Medicinal Leech Therapy E-Book

Gustav Dobos

• Herausgeber: Thieme
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 283

Veröffentlichungsjahr: 2007

Beschreibung

Medicinal leech therapy has undergone a renaissance in recent years, both in terms of how well the effects of using leeches are understood,and in the discovery of new clinical applications that have resulted in remarkable outcomes. This timely book introduces the basic principles of using leeches in clinical practice, and clearly sets out the methodology and potential applications. Emphasis is given to those areas of medicine where scientific studies have already provided firm evidence of success -- treatment of arthrosis and pain is already benefiting from this highly effective therapy. Excellent instructions for the use of leeches cover the full spectrum of possible applications, while the encouraging new developments in research are also addressed. This valuable guide for physicians to this important therapy comes from the acknowledged experts in the field.

Leseprobe

Library of Congress Cataloging-in-Publication Data.

Blutegeltherapie. English.

Medicinal leech therapy/[edited by]Andreas Michalsen, Manfred Roth, GustavDobos; with contributions by M. Aurich…[et al.]; [translator, Suzyon O'Neal Wandrey].

p.; cm.

“This book is an authorized and revised translation of the German edition published and copyrighted 2006 by Karl F. Haug Verlag, Stuttgart, Germany. Title of the German edition: Blutegeltherapie.” Includes bibliographical references and index.

ISBN-13: 978-3-13-143581-1 (GTV: alk. paper)

ISBN-10: 3-13-143581-X (GTV: alk. paper)

ISBN-13: 978-1-58890-563-5

(TNY: alk. paper)

ISBN-10: 1-58890-563-2 (TNY: alk. paper)

1. Leeches–Therapeutic use. I. Michalsen, Andreas. II. Roth, Manfred, PhD. III. Dobos, Gustav. IV. Aurich, M. (Michael) V. Title.

[DNLM: 1. Leeching.

WB 381 B659m 2007]

RM182.B5813 2007

615‘.321–dc22                                                                                                                       2006101407

Translator: Suzyon O'Neal Wandrey, Berlin, Germany

© 2007 Georg Thieme Verlag,Rüdigerstrasse 14, 70469 Stuttgart, Germanyhttp://www.thieme.deThieme New York, 333 Seventh Avenue,New York, NY 10001, USAhttp://www.thieme.com

Typesetting by OADF, HolzgerlingenPrinted in Germany by Appl, WemdingISBN: 978-3-13-143581-1 (TPS, Rest of World)ISBN: 978-1-58890-563-5 (TPN, The Americas)1 2 3 4 5 6

Important note: Medicine is an ever-changing science undergoing continual development. Research and clinical experience are continually expanding our knowledge, in particular our knowledge of proper treatment and drug therapy. Insofar as this book mentions any dosage or application, readers may rest assured that the authors, editors, and publishers have made every effort to ensure that such references are in accordance with the state of knowledge at the time of production of the book.

Nevertheless, this does not involve, imply, or express any guarantee or responsibility on the part of the publishers in respect to any dosage instructions and forms of applications stated in the book. Every user is requested to examine carefully the manufacturers’ leaflets accompanying each drug and to check, if necessary in consultation with a physician or specialist, whether the dosage schedules mentioned therein or the contraindications stated by the manufacturers differ from the statements made in the present book. Such examination is particularly important with drugs that are either rarely used or have been newly released on the market. Every dosage schedule or every form of application used is entirely at the user's own risk and responsibility. The authors and publishers request every user to report to the publishers any discrepancies or inaccuracies noticed. If errors in this work are found after publication, errata will be posted at www.thieme.com on the product description page.

Some of the product names, patents, and regis tered designs referred to in this book are in fact registered trademarks or proprietary names even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain.

