Flashcards in Vascular Disease 2- Melissa (3)- Aneurysm* Deck (22):
Define True Aneurysm and list the two types:
- 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)
Define False aneurysm:
- extravascular, PULSATING hematoma
- defect in vessel wall--> blood communicates w/ intravascular space
#1 cause of aneurysms + 4 others:
2. HTN (esp in thoracic aortic aneurysm)
3. Weak CT/ congenital (marfan, EDS, Vit C. deficiency)
4. Infection/ trauma/ systemic disease
Describe how inflammation leads to aneurysm development:
Inflammation--> collagen degradation>>>synthesis --> ^MMPs--> destroy ECM--> weak wall--> balloon!
Cystic Medial Degeneration:
Definition, cause, 2 consequences
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
What is the #1 site for Atherosclerotic Aneurysms?
ABDOMINAL AORTA: below renal arteries + above bifurcation (may be saccular or fusiform)
***Because there are no vasa vasorum below renal arteries! Mind Blown...***
Who typically gets abdominal aortic aneurysms (3)?
ppl w/ atherosclerosis (#1 cause)
4 Possible complications associated with abdominal aortic aneurysm:
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
At what diameter do we typically surgically intervene when treating an aneurysm?
5-6 cm: risk = 11%/ year risk of rupture. (tx. with prosthetic graft)
Describe the clinical presentation of an abdominal aortic aneurysm:
Pulsating abdominal mass w/ possible bruit on auscultation
#1 Cause thoracic aortic aneurysm + clinical symptoms/ sequelae(5)?
1. SOB--> compression of lung/ airway
2. Swallowing probs--> compression of esophagus
3. Chest Pain --> Bone erosion
4. Cardiac disease--> aortic valvular incompetence
What happens during an aortic dissection? Are these always associated with an aneurysm?
(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
4 groups of patients that get aortic dissections?
HTN--> men 40-60yoa (90% of cases)/// CT anomaly (Marian, EDS)--> young patients///Arterial cannulation surgery pts (iatrogenic)///Preggos/ postpartum pts
Why are aortic dissections unusual in cases of severe atherosclerosis?
Medial scarring inhibits propagation of blood through wall
Describe how HTN leads to aortic dissection
*Similar to cystic medial degeneration*
HTN--> degeneration of media--> loss of ECM--> weak wall -->tear
2 locations of possible intimal tear that will cause aortic dissection:
1. Ascending aorta (most w/ in 10 cm of aortic valve)- most common
2. Transverse/ oblique
*May extend proximally towards heart or distally*
What is the most frequently detected pathological lesion associated with an aortic dissection?
Cystic medial degeneration (CMD); typically no specific underlying path.
What is a "double barrel aorta"?
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".)
'Type A' Aortic dissection: Proximal or distal? Types? Prevalence/ severity?
1. Ascending aorta (Debakey 1)
2. Ascending + descending aorta (Debakey 2)
*More common. More dangerous (bc they can track blood back to the heart)
'Type B' Aortic Dissection: Proximal or distal? Types? Prevalence/ severity?
Begin distal to subclavian artery (Debakey III)
*Less common, Less dangerous
How does an aortic dissection present clinically?
What is the current survival rate?
Sudden onset EXCRUCIATING PAIN:
*Begins Anterior Chest--> radiates to back--> MOVES DOWNWARD w/ progression of lesion
*May be confused with MI--KEEP IN DIFFERENTIAL!