Overview Of Angioplasty: Need For Imaging And Sensing (English)

Balloon angioplasty is a well established non-surgical treatment of ischemic vascular disease. Balloon dilatation increases the lumen in a stenosed artery by overstretching the wall and fracturing the atherosclerotic plaque. Fluoroscopy is adequate to guide the proper placement of guide wire and balloon catheter. Fluoroscopy largely fails, however, when a different recanalization strategy is choosen to address the major problems associated with balloon dilatation. In the past few years, more than twenty different recanalization catheters have been developed that physically remove obstructing plaque. In the femoral artery, both mechanical and thermal methods appear to be quite successful in traversing total occlusions in spite of 'blind' guidance by fluoroscopy. However, subsequent balloon dilatation is often needed. The femoral artery is large and runs a fairly straight course. Perforation of the femoral artery is a minor complication. In the coronary arteries, in contrast, the novel angioplasty methods have met with variable success. These arteries are small, tortuous and move continuously. The anatomy and composition of the plaque is complex and the remainder of the diseased wall may be thin. In the coronary arteries, the margin between recanalization and perforation is small. The latter is a potentially fatal complication. Thus, there is a great need for a catheter that is capable of high resolution imaging and tissue identification in obstructed arteries of small caliber. Intra-arterial echo imaging, possibly combined with laser fluorescence spectroscopy, seems a promising approach. The design of a catheter that combines these powerful diagnostic features with steerability, flexibility and controlled ablation is now the major engineering challenge in interventional cardiology.