A type A aortic dissection involves the ascending aorta. Hypertension is the biggest risk factor. Unlike type B aortic dissection which involves only the descending aorta, type A dissection is a surgical emergency. Type B dissection is usually being treated medically.

The patients usually present with severe chest pain radiating to the back.

On the upper image above the true lumen (black arrow) is being compressed by the false lumen (labeled FL on the upper image). The involvement of the ascending aorta makes it a type A dissection.

Significant dilation of the aortic root (black arrow on the bottom image) is noted.

The patient underwent emergent replacement of the aortic valve, aortic root, ascending aorta, transverse arch and proximal descending aorta.