Hirudo Therapy and Science II
Editor's Note: The video of leeches used in surgery is a bit bloody — especially after the 2-minute mark.
Leeches get a bad rap — but they might not deserve it.
Yes, they're creepy crawly blood-suckers. And they can instill an almost primal sense of disgust and revulsion. Humphrey Bogart's character in the 1951 film The African Queen even went so far as to call them "filthy little devils."
But the humble leech is making a comeback. This critter is increasingly playing a key role as a sidekick for scientists and doctors, simply by being its bloodthirsty self.
Distant cousins of the earthworm, most leech species are parasites that feed on the blood of animals and humans alike. They are often found in freshwater and navigate either by swimming or inching themselves along, using two suckers — one at each end of their body — to anchor themselves. Most species range from about a quarter inch to three inches in length.
Upon reaching an unsuspecting host, a leech will surreptitiously attach itself and begin to feed. It uses a triangular set of three teeth to cut in, and secretes a suite of chemicals to thin the blood and numb the skin so its presence goes undetected.
Some leech species can also live on land, thriving in humid environments like the forests of southern Asia. Biologists recently reported that leeches in that region can provide a valuable snapshot of which animals are present in a particular area: The parasites carry their host's blood, and DNA, within their gut after each meal.
"They find things you don't find," said Michael Tessler, a postdoctoral scholar at the American Museum of Natural History in New York. As an added bonus (depending on your perspective), leeches are also attracted to humans as potential blood meals, he said. Thus, the creatures do not shy away from researchers, making sample collection quick and easy.
Tessler and several colleagues gathered 750 terrestrial leeches in the genus Haemadipsa from Cambodia, Bangladesh and southern China. Then, they analyzed the DNA from each inch-long leech's meal to identify the unwitting blood donors. With this analysis, the scientists were able to identify wild and domestic animals common in those areas, including some species of concern for conservation.
The study also revealed a few surprises. Some leech meals had come from a few bird species, and one came from a bat. "Clearly these things get around," Tessler said.
Beyond their utility in field biology, leeches have an important role to play in a surgeon's medical kit.
The association between doctors and leeches dates back to the ancient Egyptians and ancient Greeks. According to Greek philosophers, illness was the result of an imbalance in bodily fluids, or humors. They believed that applying leeches to patients would help restore a proper balance. Leeches were widely used as a cure-all for an array of ailments, especially in medieval Europe.
These practices were relegated to the status of quackery by the advent of modern medicine in the 20th century as doctors developed new, more effective treatments. Nowadays, however, medical leeches are experiencing a renaissance as their bloodsucking ability is tuned to a more scientific purpose.
Leeches come in handy during reconstructive surgeries, such as those to reattach fingers, according to Dr. Rudolf Buntic, a hand surgeon and director of microsurgery for California Pacific Medical Center in San Francisco. During such a procedure, surgeons repair small arteries that carry blood into the severed digit. However, the tiny veins that carry blood back out may be too damaged or too small to repair, leaving blood to stagnate in the finger.
That's when Hirudo medicinalis comes in.
"The leech acts as a vein," said Buntic.
It draws stale blood out of the reattached finger as it feeds, allowing fresh, oxygenated blood to come in. Chemicals in the leech's saliva also help prevent blood clots from forming in the damaged tissue. Doctors apply fresh leeches over the course of about ten days. This provides enough time for new, tiny veins to regrow and create channels for blood to leave the patient's finger on its own, Buntic said.
Throughout the treatment, surgeons order leeches from the pharmacy, just as they would any other medicine.
If these little guys still give you the heebie-jeebies, don't worry: They probably won't be showing up at your local drugstore anytime soon, as they're primarily used in hospitals.
You might run into them in some research labs, however. David Weisblat, a biologist at the University of California, Berkeley, has been studying leech development and evolution for more than 40 years. He's recently started a project to learn more about leech behavior and neurobiology.
