Clinical trial NCT05072821: Botulinum Toxin Type a Injection to Prevent Keloid Recurrence
Official title: Immediate Injection of Botulinum Toxin Type a After Keloid Scar Revision to Prevent Keloid Recurrence: a Prospective, Split-scar, Double-blind, Randomized Controlled Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Scar Keloid
Keywords: Keloid
Botulinum Toxin type A
Radiotherapy
Lead sponsor: National Cheng-Kung University Hospital
Sponsor class: OTHER
Collaborators: name: Tainan Hospital, Ministry of Health and Welfare
First posted: 2021-10-11
Enrollment: 28
Sex: ALL
Minimum age (years): 20
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: The prospective, split-scar, double-blind, randomized controlled study will enroll the patients who are older than 20 years with progressive keloid lesion which is symmetric. Botulinum toxin A will be injected into half of each keloid revision wound immediately after skin closure. The scars will be assessed at 1-year follow-up with Vancouver Scar Scale (VSS), Patient and Observer Scar Assessment Scale (POSAS), and the Cutometer.

Detailed description: Continuous variables will be reported as the mean ± standard deviation(SD). Each aspect of the VSS score, POSAS score, and the Cutometer parameters of each scar half between the BTA and control groups will be analyzed longitudinally using the paired t test. The interrater consistency will be evaluated using the Spearman rho. All analyses will be performed with IBM SPSS Version 23.0 (IBM Corp., Redmond, Wash.). A value of p \< 0.05 is considered to indicate statistical significance.

The sample size was calculated based on the results of the investigators' aforementioned study published in 2019. Thirty patients underwent keloid revision and then received radiation therapy based on our treatment protocol. The postoperative Vancouver Scar Scale score was 4.15 ± 1.74. If treatment could improve VSS score by 1, which was considered clinically significant, approximately 26 patients would have been necessary to provide a result with a real significance (using the same SD and considering the standard α error of 0.05 and a power of 0.8). Assuming a 20% non-compliance rate for follow-up evaluation, the sample size was increased to 32 patients.

Eligibility criteria: Inclusion Criteria:

* Adult (20 years or older)
* Progressive keloid lesion that is bilaterally symmetric, mandibular area, anterior chest or suprapubic area, for example
* At least 4 cm in length
* Repeated or uncontrolled recurrence, and unendurable symptoms with poor response to conservative modalities
* Valid written informed consent provided for surgery and trial inclusion

Exclusion Criteria:

* Allergy to botulinum toxin
* Previous botulinum toxin injection at the lesion within 6 months before enrollment
* Myasthenia gravis
* Focal infection signs
* Pregnant or breastfeeding woman

Primary outcomes:
measure: Keloid recurrence
timeFrame: One year
Secondary outcomes:
measure: Subjective symptoms
timeFrame: 3, 6, 9 and 12 months
measure: Objective symptoms
timeFrame: 3, 6, 9 and 12 months
measure: Vancouver Scar Scale
timeFrame: 6 and 12 months
measure: Scar firmness
timeFrame: 6 and 12 months
Other outcomes:
Locations:
city: Tainan
country: Taiwan
facility: National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University
Study officials:
affiliation: National Cheng-Kung University and Hospital
name: Yuan-Yu Hsueh, MD PhD
role: PRINCIPAL_INVESTIGATOR
References: