Skin from a deceased donor’s face // Fat // Milled bone chips // Resorbable tacks // Fibrin glue // Biodegradable scaffolding // And most critical, not expecting too much too soon.
From top: Erin Patrice O’Brien/Getty Images; Erik von Weber/Getty Images (2); David Sacks/Getty Images
People who have suffered disfiguring injuries never grow accustomed to the stares, the double takes, the not-so-discreet shudders. Longing to disappear into the crowd, they may submit to dozens of unimaginably painful surgeries. To reclaim a burned face, for example, substitute patches of skin must be transplanted from elsewhere on the patient’s body. Both sites—where the skin is taken and where it’s sewn back into place—must heal, and infection is always a danger. If the skin is from another person, rejection is a risk. For most reconstructive surgeries, the degree of difficulty is high, and the probability of dramatic improvement can be low. And yet, so pronounced is the psychological trauma of disfigurement that there is never a shortage of volunteers for procedures that offer the possibility, however slim, of replacing what has seemed forever lost.
Maria Siemionow, director of plastic-surgery research and head of microsurgery training at the Cleveland Clinic, has been flooded with requests since the announcement in late 2004 that she is ready to transplant a face. But her search for the right combination of donor and recipient could take months, even years. Siemionow hopes to avoid the controversy surrounding the first partial face transplant, performed in France in November on a woman who had been mauled by her dog.
Similarly, transplant surgeon Joseph Vacanti and plastic surgeon Michael Yaremchuk at the Massachusetts General Hospital (MGH) in Boston must gently discourage all those hoping for too much too soon. Vacanti and Yaremchuk are working toward the day when it will be possible to fashion a wide range of human spare parts from cells implanted on a biodegradable scaffolding that dissolves as new tissue takes hold.
And after Hans-Peter Howaldt, a craniomaxillofacial surgeon at Germany’s University of Giessen, began using stem cells harvested from a patient’s own fat to repair skull defects, his office began receiving pictures of children whose parents hoped they might be candidates for the new procedure. Yet, for the most part, all of this pioneering work is years from routine clinical applications. For now, patients searching for alternatives to today’s standard reconstructive approaches must content themselves with hints of what may someday come to pass.
By the time Howaldt saw “Maria,” a seven-year-old who had nearly died from a fall out of a second-story window, two years of chronic infections and failed surgeries had left her skull so full of holes that she was wearing a helmet to protect her brain. Had Maria been older, Howaldt could have used a titanium implant or bone graft to repair the damage, but that wouldn’t work with a skull that would continue to grow for years. What’s more, because of Maria’s youth, transplanting bone from elsewhere in her body wasn’t an option. “You cannot harvest enough bone from a child that age,” says Howaldt.
But for months, Howaldt had been ready to try an approach using stem cells, the primitive cells that maintain and repair the tissues and organs in which they reside. Though never before attempted on a patient, the procedure had shown promise in animals.
The stem cells in children and adults are more limited than undifferentiated embryonic stem cells. Not yet established as a nerve or blood or any of the body’s numerous other cell types, embryonic stem cells can become almost any kind of cell, and researchers hope someday to coax them into a multitude of miraculous cures. Still, even adult stem cells are proving to be versatile and curative. (For example, those from bone marrow can be used to regenerate blood cells following high-dose chemotherapy.) And now scientists have identified stem cells in the liver, brain, blood and skin that, with prompting, can become a host of other cell types. The problem is that the cells in all those locales are few in number and difficult to extract.