 |
Department of Medical Entomology |  |
| Maggot Debridement Therapy (MDT) |
Maggots will always
have an image problem. But the humble maggot, which is the immature stage of
a fly, may have a lot to offer the field of medicine in the 21st century. Maggot
debridement therapy (MDT) is an old remedy that has been revised and proven
to be invaluable in cleansing non-healing wounds. This simple procedure involves
the placement, using restrictive dressings, of live disinfected maggots into
non-healing wounds to provide for cleansing of necrotic tissue and initiation
of the healing process.
The
History of MDT
For centuries, maggots
were known to have beneficial effects on wounds. Ambroise Paré is credited
to be the first to note his observations in 1500's. Throughout military history
many other positive comments have been recorded in regard to maggot infested
wounds by military surgeons that attended wounded soldiers. However, it wasn't
until the 1920's that therapeutic experimentation with maggots was instigated
by William Baer, a clinical professor in orthopaedic surgery at the Johns Hopkins
University in Baltimore, Maryland, whose unorthodox methods were successful
in the treatment of osteomyelitis and pyogenic wounds. His methodology of MDT
was adopted and routinely used in over 300 hospitals in the USA throughout the
1930's and early 1940's. Thereafter, with the introduction of penicillin and
other modern surgical procedures, MDT was replaced in the late 1940's.
The 1980's brought an increase of
bacterial resistance to antibiotics, and MDT was revisited as a procedure to
assist in the treatment of non-healing wounds that were recalcitrant to antibiotics
and when surgical intervention was not an option. Dr Ronald Sherman, and associates
from the Veterans Affairs Medical Centre, California, pioneered the reintroduction
of MDT. His clinical trials indicated that MDT was several times more efficient
at debriding infected and gangrenous wounds (and healing them more rapidly)
when compared with other modern non-surgical treatments. In the last 15 years,
thousands of patients with bedsores, leg ulcers, diabetic foot wounds and post
surgical infections have been successfully treated by MDT. At present, health
care facilities in the UK, Europe and the USA now produce thousands of medicinal
maggots per week for therapists. In the UK alone, MDT has been estimated at
saving the national health system over one billion dollars annually, and is
now recognised as a procedure that can be officially prescribed and claimed
on health care benefits.
Mystery still surrounds the unique
way that maggots 'nurse' wounds as they actively consume dead tissue and fluids.
As they cleanse the wound site the maggots exude an antibacterial agent that
has a wide spectrum of activity against many resistant pathogens. They also
possess diverse proteolytic enzymes, which are capable of digesting bacteria.
The mechanical feeding of the maggots and the reduction of necrotic tissue changes
the wound's environment from an acid to a more alkaline pH, which assists in
stimulating healthy granulated tissue.
How to obtain MDT in Australia
Persistent requests for sterile maggots from throughout Australia encouraged the Department of Medical Entomology at ICPMR to maintain a colony of the blow fly Lucilia sericata (the species most widely used for MDT) and establish a procedure for surface sterilisation of the maggots. Based on Ronald Sherman's methodology we now supply (with cost recovery) disinfected maggots on request for local, interstate and overseas patients.
Contact details for the supply of MDT:
Department of Medical Entomology,
ICPMR
Westmead Hospital
WESTMEAD NSW 2145
Ph: 02 9845 7265
Fax: 02 9893 8659
Note that maggots can be delivered
anywhere, although a service charge will be added. Please contact the Department
for pricing details.
Although not all patients are suited
to this therapy, MDT is an efficient, low cost alternative method to cleanse
and promote the healing of chronic soft tissue wounds before they progress to
a stage where amputation is the only alternative. Although acceptance of MDT
is not yet widespread in Australia, perhaps a new image of maggots is slowly
emerging wherein they are an effective and economic means of treating wounds
and saving limbs for patients in our health system!
R.A.Sherman, M.J.R.Hall, S.Thomas. Medicinal Maggots: An Ancient Remedy for some Contemporary Afflictions. Annual Review of Entomology, 2000, 45:55-81.
Church, J.C.T., Larva Therapy in Modern Wound Care : A Review. Primary Intention. May: 63-68. 1999.
L.M. Vistnes, M.S.RitaLee, G.A.Ksander, Proteolytic activity of blowfly larvae secretions in experimental burns. Surgery, Nov, 1981.
Sherman, R.A., Maggot Debridement in Modern Medicine. Infections in Medicine. Sept: 651-656. 1998.
Teich, S., & Myers, R.A.M., Maggot
Therapy for Severe Skin Infections. Southern Medical Journal. Vol. 79, No. 9,
1153-1155, 1986.
Web
Links
http://www.ucihs.uci.edu/com/pathology/sherman/home_pg.htm
(Ronald Sherman's MDT web site)
http://www.smtl.co.uk/
(LarvE Biosurgical Research Unit, Wales)
Produced 3/Jun/2004
