test 6

Question 1

Ascending Aorta location

Answer 1

 Begins at the AV annulus and extends to the proximal innominate artery

Question 2

Transverse Arch location

Answer 2

 Where 3 brachiocephalic
branches arise
 Treatment for Ascending and Transverse Arch are very
similar.

Question 3

Descending Thoracic and Thoracoabdominal Aorta location

Answer 3

 Lies just beyond the left subclavian to the aortoiliac bifurcation

Question 4

Aortic dissection

Answer 4

 Occurs when blood penetrates the intima of the Aorta
 Creates an expanding hematoma between medial layers
 True lumen is not usually dilated (stays the same size)
 Compressed by dissection
 Branching vessels may not be affected

Question 5

Aortic aneurysm

Answer 5

 Dilation of all 3 layers

Question 6

Aortic dissection incidence

Answer 6

 According to European Autopsy Study
 Occurs in 3.2 dissections per 100,000 autopsies
 Results in more deaths than aneurysm rupture

Question 7

AORTIC DISSECTIONS causes

Answer 7

 History of hypertension
         Present in ~90% of patients
 Advanced age
         >60 years
 Sex
         Male, <60 years
 Marfan’s syndrome
 Congenital Heart Disease
         Coarctation, Bicuspid aortic valve
 Other causes
         Toxins and diet
 Increased Physical Activity
 Emotional Stress
 Blunt Trauma
 Cannulation for bypass
        - femoral most common

Question 8

Aortic Dissection mechanism

Answer 8

 Intimal tear
 Presence of a weakened aortic wall
 Areas experiencing greatest mechanical shear forces
 Points where the aorta is fixed, there is increased shear stress applied to the aortic wall.

Question 9

Aortic dissections occurance in parts of the aorta

Answer 9

- Most common to least common
 Ascending (61%)
 Descending (24%)
 Arch (9%)
 Abdominal (3%)

Question 10

AORTIC DISSECTIONS Propagation

Answer 10

 Occurs within seconds
 Driven by pulse pressure and ejection velocity
 Origin of arteries (including coronary arteries) may be involved in Aortic Dissections
 Vessel occlusions can also occur
 Due to compression by the false lumen.

Question 11

AORTIC DISSECTION –

CLASSIFICATIONS - DeBakey Classification

Answer 11

 3 types based upon location of intimal tear and which section of the aorta is involved

Question 12

DEBAKEY CLASSIFICATION Type I

Answer 12

 Intimal Tear: Ascending Aorta

 Dissection: All parts of thoracic aorta (ascending, arch, and descending)

Question 13

DEBAKEY CLASSIFICATION Type II

Answer 13

 Intimal Tear: Ascending Aorta
 Dissection: Ascending Aorta only
 Stops before innominate artery

Question 14

DEBAKEY CLASSIFICATION Type III A and B

Answer 14

 Type IIIA
         Intimal Tear: Descending Aorta
         Dissection: Descending Thoracic only distal to left subclavian, ends above diaphragm
 Type IIIB
         Intimal Tear: Descending Aorta
         Dissection: Below diaphragm

Question 15

AORTIC DISSECTION – STANFORD (DAILY) CLASSIFICATION

Answer 15

 Type A (DeBakey I and II) - outcomes are not good
 Ascending Aorta
 Any involvement regardless of where tear is
 Regardless of how far it propagates
 Usually emergent/ urgent cases
 More virulent course
 Type B
 Distal aorta
 Any part of aorta distal to left subclavian

Question 16

Cause of tear in the thoracic artery

Answer 16

 Majority occurs after a trauma
 Involve deceleration injury (MVA)
 Large shear stress on points of aortic wall that are relatively immobile.
 Leads to immediate exsanguination and death
 10-15% are lucky
 Maintain the integrity of the adventitial covering of the aortic lumen
 Survive to emergency care

Question 17

THORACIC ARTERY RUPTURE - LOCATION

Answer 17

 Most occur distal to the origin of the left subclavian artery
 Due to fixation at the point of the ligamentum arteriosum
 2nd most common site
 Ascending aorta just distal to the Aortic Valve.

Question 18

AORTIC DISSECTIONS - PROGNOSIS for untreated ascending dissection

Answer 18

 DISMAL
 2 day mortality – 50%
 3 month mortality – 90%
 Usual cause of death
         Rupture of the false lumen into the pleural space or pericardium

Question 19

AORTIC DISSECTIONS - PROGNOSIS with DeBakey Type III or Stanford B dissections

Answer 19

 Lower incidence
 Distal to head vessels and lower pressures
 GI or renal complications
 Other causes of death
 Progressive heart failure (AV involvement)
 MI (Coronary Involvement)
 Stroke (Occlusion of cerebral vessels)
 Bowel Gangrene (Mesenteric artery occlusion)

Question 20

AORTIC DISSECTIONS Surgical Mortality

Answer 20

 3-24%
 Depends on affected section of aorta
 Aortic Arch – Highest mortality
 Descending Thoracic – lowest mortality