The Mechanical Leech
By Kerrie Pinnock
ELE482 Biomedical Seminar III Monday April 29, 2002
Leeches have been used to treat many
different ailments from headaches to
stomach aches in ancient Egypt. Napoleon’s
military surgeon, Francois-Joseph-Victor
Broussais who was such a firm believer in
the medical benefits of leeches that in 1833;
he had more than 40 million imported into
France. In today’s medical field leeches are
used mostly to treat venous congestion.
Venous congestion is a post-surgical
complication that can occur after
reconstructive surgery. Venous congestion
is a complication that can happen after head,
neck, or breast reconstruction, limb or digit
reattachment, or other complicated
procedures where tissue is moved from one
place to another. Leeches increase the
blood flow to compromised tissue.
Complications happen as the arteries pump
blood into the reconstructed tissue, but the
associated veins do not let the blood flow
out, usually because the veins have become
clotted. The excess blood in the tissue, if
severe enough, can deprive the tissue of
oxygen and other nutrients and can cause it
to die.
In cases of venous congestion where
reestablishing the flow of blood is essential,
leeches have great therapeutic value
because, as they consume their meal of
blood, they promote blood flow through the
tissue. Even after a leech detaches from the
body, the anticoagulants it secreted into the
tissue allow the wound to ooze blood for
hours afterward. This oozing promoted by
the leech's natural anticoagulants also allows
blood to continue flowing through the tissue.
The mechanical leech was developed at
UW-Madison. The way it works is:
1.Tube delivers a solution containing
Heparin, an anticoagulant, to the wound.
2. Miniature bellows move the tube up and
down, preventing blood from clotting at the
bottom.
3. Actuator-driven disk rotates tube, also to
prevent clotting.
4. Holes in the cone release the solution to
cleanse wound.
5. Suction draws blood and solution out to
promote circulation
This mechanical leech has many advantages
for example it can penetrate a deeper level
under the skin, tapping into larger blood
vessels and treat a larger area of tissue.
Leeches are not sterile and can cause
bacterial infections. Nurses and pharmacists
tend not to like working with leeches
because they can sometimes slip off patients
and reattach themselves to other parts of the
body not in need of therapy. Most patients'
don’t enjoy having leeches attached to their
bodies. The mechanical leech will be able to
reduce this psychological stress.
The mechanical leech has only been tested
on pigs’ skin. Michael Conforti and Nadine
Connor are currently working toward a
mechanical leech that is smaller and easier
to use. Within the next three years this
product should be ready for human patients.
http://www.popsci.com/popsci/medicine/article/0,125
43,230229,00.html
http://www.otoweb.org/news_folder/mech_leech/mec
h_leech_B.htm
http://www.virginia.edu/topnews/releases2000/cottler
leech-dec-14-2000.html
http://www.news.wisc.edu/newsphotos/leech.html
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