Leech therapy indications:a scoping review

Roshanak Ghods,Mojtaba Abdi,Matineh Pourrahimi,Fataneh Hashem Dabaghian

1Research Institute for Islamic and Complementary Medicine,Iran University of Medical Sciences,Tehran,Iran.

2School of Persian Medicine,Iran University of Medical Sciences,Tehran,Iran.

3School of Nursing and Midwifery Branch,Iran University of Medical Sciences,Tehran,Iran.

4Faculty of Allied Medicine Branch,Iran University of Medical Sciences,Tehran,Iran.

Abstract

Keywords: Leeches,Leech therapy,Review,Plastic and reconstructive surgery,Musculoskeletal diseases,Osteoarthritis

Background

The word "leech" means a physician,derived from an Anglo-Saxon word (laece) [1].The leeches are from the ringworm branch (Phylum: Annelida) in Clitellata Class because a genital belt is near their gonads.These worms belong to the Hirudinea sub-class which are bloodthirsty and hermaphrodite and they have suction at their two ends.Their mouth is in the anterior and thinner sections and their connector disk is in the posterior and wider part of their body.Their mouth has three jaws.When the leech bites the body of the host,it leaves a Y shape wound,and in this case,it injects various compounds that were made by its salivary glands [2-4].The region of leech bites,due to its anticoagulant properties,can bled for hours[5-8].

Medicinal leeches (Hirudo Medicinalis) have a long history.From the cave paintings in ancient Egypt more than 3,500 years ago,until the Persian,Arabic,China,Greek,Byzantine,and Sanskrit writings in the first century A.D..The first recorded report of the use of leeches is in a medical poem,Alexipharma,for Nicander of Colophon,born 200 B.C.[9-11].There is also evidence of the using leeches by large scholars such as Avicenna inThe Canon of Medicine[12] and Abd-el-Latif al-Baghdadi inAl-Mukhtarat fi al-Tibb[13].After the development of modern medicine,the use of leeches was gradually forgotten,but in the late nineteenth century,leeches were still used in many countries of the world [14].The first use of medical leeches occurred in the 1960's,for intravenous congestion after reconstructive surgery [15].In 2004 the FDA approved leech therapy to accelerate tissue transplantation [16].Up to now,the leech has been used to treat a wide range of diseases (Video 1),for its therapeutic properties associated with more than 100 active substances in its salivary glands which injected into the host tissue during sucking[17-24].

Due to the importance of this issue and the need to address a scientific approach to leech therapy,the purpose of this study was to search and review articles related to the common use of leech in various diseases treatment.

Methods

Search strategy

The present study is a scoping review of the evidence of the indication of leech therapy which its proposal was approved by the Institute of Islamic Medicine,Iran University of medical sciences on October 18,2016,No.88.The results of this study are based on English articles and dissertation published in databases such as Ebsco Host (All academics Version),Ovid,ProQuest,PubMed,Science Direct,Scopus,Web of Knowledge(Full Access) and Wiley and Google Scholar (as a search engine).The articles were related to our topic gathered and reviewed.The time frame for the search of articles was up to July 10,2017,and because of using new findings publications below 2000 were omitted from this study.

At first,the standard keyword and its equivalents were extracted from the MESH.Then,in the PubMed,pilot search was performed to discover more keywords for writing search strategy by using Leech,Leeche,Leech Therapy,Leeching,Hirudinea,Hirudineas,Hirudo therapy and their equivalents,along with their expected combined forms,with the help of appropriate operators of the site.After identifying all the equivalent terms and all the combinations of words a search strategy was written and a strategic search was carried out at all of the sites mentioned.The articles were probed independently by two members of the research team for increasing accuracy and precision in the search.Finally,all of the articles were merged into one another.The search strategy is mentioned in the appendix.

Papers selection

This stage was conducted by two members of the research-team work and in case of disagreement,the third person gave the final comment.At the first step,duplicate articles were deleted.Then valid articles were separated from the news,the pages of public journals,newspapers and other non-authoritative sources,as well as articles in the form of posters or lectures because of inability to evaluate the internal validity of the research.Next,valid sources extracted were categorized by subject.In the next step,the abstract part of the articles was reviewed.Then,the full text of the articles with our desired characteristics was extracted through an access to the Central Library of Iran University of Medical Sciences.In order to get the full text of the inaccessible articles through this library,emails were sent to the authors of the articles.Then the entire texts of articles were studied and the final papers which were absolutely related to our study were selected to use in this study.The EndNote Ver.X7 software was used to manage articles.The paper flow is shown in Figure 1.

Data extraction

The findings of the articles and related items together with their reference were collected separately for each category.After reading all the selected articles and searching the citation of each paper,the materials were summarized and used in the text of the article.

