Document Type

Article

Rights

This item is available under a Creative Commons License for non-commercial use only

Disciplines

Medical engineering

Publication Details

Critical Reviews in Biomedical Engineering

Abstract

Certain minimally invasive cardiology procedures, such as balloon angioplasty and stent implantation, critically require that the site of an arterial blockage be crossed by an intraluminal guidewire. Plaques resulting in near or totally occluded arteries are known as chronic total occlusions (CTOs), and crossing them with conventional guidewires is a significant challenge. Among the most promising proposed solutions is the delivery of high power, low frequency ultrasonic vibrations to the occlusion site via an intraluminal wire waveguide. The vibrating distal-tip of the ultrasound wire waveguide is used to transmit energy to the surrounding plaques, tissues and fluids in order to ablate or weaken atherosclerotic plaque. Potential mechanisms of interaction with the plaque and adjacent fluids identified in the literature include; (i) direct contact with the waveguide distal tip, (ii) subcavitational acoustic fluid pressure fluctuations, (iii) cavitation, and (iv) acoustic streaming. This article will summarize developments in this area over more than two decades, describing experimental methods for device performance characterization, preclinical tests, early clinical investigations and, later, full clinical trials. The article will also review theoretical foundations, and numerical models suitable for device design and analysis. Finally, important issues for future research and for the development of this technology will be considered.