This involves placing the leeches onto a checkerboard of sorts, made of sandpaper. The squares alternate between rough and smooth grains. Many of the leeches, small snail-hunters in the genus Helobdella, have a strong preference for the smoother squares, moving in strictly diagonal patterns.
"It's like a little pawn on the chessboard that's gone crazy," Weisblat said.
Though leeches may have an unimpressive nervous system by vertebrate standards, they are still capable of using information from their environment to make decisions, said Weisblat. And figuring out how this process works is easier in a leech than in the nervous system of mice or rats. In understanding how leeches find their way around with so few neurons, we can begin to understand how the nervous system processes and encodes information, Weisblat said.
Capturing the way leeches sense and move through their environment could also one day translate to bioengineering applications, like designing small, exploratory robotics, said Weisblat. "Leeches can go on glass surfaces, crawling with their suckers, and exploring all sorts of different ways," he said.
"It's pretty amazing, when you think about how simple they are."
Emma Hiolski is a freelance science journalist and intern with KQED's Deep Look video series. Her work has appeared in Science, Chemical & Engineering News and The San Jose Mercury News. You can find her on Twitter @EHiolski.
Leech therapy: help with osteoarthritis, back pain and high blood pressure
Leech therapy - sounds disgusting, but can work wonders - especially in pain. The use of small bloodsuckers is now medically recognized for chronic pain in the lower back and for osteoarthritis. The leech saliva contains many health-promoting substances, which in combination can alleviate various diseases. Not only naturopaths swear by this age-old naturopathic treatment, but also more and more conventional medicine.
What is leech therapy?
In leech therapy, several medicinal leeches are placed on the skin of a person for healing purposes, where they have pain or other health problems. The leeches now follow their natural instinct: they suck themselves tight and begin their meal by drawing blood from their host, i.e. human beings. This is not much per therapy session - only about 10 milliliters per leech. With bleeding, it is between 35 and 50 milliliters.
Leech treatment is comparable to bloodletting - a traditional healing method that has been used in folk medicine for several thousand years. On the one hand, harmful substances are eliminated with the loss of blood, on the other hand, the saliva of the leech has extensive healing powers that can help with numerous complaints such as back pain or knee joint pain.
What are leeches?
Leeches belong to the ringworms just like the earthworm. The term "leech" is derived from the Greek word "echis", which stands for "little snake". The leech can reach a size of up to 15 centimeters and an age of 30 years. There are over 600 leech species in the world. For medical purposes, however, only the medical leech (Hirudo medicinalis) is suitable, which occurs in Europe as well as in North Africa and Asia Minor. It has a brownish color, black spots on the belly and red stripes on the back.
In the wild, where they live in fresh water such as streams or pools, the leeches feed on animal blood, especially that of cattle. You enter into a symbiosis with the animal. The leech gets the blood, the host the health-promoting substances of its saliva. The leeches can absorb 5 to 10 times their body weight in blood. This provides the annelids with food for two years. The leeches with their three jaws and the very fine teeth between which the saliva is secreted and transferred to the host generate the enormous suction. Due to the great popularity of leech therapy at the beginning of the 19th century, useful bloodsuckers became rare in nature, which is why they are protected in many countries.
Where do the medical leeches come from?
Since the medical leeches can hardly be found in nature, pharmacies, medical practices or naturopaths order them from special breeding facilities. You can import the ringworms from other countries such as Bulgaria or Turkey.
Origin of leech therapy and rediscovery of the gentle healing process
Leech treatment or hirudo therapy is a healing method that was already known in Mesopotamia, i.e. around 3000 years ago. The medical scholars of ancient Egypt or India around 500 BC have already practiced this form of bloodletting. In the Middle Ages, this natural therapy with few side effects was also used in Europe. Today, the healing effects of leech therapy are valued again, which is why it is used again in alternative medicine as well as in conventional medicine.
Which ingredients are responsible for the healing effects in leech therapy?
