Preparation materials for practical lessons ¹8

Leech Therapy

History of Leech Therapy

The History of the Leech in Medicine

Medicinal leeches are as old as the Pyramids. Literally. Records indicate that Egyptians used leech therapy over 3,500 years ago and leeches (often mistakenly credited as cobras) are included in the hieroglyphics painted on the walls. Leech therapy was used to treat a wide range of conditions, from headaches to hemorrhoids. 

Bloodletting is one of the oldest medical practices, having been practiced since ancient times, including the Mesopotamians, the Greeks, the Mayans, and the Aztecs. In Greece, bloodletting was standard practice around the time of Hippocrates and Herophilos.

 

Herophilos (335-280 BC) was a Greek physician who was the first scientist to systematically perform scientific dissections of human cadavers and is deemed to be the first anatomist. Hippocrates of Cos (460BC-370BC) was also a Greek physician and is referred to as the “father of medicine”. He was the first physician to reject superstitions, legends and beliefs that credited supernatural or divine forces causing illness.

Both physicians used medicinal leeches, amongst other methods, for blood letting to remove blood from a patient to “balance the humours”. The four humours of ancient medical philosophy were blood, phlegm, black bile and yellow bile. The belief at the time was that these four humours must be kept in balance in order for the human body to function properly. Any disease or illness was thought to be a result of an imbalance of these humours. The dominant humour was believed to be blood.

However it was Aelius Galenus (AD 129 – 200), a prominent physician and philosopher and the most accomplished medical researcher of the Roman era who practiced blood letting extensively and introduced blood letting to Rome. His theories dominated and influenced Western medical science for well over a millennium. Of the four humours, Galen believed that blood was the dominant humour and the one in most need of control. Romans were the first to use the HIRUDO name for leeches.

 

Leech therapy or HIRUDOTHERAPY survived the fall of the Western Roman Empire and remained popular throughout the Middle Ages. Over the centuries it remained an integral part of treating disease and illnesses all around the world. Bloodletting in its various forms was especially popular in the young United States of America. Benjamin Rush (a signatory of the Declaration of Independence) saw the state of the arteries as the key to disease, recommending higher than ever levels of bloodletting. Which were way too high, indeed!

 

As a lecturer at the Royal College of Physicians would state in 1840, “blood-letting is a remedy which, when judiciously employed, is hardly possible to estimate too highly”.

Indeed, by the mid 1800’s the demand for leeches was so high that the French imported about forty million leeches a year for medical purposes, and in the next decade, England imported six million leeches a year from France alone, since the leech production from their own farm near Oxford were insufficient. And it wasn’t just Europe – there was an explosion in the use of leeches in Asia and the Middle East.

 

Many abandoned leeches with the advent of antibiotics in the 1930’s. However bloodletting still persisted and was even recommended by Sir William Osler in the 1923 edition of his textbook  The Principles and Practice of Medicine. In the second half of the 20th century leeches became an important role in medical practice and leeches are now used extensively by reconstructive surgeon’s needing to remove stagnant blood from a flap or reattached limb, and as well, in non-invasive leech-therapy treatments outside of hospital facilities.

 

In the Act of June 28, 2004, the Food and Drug administration (FDA) cleared for the first time the commercial marketing of Medicinal Leeches for medicinal purposes and determined that leeches are medical devices because they meet the definition of a medical device. 

 

Medical research and the use of leeches never stopped in some parts of the world, especially in Germany and Russia. So it is little wonder that both countries achieved the highest level in overall research on medicinal leeches and , Russia, became a biggest producer of Hirudo Medicinalis in the World. 

 

Leeches and their History      

 

 For over 4000 years, the leech has been a familiar remedy, with Greek and Roman physicians praising the application of this clever invertebrate.

 In the 19th century leeches were enjoying a golden age. Millions were raised for medical use as their fame as a cure-all ensued. The mid 1800s saw their constant use for local bloodletting. Druggists administered thousands of leeches to patients with anything from gumboils to facial discolouration. Leeches were applied to the mouth and inside of the throat using a leech-glass, although patients frequently swallowed them. Patients were relieved only with a salty drink of water or perhaps the most popular cure-all of the day, a couple of glasses of wine. Sometimes the leech would not drink and then had to be encouraged by some blood or cream smeared at the puncture site or bathed in a warm glass of beer until ready.

 Once sucking, an average leech would drink blood weighing as much as itself in about 15 minutes and consume between 2.5-5.5 grams of blood (half a teaspoon). If the bite failed to stop bleeding after the leech was removed then vinegar, silver nitrate and hot wires were applied.

 

 Apart from using the English and Scottish leeches, huge numbers were imported from France, Hungary, the Ukraine, Turkey, Rumania, Russia, Egypt and Algeria. In 1846 in France alone, 30 million leeches were used. Hospitals in both London and Paris required 13 million between them for that single year. America produced their own leeches and one farm sold over a thousand per day. Leeches were also caught from the wild by many interesting ways, including men bathing a muddy ditch or in a stream with a glass of pig blood, rolling their trousers up and wading into the water. Here they would wait patiently for leeches to adhere themselves to their legs. After a while, back on land the feeding leeches would be stripped off and sold to leech dealers. The leech industry began its decline due to the over collection of the animal and its discredit by the medical profession. By the end of the 19th century the golden age of the leech had passed.

Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes, such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways. For example, leeches do not have bristles and the external segmentation of their bodies does not correspond with the internal segmentation of their organs. Their bodies are much more solid as the spaces in their coelom are dense with connective tissues. They also have two suckers, one at each end.

 

The majority of leeches live in freshwater environments, while some species can be found in terrestrial and marine environments, as well. Most leeches are hematophagous, as they are predominantly blood suckers that feed on blood from vertebrate and invertebrate animals.Almost 700 species of leeches are currently recognized, of which some 100 are marine, 90 terrestrial and the remainder freshwater taxa.

