Molecular, Histologic, and Clinical Analysis of Negative Pressure Wound Therapy (NPWT) for Split-thickness Skin Graft (STSG) Donor Sites

Study Overview
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Brief Summary
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The purpose of this single-center, randomized, prospective cohort study is to evaluate the clinical outcome and negative-pressure wound therapy (NPWT) mediated modulation of the biologic milieu of a modified NPWT dressing on split-thickness skin graft (STSG) donor sites.

Detailed Description
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The investigators have designed a prospective randomized trial in which subjects will be assigned to a modified negative-pressure wound therapy (NPWT) dressing or standard moist dressing. The investigators will measure the percentage of re-epithelization at set postoperative time intervals using digital photography, pain using the visual analog scale (VAS), and healing quality using the Vancouver Scar Scale (VSS). The investigators hypothesize that the NPWT will lead to less pain and increased re-epithelization in a shorter postoperative time course. This specific aim seeks to prove/disprove that patients who receive a modified NPWT dressing perceive the advantage with improved healing, pain, shorter length of stay, and other wound symptoms related to delayed donor site wound healing. The donor site for STSGs provides a consistent model of superficial wounds that offers the opportunity to study both mechanisms of wound healing and potential mechanisms of action of NPWT. In patients undergoing both standard dressings and NPWT, the investigators will sample the wound exudate and perform microbiopsies of the healing wound at fixed intervals and perform histologic and molecular analysis in order to quantify the degree of re-epithelization and the trophic and inflammatory profile of the healing wound.

Official Title
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Molecular, Histologic, and Clinical Analysis of Negative Pressure Wound Therapy (NPWT) for Split-thickness Skin Graft (STSG) Donor Sites

Conditions
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Split-thickness Skin Graft Donor Sites, Burns

Intervention / Treatment
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* Device: Modified NPWT dressing
* Device: Tegaderm


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-60 Both genders are eligible for study Written consent obtained from the subject or agent Donor site wounds must not exceed 5% total body surface area (TBSA) Subject must be receiving a split-thickness skin graft (STSG) Donor site is amenable to either NPWT or standard of care (occlusive dressing) Ability to comply with necessary wound care/follow up Exclusion Criteria: Age <18 years Subject has been diagnosed with Diabetes Subject is a smoker Subject takes steroids Subject takes immunosuppressive medications Subject with immunosuppressive disorders Donor site wounds that exceed 5% total body surface area (TBSA) Subject has sensitivity to silver or acrylic adhesives Inability to comply with necessary wound care/follow up.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental: Modified NPWT dressing<br>In the experimental group, a microporous silver-impregnated foam with a thin silicone contact layer (Mepilex Ag) will be applied. A macroporous foam layer (V.A.C. GranuFoam) and an occlusive dressing (V.A.C. Drape) will then be applied to cover the foam, plus 3-5cm border of intact skin. The occlusive dressing will then be pinched and a 2cm hole will be cut to apply the SensaT.R.A.C. Pad that supplies pressure from the NPWT unit. NPWT will be applied at 125mmHg throughout treatment using KCI's InfoV.A.C. Therapy Unit. The donor site dressing will be replaced on postoperative day 5-7 and a new occlusive dressing (Tegaderm) will be applied. | Device: Modified NPWT dressing<br>* Use of negative pressure wound therapy on split-thickness skin graft (STSG) donor sites<br>Device: Tegaderm<br>* Standard of care for STSG donor sites.<br>|
| Active Comparator: Control: Tegaderm<br>In the control group, the donor sites will be dressed with an occlusive dressing only (Tegaderm). The donor site dressings will be replaced on postoperative day 5-7 and a new occlusive dressing (Tegaderm) will be applied. | Device: Tegaderm<br>* Standard of care for STSG donor sites.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain as measured by visual analog scale (VAS). |  | Assessed up to 14 days | 
| Wound healing rate (re-epithelialization) | Evaluated by the investigator and by a blinded expert using photographs. | Assessed up to 1 month | 
| Wound exudate: mRNA expression | Wound exudate and tissue lysate will be subjected to polymerase chain reaction (PCR) for semi-quantitative analysis of mRNA expression. | Assessed up to 14 days | 
| Wound exudate: protein content | Quantitative enzyme-linked immunosorbent assay (ELISA) will allow analysis of target protein content. | Assessed up to 14 days | 
| Tissue sample: re-epithelialization and granulation percentage | Tissue samples will be fixed and processed for hematoxylin and eosin (H&E) staining and analyzed microscopically for re-epithelialization percentage. | Assessed up to 14 days | 
| Tissue sample: epidermal thickness | Tissue samples will be fixed and processed for hematoxylin and eosin (H&E) staining and analyzed microscopically for epidermal thickness. | Assessed up to 14 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wound Healing Quality | As measured by the Vancouver scar scale (VAS) | Assessed up to 1 month postoperatively | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Split-thickness skin graft, STSG, donor site, negative-pressure wound therapy, NPWT, dressing