Leech therapy can score with various healing effects. The leech's saliva contains over 100 active substances, 20 of which have proven healing properties. The special healing effect of leech therapy comes about due to the combination of these medicinally active ingredients. In addition to hirudin, calin, eglin, bdellin, as well as destabilase and apyrase, various active substances are factor Xa inhibitors and hyaluronidase.
Effect of leech therapy
By having the leeches such on specially selected skin areas of humans, leech therapy has the following effects:
- • Pain relief
- • Promotion of detoxification and purification (and thus support the healing process)
- • local loosening of the tissue (e.g. muscle tension)
- • relaxing effect
- • anti-inflammatory effect
- • antibiotic effect
- • Blood thinning effect and improved blood circulation
- • Inhibit blood clotting
- • Releases congestion in veins, lymphatic vessels and other tissues
- • Prevent blood clots from forming or dissolve existing clots
For which diseases is leech therapy used?
Leech therapy is not used to cure diseases such as osteoarthritis or rheumatoid arthritis. Rather, it is about alleviating the associated complaints - especially the severe pain. Therefore, the main area of application for leech treatment is pain therapy and, above all, the treatment of chronic pain.
Leech therapy for osteoarthritis
With osteoarthritis (joint wear), such as knee osteoarthritis, which is accompanied by severe knee pain, leech therapy has been shown to show positive treatment success. According to a study by the University of Duisburg-Essen, leech therapy is effective for knee osteoarthritis, wear of the knee joint. Many patients were able to use the “living medicines” to help them to be free of pain, to have more flexible joints, or at least to reduce joint pain. Based on the positive results of this study, conventional medicine recommends leech therapy for osteoarthritis in various joints (such as the elbow, ankle, hip, sacroiliac joint or thumb saddle joint).
Leech therapy for rheumatoid arthritis, rheumatism and gout
In rheumatism, leech treatment is also a recognized medical therapy to relieve pain. The comprehensive effects of leech therapy are based on the fact that various healing effects come together. Chronic pain, such as rheumatism, rheumatoid arthritis or gout, is always accompanied by tissue congestion. For example, muscles are tense, the lymph fluid or the blood cannot flow properly at the painful area. Stored cell toxins often play a role in the pain process.
If blood is drained from the painful joint or back pain on the back with the leeches, the harmful substances are excreted in the area, which is enough for some diseases to initiate the healing process. If tense muscles or glued fascia (connective tissue) also dissolve due to improved blood circulation and more blood or lymphatic fluid flow at this point than before, these changes have a positive effect on the pain condition.
Inflammation plays a major role in many chronic diseases - including rheumatism, arthritis or gout. These inflammations are contained by the anti-inflammatory agents in the leech saliva, which can reduce joint pain or back pain. Some experts believe that leech therapy is more effective, has fewer side effects and is therefore more recommendable than pain therapy with painkillers (e.g. non-steroidal anti-inflammatory drugs) - especially if the painkillers have to be taken permanently.
Leech treatment for chronic back pain
The efficacy of leech therapy could also be demonstrated for chronic low back pain, one of the most common spinal disorders. Here, the little bloodsuckers can significantly alleviate the pain in the lumbar spine through their decongestant, anticonvulsant and circulation-promoting effects - and for a long time. In addition, the active substances in leech saliva can improve the mobility of the lumbar spine in those affected and reduce their pain medication consumption.
Last but not least, leech therapy can help many people overcome their depression or depressive mood, which is often associated with chronic pain, and thus improve their quality of life. Treatment with leeches for back pain or complaints in the cervical or thoracic spine can also be successful.
Leech therapy for fibromyalgia
In naturopathy, leech therapy is also used for fibromyalgia. This disease, which is very widespread today, causes chronic muscle pain in several parts of the body such as the back, shoulders and legs. This chronic pain in the muscles can be reduced by decongesting the surrounding tissues such as the lymph or blood vessels, by removing harmful cell toxins, by improving blood circulation, for example by loosening the muscles.
