What part of the aorta is most commonly affected by aortic dissections?

The ascending aorta is the most commonly affected part during an aortic dissection due to its proximity to the heart and the high pressures generated during systole. Aortic dissections typically begin at the aortic root and can propagate both proximally and distally. In many cases, these dissections originate from a tear in the intimal layer of the aorta just above the aortic valve, which is located at the ascending aorta.

Dissections here can lead to significant complications, including aortic regurgitation, which occurs if the dissection extends into the aortic valve ring. The hemodynamic stresses in the ascending aorta, coupled with conditions such as hypertension and connective tissue disorders, also contribute to the higher incidence of dissections starting in this region. Understanding this is crucial for clinicians when assessing and managing patients with chest pain or signs of acute aortic syndromes.

The descending aorta, aortic arch, and abdominal aorta can certainly be involved in dissections, but they are less frequently the initial site of the tear compared to the ascending aorta.