FDA Public Health Notification:
Diathermy Interactions with Implanted Leads and Implanted Systems with
(You are encouraged to copy and
distribute this Advisory)
December 19, 2002
This is to alert you to the risk of
serious injury or death if patients with implanted electrical leads are
exposed to diathermy treatments.
FDA has received reports in which
patients with implanted deep brain stimulators (DBS) died after receiving
diathermy therapy. One patient received diathermy following oral surgery, the other for
treatment of chronic scoliosis. In both cases, the interaction of the
diathermy with the implanted device caused
severe brain damage in the area where the lead electrodes were implanted.
Types of diathermy affected
There are three types of diathermy
equipment used by physicians, dentists, physical therapists, chiropractors,
sports therapists, and others: radio frequency
(shortwave) diathermy, microwave diathermy and ultrasound diathermy. Shortwave
and microwave diathermy, in both heating and non-heating modes, can result in serious injury or death to
patients with implanted devices with leads. This kind of interaction is not
expected with ultrasound diathermy.
Electrocautery devices are not included in this notification.
Medical devices affected
Laboratory testing has shown that
patients with any implanted metallic lead are at risk of serious injury
when exposed to shortwave or microwave diathermy therapy. This
is true even if the implanted device is not turned on, and even if the lead is
no longer connected to an implanted system.
Interaction of the diathermy energy with the implanted lead causes excessive
heating in the tissue surrounding the lead electrodes. Insufficient testing has been done to determine whether there is a
safe distance between the diathermy applicator and the implant system that
might allow patients to be
treated with diathermy without risk of injury.
Shortwave or microwave diathermy
SHOULD NOT BE USED on patients who have ANY implanted metallic lead, or any
implanted system that may
contain a lead. Both the heating and
non-heating modes of operation pose a risk of tissue destruction.
If you are a physician who
implants or monitors patients with
leads or implanted systems with leads:
Explain to the patient what diathermy
is, and stress that they should NOT receive shortwave or microwave diathermy
If you are a health care
professional who uses diathermy
(shortwave or microwave) in your practice:
Be sure to ask the patient about
possible implants before deciding to
administer shortwave or microwave diathermy therapy. If the patient has an implanted lead or an implant containing a lead,
diathermy therapy should not be used, even
if the implant has been turned off.
Examples of implanted systems that
may contain a lead include cardiac pacemakers and defibrillators, cochlear
implants, bone growth stimulators, deep brain stimulators, spinal cord stimulators, and other nerve
Do not administer shortwave or
microwave diathermy therapy to a patient who has had an implant in the past unless you are absolutely
certainthat the implant and all leads in their entirety have
been removed. Note that leads are often left implanted after the implant is
Reporting adverse events to
The Safe Medical Devices Act of 1990
(SMDA) requires hospitals and other user facilities to report deaths and
serious injuries associated with the use of medical devices. This means that if a patient death or
serious injury can possibly be attributable to a diathermy device, or
attributable to interactions of diathermy
devices with any implanted device, you should follow the procedures
established by your facility for mandatory reporting.
If you have experienced problems with
diathermy devices, or adverse events involving interactions of diathermy
devices with any implanted device, you can report this directly to the manufacturer.
Alternatively, you can report directly to MedWatch, the FDA’s voluntary
reporting program. You may submit reports
to MedWatch four ways: online to http://www.accessdata.fda.gov/scripts/medwatch/; by telephone at 1-800-FDA-1088; by FAX at 1-800-FDA-0178; or by mail to MedWatch, Food and Drug
Administration, HF-2, 5600 Fishers Lane, Rockville, MD 20857.
Getting more information
If you have questions regarding this
letter, please contact Marian Kroen, Office of Surveillance and Biometrics
(HFZ-510), 1350 Piccard Drive, Rockville, Maryland, 20850, by fax at 240-276-3356, or by e-mail at
email@example.com. Additionally, a voice mail message may be left at
240-276-3357 and your call
will be returned as soon as possible.