 

Leeches, such as the Hirudo medicinalis, have been historically used in medicine to remove blood from patients. The practice of leeching can be traced to ancient India and Greece, and continued well into the 18th and 19th centuries in both Europe and North America. In modern times, the practice of leeching is much rarer and has been replaced by other contemporary uses of leeches, such as the reattachment of body parts and reconstructive and plastic surgeries  and, in Germany, treating osteoarthritis.

 Today leeches are bred in captivity in many institutions including Bristol Zoo Gardens. Leeches have found new fame in microsurgery, where doctors require the precision of the leech to drain congested blood from wounded sites. Plastic surgeons are particularly grateful for the contribution made by the leech, due to their use in the treatment of difficult grafts and reconstructive surgery. The nervous system of the leech is very similar to the human nervous system and is an enormous benefit to researchers in their quest for the answers to human problems.

Today the rest of the world is catching on as leeches are on the cusp of not only enjoying a revival for known health benefits, but there are constant new discoveries based on thorough medical research about positive effects of the substances produced by medicinal leeches.

Leeches are presumed to have evolved from certain Oligochaeta, most of which feed on detritus. However, some species in the Lumbriculidae are predatory and have similar adaptations as found in leeches. As a consequence, the systematics and taxonomy of leeches is in need of review. While leeches form a clade, the remaining oligochaetes are not their sister taxon, but in a diverse paraphyletic group containing some lineages that are closely related to leeches, and others that are far more distant.

 

There is some dispute as to whether Hirudinea should be a class itself, or a subclass of the Clitellata. The resolution mainly depends on the eventual fate of the oligochaetes, which as noted above, do not form a natural group as traditionally circumscribed. Another possibility would be to include the leeches in the taxon Oligochaeta, which would then be ranked as a class and contain most of the clitellates. The Branchiobdellida are leechlike clitellates that were formerly included in the Hirudinea, but are just really close relatives.

 

The more primitive Acanthobdellidea are often included with the leeches, but some authors treat them as a separate clitellate group. True leeches of the infraclass Euhirudinea have both anterior and posterior suckers. They are divided into two groups: Arhynchobdellida and Rhynchobdellida

Rhynchobdellida are "jawless" leeches, armed with a muscular, straw-like proboscis puncturing organ in a retractable sheath. The Rhynchobdellae consist of two families:

Glossiphoniidae are flattened leeches with poorly defined anterior suckers.

Piscicolida have cylindrical bodies and usually well-marked, bell-shaped, anterior suckers. The Glossiphoniidae live in freshwater habitats; the Pisciolidae are found in seawater habitats.

Arhynchobdellida lack a proboscis and may or may not have jaws armed with teeth. Arhynchobellids are divided into two orders:

Gnathobdela: In this order of "jawed" leeches, armed with teeth, is found the quintessential leech: the European medical (bloodsucking) leech, Hirudo medicinalis. It has a tripartite jaw filled with hundreds of tiny, sharp teeth. The incision mark left on the skin by the European medical leech is an inverted Y inside a circle. Its North American counterpart is Macrobdela decora, a much less efficient medical leech. Within this order, the family Hirudidae is characterized by aquatic leeches and the family Haemadipsidae by terrestrial leeches. In the latter are Haemadipsa sylvestris, the Indian leech and Haemadipsa zeylanica (yamabiru), the Japanese mountain or land leech.

Pharyngobdella: These so-called worm-leeches consist of freshwater or amphibious leeches that have lost the ability to penetrate a host's tissue and suck blood. They are carnivorous and equipped with a relatively large, toothless mouth to ingest worms or insect larvae, which are swallowed whole.

 The Pharyngobdella have six to eight pairs of eyes, as compared with five pairs in Gnathobdelliform leeches, and include three related families. The Erpobdellidae are some species from freshwater habitats.

Anatomy and physiology

 

 The leech and its nervous system

 

 The number and position of eyes are essential for distinguishing the leech species.

 

Like other annelids, the leech is a segmented animal. But unlike other annelids, there is no correspondence between the external segmentation of a leech's body surface with the segmentation of its internal organs. The body surface of the animal can be divided into 102 annuli, whereas its internal structures are divided into 32 segments. Of the 32 segments within the body, the first four anterior segments are designated as head segments, which include an anterior brain and sucker. This is followed by 21 midbody segments, which include 21 neuronal ganglia, two reproductive organs, and 9 pairs of testes. Finally, the last seven segments are fused to form the animal's tail sucker, as well as its posterior brain. The leech also has 32 brains because a brain segment is located in each segmentation of the body.

Reproduction and development

 

Leeches are hermaphrodites, meaning each has both female and male reproductive organs (ovaries and testes, respectively). Leeches reproduce by reciprocal fertilization, and sperm transfer occurs during copulation. Similar to the earthworms, leeches also use a clitellum to hold their eggs and secrete the cocoon.

During reproduction, leeches use hyperdermic injection of their sperm. They use a spermatophore, which is a structure containing the sperm. Once next to each other, leeches will line up with one's anterior side opposite the other's posterior. The leech then shoots the spermatophore into the clitellur region of the opposing leech, where its sperm will make its way to the female reproductive parts.

 

The embryonic development of the la occurs as a series of stages. During stage 1, the first cleavage occurs, which gives rise to an AB and a CD blastomere, and is in the interphase of this cell division when a yolk-free cytoplasm called teloplasm is formed. The teloplasm is known to be a determinant for the specification of the D cell fate. In stage 3, during the second cleavage, an unequal division occurs in the CD blastomere. As a consequence, it creates a large D cell on the left and a smaller C cell to the right. This unequal division process is dependent on actinomycin, and by the end of stage 3 the AB cell divides. On stage 4 of development, the micromeres and teloblast stem cells are formed and subsequently, the D quadrant divides to form the DM and the DNOPQ teloblast precursor cells. By the end stage 6, the zygote contains a set of 25 micromeres, 3 macromeres (A, B and C) and 10 teloblasts derived from the D quadrant.