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Preface

The medicinal leech is a beautiful symbol of give-and-take and of sustainable resource management. Hirudo medicinalis is one of the oldest surviving animals on Earth. The first documented accounts of the use of leeches for medicinal purposes date back to the time of Hippocrates. There are two decisive factors in the survival of the “leech” species: a) the blood that it extracts from the host does not coagulate, and b) the leech bite is not painful. Hirudin, the anticoagulant compound in leech saliva, was isolated several years ago. In this modern age, hirudin is manufactured as a genetically engineered product, the efficacy of which has been tried and tested in large-scale, randomized controlled trials in a number of indications.

The retrospective on the therapeutic use of analgesic substances in leech saliva is a completely different story; these developments are still in their infancy, and the first systematic trials using live leeches were only conducted a few years ago. One phenomenon that was repeatedly observed during treatment and research with live leeches is that the relationship between leeches and humans is special. While the media would hone in on the “yuck factor,” we constantly observed a great public interest in natural healing methods, especially leech therapy. Hundreds of people responded to our calls for volunteers for leech studies in Essen, Germany. In most cases, we had more than ten times more willing candidates than we actually needed for the study. Therefore, we often asked ourselves: Could the human mind possess something like a phylogenic memory for the positive effects of leeching? One could almost think that humans subconsciously know that leeching is good for them. The systematic studies of leeching performed in the last five years support this theory, and the interest of patients in leech therapy has grown accordingly. This trend started in Germany and spread to other parts of the world following the publication of our leeching study in the Annals of Internal Medicine“and, later, in The New Yorker. Thanks to these important articles on the medicinal leech and its therapeutic potentials, substantial interest in this ancient form of treatment has even spread to the USA.

After receiving numerous queries from Anglo-American countries, we ultimately decided to publish the present English edition of this book. By doing so, we would first like to offer scientific evidence to counteract the common misconceptions about leeches. Secondly, we would like to share our enthusiasm for the medicinal leech with others. Leeches are not disgusting creatures! They are classified as a medicinal product in Europe and as a medical device by the US Food and Drug Administration. Based on the scientific evidence, it no longer seems appropriate to classify the leech as a parasite—especially when one considers that humans have often pushed the leech to the verge of extinction because of its healing properties. As far as we are concerned, the leech is a “healing animal.”

Our special thanks go to the Karl and Veronica Carstens Foundation for their many years of support for medicinal leech research. We also would not want to miss this opportunity to thank their Director, Dr Henning Albrecht, who shared our visions of scientifically tested integrative medicine, as well as Rainer Lüdtke, biometrician, for his very competent advice regarding statistical questions.

On behalf of all the authors, we wish you interesting insights into leech therapy and many successful treatments.

Gustav Dobos, MD

Manfred Roth, PhD

Andreas Michalsen, MD

Contributors

Michael AurichZAUG GmbHBiebertal Leech FarmBiebertal, Germany

Marco Blessmann, MDOral and Maxillofacial SurgeryUniversity Hospital EppendorfHamburg, Germany

Petra FleckenOberursel, Germany

Joerg Graf, PhDDepartment of Molecular and CellBiologyUniversity of ConnecticutStorrs, CT, USA

