Infusion port dislodgment of bilateral breast tissue expanders after MRI

Tissue expanders are placed routinely for breast reconstruction, and magnet ic resonance imaging (MRI) is a common diagnostic procedure. Many studies h ave reported on the safety of MRI in patients with nonferromagnetic implant s; however, many tissue expanders contain ferromagnetic components. The aut hors present a case of bilateral tissue expander infusion port dislodgment after MRI. A 56-year-old woman underwent bilateral mastectomy and immediate reconstruction with McGhan BIOSPAN tissue expanders. These implants contai n integral nonferromagnetic infusion ports, as well as small, powerful Magn a-Site magnets. Several weeks postoperatively the patient underwent MRI of her spine, which was ordered by her primary physician for back pain. Subseq uently, the infusion ports could not be located with the finder magnet. A c hest radiograph was obtained, which demonstrated bilateral dislodgment of t he infusion ports. Surgical removal and replacement of the tissue expanders were required. Safety considerations of MRI have been discussed extensivel y in the literature, and data on MRI with various implanted devices have be en obtained. The potential risks of performing MRI on patients with metalli c implants include conduction of electrical currents, heating of the implan t, misinterpretation resulting from artifact, and the possibility of moveme nt or dislodgment of the implant. The small magnet integral to many tissue expanders may be overlooked by patients and physicians during pre-MRI scree ning. All patients undergoing tissue expansion with implants that contain i ntegral ports should be thoroughly warned about the potential hazards of MR I.