Microfabricated device for arterial wall and atherosclerotic plaque penetration

Percutaneous coronary intervention is currently used to treat coronary atherosclerosis but is plagued by restenosis. The atherosclerotic plaque acts as a barrier, preventing the delivery of drugs or gene therapy to prevent restenosis. We hypothesize that microfabricated probes, manufactured using silicon fabrication technology, can penetrate through atherosclerotic plaque, creating paths for therapeutic delivery. Two sets of microfabricated probes (65 ± 15 and 140 ± 20 μm) were deployed in normal and atherosclerotic rabbit iliac artery segments (n=5 each) under distention pressures of 100, 200, 300, and 500 mmHg, to simulate deployed stents. The tissues were fixed while the probes remained in place and analyzed using standard SEM, TEM and light microscopy techniques to evaluate the extent and nature of vessel penetration. In healthy tissue, microprobes are able to pierce the internal elastic lamina and penetrate the media, with the highest probes nearly reaching the media/adventitia boundary. Atherosclerotic plaque is pierced by microprobes at all intraluminal pressures examined. These results indicate that microprobes may serve as a technique to penetrate the atherosclerotic plaque for the purpose of delivering therapeutics beyond the plaque.