Ulrich GrossBad Nauheim, Germany

R. Schmelzle, MDProfessorOral and Maxillofacial SurgeryUniversity Hospital EppendorfHamburg, Germany

Ulrich Storck, MDRheumatic Disease CenterMittelhessenBad Endbach, Germany

Ellen Wittke-MichalsenHealth Supplies StoreKnappschaftskrankenhausEssen, Germany

Contents

1 Introduction

A. Michalsen, M. Roth

2 The History of Leech Therapy

E. Wittke-Michalsen

Leeching in Ancient European Medicine

Leeching in the Middle and Modern Ages

Leech Therapy in Recent Times

3 The Biology of Leeches

M. Roth

Introduction

The Evolutionary History of Leeches

Anatomy and Function

Oral Anatomy and Function

Skin, Muscles, Nerves, and Senses

Leech Behavior, Habitat, and Care

Reproduction

Medicinal Leech-Keeping and Breeding at Our Breeding Center

Summary of Leech-Keeping Practice

4 The Technique of Leech Therapy

E. Wittke-Michalsen

Skin Preparation Measures

Leech Application Procedure

5 Indications for Leech Therapy

P. Flecken, A. Michalsen

Venous Disease; Varicose Veins

Arthrosis

Rheumatic Diseases

Tendovaginitis (Lateral Epicondylitis) and Tendinitis

Vertebrogenic Pain Syndromes

Further General Indications

6 Leech Therapy in Rheumatic Disease

U. Storck

Muscle Tension

Inflammatory Reactions in Connective Tissue and Connective Tissue Zones

7 Leech Therapy in Plastic Surgery

M. Blessmann, R. Schmelzle

Theory

Case Studies

8 Contraindications

P. Flecken, A. Michalsen

Hemophilia, Anticoagulant Medications

Anemia

Erosive Gastritis and Potential Gastrointestinal Bleeding

Acute Stages of Infectious Disease

Serious Organic Disease and Immunosuppression

Severe Allergic Diathesis

Pregnancy

General and Local Wound-Healing Disorders

Keloids

Lack of Patient Consent

9 Safety and Adverse Effects of Leech Therapy

A. Michalsen

Local Pain During Treatment

Local Itching

Hypotension and Vasovagal Attacks

Blood Loss

Impaired Wound Healing, Superinfection, and Allergies

Sepsis

Transmission of Infectious Diseases

Scarring

10 The Scientific Basis of Leech Therapy

A. Michalsen

Mechanisms of Leeching and Their Clinical Correlatives

Proof of Efficacy in Specific Clinical Indications

Special Features of Clinical Research with Leeches

11 The Biochemistry of Leech Saliva

U. Gross, M. Roth

Components of the Saliva of the Medicinal Leech

Components of the Saliva of Other Leeches

Recombinant Anticoagulants

12 Bacterial Flora of the Medicinal Leech (Hirudo medicinalis)

J. Graf

Intestinal Symbiosis of the Medicinal Leech

Aeromonas, Intestinal Symbiont of the Medicinal Leech

Microbiology of the Leech

Antimicrobial Properties of the Leech Intestine

13 Medicinal Leeches in Integrative Medicine

G. Dobos

Why Integrative Medicine?

Integrative Medicine in Germany

Example: Leech Therapy for Osteoarthritis of the Knee

Respecting the Wishes of the Patient

How Does Leeching Fit into CAM?

14 Legal Aspects of Leech Therapy in the EU and USA

M. Aurich

What is the Legal Status of Leech Therapy?

What Qualifications Must a Leech Therapist Have?

Has the Patient Been Properly Informed of the Potential Risks of Treatment by the Leech Therapist?

Has the Patient Been Properly Informed about How to Recognize Potential Side Effects?

Do Animal and Environmental Protection Rules Apply?

What Legal Requirements Apply to the Disposal of Medicinal Leeches after Use?

Appendix

Check List: Materials for Leech Therapy

Check List: Leech Therapy Procedure

Pain Journal Used to Document the Results of Leech Therapy

Information for the Patient and Consent Form

Pretreatment Information for Leech Therapy Patients

Leech Therapy Procedure

Index

1 Introduction

A. Michalsen, M. Roth

The return of the traditional treatment practice of leeching, or leech therapy, to modern medicine gave occasion to this book. Today, as was the case in the past, the use of leeches in medicine is drawing tremendous public attention. Positive and negative prejudices about leeches prevail, however these small pro tagonists can face them with great confidence. The fact that leeches have been used for more than 2000 years in the world's most important traditional medicine systems (including traditional European, Ayurvedic, and Chinese medicine) is in itself undeniable proof of the repeated success of leech therapy.

Nevertheless, it is essential to update and scientifically evaluate leech therapy in accordance with the current state of knowledge. According to I. W. Müller:

“Leeching is one of the oldest treatment methods around. It has survived for more than 2000 years since the beginnings of scientific medicine. Leeches were used by the billions, but this extraordinary mass experiment was poorly documented.” [1]

By combining traditional wisdom with modern biological and clinical study data, we can now give precise instructions for optimal leech therapy in hospitals and private practices.

