The initial clinical experience and quantitative angiographic results of percutaneous coronary excimer laser-assisted balloon angioplasty are described for 55 lesions in 50 patients. With use of a xenon chloride (308 nm) excimer laser generator and 1.5 to 1.75 mm catheters, excimer laser angioplasty was attempted at 135 ns pulse width, 25 to 40 Hz repetition rate, 2 to 5 s laser delivery lime and 30 to 60 mj/mm2energy fluence. Laser success (>20% reduction in absolute percent diameter stenosis) was achieved in 41 (75%) of 55 lesions, with 100% subsequent balloon angioplasty success (<50% residual stenosis).By quantitative digital caliper technique, the percent diameter stenosis (mean ± SE) was reduced from 81 ± 1 % to 50 ± 3% after excimer laser angioplasty (p < 0.001) and to 20 ± 1% after balloon angioplasty (p < 0.001); minimal luminal diameter increased from 0.56 ± 0.04 to 1.46 ± 0.08 mm (p < 0.001) and 2.03 ± 0.07 mm (p < 0.001), respectively. By videodensitometric techniques, the percent area stenosis decreased from 86 ± 2% to 54 ± 3% after excimer angioplasty (p < 0.001) and to 26 ± 3% after balloon angioplasty (p < 0.001).There were no perforations, need for emergency bypass surgery or deaths. The overall incidence of abrupt closure (3.6%), dissection (1.8%), embolization (1.8%), filling defect (6%), myecardial infarction (5.5%), side branch occlusion (3.6%) or spasm (3.6%) was infrequent and more related to subsequent balloon angioplasty than to the laser procedure. In the early follow-up period (range 1 to 10 months, mean 7), 36 (72%) of the 50 patients remained asymptomatic; symptoms recurred in 14 patients (28%) in relation to abrupt closure in the first 24 h in 2 patients (3.6%), late closure in the first week in 2 patients (3.6%) and restenosis in 10 patients (20%).Thus, percutaneous coronary excimer laser angioplasty appears to be a feasible and safe procedure in selected patients. At present, the procedure is undergoing significant development, including modification of the delivery catheters and operating techniques. The impact of this technology on the angioplasty restenosis rate awaits further follow-up analysis.
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