Leeches offer vein hope

Thursday, 24 September, 1998

Leeches have been used successfully to treat varicose veins. New Scientist reports that doctors in India have used the blood-sucking worms to cure the leg ulcers and swelling that result from the condition. The doctors, at the KEM Hospital and Seth Medical College in Bombay, used the treatment on 20 patients.

Clinical trial success

They said it cured ulcers in all the patients and reduced serious swelling in 18 of them. The researchers said that the treatment works because blood in veins has had the oxygen removed. Leeches prefer this venous blood to the oxygen-rich blood carried in arteries, they said. Varicose veins are veins that have been stretched and grow out of proportion to the blood they have to carry.

Malfunctioning veins

The condition, which affects about two-thirds of adults in the UK, occurs when valves in the veins malfunction. Conventional treatment involves surgery to remove the problematic vein or else injections of a substance that causes the vein to scar and close. Sometimes both treatments will be used. Leeches have been making a comeback in the medical world of late. Research in the US recently showed that a chemical derived from the creatures could help reduce deaths and heart attacks in people suffering coronary heart disease.

Multipurpose bloodsuckers

Leeches are particularly useful in plastic surgery, such as breast reconstruction and where a part of the body has become severed and had to be sewn back on. Sometimes, the patient's veins are too weak to carry blood and it builds up, causing "venous congestion". Attaching leeches to the body draws the blood away gradually and painlessly since leech saliva contains an anaesthetic. Leeches were widely used up until this century for many medical conditions, including tonsillitis and piles.

Doctors say they fell out of use because they were being applied too much and in the wrong way.
But leeches are becoming big business as doctors go back to their roots. Biopharm, a leech farm in Wales, provides the NHS with 15,000 leeches a year and ships another 15,000 around the world. Marian Bower, the farm's manager said business is booming. "We started as a small company in Wales. Now we have distribution offices around the world and are about to open another in South Africa," she said.

(http://news.bbc.co.uk/1/hi/health/179227.stm)

Leech Therapy

Thursday January 22, 2004

A study published in the Annals of Internal Medicine journal suggests that leeches may relieve pain better than topical anti-inflammatory treatments. Patients in the study were required to allow the blood sucking leeches to be attached to the ailing area 70 minutes a day for up to 90 days.

http://biology.about.com/b/2004/01/22/leech-therapy.htm

Leech Treatment: MOUTH

Clinical Policy Bulletin: Medicinal Leech Therapy

Policy Number: 0556

Aetna considers medicinal leech (Hirudo medicinalis) therapy medically necessary for any of the following conditions:

• Poor venous drainage (venous congestion/venous outflow obstruction); or
  

• Salvage of vascularly compromised flaps (muscle, skin, and fat tissue surgically removed from one part of body to another); or

• Salvage of vascularly compromised replants (limbs or other body parts re-attached after traumatic amputation).
  

Aetna considers medicinal leech therapy experimental and investigational for treating knee osteoarthritis, inadequate arterial supply or tissue ischemia, and for all other indications.


Background

The medicinal leech, Hirudo medicinalis, has been used increasingly for relief of venous congestion, especially for salvage of compromised pedicled flaps and microvascular free-tissue transfer, digital re-implantation, and breast reconstruction. Leech therapy for compromised flaps is best used early since flaps demonstrate significantly decreased survival after 3 hours if venous congestion is not relieved. If venous pooling occurs around a flap or replant, the skin becomes cyanotic, cool, and hard. If capillary refill time (CRT) remains more than 3 seconds the flap or replant will not survive. The objective of leech therapy is for the affected area to become pink and warm, with a CRT of less than 2 seconds.

When leeches begin feeding, they inject salivary components (e.g., hirudin) that inhibit both platelet aggregation and the coagulation cascade. This results in a marked relief of venous congestion. The anti-coagulant causes the bite to ooze for up to 48 hours following detachment, further relieving venous congestion. By feeding for 10 to 60 minutes, leeches consume from 1 to 2 teaspoons of blood. Results from clinical studies showed that the success rate of salvaging tissue with medicinal leech therapy is 70 to 80%. On June 28, 2004, the Food and Drug Administration (FDA) had for the first time cleared the commercial marketing of leeches for medicinal purposes (in skin grafts and reattachment surgery).

