Vascular Disease 2- Melissa (3)- Aneurysm*

Question 1

Define True Aneurysm and list the two types:

Answer 1

• arterial / ventricular wall is intact but THINNED
• blood remains within confines of circulatory system
  1. saccular (asymmetrical + spherical, like berry)
  2. fusiform (circumferential dilation of long segment)

Question 2

Define False aneurysm:

Answer 2

• extravascular, PULSATING hematoma

- defect in vessel wall–> blood communicates w/ intravascular space

Question 3

1 cause of aneurysms + 4 others:

Answer 3

1: ATHEROSCLEROSIS!

2. HTN (esp in thoracic aortic aneurysm)
3. Weak CT/ congenital (marfan, EDS, Vit C. deficiency)
4. Infection/ trauma/ systemic disease
5. Vasculitis

Question 4

Describe how inflammation leads to aneurysm development:

Answer 4

Inflammation–> collagen degradation»>synthesis –> ^MMPs–> destroy ECM–> weak wall–> balloon!

Question 5

Cystic Medial Degeneration:

Definition, cause, 2 consequences

Answer 5

Ischemia of media in vessel wall –> Degenerate/ Necrosis

Inner media: atherosclerosis (thick intima = less diffusion)
Outer media: HTN–> hyalinize vasa vasorum

1. SCM loss–> Less ECM synth.
2. Scarring–> lose elasticity

Question 6

What is the #1 site for Atherosclerotic Aneurysms?

Answer 6

ABDOMINAL AORTA: below renal arteries + above bifurcation (may be saccular or fusiform)

Because there are no vasa vasorum below renal arteries! Mind Blown…

Question 7

Who typically gets abdominal aortic aneurysms (3)? 
#1 Cause?

Answer 7

Men +50yoa
Smokers
ppl w/ atherosclerosis (#1 cause)

Question 8

4 Possible complications associated with abdominal aortic aneurysm:

Answer 8

1. Mural thrombus/ atheroma embolus
2. Compression/ occlusion of renal, S/I mesenteric aa.
   (via direct pressure or mural thrombus)
3. Atheromatous ulcer
4. Rupture–> fatal hemorrhage

Question 9

At what diameter do we typically surgically intervene when treating an aneurysm?

Answer 9

5-6 cm: risk = 11%/ year risk of rupture. (tx. with prosthetic graft)

Question 10

Describe the clinical presentation of an abdominal aortic aneurysm:

Answer 10

Pulsating abdominal mass w/ possible bruit on auscultation

Question 11

1 Cause thoracic aortic aneurysm + clinical symptoms/ sequelae(5)?

Answer 11

1: HTN

1. SOB–> compression of lung/ airway
2. Swallowing probs–> compression of esophagus
3. Chest Pain –> Bone erosion
4. Cardiac disease–> aortic valvular incompetence
5. RUPTURE

Question 12

What happens during an aortic dissection? Are these always associated with an aneurysm?

Answer 12

MEDICAL EMERGENCY
(Usually) Intimal tear–> Blood b/w inner 1/3 +outer 2/3 of media–> rupture–>
1. Hemorrhage into pericardial/ pleural/ peritoneal cavity OR
2. New (false) vascular channel forms due to further tear

*Not necessarily associated with aortic dilation

Question 13

4 groups of patients that get aortic dissections?

Answer 13

HTN–> men 40-60yoa (90% of cases)/// CT anomaly (Marian, EDS)–> young patients///Arterial cannulation surgery pts (iatrogenic)///Preggos/ postpartum pts

Question 14

Why are aortic dissections unusual in cases of severe atherosclerosis?

Answer 14

Medial scarring inhibits propagation of blood through wall

Question 15

Describe how HTN leads to aortic dissection

Answer 15

Similar to cystic medial degeneration

HTN–> degeneration of media–> loss of ECM–> weak wall –>tear

Question 16

2 locations of possible intimal tear that will cause aortic dissection:

Answer 16

1. Ascending aorta (most w/ in 10 cm of aortic valve)- most common
2. Transverse/ oblique
   * May extend proximally towards heart or distally*

Question 17

What is the most frequently detected pathological lesion associated with an aortic dissection?

Answer 17

Cystic medial degeneration (CMD); typically no specific underlying path.

Question 18

What is a “double barrel aorta”?

Answer 18

Aorta with a “double lumen” due to dissection and blood within media

Will see red-brown thrombus on both sides of section when aorta opened longitudinally postmortem
(Norton calls this the “turd picture”.)

Question 19

‘Type A’ Aortic dissection: Proximal or distal? Types? Prevalence/ severity?

Answer 19

Proximal lesions:

1. Ascending aorta (Debakey 1)
2. Ascending + descending aorta (Debakey 2)

*More common. More dangerous (bc they can track blood back to the heart)

Question 20

‘Type B’ Aortic Dissection: Proximal or distal? Types? Prevalence/ severity?

Answer 20

Distal lesions:
Begin distal to subclavian artery (Debakey III)
*Less common, Less dangerous

Question 21

How does an aortic dissection present clinically?

What is the current survival rate?

Answer 21

Sudden onset EXCRUCIATING PAIN:
*Begins Anterior Chest–> radiates to back–> MOVES DOWNWARD w/ progression of lesion

65-75% Survival

*May be confused with MI–KEEP IN DIFFERENTIAL!

Question 22

2 possible complications asstd. With aortic dissection:

Answer 22

1. Dissection of further vasculature:
   - great vessels of neck (stroke)
   - coronary, renal (infarction)
   - mesenteric or iliac aa’s (infarction)
2. Retrograde dissection–> Aortic valve damage–> Cardiac temponade/ Aortic insufficiency/ MI