Investigating the Difference between Two Cannulation Angles of the Ascending Aorta in Preventing Cerebrovascular Events after Coronary Artery Bypass Grafting

Dear Editor, Today, with the increasing number of open cardiac surgeries, complications such as cerebrovascular events, inflammatory complications, tissue damage, and organ failure have increased, which can be associated with CPB and ancient aortic cannulation.[1] One of the important complications after open cardiac surgery is the occurrence of arterial embolization, which can be catastrophic, especially in areas of the body, including the brain. The causes of this complication can be due to the detachment of fragments from the aortic wall, air embolism caused by the CPB machine, embolism caused by carotid artery atheroma, and changes in blood flow and velocity. In this regard, the occurrence of atherosclerosis in the ascending aorta and its arch, which is the site of typical aortic cannulation, can be very important. This is because the position of the aortic cannula, the angle of its insertion into the aorta, and ultimately the possibility of embolization from the wall and embolization into the carotid arteries are very important.[2,3] It is well known that the jet velocity of blood flow exiting the tip of the aortic cannula can cause embolization distal to the carotids and complications such as transient ischemic attack (TIA), transient neurological deficit (TND), and permanent neurological deficit (PND).[4,5] Therefore, aortic cannulation techniques such as cannula position, cannula angulation, and cannula location during CPB can cause changes in aortic shear stress and aortic blood turbulence and can cause dangerous complications such as cerebral vascular events through the occurrence of blood borne embolization.[6,7] Although the incidence of CVA after CABG surgery is uncommon, it seems that its incidence will be much lower with changes in the cannulation angle. Therefore, we have found that cannulation of the aorta along the longitudinal axis of the ascending aorta (traditional method) may be associated with a higher incidence of significant neurological complications in the postoperative period after cardiac surgery than cannulation at a 45-degree angle to the longitudinal axis of the ascending aorta (new method). Previous studies have shown that alternative methods such as axillary artery cannulation have reduced the incidence of cerebral stroke after surgery, and some simulation and dynamics studies have also indicated the effect of changing the angle of cannulation on blood flow and velocity.[2–5] The letter also states that our new method may also reduce cerebrovascular events by reducing the likelihood of plaque dislodgment and subsequent embolization. In fact, the use of the new aortic cannulation method can be associated with a very low incidence of cerebral stroke and minor cerebral events compared to the traditional method. It should be noted that in the traditional method, the aortic cannula is inserted parallel to the longitudinal axis of the ascending aorta, whereas in our new method, the aortic cannula is inserted at a 45-degree angle to the longitudinal axis of the ascending aorta. This modification in the angle of ascending aortic cannulation can significantly reduce the incidence of catastrophic neurological complications in the early postoperation after open cardiac surgery, which can be associated with improved surgical outcomes and improved quality of life for patients. Therefore, it is recommended that cardiac surgeons pay special attention to the angle of aortic cannulation. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.