Catheter Ultrasound for Cross-sectional Imaging and Drug Delivery to Vessel Wall

摘要

Current methods for delivery of an anti-restenosis drug to an arterial vessel wall post-percutaneous transluminal angioplasty and stent placement are limited in terms of drug choice, dosing level, and ability to assure drug coverage between the struts of a drug eluting stent. Intravascular ultrasound (IVUS) provides real-time, radiation-free, imaging and assessment of atherosclerotic disease in terms of anatomical, functional and molecular information. In this presentation, the design of a dual imaging / therapy IVUS catheter is described and results documenting gene and drug delivery reported. Microbubbles and drug / gene (shell associated or co-injected) are dispensed from the catheter tip. Using this approach, it becomes possible to address the need for complete vessel wall coverage and achieve delivery in regions poorly addressed using conventional stent-based approaches. A range of in vitro, ex vivo and in vivo results are presented. Our most recent results involve a demonstration in a pig model of coronary balloon angioplasty that produced a 33% reduction in neointima formation versus a drug plus microbubble, but no ultrasound, control.