Arterial dissections

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Arterial dissections
Aortic dissection
SpecialtyVascular surgery

An arterial dissection is a tear within the wall of an artery, which allows blood to separate the wall layers. There are several types. Usually, a tear is in an arterial wall, but a vein wall tear has been documented.[1]

By separating a portion of the wall of the artery (a layer of the tunica media or in some cases tunica intima), a tear creates two lumens or passages within the vessel, the original or true lumen, and the false lumen created by the new space within the wall of the artery. It is not yet clear if the tear in the innermost layer, the tunica intima, is secondary to the tear in the tunica media. Dissections originating in the tunica media are caused by disruption of the vasa vasorum. It is thought that dysfunction in the vasa vasorum is an underlying cause of dissections.[2]

Description

Arterial dissections become life-threatening when growth of the false lumen prevents

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.

MRI 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

malperfusion
due to occlusion of the true lumen of the aorta by the false lumen.

Types

Examples include:

Carotid and vertebral artery dissection are grouped together as "Cervical artery dissection" (CeAD).

Common features

As a disease family, arterial dissections share common features, including shared genetic risk variants, and commonly perturbed molecular pathways.

vascular smooth muscle cell gene SLC2A10 have all been implicated in at least two types of arterial dissection.[2]

References

External links