title: 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).
  
  
  METHODS
  Twelve patients (TMLR group) underwent TMLR alone with an 800 W CO2 laser through a left anterior thoracotomy. Seventeen patients (CABG group) underwent standard CABG. Myocardial oxygenation was determined by measuring intramyocardial partial oxygen pressure (ptiO2 ). PtiO2 was 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 ptiO2 was significantly lower in the TMLR group compared with the CABG group (p < 0.05). In both groups ptiO2 increased significantly in the postoperative course, whereby ptiO2 in the TMLR group was significantly lower compared with the CABG group.
  
  
  CONCLUSIONS
  Although the exact mechanism of action of TMLR remains unclear, ptiO2 and thus oxygen supply in the myocardium increased in patients undergoing TMLR at least in the early postoperative course. However, ptiO2 increased to a lesser extent compared with CABG.
authors.affiliation: Clinic of Cardiac Surgery, University Clinic of Schleswig-Holstein, Luebeck, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Misfeld
authors.forename: Jörg Ulrich
authors.initials: JU
authors.lastname: Rhau
authors.forename: Hans-Hinrich
authors.initials: HH
authors.lastname: Sievers
authors.forename: Ernst-Günter
authors.initials: EG
authors.lastname: Kraatz
mesh_terms: D000368:Aged; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000601:surgery*; D005260:Female; D006801:Humans; D053685:Laser Therapy; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods*; D009206:Myocardium / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis*; D010313:Partial Pressure
chemical_list: D010100:Oxygen