Results

Researches showed that leech therapy is used in the following conditions in the world:

Plastic and reconstructive surgery

Figure1 The papers flow chart

Table1 Plastic and reconstructive surgery

Venous congestion is known as a common complication after plastic and reconstructive surgery,resulting in tissue loss and failure of the transplant.In this study,34 articles were found that leech therapy has been used after various reconstructive surgeries (Table 1).

Out of 428 cases,75 cases were related to the transplant which include ears[37,40,56,57],nose[34,41],lips [36,38,50],eyebrows [35],tongue [42],thumbs and fingers [30,33],penile [32,44,49] and nipple [58].Of the 428 cases,62.6 percent(268 cases)achieved treatment success.

Another application of leech therapy in reconstructive surgery is salvage of tissue avulsions.Although the use of leeches in these conditions is unusual,in three studies,leech therapy is used when arterial inflow was adequate yet venous outflow was not and all 7 cases were treated[47,48,54].

Musculoskeletal diseases

9 related articles were found (Table 2) and 7 of them focused on the use of leeches in order to treat knee osteoarthritis.One study reported that after application of leeches,rapid relief of pain was observed in all patients.This patients' pain score was reduced from an average score of 4.7 in the Visual Analog Scale(VAS)to 1.3 meaningfully and remained stable for 4 weeks after treatment [59].A similar study was conducted to compare leech therapy with the use of topical diclofenac in patients with knee osteoarthritis.The mean pain score in the leech therapy group and the diclofenac group respectively reduced 39.9 and 7.7 scores in pain scales of the Western Ontario and McMaster Universities Osteoarthritis Index visual analogue scales [60].In another study,pain relief was not significantly different with a double application of leeches,but both groups had a significant reduction in pain compared to the control group.The results showed improvement in stiffness and function in a double application with the leeches [61].Improvement in disease-specific symptoms after leech therapy was reported by other studies that confirming the previous findings[62-65].

There is a research,aimed to treat symptomatic arthrosis of the first carpometacarpal joint.In this study,one application of leeches was compared with topical diclofenac.The mean of pain score in the VAS reduced from 50.6±13.3 to 46.9±18.5 in Topical diclofenac and from 59.6±13.8 to 27.1±20.6 in leech group (P＜0.0003)during 7 days.Grip strength of the thumb joint (lateral pintch power) which was performed by an electronic device,significantly increased too[66].

Also,there is a similar article dealt with chronic epicondylitis.During 45 days,the mean scores from 3 visual analog scales for pain during motion,grip,and rest decreased strongly in the leech group comparing with topical diclofenac[67].

Cardiovascular diseases

In the field of cardiovascular disease,there are 2 articles focusing on blood coagulation.The research reported that symptoms in over 50% of chronic heart failure patients improved using standard treatment combined with leech therapy.The diastolic pressure decreased and ejection fraction increased in hypertensive patients.Platelet aggregation reduced and fibrin monomer complexes normalized[68].In another study,leech therapy was used to treat patients with deep vein thrombosis[69].

Leeches also were applied for neurological disorders caused by ischemia.It was showed that patients with transient ischemic attack(TIA) receiving leech therapy combined with routine treatments,less re-TIA occurs within one year after treatment [70].Another research also showed that leech therapy caused a significant decrease of ear noise and the maintenance of the tendency toward further improvement of cochlear and vestibular functions in patients with peripheral cochleovestibular disorders[71].

Migraine headaches

There is a non-randomized clinical trial including two groups of patients with migraine headaches.One receiving leech therapy and the other receiving routine drug therapy (Propranolol 80 mg/day and Amitriptyline 50 mg/day).Patients were followed up one week,one month,two months and three months after the intervention.The result indicated leech therapy had the same effect as medication to relieve migraine headaches and it could reduce severity and duration of a headache significantly for at least three months[72].

Skin disorders

2 articles were found related to using of leeches for skin disorders.It is showed that leech therapy can reduce erythema,thickness,scratching and lichenification in patients with dermatitis.The total scores of EASI and SCORAD decreased and the patients' quality of life increased [73].A case of a patient with Nevus of Ota receiving leech therapy also showed significant improvement in the skin color[74].

Diabetic foot ulcers

3 articles reported using of leech therapy as a treatment for diabetic foot ulcer (DFU).In a case report of a patient with 4 DFUs grade 5 receiving leech therapy caused completely improvement of the pain,wound,and deformity of the patient's leg.The diabetic foot saved from amputation and the patient could walk finally.However antiseptic and deobstruent drugs besides leech therapy and unripe papaya dressing helped in the process of healing [75].Other cases of DFUs which perfectly improved by leech therapy showed in table 2[76,77].

Table2 Papers at a glance

CHF,Chronic heart failure;DVT,Deep vein thrombosis;TIA,Transient ischemic attack;DFU,Diabetic foot ulcer.

Macroglossia

2 articles founded in this issue.They focused on macroglossia caused by edema and hematoma.One case of macroglossia caused by damage and ecchymosis,was treated with leeches,although previously,routine treatment did not work.As the result of the 24-hour treatment process,a significant reduction in the size of the tongue occurred [78].In another case of a progressive macroglossia after blunt trauma,it rapidly improved by leech therapy[79].