 

The teloblasts are pairs of five different types (M, N, O, P, and Q) of embryonic stem cells that form segmented columns of cells (germinal band) in the surface of the embryo.The M-derived cells make mesoderm and some small set of neurons, N results in neural tissues and some ventral ectoderm, Q contributes to the dorsal ectoderm and O and P in the leech are equipotent cells (same developmental potential) that produce lateral ectoderm; however the difference between the two of them is that P creates bigger batches of dorsolateral epidermis than O. The sludgeworm Tubifex, unlike the leech, specifies the O and P lineages early in development and therefore, these two cells are not equipotent. Each segment of the body of the leech is generated from one M, O, P cell types and two N and two Q cells types.

 

The ectoderm and mesoderm of the body trunk are exclusively derived from the teloblast cells in a region called the posterior progress zone.The head of the leech that comes from an unsegmented region, is formed by the first set of micromeres derived from A, B, C and D cells, keeping the bilateral symmetry between the AD and BC cells.

 

 Mouthparts and sucker

 

In most blood-sucking leeches the digestive system starts with the jaws, three blades set at an angle to each other. In feeding they slice their way through the skin of the host, leaving a Y-shaped incision. Behind the blades is the mouth, located ventrally at the anterior end of the body. It leads successively into the pharynx, then the esophagus, the crop, the gizzard, and the intestinum, which ends at the posterior sucker. The crop is a distension of the alimentary canal that functions as an expandable storage compartment. In the crop, some blood-sucking species of leech can store up to five times the body mass of blood. The leech produces an anticoagulant that prevents the stored blood from clotting, plus other agents that inhibit microbial decay of the blood. These measures are so effective that a mature medicinal leech does not need to feed more than twice a year. Possibly as an adaptation, its digestive process is extremely slow.

 

The bodies of predatory leeches are similar, though instead of jaws many have a protrusible proboscis, which for most of the time they keep retracted into the mouth. Such leeches often are ambush predators that lie in wait till they can strike prey with the proboscises in a spear-like fashion. Some kinds that live on small invertebrates or detritus have neither proboscis nor jaws, but simply engulf their food with the mouth.

 

Bacteria in the gut were long thought to carry on digestion for the leech, instead of endogenous enzymes that are very low or absent in the intestine. As discovered relatively recently, all leech species studied do produce endogenous intestinal exopeptidases, which can unlink free terminal-end amino acids, one monomer at a time from a gradually unwinding and degrading protein polymer. However, unzipping of the protein can start from either the amino (tail) or carboxyl (head) terminal-end of the protein molecule. The leech exopeptidases (arylamidases), possibly aided by proteases from endosymbiotic bacteria in the intestine, starting from the tail or amino end, slowly but progressively removing many hundreds of individual terminal amino acids for resynthesis into proteins that constitute the leech. Since leeches lack endopeptidases, the mechanism of protein digestion cannot follow the same sequence as it would in all other animals in which exopeptidases act sequentially on peptides produced by the action of endopeptidases. Exopeptidases are especially prominent in the common North American worm-leech Erpobdella punctata. This evolutionary choice of exopeptic digestion in Hirudinea distinguishes these carnivorous clitellates from Oligochaeta.

 

Deficiency of digestive enzymes (except exopeptidases), but, more importantly, deficiency of vitamins, B complex for example, in leeches is compensated for by enzymes and vitamins produced by endosymbiotic microflora. In Hirudo medicinalis, these supplementary factors are produced by an obligatory symbiotic relationship with two bacterial species, Aeromonas veronii and a still-uncharacterized Rikenella species. Nonbloodsucking leeches, such as Erpobdella punctata, are host to three bacterial symbionts, Pseudomonas, Aeromonas, and Klebsiella spp. (a slime producer). The bacteria are passed from parent to offspring in the cocoon as it is formed.

Behavior

 

 Leech climbing a door by Lake Leake, Tasmania

 

Leeches are able to display a variety of behaviors that allow them to explore their environments and feed on their hosts. Exploratory behavior includes head movements and body waving.

Feeding

 

 Leech attacking a slug

 

Most leech species do not feed on human blood, but instead prey on small invertebrates, which they eat whole. To feed on their hosts, leeches use their anterior suckers to connect to hosts for feeding. Once attached, leeches use a combination of mucus and suction to stay attached and secrete an anticoagulant enzyme, hirudin, into the hosts' blood streams. Though certain species of leeches feed on blood, not all species can bite; 90% of them feed solely on decomposing bodies and open wounds of amphibians, reptiles, waterfowl, fish, and mammals (including humans). A leech attaches itself when it bites, and it will stay attached until it becomes full, at which point it falls off to digest. Due to the hirudin secreted, bites may bleed more than a normal wound after the leech is removed.

 

Leech saliva are commonly believed to contain anesthetic compounds to numb the bite area, but this has never been proven. Although morphine-like substances have been found in leeches, they have been found in the neural tissues, not the salivary tissues. They are used by the leeches in modulating their own immunocytes and not for anesthesizing bite areas on their hosts. Depending on the species and size, leech bites can be barely noticeable or they can be fairly painful.

Leeches normally carry parasites in their digestive tracts, which cannot survive in humans and do not pose a threat. However, bacteria, viruses, and parasites from previous blood sources can survive within a leech for months, but only a few cases of leeches transmitting pathogens to humans have been reported. A study found both HIV and hepatitis B in African leeches from Cameroon.

Removal and treatment

 

 A land leech can be removed by hand, since they do not burrow into the skin or leave the head in the wound. A sore develops and lasts for about a week. Grande Ronde River, Oregon (U.S.)

