Effect of Glyceryl Trinitrate Ointment on Pain Control After Hemorrhoidectomy: A Meta-analysis of Randomized Controlled Trials.

Abstract

Hemorrhoidectomy is associated with postoperative pain and prolonged wound healing. Glyceryl trinitrate has been shown to decrease muscle spasm and increase anodermal blood flow. A meta-analysis of randomized controlled trials was conducted to evaluate the efficacy of topical glyceryl trinitrate application in pain relief after hemorrhoidectomy. PubMed, EMBASE, Cochrane Library, Scopus, and ClinicalTrials.gov registries were searched for studies published before August 2015. Individual effect sizes were standardized, and a meta-analysis was conducted to calculate a pooled effect size using random effects models. Pain was assessed using a visual analog scale on days 1, 3, 7, and 14 after operation. Secondary outcomes included time taken to resume routine activities, wound healing at 3 weeks after operation, complication, and headache incidence. A total of 12 trials with 1095 patients were reviewed. Significant pain reduction was observed on days 1, 3, 7, and 14 after hemorrhoidectomy in the glyceryl trinitrate groups. Glyceryl trinitrate-treated patients appeared to resume routine activities earlier than those in the control group (weight mean difference -7.52; 95% confidence interval: 16.13-1.08). The wound healing rates 3 weeks after operation were significant higher in the glyceryl trinitrate-treated groups than in the control group (risk ratio 1.79; 95% confidence interval: 1.38-2.33). However, the incidence of headache significantly increased in the glyceryl trinitrate group (risk ratio 3.68; 95% confidence interval: 1.62-8.34). Topical application of glyceryl trinitrate effectively relieves pain and promotes wound healing after hemorrhoidectomy; however, the substantial headache incidence may limit extensive application.