven patients were included in main group and were treated with 0.3 % nifedipine + 2.0 % lidocaine gel, 11 patients of the control group received injections of botulinum toxin A into the internal anal sphincter at a dose of 80 U (BTA 80). RESULTS: by day 30, there was a decrease of maximal resting pressure in anal canal (MRPAC) in both the main and control groups [p = 0.015 and p = 0.004, respectively] and the average resting pressure in anal canal (ARPAC) [p = 0.01 and p = 0.02, respectively]. There was no difference between the groups in pain severity both after stool and during the day (p = 0.5 and p = 0.6, respectively). On day 60, the defect was epithelized in 6/11 (54.6 %) patients of the study group and in 9/11 (81.8 %) patients of the BTA 80 group [p = 0.36], respectively. The reason of treatment failure in 4/11 (36.4 %) patients of the main group and 2/11 (18.2 %) patients of the control group was a preserved internal sphincter spasm. It was found that these patients used a lower amount of the drug product — 2.2 (1.8; 2.5) mg/day compared to 2.4 (1.9; 2.7) mg/day in other patients. On the day 30 after surgical treatment, complaints about gas incontinence were registered in 1/11 (9.1 %) patients of the main group and 1/11 (9.1 %) patients of the control group [p = 1]. Such a complication as external hemorrhoid thrombosis occurred only in 1/11 (9.1 %) patients in the BTA 80 group [p = 0.87]. CONCLUSION: the study results show that gel containing 0.3 % nifedipine and 2 % lidocaine produces an effect on the tone of the internal sphincter comparable to BTA. However, the lack of accurate dosage of the drug product and/or low patient compliance reduce the effectiveness of treatment and make the use of BTA preferable for medical relaxation of the internal sphincter.