Leech treatment for fibromyalgia is an alternative and effective naturopathic treatment that is preferable to the continued use of painkillers. Typical complaints of fibromyalgia such as shoulder pain, arm pain and leg pain as well as exhaustion and sleep disorders can be effectively reduced with this living natural remedy.
Leech therapy for varicose veins, thrombosis, phlebitis and spider veins
Another area of application for leech therapy is venous disease. In varicose veins (venous insufficiency), the contents of the leech saliva improve the flow properties of the blood, so that the congestion in the veins decreases and the varicose veins can go back. This also reduces the associated pain in the legs and swelling. Some studies have confirmed the healing effects of leech treatment on varicose and spider veins (tiny varicose veins). For ulcers (open legs) that develop due to venous insufficiency, the alternative healing method can cause them to heal faster.
Natural medicine takes advantage of the anti-inflammatory properties of leech saliva in the case of phlebitis, i.e. inflammation of the vein wall. These often go hand in hand with varicose veins. The active substances in leech saliva can effectively help to reduce the inflammation in the veins and improve the symptoms.
Blood clots (thrombosis) can also result from phlebitis. Leech therapy can have positive effects both in the prevention of thrombosis and in the treatment of existing thrombosis. Because the gentle naturopathic treatment helps to thin the blood and dissolve blood clots.
Leech therapy for high blood pressure
In studies, people with high blood pressure were able to lower their blood pressure by 20 points using leech therapy. As a result, many needed less medication to regulate high blood pressure. So the natural healing method is a good alternative to chemical hypotensive. If the leech treatment is repeated every 2 to 3 months, the reduced blood pressure can even remain at this level permanently, according to a study.
The researchers explain the effect of leech therapy in that new red blood cells form, which are more flexible and have to be pumped through the blood vessels with less pressure. The scientists see a second explanation for the fact that the amount of iron in the blood drops through the mini-bloodletting, which means that the inner lining of the blood vessels - as if the amount of iron is too high - would no longer be damaged and the vessels would no longer cramp. This could make blood transport work better. Many people with high blood pressure have an excess of iron in their bodies that damages the blood vessels.
Leech therapy for migraines
Researchers do not yet agree why leech therapy can help with migraines. It is believed that mini-inflammation plays a role in the unbearable headache as well as reduced blood flow to certain areas. Because the ingredients of the leech saliva contain inflammation and promote blood circulation, it is possible that the leech treatment for migraine complaints such as visual disturbances, headaches or nausea works for these reasons.
Leech therapy for tinnitus
In our stressful time, many people suffer from tinnitus - the excruciating ringing in the ears, which the body often answers in response to a psychological overload. Because even the smallest vessels, which supply the ear with oxygen and nutrients, contract under tension. This can lead to circulatory disorders in the inner ear, which can be accompanied by ringing, noise, whistling or humming. Blood leech therapy improves blood flow to the ear, the nutrients get to the ear better, and the vessels expand and relax. While leeches cannot cure tinnitus, at least experience medicine shows that the symptoms improve in many people, so that the quality of life of those affected increases again.
Leech therapy for endometriosis and resulting infertility
Leech therapy can also help women with endometriosis. With this disease, women suffer from severe menstrual pain, pelvic pain and often infertility. Tissue that actually belongs in the uterus grows here outside the organ - in the abdomen. The fallopian tubes and ovaries often stick together, which prevents pregnancy from occurring. The anti-inflammatory and pain relieving active ingredients in leech saliva can reduce the pain in affected women. Decongesting the tissue in the female genital organs with improved blood flow can ultimately lead to the symptoms of endometriosis diminishing and the desire to have children still being fulfilled.
Leech therapy for hemorrhoids
Even if many people don't dare: leech therapy can even be used for hemorrhoids. Some hemorrhoid ointments contain the corresponding active substances of the leeches. The healing bloodsuckers can also be used directly. There are already many experience reports from naturopathic practices, in which those affected could achieve good healing successes with hemorrhoids with the leeches. Leech treatment is a side effect-free way to effectively relieve hemorrhoid symptoms such as burning, itching or pain in the anus.
