Aortic Aneurysm Location 1

Question

Vignette: A 45-year-old woman presents to the emergency department with sudden onset of severe chest pain radiating to the back. Her blood pressure is 180/110 mmHg and her pulse is 110 bpm. An urgent CT scan reveals a dissecting aortic aneurysm. During her subsequent surgery, the surgeon notes that the aneurysm is located immediately distal to the origin of the left subclavian artery. The aneurysm is most likely located in which part of the aorta?

Choices

A. Ascending aorta

B. Aortic arch

C. Descending thoracic aorta

D. Abdominal aorta

E. Sinus of Valsalva

Answer

C. Descending thoracic aorta

Explanation

The aorta is divided into four parts: the ascending aorta, aortic arch, descending thoracic aorta, and abdominal aorta. The left subclavian artery is the last branch of the aortic arch. Therefore, an aneurysm located immediately distal to the left subclavian artery's origin is most likely in the descending thoracic aorta. The ascending aorta extends from the left ventricle to the aortic arch and includes the coronary arteries. The aortic arch gives rise to three branches: the brachiocephalic trunk, left common carotid artery, and left subclavian artery. The descending thoracic aorta extends from the aortic arch to the diaphragm, and the abdominal aorta extends from the diaphragm to the bifurcation into the common iliac arteries. The sinus of Valsalva is located in the ascending aorta and is not distal to the left subclavian artery.