Initiation
Both approaches begin with a median sternotomy and initiation of cardiopulmonary bypass (CPB), with the axillary, innominate, or femoral arteries used as sites for systemic perfusion and the superior and inferior vena cava used for venous outflow.13-16 A guidewire into the aortic true lumen is also sometimes introduced via the femoral artery at this point.13 Subsequently, hypothermic circulatory arrest (HCA) and selective anterograde cerebral perfusion (ACP) are established. ACP can be provided via the brachiocephalic trunk and left carotid artery, or via the carotid arteries directly in cases where the brachiocephalic trunk is cannulated for CPB.5 Myocardial protection can be facilitated via cold crystalloid cardioplegia (via a single infusion) or cold blood cardioplegia (infusions at 20-minute intervals). Aortic repair typically begins once the patient is cooled to a core temperature of 25ÂșC.11-13, 16-18 An alternative, branch-first, approach described by Matalanis et al. , which can potentially avoid deep hypothermia and circulatory arrest altogether can also be taken.19 Following medial sternotomy and initiation of CPB via both femoral and right axillary arteries, the brachiocephalic trunk is clamped and transected. It is then anastomosed to the first branch of a trifurcated Spielvogel graft (a trifurcated graft introduced by Spielvogel et al . consisting of a single, vertical graft with two shorter lateral branches, that facilitates anastomosis of the arch vessels to an arch graft proximal to the sinotubular junction).20 A similar approach is taken with the left common carotid, which is anastomosed to the second branch, while cerebral perfusion via the right common carotid is restored. Similarly, perfusion through the left common carotid is restored prior to clamping, resection, and anastomosis of the left subclavian.20Therefore, cerebral, cardiac, and distal perfusion is not interrupted at all during arch vessel anastomosis. Following successful arch vessel anastomosis, the arch is resected to the desired extent and the arch graft introduced.11, 16, 20