Breast Tissue Expanders Used Near Internal Defibrillators May Cause Magnetic Interference: FDA

Federal regulators indicate that patients with breast tissue expanders may face a risk of problems with pacemakers and defibrillators, which may fail due to magnetic interference. 

The FDA issued a warning to healthcare providers on March 8, including breast surgeons, cardiac electrophysiologists, cardiologists and plastic surgeons.

The ageny indicates that there is the potential for interference between breast tissue expanders with magnetic ports and implantable cardioverter-defibrillators (ICD) or pacemakers. The metal ports used in many breast tissue expanders have the potential to cause ICDs and pacemakers to malfunction, potentially causing serious injury to patients.

In some cases, patients with both the breast expander and a cardiac device may have a magnetic port that can come close enough to the cardiac device to cause magnetic interference.

If magnetic interference is caused, the device will enter “magnet mode”. In this instance, an ICD will not deliver life-saving shocks or anti-tachycardia pacing therapy, which may be life threatening to the patient if dangerous abnormal heart rhythms were to occur.

The warning comes after reports of magnetic interference between breast tissue expanders with magnetic injection ports and either ICDs or pacemakers in patients. The FDA then analyzed peer-reviewed literature, device labeling, adverse event medical device reports, and information from ICD manufacturers, health care organizations, and professional societies.

The FDA is calling this a ‘small population risk,” since it is uncommon for patients with ICD or pacemakers to have also have breast reconstruction. However, for this who may be impacted, it is a potentially serious risk.

ICDs are an implantable device used to correct-life threatening heart rhythm abnormalities in patients at risk for sudden cardiac death, or death from heart attack. Pacemakers are small devices placed in the chest or abdomen to help regulate abnormal heart rhythms.

Breast tissue expanders are temporarily used to prepare patients for reconstructive breast surgery after mastectomy and also used to treat under-developed breasts or other soft-tissue deformities. Expanders are used for no more than 6 months to prepare the patient for surgery. Some expanders have a magnetic injection port used to guide the surgeon when injecting saline fluid to expand the breast.

Inconsistent Device Warnings

Patients who experience interference problems may hear an electronic tone indicating that the cardiac device has entered magnet mode, but this does not occur in every instance. When the device enters magnet mode, the device continuously paces without sensing the patient’s own heart rhythm. This can result in irregular heartbeats or more serious injury to the patient.

The FDA indicated that the likelihood of either serious event occurring varies depending on the type of cardiac implant and proximity of the expander to the device.

Both cardiac devices have labeling warning of potential magnetic interference and the breast expanders label warns of patients who already have implanted devices.

In some cases, the ICD can be reprogrammed if a patient has a breast tissue expander in place, to help reduce interference. An alternative expander can be used in patients with implanted cardiac devices, including breast tissue expanders with a non-magnetic port, a non-magnetic metal disc or remote port.

The FDA recommends healthcare providers avoid implanting a magnetic-port breast tissue expander when possible in patients with cardiac devices and reviewing all device labels for any implantable devices, including reviewing available treatment options before deciding on a course of action.

If a patient with an implanted magnetic breast tissue expander requires the placement of an ICD or pacemaker, the FDA advises careful consideration of the choice of cardiac device, location and timing should be reviewed with the patient. Another possibility to help prevent interference would be to conduct more frequent cardiac device checks.