Aortic Dissection

AORTIC DISSECTION

An aortic dissection is a life-threatening emergency in which there is a tear in the intima of the aorta so that the intima and media separate. This creates a false lumen through this area where blood passes. This can happen anywhere along the length of the aort and will extend to involve other arteries above and below the dissected area. This is a more common complication among the elderly, black people, and those with hypertension. Those with a connective tissue disorder, such as Marfan syndrome or Ehlers-Danlos syndrome have a greater chance of having this complication as well.

There are different ways to classify an aortic dissection, usually according to anatomic location. The most widely-used classification system is the DeBakey system, which classifies dissections by where they are located. About half of all dissections start in the ascending aorta and reach up to the aortic arch. They tend to occur where the greatest amount of hydraulic stress is found, such as the first five centimeters of the ascending aorta on the right lateral wall as well as on the proximal descending aorta past the left subclavian artery.

A dissection rarely happens if the aorta is normal. In situations where there is a connective tissue disease, hypertension, or atherosclerosis, the aortic wall is already damaged and a dissection is more likely to occur. The consequences are great, including compromise of nearby arteries, aortic valve regurgitation, heart failure, and aortic rupture.

The patient with an acute aortic dissection will describe the abrupt onset of tearing or ripping pain in the upper chest or back. About one-fifth of patients have syncope for a variety of reasons, including active bleeding or severe pain with syncope. If perfusion of major organs is involved, there can be symptoms related to intestinal infarction, myocardial infarction, and stroke, among other complications). The major pulses might be interrupted or limb pulses might differ from side to side. Half will have an acute aortic regurgitation murmur. Arterial supply to any major branch of the aorta can be obstructed.