title: Glyceryl trinitrate for chronic anal fissure--healing or headache? Results of a multicenter, randomized, placebo-controled, double-blind trial.
abstract: OBJECTIVE
  Internal anal sphincterotomy for treating chronic anal fissure can irreversibly damage anal continence. Reversible chemical sphincterotomy may be achieved by anal application of glyceryl trinitrate ointment (nitric oxide donor), which has been reported to heal the majority of patients with anal fissure by inducing sphincter relaxation and improving anodermal blood flow. This trial aimed to further clarify the role of glyceryl trinitrate in the treatment of chronic anal fissure.
  
  
  METHODS
  A total of 132 consecutive patients from nine centers were randomly assigned to receive 0.2 percent glyceryl trinitrate ointment or placebo twice daily for at least four weeks. The severity of pain and maximum anal resting pressure were measured before and after one week of treatment. Anodermal blood flow was measured before and after application of glyceryl trinitrate or placebo in ten patients.
  
  
  RESULTS
  The study was completed by 119 patients (59 glyceryl trinitrate and 60 placebo), matched for gender, age, duration of symptoms, duration of treatment, site of fissure, previous attempts to treat, pain score, and maximum anal resting pressure. Twenty-nine patients (49.2 percent) healed after glyceryl trinitrate and 31 patients (51.7 percent) healed after placebo (P = not significant). Pain score fell significantly in both groups, in addition to maximum anal resting pressure. Anodermal blood flow improved significantly in seven patients receiving glyceryl trinitrate, but not in the three receiving placebo. Twenty-three patients (33.8 percent) experienced headache and 4 (5.9 percent), orthostatic hypotension after glyceryl trinitrate.
  
  
  CONCLUSIONS
  This trial fails to demonstrate any superiority of topical 0.2 percent glyceryl trinitrate treatment vs. a placebo, although the effects of glyceryl trinitrate on anodermal blood flow and sphincter pressure are confirmed. This finding, together with the high incidence of side-effects, should discourage the use of this treatment as a substitute for surgery in chronic anal fissure.
authors.affiliation: Dipartimento di Emergenza e Trapianti d'Organo, Università di Bari, Italy.
authors.forename: D F
authors.initials: DF
authors.lastname: Altomare
authors.forename: M
authors.initials: M
authors.lastname: Rinaldi
authors.forename: G
authors.initials: G
authors.lastname: Milito
authors.forename: F
authors.initials: F
authors.lastname: Arcanà
authors.forename: F
authors.initials: F
authors.lastname: Spinelli
authors.forename: N
authors.initials: N
authors.lastname: Nardelli
authors.forename: D
authors.initials: D
authors.lastname: Scardigno
authors.forename: A
authors.initials: A
authors.lastname: Pulvirenti-D'Urso
authors.forename: C
authors.initials: C
authors.lastname: Bottini
authors.forename: M
authors.initials: M
authors.lastname: Pescatori
authors.forename: R
authors.initials: R
authors.lastname: Lovreglio
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000098:blood supply; D001783:Blood Flow Velocity / Q000187:drug effects; D002908:Chronic Disease; D004311:Double-Blind Method; D005260:Female; D005401:Fissure in Ano / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D006261:Headache / Q000139:chemically induced*; D006801:Humans; D007024:Hypotension, Orthostatic / Q000139:chemically induced; D017078:Laser-Doppler Flowmetry; D008297:Male; D008365:Manometry; D005996:Nitroglycerin / Q000009:adverse effects / Q000627:therapeutic use*; D009824:Ointments; D010146:Pain / Q000209:etiology / Q000503:physiopathology; D010147:Pain Measurement; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000009:adverse effects / Q000627:therapeutic use*; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D009824:Ointments; D014665:Vasodilator Agents; D005996:Nitroglycerin