The effect of contact Nd:YAG laser on arterial wall and atherosclerotic plaques. Considerations for angioplasty. An experimental study.

: The predictability and reproducibility of the laser effect in regard to depth of penetration and atheroablation are important considerations for clinical laser angioplasty. This study was designed to investigate those effects experimentally. A continuous wave contact laser system (SLT CL60R with an SLT MTR 1.5 sapphire tip) was used to produce a total of 592 lesions on 14 portions of atherosclerotic human aorta and 46 portions of intact pig aorta. Different power (1 to 40W) and time (0.1 to 10 sec.) were used. These tissue specimens were analyzed by an independent pathologist. Penetration and extent of thermal damage were recorded. The measurements were analyzed statistically. Analysis shows that the effect of the laser is reasonably well predictable horizontally (correlations .755 and .699) but not at all in depth (correlation .006).