Basic studies were carried out on the treatment, with
argon laser and balloon dilatation
catheter, of stenotic arteries resulting from
atherosclerotic plaque. Seventeen rabbits approximately 34 weeks old and weighing between 3 and 4 Kg were used. Each rabbit was fed a 1%
cholesterol diet for 3 to 4 months to induce atherosclerotic lesions in the carotid arteries and the aorta. The
argon laser unit used was a Model 20 Endocoagulator (HMG, Inc.; maximum power, 12W). Under an
angioscope, two bare-ended
laser probes (1.5 mm and 0.3 mm in diameter) were used to vaporize
atheromatous plaque in the aortas of 10 rabbits, and a
metal tip
laser probe in the case of seven rabbits. The plaque remaining after this laser angioplasty was compressed to the
luminal surface through inflation of a balloon
catheter (balloon angioplasty) in order to sufficiently dilate the arteries. The animals were then sacrificed and examined both macroscopically and microscopically. When the bare-ended probes were used, there was a change in the depth of vaporization in line with the direction of the
laser beam. Using a
laser heating power of 25 J, perforation of the vessel wall was observed in 36% of the trials. A higher frequency of perforation was seen with the 0.3 mm probe than with the 1.5 mm probe. However, a constant vaporizing effect was achieved using the
metal tip
laser.(ABSTRACT TRUNCATED AT 250 WORDS)