What is the aorta?
The aorta is the main blood vessel coming out of the heart. It carries blood to all parts of the body. It is shaped like a wooden walking cane, with the short end representing the ascending aorta (leading directly out of the heart), the horizontal handle representing the arch, and the long limb the descending thoracic aorta.
The ascending aorta begins at the aortic valve, and the first inch or two is called the aortic root. Diseases of the aortic valve may affect the surrounding root. The blood vessels supplying the heart itself, the coronary arteries, are affected at the aortic root making this a complex anatomical region.
The aortic arch is also complex, because the blood vessels to the head and arms (the brachiocephalic vessels) arise from it. The descending thoracic orta gives rise to the blood vessels that supply the spinal cord.
What is an aortic dissection?
The wall of the aorta is made up of three layers: an inner smooth layer (the intima), a muscular middle layer (the media ), and a tough outer layer (the adventitia).
If the middle layer becomes weakened and the inner layer is torn or disrupted in any way, blood may enter this inner layer and cause it to separate the way that plywood may separate between the sheets if left out in the weather. Because this separated wall is weakened and may rupture, dissection is a medical emergency that may require immediate surgery.
How would I know if I had a dissection?
Usually aortic dissection causes sudden severe chest or back pain. The pain may be so severe that the subject becomes light-headed or even passes out. The pain may be constant but more often it waxes and wanes.
The pain may move from the chest to the back and abdomen as the dissection itself progresses. It may be difficult to distinguish from a heart attack.
How is an aortic dissection treated?
Some acute dissections require immediate surgery, while others can be treated with blood pressure control medications. The results of surgery for aortic dissection, like for other surgery of the aorta, are best in centers with a special interest and experience.
Most recently there has been investigation into the use of endovascular stent grafts for the treatment of some types of dissection. The results of these studies are still being evaluated.