Leeches in modern medicine?

Your doctor won't reach into a jar of slimy bloodsucking leeches when you complain of a stomach ache, but he may very well reach for a leech, for example, if he's trying to reattach a finger you severed while chopping wood.

It's true, unappetizing as it may seem. Leeches are still used in surgeries where increasing circulation and inhibiting clotting are critical, such as reconstructive surgery after breast cancer. Leeches have a natural anticoagulant in their saliva which increases blood flow through traumatized tissue, helping to keep it alive during lengthy surgeries. Leeches even come with a natural anesthetic and antibiotic to help break down clots and keep the blood flowing.

There is one drawback. Leeches can harbor dangerous bacteria which can be transmitted to the patient and cause infection. So doctors at the University of Wisconsin are developing a synthetic leech in the shape of a small glass and metal vial with fluid running through it, which mimics the leech's ability to irrigate the wound and increase circulation with a constant supply of fresh oxygenated blood while damaged veins regrow.

Resources

Read the British Broadcasting Corporation (BBC) article on medicinal leeches.
A 1998 article from Carolina Biological Supply called Leeches in Modern Medicine details some history and biological facts about leeches. (PDF file)