Intramyocardial partial oxygen pressure in patients undergoing transmyocardial laser revascularization and bypass surgery

Abstract

Objective—Numerous investigations could not clarify the exact mechanism of transmyocardial laser revascularization (TMLR). The aim of this study was to investigate, whether TMLR leads to an increase of myocardial oxygenation in comparison to patients undergoing coronary artery bypass grafting (CABG).Design—Twelve patients (TMLR group) underwent TMLR alone with an 800 W CO2laser through a left anterior thoracotomy. Seventeen patients (CABG group) underwent standard CABG. Myocardial oxygenation was determined by measuring intramyocardial partial oxygen pressure (ptiO2). PtiO2was measured online and mean values at 1, 24, 32, and 48 h postoperatively were compared with baseline before intervention. Parameters influencing ptiO2(arterial pO2, hemodynamic parameters, hemoglobin) were recorded.Results—Mean baseline ptiO2was significantly lower in the TMLR group compared with the CABG group (p < 0.05). In both groups ptiO2increased significantly in the postoperative course, whereby ptiO2in the TMLR group was significantly lower compared with the CABG group.Conclusion—Although the exact mechanism of action of TMLR remains unclear, ptiO2and thus oxygen supply in the myocardium increased in patients undergoing TMLR at least in the early postoperative course. However, ptiO2increased to a lesser extent compared with CABG.