Introduction & Objective: Chronic anal fissure is one of the most common anorectal diseases. Most patients recovered by conservative treatments. But the disease is chronic if clinical manifestations lasts more than six weeks. Sphincterotomy is known as the treatment of choice for chronic anal fissure, although it is associated with long-term potential complications. Flatus and fecal incontinence, infection, and persistent pain are uncomfortable side effects that may occur in 0.35 of patients undergoing sphincterotomy.
Materials & Methods: In a randomized clinical trial, 86 patients with chronic anal fissure were randomly divided into two groups. Eligible patients were divided into two groups: the first group were treated with 60 unit of Dysport injected into the internal anal sphincter, and the second group underwent lateral internal sphincterotomy. Then the rate of recovery and postoperative complications, such as pain, bleeding and recurrence or other complications were compared during the 3-month follow-up.
Results: Two weeks after the treatment, the recovery rate was 100% (86 patients), from which 19
patients (22.09%) had partial improvement and 67 (77.91%) had complete recovery. The complete
recovery rate in the two study groups of PLIS and disport injection were (36 cases) 83.72% and (31 cases)
72.09% respectively. The relative recovery rate in the two groups, were 16.28% and 27.91%, respectively
(P=0.194). In 3 months follow-up after the treatment, the complete recovery rate in the two groups of PLIS
and disport injection groups were (36 cases) 83.72% and (31 cases) 72.09% respectively. The relative
recovery rate in the two groups were respectively (4 cases) 9.3% and (3 cases) 6.98%. The recurrence rate
between the two groups of PLIS and disport injection groups were respectively (3 cases) 6.98% and (9
cases) 20.93%. The difference between the recovery rate and recurrence rate, 3 months after the treatment
in both groups was not significant (P=0.059). The mean duration of pain for the disport injection and PLIS
were respectively 6.77±2.02 and 11.98±2.48 days, (P<0.001). The mean duration of the patient to return to
work in disport injection and PLIS groups were calculated to be respectively 1.51±0.56 and 9.21±2.66
(P<0.001).
Conclusions: According to the findings of the present study, and similar treatment results, in the two groups of open sphincterotomy and botulinum toxin injection, considering the short duration of pain and return to work after the injection of botulinum, the latter method can be recommended as an alternative in the treatment of chronic anal fissure. Definitive conclusions require further studies in the future.