It’s 7:30 p.m, just a little after bedtime for most of the children at the Boston Shriners Burn Hospital. Pictures of fuzzy animals and popular cartoon characters don the walls. A few nurses calmly stroll along wearing candy-store colors. Down the hall, there’s a playroom with all the toys a kid could ever ask for.

At first glance, you’d expect the worst case here to be a tonsillectomy patient who’s been eating too much ice cream.
Bob Sheridan, chief of burn surgery, gives his watch a quick glance and starts his rounds. First on the docket: Lisa, room 803. Only five-years-old, she was badly burned over much of her right side two days ago when an electrical fire broke out in her room while she was sleeping. She’s relying on a respirator, but her attending nurse has to stop in every hour or so to change the position of the hose connected to her mask so that she can lie with her face in a different direction. If her head is still for too long, the burns on her neck will begin to form tough scar tissue that will tether her head in that position.

As bad as she looks on the outside, twenty years ago it would have been her internal organs--her lungs and heart--that would have concerned Sheridan. Most severe burn victims, especially children, die from the broiling their lungs take from the fire’s super-heated gases, the muck left over from the smoke, or the extra strain on a heart that’s beating like a blown tire to rush blood to damaged tissues and to lungs gasping for oxygen. The greatest advancements in treatment have come from simply learning that, before work begins on closing wounds, the patient needs the proper fluids and oxygen-rich air from a respirator.
“Now, our biggest concern usually isn’t survival,” Sheridan says, “It’s making sure that the patient can come out of the experience and get back to as much of a normal life as possible. And that means dealing with scarring.”

Thankfully, the fire spared Lisa’s face; but her neck, right arm and leg were badly hurt. The human skin can take a remarkable amount of damage. Still, burns aren’t normal injuries. You can’t sew them up like a cut. You can’t expect them to mend like a bone. “The body doesn’t know how to react to a burn,” Sheridan says. Evolution has equipped our bodies with tools to deal with bumps, slashes, and even extremes in weather. Burns trick these tools into working against us. When the body tries to scar over large, severely damaged areas, the skin becomes inflexible, numb, and disfiguring. Where there was once pliable skin, there’s now a tight, shiny film that tears before it stretches.

It’s now Sheridan’s job to minimize these effects to give Lisa the most normal life possible. In his toolbox are a set of newly developed techniques that combine plastic surgery with skin grafts. And it’s a toolbox he’ll soon be adding to.

Normal skin has two layers. The epidermis is a thin, outer layer of cells that protect from outside chemicals and objects. This layer is meant to take punishment and can recover from most of the damage it takes. Below the epidermis lies the thick, deep dermis, made primarily out of protein filaments called collage. Like wet cotton batting in a pillow, it gives skin both firmness and pliability. Buried in this collagen, you’ll find sweat glands, hair roots, blood vessels, nerves, and the motile fibroblast cells that spin the collagen.

Scars form when fibroblasts overreact to damage to the dermis. Instead of calmly waiting for a new network of intricately knit collagen filaments and epidermal cells to grow, the fibroblasts firehose in a super-dense mix of collagen that cements the wound closed. This collagen is so thick that no hair roots, sweat glands, and very few nerves can grow into it.

This quick fix works fine for nicks and cuts. It’s even an evolutionary advantage because it gives padding to an area that takes a lot of superficial damage, like knees that are constantly getting scraped. In a third-degree burn, where large areas are deeply destroyed, the body will try to replace the whole section with scar tissue. Instead of forming padding, it replaces a whole depth of damaged skin. All the functionality of skin--the ability to sweat, feel and regulate body temperature--is lost to this inflexible mass. To compound matters, the dense collagen shrinks as it heals, puling the surrounding skin. If this was allowed to happen in an area like Lisa’s hands, they would be frozen into a claw shape.

