Dr. Joseph Upton published a paper in the journal of plastic and Reconstruction Surgery that made headlines in 1985 when he applied two dozen medicinal leeches to the head of a five year old boy during a successful ear reattachment operation at Boston’s Children Hospital. This 5 –year –old boy’s ear was bitten off by a dog. Ears, which have very small blood vessels, had never been successfully replanted. Dr Upton had no trouble with the boy’s arteries, but as he worked through the night reconnecting the veins, clot began to form. The use of leeches helped to release enzymes that promote blood flow and made difficult wounds heal.
Dr Andreas Michalsen and colleagues from Essen-Mitte Clinic, Germany published a paper titled “Effectiveness of leech therapy in Osteoarthritis of the knee” in the Annals of Internal Medicine. In this Study, they involved 51 patients suffering from Osteoarthritis. They divided them into two groups. One group of 24 patients with osteoarthritis, caused by wear and tear of the ageing knee, was given one shot leech therapy. Four of six leaches were allowed to attach themselves to each knee and drink blood for about an hour. 27 others with same ailment were given twice daily doses of the painkiller Diclofenac for a month. Conclusion: leech therapy was better than drug therapy!
Leech is an invertebrate belonging to the phylum Annelida. There are hundreds of species of leeches of which 15 are found to be of medicinal value. The one used in medicine is called Hirudo medicinalis. At both ends they have suckers. The anterior or oral sucker is meant for sucking the blood from the host. The posterior sucker provides a firm grip while feeding. The oral sucker has three jaws which, like a screw, can make painless wound on the host’s body. The Salivary gland produces an
Anticoagulant called Hirudin which prevents the blood from clotting, while feeding. The digestive system is modified as an spacious elastic bag to store the blood nearly 5 times its own body weight. It provides an anesthetic effect that makes the bitten host feel numb till it is attached to the body. Biologists are studying this substance this substance in order to understand its chemical nature and mechanism of action. The saliva is supposed to have many other molecules of great medicinal interest. One of them is a vasodilator, Histamine that increases the diameter of blood vessels, helping to produce blood flow. Another is an enzyme, Hyaluronidase, which breaks down hyaluronic acid, then bonding material of connective tissue, thus fostering the flow of blood and fluids from affected areas.
The benefits of uing medicinal lleches, or Hirudo medicinalis, were first recorded by Themison Lanodicea in 50 BC . His torically, they have been used for a variety of ailments that bewildered the physicians of the day . Physicians of the middle Ages relied heavily upon them. Even Napolean’s military surgeon, Francois-jospeh-Victor Broussais, was such a firm believer in the medical befits of leeches that in 1833, he had more than 40 million imported into France.
These blood suckers have played an important medical role for centuries in treating every from laryngitis to yellow fever.
Since the leeches are creepy and many patients are scared at the sight of these animals, ‘mechanical leech’ has been developed by Drs Gregory Hartig , Nadine Connor and Michael Conforti of the University of Wisconsin at Madison.
Hirudo medicinalis is rare and protected throughout much of its range and extinct from much of its former range due to over harvesting, pollution, habitat loss, and decrease in frog populations.
Attached top the body, this device delivers an anticoagulant drug, which helps decongest the blood in veins and promotes clot free circulation.
Cottler, a research associate in biomedical engineering at the university of Virginia, has also invented a mechanical leeach that he belives is superior to natures blood suckers in several ways.
Apart from acting as micro surgeons, leeches are gaining popularity as miniature pharmaceutical factories, Hirudin, which was isolated in the leech in the 1950s,has raised awareness of the leech outside the field of plastic surgery. Enzymes present in its saliva dissolve blood clots and inhibit platelet aggregation, which has let\d to the creation of drugs like Refludan (lepriudin). a recombinant protein used to treat heparin-in duced thrombocytopenia. Hirudin also shuts off the mechanism of factors VIII-mediated blood coagulating.
Genetic engineers in England have been able to clone the gene for hirudin and manufacture it using recombinant DNA technology.
To exploit leeches on a commericial scale Carolina Biological Supply Company, Burlington, N.C., has taken up Leechculture. After rearing the leeches for six months at 80degrees Fahrenheit, they are transferred to a room chilled to a growth-slowing 45degrees Fahrenheit., where they can live for a year without food.
Hungry leeches work well on patients. Once they have finished dining on a patient, they are disposed off like medical waste.
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