As a result of insufficient filtration with the prolongation of the duration of coronary artery surgery, various temporary

and/or permanent damage. For this reason, damage detection and risk assessment in the arterial filter is of vital importance. The arterial filter is the last point of blood circulation in the extracorporeal circulation mechanism. Studies have shown that the arterial filter minimizes the risk of gas embolism and related complications. However, prolonged use of the arterial filter may cause damage to the filter structure. This damage that may occur is; embolism risk, inflammation, blood damage, decrease in cerebral protection etc. can cause complications. The importance of the arterial filter in the cardiopulmonary bypass circuit in the study; By keeping the flow, temperature and cardiopulmonary bypass times equal, the damage of the arterial filter, which is considered due to the prolongation of the cardiopulmonary bypass time, will be monitored by electron microscopy, and its importance in the detection of damage and predicting the risks will be emphasized. In this study, the damage caused by examining the images of the arterial filters in the electron microscope will be determined and the risks that may occur as a result of the detected damage have been investigated.