Typically, surgeons prevent these complications by artificially filling in the damaged skin with a substitute, says Dr. Stephen King, the medical director at the Wound Care Center in Memphis. The most popular substitute is a skin graft taken from the patient, usually from the inner thigh. The graft is the epidermis and enough of the dermis to keep the epidermis alive for a little while. Usually, though, the grafts aren’t meant to be long term replacements since blood vessels can’t grow into them fast enough to keep them alive. They’re just patches to loosely complete the structure of the skin to fool the fibroblasts into building only a thin layer of scar between the graft and the skin. To make grafts take, doctors must perform microvascular surgery to connect blood vessels in the graft to the pipe work of the damaged area. The procedure is costly, time-consuming and excruciating intricate. In many instances, the damage to the supporting blood vessels is too extensive, and the operation fails.

For some patients, there just isn’t enough skin to go around. When too much of a patient is covered in burns, other fillers have to be found. Thirty years ago, this likely would have been refrigerated cadaver skin. Today, artificial skins offer a more reliable, more sanitary solution. The most commonly used artificial skins are made of a thin sheet of silicon covering a thick layer of specially processed collagen taken from cow bone. This loosely packed collagen is soaked with nutrients that act like comfort food to the fibroblasts, drawing them out of the frenzied pace and to the slower process of replacing the cow collagen with their own. With the fibroblasts following the cow collagen template, the result is much less tightly packed, leaving something less than skin but much more tactile than a scar.

In as little as two years, artificial skin grafts may leave patients like Lisa with scars virtually indistinguishable from real skin. King is currently developing a technique in which he grafts a layer of epidermis scavenged from the patient’s body onto the artificial skin collagen. The trick is putting the epidermis on in the small window of time after enough small blood vessels have worked their way into the collagen to provide blood flow, but before the collagen has been completely rebuilt by the body’s fibroblasts. Without blood flow, the cells will die from lack of oxygen and nutrients. If the collagen has to be rebuilt, it’s officially a healed scar and the epidermis can’t grow into it. If successful, the end result (which has already been tested on a few firemen) looks, wrinkles, and stretches like skin, although it does lack the ability to sweat or to grow hair.

Those problems, however, might be solved by the work Dr. Steven T. Boyce at the University of Cincinnati. With Boyce’s technique, a sample of the patient’s epithelium is taken and then grown like a bacteria colony on top of a layer of animal collagen. The collagen is soaked in a special mix of nutrients that allow the epithelium to fully form, resulting in a piece of functional pseudo skin that can feed off of its own nutrients until it merges with the body’s blood flow. The result is a visibly perfect replica. This technique is expected to move into clinical trials in 2005.


For now, Sheridan expects that Lisa will have to make due with silicon grafts that only reduce scarring. Instead, she’ll work with a therapist who will teach her exercises that will bend and stretch the scar tissue while it is forming, so there will be enough elasticity for her to move. She’s young enough that as she gets older and her skin continues to grow, doctors will be able to cut areas of scar tissue out of her skin. They’ll then stretch and sew the loose ends back together, leaving a seam instead of a scar patch.

For the areas that will never be removed or grafted over, Lisa has several options to help lessen the appearance of scarred tissue, said Peter Lorenz, an associate professor of plastic surgery at Stanford University. Dermabrasion uses a hand-held grinding tool to sand off the top layer scar tissue, giving a smoother appearance to rough scars. Laser resurfacing does the same thing by disintegrating away the top portion of the scars. To flesh out any discolorations, micropigmentation uses needles to deliver tiny amounts of pigment into the skin, a process similar to tattooing. Lorenz is also currently working with a regiment of steroids that, when injected, begins a hormonal reaction that melts the collagen inside large and lumpy scars, not only flattening them out, but also making them more elastic.

Tonight, Lisa’s alive and sleeping with her two parents watching her from the foot of her bed. The future will hold years of surgeries and therapy. There will always be scars. But those scars won’t stop her life. They won’t keep her from playing sports or dating.

Sheridan is optimistic. “Now is when it all starts. What we plan to do for her tonight will affect how she lives the rest of her life,” he says. “But there’s no telling what new improvement we might be able to use next year to help her out.” He pauses. “As the future comes, her life will get better and better.”