 

One recommended method of removal is using a fingernail or other flat, blunt object to break the seal of the oral sucker at the anterior end of the leech, repeating with the posterior end, then flicking the leech away. As the fingernail is pushed along the person's skin against the leech, the suction of the sucker's seal is broken, at which point the leech will detach its jaws.

 Common, but medically inadvisable, techniques to remove a leech are to apply a flame, a lit cigarette, salt, soap, or a chemical such as alcohol, vinegar, lemon juice, insect repellent, heat rub, or certain carbonated drinks. These will cause the leech to quickly detach; however, it will also regurgitate its stomach contents into the wound. The vomit may carry disease, and thus increase the risk of infection.

 

An externally attached leech will detach and fall off on its own when it is satiated on blood, which may be anywhere from 20 minutes to two hours or more. After feeding, the leech will detach and depart. Internal attachments, such as inside the nasal passage or vaginal attachments, are more likely to require medical intervention.

 

After removal or detachment, the wound should be cleaned with soap and water, and bandaged. Bleeding may continue for some time, due to the leech's hirudin. Bleeding time will vary, with location, from a few hours to three days. This is a function of the hirudin and other compounds that reduce the surface tension of the blood. Anticlotting medications also affect the bleeding time. Applying pressure can reduce bleeding, although blood loss from a single bite is not dangerous. The wound normally itches as it heals, but should not be scratched, as this may complicate healing and introduce other infections. An antihistamine can reduce itching, and applying a cold pack can reduce pain or swelling.

 

Some people suffer severe allergic or anaphylactic reactions from leech bites and require urgent medical care. Symptoms include red blotches or an itchy rash over the body, swelling around the lips or eyes, feeling faint or dizzy, and difficulty breathing.

Medicinal use of leeches

Further information: Hirudotherapy

 

The European medical leech Hirudo medicinalis and some congeners, as well as some other species, have been used for clinical bloodletting for thousands of years. The use of leeches in medicine dates as far back as 2,500 years ago, when they were used for bloodletting in ancient India. Leech therapy is explained in ancient Ayurvedic texts. Many ancient civilizations practiced bloodletting, including Indian and Greek civilizations. In ancient Greek history, bloodletting was practiced according to the humoral theory, which proposed that, when the four humors, blood, phlegm, black and yellow bile in the human body were in balance, good health was guaranteed. An imbalance in the proportions of these humors was believed to be the cause of ill health. Records of this theory were found in the Greek philosopher Hippocrates' collection in the fifth century BC. Bloodletting using leeches was one method used by physicians to balance the humors and to rid the body of the plethora.

 

The use of leeches in modern medicine made its comeback in the 1980s after years of decline, with the advent of microsurgeries, such as plastic and reconstructive surgeries. In operations such as these, problematic venous congestion can arise due to inefficient venous drainage. Sometimes, because of the technical difficulties in forming an anastomosis of a vein, no attempt is made to reattach a venous supply to a flap at all. This condition is known as venous insufficiency. If this congestion is not cleared up quickly, the blood will clot, arteries that bring the tissues their necessary nourishment will become plugged, and the tissues will die. To prevent this, leeches are applied to a congested flap, and a certain amount of excess blood is consumed before the leech falls away. The wound will also continue to bleed for a while due to the anticoagulant hirudin in the leeches' saliva. The combined effect is to reduce the swelling in the tissues and to promote healing by allowing fresh, oxygenated blood to reach the area.

The active anticoagulant component of leech saliva is a small protein, hirudin. Discovery and isolation of this protein led to a method of producing it by recombinant technology. Recombinant hirudin is available to physicians as an intravenous anticoagulant preparation for injection, particularly useful for patients who are allergic to or cannot tolerate heparin.

The Benefits of Leech Therapy and its Effects

 

Yes, leeches can be thought of as slimy and unattractive creatures, but ugly or not, they do serve a lot of medical purposes when it comes to us, humans.

 

Since ancient times, leeches were used to treat many illnesses and disease through bloodletting, a method where blood was drawn out in the hope that removing impure blood would heal the body. Believe it or not, leech therapy is sometimes the best alternative in treating illnesses, and even surpasses pharmacological treatments. Because of its healing effects to the human body, this traditional method of curing diseases is still thriving today.

 

 Leeches shown during treatment of

 varied conditions

 

 The Benefits of Leech Therapy

 

There are more than 600 species of leeches that have been identified, but only 15 of the species are used medically, so they are given a class of their own. They are classified as Hirudo Medicinalis or medicinal leeches.

Leech therapy has been used and is still in use for many diseases of the body. They are used to treat arthritis and other inflammatory processes. It is perfect for those with vascular (arterial and venous diseases), heart (ischemic diseases and hypertension), and lung problems (bronchitis and bronchial asthma). The medicinal leeches can also help in patients with pneumonia. The GI or gastrointestinal tract can also benefit from leech therapy, especially those who suffer from hepatitis, stomach ulcers, and pancreatitis, among others. Likewise, individuals with problems in their genitourinary system and gynecological disorders will also benefit greatly from leech therapy. Skin diseases like psoriasis, herpes, and eczema can also be treated with leech therapy. Other problems known to benefit from leech therapy are the eyes (example is glaucoma) and the brain (for infantile cerebral palsy).

 

But how exactly do leeches treat these many illnesses and diseases?

 

 

 Leeches shown during treatment of

 varied conditions

Anticoagulating Effects of Leeches

 

The leech’s saliva contains enzymes and compounds that act as an anticoagulation agent. The most prominent of these anticoagulation agents is hirudin, which binds itself to thrombins, thus, effectively inhibiting coagulation of the blood.

 

Another compound that prevents coagulation is calin. This, on the other hand, works as an anticoagulant by prohibiting the von Willebrand factor to bind itself to collagen, and it is also an effective inhibitor of platelet aggregation caused by collagen.

