Microembolization of Cerebral Blood Flow during Coronary Artery Bypass Grafting in Conditions of Artificial Blood Circulation

Ischemic heart disease is one of the leading causes of disability and mortality worldwide. Despite the considerable progress in the field of pharmacotherapy of ischemic heart disease, it is not always possible to achieve the desired effect, which serves as the basis for the use of surgical methods of revascularization. Coronary bypass surgery is one of the most common surgical methods for the treatment of coronary artery disease and is traditionally performed in conditions of artificial circulation. Damage to the brain is one of the first places in the list of postoperative complications in cardiosurgical operations. In modern scientific literature, there are discussions of various mechanisms of damage to the brain in cardiosurgical patients, operated under the conditions of artificial blood circulation. The lack of common opinion in this issue justifies the need for additional research. The purpose of the study was to analyze the volume of cerebral microembolization in the basin of the middle cerebral arteries (MCA) during coronary artery bypass grafting (CABG) in conditions of artificial circulation (AC), and to investigate the relationship between cerebral microembolization and the development of postoperative cognitive disorders. Material and methods. The study included 34 patients (19 men and 15 women) who underwent CABG using AC. Monitoring of cerebral blood flow during the operation was carried out on the apparatus "Angiodin 2K" (Bios, Russia). Assessment of the patients' cognitive status was carried out using verbal and nonverbal tests. Evaluation was carried out twice, before surgery and on the fifth day after the operation. Results and discussion. Criteria for diagnosis of postoperative cognitive dysfunction (POCD) showed a decrease in the results of testing by 10% or more with a full study in two tests and more, and a decrease of 2 points or more in the tests of MOS and MMSE. These data indicated that all patients had microembolization of the cerebral blood flow after aortocoronary shunting under the conditions of artificial circulation. Its amount was more than 800 microemboli, which resulted in a clinically pronounced impairment of brain function in the early postoperative period (r = 0.77 p <0.05). Conclusions. The understanding of regularities of the emergence of postoperative cognitive dysfunctions is a powerful resource for obtaining positive results when performing CABG operations under the conditions of the AC.