Two kinds of end point are commonly used in clinical trials: those reported by the patient (for example: “On a scale of 0-10, how itchy is your skin graft this week?”) and those that are measured directly (for example, measurement of skin hardness using a special device). The RELIEF trial uses both of these approaches. For healing of the skin graft the RELIEF trial uses photographs of the wound over time as well as having the patient’s burn surgeon score the wound. RELIEF also uses standard clinical measures of healing of burn wounds including asking questions related to pain, itchiness, and a scoring system called the Vancouver Scar Scale (in which the surgeon scores several different parameters of the skin).

The Vancouver Scar Scale

ParameterFeatureScore
Vascularity
  • Normal
  • Pink
  • Red
  • Purple
  • 0
  • 1
  • 2
  • 3
Pigmentation
  • Normal
  • Hypo-pigmentation
  • Mixed-pigmentation
  • Hyper-pigmentation
  • 0
  • 1
  • 2
  • 3
Pliability (Elasticity)
  • Normal
  • Supple (flexible with minimal resistance)
  • Yielding (giving way to pressure)
  • Firm (inflexible, not easily moved)
  • Banding (rope-like tissue that blanches with extension of the scar)
  • Contracture (permanent shortening, producing deformity or distortion)
  • 0
  • 1
  • 2
  • 3
  • 4
  • 5
Height
  • Flat
  • <2mm
  • 2-5mm
  • >5mm
  • 0
  • 1
  • 2
  • 3
Pain
  • None
  • Occasional
  • Requires Medication
  • 0
  • 1
  • 2
Itchiness
  • None
  • Occasional
  • Requires Medication
  • 0
  • 1
  • 2

While very useful this kind of assessment can be biased by things like the amount of pain medication a patient is receiving at the time or just by a patient forgetting how much pain they were in the last time they visited their doctor.

For this reason, the RELIEF trial uses a small set of devices that directly and objectively measure particular parameters associated with skin and skin function. Each of these tests requires less than a minute or two. As a result, the Investigators will be able to get quick accurate information about the patient’s skin function without any pain or discomfort to the patient.

One of the most important functions of skin is as a barrier, stopping water inside the body from evaporating away and by keeping bacteria and other organisms outside the body. In the first couple of weeks after a meshed skin graft is applied the ability of the graft to act as a barrier is limited and water evaporation through the wound can be a significant problem. This is referred to as transepidermal water loss (TEWL). Restoration of the water barrier function is an important measure of healing of the skin.

Transepidermal water loss can be measured using a device called a Vapometer. By seeing how quickly water loss return to normal the RELIEF Investigators will be able to determine how quickly the wound is healing and returning to normal skin function. In the RELIEF Trial the Vapometer will be used to measure healing in the first few weeks after treatment.

Another important measurement of skin function is hardness. Skin that is scarred can be very hard and will not move much when touched whereas healthy skin is soft and pliable. Three months after treatment (by which time the skin graft will fully healed), the RELIEF trial will use a device called the SkinFibroMeter to measure how hard the patient’s skin is. This device will be placed on the healed skin to see how much the skin moves in response to a very small force. The SkinFibroMeter measures this movement to give an accurate way of measuring skin hardness.

For example, skin that is scarred is very hard and will not move much when touched whereas healthy skin will be soft and move a few 1/8 ths of an inch. Starting three months after treatment (by which time the skin graft will fully healed), the RELIEF trial will use a device called the SkinFibroMeter to measure how hard the patient’s skin is. This device will be placed against the healed skin to see how much the skin moves in response to a very small force. The SkinFibroMeter measures this movement to give an accurate way of measuring skin hardness. At the same time points (starting after three months) other measurements will be made using the same approach to look at skin elasticity and—because scars are often discolored—at the color of the skin or scar.

With this combination of patient and surgeon-reported end points and directly measured end points, the RELIEF trial seeks to get an accurate picture of how burn wounds heal and how that might be improved by treatment with ADRCs

Images of wound assessment equipment used with permission of Delfin Technologies Ltd.

Links to external or third party websites on this site are provided solely for visitors’ convenience. When you access an external website, please note that Cytori is not responsible for the information, content or product(s) found on third party websites.