Helps Reattach Parts : Leech Gains Hold as Aid to Surgeons
The leech, the lowly leech, is getting some respect.
This bloodsucking parasite, one of the most reviled creatures in the animal kingdom--not to mention ugly--is becoming a minor hero in the world of medicine. Surgeons who have used leeches swear by them. Patients sing their praises. A few hospitals are even keeping leeches in their medicinal inventories.
Forget, for now, that image of Humphrey Bogart yanking the slimy things from his body in “The African Queen.” Substitute, instead, one of the leeches saving severed fingers, toes and ears.
The leech, once used by the millions as a cure-all in the dark days before modern medicine, has found itself a niche in the delicate world of microsurgery. When all else fails in reattaching a severed body part, the leech takes up where surgery left off.
Problem With Veins
Though this may sound bizarre, it is easily explained: When microsurgeons go about the task of reattaching a finger, for example, their goal is to reestablish the flow of blood from, and back to, the heart. The outward flow is through arteries, which are larger and easier to work with. The trickier part of the operation is rejoining the much smaller veins, which return blood to the heart.
If that part of the operation fails, blood becomes congested in the area of the wound, lowering the odds of a successful operation. Enter the two-inch-long leech. Surgeons who have tried them say that leeches placed on the reattached body part draw out the congested blood, while an anti-coagulant in the saliva of the leech prevents clotting.
Not only that, but the process doesn’t hurt, because the saliva acts as a local anesthetic, masking the three-pronged bite that, incidentally, resembles a Mercedes-Benz emblem. After leeches are used for several days, the severed veins naturally reattach themselves, greatly increasing the chances that the body will not reject the part.
‘Do Everything’
“The leeches are like a godsend,” said Dr. Fred Valauri, a microsurgeon at the Davies Medical Center in San Francisco. “They do everything a microsurgeon would want. If you wanted to design something, this is it. It’s already been made.
“This is a fantastic ace in the hole,” he said.
Certainly, Nancy Pollard of Fort Bragg is a leech fan. Last February, her 5-year-old son, Nicholas, lost two fingers on his left hand in an accident while he was playing in the family garage. Mother and son were rushed by plane to San Francisco, with Nancy Pollard carrying the severed fingers, which Valauri reconnected in a 7 1/2-hour operation. But the veins on Nicholas’ hands could not be rejoined because they were so small. When the fingers started turning black, Valauri brought out two leeches.
“That leech would go on there and bring the pink color back to his hand,” Pollard said. “It would just change in front of us.”
And although she said she got the chills the first couple of times the leeches were applied, young Nicholas was not so squeamish. He gave each of them nicknames, dubbing one “Larry the Leech.”
“I feel that besides the doctor’s wonderful knowledge, they (the leeches) played a great part in saving the fingers,” Nancy Pollard said.
Franklin Dye of Buffalo, N.Y., owes an ear to leeches. Two weeks ago he tripped on a rug, crashed through the glass door of a record cabinet and severed his right ear. He was taken to Buffalo’s Mercy Hospital, and his ear was reattached by Dr. Kulwant Bhangoo, who, though he had never used leeches before, decided that applying them was the only way to save it. Dye, a retired millwright in a steel plant, did not even flinch at the idea.
“I didn’t have anything against them to begin with,” he said.
Bhangoo said the ear is healing nicely, thanks to the time bought for the veins to reattach themselves. But he did see a paradox in the use of both microsurgery and leeches.
“We started off the treatment with the most modern, sophisticated, state-of-the-art equipment and then went to the past to augment it,” he said.
Although the thought of leeches in a doctor’s office may be disconcerting, leeches and doctors have actually been a tandem team for centuries. Roy Sawyer, one of the world’s leading experts on the subject, said leeches have been used in attempts to cure ailments since before the birth of Christ.
Sawyer, who now supplies leeches to doctors all over the world from his company in Wales, said in a telephone interview that the earliest clearly documented record of leeches being used as a cure was a medical encyclopedia from India written between 500 BC and AD 200. The Sanskrit document contained a full chapter on leeches.
The leech’s heyday, though, came in the early 1800s, particularly in France. A surgeon in Napoleon’s campaigns, Francois Broussais, took the lead in using leeches as a remedy--to the detriment of millions of people.
