Scars can be caused by physical trauma, surgical incisions, burn injuries and even acne. Deep cutaneous injuries induce pathological scars. Other factors, such as mechanical loading, bacterial colonization are potential factors thought to underlie human hypertrophic and keloid scar formation or contractures. The effect may include functional impairment and aesthetic disadvantages.
Various non-invasive mechanical interventions of physical scar management (e.g. extracorporeal shock wave therapy or ESWT) could have a beneficial influence on wound healing and prevention of hypertrophic scars. ESWT considerably improves the appearance and symptoms of hypertrophic scars. However, the mechanism underlying the observed beneficial effects is not well understood. The objective of the first part of the study is to elucidate the mechanism underlying changes in cellular mechanosensitive pathways that are induced by ESWT. This review will introduce the histopathological effects on ESWT during wound healing and scar development.
The main objective of this study is to determine how much mechanical loading on dermal scars will lead to normal scar healing. The optimal duration, the frequency and the intensity of the applied forces in ESWT to generate a beneficiary effect during different phases of wound healing remains unclear.
In this study, biopsies from abdomionplasty postsurgical scars will be examined. Thereby it is possible to evaluate the outcomes on a cellular level through assessing the histology of human biopsies under controlled condition. In the second part, the underlying mechanism of ESWT on postsurgical scars will be explored, in different stages of wound healing. Furthermore, the investigators will investigate if changes in physical characteristics (redness, thickness and pliability) in postsurgical scars are associated with changes in reactivity of mechanosensitive pathways. This study will close the gap between the fundamental knowledge on cellular mechanotransduction and the clinical application of mechanotherapy during physical scar management (ESWT).
Eligible patients aged between 18 and 80 years
Dutch or English speaking
Patients who had undergone an abdominoplasty resulting in a dermal scar
Informed consent (approved by the ethics committee) will be provided before the surgical intervention
All type of skin diseases or dermatological problems
Previous surgery or ESWT intervention at the current scar site
Age under 18 years or above 80 years
Inability to provide informed consent
Parallel
Shockwave therapy
DeviceFocused ESWT will be applied to the scarred area in the 3 intervention groups. Each group will receive 10 ESWT treatments with a frequency of 1x/week. Energy levels (EFD mJ/mm2) or bar in radial can range between 0.01-0.33 mJ/mm2 (33). Based upon experimental papers, the described energy flux density, frequency and number of shots should activate or modulate the signaling pathways of interest and are used in the treatment of scars.
Change in α-SMA and myofibroblasts
Scar tissue biopsy specimens will be collected by an experienced plastic surgeon from patients who had undergone an abdominoplasty that registered for the study. The biopsy will be embedded in paraffin for histological examination. After application of local anaesthesia, a 3-4mm diameter punch biopsy will be taken to ensure the presence of the subcutis in the biopsy and to ensure sufficient tissue. After the biopsy has been taken, the small lesion will be closed by a single suture. The investigators are interested in change in α-SMA and myofibroblasts by immunohistochemistry.
Change in Macrophages
Scar tissue biopsy specimens will be collected by an experienced plastic surgeon from patients who had undergone an abdominoplasty that registered for the study. The biopsy will be embedded in paraffin for histological examination. After application of local anaesthesia, a 3-4mm diameter punch biopsy will be taken to ensure the presence of the subcutis in the biopsy and to ensure sufficient tissue. After the biopsy has been taken, the small lesion will be closed by a single suture. The investigators are interested in change in macrophages by immunohistochemistry.
Change in TGF-β
Scar tissue biopsy specimens will be collected by an experienced plastic surgeon from patients who had undergone an abdominoplasty that registered for the study. The biopsy will be embedded in paraffin for histological examination. After application of local anaesthesia, a 3-4mm diameter punch biopsy will be taken to ensure the presence of the subcutis in the biopsy and to ensure sufficient tissue. After the biopsy has been taken, the small lesion will be closed by a single suture. The investigators are interested in change in TLR3 by immunohistochemistry.
Change in collagen type I en type III
Scar tissue biopsy specimens will be collected by an experienced plastic surgeon from patients who had undergone an abdominoplasty that registered for the study. The biopsy will be embedded in paraffin for histological examination. After application of local anaesthesia, a 3-4mm diameter punch biopsy will be taken to ensure the presence of the subcutis in the biopsy and to ensure sufficient tissue. After the biopsy has been taken, the small lesion will be closed by a single suture. The investigators are interested in change in collagen type I en type III by immunohistochemistry.
Measurement of color changes in scar tissue
Colour will be measured using a Mexameter MX18 (from Courage and Khazaka) using the erythema/melanin indices. The Mexameter uses 16 light-emitting diodes that emit light at three wavelengths (green: 568 nm; red 660 nm; infrared 880 nm). Then, the reflected light is measured by a receiver unit. Erythema is measured by the green and red wavelengths, whereas melanin is determined by the red and infrared wavelengths.
Measurement of vertical elasticity changes in scar tissue
Vertical elasticity will be measured using a Cutometer Dual MPA 580®(from Courage and Khazaka). The cutometer uses a negative pressure where after the skin is drawn into the aperture of the probe.
Patient-reported outcomes on scar characteristics
The patient observer scar assessment scale is a two numerical scar assessment scale whereby the patient and observer evaluate the scar. The observer scar assessment scale-observer scale (POSAS-O 3.0) is filled in by the investigator. POSAS-P 3.0 (patient) is filled in by the patient and is a reliable instrument. A total of 16 or 17 items in the generic and linear questionnaire, aimed at measuring visual (e.g., color), tactile (e.g., pliability), and sensory (e.g., itching) characteristics of the scar. Additionally, there is 1 item regarding overall satisfaction with the scar (this item is excluded from the scoring). Each item is rated on a scale from 0 to 10, where 0 represents the best possible outcome (no scar or no issues) and 10 represents the worst possible outcome (severe issues with the scar).
Quality of life assessment in scar-affected Individuals
The Dermatology Life Quality Index (DLQI) is a questionnaire to define patient satisfaction. It quantifies the health-related quality of life of the patient by measuring the disability caused by any skin disease. The DLQI consists of 10 questions, each addressing a different aspect of how the skin condition affects the patient's life. Each question is scored on a scale from 0 to 3, where: 0 = "Not at all" (no impact); 1 = "A little" (small impact); 2 = "A lot" (moderate to significant impact); 3 = "Very much" (severe impact). The maximum possible score is 30 (if all answers are "3"). The minimum possible score is 0 (if all answers are "0"). Interpreting the DLQI Score: 0-1: No effect on quality of life 2-5: Small effect on quality of life 6-10: Moderate effect on quality of life 11-20: Very large effect on quality of life 21-30: Extremely large effect on quality of life
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Universiteit Antwerpen
Lead sponsor
Heilig Hart Ziekenhuis Lier
Collaborator
University Hospital, Antwerp
Collaborator
Ziekenhuis Rivierenland
Collaborator
AZ Middelheim, Antwerpen
Collaborator
