The Effects of Excimer Laser Coronary Angioplasty in Calcified Lesions : Investigation with Intravascular Ultrasound

ABSTRACT

BACKGROUND: Coronary artery target lesion calcification may be an important determinant of the arterial response to catheter therapy for coronary arterial disease. The excimer laser coronary angioplasty(ELCA) has been reported to be a promising treatment for complex coronary artery disease. However, the effects of ELCA is not well known against the calcified target lesion. METHODS: To assess the arterial and plaque remodeling in calcified lesions after excimer laser coronary angioplasty, we used a comprehensive intravascular ultrasound(IVUS) imaging system(25MHz rotation transducer, 3.9 Fr monorail imaging sheath, motorized transducer pull back at 0.5mm/sec and quantification) to study 23 patients(1 left main, 10 LAD, 4 LCX, 6 RCA, 2 SVG) before and immediately after ELCA(the AIS 308nm XeCl excimer laser, pulse width >200nsec, pulse frequency 20Hz, energy density 35-65mJ/mm2). Paired before and after ELCA image slices were analysed ; and extermal elastic membrane, lumen, plaque+media(P+M) and calcium cross-sectional area(CSA) measured; and their differences after ELCA calculated. RESULTS: The IVUS results about the therapeutic effects of ELCA showed the enlargement of lumen CSA from 1.5+/-0.4 to 3.2+/-0.9mm2(p<0.001) and decreased of P+M CSA from 14.6+/-3.8 to 13.4+/-3.6mm2(p<0.001) without arterial expansion. The decrease of calcium CSA from 1.8+/-0.7 to 1.5+/-0.6mm2(p<0.001) and the formation of small, superficial fissures within the calcified plaque(15/23 lesions) were noted. The number of small fissures correlate with the calcium CSA significantly(r=0.61, p<0.001). CONCLUSION: The plaque and calcium ablation is the main effects of ELCA in calcified lesion, and the calcium ablation and fissure formation after ELCA may contribute to decrease the dissection and improve the success after ajunctive PTCA.