Restenosis of the coronary stenotic lesions treated by holmium:YAG laser coronary angioplasty

Clinical efficacy of newly developed Holmium YAG laser coronary angioplasty (HLCA) was assessed for 30 patients with angina. There were 12 near left main trunk (LMT) lesions and 4 aorto- ostial lesions. Adjunctive balloon angioplasty was performed for 25 of 30 lesions. Delivered energy ranged from 1.5 to 2.5 watts/pulse and the total exposure time ranged from 6 to 55 seconds. External diameter of laser catheter was 1.5 mm for 13 lesions, 1.4 mm for 17 lesions, and 1.7 mm for 5 lesions. Laser success, defined as 20% reduction of stenotic ratio, was obtained in 21 of 30 (70%) and overall procedural success rate was 93%. There were 3 cases with acute coronary occlusions relieved by adjunctive balloon angioplasty and one coronary perforation without manifestation of cardiac tamponade. There were no large coronary dissection which involved more than 5 mm of the coronary artery. Follow up coronary angiography after 3 months showed restenosis in 14 of 27 patients (52%). Percent stenosis after lasering (56%) was similar to that at 3 months after (62%). HLCA is acutely effective treatment for lesions near LMT, because of low incidence of large coronary dissection. However, angiographical restenosis rate is high at 3 months after HLCA. This may be attributed to the relatively large residual stenosis after the procedure and vessel injury caused by shock wave.