Zoology and Medicine Term Paper

Excerpt from Term Paper :

LEECHES: Bloodsuckers, Life-And-Limb-Savers

"Nothing works as well as leeches when we need to get blood out of a (body) part."


Blood clotting is a life-saving body process, but when it endangers life or prevents the resolution of a torn tissue, leeches can come in handy. They have shown their worth as natural blood thinners, painkillers and surgical scavengers with the anticoagulant and anesthetic properties of their saliva. These saliva components hold much promise for the "treatment of cardiological and hematological disorders" (Sohn)

These squirmy bloodsuckers, which naturally occurred in ponds in the Medieval period, were used as a panacea for a variety of diseases and disorders in early times. Surgeons and barbers employed these worms in bloodletting, believing that removing some of the blood in an affected part would cure it. It remained useful until the coming of modern medicine, which discarded it, until its reappearance in the last century as a versatile natural waste disposal surgical tool.

Today, the Hirudo Medicinalis species of leech is a reliable last resort when something is needed to overcome the clotting mechanism, something that thins the blood or decongest clots.

Using its two suckers to feed and to hang itself, the leech secretes Hirudin, an anti-coagulant and anesthetic, while it sucks blood from the host. When it has sucked enough, it just falls off from the host and leaves blood oozing fresh from its bite wound.

It works to decongest clots and to keep the blood from clotting at a period long enough to let the surgeon do his work on the patient. It is specifically useful in trauma management and surgery, such as in re-attaching severed body parts or in reconstructing a burned tissue (Polsdorfer). In general, it is of benefit to all procedures involving venous insufficiency, re-plantation surgery (where artery input can be established but not venous drainage), scalp avulsions, periorbital hematomas, heart diseases and breast surgery. Each adult leech can take in up to 15 ml of congested blood and can scavenge for half an hour. The number of leeches needed for a particular case depends on the response of the congestion to the leech.

Hirudo leeches can be bought at very minimal price from a UK distributor and then kept in an aquarium with special feeds for 18 months without a second feeding. Those which have been used should first be sedated with alcohol and then burned in an incinerator to prevent spreading the medical waste they absorbed.

There have been a few reports on complications, such as meningitis, excessive blood flow, getting lost into the body openings, allergies and psychological reactions. These, however, are readily manageable and do not outweigh the benefits of the Therapy.

Introduction. This species of parasites is proving to be an asset to man. Three cases of class 2V ring finger avulsion injuries (Sparkes et al. 1996), a nine-year-old boy's ear, ruthlessly bitten and torn by a Dalmatian, and the lives and limbs of other patients from 29 different countries have been reported as salvaged by slimy, ugly-looking and creepy leeches. The worms performed such feats by sucking gorged blood or blood clots in sufficient amounts for a few minutes or by letting blood ooze from its bite after sucking and preventing it from clotting, long enough for surgical procedures to be conducted, thus keeping the victim alive (Concannon 2000). Their saliva contains hirudin, an anti-coagulant and anesthetic that produces these effects.

Back in the 19th century, these hirudin-secreting leeches were used by surgeons and barbers in the belief that the release of some blood from the affected part would bring recovery (Concannon). So these parasites were used in treating local aches and pains, inflammation, nephritis, laryngitis, eye disorders, brain congestion, obesity and mental illness (Biopharm). Leech therapy peaked during the Napoleonic Wars until it declined with the advent of "modern medicine" (Biopharm), which viewed it as unfit. But it came back to the scene about 40 years ago as an effective agent to drain blood (Polsdorfer).

Hypothesis 1: A species of leeches is becoming a useful surgical tool in saving lives and limbs.

The Hirudo Medicinalis leech has demonstrated exceptional usefulness to medicine and health care, particularly in the plastic and reconstructive surgery fields, where torn tissues require time for delicate repair procedures (Concannon), but which is prevented by normal blood clotting. An adult leech placed on the clot will devour it up to five times its body within half an hour. When it has sucked enough, it falls off and fresh blood oozes out of the bite wound for as long as 10 hours (Did You Know?), long enough to allow the surgeon to perform procedures that will save that body part. The leeches' hirudin inhibits blood clotting while the parasites suck and likewise renders the sucked part insensitive by its anesthetic properties. An adult leech can also take in up to 15 ml of blood, which is 10 times its average body weight (Biophram). It can also survive for a full year without needing additional feeding or sucking.

With their natural capabilities, leeches are thus seen as effective tools in managing trauma - where large clots can threaten a person's survival by their size and pressure or by impeding the person's airway (Polsdorfer) - and in surgery - for their role in the reattachment of severed body parts, all conditions of venous insufficiency (Concannon), such as in pedicle or free flap surgery; in re-plantation surgery, scalp avulsions, periorbital hematomas, breast surgery or tissue reconstruction from burns. Leeches do these by sucking at the clots and restoring circulation. But they are resorted to only when all surgical means to restore blood flow are exhausted and fail (Concannon). The number of leeches used on a particular surgery depends on how the leeches affect the congestion and how long they impact it.

Hypothesis 2: It is not difficult to raise and maintain Hirudo Medicinalis leeches.

Biophram Ltd. Of UK raises such species in an aquarium, which is filled with distilled water. They are fed with special nutrients, also tailor-made to their function and in order to prevent risks of contamination. As a foremost user of leeches, Director. Concannon of the Hand and Microsurgery at the Missouri University Hospital and Clinics obtains his supply of such leeches from Biopharm Ltd. Of the United Kingdom which today sells 100,000 Hirudo Medicinalis leeches every year at less than 10 cents each. He says he keeps two or three dozens of them in his laboratory for standby purposes.

These leeches survive in the aquarium up to 18 months without another feeding. But after they are used, the leeches are sedated with alcohol and burned in the incinerator (Concannon). This is done because used leeches are full of medical waste and can spread it if they are not destroyed afterwards.

The anti-clotting usefulness of the Leech Therapy to heart diseases and nervous disorders is also currently being studied.

Hypothesis 3: There have been reported complications and objections to the surgical use of Hirudotherapy or Leech Therapy, but which are manageable.

The occurrence of Aeromonas Meningitis in a 40-year-old male patient, who received Leech Therapy after a brain tumor surgery, was reported. Leech Therapy was applied -- but without prophylactic antibiotics - to the congested graft in order to save it. (Stein). Signs of meningitis and fevers developed two days later, despite steroids. The patient was then subject to antibiotics for 21 days until he improved and was discharged from the hospital. Dr. Jay Kislak of St. Vincent's Hospital and Medical Center in New York emphasized that "prophylactic antibiotics are extremely important during leech therapy to prevent local infection as well as more serious infections, such as meningitis from the leeches' indigenous gut flora of Aeromonas species." (Stein)

Aeromonas Hydrophilia naturally occurs in the leeches' gut, which produces antibiotics…

Online Sources Used in Document:

Cite This Term Paper:

"Zoology And Medicine" (2002, April 12) Retrieved August 19, 2017, from

"Zoology And Medicine" 12 April 2002. Web.19 August. 2017. <

"Zoology And Medicine", 12 April 2002, Accessed.19 August. 2017,