Objective: To evaluate cerebral perfusion using direct cannulation into the common carotid artery. A new technique is needed to protect brain ischemic injury during ascending aortic or aortic arch replacement. Methods: This technique was evaluated for patients who would have difficulty maintaining adequate cerebral perfusion during surgery. The procedure was performed when patients had the following diagnoses: pseudoaneurysm formation in contact with the sternum with the risk of aneurysmal rupture (n=5), acute aortic dissection with compression of the true lumen of the innominate artery by the pseudolumen (n=3), or a large volume of thrombus in the lumen of the aneurysm with the risk of cerebral thromboembolism if standard extracorporeal circulation was used (n=2). The perfusion catheter was cannulated into one side of the common carotid artery (right side: n=6, left side: n=4) and mean perfusion flow rate was found to be 175 mL/min. The operative procedures consisted of ascending aortic and aortic arch replacement with coronary artery bypass grafting in six patients, ascending aortic replacement in 2 patients, and innominate artery reconstruction/innominate artery and right subclavian artery reconstruction in one patient. Results: No cerebral accidents or deaths occurred while patients were hospitalized. We have followed up patients for a mean of 2.1 years (maximum 3.6 years), with no complications noted from the surgical procedure. Conclusions: Direct cannulation of the common carotid artery is a simple, safe, and acceptable cerebral protection for patients undergoing aortic or aortic arch replacement procedures in the patients with these specific conditions.