Leeches and maggots

New York Times

August 25, 2005
Age-Old Cures, Like the Maggot, Get U.S. Hearing

By GARDINER HARRIS

WASHINGTON, Aug. 24 - Flesh-eating maggots and bloodsucking leeches,
long thought of as the tools of bygone medicine, have experienced a
quiet renaissance among high-tech surgeons, and for two days beginning
Thursday a federal board of medical advisers will discuss how to
regulate them.

Leeches, it turns out, are particularly good at draining excess blood
from surgically reattached or transplanted appendages. As microsurgeons
tackle feats like reattaching hands, scalps and even faces, leeches
have become indispensable.

And maggots clean festering wounds that fail to heal, as among
diabetics, better than almost anything else, although their use in the
United States has been slight, in part because of squeamishness.

But neither leeches nor maggots have ever been subject to thorough
regulation by the Food and Drug Administration. So the medical advisers
are being asked to create general guidelines about how they should be
safely grown, transported and sold.

Since 1976, the F.D.A. has required that makers of medical devices
prove that their products are safe and effective. Those already on the
market as of that year had to prove their worth; those invented later
had to get approval before marketing.

There are unexplored corners of the nation's medical market, however -
no one knows how many, but they are certainly a vanishing few - in
which doctors and manufacturers have been doing business since well
before 1976 without much notice from the agency. The sale of maggots
and leeches is one of those corners.

In addressing it, officials first had to decide which part of the
agency had oversight: its biological or device division.

"The primary mode of action for maggots is chewing," said Mark
Melkerson, acting director of the Division of General, Restorative and
Neurological Devices. "For leeches, it's the eating of blood. Those are
mechanical processes." Thus, the agency decided that maggots and
leeches were devices, Mr. Melkerson said.

For centuries, doctors used leeches in the mistaken view that they
would help balance a patient's body fluids, or "humors." Doctors are
said to have drained quarts of blood from an ailing George Washington
before he died.

With the development of modern medicine, leeches fell out of favor. But
in the 1970's they again became popular, this time with microsurgeons.

When reattaching or transplanting an appendage, these surgeons are
often able to stitch together arteries, which deliver blood to the
appendage and are thick-walled and relatively easy to suture. Far
harder is finding and attaching veins, which collect blood for exit and
are smaller and more fragile.

After surgery, with few veins connected, blood tends to engorge the
appendage, then to clot, turn blue and - in the worst cases - kill it,
said Dr. L. Scott Levin, a Duke University hand surgeon. To buy time
for the body to create its own veinous attachments, surgeons use
leeches.

Leeches naturally inject patients with a potent chemical cocktail that
includes an anticoagulant, an anesthetic, an antibiotic and a substance
that dilates blood vessels. This cocktail encourages fast bleeding to
empty the appendage of extra blood, reducing pressure and allowing
veins to form on their own.

In 20 minutes, a leech is usually engorged and removed, though bleeding
from the wound may continue for up to 24 hours. If an appendage is
large, several leeches are sometimes used at once, Dr. Levin said,
adding, "I'll use one to three leeches every couple of hours."

Leeches are also extraordinarily sensitive to proper blood flow and so
can offer immediate feedback on how well surgery went, said Dr. Bruce
Minkin, a hand surgeon in Asheville, N.C.

"It won't attach if there's not good arterial blood coming in, and
sometimes that tells me that I need to go back in," Dr. Minkin said.

Josh Combs, 17, of Asheville needed leeches to save a thumb that had
been reattached after being blown off by a homemade firecracker. His
mother, Sherry Combs, said she was startled when Dr. Minkin told her
what he was going to do.

"I said, 'Can you tell me what you just said again, please?' " Ms.
Combs recalled in an interview.

Ms. Combs has two phobias: mushrooms and leeches. So she stood away,
over by the door, while a leech was applied to her son's thumb.

"I was afraid he would wake up suddenly and see a leech stuck to his
hand," Ms. Combs said. Josh later did just that, with another leech,
which he named Fred.

As for maggots, they are unparalleled in their ability to clean
festering, gangrenous wounds. For diabetics and others whose wounds
fail to heal, maggots, pressed into dying flesh by wire-mesh bandages,
can save a limb and speed healing.

Primitive tribes in Australia, the hill people of northern Burma and
the Mayans of Central America are known to have used maggots to clean
wounds. Napoleon's surgeon in chief noted their effects.

And during World War I, a doctor described seeing two soldiers who had
been left wounded on the battlefield for days. When their clothes were
taken off, thousands of maggots were found in their wounds. Once the
maggots were removed, the doctor was astonished to find clean, pink,
living flesh. That doctor, William Baer of the Johns Hopkins School of
Medicine, became maggots' modern medical champion.

Another oddity whose regulation will be discussed by the advisory board
starting Thursday is bone wax. That product - made of beeswax, olive
oil and phenol - has long been used by surgeons to stop bleeding in
bones cut during surgery, since neither cauterization nor pressure
works well on them. And it is sometimes used to discourage unwanted
bone regrowth, said Dr. Glenn Pfeffer, director of foot and ankle
surgery at Cedars-Sinai Medical Center in Los Angeles.

"I just had a spur on my foot taken out," Dr. Pfeffer said. "And the
surgeon applied bone wax to the cut ends to make sure it doesn't
re-form."

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