Comparative Efficacy of Topical Metronidazole and Glyceryl Trinitrate Versus Topical Glyceryl Trinitrate Alone in the Treatment of Acute Anal Fissure: A Randomized Clinical Trial

Abstract

Background and objective An anal fissure is a longitudinal, oval lesion in the anal canal. In over 90% of instances, the anal fissures are located posterior to the midline and produce discomfort upon defecation and/or bleeding owing to spasms of the internal anal sphincter that leads to ischemia. This research aimed to determine if topical metronidazole treatment when combined with glyceryl trinitrate 0.2% (GTN), is more successful than GTN alone in reducing the time for an acute anal fissure to heal. Material and methods This study was a single-blinded, randomized controlled trial conducted at the DHQ Hospital Okara from January 2022 to August 2022. Patients of both genders, aged 18 to 70 years, with acute anal fissures, were included. One hundred forty patients who satisfied the inclusion criteria were randomized through the lottery technique and were divided into two groups (70 in each group). Group A contained patients who got metronidazole combination with GTN, while in Group B, patients treated with GTN alone without metronidazole. The primary endpoint was fissure healing, confirmed as finding a scar where the fissure was. While the secondary endpoint was maximum pain on defecation assessed by the Visual Analogue Scale (VAS). Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) v24. Chi-Square and Fisher's Exact tests were done for statistical analysis, and p < 0.05 was considered significant. Results Three patients lost the follow-up. Out of the remaining 137, 70 (51.1%) patients were male. The patient's ages ranged from 22 to 68 years, with a mean age of 39.18 ± 11.52. One hundred twenty six (92%) complained of pain on defecation with a mean VAS of 6.01 ± 2.35. 80 (58.4%) patients complained of perianal itching, while 25 (18.2%) patients complained of bleeding on defecation. On week 1 follow-up, in group A out of 69 patients, 27 (39.1%) had complete healing, 38 (55.1%) had partial healing, while in group B out of 68 patients, one (1.4%) had complete healing, 43 (63.2%) had partial healing (p = < 0.001, significant). On week 3 follow-up, in group A out of 69 patients, 47 (68.1%) had complete healing, and 22 (31.8%) had partial healing, while in group B out of 68 patients, 16 (23.5%) had complete healing, 49 (72%) had partial healing (p = < 0.001, significant). Mean VAS score of group A was 0.61 ± 1.38 while that of group B was 2.57 ± 2.50 (p = < 0.001, significant). Conclusion Using topical metronidazole as an addition to standard therapy may reduce the chronicity of acute anal fissures and prevent surgical treatments with high rates of complications.

Keywords: anal fissure; colorectal disease; glyceryl trinitrate; metronidazole; pr bleeding; proctological surgery.

Figure 1. Etiological factors of anal fissure