Broussais’ theory was that the body first had to be weakened before it could be cured. To this end, he deprived patients of proper food and heavily leeched them, reasoning that the creatures would withdraw “bad” blood and that “good” blood would replace it. One historical account said Broussais would apply as many as 50 leeches at once. It took years for this practice to fall from favor.
Sawyer said that between 1800 and 1900, more than 1 billion leeches were imported to France, and that at the peak of leeching’s popularity, from 50 million to 100 million were brought in by mule train from Eastern Europe each year.
“They were the aspirin of the day,” he said.
Although it was the French who often leeched people to death in the early 19th Century, they were also the ones who first began experimenting with the parasites in conjunction with microsurgery in the late 1970s. But Charles Lent, who has been doing research on leeches for the last 15 years at the University of Utah in Logan, said they were always being used in the interim, though sparingly, and that British hospitals never stopped stocking them.
“There’s nothing like a leech for a badly swollen black eye,” he said.
But did he really find them appealing, after all those years of research?
“I like them, and even I find them to be pretty repugnant,” he said.
Not all microsurgeons are using leeches these days for their more difficult cases. And those who do employ them in only a small percentage of their operations. A random sampling of the plastic surgery departments in the vast Houston Medical Center turned up not a single leech user, while eliciting hoots of disbelief from incredulous hospital public relations employees.
Dr. Richard Vanick, a microsurgeon at Houston’s Memorial Southwest Hospital, said he would worry about bacterial infections from leeches and the fairly diligent nursing care that would be required after surgery.
“You may have to ask the nurses to pull off the leech and put a new one on,” he said. “With my friends who have used leeches, some of the nurses have refused to do this.”
But the market for leeches is large enough now that it is supporting at least one business in the United States: Leeches USA on Long Island, which imports leeches for doctors and hospitals around the country.
“We’ve sold thousands of leeches,” said Marie Bonazinga, the company president.
Leeches USA does not raise the creatures, but imports them from Sawyer’s Biopharm company in Wales. Last year, about half of Biopharm’s 20,000 leech exports went to the United States, and Sawyer said roughly half that number went to Leeches USA.
He estimates that there are 650 varieties of leeches in the world and said the creatures he exports are known as “medicinal leeches,” whose saliva is particularly suited to assisting in surgery.
Bonazinga said that, as a matter of company policy, she did not divulge the number of clients who order leeches.
But, when the company is called on for a batch of leeches, they are shipped in moist containers via overnight express mail. Leeches USA keeps anywhere from 500 to 1,000 of the worms on hand at all times, storing them in temperature-controlled tanks and selling them for $6 apiece.
Although Leeches USA is usually the first place doctors call when they need a new supply of Hirudo medicinalis , sometimes it takes a little improvisation to get them. Valauri, the San Francisco surgeon, tells of touring the pediatric ward of New York’s Bellevue Hospital recently and stopping to examine a child whose severed finger had been reattached. The finger, however, was showing signs of rejection and Valauri was asked what he would do. Apply a leech, he said. But it was the weekend, and though Leeches USA was only a short drive away, the office was closed.
Valauri called San Francisco and ordered some of his own leeches flown in by air freight. As he expected, the leech did its job and the blackened finger turned pink.
So, are leeches here to stay? Not if Sawyer is successful. His major goal now is not just to raise and sell leeches, but also to isolate the best qualities of the worm’s saliva and then reproduce those qualities in the laboratory for pharmaceutical uses.
Clot Inhibitor
Among them are hirudin, found in European leeches, which inhibits blood clotting and allows bleeding to continue from the bite long after the parasite has fallen off. There is also an enzyme known as orgelase, which allows the hirudin to spread more quickly. Finally, there is hementin, a substance Sawyer isolated in the 18-inch-long Amazon leech, which dissolves clots after they have formed.
Copying these chemicals in the laboratory sounds good in theory, but Sawyer concedes that there is still much work to be done. He believes that, if he ultimately succeeds in his quest, the drugs produced could be applied to other problems besides reattaching fingers, toes and ears. Sawyer said the drugs could be used to speed up the use of local anesthetics, treat glaucoma, prevent thrombosis and even help in the early detection of cirrhosis of the liver.
Sawyer is realistic enough to know that the vagaries of nature can be maddeningly complex, though, and that unraveling the mysteries of the leech may take time.
“I think we are really in the business of making the leech obsolete,” he said.
