Effects of 193 nm. and 248 nm. Excimer Laser on Inorganic Calcific Mineral Portion of Human Atherosclerotic Plaque

Abstract

Atherosclerosis (ASO) that is severe enough to cause symptoms almost always contains significant amounts of inorganic mineral salts of calcium within the organic lipoprotein plaque. Many recent reports have focused on the soft organic part. (1) We have chosen to concentrate on the rock-like inorganic portion, since for laser angioplasty to be successful this solid material will have to be removed safely. Pieces of this rock-like material were dissected out from human arteries obtained at autopsy and studied by scanning electron microscopy (SEM), energy dispersive analysis, x-ray diffraction (XRD) and infrared spectroscopy.(2) This inorganic mineral component was identified by XRD to be calcium hydroxide orthophosphate , CA5 (PO4) 3OH. As this material was heated to approximately 1,200°C it was observed to become more crystalline. © 1985 Optical Society of America