Therapy with maggots can heal a wound

1/15/2001

In one of those “yuck” scenes from the popular film, Gladiator, actor Russell Crowe miraculously recovers from a badly infected arm wound - thanks to medicine's smallest surgeons.

Crowe showcased a natural medical treatment that really has saved wounded soldiers since ancient Rome - and probably much earlier in history. Maggots, housefly larvae, had gotten into the gladiator's wound. They kept the wound clean and infection-free so it could heal.

Battlefield surgeons long ago realized that larval action in removing dead tissue and destroying bacteria often meant that a soldier would recover from a severely infected wound. In contrast, those with similar wounds given regular treatment often died from massive infections or needed amputations.

Maggot therapy was widely used in the early 1900s, until antibiotics replaced it in the 1940s.

Now modern physicians are showing new interest in maggot therapy for treating some of the most stubborn wounds, including leg ulcers, bed sores, diabetic foot wounds, infected surgical incisions, burns, abscesses, and infections caused by accidental injuries.

Patients with these wounds often face a long, expensive medical ordeal. It may involve months of treatment with antibiotics and repeated surgery to remove dead tissue from the wound.

Maggot therapy also is getting a new name and a high-tech aspect.

Today, doctors call it larval therapy, biotherapy, biosurgery, or maggot debridement therapy (MDT), and have incorporated the tiny surgeons into high-tech wound dressings that ease some of the “yuck” factor.

Surprisingly, it may be a “yuck” from doctors and nurses that hinders wider use of MDT, according to an article in November's Journal of the American Medical Association (JAMA).

“It is staff, not patients, who are the squeamish ones,” said Dr. Michael Walker, a British vascular surgeon who reported results of a new study using maggot therapy on leg ulcers. “Nursing staff are more reluctant to consider this therapy than patients themselves. We have never had a patient decline the maggots.”

The study was done as part of an effort to get Britain's National Health Service to routinely reimburse for larval therapy. Dr. Walker's small pilot study involved 12 patients with severe leg ulcers. Half got larval therapy and half conventional treatment.

After just three days, all six patients on larval therapy had wounds that were on the road to healing. The wounds were clean and free of dead and dying tissue. After one month, only two of the other patients had clean wounds.

Studies in the United States and other countries show similar results.

Larvae work by performing their own version of “debridement,” a surgical procedure to remove dead tissue from a wound. Tissue dies in severe wounds, breeding bacteria and preventing healing. People with leg ulcers and other severe wounds often must undergo repeated surgical debridement to clean the wound so it can heal.

These mini-surgeons remove only dead, or “necrotic,” tissue in a wound, according to Dr. Ronald A. Sherman, of the University of California at Irvine. Maggots are toothless and don't nibble. They secrete enzymes that liquefy dead tissue and have an antibiotic effect in the wound.

Dr. Sherman is the leading authority on MDT therapy in the United States and supplies hundreds of physicians.

MDT is covered by Medicare, Medicaid, and private insurance companies, Dr. Sherman pointed out.

JAMA said that MDT is rapidly gaining popularity in the United Kingdom, Europe, and other countries partly because of the growing problem of antibiotic-resistant bacteria. It estimated that about 350 medical centers in those areas use MDT.

Michael Woods is the Blade's science editor. Email him at mwoods@theblade.com.