Chronic Anal FissureNCT07543315
Low Versus High Dose OnabotulinumtoxinA for Chronic Anal Fissure
An observational study of Chronic Anal Fissure, run by Tanta University at 1 site in Egypt.
Trial summary
This prospective single-center cohort study describes short-term and one-year clinical outcomes of two routine doses of OnabotulinumtoxinA (20 units versus 50 units) for chronic anal fissure refractory to conservative therapy. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Chronic Anal Fissure
- What is being tested?
- OnabotulinumtoxinA
- How many people
- 150 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Aug 2023to 30 Aug 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adults aged 18-70 years with chronic anal fissure refractory to conservative therapy attending the outpatient colorectal surgery clinic of Tanta University Hospitals, Egypt.
Who may be able to join
- Age 18-70 years
- Chronic anal fissure persisting for at least 8 weeks
- Refractory to a standardized 8-week conservative protocol (dietary fiber supplementation, sitz baths and topical vasodilator therapy)
Who cannot join
- Atypical, secondary or complicated fissure (e.g., Crohn's disease, associated fistula or abscess)
- Previous anorectal surgery
- Pregnancy or breastfeeding
- Local infection at the injection site
- Neuromuscular disorders
- Hypersensitivity or other contraindication to botulinum toxin
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Short-Term Clinical Outcomes of Two Routine Botulinum Toxin Regimens (20 Units Versus 50 Units of OnabotulinumtoxinA) for Chronic Anal Fissure: A One-Year Prospective Cohort Study
This prospective single-center cohort study describes short-term and one-year clinical outcomes of two routine doses of OnabotulinumtoxinA (20 units versus 50 units) for chronic anal fissure refractory to conservative therapy. The dose was determined by each surgical unit's established routine practice and was not assigned by the investigators. Both doses were given as bilateral internal sphincter injections at the 3 and 9 o'clock positions in an equal 1-mL volume. The primary outcome is disease-specific quality of life (HEMO-FISS-QoL) at 1 month. Patients are followed for 12 months for pain, healing, continence, recurrence and need for lateral internal sphincterotomy.
Read the detailed description
Setting: Outpatient colorectal surgery clinic, Tanta University Hospitals, Egypt. Two surgical units in the department operated on alternating days and followed different routine OnabotulinumtoxinA regimens: one unit routinely used 20 U and the other 50 U. Because patients presented on any day without regard to which unit was on duty, the dose received depended on the unit on duty on the day of presentation and was not selected on the basis of individual patient characteristics.
Technique: A 100-U vial was reconstituted with 5 mL (20 U/mL) or 2 mL (50 U/mL) of preservative-free 0.9% saline. 0.5 mL was injected into the internal anal sphincter at each of the 3 and 9 o'clock positions (10 U + 10 U, or 25 U + 25 U), in the office without anesthesia.
Follow-up: weekly during month 1, monthly to month 3, then every 3 months to month 12. No further topical therapy was used after injection.
Registration: This study was registered retrospectively after enrollment was complete.
Ethics approval: Research Ethics Committee, Faculty of Medicine, Tanta University (approval code 36264PR284/7/23).
- Conditions
- Chronic Anal Fissure
- Being tested
- OnabotulinumtoxinA
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OnabotulinumtoxinADrug
OnabotulinumtoxinA, 100-U vial reconstituted with preservative-free 0.9% saline, given as 1 mL into the internal anal sphincter (0.5 mL at 3 o'clock and 0.5 mL at 9 o'clock) without anesthesia. 20-U cohort: 20 U/mL (10 U per site). 50-U cohort: 50 U/mL (25 U per site). Dose determined by the treating unit's routine practice.
| Study group | Role | What they receive |
|---|---|---|
| 20-U Cohort | Patients treated in the surgical unit that routinely uses 20 units of OnabotulinumtoxinA: 10 U into the internal anal sphincter at 3 o'clock and 10 U at 9 o'clock (1 mL total volume). Receives: Drug: OnabotulinumtoxinA | |
| 50-U Cohort | Patients treated in the surgical unit that routinely uses 50 units of OnabotulinumtoxinA: 25 U into the internal anal sphincter at 3 o'clock and 25 U at 9 o'clock (1 mL total volume). Receives: Drug: OnabotulinumtoxinA |
What is being measured
The primary outcome is the main question the study is designed to answer.
