Vasoreactivity and structure of human coronary arteries irradiated by excimer laser.

ABSTRACT In this study the effects of excimer laser (308 nm) angioplasty on arteries have been studied. We report histology and vasoreactivity properties of human atherosclerotic and normal coronary arteries and bovine coronary arteries after exposure to pulsed excimer laser irradiation. Segments of isolated and pharmacologically active human coronary arteries were obtained within 5–8 hr postmortem. Segments of bovine arteries were obtained from fresh hearts. Side branches were ligated and vessels perfused with Krebs–Ringer's–bicarbonate solution in a perfusion apparatus to maintain their viability. Excimer laser irradiation was performed using a fused silica fiber advanced through the artery within a polyethylene canula to assist with steerability and to protect against perforation. The fiber delivered a total of 40–60 J at its tip at 100 mJ/pulse at 15 pulses/sec. A total of 5 human atherosclerotic, 2 human normal, and 8 bovine arteries were used. Ablation of plaque was accomplished with remarkable ease...