Continuous perfusion "Branch-first" aortic arch replacement: a technical perspective.

Abstract

The following video, along with the in-depth perspective article published elsewhere in this issue, aims to take you through the significant steps and the theoretical aspects of aortic arch replacement using the “Branch-first” continuous perfusion technique (Video 1). Video 1 Continuous perfusion “Branch-first” aortic arch replacement: a technical perspective In essence the procedure consists of 5 major steps: Establishment of cardiopulmonary bypass using femoral inflow and moderate hypothermia; Serial disconnection and reconstruction of each arch branch (proceeding from innominate to left subclavian) using a trifurcation arch graft with a perfusion side arm port (TAPP graft, Vascutek Ltd., Renfrewshire, Scotland, UK). Following completion of the innominate anastomosis, the perfusion side arm port is used for selective antegrade cerebral perfusion for the remainder of the procedure; Clamping of the proximal descending aorta and construction of the distal arch anastomosis; Completion of aortic root reconstruction; Connection of the common stem of the trifurcation graft to the ascending aortic graft. Collateral network and individual proximal arch branch clamping A basic principle of the “Branch-first” technique is the richness of the collateral network that exists between the 3 arch branches and between the arch branches and the upper and lower body. Apart from the circle of Willis, there are a number of extra-cranial collateral channels that augment cerebral perfusion during individual clamping of each branch vessels (1,2). These collateral channels include: Those between the external and internal carotid arteries; The right and the left carotid arteries; The upper and lower body; The subclavian and carotid arteries. These extracranial collaterals allow for a short period of occlusion of one branch while the other two branches perfuse its territory. Typically with this technique, anastomotic times for each individual branch vessel are performed in approximately 10 minutes and we rarely see changes in ipsilateral cerebral oxygenation during this period. On the infrequent occasion that this does occur, alteration of systemic or head circuit flows generally brings cerebral oxygenation back to baseline levels.