 

The saliva of the leeches also contains Factor Xa inhibitor which also blocks the action of the coagulation factor Xa.

 Clot Dissolving Effects of Leeches

 

The action of destabilase is to break up any fibrins that have formed. It also has a thrombolytic effect, which can also dissolve clots of blood that have formed.

 

 Blood expelled after different treatments

 

Anti-inflammatory Effects of Leeches

 

Bdellins is a compound in the leech’s saliva that acts as an anti-inflammatory agent by inhibiting trypsin as well as plasmin. It also inhibits the action of the acrosin. Another anti-inflammatory agent is the eglins.

 Vasodilating Effects of Leeches

 

There are three compounds in the leeches’ saliva that act as a vasodilator agent, and they are the histamine-like substances, the acetylcholine, and the carboxypeptidase A inhibitors. All these act to widen the vessels, thus, causing inflow of blood to the site.

Bacteriostatic and Anesthetic Effects of Leeches

 

The saliva of leeches also contains anesthetic substances which deaden pain on the site and also bacteria-inhibiting substances which inhibit the growth of bacteria.

Overall Effects to the Human Body

 

 

 Medicinal leech grown to 13cm

after treatment

 

Once the leeches attach themselves to the skin of the patient and start sucking blood, the saliva enters the puncture site and along with it the enzymes and compounds responsible for all these positive effects. Working together, they act to cure the disease present in the individual. Because of anticoagulation agents, the blood becomes thinner, allowing it to flow freely through the vessels. The anti-clotting agents also dissolve clots found in the vessels, eliminating the risk of them traveling to other parts of the body and blocking an artery or vein. The vasodilating agents help widen the vessel walls by dilating them, and this causes the blood to flow unimpeded, too.

 

Patients who suffer from pain and inflammation will feel relief from the anti-inflammatory and anesthetic effects of the leech's saliva.

 

In the long run, leech therapy also helps to normalize the blood pressure of hypertensive individuals as well as lessen their risk of suffering from stroke and heart attacks. Blood circulation is also improved with leech therapy and it helps with the healing process of wounds, as well as wounds and lesions caused by diabetes. There is also a noticeable boost in the immune system's function due to bacteriostatic agents.

Contraindication to Leech Therapy

 

Leech therapy is contraindicated to patients with HIV and AIDS. It is also not recommended to patients who are on immunosuppressive drugs. Leech therapy puts these patients at risk for bacterial sepsis, thus, worsening their conditions.

Leech therapy is the use of leeches in the treatment of medical conditions. Leeches are carnivorous or bloodsucking aquatic or terrestrial worms typically having two "suckers," one at each end. The back end suction cup helps the leech to ambulate on dry surfaces, and to attach to its host; the front-end suction cup also contains the mouth with three sharp jaws that leave a Y-shaped bite. The medicinal leech lives in clean waters. Leeches swim free in the water, with an undulating motion. When attached to its host for feeding, the leech remains in place for 30 minutes to 6 hours or more, as it fills with blood. During feeding, leeches can suck 5-15mL of blood, which is several times its own body weight.

 

The first medical use of leeches is thought to have taken place in ancient India in 1000 BC. The ancient Indians used leeches to treat a wide range of conditions including headaches, ear infections and hemorrhoids. In pre-scientific medicine, the medicinal leech was used to remove blood from a patient as part of a process to "balance the humors" that, according to Hippocrates, must be kept in balance in order for the human body to function properly. The four humors of ancient medical philosophy were blood, phlegm, black bile, and yellow bile. According to this theory, any sickness that caused the subject's skin to become red (e.g. fever and inflammation), must have arisen from too much blood in the body. Similarly, any person whose behavior was strident and sanguine, meaning animated, was thought to be suffering from an excess of blood. By the mid-1800s, the demand for leeches in Europe was so large that the exporter in Germany shipped over 30 million leeches a year.

 

Leeches (Hirudo medicinalis) historically used to remove "bad blood," are now used extensively by reconstructive surgeons needing to remove stagnant blood from a flap or reattached limb. When the venous blood does not return to the heart, it pools in the wounded area, increasing pressure and preventing fresh arterial blood from entering the area with oxygen and nutrients. The venous blood must be removed and the pressure must be reduced in order to save the flap or limb. The leech is able to do this exceptionally well, because its saliva contains biochemicals including vasodilators, anticoagulants, and anesthetics.

 

Perhaps the best-known advocate of medical leeches today is Roy Sawyer, an American researcher. Several decades ago, he noted the potential benefits of leech therapy and started one of the world's first modern leech farms. Today, the company BioPharm, which is based in Britain, provides tens of thousands of leeches every year to hospitals in dozens of countries.

 

In 2001, the mechanical leech was developed, in part by Nadine Connor, a University of Wisconsin at Madison scientist. The device, which looks a little like a small bottle attached to a suction cup, delivers an anti-clotting drug, similar to that in a leech's saliva, to damaged tissue and then gently sucks out as much blood as needed. Unlike real leeches, the mechanical version is insatiable and can remove as much blood as doctors think is necessary.

 

Leech therapy is the use of leeches in the treatment of medical conditions. Leeches are carnivorous or bloodsucking aquatic or terrestrial worms typically having two "suckers," one at each end. The back end suction cup helps the leech to ambulate on dry surfaces, and to attach to its host; the front-end suction cup also contains the mouth with three sharp jaws that leave a Y-shaped bite. The medicinal leech lives in clean waters. Leeches swim free in the water, with an undulating motion. When attached to its host for feeding, the leech remains in place for 30 minutes to 6 hours or more, as it fills with blood. During feeding, leeches can suck 5-15mL of blood, which is several times its own body weight.

