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