主题：这个外科医疗术值得讨论讨论。 -- 九霄环珮

Kathleen A. Greer • Senior Editor • Advances in Skin & Wound

Care • Ambler, PA

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.

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 costeffective

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 laborintensive

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.

Selected References

Graninger M, Grassberger M, Galehr E, et al. Comments, opinions, and brief case reports: biosurgical

debridement facilitates healing of chronic skin ulcers. Arch Intern Med 2002;

162:1906-7.

Jukema GN, Menon AG, Bernards AT, et al. Amputation-sparing treatment by nature: “surgical”

maggots revisited. Clin Infect Dis 2002;35:1566-71.

Sherman RA. Maggot therapy for treating diabetic foot ulcers unresponsive to conventional

therapy. Diabetes Care 2003;26:446-51.

Sherman RA. Maggot vs conservative debridement therapy for the treatment of pressure

ulcers. Wound Repair Regen 2002;10:208-14.

Sherman RA, Shimoda KJ. Presurgical maggot debridement of soft tissue wounds is associated

with decreased rates of postoperative infection. Clin Infect Dis 2004;39:1067-70.

Wollina U, Liebold K, Schmidt WD, et al. Biosurgery supports granulation and debridement in

chronic wounds—clinical data and remittance spectroscopy measurement. Int J Dermatol

2002;41:635-9.