As the title Medicinal Leech Therapy implies, the main objective of this book is to convey the most important elements of the successful practice of medicinal leeching. Apart from mastering the actual technique of leech application, these include a thorough and critical assessment of the indications for leech therapy, as well as a precise knowledge of contraindications and standard procedures for minimizing the risk of treatment complications. An in-depth knowledge of the biology of medicinal leeches (Hirudo medicinalis and Hirudo verbana), as well as skill and sensitivity in the handling of leeches are other important cornerstones of quality assurance.

Seen in a historical context it becomes apparent that there has been a shift in terms of the indications for medicinal leech therapy. In the past, leeches were mainly used to treat heart and circulatory problems, whereas now chronic inflammation and pain management are the primary indications. Over the last few decades, the medicinal leech has regained much of the former significance it had lost over the past 200 years. A century of “vampirism” and abuse, with all the negative consequences and adverse effects associated with it, led to a century of discrimination and general prejudice against leeches.

Today, the therapeutic properties of leeching can be demonstrated from an objective, scientific perspective based solely on the known activity of the specific chemicals in leech saliva. Leech therapy has gained acceptance in modern clinical medicine, initially because of the spectacular results it achieved in plastic and reconstructive surgery and, more recently, because of its proven effectiveness in treating chronic pain syndromes associated with degenerative joint disease.

However, opinions on leech therapy are still divided. On the one hand, stories about the clinical success of hirudotherapy usually generate a (welcome) positive response. On the other hand, problems (side effects, placebo effect, etc.) generally considered to be completely normal and permissible when asso ciated with “clean” pills are frequently blown out of proportion and meet with undue suspicion when they happen to occur with leeches. This ambivalence is understandable considering that the “anonymity” and “sterility” (also in the figurative sense) of most modern remedies, tablets, scalpels, and injection needles contrasts starkly with medicinal leeches, which may seem as exotic or out of place as birds among airplanes.

Consequently, patients apply especially high standards when judging medicinal leeches. Because they literally have close encounters with the leeches, patients are often very concerned and sometimes downright suspicious about the efficacy and safety of leeching. For therapeutic reasons, the leech therapist needs to be able to provide the information needed to allay the patient's treatment concerns. Individuals administering treatments with live animals must have special qualifications. This book aims to provide the theoretical and practical knowledge required to meet these demands. It was written by physicians, alternative practitioners, and biologists mainly for physicians, alternative practitioners, and healthcare workers, but also for biologists and laypersons interested in this subject.

In order to be able to successfully practice leech therapy, we additio nally recommend participating in practical training seminars. Compared to other techniques of natural and complementary medicine, leeching can be learned relatively quickly. Cer tain potential pitfalls can only be identified in the further course of prac tice. Seminars are designed to point out these hazards and, thus, contri bute to optimizing the success of medicinal leech therapy in clinical and private practice. To ensure that leech therapy has a future and continues to be used, full compliance with the essential quality standards must be a top priority for all those administering this form of treatment. When these conditions are met, leeching will continue to be a useful and extremely effective treatment modality used at hospitals and private practices in a presumably ever-growing number of clinical indications.

References

1 Müller IW. Blutegeltherapie zwischen Empirie und Wissenschaft. Erfahrungs-heilkunde 2002; 51(7): 462–471.

2 The History of Leech Therapy

E. Wittke-Michalsen

Leeching is one of the most ancient healing methods documented in the history of medicine. The first clearly identifiable account of leeching appears in ancient Sanskrit writings from India. According to Hindu mythology, Dhavantari, the physician who revealed the secrets of traditional Indian medicine to the world, held nectar in one hand and a leech in the other. The most extensive descriptions of leeching in the Indian literature appear in the writings of the physician Sushruta (100–600 B.C.E.). Leeching was also an ever-present force in traditional Chinese medicine (TCM), but was of lesser significance than in Indian medicine.

