They've been using leeches for years now. I remember when it was the Hot New Thing in the 1990s. See, they stop blood from clotting better than anything else we have, so they're good for preventing blood clots in small, localized areas.

They're also using maggots to eat away necrotized flesh from a wound. I have a way harder time witht that than I do with leeches. Bleah.

"Three Stories" is the best House.