A recent warning letter has advised clinicians to avoid implanting a magnetic-port breast tissue expander in patients with a cardiac pacemaker or implantable cardioverter-defibrillator (ICD).
The letter explained that some breast tissue expanders—used after mastectomy to make room for a breast implant as well as to treat underdeveloped breasts or other soft tissue deformities—have a magnetic injection port to guide surgeons when they inject saline fluid to expand the device. In patients who have arrhythmia treated with a pacemaker or ICD, the magnetic port of a breast tissue expander can come close enough to cause magnetic interference (http://1.usa.gov/1M9YzVG).
Voelker R. Avoiding Magnetic Interference. JAMA. 2016;315(15):1555. doi:10.1001/jama.2016.3572