people today regard leeches as loathsome, but for centuries these
blood-sucking creatures were a mainstay of medical care. Derived from
the Anglo-Saxon word loece, to heal (Medieval doctors called themselves
leeches), the leech was used as an adjunct to bloodletting, in places
too sensitive or confined for the lancet or other blood-letting instruments.
Physicians applied leeches to areas such as "the gums, lips, nose,
fingers," or even "the mouth of the womb," according to a medical
text from 1634.
The common medicinal leech, Hirudo medicinals, produces natural anti-coagulants and anesthetics in its saliva, so patients bleed readily and generally feel nothing during the procedure. Traditionally used in a minority of cases, leeches became popular in the 19th century -- so much so that the species became endangered in Europe. In 1833 alone, French doctors imported 41,500,000 leeches. Eventually the procedure was largely abandoned, along with other forms of bloodletting.
Today leeches have found renewed utility in certain surgical procedures, particularly after microsurgery. Doctors sometimes find it helpful, for example, to use leeches to restore circulation to a re-attached finger, or to portions of the skin following plastic surgery.
-- Douglas Starr
Photo: Courtesy of the National Library of Medicine.