Atherosclerotic tissue analysis by time-resolved XeCl excimer laser reflectometry

Area of Science:

• Biomedical Optics
• Laser-Tissue Interaction
• Cardiovascular Research

Background:

• Atherosclerosis poses significant health risks, necessitating advanced diagnostic and therapeutic approaches.
• Laser angioplasty is a promising technique for treating vascular diseases.
• Understanding laser-tissue interactions is crucial for optimizing angioplasty procedures.

Purpose of the Study:

• To investigate the temporal modifications of XeCl laser pulses reflected from human aorta tissue.
• To analyze the dynamic tissue reflectivity of normal and atherosclerotic aorta tissues.
• To determine the potential of reflected pulse analysis for identifying ablation targets in laser angioplasty.

Main Methods:

• XeCl laser pulses were directed at human aorta tissue samples (normal and atherosclerotic) immersed in saline.
• Incident pulse fluences were varied between 0.7 and 6.5 J/cm².
• Temporal changes in the reflected laser pulses were measured and analyzed.

Main Results:

• Significant changes in reflected pulse duration were observed at fluences of 2.6 J/cm² for normal tissue and 3.0 J/cm² for calcified plaque.
• Dynamic tissue reflectivity varied with incident fluence and tissue type.
• Threshold fluences for pulse modification were identified for different tissue conditions.

Conclusions:

• Reflected XeCl laser pulse analysis reveals distinct changes in temporal characteristics based on tissue type and incident fluence.
• This method shows potential for real-time tissue differentiation during laser angioplasty.
• The identified fluence thresholds may aid in precise targeting for laser ablation of atherosclerotic plaques.