Recanalisation of Coronary Atherosclerotic Obstruction by Laser Radiation.

The potential use of lasers to vaporise atherosclerotic plaque obstructions is rapidly becoming recognised. The properties of laser light are unique in that it is coherent, monochromatic and collimated. It can be focused into tiny, flexible optical fibre made of silica which can be inserted into a blood vessel and passed intravascularly to an area of obstruction. The ease of plaque penetration is largely dependent upon the absorptive characteristics of the plaque's substances (i.e., lipid, hyaline or calcium), beam focus, power intensity and duration of laser exposure. Laser radiation of fibrous areas and especially calcified areas causes remnants of charred debris in the irradiated pathway, whereas no debris is found when exposure is focused over a primarily fatty plaque. The laser can also be utilised to canalise the organised thrombus. Since blood clots are comprised of red blood cells which contain haemoglobin pigments, the red clot is readily absorbed and thus vaporised by argon laser energies. Potential complications of recanalising coronary obstructions include perforation, aneurysm formation and red cell damage. Improvements in intravascular laser delivery systems are required before clinical application. The fibre-optic catheter to view and target obstructed sites and the use of the laser cautery cap to vaporise the plaque or thrombus will be helpful in this regard. [ABSTRACT FROM PUBLISHER]