<title>Comparative spectrum analysis of vascular wall of brachiocephalic arteries in norm and atherosclerosis</title>

Abstract

Since the late 1960s atherosclerotic plaque (AP) laser ablation techniques have been developed. Clinical data obtained with CW laser vaporization AP shows significant impairment of tissues close to plaque with following severe complications in postoperation period. The use of excimer pulsed laser decreases the harmful effects of laser radiation. However, data on spectrum of energy absorption by molecular AP structures are required for selective photodynamic action of UV laser emission. The aim of the present study is to estimate IR and UV absorption and fluorescence spectrum of intact and atherosclerosis-induced changes in aorta and brachiocephalic trunk. Autopsied vessel specimens with artery decease were analyzed. Absorption spectrum of frozen vessel slices (15 micrometers ) and oil emulsion was recorded. Characteristic absorption bands in 3000 cm-1 were noted as for AP as for intact tissue. In 1700 cm-1 AP IR spectrum has an absorption band which is not seen in normal tissue spectrum. Reflection spectrum of intact vessel wall surface and AP at range 45000 to 11000 cm-1 was recorded as well. In 32000 cm-1 reflection was 66% and 43% for AP and intact tissue, respectively. At range 17000 to 13000 cmMIN1 curve position is changed: reflection for AP-66%, for intact wall-93%. Thus, reflection, absorption and fluorescence spectrum of intact and atherosclerotic vessels vary significantly. It provides us with a basis for intravessel examination and selection of laser parameters for harmless endovascular surgery.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.