 Complex surgery of the ascending thoracic aorta and the aortic arch requires use of cardiopulmonary bypass CPB with moderate or profound total body hypothermia and circulatory arrest. As expected, coagulation disorder can be common and severe requiring multiple transfusions of blood product, which, in turn, is associated with increased risk of morbidity and mortality. Over the years, many techniques have been employed to ameliorate CPB- related bleeding with some agents such as aprotinin proving to be efficacious but centered in controversy either because of high cost or due to safety concerns. 