AccuGyd: Accurate Guidance for MRI-Guided Minimally Invasive Neurosurgery

Abstract: The benefits of Minimal Invasive Surgery (MIS) extend to more applications and procedures every year, as surgeons see the benefits of smaller openings, faster procedure times, less infection, fewer complications, and faster recovery times. MIS procedures in the brain have been slow to gain acceptance, due to the need to verify accurate device placement prior to making irreversible changes to the brain. Current devices for guiding catheter procedures require complicated iterative manipulation, large holes in the skull for brain access, and long procedure times. These factors make intraoperative MRI less attractive. However, numerous therapies are ripe for improvement, such as administration of drugs and biologics, placement of electrodes for therapy (deep brain stimulation and epilepsy) or monitoring (epilepsy), ablation of epileptic foci, and evacuation of intracerebral hemorrhages. Intraoperative magnetic resonance imaging (MRI) can assist neurosurgeons in placing devices accurately and with increased confidence, using less invasive methods than possible in the traditional operating room. Considering Parkinson’s Disease (PD) alone, new therapies are under development which could benefit all of the 60,000 new PD patients each year, opening up a new market for MRI-guided MIS. We propose a novel device, “AccuGyd”, a highly accurate and precise drill and catheter guide, that is rapid and easy to install and utilize. It may be affixed either to the skull or a stereotaxic frame. A single MRI scan will yield information to calculate the trajectory between AccuGyd and the tissue target. Major advantages of the AccuGyd technology for MIS include: 1) it utilizes much smaller holes in the skull for brain access and device placement; 2) it is extremely reproducible and mechanically stable; and 3) it substantially reduces the time for an MRI guided procedure. This Phase I project will focus on tasks needed to incorporate AccuGyd into a comprehensive MRI Guidance platform that can be be used in a larger Phase II study. The Phase I tasks include further development of the device itself, prototype fabrication, development and implementation of an algorithm to define the optimal trajectory of the AccuGyd based on MRI image features, and validation of accuracy and precision using a realistic head-shaped phantom and human head cadavers. The result will be a validated AccuGyd prototype that is ready to enter the FDA 510(k) clearance process.Project Narrative: Minimally invasive surgical methods are desired in all areas of medicine, but particularly in brain surgery, yielding significant reductions of surgical time, complications, recovery time, and the disruption of otherwise normal tissue. Magnetic resonance imaging (MRI) can guide devices to precisely targeted locations within the brain and then deliver electrical stimulation, heat, or drugs, but the process of accessing the brain and then orienting a catheter or other device to a specific target location takes on the order of 2 hours per hole. This proposal aims to build a MRI-compatible drill guide that will allow surgeons to drill a minimal hole and orient the inserted device through the hole and to its target within 1 millimeter in 30 minutes; the reduced complexity of the surgery will allow more neurosurgeons to use MRI guidance for advanced therapy procedures.