Hirudotherapy Leeches have been known for their medicinal properties since ancient times. At the Lausanne University Hospital, they are used in emergency transplants and reconstructive surgery.
These invertebrate animals from the phylum of ringed worms are coming back in vogue in both certain private medical practices and surgery services at university hospitals. “Leeches are mostly used in two ways,” says Dr Dominique Kähler Schweizer, an expert on leeches and co-founder of Hirumed, the only medicinal leech farm
in Switzerland. “In hospitals, leeches are primarily used for
their mechanical effect of draining blood in the event of congestion after reconstructive surgery.” Not only are they the best way to salvage a graft, leech saliva is also popular for its anti-inflammatory and anti-coagulant properties. “Its saliva contains more than a hundred active compounds, but only about thirty are really well-known today,” she says. “In private doctors’ offices, they are mainly used for their success in treating tendinitis, arthritis and boils, as well as some forms of back pain.”
The company Hirumed, set up in Wil in the canton of St. Gallen, has the only leech farm in the country. “Leech eggs develop inside cocoons during six weeks. It takes nearly two years on average from the time leeches hatch until they can be used for medicinal purposes,” says Dominique Kähler Schweizer, who founded the company with her husband in 2002.
The Lausanne University Hospital orders medicinal leeches from Hirumed on a regular basis. They are shipped by lorry and placed in an aquarium in the main hospital pharmacy as soon as they arrive. When a doctor decides to use a leech in treating a patient, a prescription is sent to the hospital pharmacy. Five or six leeches are placed in a jar and sent to the nurse from the service that placed the order.
The leech is removed from the jar using sterilised forceps. The first challenge is to distinguish the animal’s head from its tail so that the mouth is placed on the area to be treated. Leeches can survive without eating for several months. They are actually starved to promote blood absorption during treatment. Once the leech is in place, its suction drains excess blood from the congested area. Leech saliva contains hirudin, which also thins the blood. The nurse monitors the leech regularly. Its meal takes about thirty minutes, after which the animal should immediately be removed from the patient’s wound. Leeches often regurgitate some of the blood they ingest, increasing the risk of infection.
After treatment, the nurse places the leech in a jar with a powerful disinfectant to euthanise it. The airtight container is disposed of in a bin used for special waste before being incinerated by the city of Lausanne.