ULTRASTRUCTURAL CHARACTERISTICS OF ERYTHROCYTES AND THEIR RELATIONSHIP WITH OXYGEN TRANSPORT IN PATIENTS WITH CORONARY HEART DISEASE AFTER CORONARY ARTERY BYPASS GRAFTING

Abstract

TYPE: Abstract TOPIC: Cardiothoracic Surgery PURPOSE: Evaluation of nanostructural and micromechanical red blood cells (RBC) characteristics and their relationship with oxygen transport function after isolated on-pump coronary artery bypass grafting (CABG). METHODS: 30 IHD patients underwent standart CABG procedure with cardiopulmonary bypass(CPB). RBC scanning was performed on a «Bioscope Catalyst» atomic force microscope (AFM) (Bruker, USA). The micromechanical properties were investigated with the «PFQNM-LC-A-CAL» conveyors. The following were recorded: the RBC diameter, the height of their side, area, volume, membrane rigidity, adhesion strength, Young's modulus, elastic deformation. For oxygen transport evaluation oxygen delivery index (DO2I), consumption index (VO2I), and extraction ratio (O2ER) were calculated. RESULTS: On the next day after CABG, a decrease in DO2I, VO2I, and O2ER by 14%, 33% and 16% was recorded respectively, indicating a limitation of gas transport blood function. RBC showed an increase in area by 35%, diameter by 6%, volume by 19%, and the height of the side by 5 times. At the same time, multidirectional changes of micromechanical properties of RBC membranes were noted: Young's modulus and stiffness decreased by 3.2 and 2 times, respectively; the adhesion force increased 2.7 times, and the whippy-elastic deformation – up to 2.2 times. Correlation analysis showed the presence of reliable correlations between oxygen transport indicators and biomechanical RBC membranes parameters CONCLUSIONS: Analysis of nanostructural RBC parameters and oxygen transport indicators expands the pathophysiological mechanisms understanding of postperfusion disorders. CLINICAL IMPLICATIONS: improvement and personification of approaches to cardiopulmonary bypass DISCLOSURE: Nothing to declare. KEYWORD: atomic force microscopy