Abstract
Chronic anal fissure (CAF) is a common disease of the anoderm treated by colorectal surgeons. Pharmacological treatment is considered first-line therapy. An alternative treatment modality is injection of botulinum toxin (BT). However, there is a lack of consensus on the administration of BT among colorectal surgeons for the treatment of CAF.
A standardised protocol has been used to write a best-evidence topic. The discussion focused on whether injection of BT is effective for chronic anal fissure. For an electronic search of the relevant literature, the databases MEDLINE, the Cochrane Library, Scopus, and the Web of Science were used.
We found 65 articles. Out of these, only eight studies were found to be appropriate to answer the question. The outcome assessed was healing of the ulcer. The best evidence shows that botulinum toxin is safe and effective in the treatment of chronic anal fissure and can be safely used as an alternative to surgery.
1. Introduction
Using a structured literature review approach, a mini-review was created that offers evidence-based solutions to common clinical concerns. This mini-review was created using the International Journal of Surgerys design [1]. The quality of the available data was insufficient to undertake a meaningful systematic review or meta-analysis, based on a previous assessment of the literature.
2. Clinical scenario
A 42-year-old female patient presented to the colorectal clinic with a history of chronic anal pain and constipation. Investigations confirmed a localised chronic anal fissure. She was previously treated with topical glyceral tri-nitrite with no benefit. The surgical team looking after the patient is debating whether botulinum toxin will be an effective treatment of choice for her based on the best evidence available.
3. Three-part question
Is botulinum toxin safe and effective non-operative management for patients with chronic anal fissure?
4. Search strategy
A. Embase 2012 to August 2022 using the OVID interface:
[botulinum toxin] AND [management] AND [chronic anal fissure] AND [non-operative] OR [conservative]
B. Medline using the PubMed interface:
[chronic anal fissure] AND [management] AND [botulinum toxin]
The results were limited to English articles and human studies.
5. Search outcome
There were 65 potentially relevant articles. After removing duplicate references and unrelated literature, fifteen papers remained for consideration. After reading all of these publications, eight were chosen as having the most convincing evidence to address the topic.
6. Result
| Author, date of publication, journal and country | Study type | Patient group | Outcomes | Follow up | Key results | Additional comments |
|---|---|---|---|---|---|---|
| Soltany et al., 2020 Journal of Family Medicine and Primary Care Iran |
Prospective case series Level V |
Total number of patients- 106 | Primary End point- Healing rate of anal fissure | Follow up- 8 weeks | Healing rate- 84.9% Mean healing time- 4.68 weeks |
Prospective study All patients received botulinum toxin treatment Healing rate was higher in females than males Single centre Short follow up period |
| Akalin et al., 2021 The American Surgeon Turkey |
Retrospective Cohort Study Level III |
Total number of patients- 44 | Primary End point- Healing rate of anal fissure | Follow up- 3 months | Group 1- Conventional method for Botulinum toxin (26): 69.23% Group 2- Endoanal ultrasound (EUAS) guided Botulinum toxin (18): 81.82% |
Retrospective study Small sample size Single centre Short follow up period |
| Amorim et al., 2017 Porto Biomedical Journal Portugal |
Retrospective Cohort Study Level III |
Total number of patients- 81 | Primary End point- Healing rate of anal fissure | Follow up- 8 weeks | Healing rate- 96.8% Non-responders- 23 (28.3%) Reinjection needed- 7 (8.6%) |
Retrospective study Single centre Small sample size Short follow up period |
| Brisinda et al., 2022 International Journal of Colorectal Disease Italy |
Retrospective Cohort Study Level III |
Total number of patients- 1003 | Primary End point- Healing rate of anal fissure | Follow up- 2 months | Healing rate- 77.7% Non-responders- 39 (3.9%) Reinjection needed- 184 (18.3%) |
Retrospective study Single centre Large sample size Short follow up period |
| Ravindran et al., 2017 Techniques in Coloproctology Australia |
Retrospective case–control study Level IV |
Total number of patients- 222 | Primary End point- Healing rate of anal fissure | Follow up- 25 months | Group 1- Low dose botulinum toxin (20-40 IU): 87% Group 2- High dose botulinum toxin (80-100 IU): 83% |
Retrospective study Single centre Large sample size In group-1, 13% of patients and in group-2, 16% of patients needed a second injection Long follow up period |
| Gulcu et al., 2021 Acta Chirurgica Belgica Turkey |
Retrospective Cohort Study Level III |
Total number of patients- 132 | Primary End point- Healing rate of anal fissure | Follow up- 24 months | Complete response- 79.5% (105) Partial response- 13% (17) Failure to respond- 3% (4) Recurrence- 4.5% (6) |
Retrospective study Single centre Small sample size Long follow up period |
| Dat et al., 2015 ANZ Journal of Surgery Australia |
Retrospective Cohort Study Level III |
Total number of patients- 101 | Primary End point- Healing rate of anal fissure | Follow up- 22 months | Complete response- 67% Partial response- 36% Failure to respond- 13% Recurrence- 32% Reinjection needed- 18.8% |
Retrospective study Single centre Small sample size Long follow up period |
| Barbeiro et al., 2017 United European Gastroenterology Journal Portugal |
Retrospective Cohort Study Level III |
Total number of patients- 88 | Primary End point- Healing rate of anal fissure | Follow up- 5 years | Complete response- 45.4% (40) Partial response- 10.2% (9) Failure to respond- 29.5% (26) Recurrence- 14.7% (13) |
Retrospective study Single centre Small sample size Long follow up period |
7. Discussion
Despite the known risk of significant morbidity, such as fecal incontinence, lateral internal sphincterotomy remains the gold standard treatment for chronic fissures [4-6]. Therefore, a search for less intrusive techniques has been ongoing, including topical nitrates and botulinum toxin injections. However, nitrates are often linked to headaches, making them less tolerable [4,7]. Botulinum toxin (BT) has been considered a potential treatment for chronic anal fissure since its discovery in 1993 [8]. Nevertheless, questions remain regarding the pharmacotherapy of anal fissure with botulinum toxin.
In our study, we explored the safety and efficacy of botulinum toxin (BT) as a treatment for chronic anal fissure. The studies included in our review aim to identify the best evidence-based practices for treating chronic anal fissure (CAF).
A prospective case series by Soltany et al. [9], involving 106 patients who received 30U of botulinum toxin, demonstrated that treating chronic anal fissures with botulinum toxin is safe, effective, and has a low complication rate. The healing rate was higher in females, patients with shorter symptom durations, and individuals with a single fissure. Akalin et al. [10] compared endo-anal ultrasound (EAUS)-guided BT injections with the conventional method in treating CAFs. This retrospective study with a small sample size of 44 patients showed that the healing rate in the EAUS group was clinically higher than in the conventional group, leading to a recommendation for a larger prospective study.
