Transmyocardial laser revascularization with a high-power (800 W) CO 2 laser: clinical report with 50 cases

Abstract

This paper reports the clinical experience in transmyocardial laser revascularization ( TMLR) with high power CO 2 laser and evaluates the preliminary results of TMLR. Methods: TMLR was performed on the beating heart in 50 cases underwent a left anterolateral thoracotomy in the fifth intercostal space. The laser energy of each discharge and the percentage of successful transmyocardial penetration in free walls of the left ventricle were studied. Myocardial enzymes were measured postoperatively by the enzyme dynamic method during a week. The follow-up ranged from 3 to 18 months was made to assess angina class and myocardial perfusion. Results Creatine phosphokinase isoenzyme (CPK-MB) had increased since 2 hours after TMLR, but the peak value of CPK-MB at 24 hours was less than 2-fold of the baseline(15 IU/L±10IU/L). The average laser energy used for making each channel was 35.6±12.3J. The percentage of successful penetration was 93.6%. The laser energy used in apex was the most (P<0.05). The mean angina class (Canadian Cardiovascular Society) was significantly improved (2.1±0.3) at 3 months after operation than the average baseline angina class of 3.7±0.7( P<0.01) and was further improved during 6∼12 months (1.7±0.3,P<0.01). 201 TI -SPECT showed a remarkbale improvement in reversible ischemia in seventy percent of followed-up patients. The mortality during hospitalization was 2%. Conclusion: TMLR may improve angina pectoris and myocardial perfusion significantly. To switch on the laser in proper order may be helpful to shorten duration of surgery. A gentle removal of fat on the apex may increase the successful transmyocardial penetration.