Recently, leech therapy has also been suggested to be an effective treatment for rapid reduction of pain associated with osteoarthritis of the knee (Michalsen, et al., 2002). However, its effectiveness in treating osteoarthritis (OA) of the knee needs to be validated in larger randomized controlled studies. In a follow-up randomized controlled study, Michalsen, et al. (2003) evaluated the effectiveness of leech therapy for symptomatic relief of patients with OA of the knee (n = 51). Patients received a single treatment with 4 to 6 locally applied leeches (leech therapy group) or a 28-day topical diclofenac regimen (control group). The primary end point, pain at day 7, was reduced from a mean (+/-SD) of 53.5 +/- 13.7 to 19.3 +/- 12.2 after leech therapy compared with 51.5 +/- 16.8 to 42.4 +/- 19.7 with topical diclofenac. Although the difference between group pain scores was no longer significant after day 7, differences for function, stiffness, and total symptoms remained significant in favor of leech therapy until the end of study and for quality of life until day 28. The authors concluded that leech therapy helps relieve symptoms in patients with OA of the knee. The potential of leech therapy for treating OA and the pharmacological properties of leech saliva remain to be clarified.

In an editorial that accompanied the article by Michalsen, et al., Hochberg (2003) discussed some of the drawbacks of this paper. A lack of blinding of the patients as well as the researchers is a major pitfall because it raises concerns regarding measurement bias, especially since the outcome measures were all subjective. Also, 7 days is a short time frame for measuring the primary outcome measure since OA is a chronic condition. Furthermore, patients in both groups seldom used rescue therapy, suggesting that, despite the observed significant differences in pain scores at day 7, both groups may have been satisfied with their responses to study interventions. Thus, it is still unclear whether leech therapy is effective in treating knee pain in patients with OA.

Medicinal leech therapy is usually carried out for 4 to 5 days for patients with replant; it may be performed for 6 to 10 days for patients with compromised flaps.

A complication of leech therapy is the risk of infection; thus, it is recommended that therapy not be used in the presence of non-viable tissue.

Patients with HIV infection, or individuals taking immunosuppressive medications should not undergo leech therapy because of the risk of overwhelming bacterial sepsis.

The above policy is based on the following references:

• Voge C, Lehnherr SM. Leeches. Nursing. 1999;29(11):46-47.
  
• Utley DS, Koch RJ, Goode RL. The failing flap in facial plastic and reconstructive surgery: Role of the medicinal leech. Laryngoscope. 1998;108(8 Pt 1):1129-1135.
  
• de Chalain TM. Exploring the use of the medicinal leech: A clinical risk-benefit analysis. J Reconstr Microsurg. 1996;12(3):165-172.
  
• Haycox C, Odland PB, Coltrera MD, Raugi GJ. Indications and complications of medicinal leech therapy. J Am Acad Dermatol. 1995;33(6):1053-1055.
  
• Michalsen A, Moebus S, Spahn G, et al. Leech therapy for symptomatic treatment of knee osteoarthritis: Results and implications of a pilot study. Altern Ther Health Med. 2002;8(5):84-88.
  
• Michalsen A, Klotz S, Ludtke R, et al. Effectiveness of leech therapy in osteoarthritis of the knee: A randomized, controlled trial. Ann Intern Med. 2003;139(9):724-730.
  
• Hochberg MC. Multidisciplinary integrative approach to treating knee pain in patients with osteoarthritis. Ann Intern Med. 2003;139(9):781-783.
  
• U.S. Food and Drug Administration (FDA). FDA clears medicinal leeches for marketing. FDA Talk Paper. T04-19. Rockville, MD: FDA; June 28, 2004. Available at: http://www.fda.gov/bbs/topics/answers/2004/ANS01294.html. Accessed June 30, 2004.
  
• Frodel JL Jr, Barth P, Wagner J. Salvage of partial facial soft tissue avulsions with medicinal leeches. Otolaryngol Head Neck Surg. 2004;131(6):934-939.
  
• Whitaker IS, Cheung CK, Chahal CA, et al. By what mechanism do leeches help to salvage ischaemic tissues? A review. Br J Oral Maxillofac Surg. 2005;43(2):155-160.
  
• Durrant C, Townley WA, Ramkumar S, Khoo CT. Forgotten digital tourniquet: Salvage of an ischaemic finger by application of medicinal leeches. Ann R Coll Surg Engl. 2006;88(5):462-464.
  
• Knobloch K, Gohritz A, Busch K, et al. Hirudo medicinalis-leech applications in plastic and reconstructive microsurgery--a literature review. Handchir Mikrochir Plast Chir. 2007;39(2):103-107.
  

(Source: http://www.aetna.com/cpb/medical/data/500_599/0556.html)