Comparison of topical glyceryl trinitrate with diltiazem ointment for treatment of chronic anal fissure. A randomized clinical trial. Ann. Ital. Chir., 80, 5, 2009 379 Ann. Ital. Chir., 2009; 80: 379-383 Background Anal fissure is a linear tear in the mucosa of the anal canal normally extending distally from the dentate line to the anal verge. An acute tear in the mucosa is anal- ogous to a ‘split lip’ of the anus; if this fails to heal it progresses to a chronic anal fissure 1 . Although there is no defined time period distinguishing acute from chron- ic fissures, some authors suggest a chronic fissure should be present for at least 6–8 week 2,3 . However, the stan- dard treatment for chronic anal fissure has been lateral sphincterotomy which has a high success rate 4 but can cause significant short- and long-term morbidity with incontinence rates of up to 30 per cent 5 . In recent years, various medical therapies have been used for the treatment of chronic anal fissure with a view to reducing the resting anal canal pressure and improving the vascularity of internal sphincter muscle. The agents that have been used are glycerol trinitrate ointment (GTN) 6,7 , nifedipine 8,9 , botulinum toxin 6 , bethanechol 10 and diltiazem hydrochloride (DTZ) 10,11 . GTN oint- ment produces a temporary ‘chemical sphincterotomy’, with healing rates of 83–86% in early studies 12,13 but only 30-46% in more recent publications 14-17 . Up to 80% of patients 15 develop headaches during treatment Pervenuto in Redazione Maggio 2009. Accettato per la pubblicazione Giugno 2009. For correspondence: Mohsen Mahmoudieh, Department of Surgery, Alzahra Hospital, Isfahan, Iran. (e-mail: mahmoudieh@med.mui.ac.ir). Behnam Sanei*, Mohsen Mahmoodieh*, Hassan Masoudpour** Department of General Surgery, Alzahra Hospital, Isfahan, Iran *Assistant Professor of General Surgery **Resident of General Surgery Comparison of topical glyceryl trinitrate with dialtazem ointment for treatment of chronic anal fissure. A randomized clinical trial BACKGROUND: The aim of this study was to compare the effect of topical glycerol trinitrate ointment (GTN) with topical diltiazem hydrochloride ointment (DTZ) in the treatment of chronic anal fissure. METHOD: Prospectively, 102 patients were treated randomly with either GTN ointment (0.2%) or DTZ ointment (2%) couple of times daily for 12 weeks. RESULTS: Forty-five patients (88.2%) in group DTZ and 36 patients (70.6%) in group GTZ had reduction of symp- toms. The decrease in the symptoms for group DTZ were significantly more than that for group GTN (P= 0.02). Mean time of symptom reduction was 2.44±0.30 in group DTZ and 2.50±0.28 weeks in group GTN without significant differences between two groups (P>0.05). Complete relieving of symptoms was observed in 72.5%, 54.9% patients in groups DTZ and GTN, respectively. The frequency of complete relieving of symptoms between two groups was not sig- nificant (P>0.05). Complete remission of anal fissure was occurred in 66.7% patients in group DTZ and 54.9% patients in group GTN, which was no different, significantly. Mean time taken for fissure healing in GTN group was dramat- ically less than DTZ group (P=0.001). Finally, 33.3% of patients in DTZ group and 45.1% of patients in GTN group was operated. The need for operation was not significant between two groups (P>0.05). CONCLUSION: Both DTZ and GTN are equally effective and can be the preferred first-line treatment of chronic anal fissure a. However, GTN is associated with a higher rate of headache, and it should be replaced by DTZ. KEY WORDS: Anal fissure, Lateral sphyncterotomy.