It may sound like a lawyers' convention gone horribly awry, but soon blood-sucking leeches could be everywhere.

A French firm has won approval from the Food and Drug Administration to market leeches as a medical device. According to the law, a medical device is any article designed to diagnose, cure, treat, prevent, or mitigate a disease or condition. Leeches have been used by medical practitioners for thousands of years and are used now to help heal skin grafts and amputations. Ricarimpex SAS is the first company to request and receive the government's imprimatur to market them.

When it comes to medical devices, Tom Gardner has his ear to the ground and has picked a few such companies for the Motley Fool Stock Advisor, such as Kensey Nash (NASDAQ:KNSY) and Possis Medical (NASDAQ:POSS), to name two. Leechcraft, I am sure, is one medical device Tom never saw coming.

Medical leeches -- officially hirudo medicinalis -- have been used in American hospitals for many years. Doctors have long extolled the virtues of the aquatic animal that harried Humphrey Bogart in The African Queen. By attaching leeches to the area of a skin graft or an amputation, the flow of blood is restored in blocked veins by removing the blood that has pooled.

When a leech bites, the puncture wound bleeds for hours. The saliva of the leech contains substances that anesthetize the wound area, dilate the blood vessels to increase blood flow, and prevent the blood from clotting. They are particularly useful in attaching thin-walled veins that doctors have found to be difficult in suturing.

In 1976, a medical device law was passed that allowed companies already raising and selling leeches to continue doing so. Anyone else that wanted to had to first seek approval. Ricarimpex, which has been breeding leeches for 150 years, was the first company to seek permission under the law.

Before giving its stamp of approval, the FDA said, it reviewed the medical literature and safety data, as well as examined how the leeches were fed, their environment, and the employees who handled them. Goodness knows we wouldn't want just any old leech sucking our blood.

At least with official sanction of their care and well-being granted by the government, leeches can now give lawyers a run for their money.

Fool contributor Rich Duprey ascribes to the line about lawyers in Shakespeare's Henry VI. He does not own any of the stocks mentioned in this article.