Other uses of leech therapy
In addition, naturopaths, naturopaths, and in some cases also school medicines, use leeches for the following diseases:
- Chronic inflammation of the sinuses (inflammation of the sinuses) and otitis media
- Testicular inflammation
- Inflammation of the gallbladder
- Inflammation of the breast
- muscle tension
- tennis elbow
- congestion in the lymphatic vessels (lymphedema)
- shingles (herpes zoster)
- Infections from insect bites
How does leech therapy feel? Is the treatment painful?
Leech therapy is little to not painful. Firmly sucking the leeches is often compared to the feeling of a pinprick. Many people describe what follows as if they had touched a nettle.
Procedure of leech therapy
Preparation of leech therapy
First of all, you should inquire with the doctor whether leech therapy is suitable for you and your symptoms. If you are taking medication, ask the doctor if it can interact with leech therapy. Find a specialized therapist. Since the leeches are sensitive to smell, you should not apply soap, shower gel or cream to the affected area 3 days before the treatment.
On the day of leech therapy, you should rest and drink plenty of water. Choose comfortable clothes and choose a comfortable sitting position before starting that you can take for about 2 hours. The therapist rubs the skin with a damp cloth to optimize blood circulation there. The place where the leech should suck is marked or slightly scratched.
Implementation of leech treatment
Now the therapist places several leeches on the appropriate spots. They immediately suck themselves up. During treatment, the animals release their healing saliva into the wound. After 40 to 90 minutes they have reached their maximum intake volume and fall off on their own. The leeches must not be torn off prematurely because parts of the jaw can get stuck in the wound or the leech vomits, so that undesirable substances get into the wound. If the treatment has to be interrupted - for whatever reason - the experienced therapist will try with a wooden spatula to carefully detach the jaw of the gel from the skin.
Follow-up treatment and treatment tips
The wound continues to bleed for up to 24 hours after the leeches are released because the animals have inhibited blood clotting. This effect is desirable and therefore does not constitute a side effect. A bandage is placed on the area, which is changed by the therapist every hour after heavy bleeding, later after 12 hours.
Procedure afterwards: While you have the bandage and the wound is not yet closed, you should not take a shower. On the day of leech therapy and the day after, please do not exercise or perform other strenuous movements. If the wound is itchy, do not try to scratch it, otherwise it may catch fire.
The leeches may only be used once, otherwise there is a risk of causing infectious diseases in another person. Following treatment, the leeches are either killed professionally - by freezing or 100% alcohol - or returned to the breeding company.
Duration of leech therapy
Leech therapy with preparation and aftercare can take up to 4 hours. Sucking the leeches themselves takes 40 minutes to 90 minutes. Because of the bleeding, the aftercare must be done carefully, which takes a certain time.
How often should leech therapy be done?
How quickly leech therapy works varies. The desired effect is often achieved after just one application. In these cases, pain relief occurs immediately after leech treatment. In other people, such as those with knee osteoarthritis, the leech treatment is often repeated before the knee pain subsides or at least improves. As a rule, 3 treatments for chronic pain such as back pain or joint pain for rheumatism are considered sufficient. Very rarely, repeated use of leech therapy over a long period of time is required.
How long does the effect of leech therapy last?
How long the effect of leech therapy lasts also varies from person to person. Some people are symptom-free for a few days, so they no longer have pain or restricted movement, while others can spend several weeks, half a year or several years without symptoms such as pain in the joints or back pain.
Who can carry out leech therapy?
You can have leech therapy with medicinal leeches in a naturopathic practice as well as in specialized medical practices or clinics (outpatient or inpatient). At these addresses you can be sure that the leeches come from breeding and are not contaminated with viruses or bacteria.
Cost of leech therapy
The costs of a leech therapy are not covered by the health insurance, unless you have additional insurance for naturopathic procedures. However, if you have the treatment carried out in a hospital, the costs will be borne. The price for a leech treatment at a naturopath is around 300 euros, including consultation, treatment and aftercare. You have to bear these costs yourself.
