Aortic Aneurysm/surgery; Aortic Dissection/surgery; Blood Vessel Prosthesis Implantation/methods; Cerebrovascular Circulation; Heart Arrest, Induced/methods; Hypothermia, Induced/methods; Operative Time; Perfusion/methods; Acute Disease; Adult; Aged; Aortic Dissection/diagnostic imaging; Aortic Dissection/physiopathology; Aortic Aneurysm/diagnostic imaging; Aortic Aneurysm/mortality; Aortic Aneurysm/physiopathology; Blood Vessel Prosthesis Implantation/adverse effects; Blood Vessel Prosthesis Implantation/mortality; Female; Heart Arrest, Induced/adverse effects; Heart Arrest, Induced/mortality; Hospital Mortality; Humans; Hypothermia, Induced/adverse effects; Hypothermia, Induced/mortality; Kaplan-Meier Estimate; Male; Middle Aged; Perfusion/adverse effects; Perfusion/mortality; Postoperative Complications/etiology; Postoperative Complications/mortality; Preliminary Data; Risk Factors; Time Factors; Treatment Outcome