Scientifically known as Hirudo Medicinalis, profiled by Niagara Leeches, medical leeches have been used by humankind since ancient times. Bloodletting dates back to ancient Egypt some 2,500 years ago. The Egyptians used leeches as a general cure all and had some success with them. The first recorded use of leeches for medicinal purposes was in 200 BC by Nicander of Colophon, a Greek physician, from eNotes.
The idea of the four humors, from Greek Medicine Net, introduced by Hippocrates, profiled by the History Learning site, suggested that when not in balance your blood, phlegm, black bile and yellow bile, was the cause of all diseases. The major treatment to regain balance was to use leeches as a remedy.
Leeches enjoyed their greatest popularity in the middle of the 19th century then, fell out of favor at the turn of the century with most physicians dismissing them as quackery. Because leeches were thought to be so helpful, their populations in the wild have fallen to endangered species levels. The International Union for Conservation of Nature and Natural Resources lists Hirudo Medicinalis as endangered.
Leeches are amphibious freshwater animals that live in small ponds that have reeds growing around the edges. They prefer shallow water because it warms up quickly to temperatures above 68 degrees Fahrenheit, which they prefer. Shallow water also provides them with their food stock, which is mostly grazing livestock. Today, most medical leeches are produced by commercially farming them. Raised in a sterile environment lowers the risk of a secondary infection from them.
Leeches attach themselves to the patient with two suckers. One end acts as an anchor while the other end sports three sets of jaws that bite through the skin leaving a Y-shaped cut. Leeches then inject a natural local anesthetic effectively numbing the area so the host does not feel the bite. Then the leech will secrete an anticoagulant called hirudin, described by Medicine Net, to keep the blood from clotting. Feeding can last up to 40 minutes ingesting up to 15ml of blood increasing their body size many times. When the leech is full, it will just drop off.
Leeches have returned from the swamps to the operating room in the last 15 years aiding surgeons with microsurgery in the reattachment of ears, fingers and circulation problems. In a reattachment, blood would pool in the severed part and have no means of returning into the system. Medical leeches remove this old blood allowing new blood to enter and regenerate new veins.
Leech therapy can last for over a week depending upon how fast the patient responds to new vein growth. Without this bloodletting by leeches, there is no chance for a severed body part to survive.
There are drawbacks to leech therapy in spite of all the good that they do. Some patients just cannot stand the thought of a bloodsucker biting into them for any reason. Patients must also take antibiotics with leech therapy because of the risk of infection. There can be excessive loss of blood and allergic reactions complicating the procedure. Leeches can also fall off the target area and reattach themselves elsewhere on the patient.
Scientists have had success in developing a “mechanical leech.” Mechanical leeches are in use today but it was Jean-Baptiste Sarlandiere, profiled by the National Center for Biotechnology Information, in 1821, who invented the first mechanical leech. The depletion of the leech population and the demand for medical leeches brought forth this revolutionary idea.
Leech therapy is widely used throughout the world and continues to help patients keep their severed body parts alive and well.