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Three Part Question

Does [hirudotherapy/leeches] reduce [traumatic tongue swelling/macroglossia] faster than [steroids]?

Clinical Scenario

A 49 year old man with known alcoholic liver disease attended the ED, unwell. While in the ED he had a fit and bit his tongue. He only had a platelet count of 28 and so developed massive tongue swelling, which obstructed his airway. He had an emergency tracheostomy and has been sedated and ventilated. He will be transferred to ICU. The ENT surgeon asks for dexamethasone to be started to reduce tongue swelling. As the tongue swelling is caused by a large haematoma you wonder whether he would benfit more from the application of leeches (hirudotherapy)?

Search Strategy

Medline 1946-September week 1 2013
[leeches.mp. or exp Leeches/ OR exp Hirudo medicinalis/ or hirudotherapy.mp.] AND [macroglossia.mp. or exp Macroglossia/ OR tongue swelling.mp. OR swollen tongue.mp. OR lingual haematoma.mp. OR sublingual haematoma.mp.]

Search Outcome

The Medline search revealed 1 review and 3 case reports. A search using PubMed (leeches and haematoma)produced another case report and several general reviews.
There are no Cochrane Reviews relating to leeches or hirudotherapy.Serendipitous searching of the internet revealed 1 systematic review of leech use in plastic surgery and 2 further case reports.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Whitaler et al. 2012 UK	Studies evaluating leech therapy for venous congestion of surgical flaps and replanted appendages.	Systematic review of 27 case series and 38 case reports (277 patients in total). There were no RCTs.	Success of therapy (survival of tissue or flap)	Success achieved in 216/277 (78%) vs 61/277 (22%).
			Required blood transfusion	50% of cases where this outcome was reported.
			Complications	50/229 (22%)
			Infection	33/229 (14%)

Comment(s)

Leeches (Hirudo medicinalis) have been used medicinally for thousands of years (Whitaker et al, 2004). Their use only stopped in the mid-nineteenth century. Advances in plastic and reconstructive therapy, with the attendant problem of venous congestion of flaps and re-implanted digits and other structures, have prompted renewed interest and use of Hirudo medicinalis (Whitaker et al, 2012). Hirudo medicinalis secretes a peptide called hirudin from its salivary glands, which is vital to sustain the animal's haematophagy as it prevents clot formation when feeding. Hirudin is biologically active in a similar way to antithrombin III, in that it inhibits the procoagulant properties of thrombin, while also disrupting thrombin complexes. This results in hirudin having the ability both to act as an anti-coagulant and also a thrombolytic agent. Leeches can easily be ordered from specialist suppliers (found via the internet). A leech has three jaws, each with approximately 100 teeth, but to utilise this 300-tooth bite, one must ensure the leeches are hungry (small and thin). Hirudo medicinalis may feed for up to an hour, depending on how hungry it is. Once applied, leeches should be kept under regular observation and a dressing should be applied around the area to discourage unwanted migration (such as down the alimentary/respiratory tract). Handy tip: they can be tethered with a suture through the tail. Once removed, with a flat object to break the suction, the wound will bleed. In addition to hirudin, a potent inhibitor of collagen-mediated platelet aggregation called calin (Munro et al, 1991) is released. This bleeding will continue and contributes to the reduction in haematoma size post-application of your leech. Prophylactic antibiotics should be considered as there is a risk of infection from microorganisms, such as Aeromonas hydrophila (Sartor et al, 2013).

Clinical Bottom Line

Leeches can be effective in reducing venous congestion in plastic and reconstructive surgery procedures. They may also be effective in reducing the size of a lingual haematoma.

References

1. Whitaker IS, Oboumarzou O, Rozen WM, Naderi N, Balasubramanian SP, Azzopardi EA, Kon M. The efficacy of medicinal leeches in plastic and reconsructive surgery: a systematic review of 277 reported clinical cases. Microsurgery 2012; 32: 240-250.
2. Sartor M, Bornet C, Guinard D, Fournier P. Transmission of Aeromonas Hydrophila by leeches. The Lancet. 2013; 381(9878): 1686-
3. Munro R, Jones CP, Sawyer RT. Calin – a platelet adhesion inhibitor from the saliva of the medicinal leech. Blood, Coagulation and Fibrinolysis. 1991; 2(1): 179-84.
4. Whitaker IS. Rao J. Izadi D. Butler PE. Historical Article: Hirudo medicinalis: ancient origins of, and trends in the use of medicinal leeches throughout history. The British journal of oral & maxillofacial surgery 2004; 42(2):133-137.