 

The first medical use of leeches is thought to have taken place in ancient India in 1000 BC. The ancient Indians used leeches to treat a wide range of conditions including headaches, ear infections and hemorrhoids. In pre-scientific medicine, the medicinal leech was used to remove blood from a patient as part of a process to "balance the humors" that, according to Hippocrates, must be kept in balance in order for the human body to function properly. The four humors of ancient medical philosophy were blood, phlegm, black bile, and yellow bile. According to this theory, any sickness that caused the subject's skin to become red (e.g. fever and inflammation), must have arisen from too much blood in the body. Similarly, any person whose behavior was strident and sanguine, meaning animated, was thought to be suffering from an excess of blood. By the mid-1800s, the demand for leeches in Europe was so large that the exporter in Germany shipped over 30 million leeches a year.

 

Leeches (Hirudo medicinalis) historically used to remove "bad blood," are now used extensively by reconstructive surgeons needing to remove stagnant blood from a flap or reattached limb. When the venous blood does not return to the heart, it pools in the wounded area, increasing pressure and preventing fresh arterial blood from entering the area with oxygen and nutrients. The venous blood must be removed and the pressure must be reduced in order to save the flap or limb. The leech is able to do this exceptionally well, because its saliva contains biochemicals including vasodilators, anticoagulants, and anesthetics.

 

Perhaps the best-known advocate of medical leeches today is Roy Sawyer, an American researcher. Several decades ago, he noted the potential benefits of leech therapy and started one of the world's first modern leech farms. Today, the company BioPharm, which is based in Britain, provides tens of thousands of leeches every year to hospitals in dozens of countries.

 

In 2001, the mechanical leech was developed, in part by Nadine Connor, a University of Wisconsin at Madison scientist. The device, which looks a little like a small bottle attached to a suction cup, delivers an anti-clotting drug, similar to that in a leech's saliva, to damaged tissue and then gently sucks out as much blood as needed. Unlike real leeches, the mechanical version is insatiable and can remove as much blood as doctors think is necessary.

Technique

 

The application of leeches to the patient is relatively simple, but does require application by a qualified healthcare professional. As few as one, or as many as six or more leeches may be required for a wound, depending upon its size and its clinical response. The greatest number of leeches should be applied by the healthcare provider to the area of maximal venous congestion.

 

The patient's skin is typically cleaned thoroughly with soap and water, and then rinsed with distilled, non-chlorinated water. A gauze barrier around the area intended for the leech is used to prevent the leech from wandering away from the site where its attachment is desired.

 

Once the leech is attached, it will likely remain safely in place until fully distended. The site should be checked continuously to insure that the leech has not moved. The leech will let go of the patient (host) when it is finished (usually within an hour).

 

If the leech is reluctant to bite, it might be necessary to entice it with a tiny droplet of blood, drawn from the wound site with a needle prick.

 

Theory/evidence

 

The benefits of leech therapy are due, in large part, to the anticoagulant effects ("blood thinning"), vasodilatory effects, and anesthetic effects of the biochemicals contained in leech saliva, as well as the physical effects of blood letting (phlebotomy). Hirudin, a potent anticoagulant in leech saliva, inhibits the conversion of fibrinogen to fibrin, preventing blood from clotting. Indeed, a wound may continue to bleed for many hours after the leech has already detached due to the anticoagulant effect of hirudin. Many recently developed prescription drugs used for similar conditions were designed based on the mechanism of action of leeches.

 

Leeches are used to assist in the reattachment of severed body parts such as fingers, hands, toes, legs, ears and noses. Leeches are used to help with venous insufficiency when there is sufficient arterial flow when reattaching severed body parts.

 

Today leeches are also used to drain blood from swollen faces, limbs and digits (fingers and toes) after reconstructive surgery. They are especially useful when reattaching small body parts that have many small blood vessels. Leeches are used to prevent the clotting of blood in these small veins. Leeches are gently placed in the area needed by a qualified healthcare provider, and allowed to attach and engorge for the next 6-12 hours, after which they will release. The entire course of treatment may require one to 6 treatments or more, depending upon the goals and rate of response.

 

The leech will withdraw approximately 5mL (one teaspoon) of blood. Further therapeutic benefit of leech therapy comes after the leech is removed, during which up to 50mL of blood will continue to ooze, for up to 48 hours. More leeches attached to the site will result in the removal of more blood. After 3-7 days, the veins have usually reconnected themselves such that the blood is no longer pooling in the limb. Normal color and pressure should return to the area, as arterial blood circulates easily in the damaged zone. By that time, the wound will be able to heal, without further phlebotomy (removing blood).

 

Evidence: In 1998, Bapat et al. investigated the use of medicinal leeches in the treatment of complicated varicose veins and found that medicinal leeches aided ulcer healing and could be used as an adjunct in the management of complicated varicose veins due to their blood sucking ability. In a randomized controlled trial in 2003, Michalsen et al. found that medicinal leech therapy was effective in relieving symptoms in patients with osteoarthritis of the knee. Based on clinical use, the leech may also be of value in those performing microsurgery who are faced with the difficulties of reattaching minute veins.

Safety

 

Delayed infection, occurring a few days after leech therapy has been reported and caution is advised.

 

Optimal care is recommended when applying leeches because their use can be complicated by serious bacterial infections.

 

Leech therapy may interact with antibiotic therapy such as trimethoprim and sulfamethoxazole (Cotrim forte) and may precipitate allergic reactions. In one case study, Beer et al. reported an allergic reaction that developed after four days of leech therapy and antibiotic use, which was reversed using systemic doses of glucocorticoids. This case was not considered typical.

Once abundant in Europe from Ireland to the Ural mountains (western Russia) and from southern Scandinavia to the Mediterranean. It is still present in one or more localities in 24 European countries although it is threatened in at least 12 of these. Its status is uncertain in Portugal, Sicily and Turkey and it has been extinct in Ireland for at least 100 years. It was imported into North America for medicinal purposes but no recent records have shown its presence in the wild. Present in small numbers in Britain particularly in rural areas such as New Forest, the Lake District, South Wales, Anglesey and the west of Scotland. The largest population in Britain is thought to be in Dungeness, Kent where a mark-release-recapture experiment indicated a self-sustaining population of 6,000 - 12,000 leeches in 1985.

