Abstract

Increasing understanding of the mechanisms of cerebral injury and physiology of brain protection during operations on the aortic arch has led to important developments of protective methods in the last 30 years. Hypothermia is the principal element of all current methods of brain protection. The limited time available for safe conduct of the reconstruction under the conditions provided by deep hypothermic circulatory arrest was appreciated early on. All other adjunctive methods, i.e. selective antegrade cerebral perfusion or retrograde cerebral perfusion were originally developed as an alternative to circulatory arrest or in an attempt to safely prolong the duration of the circulatory arrest. Even with the adjuncts of retrograde cerebral perfusion and to a lesser extent selective cerebral perfusion, there is a serious time pressure to complete the operation rapidly in order to limit the period of “total cerebral protection time”. Surgical steps in the reconstruction of the aortic arch were modified in response to this essential requirement. The changes in the conduct of the operation also involved the sites of arterial inflow for perfusion. The innovative steps in the reconstruction of the arch and the changes in the perfusion routes occurred simultaneously and both had an additive effect in the improved outcome of these complex operations. The following is a synopsis of these innovations from a historical point of view followed by the description of our preferred current technique of arch replacement which incorporates some of these innovations and provides continuous antegrade cerebral perfusion and virtually eliminates any period of interruption of brain perfusion.