Last year, the Food and Drug Administration (FDA) gave permission to market maggots as the first "live" medical device. In a recent interview with Advances in Skin & Wound Care, researcher Ronald Sherman, MD, MSc, discussed how maggot therapy can help wound healing and shared his thoughts on the future use of this age-old therapy. Dr Sherman is Assistant Researcher, University of California, and Director, BioTherapeutics, Education and Research Foundation (BTER), both in Irvine, CA.
Q: How do maggots help kill bacteria and stimulate granulation, as well as debride wounds?
A: In January 2004, the FDA gave clearance to produce and market medical maggots for "debriding non-healing necrotic skin and soft tissue wounds, including pressure ulcers, venous stasis ulcers, neuropathic foot ulcers, and non-healing traumatic or post surgical wounds." In July 2004, our laboratory at the University of California, Irvine, registered with the FDA as a production site for medical maggots. The FDA has not considered, nor approved, any claims of disinfection or growth-promoting properties. Nevertheless, there are both clinical and scientific studies that address the antibacterial and growth-promoting properties of maggots.
Debridement results when the maggots release their potent proteolytic digestive enzymes into the wound bed. The wound bed is like a dinner table to maggots. These enzymes gain access to the deeper necrotic tissue through the mechanical debridement action of the maggots' "mouth hooks"-2 probing appendages near their toothless mouth. Mixed with these enzymes-or perhaps directly as a result of some of these enzymes-many microorganisms within the wound bed are killed.
Other infectious organisms are ingested by the maggots, along with the partially digested necrotic tissue, and are later killed within the maggot's gut. These secretions have been shown to stimulate cells in culture and are associated with the rapid growth of epithelial and granulation tissue in vivo. Wound healing effects may also be due to the apparent increase in local perfusion and oxygenation that has been recorded during maggot therapy.
MAGGOT THERAPY AT WORK
Photos show the foot of a 59-year-old man with diabetes who refused amputation despite osteomyelitis. Maggot therapy debrided his wounds, including the nonviable big toe; the remains of that toe were removed surgically. One and a half years later, he left the facility with his foot fully healed.
Q: Are maggots used only in specialized wound centers?
A: Medical maggots are used today in more than 300 sites around the country, including specialized wound centers and tertiary care hospitals, specialized and general medical outpatient clinics, extended care facilities, private practitioners' offices, and even by visiting nurses who apply the maggot dressings in patients' homes.
Q: In appropriate cases, is maggot therapy more cost-effective for patients than traditional surgical procedures?
A: No therapy should ever be selected purely on the basis of cost. We are discussing maggots today because of their demonstrated efficacy, not simply their low cost. Nevertheless, cost-effectiveness is a part of any meaningful discussion of medical care. And the low cost of maggot therapy has often been touted as one of its major attributes. The few studies that have addressed the issue of cost indicate that maggot therapy is, indeed, more cost-effective than comparable standard surgical or nonsurgical treatments.
We are not in a position to quantify the cost savings, but we can surmise that it must be substantial, based on 2 observations. In Europe, where national, single-payer health care is the norm, maggot therapy has become an increasingly common practice. Approximately 30,000 maggot treatments are administered annually in Europe. But there has been less demand in the United States, where insurance coverage of maggot therapy varies. In fact, the US demand for medical-grade maggots has been too small to support a single commercial supplier. Thus, the nonprofit BTER Foundation is subsidizing the production and patient care costs through donations.
The cost-effectiveness of maggot therapy is apparent to many in the United States, however. Some hospitals tell me they prefer to pay for maggots from their own operating budgets to cure wounds and discharge patients faster than to use more conventional, billable treatments. The major expense associated with maggot therapy is the labor-intensive cost of preparing the perishable maggots. And, it requires clinical time to secure dressings upon the wound.
Q: Do you believe maggots will be more widely used for wound treatment in the near future?
A: The use of maggot therapy will soon increase, just as it has in the rest of the world. In the United States, the demand for medical maggots has increased by about 20% per year over the past 10 years. Since the FDA ruling last year, the demand has already doubled.
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