Leeches used to reattach the outer ear: When the outer ear is avulsed during a traumatic accident, it must be reattached as a “free” graft. At first there is no blood supply. The arteries attach first, after 24 hours, but the blood cannot get out of the graft. The graft will fill with blood and die unless it is drained. Leeches not only drain the blood, but also secrete an anticoagulant which will aid in continued blood drainage.
