Clinical safety of magnetic resonance imaging in patients with implanted SynchroMed EL infusion pumps

Introduction: Patients with implanted SynchroMed spinal infusion pumps (Medtronic, Inc., Minneapolis, MN) routinely undergo magnetic resonance imaging at our institution. In August 2008, Medtronic issued an urgent medical device correction report regarding several pumps. Because of the rare potential "for a delay in the return of proper drug infusion" and "for a delay in the logging of motor stall events," "a patient's pump must be interrogated after MRI exposure in order to confirm proper pump functionality." This is particularly important in patients receiving intrathecal baclofen, for whom a delay in return of proper pump infusion could lead to life-threatening baclofen withdrawal syndrome. The objective of this report is to present our experience and protocol of performing magnetic resonance imaging in patients with implanted SynchroMed EL pumps. Methods: We retrospectively reviewed records of 86 patients with implanted SynchroMed EL spinal infusion pumps who underwent 112 examinations on 1.5-T magnetic resonance imaging scanners from September 1, 1998 to July 7, 2004. Results: No SynchroMed EL pumps were damaged by magnetic resonance imaging, and the programmable settings remained unchanged in all patients. Conclusions: Our data suggest that SynchroMed EL pump malfunction is indeed rare after routine clinical 1.5-T magnetic resonance imaging examinations. However, based on the Medtronic correction report, we perform pump interrogation before and after imaging.