 Ecological and Habitat Requirements

Hirudo medicinalis typical habitats consist of shallow, eutrophic ponds or lakes with dense stands of macrophytes and high summer temperatures. High temperature requirements have important implications for the distribution of the medicinal leech, for example, it cannot survive in many lakes and most of the tarns in the Lake District due to the relatively low temperatures. The average temperatures for 10%, 50% and 90% activity in the medicinal leech are 11.9˚C, 19.0˚C and 22.9˚C respectively. The minimum temperature threshold for swimming activity is 5-9˚C. In a temperature gradient of 7-43˚C, studies have shown that 21˚C is the preferred temperature. The optimum temperature ranges for growth and breeding are 22-25˚C and 25.5-27.5˚C respectively with the upper lethal range being 39-43.5˚C.

 Food and Feeding

H. medicinalis is the only species known to attack humans. Like other Gnathobdellid leeches, it has a short muscular pharynx usually with toothed jaws. It feeds almost exclusively on the blood of mammals but other hosts include amphibians and small fish. A single leech can take two to five times its own weight of blood in a meal, which is digested slowly over several months. For example, a leech weighing 128mg dry weight took 640mg dry weight of blood in one meal, took about 200 days to digest this meal and survived for a further 100 days without another meal. Therefore, one meal can sustain a leech for a year. The bacterium Aeromonas hydrophila is a normal symbiont in the gut of medicinal leeches which produces enzymes necessary to digest the blood ingested by the leech. Although it takes only about half an hour for a leech to become satiated on a mammalian host, the host can move a considerable distance in this time and therefore it is thought that in nature, leeches frequently detach from the host long before they are satiated to ensure they do not become isolated from their habitat.

 Life Cycle Summary

Leeches are protandrous hermaphrodites and tend to cross fertilise by taking up a head-to-tail position with another leech. H. medicinalis has an eversible penis, a single male and a single female pore, a single pair of ovaries and between 10 and 100 pairs of testes. Matings occur in summer and sperm can be stored so there can be a delay of 1-9 months between copulation and cocoon deposition. Segments near the middle of the body are modified in mature worms to form a clitellum that secretes a cocoon for the eggs. Each sclerotized cocoon is about 10mm long, either oval or spherical in shape with the wall consisting of an inner smooth layer and an outer spongy layer and contains between 5 and 15 eggs. They are laid in a damp place just above the water line on the shore or bank of lakes or ponds. Cocoons are normally found in July and August and hatching time varies from 4 to 10 weeks depending on temperature. In laboratory conditions, H. medicinalis lay 1-7 cocoons in which 3-30 eggs develop and each individual can produce 2 broods per year under optimum conditions. Newly hatched leeches weigh approximately 0.12-0.18g live weight and this increases to 0.5-0.6g by end of first year, about 1.4g in second year and 2.4g in third year. It is thought that they take at least 2 years to reach sexual maturity in the field and slow-growing leeches may not breed until 3 or 4 years of age. 

 Life Stages

 

Life Stage: Adult

 

Definitive Host: Mammals (including humans), amphibians and fish.

Site Within Host: Ectoparasitic.

 

Host Habitat: Freshwater ponds and lakes.

 

Free Living Environment: Freshwater ponds and lakes (also comes onto the shore to lay cocoons containing eggs).

 

Reproduction Capacity: Sexually mature.

 

Morphology: Red-yellow longitudinal stripes on the dorsal surface forming part of a fairly ornate pattern, anus small and scarcely visible, each jaw is armed with a single row of numerous sharp teeth capable of piercing human skin.

 Economic Value

Raised commercially in ponds in the 18th and 19th centuries especially in France, Hungary and Russia, they were used occasionally as economic barometers but primarily for blood-letting (phlebotomy), to drain haematomas and to enhance the success of tissue transplants. Blood-letting was a common medical practice and an estimated 25 million leeches were used in France in 1846 and a further 7 million in London hospitals in 1863. This large trade in medicinal leeches meant the indigenous supply had to be supplemented by large importations. H. medicinalis is also a popular subject for laboratory studies of morphology, physiology and behaviour and is now in high demand for experimental biology (2000 are used in the US per year), plastic surgery, the provision of pharmaceutical products and neurobiology (thought to be a model organism for studies as they have exceptionally large nerve cells and supporting glial cells). The saliva of H. medicinalis contains hirudin, the most powerful anticoagulant known. Hirudin is an acidic polypeptide with a molecular weight of about 7000. The collection of hirudin led to the destruction of a large number of leeches but now as a result of cloning and expression of a recombinant gene for hirudin in yeast and bacteria, fewer animals are destroyed. Other important compounds in the saliva are histamine (causes vasodilation of blood vessels in host), hyaluronidase (breakdown of host tissues increases permeability) and bdellin & eglin (basis of anti-inflammatory response in host). 

 Threats

In the past, over-collection of H. medicinalis for blood-letting has been blamed for the rarity of these leeches but in fact these leeches were frequently discarded into the nearest ditch or pond after use and this practice may have helped the survival of the species. However, more recent collections of H. medicinalis for experimental biology, medical and pharmaceutical needs pose a more serious threat as these leeches are destroyed. Today there is still a large trade in medicinal leeches which are still exported from France, Italy, Portugal, Hungary, Romania, Yugoslavia, Turkey and Greece (where they are supposed to be legally protected). The change or loss of prime medicinal leech habitat has also helped to hasten their decline. The alteration of many natural shallow ponds to deeper fishponds more suitable for trout and the general loss of wetlands, especially flushes and marshes, have not only reduced leech habitat but has also led to a decline in amphibians, an important host for the medicinal leech. Change in habitat, as well as their destruction, must be considered in conservation management for both the leech and their potential host species. The rearing of captive leeches is encouraged in order to reduce the number of individuals removed from the wild and the establishment of a leech farm in Swansea in 1984 was a welcome development. Its aim was to meet the world demand for leeches for use in research and medicine and today it provides the international market with around 15,000 leeches per year.

