A novel approach to delivering an SMP device using a Joule-heating catheter for the treatment of fusiform aneurysms

Cerebral fusiform aneurysms are characterized by the circumferential dilation of an arterial wall and exhibit weakened wall strength, making the aneurysms prone to rupture and hemorrhage. There are currently no viable clinical treatments for fusiform aneurysms. Current studies point to the utilization of a polyurethane-based shape memory polymer (SMP) device, which in clinical application would incorporate an expanding SMP stent coated with expanding foam for the occlusion of the non-necked aneurysms. The objective of this project is to develop a thermally conductive housing to ensure safe deployment and actuation of the SMP device via an intravenous, Joule-heating guide catheter. The catheter will deliver the SMP device to the site of the aneurysm while in its secondary, compressed conformation. Upon arrival, Joule heating of the SMP device will raise its temperature above the specified glass transition temperature (T_g), causing expansion and occlusion. The first prototype of the device will consist of a 3-D printed plastic stent coated in SMP foam. A specially designed testing apparatus will quantify results by mimicking the physiological conditions of the middle cerebral artery (MCA) and brain tissue with respect to temperature and pressure. Prototype testing will include ensuring proper placement of stent and deviation from this location, successful actuation, and percent aneurysm occlusion by the foam.