In Europe, medicinal leeching was viewed as a science-based therapeutic method right from the beginning. Leeching was an integral part of conventional and folk medicine from antiquity to the 19th century. Medicinal leeching initially remained primarily the domain of empirically minded physicians. Then, most proponents of medicinal leeching deduced its therapeutic efficacy within the framework of the prevailing scientific paradigms of their respective school of medicine. Leeching remained part of various systems of medicine through the centuries. The underlying basis for its use was the widespread belief in the concept of body humors (humoral pathology). This broad concept of disease was based on the notion that all illnesses are caused by an imbalance of one of the four body fluids, or humors (blood, phlegm, yellow bile, and black bile).

Leeching had a fixed and relatively modest range of indications in humoral pathology, the dominant paradigm in ancient European and Arabic medicine until the 17th century. Like bloodletting, leeching was mainly conceived as a means of eliminating the superabundance of blood, or plethora. The other main indications for leeching in early medicine were acute infection, local inflammation, heart problems, and circulatory disorders. Following the decline of humoral pathology, an age of misuse of leeching (“the age of vampirism”) began in the 18th and 19th centuries. Mainly influenced by the teachings of the French physician F. J. V. Broussais (1772–1838), the indications for leech application were extended for no rationally justifiable reason, and leeching was performed at an intensity of hitherto unknown proportions.

In most cases, it is not possible to reliably and accurately translate the historical classification of diseases, their underlying causes within the body, and the corresponding indications for treatment as defined by humoral pathology into the language of modern medicine. Basically, the historical definitions of disease types, constitutional causes, and treatments established based on the humoral concept of disease should be taken metaphorically, similar to the concepts of TCM and Indian medicine that are still present today.

Leeching in Ancient European Medicine

The first detailed description of the therapeutic use of leeches in ancient Greek medicine, which was influenced by Indian medicine, can be found in the poem Alexipharmacia by Nicandros of Colophon (200–130 B.C.E.). However, medicinal leeching first gained true significance in the Methodist School, which differentiated two main causes of disease, e. g. “constriction” and “dilation.” Chronic headache, general febrile conditions, psychoses, epilepsy, ear ailments, liver disease, splenic and intestinal disorders, ischialgia, arthritis, and gout were the main indications for medicinal leeching; general diseases causing symptoms of hardening, heaviness, rigidity, tension, swelling, pain, and cramps (referred to as “status strictus” in the ancient nomenclature) were additional indications. Leeches were regarded primarily as tools for alleviating the tension associated with status strictus.

Advocates of the pneumatic theory of medicine valued leeches as a useful cure for “putrefaction” and “plethora” of blood. The object was to replace “bad blood” with “good blood.” The therapeutic use of leeches became fashio nable and had its first heyday around the middle of the 1st century C.E. An ancient writing credited to the school of the Roman physician Galen (129–199 C.E.) classified leeching as part of the system of elements (fire, earth, air, and water) and temperaments (sanguine, phlegmatic, choleric, and melancholic), the healthy balance of which required the drainage of excess corporal substances. Distinctions were made between plethora (superabundance) and putrefaction of body fluids, as well as between qualitative and quantitative fluid excesses. Plethoric changes were treated by draining blood from the body, which was chiefly achieved by leeching and bloodletting. Disease management strategies were governed by popular beliefs regarding the movement of body fluids. According to the humoral concept of disease, organs or organ systems are not at risk of damage as long as the body fluids remain in motion and are excreted by the natural routes. However, if one part of the body is directly afflicted and the process becomes chronic, it should be treated locally in order to restore the healthy flow of humors. Ancient physicians therefore applied leeches for symptomatic local treatment of febrile and inflammatory diseases. Roman military physicians also used leeches to treat battle wounds.

Leeching in the Middle and Modern Ages

Leeching played a less important role than venesection and cupping in medieval Arabic medicine, where leeches were typically used to treat a variety of skin diseases and illnesses associated with the melancholic temperament (black bile). In Italy, on the other hand, physicians from the school of Salerno used leeches to remove excess body fluids in numerous indications. The teachings of Salernitan physicians gradually spread from Italy across all of Europe.

