Sucking your thumb might be the best way to save it -- at least when the sucking is done by leeches. The three-jawed freshwater parasites, approved last week as medical devices by the Food and Drug Administration (FDA), can be indispensable tools when reattaching a thumb, a nose, a finger or toe, says University of Missouri Health Care plastic surgeon Matthew Concannon. When blood won't flow out of a newly reattached part -- a rare complication, says Concannon -- a leech's sucking can help get the blood moving while an anticoagulant in the worm's saliva facilitates the process.

While leeches have long been used in U.S. hospitals, French leech seller Ricarimpex was the first company to seek and win FDA marketing approval under the agency's 1976 law governing medical devices. Leech suppliers in business before that time were grandfathered in.

These days, the post-surgical use of leeches represents a last-ditch effort. "At a point when we've thrown everything at [patients]," Concannon said, he brings in the leeches. After an hour, the first leech is full of blood, and another takes its place. Leech swaps continue until blood flows normally again. That can take days, even weeks.

Nice work? "It's just part of the training," Concannon says, "[and] the indications for leeches are very narrow."

-- Matt McMillen