P. Flecken, A. Michalsen

Venous disease is one of the best-established traditional indications for leech therapy. There is a plethora of case reports and empirical studies on the subject, including clinical investigations of the efficacy of leeching for postoperative prevention of thrombosis before the advent of heparin, which is now the standard prophylactic agent. The postoperative use of leeches for prevention of thrombosis was proposed by the French surgeon Termier as far back as the 1920s. His recommendation was first adopted in France and was later implemented successfully in numerous hospitals around the world. In addition to its fibrinolytic and viscosity-enhancing effects in the blood, leeching also has bactericidal and some spasmolytic activity that may have a very positive effect on the patient’s general condition. Leeching was therefore a permanent institution at many hospitals for many years and was readily performed even though it was relatively time-consuming in terms of changing the dressing and caring for the animals.

In the end, comparative studies from this period were unable to demonstrate that leech therapy could reliably prevent thromboembolism. This was presumably due to the unreliable pharmacokinetics and poorly controll able anticoagulatory effects of leeching. After the advent of heparin, leeching rapidly lost its foothold in thrombosis prophylaxis and is no longer used for this indication today. In deep vein thrombosis, the systemic effects of leeches are insufficient; hence, it must be assumed that they do not have any relevant systemic fibrinolytic activity. In modern medicine, the use of leeches for adjuvant treatment of acute deep leg vein thrombosis cannot be justified because the established drugs used for initial anticoagulation constitute a contraindication for leeching.

Spider-burst must be differentiated from symptomatic varicose veins. Most patients seeking treatment for this mainly asymptomatic form of venous dilatation are women expecting cosmetic improvement. Leech therapy can, in fact, improve the cosmetic appearance of spider-burst veins, but there are no reliable data for objective quantification of the treatment results. As with CVI, it is important to inform patients with spider-burst veins that leeching often does not change the appearance of their condition and that the leech bites can even result in small scars or depigmentation.

In most cases, leech application has a significantly positive effect on the course of superficial phlebitis. Patients often perceive a noticeable improvement of symptoms right after treatment. Due to the potent anti-inflammatory, blood-thinning, and lymph flow–accelerating effect of leech secretions, the symptoms of swelling and pain rapidly subside, and the local letting of blood has a decongesting effect in the affected region.

In acute phlebitis, our experience has shown that the application of a lar ger number of leeches in a single session achieves the best results. In chronic venous disease, on the other hand, it is better to apply a smaller number of leeches in a series of treatments.

Target sites for leech application must be identified while the patient is standing to ensure that the blood vessels are in their maximum filling state. Leeches should never be applied to a visible or palpable vein, but always perivenously, that is, slightly proximal or lateral to the vein. Once the target sites have been identified, the leeches can be applied while the patient is lying down. As soon as the bleeding has stopped and dark crusts have formed, cooling compresses should be applied to the leech bites. We have found curd or lemon wraps to be effective for this purpose; these supportive measures enhance the results of treatment and reduce and/or eliminate the itching and swelling that often occur following treatment. The patient should keep the leg elevated during the first two days after treatment. The leech therapist should specifically advise the patient never to scratch on or around the leech bites since this could cause inflammation and permanent depigmentation of the bite marks.

The “dosage” guidelines provided below should be interpreted as reference values that must be adjusted to the individual needs of each pa tient. Based on our experience in practice, we also recommend that leeching should not be performed on patients with venous diseases on hot days unless absolutely necessary.

Acute Phlebitis, Acute Superficial Thrombosis

Six to ten closely spaced leeches are applied perivenously. Leeching should be performed two to three times within a period of approximately one week until the symptoms have subsided completely. Blood counts should be obtained before any repeat treatments are administered.

Postthrombotic Syndrome Secondary to Deep Leg Vein Thrombosis

Leeches can be applied to the affected region for superficial adjuvant therapy (only after completion of pharmacological anticoagulant therapy!). Repeat treatments can be considered if the initial treatment resulted in good improvement of symptoms and prolonged therapeutic effects. To avoid problems with wound healing, leeches should never be applied directly to regions with marked signs of dermatitis or ulceration.

The symptoms of CVI (e.g., feeling of heaviness, pain, swelling, and itching in the legs) typically occur after orthostatic stress. The severity of symptoms, not the cosmetic appearance, determines the need for treatment.

Four to six leeches are evenly distributed lateral to the affected veins. The treatment should be repeated at four- to six-week intervals, i.e., after the therapeutic effect subsides. In the case of severe varicosis in the thigh and calf regions, it may be necessary to apply more leeches (10–12) around the vein in order to cover the symptomatic region adequately. Blood counts should be obtained prior to bilateral or repeat leech applications.

Special recommendations apply when treating venous ulcers in the calf and forefoot region associated with severe CVI. We advise against applying leeches directly to the ulcers, even though good results have reportedly been achieved with this practice in isolated cases. Instead, we recommend that a few leeches be applied to the healthy skin roughly 2–10 cm proximal and lateral to the edges of the ulcer wounds.

Spider-Burst Veins

The number of leeches used depends on the extent of venous dilatation. As a rule, no more than four to five leeches are required for a focal area of spider-burst veins. The leeches can be applied directly in and around the spider-burst region.