In the late age of Galenism, medieval physicians also used leeches primarily for “derivation” and removal of harmful fluids directly from an afflicted body part. They believed that the elimination of fluids by leeches promoted “internal combustion” (complete combustion of a body substance by natural organ heat) of residual disease material, thereby promoting natural healing. Leeching, as a simple systemic method for eliminating fluids, was indicated for treating conditions characterized by a general overabundance of fluids (e.g., fever) and could be used instead of venesection. The most important late-Galenic proponent of leeching was Abraham Zacuto (1575–1642), who expanded the range of indications for leeching and established the empirical basis for many physicians of the following years.

In the 17th century, the concept of humoral medicine put forward by Galen had to compete with new medical movements that arose from different streams of reasoning and that had different views on the practice of bloodletting. Proponents of the school of iatrochemistry tended to reject all forms of bloodletting. They believed that any type of blood withdrawal could shorten one's lifetime and that, according to the Holy Scriptures, blood was the locus of the soul and the source of life energy. Since they believed that illnesses developed because the Archeus (the active principle of the body and mediator between body and soul) was infected with an ideo morbus, they reasoned that blood withdrawal would not cure the morbid thought underlying the disease. Still, the majority of iatrochemists continued the different practices of bloodletting with moderate restrictions.

The proponents of iatrophysics had a completely different opinion of medicinal leeching. Influenced by the discovery of the blood circulation, they believed that leeching was practically indispensable. Based on the laws of mechanics, iatrophysicists explained the effects of blood withdrawal in terms of changes in blood pressure, resistance, and velocity in response to bloodletting, resulting in a temporary redistribution of blood within the body with associated effects on the blood vessels, heart, and blood composition. A combination of iatromechanic theories and Galen's humoral concept of disease predominated in 18th century medicine. According to these paradigms, blood is a labile mixture of different substances and is therefore subject to putrefaction. Their proponents believed it was imperative to keep the blood in motion to prevent it from “thickening.” Plethora, which they identified as the major cause of disease, was attributed to an imbalance of food input to blood consumption. Restoration of this balance, they believed, required fasting and physical exercise which, for practical rea sons, frequently could not be performed rigorously and intensively enough to achieve adequate results. Therefore, they had to resort to an imitation of spontaneous bleeding, nature's remedy. The advantage of leeching was that it did not cause asthenia, a frequent complication of venesection and wet cupping. Furthermore, they reasoned that venesection did not eliminate blood effectively from individuals with a sanguine temperament (plethora) or a spongy, fleshy constitution because their blood accumulated mainly in the capillaries. If the superabun-dance of blood was predominantly located in the major blood vessels, as in patients with a choleric temperament, they believed that cupping was inadequate and that leeching was more effective. A special advantage of leeches was that they could be applied to parts of the body that were not amenable to cupping, for example the frontal vein, jugular vein, vessels behind the ears, temporal arteries, and hemorrhoidal veins. Furthermore, leeching was considered to be a specific and dependable remedy for swelling, abdominal cramps, and pain in general, and for rheumatism, arthritis, ischialgia, nephritis, gout, and varicose veins in particular.

F. Hoffmann (1660–1742), a well-known proponent of iatromechanics, used leeches to treat a wide variety of acute disease conditions, as well as for disease prevention. The concept of plethora as a major cause of illnesses associated with thickening of the blood, the related putrefaction of body fluids, and the accumulation of fluids in various organs led physicians to conclude that leeching was an effective remedy for mental illnesses, melancholy, convulsions, pleurisy, asthma, and skin diseases and to implement this form of treatment accordingly.

By the beginning of the 19th century, leeching had become the predominant force in medicine. Because of the extremely high demand, English physicians had to resort to importing leeches from around 1810. This naturally put financial constraints on the spread of medicinal leeching. A leeching boom began in France, which had a rather large natural supply of leeches, and soon spread throughout all of Europe. Leeching was preferentially used instead of phlebotomy in almost all indications. The art of leech application became a profession in itself.