Disease-specific quality of life (HEMO-FISS-QoL total score)
Total score of the Hemorrhoidal Disease and Anal Fissure Quality of Life (HEMO-FISS-QoL) questionnaire, transformed to a 0-100 scale (0 = no burden, 100 = maximum burden; higher scores indicate worse quality of life). Compared between the 20-U and 50-U cohorts.
Measured: 1 month after injection
Secondary outcomes (12)
Pain intensity at 1 month (visual analogue scale)
Key secondary outcome. Pain measured on a 0-10 visual analogue scale (0 = no pain, 10 = worst imaginable pain; higher scores indicate worse pain). Compared between the 20-U and 50-U cohorts.
Measured: 1 month after injection
Pain intensity during follow-up (visual analogue scale)
Pain on a 0-10 visual analogue scale (0 = no pain, 10 = worst imaginable pain; higher scores indicate worse pain).
Measured: Baseline, 1 week, 3 months, 6 months and 12 months after injection
Disease-specific quality of life during follow-up (HEMO-FISS-QoL total score)
HEMO-FISS-QoL total score transformed to 0-100 (higher scores indicate worse quality of life).
Measured: 3, 6 and 12 months after injection
Complete fissure healing
Proportion of participants with complete epithelialization of the fissure on clinical examination.
Measured: 8 weeks after injection
Time to complete healing
Time in weeks from injection to complete fissure healing on clinical examination, among participants who healed.
Measured: Up to 8 weeks after injection
Fecal continence (Wexner incontinence score)
Wexner (Cleveland Clinic) incontinence score, range 0-20 (0 = perfect continence, 20 = complete incontinence; higher scores indicate worse continence).
Measured: Baseline, 1 week, 1 month, 3 months, 6 months and 12 months after injection
Transient flatus incontinence
Proportion of participants reporting new, temporary incontinence to flatus after injection.
Measured: Up to 12 months after injection
Fissure recurrence after initial healing
Proportion of initially healed participants with clinical recurrence of the fissure.
Measured: Up to 12 months after injection
Lateral internal sphincterotomy
Proportion of participants who underwent lateral internal sphincterotomy for primary healing failure or recurrence.
Measured: Up to 12 months after injection
Persistence of bleeding
Proportion of participants still reporting rectal bleeding at each early visit.
Measured: 1, 2 and 3 weeks, 1 month and 3 months after injection
Persistence of clinically evident pain
Proportion of participants still reporting clinically evident pain as a symptom complaint (recorded as present or absent, distinct from the VAS score) at each early visit.
Measured: 1, 2 and 3 weeks, 1 month and 3 months after injection
Return to daily activity
Time to return to normal daily activity after injection, categorized as immediately, after 2 days, or after 4 days.
Measured: First week after injection
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Apr 2026
- Study start1 Aug 2023
- Primary completion30 Aug 2025
- Study completion30 Aug 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chronic Anal FissureStudies of the same condition, open and under way.
- More trials run by Tanta UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 150 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tanta University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sherehan Moeness ElShishtawy, Tanta University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07543315
- Sponsor's protocol ID
- 36264PR284/7/23
- Status last verified
- Aug 2026
- First submitted
- 14 Apr 2026
- Last updated
- 28 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Short-Term Clinical Outcomes of Two Routine Botulinum Toxin Regimens (20 Units Versus 50 Units of OnabotulinumtoxinA) for Chronic Anal Fissure: A One-Year Prospective Cohort Study
- ClinicalTrials.gov ID
- NCT07543315
- Acronym / sponsor ID
- 36264PR284/7/23
- Conditions
- Chronic Anal Fissure
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 150 participants (actual)
- Lead sponsor
- Tanta UniversityUniversity, hospital or other
- Study start
- 1 Aug 2023 (actual)
- Primary completion
- 30 Aug 2025 (actual)
- Study completion
- 30 Aug 2026 (actual)
- First posted
- 21 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective single-center cohort study describes short-term and one-year clinical outcomes of two routine doses of OnabotulinumtoxinA (20 units versus 50 units) for chronic anal fissure refractory to conservative therapy. The dose was determined by each surgical unit's established routine practice and was not assigned by the investigators. Both doses were given as bilateral internal sphincter injections at the 3 and 9 o'clock positions in an equal 1-mL volume. The primary outcome is disease-specific quality of life (HEMO-FISS-QoL) at 1 month. Patients are followed for 12 months for pain, healing, continence, recurrence and need for lateral internal sphincterotomy.
