A Study of the Efficacy and Safety of Non-ablative Fractional Laser in the Treatment of Thyroidectomy Scars

Using the high-frequency skin ultrasound MD-300SⅡ, multiple-point measurements were taken in five different areas on both sides of the scar to determine the maximum and minimum values of scar echo depth and to calculate the average value of the five measurement points.The unit of measurement is millimeters.

Using the high-frequency skin ultrasound MD-300SⅡ, multiple-point measurements were taken in five different areas on both sides of the scar to determine the maximum and minimum values of scar echo width and to calculate the average value of the five measurement points.The unit of measurement is millimeters.

Using image processing software (Adobe Photoshop) to process the ultrasound images, the magic wand tool was used to select three areas of the same size on the scar. The average grayscale value of each area was read using the histogram function, and the average value of the five measurement points was calculated. The grayscale value is proportional to the echo intensity.

The Modified Vancouver Scar Scale has a maximum score of 18 and a minimum score of 0, with higher scores indicating worse outcomes.

Using the multispectral microscopic imaging device (Multi view®) to perform multiple-point measurements in three different areas on both sides of the scar, calculate the grayscale and red concentration within a specific region, and separately calculate the average values of the three measurement points. The greater the average grayscale, the lighter the skin color, and vice versa. The higher the red concentration, the more severe the skin inflammation, and vice versa.

Using the multispectral microscopic imaging device (Multi view®), identify the set of pixels with abrupt changes in brightness within the image, and employ edge detection algorithms to calculate the area of scars on both sides.

The Patient and Observer Scar Assessment Scale consists of the Patient Scar Assessment Scale and the Observer Scar Assessment Scale. Both have a maximum score of 60 and a minimum score of 6, with higher scores indicating worse outcomes.

The Manchester Scar Scale has a maximum score of 28 and a minimum score of 5, with higher scores indicating worse outcomes.

Medical Outcomes Study Health Survey Short Form-36 Item (SF-36) consists of nine dimensions and 36 items, measuring eight aspects of health: Physical Functioning (PF), Role Limitations due to Physical Health (RP), Bodily Pain (BP), General Health Perceptions (GH), Vitality (VT), Social Functioning (SF), Role Limitations due to Emotional Problems (RE), and Mental Health (MH). Additionally, there is a self-assessment of health transition (HT) compared to health status one year ago, which is not included in the subscale or total scale scoring and reflects longitudinal dynamic changes. The scoring method involves calculating the sum of weighted item scores within each of the eight subscales to obtain the raw subscale scores, which are then transformed into standard scores ranging from 0 to 100. Higher scale scores indicate better quality of life.

Two dermatologists on-site, two dermatologists via photographs, and the patient themselves answered standardized assessment questions, which included: Is there a difference between the left and right side scars? If "yes," which side is superior? The four dermatologists determined the final result using the following algorithm: If any of the four assessments indicated "no difference," or if the assessments of which half of the scar was superior did not match, the final result was determined to be "no difference."

Record and tally the frequency and severity of adverse events occurring during and after scar treatment.Incidence of adverse events = Number of cases with adverse events / Number of cases in the safety dataset × 100%.

A 3 mm punch skin biopsy was taken from the center of the scar on both the study side and the control side. The biopsies underwent dewaxing, clearing, hematoxylin and eosin (HE) staining, Masson's trichrome staining, elastic fiber staining, and immunohistochemistry for matrix metalloproteinase (MMP9). The ImageJ software was used to calculate the average scar thickness in the HE-stained sections, the average area percentage of collagen fibers in the Masson's trichrome-stained sections, the average area percentage of elastic fibers in the elastic fiber-stained sections, and the average percentage of MMP9-positive cells on both sides.