Plain English Summary
Background and study aims
Chronic anal fissure is a tear in the anal canal that lasts for more than 2 months and doesn't respond to non-surgical treatment. This can lead to severe pain during and after bowel movements. This condition is most frequent in younger and working-age adults.
A key symptom of this condition is internal sphincter spasms (spasms of the internal muscles in the anus) and this needs to be eliminated in order to make treatment effective. This can be done surgically and non-surgically; however, both methods have issues - non-surgical treatments often lead to relapse, and surgical treatment can lead to incontinence.
This study aims to improve the treatment of anal fissures by using a new method of eliminating sphincter spasms (injection with the Botulinum toxin) to reduce the number of patients suffering with incontinence after the treatment.
Who can participate?
Patients with chronic anal fissure
What does the study involve?
Patients are assigned to either the intervention or control groups. Participants in the intervention group are given an injection of Botulinum toxin type A to eliminate internal sphincter spasm. Participants in the control group are given pneumatic balloon dilation to eliminate internal sphincter spasm, which involves a small balloon being carefully opened inside the anus.
Pneumatic balloon dilatation of anal sphincter is performed in the control group. The diameter of the anal canal is initially measured during surgery. Then the balloon of the appropriate diameter
Participants will be tested for sphincter spasms, pain and incontinence before and after the surgery.
What are the possible benefits and risks of participating?
There are no known benefits to participants taking part in this study. The possible risk for participants in the intervention group is an allergic reaction to Botulinum toxin type A. The possible risk to participants in the control group is that the dilation of the sphincter using the balloon could lead to temporary post-operative gas or incontinence.
Where is the study run from?
State Scientific Center of Coloproctology named after A.N. Ryzhykh of the Ministry of Healthcare of Russia
When is the study starting and how long is it expected to run for?
January 2017 to September 2019
Who is funding the study?
State Scientific Center of Coloproctology named after A.N. Ryzhykh of the Ministry of Health of Russia (Russia)
Who is the main contact?
Mr Eugene Zharkov
Mrs Asmat Burtseva
Dr Sergei Frolov
Open comparative randomized clinical study of the influence of Botulinum Toxin Type A injection vs. anal dilatation with inflatable balloon in patients after chronic anal fissure excision on the frequency and duration of following anal sphincter insufficiency.
There will be a reduction in the frequency and duration of anal sphincter insufficiency after Botulinum Toxin Type A injection in comparison with pneumatic balloon dilatation.
State Scientific Center of Coloproctology named after A.N. Ryzhykh of the Ministry of Health of Russia. 10/02/2018, reference number: 58
Interventional prospective randomised controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
No participant information sheet available
Chronic anal fissure
Participants were randomised using the envelope method into either the intervention or control group. Before surgery, all participants will have their pain, anal incontinence and anorectal manometry assessed.
Participants in the intervention group underwent surgical removal of the anal fissure followed by internal sphincter relaxation with the Botulinum toxin type A. Sparing surgical removal of fissure without internal sphincter incision was completed under spinal anaesthesia in surgical room at lithotomy position using electrocoagulation. After that Botulinum toxin type A was injected into the internal anal sphincter at 3 and 9 o'clock, 5 U at each point (10 U in total).
Participants in the control group underwent surgical removal of the anal fissure with pneumatic balloon dilation to relax the sphincter. Under spinal anaesthesia at lithotomy position the appropriate graduated cone was inserted in anus by rotating motions under pressure not exceeding 2 kg until the maximum contact with anal canal walls. Each cone graduation corresponded to the certain diameter of the anal canal. Thereafter, the measuring device was removed and replaced with pneumatic balloon of the appropriate diameter covered with latex and lubricated with liquid paraffin. The balloon was gradually opening under air pressure (for 1 minute) up to 0.7 bar until reaching its maximum diameter and pneumatic balloon dilatation of anal sphincter was performed for 7 minutes. Thereafter, the balloon was deflated and removed from the anus. After that the anal canal and then surgical site were treated with aqueous chlorhexidine solution. Then, sparing surgical removal of anal fissure without internal anal sphincter incision was performed using electrocoagulation via a rectal speculum.
7 days following the surgery, anorectal manometry will be performed. Anal sphincter dysfunction will be assessed 30 days after surgery. At day 60, anodermal defect healing will be assessed, along with pain, anal incontinence and anorectal manometry.
Primary outcome measure
Frequency of anal sphincter insufficiency, assessed using the Wexner score 60 days after surgery.
Secondary outcome measures
1. Frequency and structure of complications, assessed through clinical examinations at 7, 30 and 60 days after surgery
2. Pain syndrome assessed using visual analogue scale (VAS) before surgery and everyday until 60 days after surgery
3. Anorectal manometry parameters, assessed before surgery and 7 and 60 days after surgery, including:
3.1. Mean resting anal pressure
3.2. Maximum resting anal pressure
3.3. Mean squeezing anal pressure
3.4. Maximum squeezing anal pressure
4. Duration of temporary disability:
4.1. First day that patients return to work after surgery
4.2. 36-item Short Form Health Survey (SF-36) assessed the day after surgery, along with 30 and 60 days after
5. Frequency of post-operative wound epithelialization, assessed through a clinical examination of whether the wound has healed 60 days after surgery
6. Relapse rate, determined by the number of patients that return to the clinic with complaints of pain during the study period
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Aged 18-70 years old
2. Chronic anal fissure
Target number of participants
Total final enrolment
Participant exclusion criteria
1. Inflammatory disease of the colon
3. Previous surgical interventions of the anal canal
4. II-IV grade internal haemorrhoids
5. Rectal fistula
6. Severe somatic diseases at the decompensation stage
9. Intolerance or hypersensitivity to Botulinum toxin
10. Myasthenia gravis and myasthenia-like syndromes
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
State Scientific Center of Coloproctology named after A.N. Ryzhykh
Saliam Adil 2
State Scientific Centre of Coloproctology
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer-reviewed journal.
IPD sharing statement:
The datasets generated and analysed during the current study will be available upon request from Evgeny Zharkov (firstname.lastname@example.org) as an MS Access 2013 or Tibco Statistica 13 file. Data will become available after the end of the study for 3 years and will be shared with interested in scientists and publishers, for scientific analyses, after an official request by e-mail. The consent from participants is not necessary because according Russian federal law all data will be anonymised. When using data for re-analysis, reference to the source is required.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)