“The leader of this movement was F. J. V. Broussais (1772–1832), who proposed a new system of ‘physiological medicine’. Broussais attributed nearly all illnesses to inflammation, and he believed that pathological changes in the capillary system of tissues were a key factor in these processes.” [4]

Since inflammations were thought to arise mainly in the capillary vessel territories and, since leeches primarily withdraw blood from the capillaries, leeching was administered as a universal cure, especially for abdominal diseases. Broussais combined older theories of medicine with the newer concepts of excitation and depression proposed by Brown (1735–1788), who believed that all diseases result from an excess (sthenia) or lack (asthenia) of stimulation and excitation. Broussais believed it was necessary to withdraw blood when there was excessive vital energy or an excess of blood-forming substances in the diet. According to Broussais, blood surplus causes excessive strength or excitation, which manifests itself as fever, inflammation, congestion, spasms, and pain. Furthermore, it can also cause asthenia indirectly by preventing blood flow, leading to diseases such as apoplexy, asthma, and mental illnesses. Basically, virtually any disease could be classified as an indication for leeching depending on which medical paradigms were applied.

In the Broussaian age, the practice of leeching soon became so excessive that some of his contemporaries referred to it as “vampirism” (see Fig. 2.1). Up to 100 leeches were used in a single session, and several million lee ches were used annually in countries like France, England, and Germany. “Broussaisism,” as medicinal leeching was called for a while, inspired the “robes à la Broussais” design, a paisley-like depiction of the leech used to decorate garments worn by the women of society [1]. The French soon exhausted their supply of leeches, especially since the natural habitats of the leech had been continuously diminished due to agricultural and industrial use. Increasing numbers of leeches had to be imported. By 1828, leeches had become the most important article in the Materia Medica, and roughly 100 million leeches were used each year in France alone. The price of leeches rose dramatically. Many physicians were therefore in favor of reusing old leeches and attempted to grow them in breeding facilities annexed to hospitals. Leech breeding was financed by the government, and military physicians were particularly worried that a shortage of leeches might affect their ability to treat battle injuries.

Fig. 2.1 “Another 90 leeches, please!” Early 19th century caricature [7]

Leech Therapy in Recent Times

Around 1850, the practice of leeching gradually began to decline. This was partly due to the fact that leeches had by then been virtually exterminated in Central Europe and had to be imported from Central Asia, making them quite expensive. The main reason, however, was that the concept of cellular pathology introduced by Virchow (1821–1902) in the mid-1850s cast serious doubts on the older concepts of disease previously used as the justification for bloodletting. The subsequent discovery that diseases were caused by bacteria led to a virtual explosion of bacteriophobia. The use of leeches then dropped off rapidly, especially at hospitals. It was not possible to disinfect or steri lize leeches without killing them. Since medical education now took place in hospitals, physicians in training were rarely ever introduced to leech therapy, and this form of treatment fell into oblivion.

A major event in the history of medicinal leech therapy was the discovery by J. B. Haycraft (1857–1922) that the mouth and throat of the leech contained a substance that prevented the blood from coagulating; the compound was isolated and named hirudin in 1903/04. The specific effects of leeching could now be defined as a chemical process, that is, as a rational principle more closely in conformity with the conventional concepts of mo dern medicine and science. However, news of the recent discovery spread slowly—initially only among the scientific research community—and only the chemical compound itself attracted attention. The primary expectation of researchers was that this anticoagulant might have potential benefits in blood transfusion or that hirudin extracts might be useful in the treatment of thrombosis, embolism, and infarction. However, the exorbitantly high costs of extracting the compound were too prohibitive for widespread use. The anticoagulant effect of hirudin was first noted in clinical/practical work nearly 25 years after the discovery of the compound. However, World War I and the resulting collapse of the leech trade pushed medicinal leech therapy once again into oblivion.