 Legal Protections

Although H. medicinalis has been removed from the UK BAP list as it is not considered to meet the UK priority species criteria, it is included in the 1996 International Union for the Conservation of Nature (IUCN) invertebrate red data book as a low risk, near threatened species, and also in the Finnish red data book. It was also added in March 1988 to the list of species protected under the Wildlife and Countryside Act (1981) making it an offence to kill, injure, take, posses or sell (alive or dead) H. medicinalis from the wild or to damage, destroy or obstruct access to their natural habitat.

Treat chest pain with leech therapy

 This type of pain is typically located around the heart and may vary in length and intensity: pricking, aching, piercing, sharp, momentary, lasting hours and even days (as though there is a stone lying on your heart). The pain is usually felt in the left part of the chest and may stretch as far as the left hand and back. Chest pains are often accompanied by various symptoms including: a strong connection with pain of the spine around the neck and chest level, diseases of the common bile duct, and hormonal imbalance. Oftentimes, physical activity has no effect on the pain, and neither does consumption of nitrates or other medications commonly used to prevent and relieve chest pain.

 

 Attachment Zones:

 

 Zone 1

 

 Top of the spine area

 

 Points 1, 2, 3

 

 Points 2 and 3 are 2 to 4 centimeters away from the center Point 1, which is located underneath C7, the bottom cervical vertebrae.

 

 Zone 2

 

 Area of the shoulders

 

 Points 4, 5, 6, 7

 

 Points 4, 5, 6, and 7 are located in the middle of the left and right shoulders

 

 Zone 3

 

 Area of the heart

 

 Points 16, 17, 18, 19, 20

 

 Point 16 is underneath the third rib near the sternum.

 

 Points 17 and 18 are 1 to 2 inch intervals from Point 16.

 

 Point 19 is on the edge of the chest right below the fifth rib and Point 20 is on the middle bottom edge of the chest.

 

 Zone 4

 

 Area between the shoulder blades

 

 Points 8, 9, 10, 11

 

 Point 11 is on T5-6, the fifth or sixth thoracic vertebrae. Points 9 and 10 are 1 to 2 inches to the right and left. Point 8 is on the level of T4-5.

 

 Zone 5

 

 Area of the lower back

 

 Points 11, 12, 13, 14, 15

 

 Point 15 is located at L2-3, second or third lumbar vertebrae. Points 11, 12, 13, and 14 are spaced from the center point at 1 to 2 inches intervals.

 

 Zone 6

 

 Area of the pelvis

 

 Points 21-27

 

 Points 21, 22, 23, 24, 25, 26, and 27 are spread in a semi circle on the lower abdomen starting at the center over the pubis (pubic bone).

 

Procedure Overview:

 

 When there is nerve pain and pain in the spine, use Zones 1, 2, 3 and 4. In the case of hormonal imbalance, use Zones 3, 4, 5, and 6.

 

 Quantity of attachments:

 

 Use 3 to 4 per session. When including Zones 3 and 4, use 4 to 8 leeches per course.

 

 Quantity of sessions:

 

 First 3 to 4 sessions should be conducted every other day using different zones, followed by additional 4 sessions 2 times a week. To solidify the effects of the entire course, follow-up with 2 to 3 sessions with a longer wait time in between. For aches and pains that have continued for a long time, make sure to include 2 to 3 sessions concentrating on Zone 3.

 

 Combination healing:

 

 While leech therapy can be the main treatment, for additional healing benefits, drink infusions and teas, such as hawthorn, intended for cardiovascular health.

 

 

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 Disclaimer: The purpose of this work is to provide as accurate information as possible regarding the subject of leech therapy. The actions and ideas put forth in this book are not intended to replace a consultation with a physician or other medical specialists. The author and/or publisher are not engaged in any professional medical services and are not liable for any injury, loss, or other damages purportedly caused by the use of the information found in this book. Do not attempt to apply any technique described in this book on your own, without first receiving proper training under the supervision of an expert.

Hirudotherapy

 

Hirudotherapy is a treatment with using of medicinal leech. This kind of therapy is known from the time of extreme antiquity and is still alive nowadays. This fact testifies to its efficiency at the decision of various problems of health. The method of hirudotherapy is approved by many countries. 

 

Enormous experience of using of medicinal leeches in the medical purpose is saved up during many centuries. With the development of science the mechanism of action of a secret of salivary glands of leeches was deciphered, biologically active substances which are included in it were opened,their influence on the certain structures of an alive organism is investigated. Some medical forms are created on a basis of biologically active substances of salivary glands of leeches and work on creation of new ones is conducting. Modern hirudotherapy differs from that of an ancient one because now we use not wild leeches but grown at a special biofactories where they are in severe quarantine. Besides, nowadays we use a leech only once. This fact completely excludes infection of a patient.

Therapeutic properties of hirudotherapy:

general reflexogenic

hypotensive

bloodletting

immunopotentiating

internal decongestion

bacteriostatic

anticoagulant

anti-inflammatory

protective antithrombotic

local anti-edematous

thrombolytic

analgesic

removal of microcirculation disorders

antiatherosclerotic

anti-ischemic

removal of abnormal intersystem interactions

 

 

 

 

 

Apothecary jar for Leeches which have been used for clinical bloodletting for thousands of years. The use of leeches in medicine dates as far back as 2,500 years ago, when they were used for bloodletting in ancient India. Leech therapy is explained in ancient Ayurvedic texts. Many ancient civilizations practiced bloodletting, including Indian and Greek civilizations.