Engelsk definition
A tear or separation of the layers by a blood vessel typically involving vessels under pressure, i.e., ARTERIES, e.g., AORTA. Tearing of the TUNICA INTIMA layer of a blood vessel may lead to interstitial HEMORRHAGE. Dissection between the tunica intima and TUNICA MEDIA causes luminal occlusion. Dissection at the media, or between the media and the outer ADVENTITIA causes aneurismal dilation.