Cross-clamp and Open arch repair:
We routinely cross-clamp the mid ascending aorta once antegrade true
lumen perfusion is established through central aortic or axillary artery
cannulation. As soon as the cross-clamp is applied, we carefully watch
the radial and femoral artery pressure lines for a few seconds. Rarely,
significant pressure changes may occur possibly indicating malperfusion,
in which case we release the cross clamp and continue with systemic
cooling till circulatory arrest.
After the application of the cross-clamp, the proximal aorta is
transected just above the level of sinotubular junction and direct
ostial cardioplegia is delivered to achieve cardioplegic arrest.
Once systemic cooling is achieved to the desired level, the cross clamp
is removed and circulatory arrest is commenced. Retrograde cerebral
perfusion is initiated. The ascending aorta and proximal arch are
excised. Additional arch segments are excised depending upon the extent
of the dissection into the arch vessels 37. Retrograde
flow of dark blood through the arch vessels is watched for. An open
hemiarch repair is often adequate. If an arch reconstruction beyond
hemiarch is required, retrograde cerebral perfusion is switched to
bilateral selective antegrade cerebral perfusion. We avoid the use of
Bioglue or hemostatic adhesive substances.
Once the arch repair is completed, the arch polyester graft is
cannulated and systemic antegrade cardiopulmonary bypass is resumed.
The goal is to maintain antegrade true lumen perfusion throughout the
conduct of the operation.