Priapism

Leech therapy was used in order to treat priapism in a 26-year-old patient without a history of certain diseases.After two days,the pain was significantly reduced,although the patient still had cavernosal swelling and tenderness to palpation.Finally,the pain and perineal swelling completely healed after one month[80].

Cancer

2 articles were conducted on the effect of hirudo medicinalis.There was the case of a male patient with synchronous renal cell carcinoma and leiomyosarcoma with severe pain in the lumbar region which was refractory to radiotherapy,and systemic and epidural analgesic infusion.The pain healed completely by using leeches on the lumbar region [81].Also,leech therapy improved penoscrotal oedema due to hormone-refractory prostate carcinoma in another case[82].

However,there are two other species of leeches were taken into consideration that these articles refer to:

Haementeria ghilianii:The substance in the saliva of this leech called Ghilanten,was considered by researchers in 1995.The results showed Ghilanten or the saliva of this leech had antitumor effects without obvious side effects in vivo and in vitro.This effect involves the inhabitation of cell proliferation and reduction of apoptosis by the individual's own immune system and reducing cell-to-cell binding and inflammation[83].

Haementeria ghilianii: There are 7 patents for the use of a whole,leech saliva extract for cancer treatment but no article has been published to prove the effectiveness of this leech so far,and it is only a scientific claim.These patents claimed the effect of leech saliva on cancer treatment,including lymphoma,melanoma and colorectal,pancreatic,kidney,prostate,ovarian and breast cancer[84-89].

Wound

The effect of leech therapy on linear incisional skin-wound was examined in an experimental study.Wounds of about 2 cm in the same depth were made on dorsolateral region of 15 male rats.They were divided into three groups.The first group was treated daily with topical phenytoin 1% while the second group received leech therapy once at the beginning.The control group had neither medications nor leech therapy.Survey of 3th and 7th days of the experiment pointed out hair growth in the wound area was better in the leech therapy group,and the completely covered it during the 7 days.Also,the wounds completely healed in pathological studies.Generally,the superficial wound appearance represents a significant impact on wound healing in the group of leech therapy[90].

Discussion

This study was designed to provide leech therapy indications.The results of this study showed leech therapy is used in different conditions in the world including venous congestion in plastic and reconstructive surgery,osteoarthritis,cardiovascular diseases due to blood coagulation disorders,migraine headache,skin disorders,diabetic foot ulcers,macroglossia,priapism,cancer complications,and wounds.These findings were extracted from articles published from 2000 up to July 10,2017.As the results show,articles related to plastic and reconstructive surgery with the quantity of 34,has the highest number of published articles.Subsequently,musculoskeletal diseases with 9 published articles are ranked second in this topic.However,knee osteoarthritis with 7 articles of 9 has more evidence than other musculoskeletal diseases.In the third place,there are articles related to cardiovascular diseases.Articles about diabetic foot ulcers,macroglossia,cancer complication,priapism and Nevus of Ota were case reports.

A noteworthy point in this study is the similarity of some of these indications published in recent decades with those recommended in the traditional medical literature,belonged to more than 10 centuries ago.Leech therapy for the treatment of arthritis pain,types of headache (hot headache) [91],skin diseases such as psoriasis (a kind of eczema commonly known as"Guba"or"Da’Alsdf"in Iranian traditional medicine)and erysipelas (a kind of dermatitis commonly known as "Al-Hamreh" in Iranian traditional medicine),decrease venous congestion in varicose veins of legs and healing of variety of wounds ("Sa'feh" and"Balkhieh")has been mentioned in the Ibn-Sina's bookThe Canon of Medicine[12].It was found that there is still a large number of well-documented and fully accepted indications for the treatment of diseases in traditional medicine books that have not been investigated.These include visual impairment (placing leeches on temples),spot baldness (Alopecia areata),discolored skin patches,various types of rashes and boils,hemorrhage (placing leech around the anus),etc[12].

The limitations of this research are the lack of randomized controlled trials in humans and few numbers of samples,case reports on the use of leeches for patients,lack of reliable protocol for leeches,high heterogeneity of articles and lack of a proper checklist to check their quality together.

Conclusion

Due to the few numbers of studies in many of these areas and the inadequate methodological quality of some of them,including the small samples,lack of a control group,and the presence of more articles in the lower levels of the evidence pyramid,it seems that more research is needed in wider areas with more precise methodologies in order to ensure the potential therapeutic effects of this little creature recommended repeatedly to use it in various diseases from the past and in ancient medical texts.Although these numbers of evidence that were similar to those recommended in ancient medical texts which they mostly are successful are incentives for researchers to pay more attention to other leech therapies suggested by older scholars.Maybe we can reach less costly and faster and more effective treatments with leech therapy.