Leech therapy experienced a stronger revival in the 1920s. B. Aschner (1883–1960), a member of the group of naturopathic physicians, was then the main proponent of leech therapy. While developing his concept of constitutional therapy, he remem bered the old bloodletting techniques and expounded them from new perspectives which, however, were strongly influenced by the humoral concept of pathology. The list of medical indications for leeching grew long again, and this uncritical use of the technique pushed leeching into the ranks of the so-called panaceas.

A specific domain of leech therapy was soon to be developed by the surgeon Termier. As the potentials of surgery increased, thrombus and embolism started to become more and more frequent postoperative complications. Termier remembered reading about the anticoagulatory effect of hirudin. Since it was too expensive to extract the drug, he recommended the direct application of leeches in 1922 so that hirudin could then be injected by the natural route. Termier called this technique “hirudinization of the blood.” Within a few years, all renowned hospitals in Europe had started using leeches again for this medical indication.

“After its publication in 1935, H. Bottenberg's book—the first comprehensive description of this treatment modality in modern times, the greater part of which conforms to the needs and mindsets of practical physicians and which provides 52 vivid case reports demonstrating its success—fell on fertile ground. It remained a standard work for several years and is (and was) internationally acclaimed.” [4]

The plethora of indications for leeching was still too extensive. Bottenberg established the following general indications for leech therapy:

• All inflammatory processes and rheumatic diseases

• Passive congestions and spastic conditions

• Antidyscratic therapy (blood purification and regeneration) of toxicoses and mental illnesses

• Thrombosis and embolism

• Transudates and exudates

• When venesection is not possible for technical reasons (e.g., childhood, obesity, or joint contracture) or when treatment of a specific vessel territory is desired

Based on the scientific literature, Bottenberg also compiled a list of mechanisms of action, which was uncritically accepted by his imitators.

Once heparin and phenprocoumon (Marcumar) established themselves as the agents of choice for treatment and prophylaxis of thrombosis and embolism after World War II, the leech again disappeared from most hospitals in Central Europe and was also increasingly forgotten by practitioners.

In the 1970s, medicinal leech therapy achieved a remarkable international comeback thanks to the increasing use of leeches in the fields of general, plastic, and reconstructive surgery for treatment of postoperative venous congestion and graft rejection. Leech therapy simultaneously became increa singly popular in modern naturopathic circles in German-speaking regions. The reported successes of hirudotherapy in the context of naturopathic pain management and the results of several scientific studies by researchers from various university naturopathic departments on the effectiveness of leech therapy in the treatment of symptomatic joint diseases have since been widely received.

References

1 Arndt W. Die Rohstoffe des Tierreichs – Als Heilmittel gebrauchte Stoffe. (Bd. 2. Blutegel). Berlin: 1940.

2 Aschner B. Technik der Konstitutionstherapie. 7th ed. Heidelberg: Haug: 1995.

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3 The Biology of Leeches

M. Roth

Introduction

Roughly 600 leech species have been identified to date, but only about 15 are used in medicine. Leeches classified as “medicinal leeches” in the narrower sense have been used to treat patients around the world, especially in Europe and the United States, for centuries. Because of its excellent therapeutic properties, the medicinal leech described here is considered to be the favorite species. In the past, the medicinal leech was generally assumed to be a single species with regional color differences. Based on this logic, the two phenotypes with the most distinctive coloring were originally named Hirudo medicinalis medicinalis and Hirudo medicinalis officinalis (Fig. 3.1a, b). The latter, which is also known as the “Hungarian leech,” was later renamed Hirudo officinalis after it was given species status. According to current scientific understanding, the different patterns on their body surfaces indicate that the two presumed phenotypes are indeed two different species: Hirudo medicinalis Linnaeus, 1758 and Hirudo verbana Carena, 1820. The species concept was recently proved by DNA analysis [26].

In leech therapy, the existence of two species seems to be irrelevant because both have been used as equivalents throughout history. As far as can be determined, no differences in their spectrum of activity are known or have ever been investigated. The composition of their saliva is also identical [24]. Since the natural supply of Hirudo medicinalis