Mechanical and acoustic analysis in ultrasonic angioplasty

摘要

The goal of this study was to investigate the relationship between ultrasonic tissue ablation and passive mechanical elasticity. Experience with ultrasonic angioplasty in experimental settings (in-vivo and in-vitro) together with clinical experience in peripheral vascular disease is reported. A model composed exclusively of a hydroxyproline ballistic gelatin matrix showed a negative correlation between material elasticity and the rate of ultrasonic ablation. This model provided a means of studying the effects of collagen content on ablation, exclusive of other biologic components. Ballistic gelatin ablation (mg/sec) was found to increase logarithmically with decreasing protein concentration over the range studied (20.00 to 1.25%). Ablation as a function of gelatin elasticity behaved in a similar manner. Temperature of the material ablated was also demonstrated to affect the rate of ablation. We conclude that the previously reported differences in ablation between thrombi and blood vessel are predictable based on the large difference in their mechanical elasticity, and that this difference provides a wide margin of safety.