Bloodsucking Leeches


(This 752nd Buffalo Sunday News column was first published on August 28, 2005.)


An event from long ago remains vivid in my mind.


Each summer when I was still in elementary school the Pitts family joined mine to spend two weeks at the Fish Creek Ponds public campsite in the Adirondacks. One year about a month before we left one of the Pitts daughters, Edith, fell in our backyard, cutting herself on her thigh. The nasty wound became infected and, despite doctor's treatment, remained swollen, discolored and ugly when we headed for the mountains.


On those holidays we youngsters spent much of our time in or near the water and on one morning, Edith suddenly screamed and ran from the beach to our parents. Not knowing what had happened, the rest of us followed.


A black caterpillar-shaped creature had attached itself to her wound and Edith couldn't get the slippery worm off.


My father identified the animal, now swollen to the size of an inch-long cigar stub, as a leech. Dad quickly took out a match, lighted it and blew it out, then touched the hot end against the leech. It immediately let go of Edith and, much to the consternation of us children, my dad threw it back into the lake.


Although the episode made our swimming less alluring, the leech deserved not to be killed because it had effectively healed Edith's wound. Evidently it drew off the clotted blood that had delayed her recovery.


I thought of that incident when I came across John Colapinto's article, "Bloodsuckers", in a recent New Yorker magazine. He describes in that essay how leeches (and maggots as well) have become important adjuncts to modern surgery.

Colapinto quotes microsurgeon Bruce Minkin: "When you're sewing on a finger, it's relatively easy to join up the arteries that pump blood into the digit, because they're big and they've got thick walls. But it's tougher to connect the tiny veins that drain the blood away from the finger and back to the heart." If those veins aren't correctly connected, the blockage will cause the operation to fail.


It is here where the bloodsucker comes to the physician's assistance. In order to withdraw the blood it seeks -- only about two teaspoons -- the leech injects a natural anti-coagulant into the wound. This creates a kind of artificial circulation that gives the finger a chance to grow new vein attachments and the wound to heal.


Leeches have been used for medical purposes since about 1000 B.C. and their use peaked in the early 1800s when Germany alone exported about 30 million a year. Practices changed, however, and their application dropped to near zero in the first half of the 20th century. Then in 1960 two Slovenian physicians wrote about their successful use of leeches in surgery and things began to change, but very slowly.


The recent history of their use for medical purposes centers around two people. The first is Roy Sawyer, the recognized world authority on the over 650 leech species and author of a three-volume study of them. Sawyer received his doctorate from the University of Wales and stayed on there to grow leeches for medical use. His company, Biopharm, was making little headway until 1985 when the ear of a Boston five-year-old was bitten off by a dog.


And that brings us to the second person. Reconstructive plastic surgeon Joseph Upson of Boston Children's Hospital attempted to reattach the youngster's ear. Despite his twelve-hour operation, the ear began to turn blue-black from congested blood. Clearly the organ was dying.


Upson decided to try leeches. He didn't tell his colleagues -- "Are you kidding me?" he remarked later. After a frantic search he located Biopharm and Sawyer's wife drove a batch of 30 leeches to London to be flown to Boston. Within minutes of Upson's attaching the first two leeches to the boy's ear, it began to turn pink and within days the ear was completely healthy.


This was the first successful reattachment of a child's ear and the procedure gained national publicity. As a result today Biopharm distributes about 5000 leeches a month through its international centers.


Maggots represent a similar success story for surgeons. They remove dead tissue. I'll tell that one in a later column.