SYSTEMS AND METHODS FOR TREATING VASCULAR OCCLUSIONS WITH CATHETER BASED ULTRASOUND

摘要

A system and method is provided for generating ultrasound at the tip of anintravascular catheter. This may be used for the treatment of vascularocclusions,including chronic total occlusions (CT0s) and thrombotic occlusions (e.g.,deep veinthrombosis, stroke, myocardial infarction). For instance, the systems andmethods maybe used to induce cavitation to enhance the enzymatic degradation of avascularocclusion. In some configurations, the approach employs a hollow cylindricaltransducer,electrically stimulated in the radial direction at a frequency correspondingto the lengthmode excitation, thereby projecting ultrasound forwards past the catheter tip.Thisdesign overcomes electrical impedance issues for the generation of lowfrequencies witha smaller diameter transducer capable of negotiating a coronary artery. Thehole withinthe transducer may accommodate a guidewire to facilitate its placementadjacent to theproximal portion of the occlusion.