Infusion port dislodgment of bilateral breast tissue expanders after MRI

Tissue expanders are placed routinely for breast reconstruction, and magnetic resonance imaging (MRI) is a common diagnostic procedure. Many studies have reported on the safety of MRI in patients with nonferromagnetic implants; however, many tissue expanders contain ferromagnetic components. The authors 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 contain integral nonferromagnetic infusion ports, as well as small, powerful Magna-Site magnets. Several weeks postoperatively the patient underwent MRI of her spine, which was ordered by her primary physician for back pain. Subsequently, the infusion ports could not be located with the finder magnet. A chest radiograph was obtained, which demonstrated bilateral dislodgment of the infusion ports. Surgical removal and replacement of the tissue expanders were required. Safety considerations of MRI have been discussed extensively in the literature, and data on MRI with various implanted devices have been obtained. The potential risks of performing MRI on patients with metallic implants include conduction of electrical currents, heating of the implant, misinterpretation resulting from artifact, and the possibility of movement or dislodgment of the implant. The small magnet integral to many tissue expanders may be overlooked by patients and physicians during pre-MRI screening. All patients undergoing tissue expansion with implants that contain integral ports should be thoroughly warned about the potential hazards of MRI.