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NCT Number: NCT05072821

Botulinum Toxin Type a Injection to Prevent Keloid Recurrence

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.

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Key information

Conditions

Scar Keloid Cicatrix Collagen Diseases Connective Tissue Diseases Fibrosis Keloid Pathologic Processes Pathological Conditions, Signs and Symptoms Skin and Connective Tissue Diseases

Age range

20 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University

Tainan, Taiwan

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Botulinum Toxin Type A Injection [Botox]

Drug

After the whole surgical procedures of keloid revision are done, the participants will receive Botulinum Toxin type A (BTA) injection. The investigators split the scar into the right side and the left side. BTA and 0.9% saline, respectively, are used for the two arms of the study. Vials containing 100 units of BTA (BotoxⓇ, Allergan) are mixed with 2mL 0.9% injectable saline. The injection depth will be the intradermal layer. Injections will be performed with a 30-gauge needle and 1 mL syringe. Just before skin closure, the entire scar was treated, with sides randomized to receive treatment with either BTA or 0.9% normal saline. The dosage is 8 units / cm based on aforementioned studies. The maximal dose won't exceed 100 units.

0.9% sodium chloride injection

Drug

After the whole surgical procedures of keloid revision are done, the participants will receive 0.9% saline injection. The investigators split the scar into the right side and the left side. BTA and 0.9% saline, respectively, are used for the two arms of the study. Only 0.9% saline is injected on the control side. The injection depth will be the intradermal layer. Injections will be performed with a 30-gauge needle and 1 mL syringe. Just before skin closure, the entire scar was injected, with sides randomized to receive treatment with either BTA or 0.9% normal saline. The dosage is 0.16 mL / cm.

Primary outcomes

  1. Keloid recurrence

    Time frame: One year

    The recurrence of keloid will be determined by clinical examination evaluated by a dermatologist.

Secondary outcomes

  1. Subjective symptoms

    Time frame: 3, 6, 9 and 12 months

    The subjective symptoms will be measured by the Patient Scale of the Patient and Observer Scar Assessment Scale. The Patient Scale consists six items and scores from 1 to 10 for each items. The score of 1 means much alike the normal skin and the score of 10 means worst imaginable scar.

  2. Objective symptoms

    Time frame: 3, 6, 9 and 12 months

    The subjective symptoms will be measured by the Observer Scale of the Patient and Observer Scar Assessment Scale. The Observer Scale consists six items and scores from 1 to 10 for each items. The score of 1 means much alike the normal skin and the score of 10 means worst imaginable scar.

  3. Vancouver Scar Scale

    Time frame: 6 and 12 months

    One dermatologist will evaluate the scar with the Vancouver Scar Scale. The Vancouver Scar Scale consists 4 items. The minimum score is 0, which means the scar is much alike normal skin. The maximal score is 13, which means purple, hyperpigmentation, contracture and elevated scar.

  4. Scar firmness

    Time frame: 6 and 12 months

    The scar firmness is determined by the Cutometer parameter R0. R0 is maximum amplitude of the curve (the total elongation). The larger R0 is, the softer the scar is.

Sponsors and collaborators

Lead sponsor

National Cheng-Kung University Hospital

Other

Collaborators

  • Tainan Hospital, Ministry of Health and Welfare

Registry information

Official study 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

Important dates

Study start
2020
Primary completion
2024
Study completion
2024
First posted
Oct 11, 2021
Registry last updated
Nov 7, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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