It's a Biomaterial World for Plastic Surgeons
by Maryann Brinley
lastic surgeons are practicing in a brave new world of everyday work. In the area of biomaterials for implanting, rebuilding, repairing and covering soft tissue wounds, burns or gaping holes in the human body naturally and safely, “there has just been an explosion in the number of products coming into the market,” according to Martha Matthews, MD, chief of the plastic surgery division at UMDNJ Robert Wood Johnson Medical School (RWJMS) in Camden.
Biologically-compatible materials and laboratory-engineered products have revolutionized treating patients, agrees Christopher J. Salgado, MD, RWJMS, assistant professor and a reconstructive micro-surgeon. He practices with Matthews at Cooper University Hospital and is conducting a clinical trial on Permacol™, made from porcine (pig) dermis, for abdominal wall repairs.
Collagen, made from bovine (cow) sources, has been around for more than 20 years, according to Matthews, who is a leading cleft-lip and palate expert as well as a cosmetic and reconstructive surgeon. “But the body gradually absorbs collagen so it disappears in a few months.” What’s nice about the newer fillers is that they last much longer and some are allergy free, so they require no advance skin testing for patient safety.” Injectable materials that plump up and fill in wrinkles are really hot,” she says. “Just check out all the ads in magazines like Vogue or Harper’s Bazaar.” Radiesse®, which has little particles of calcium in it and just received FDA approval, can last up to a year.”
From Juvederm®, Permacol™, Restylane®, Radius®, Hylaform®, AlloDerm®, TyRx®, Apligraf®, Epicel®, Laserskin®, Dermagraft®, Celaderm®, OrCel® to LSE, these substances come in all shapes, sizes, sheets, pieces, pastes or gels, and make it possible to replace missing abdominal walls, repair hernias, heal diabetic feet, reform battered body cavities, and rebuild or close traumatic holes, painful ulcers, pressure sores, wounds, fractures or the results of
cancerous tumor removal anywhere, inside and out. Some materials are capable of stimulating the body to heal as well as preventing infection. Others are grown from a patient’s own skin.
Commercially cultured skin substitutes can come from various cell sources — cows, humans, or pigs — and can be biochemically engineered. “You can take a little piece of skin from someone who has been badly burned — let’s say 80 percent of his or her body — send it off to a lab and have more skin grown for grafting,” says Salgado. “These products are expensive, however. A piece of AlloDerm®, from human cadaveric dermis, about the size of a half sheet of 8 1/2 by 11 inch paper, for example, can cost up to $5,000,” he explains. If someone had a hernia or trauma and the belly couldn’t be closed with the existing skin, it would be used routinely for that type of reconstruction. To fix these problems, surgeons have been known to implant Gore-Tex® — the same fabric found in lightweight water-proof outerwear — but if infections and fistulas in the anterior abdominal wall occur, the Gore-Tex® needs to be removed. Using these new biomaterials such as AlloDerm® or
Permacol™ prevents having to remove the implant and allows wounds to heal secondarily. Permacol™, developed by TissueScience Laboratories (TSL) in England, has been commercially available since 1998 but its use is now growing. Three-dimensional and architecturally close to human tissue, this biomaterial is sterilized with gamma radiation to prevent immune reactions and can be cut or shaped easily by a surgeon. Manufacturing does not remove the elastin from the original porcine dermis so the end product is flexible. Stronger than human skin grafts, Permacol™ will remain in place permanently, allowing cellular and vascular growth into and through the implant or covering. Unlike the fillers Matthews mentioned, which get reabsorbed by the body, the stuff stays right where it’s put. Researchers have also been using it as an injectable paste for full-thickness wounds or repairs inside body cavities. Because there were no good objective studies evaluating Permacol™ for abdominal repair, Salgado was awarded a grant by TSL. “We’ve used it on a lot of patients so we’re conducting a trial and will publish our results.”
Nowadays, new biomaterials — known in the scientific literature as decellularized dermal matrixes for grafting — make it possible to repair even the most difficult palatal fistulas, or holes, which can develop even long after surgery. “In a certain proportion, about 10 percent, of cases, the cleft palate repair won’t heal properly,” Matthews explains. Because of the constant motion, the mix of soft structures rubbing against harder, as well as the natural environmental characteristics of the nose and mouth, surgically-stubborn complications can occur. “Three weeks ago, I operated on a 50-year-old to repair a hole between his mouth and nose.” With the use of AlloDerm®, material harvested from human cadaveric dermis, to finally close it, “He healed beautifully.”
Meanwhile, Salgado’s Army years offered him extensive patient experiences. A graduate of Georgetown University School of Medicine, this surgeon spent four years in the U.S. Army during wartime — he was chief of the craniofacial board at the William Beaumont Army Medical Center in Texas until August 2004 — so he has seen how combat can wreak havoc on a human being. In fact, one of the driving forces in the advancement of plastic surgery as a medical specialty has been war. Some historians point to World War I — “the war to end all wars” with its modern weaponry that left
soldiers with gaping traumatic injuries and missing body parts — as the point at which plastic surgery took off as a discrete, creative
In spite of media attention often given to the cosmetic side of this practice, the plastic in plastic surgery is based on the Greek “plastikos,” which means to mold or give form and not on the words artificial or unnatural. “There’s a lot of energy and innovation in our field,” Matthews says, “and so many exciting new technologies and materials. It’s all amazing stuff.”