Pathoma: Aortic Dissection and Aneurysm

Question 1

What is an aortic dissection?

Answer 1

Blood rips through the tunica intima and into the tunica media and then separates these layers of tissue.

Question 2

The predisposing factors for aortic dissection are ______________.

Answer 2

hypertension (such as found in the proximal 10 cm of the aorta) and weakness of the connective tissue in the tunica media

Question 3

Weakness of the tunica media occurs from __________.

Answer 3

hypertension

Question 4

Why does hypertension weaken the tunica media?

Answer 4

The smooth muscle cells in the outer half of the tunica media receive their oxygen from the vaso vasorum. Hypertension leads to narrowing of the vaso vasorum vessels, and thus the outer myocytes atrophy.

Question 5

Why do Marfans and Ehlers-Danlos lead to aortic dissection?

Answer 5

Because these are disorders of connective tissue!

Question 6

The most common cause of death in aortic dissection is ___________.

Answer 6

tamponade, because dissected aortas can bleed back into the pericardium

Question 7

Thoracic aneurysms result from ____________.

Answer 7

tertiary syphilis, which presents with tree-back appearance of the aorta

Question 8

The most common site of abdominal aortic aneurysms is ___________.

Answer 8

above the bifurcation and below the renal arteries

Question 9

Why does atherosclerosis result in aneurysm?

Answer 9

Because the thicker vessels create a longer distance for oxygen diffusion, and the outer wall is weakened

Question 10

Doctors worry about aneurysm rupture when the aneurysm is greater than _________.

Answer 10

5 cm