Use of botulinum toxin injections for the treatment of chronic anal fissure: Results from an American Society of Colon and Rectal Surgeons survey


Advocate Lutheran General Hospital


Background: Chronic anal fissure (CAF) is commonly treated by colorectal surgeons. Pharmacological treatment is considered first-line therapy. An alternative treatment modality is chemical sphincterotomy with injection of botulinum toxin (BT). However, there is a lack of a consensus on the BT administration procedure among colorectal surgeons.

Methods: A national survey approved by the American Society of Colon and Rectal Surgeons (ASCRS) Executive Council was sent to all members. An eight-question survey was sent via ASCRS email correspondence between December 2019 and February 2020. Questions were derived from available meta-analyses and expert opinions on BT use in CAF patients and included topics such as BT dose, injection technique, and concomitant therapies. The survey was voluntary and anonymous, and all ASCRS members were eligible to complete it. Responses were recorded and analyzed via an online survey platform.

Results: 216 ASCRS members responded to the survey and 90% inject 50-100U of BT. Most procedures are performed under MAC anesthesia (56%). A majority of respondents (64%) inject into the internal sphincter and a majority (53%) inject into 4 quadrants in the anal canal circumference. Some respondents perform concomitant manual dilatation (34%) or fissurectomy (38%). Concomitant topical muscle relaxing agents are not used uniformly among respondents.

Discussion: Injection of BT for CAF is used commonly by colorectal surgeons. There is consensus on BT dosage, administration site, technique, and the use of monitored anesthesia care.

Document Type


PubMed ID