TRANSMYOCARDIAL LASER REVASCULARIZATION - HISTOPATHOLOGICAL FINDINGS

Transmyocardial laser revascularization (TMLR) is a new surgical techn ique clinically tested in patients with advanced seven coronary arteri osclerosis when classic routine treatment by medicaments, percutaneous transluminal coronary angioplasty (PTCA), or aorto-coronary bypass su rgery does not improve symptoms of ischemic heart disease. During the procedure high-energy CO2 laser performs 35-40 transmyocardial channel s via left-sided thoracotomy. Channels are drilled from the epicardial side of the heart through the myocardium into the left ventricle cavi ty. Impulses are synchronized with EKG (diastole), the channel diamete r is about 1 mm. Transmural laser penetration is confirmed by intraope rative transesophageal echocardiography (TEE). This technique is based on a theory that channels allow blood supply from left ventricle dire ctly into the intramyocardial vessels (possibly capillaries) and so im prove oxygenation of ischemic myocardium. Presented are gross and micr oscopic findings in a 75-year-old woman who suffered from classic clas s IV angina with shortness of breath. She had a history of an inferior myocardial infarct, ventricular tachyarrhythmia, aorto-coronary bypas s, and mitral valvuloplasty. Her ejection fraction by echocardiography was 25%. Angiographically, she had multiple occlusions of native coro nary arteries and diffuse distal stenosis in the graft of the left int ernal mammary artery (LIMA) to the left anterior descending coronary a rtery (LAD). Thirty six of forty laser pulses were confirmed by TEE as transmural. The patient died suddenly of ventricular fibrillation 5 d ays after TMLR surgery. The autopsy was performed 6 hours after death. After cross-sectioning of the heart all the laser-bored channels were found partially or completely filled by fibrin and cell infiltrate co mposed mainly of polymorphonuclear leukocytes. Patent channels were fo und within myocardial scars, channels performed through viable myocard ium appeared to be partially collapsed and occluded. (C) 1998 by Elsev ier Science Inc.