"Branch-first" continuous perfusion aortic arch replacement and its role in intra-operative cerebral protection.

Abstract

Surgery of the aortic arch remains one of the most challenging areas of cardiac surgery. Despite the advancements and refinements in surgical and perfusion techniques over the last 30 years, mortality, morbidity, and in particular the incidence of cerebral injury, remains higher than that reported in procedures performed on the more proximal aorta. The brain is the most oxygendependent organ in the body and many steps during aortic arch replacement have the potential to cause cerebral injury, either as a result of temporary interruption to its blood supply or the introduction of gaseous or particulate emboli. Traditional approaches have focused on the use of two concepts to limit cerebral injury during arch replacement. Firstly, the use of profound hypothermia to reduce cerebral metabolic demands combined with surgical haste to minimize periods of cerebral ischemia; and secondly, the addition of various techniques of cerebral perfusion (antegrade and/or retrograde) in an attempt to prolong the period of “safe” circulatory arrest.