The aorta is the main artery in the human body. It originates at the aortic valve in the left ventricle of the heart and runs through the chest into the abdomen where it splits into two arteries. It carries oxygenated blood from the heart to all parts of the body. The aortic wall has a layered construction consisting of an inner (intima), middle (media) and outer (adventitia) layer.
Acute aortic dissection is a serious, potentially life threatening condition, in which the inner layer of the aorta (the intima) tears. Blood gushes through the tear and causes separation of the inner from the middle layer along a variable length of the aorta. This gives the aorta a typical double barrel appearance on imaging with blood flowing in the original, true, lumen and in the newly formed channel, the false lumen. (See figure 1.) The blood filled false channel may rupture through the outer layer causing an invariably fatal internal bleeding.
Aortic dissection is a rare phenomenon. It occurs in less than 10 people per 100000 per year. It affects usually men in their 60 and 70s.