Botulinum Toxin Type a Injection to Prevent Keloid Recurrence

National Cheng-Kung University

Status and phase: Completed; Phase 4

Conditions: Scar Keloid

Treatments: Drug: Botulinum Toxin Type A Injection [Botox]; Drug: 0.9% Sodium Chloride Injection

Study type: Interventional

Funder types: Other

Identifiers

NCT05072821

MOHW109-TDU-B-211-114003

Details and patient eligibility

About

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.

Full 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.

Enrollment: 28 patients

Sex: All

Ages: 20+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

---

28 participants in 2 patient groups, including a placebo group

Botulinum Toxin type A injection side

Experimental group

Description:

The Botulinum Toxin type A will be injected into the dermal layer before skin closure in keloid excision surgery. The concentration of Botulinum Toxin type A is 100 units in 2 mL and dosage is 8 units/cm. The maximal dose is 100 units for each participant.

Treatment:

Drug: Botulinum Toxin Type A Injection [Botox]

0.9% saline injection side

Placebo Comparator group

Description:

The 0.9% saline will be injected into the dermal layer before skin closure in keloid excision surgery. The dosage is 0.16 mL/cm.

Treatment:

Drug: 0.9% Sodium Chloride Injection