Developing Next-Generation Medical Devices
A New Generation of Implantable Cardioverter-Defibrillators
MUSC Health cardiologist Michael R. Gold, M.D., Ph.D., has played a seminal role in introducing innovations in implantable cardioverter-defibrillator (ICD) technology into the clinic. Gold led the trials resulting in FDA approval of the first MRI-compatible ICD and the first entirely subcutaneous ICD (S-ICD), serving as worldwide principal investigator for the former and U.S. principal investigator for the latter.
Until this year, MRI had been contraindicated in patients with ICDs because the magnetic field could decrease the overall efficacy of the heart-pacing device or overheat the wires. In September, the FDA approved the Evera MRITM (Medtronic; Minneapolis, MN) as the first MRI-safe ICD on the basis of efficacy and safety results reported by Gold and colleagues in the June 23, 2015 issue of the Journal of the American College of Cardiology (JACC). When switched to “sleep mode,” the device can still monitor the patient’s heartbeat but is temporarily incapable of sending an electric shock to the heart. All 275 participants in the trial (NCT02117414) were implanted with the novel ICD; some then underwent full-body MRI. At 30-day follow-up, no loss in pacing or sensing ability was observed in devices exposed to MRI.
Gold also helped design—and MUSC Health participated in—early clinical studies that led to the 2012 approval of the subcutaneous ICD (S-ICD System®; Boston Scientific, Natick, MA), in which the leads are placed under the skin of the chest and are not connected to the heart or vasculature. The device’s clinical promise was confirmed in an article by Gold and colleagues in the April 28, 2015 issue of JACC, which reported good efficacy and a low complication rate at 22 months among 882 patients implanted with S-ICDs in previous clinical trials. Of the 111 events of ventricular fibrillation/tachyarrhythmia, 90 percent were terminated with one shock and 98 percent within five. The overall complication rate was 11.1 percent, with fewer complications seen as clinicians gained experience with the device.
Advancing Neuroscience Technologies
The MUSC Zucker Institute for Applied Neurosciences (ZIAN) is a technology accelerator that develops neuroscience technologies and moves them to commercialization. In 2015, ZIAN licensed its first medical device, Sinu-Lok™, a rod implant used in minimally invasive lumbar spinal fusion surgery. Spinal surgical device provider Amendia, Inc. (Marietta, GA) acquired the exclusive worldwide rights to manufacture and sell the device.
Sinu-Lok is an improvement over the standard rods surgeons have used in lumbar spinal fusion surgery. The standard bowed rod puts stress on the construct components, which can lead to a loosening of the construct after the surgery and other complications. Sinu-Lok has a sine wave (oscillating) shape that creates several concave locations in which the screws can seat when tightened. This patented shape also provides an extended range of axial connections between the screw-rod interface when the construct is tightened, creating divergence of the screw towers instead of the convergence caused by the standard rod.
Next in ZIAN’s pipeline is the Blink Reflexometer™, a device that detects mild traumatic brain injury (concussion). Currently, there is no commercially available device that provides an objective way to detect a potential concussion on the athletic field, leaving clinicians and trainers with only subjective measures of altered behavior or cognitive function. The handheld Blink Reflexometer uses stimuli to trigger a blink and a high-speed camera to collect data on the body’s response to these stimuli. The ZIAN research team collected baseline measurements from football players and other athletes in summer 2015 and tested the device throughout the fall season. It is expected to be commercially available by 2017. ZIAN has eight additional active projects in the areas of cranial access for deep brain procedures, spine surgery, intraoperative neuromonitoring, glioblastoma treatments, and general surgical instruments.