Peripheral Vascular Disease 2 Flashcards
What is a “True Aneurysm”?
Bounded by complete but attenuated vessel wall components (Atherosclerotic, syphilitic, congenital)
What is a “False Aneurysm”?
Extravascular hematoma that communicates with intravscular space (Pseudoaneurysm, pulsating hematoma)
What is a Fusiform aneurysm?
Ovoid Swelling parallel to long axis
What is a saccular aneurysm?
Bubble-like outpouching
What is a dissecting aneurysm?
Hemorrhage into media separates vessel wall layers
What is an “arteriovenous” aneurysm?
Direct communication of artery and vein
Ascending aorta aneurysms tend to be associated with what infection?
Syphilis
Ascending and thoracic aortic aneurysms tend to be associated with what disease?
Cystic medial degneration
Abdominal aortic aneurysms tend to be associated with what disease?
Atherosclerosis
Muscular artery aneurysms tend to be associated with what disease? (E.g. coronary arteries or popliteal)
Atherosclerosis
Circle of willis aneurysms tend to be associated with what type of aneurysm?
Berry aneurysm
Sites of bacterial infections tend to be associated with what type of aneurysm?
Mycotic aneurysm
What is the definition of an abnormal aortic aneurysm?
Abnormal dilatation with diameter increased by at least 50%
What are some characteristics of abdominal aortic aneurysms?
- Always associated with severe atherosclerosis
- Male predominance
- Half patients with hypertension
- Familial clustering suggests possible genetic predisposition
- Most frequent aneurysm type
- 6% incidence in >80yr population
- Rare before age 50
What are the characteristics of the morphology of AAA?
- Severe atherosclerosis with ulcerated, calcified plaques, medial destruction, and fibrosis
- Dilatation, usually fusiform, distal to renal arteries, proximal to iliac bifurcation
- Less frequently involves common iliacs, aortic arch, descending thoracic
- Frequent mural thrombosis with potential for thromboembolism
- Symptomatic aneurysms >5-6 cm diameter
What are the clinical features of AAA?
- Clinical signs depend on location and size (Mass simulating a tumor/pulsatile, abd pain from aneurysm expansion, ureteral compression, vertebral erosion, acute ischemia of lower limb or kidneys from emboli)
- Rupture is feared and ominous complication (Pain, shock, and pulsatile abdominal mass/Rupture and massive hemorrahge, high mortality)
- Large aneurysms (>5cm) 25-40% rupture incidence within 5 years
What are the classic key features of AAA?
- Severe atherosclerosis
- Infrarenal location
- Fusiform dilatation
- Mural thrombosis
- Thromboembolism risk
- Atheroembolism risk
- Rupture
What is the definition of Aortic Dissection?
Dissection of blood in between and along the laminar planes of the media, forming a blood-filled channel within the aortic wall. Dissecting intramural hematoma, frequently ruptures, not usually associated with aneurysmal swelling
Who are some groups predisposed to aortic dissection?
- Men, 40-60 years old, antecedent HTN
- Younger patients with connective tissue disorder such as marfan syndrome
What are some features of pathogenesis of aortic dissection?
- Weakening of aortic media is common factor
- Most freqent preexisting lesion is cystic medial degeneration (CMD)
- Aging results in mild degenerative changes, focal elastin loss and medial fibrosis
- SPontaneous intimal laceration or vasovasorum hemorrhange may trigger event
What are some general key features of Marfan Syndrome?
- Tall, slender habitus
- Long thin extremities
- Arachnodactyly
- Rib/sternal abnormalities
- Hyperextensible joints
- Kyposcoliosis
- Lens dislocation, myopia
What are some cardiac/vascular anomalies associated with Marfan syndrome?
- Weakness of aortic media, leading to proximal dilatation
- High incidence of dissection and rupture
- Aortic regurgitation
- CHF
- Mitral valve prolapse
- CV disorders are most common cause of death
What is the etiology of Marfan syndrome?
- Autosomal dominant inherited connective tissue disorder
- Abnormalities of heart, aorta, skeleton, eyes, skin
- Missense mutation of fibrillin-1 (FBN1), chromosome 15q21.1
- Microfibrillar fibers critical for deposition of elastin during development
- Affected tissues show fragmented elastic fibers
What are characteristics of cystic medial degeneration?
- Most frequent preexisting histologic lesion
- Elastic tissue fragmentation
- Separation of elastic and fibromuscular elements by small “cystic” spaces filled with extracellular matrix
- No associated inflammation
- Frequently seen in Marfan syndrome
- Occasionally seen in HTN
