Acute aortic syndromes which are called variants of aortic dissection
Penetrating atherosclerotic ulcer is a focal tear of the intima caused by ruptured plaque, leading to ulceration into the aortic wall. It is different from a dissection because a dissection is not focal, but rather propagates along the length of the vessel.
Intramural hematoma is a hemorrhage into the wall of the vessel, generally between the inner and outer layers of the media. Intramural hematoma may occur without an intimal tear, such as secondary to rupture of the vasa vasorum (small blood vessels in the wall of the aorta); this is usually secondary to hypertension but can be caused by trauma. Alternatively, it may be associated with an intimal tear, such as secondary to a penetrating aortic ulcer.
A recently described entity, known as a limited intimal tear, is diagnosed when there is a shallow tear of the intima, without extension of the tear to form a false lumen.
Warning : These terms can become extremely confusing because one form of an aortic pathologic condition can lead to another. In part because of this confusion in terminology, there are numerous controversies in the surgical literature regarding prognosis and management of the “dissection variants.”