Detailed description
Setting: Outpatient colorectal surgery clinic, Tanta University Hospitals, Egypt. Two surgical units in the department operated on alternating days and followed different routine OnabotulinumtoxinA regimens: one unit routinely used 20 U and the other 50 U. Because patients presented on any day without regard to which unit was on duty, the dose received depended on the unit on duty on the day of presentation and was not selected on the basis of individual patient characteristics.
Technique: A 100-U vial was reconstituted with 5 mL (20 U/mL) or 2 mL (50 U/mL) of preservative-free 0.9% saline. 0.5 mL was injected into the internal anal sphincter at each of the 3 and 9 o'clock positions (10 U + 10 U, or 25 U + 25 U), in the office without anesthesia.
Follow-up: weekly during month 1, monthly to month 3, then every 3 months to month 12. No further topical therapy was used after injection.
Registration: This study was registered retrospectively after enrollment was complete.
Ethics approval: Research Ethics Committee, Faculty of Medicine, Tanta University (approval code 36264PR284/7/23).
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 20-U Cohort | – | Drug: OnabotulinumtoxinAPatients treated in the surgical unit that routinely uses 20 units of OnabotulinumtoxinA: 10 U into the internal anal sphincter at 3 o'clock and 10 U at 9 o'clock (1 mL total volume). |
| 50-U Cohort | – | Drug: OnabotulinumtoxinAPatients treated in the surgical unit that routinely uses 50 units of OnabotulinumtoxinA: 25 U into the internal anal sphincter at 3 o'clock and 25 U at 9 o'clock (1 mL total volume). |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults aged 18-70 years with chronic anal fissure refractory to conservative therapy attending the outpatient colorectal surgery clinic of Tanta University Hospitals, Egypt.
Key inclusion criteria (3 listed)
- Age 18-70 years
- Chronic anal fissure persisting for at least 8 weeks
- Refractory to a standardized 8-week conservative protocol (dietary fiber supplementation, sitz baths and topical vasodilator therapy)
Key exclusion criteria (6 listed)
- Atypical, secondary or complicated fissure (e.g., Crohn's disease, associated fistula or abscess)
- Previous anorectal surgery
- Pregnancy or breastfeeding
- Local infection at the injection site
- Neuromuscular disorders
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| OnabotulinumtoxinAOnabotulinumtoxinA, 100-U vial reconstituted with preservative-free 0.9% saline, given as 1 mL into the internal anal sphincter (0.5 mL at 3 o'clock and 0.5 mL at 9 o'clock) without anesthesia. 20-U cohort: 20 U/mL (10 U per site). 50-U cohort: 50 U/mL (25 U per site). Dose determined by the treating unit's routine practice. | Drug | 20-U Cohort, 50-U Cohort |
Primary outcome
Disease-specific quality of life (HEMO-FISS-QoL total score)
Time frame: 1 month after injection
Total score of the Hemorrhoidal Disease and Anal Fissure Quality of Life (HEMO-FISS-QoL) questionnaire, transformed to a 0-100 scale (0 = no burden, 100 = maximum burden; higher scores indicate worse quality of life). Compared between the 20-U and 50-U cohorts.
12 secondary outcomes
Pain intensity at 1 month (visual analogue scale)
Time frame: 1 month after injection
Pain intensity during follow-up (visual analogue scale)
Time frame: Baseline, 1 week, 3 months, 6 months and 12 months after injection
Disease-specific quality of life during follow-up (HEMO-FISS-QoL total score)
Time frame: 3, 6 and 12 months after injection
Complete fissure healing
Time frame: 8 weeks after injection
Time to complete healing
Time frame: Up to 8 weeks after injection
Fecal continence (Wexner incontinence score)
Time frame: Baseline, 1 week, 1 month, 3 months, 6 months and 12 months after injection
Transient flatus incontinence
Time frame: Up to 12 months after injection
Fissure recurrence after initial healing
Time frame: Up to 12 months after injection
Lateral internal sphincterotomy
Time frame: Up to 12 months after injection
Persistence of bleeding
Time frame: 1, 2 and 3 weeks, 1 month and 3 months after injection
Persistence of clinically evident pain
Time frame: 1, 2 and 3 weeks, 1 month and 3 months after injection
Return to daily activity
Time frame: First week after injection
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Chronic Anal Fissure, run by Tanta University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Disease-specific quality of life (HEMO-FISS-QoL total score) (time frame: 1 month after injection). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2026.