BACKGROUND Over the past 20 years, there are many studies, where great attention is paid to the gas and material embolism as the cause of cognitive impairment in patients undergoing surgery with cardiopulmonary bypass. OBJECTIVE To identify the filter capacity of 4 extracorporeal circuits for removing gaseous microemboli in various interventions on the heart and aorta. METHODS Work carried out on 60 patients operated on acquired heart and aorta under cardiopulmonary bypass. We used 4 different extracorporeal circuits, divided into groups of 15 patients. Quality and quantity of gaseous microemboli recorded in real time on the device BCC-200 GAMPT (Germany). RESULTS According to two indicators: Vol. Red (reduction in the volume of gas microemboli) and Fl (filter index) the best results were obtained after statistical processing systems Medtronic and Terumo, followed by Maquet system and Eurosets. CONCLUSIONS BCC-200 device allows identifying the sources of gaseous microemboIi. The perfusionist, having on-line information time about the number of microemboli coming in heart-lung machine can increase patient safety, using the capabilities of a particular extracorporeal circuit and minimize the amount of emboli from entering the patient's arterial line.