What side effects or risks can occur with leech therapy?
Leech therapy is generally considered a gentle, natural therapy with few side effects. There are hardly any side effects to be expected. However, like any medical therapy, certain side effects cannot always be excluded with leech therapy. These include reddening of the skin, swelling, infections, bruising, itching, pigmentation disorders or allergic reactions, but these are not a danger. In individual cases, leech therapy can lead to increased bleeding, circulatory problems with a drop in blood pressure, fever and chills. In these cases, you should see a doctor.
When should leech therapy not be performed? – contraindications?
Leech therapy is not recommended for everyone. The naturopathic treatment should not be used for:
- • pronounced weakness of the immune system
- • advanced cancer or other serious chronic illness
- • during chemotherapy
- • after an organ transplant
- • dialysis patients
- • severe allergies (e.g. to the saliva of the leech)
- • anemia
- • Blood clotting disorders and when taking blood thinners
- • advanced peripheral vascular disease
- • advanced liver disease such as cirrhosis
- • acute stomach or intestinal ulcers
- • poorly controlled diabetes mellitus
- •during pregnancy
- • Autoimmune diseases
- • Diseases in the arterial vascular system
- • children
Leech therapy on animals: treat dogs, horses or cats with leeches
On animals such as dogs, cats or horses, leech therapy can also be used and help relieve symptoms such as joint pain or stiffness in the joints. To have leech therapy performed on your animal, you should see a specialized and experienced therapist. In the case of dogs, cats or horses, these are veterinarians or veterinary practitioners. The leeches are then already available for on-site treatment. You should not use it yourself on horses or dogs, because you have to know which areas of the skin the leeches have to be attached to in order to relieve suffering. The cost of leech treatment for horses or dogs is between 200 and 300 euros.
Treatment of gonarthrosis with Hirudo Medicinalis (medical leech): How does the therapy affect the sensation of pain and the mechanical touch threshold?
Gonarthrosis is one of the most common chronic diseases in the western world. The prevalence is over 10% among those over 55; a quarter of these are severely affected (Peat et al. 2001). The recommended therapy for gonarthrosis consists of a combination of non-pharmacological and pharmacological therapy options (Jordan et al. 2003). The group of NSAIDs (non-steroidal anti-inflammatory drugs) is used most frequently. However, side effects can occur especially in long-term therapy (Seed et al. 2009). It therefore makes sense to look for new treatment options.
These include treatment with Hirudo Medicinalis (medical leech), the effectiveness of which has been demonstrated in several studies using validated pain and function questionnaires (Michalsen et al. 2001; Michalsen et al. 2003; Andereya et al. 2008).
On the other hand, the specific mechanisms by which the effectiveness of leech treatment is mediated are unclear. In this study, it was therefore specifically investigated how the treatment of knee osteoarthritis with leeches affects the pain, vibration and touch sensation on the affected joint.
Methods / study design
The study was carried out as an application observation, in which only the routine work in the study center was documented. Since this was a pilot project in which the first data on the topic was to be generated, there was no division into therapy and control groups and therefore no randomization. The aim of the study was first to describe phenomena that arise from leech therapy and were measured with the instruments described below.
The study center was the Rheumatism Center Middle Hesse in Bad Endbach. This clinic has many years of experience in the treatment of rheumatological and orthopedic diseases.
42 patients with clinically and radiologically proven gonarthrosis participated in the study. Patients of both sexes were included
▶ between the ages of 40 and 85
▶ with a body mass index <35 kg / m2
▶ with bilateral gonarthrosis according to the criteria of the American Society of Rheumatology (Altman et al. 1986)
▶ with an X-ray arthrosis stage II – III according to Kellgren and Lawrence
▶ with an indication for leech therapy in accordance with the treating doctor
▶ with knee pain on most days of the past three months
Patients with secondary forms of osteoarthritis, severe comorbidity, systemic corticoid medication, existing anticoagulation or hemophilia have been excluded.
