Arterial dissections become life-threatening when growth of the false lumen prevents
perfusion of the true lumen and the related end organs. For example, in an
aortic dissection, if the
left subclavian artery orifice were
distal to the origin of the dissection, then the left subclavian would be said to be perfused by the false lumen, while the
left common carotid (and its end organ, the
left hemisphere of the brain) if
proximal to the dissection, would be perfused by the true lumen proximal to the dissection. of an aortic dissection
1 Aorta descendens with dissection
2 Aorta isthmus Vessels and organs that are perfused from a false lumen may be well-perfused to varying degrees, from normal perfusion to no perfusion. In some cases, little to no end-organ damage or failure may be seen. Similarly, vessels and organs perfused from the true lumen but distal to the dissection may be perfused to varying degrees. In the above example, if the aortic dissection extended from proximal to the left subclavian artery takeoff to the mid descending
aorta, the
common iliac arteries would be perfused from the true lumen distal to the dissection but would be at risk for
malperfusion due to occlusion of the true lumen of the aorta by the false lumen. == Types ==