January 9, 1998

Restoring lives: researchers look for best burn treatment

34-year old Greg Goulet suffered burns to 70 percent of his body in an industrial flash fire. After his wounds healed, he underwent the long process of recovery.
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1. Plaster of paris strips are applied to Greg's face to obtain a cast of the face. 2. Plastic custom face mask applies pressure to flatten and soften hypertrophic scare. 3. Greg alternates between wearing the plastic mask and more comfortable lasticized custom face mask. 4. "It's been a very long road. A lot of different stages: anger, why me, depression. What I did was keep as positive an attitude as I could. That's how you get through something like this."

It takes just a few seconds for fire to completely consume ordinary clothing and human flesh. Full thickness burns, which destroy every layer of skin can take weeks to heal. That is, if the victim survives the critical first days.

The University of Alberta Firefighter's Burn Treatment Unit has made significant improvements in helping patients through those critical first days. Ten years ago the average length of stay in hospital was 26 days and 4.1 per cent of critically-burned patients died. Today, similarly injured patients would spend just 14 days in hospital and face a 2.4 per cent mortality rate.

"It's still not zero," says Dr. Edward Tredget, director of the Plastic Surgery Research Laboratory, "but we've got better at helping people stay alive."

The Firefighters' Burn Treatment Unit treats about 200 patients a year. Tredget says the majority are children or young men in the productive phase of life. "In young children, we see a lot of scald injuries, liquids spilled from above down over the face and shoulder. We also see many adult males injured on the job-flash fires, petroleum injuries."

Such injuries can be physically devastating, but Tredget says the most difficult wound to treat is often the psychological one, particularly in a woman or young child with a facial burn. "We see a lot of depression in adults, poor social adjustment in children, difficulty relating to peers-a lot of unhappiness."

It's not enough to just ensure patients survive, Tredget says, but to ensure their quality of life patients need a good cosmetic result and sufficient mobility and range of motion, despite scarring.

Tredget compares skin structure to the structure of a house. The outer layer or epidermis is like the roof: it provides protection from the elements and even flakes off like shingles do. The underlying tissue or dermis is like the rafters, providing support and structure. That's where the comparison ends, however. Real roofs and rafters can be easily rebuilt.

The complicated, painful process of rebuilding skin can take years-but the University of Alberta has made inroads.

U of A researchers were among the first in the world to graft skin onto new burns. The skin is collected from cadavers (allograft) or healthy areas on a patient's body (autograft). It can be applied immediately or stored in the Firefighters' Skin Bank, one of the first to be accredited by the American Association of Tissue Banks. "Last year we had about 15 to 20 requests for allograft skin from other North American institutions," Tredget says.

Tredget notes there are some problems with allograft skin. It's only a temporary epidermal cover to prevent infection and fluid loss. Moreover, skin contains many immune cells so compatibility is a big problem. But a revolutionary burn treatment may change that.

Researchers are close to a treatment that will help patients heal faster with a less disfiguring scar. Scar tissue looks different than skin, Tredget says because scar tissue is missing some original elements. The answer may lie within the patient's genes.

The new treatment, called topical gene therapy, involves taking punch biopsies of a patient's healthy skin, genetically altering it, and growing it in the lab. Biochemist Paul Scott is working on restoring the missing proteins and proteoglycins in the skin cells. Molecular biologist Aziz Ghahary adds cloned growth factors to the skin cells. The delicate tissue resembling onion skin grows rapidly; within a week, a square centimetre can expand to ten square centimetres. When the tissue is placed onto a wound, it continues to grow, accelerating the healing process.

"The beauty of this treatment," says Dr. Ghahary, "is you can use the same cells from the same patient so the rate of rejection is very minimal. We can add the gene of interest that continuously produces the needed protein. It's much cheaper, and won't break down - even if it does, patients can just reproduce the cells. The result is a better, faster, less expensive healing, that's less likely to infect, with less fluid lost."

Ghahary anticipates topical gene therapy will be ready for human trials within two years.

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