Main target criteria
The main goal criteria were changes in the Pressure Pain Threshold (PPT), the Mechanical Touch Threshold (MDT) and the Vibration Detection Threshold (VDT). These methods are subtests taken from the QST (Quantitative Sensory Testing) battery of the German Research Network for Neuropathic Pain (DFNS) (Rolke et al. 2006a, 2006b).
Pressure pain threshold PPT
The pressure pain threshold was measured with an algometer (Somedic AB, Hörby, Sweden). The metal stamp of the algometer has a contact area of 1 cm² and was placed on the skin at a right angle with constantly increasing pressure. Initially, the test subjects registered the touch and, in the coming course, increasing pressure. As soon as this pressure was felt to be painful, the test persons actuated a button attached to the measuring device, whereupon the measurement was stopped. This test was carried out at five different locations on both knees and on the palms of the hands.
Mechanical contact threshold MDT
The MDT was measured with so-called fiberglass hairs of different diameters, calibrated by Frey Härchen (Somedic AB, Hörby, Sweden), which are attached to a plastic handle. They have been specially developed to exert a defined pressure on the skin area in order to determine the intensity at which a touch on the surface of the skin was perceived. This measurement was carried out at two different locations on both knees and on the hands.
Threshold of vibration sensation VDT
The VDT was determined using a conventional Rydel-Seiffer tuning fork as used in neurology. Scaled weights are attached to the two jaws of the tuning fork, which are set in motion by the vibration of the tuning fork. The normal value is 8. If the sensation of vibration is reduced, it is lower. This tuning fork was vibratingly placed on the bones of the wrists (processus styloideus ulnae) and on the kneecaps. Normally, the subjects perceived the vibration for a certain period of time. As soon as they no longer felt vibrations, they were obliged to tell the examiner.
The WOMAC (Western Ontario and McMaster Universities Arthritis Index) is a specific questionnaire to be filled in by the patient with 24 questions, which determines the patient's state of health in the three directions of pain, joint stiffness and movement restrictions (function) and has been adapted for the German-speaking area ( Stucki et al. 1996; Bellamy et al. 1988).
Each question should be answered by the patient using a numerical analog scale from 0 to 10 (none - extreme). In order to be able to assess the pain on both knees separately, the patients were presented with two 10 cm long visual analog scales (VAS). The patients were instructed to place a cross at the point on the line that represented the pain at the respective knee (0cm - no pain, 10cm - most pain imaginable).
The frequency and amount of pain medication, as well as any medication that may be required, were taken from the study center patient files.
In addition, it was to be determined whether - due to the gonarthrosis - there was a distorted perception of the patient's knee pattern and a change after the leech therapy could be determined. For this purpose, each patient was asked to select one of eight different standard drawings of the right or left extremity, which most closely reflects their subjective size perception of the knee. The circumference of the knees was then measured using a tape measure.
Course of study
After checking the inclusion and exclusion criteria and the information provided by the doctors at the study center, the potential study participants were given test information and a declaration of consent in writing (Day -3).
On day 0, the study participants had to answer the questionnaires (WOMAC, VAS, knee diagram). The measurements were then carried out using the instruments described above. Finally, the knee diagram was presented to the patient and explained, and the circumference of the knees was measured. The leeches were then treated on the more affected knee. On day 7 after the treatment, the test subjects appeared for the second measurement and questioning. They were again given the questionnaires mentioned above and then the corresponding measurements were carried out.
The leech treatment was carried out in the rooms of the Rheumatism Center in Central Hesse. It was carried out in the form of a single local application of 3-5 leeches (Hirudo medicinalis) on the knee of the more painful side.
The leeches were placed in the area of the affected painful joint. The treatment was done while sitting or lying down. The relevant places had been marked by a doctor in consultation with the patient.
