title: Botulinum toxin vs glyceryltrinitrate for the medical management of chronic anal fissure: a meta-analysis.
abstract: OBJECTIVE
  The objective of this review was to analyse systematically the prospective randomized controlled trials on the effectiveness of botulinum toxin (BTX) and glyceryltrinitrate (GTN) for the pharmacological management of chronic anal fissure (CAF).
  
  
  METHODS
  A systematic review of the literature was undertaken. Prospective randomized controlled trials on the effectiveness of BTX and GTN for the management of CAF were selected according to specific criteria and analysed to generate summative data.
  
  
  RESULTS
  Six studies encompassing 355 patients with CAF were retrieved from electronic databases. Only three randomized controlled trials on 180 patients qualified for the meta-analysis according to inclusion criteria. There were 90 patients in BTX and 90 in the GTN group. BTX and GTN were equally effective in healing/improving the CAF. There was no statistically significant difference between the two pharmacotherapies [RR 1.29 (0.98-1.70) 95% CI, z = -1.83, P = 1.93, Fig. 1]. However, there was statistically significant heterogeneity among the trials (Q = 4.03, df = 1, P = 0.042). On fixed effect model, GTN was associated with higher incidence of total side effects [fixed effect model RR 0.14 (0.05-0.40) 95% CI, z = -3.71, P = 0.0002] and headache [RR 0.07 (0.02-0.20) 95% CI, z = -5.05, P = 0.0007] among patients of CAF.
  
  
  CONCLUSIONS
  Botulinum toxin is as effective as GTN for the management of CAF but it is associated with a lower complication rate. BTX can be recommended as a first-line therapy for chemical sphincterotomy in patients of CAF. However, a major and multi-centre randomized controlled trial is required to support this treatment approach in order to establish stronger evidence.
authors.affiliation: Department of Colorectal Surgery, Worthing Hospital, Worthing, West Sussex, UK. surgeon1wrh@hotmail.com
authors.forename: M S
authors.initials: MS
authors.lastname: Sajid
authors.forename: B
authors.initials: B
authors.lastname: Vijaynagar
authors.forename: M
authors.initials: M
authors.lastname: Desai
authors.forename: E
authors.initials: E
authors.lastname: Cheek
authors.forename: M K
authors.initials: MK
authors.lastname: Baig
mesh_terms: D018726:Anti-Dyskinesia Agents / Q000627:therapeutic use*; D001905:Botulinum Toxins / Q000627:therapeutic use*; D002908:Chronic Disease; D005260:Female; D005401:Fissure in Ano / Q000188:drug therapy*; D006801:Humans; D008297:Male; D005996:Nitroglycerin / Q000627:therapeutic use*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D014665:Vasodilator Agents / Q000627:therapeutic use*
chemical_list: D018726:Anti-Dyskinesia Agents; D014665:Vasodilator Agents; D001905:Botulinum Toxins; D005996:Nitroglycerin