The leeches were removed from the leech container manually by trained personnel (using tweezers) and attached, gloves were always worn. The spontaneous drop of the gel was always waited for, this took an average of 20 to 60 minutes. The fallen leeches were disposed of by the staff in a designated container. First the bite wounds were covered with sterile swabs. In connection
an association was created on it. The next morning, the patients introduced themselves to check the wound and to change the dressing.
All evaluations were based on the intention-to-treat principle, i.e. H. Patients who were included in the study were included in the evaluation, regardless of whether they were treated according to the protocol or not and whether they provided data at all times of the survey or not.
Sensitivity analyzes also included evaluations based on the per-protocol population, i.e. H. of all patients who received a single leech therapy and had completed the main examination after 6–8 days.
Changes in the main and secondary target criteria were analyzed using multiple regression models in which expectations and gender were classified as factors and age as well as the respective baseline value entered the model as linear covariates.
A total of 42 patients aged 70.4 ± 9.8 years were enrolled in the study. The oldest participant was 84 years old, the youngest 49 years. Two thirds of the patients were female. A third of the patients were treated on an outpatient basis, the others inpatient treatment. Two thirds of the subjects received additional treatments during the observation period. Physiotherapy (59.5%) and treatment with clay (28.6%) predominated here. Furthermore, two thirds of the subjects took pain medication during the course of the study. Side effects occurred in five patients (11.9%). There was excessive itching, severe reddening and swelling of the treated areas, but at the latest one week after the treatment, the symptoms improved considerably.
As expected, the touch threshold in the control area, the hands, did not change. Above the kneecap and above the pain maximum, however, there was a decrease in the contact threshold, which was significantly stronger on the more painful knee than on the less painful one. Above the pain maximum, this decrease reached the level of significance.
With regard to the pain threshold, a reduction was found in almost all test areas, although the level of significance was never reached with one exception (on the hand of the less affected side). The vibration sensation threshold increased significantly on both wrists and on the kneecap on the less affected side. In contrast, there was no change in the knee on the more affected side.
Pain and function
After leech therapy, there was a significant improvement in two of the three WOMAC indices (pain and daily activity) and the global index, and a non-significant improvement in stiffness. In the more painful knee, there was a significant reduction in pain measured by VAS from 5.4 to 3.0. In contrast, no change was found on the less painful knee. Taking the drugs ASA (acetysalicylic acid) and ibuprofen showed no change in the comparison of the values before and after the therapy. In contrast, the drugs Diclofenac and Novalgin were taken more frequently.
Knee circumference and knee diagram
The treated knee was perceived as thicker than the untreated knee in the side comparison before and after therapy, so the subjective extent of the more painful knee before therapy was 1.4 (± 1.6) points, that of the less painful knee was 1 , 0 (± 1.5) points. After treatment with leeches, the perceived extent decreased slightly to 1.0 (± 1.6) or 0.5 (± 1.8) points. Both knees were therefore felt to be slightly thinner after the therapy. The actual size of the knee did not change.
This is the first study to collect detailed neurological data on the possible mechanisms of action of leech treatment for gonarthrosis. Although these are only pilot data, the results allow the conclusion that a single leech treatment in gonarthrosis patients can change the touch thresholds. The lack of a control group limits the meaningfulness of the results found, as well as the fact that the majority of the study participants have received accompanying treatments and the short observation period of only seven days.
A reliable clinical assessment of the effects found is also difficult because there are still no reference data for the measured values on the knee to check the validity of the data.
However, the small number of missing values and the good reliability of the measurement methods in themselves suggest that the methods chosen are suitable for validly recording changes in connection with leech therapy and thus contribute to an explanation of the effect of leech therapy.
The distinctive ability of leeches to influence blood clotting has long been known. The hirudin formed in the salivary glands of the egg is responsible for this. In this context, leeches have traditionally been used in thrombotic occlusion and stroke in many medical systems around the world. Since the hirudin can be synthesized pharmacologically, the outstanding anticoagulant effect of the hirudin has been proven in a large number of studies. Hirudin and related advancements are now firmly established in angiology and cardiology for anticoagulation.