Blood vessel pathology

Question 1

Distinguish “elastic” and “muscular” arteries with respect to major anatomic components

Answer 1

Elastic: accommodates / dampens pulsatile blood flow (ie. Aorta, coronary arteries). Thin walled, intima proliferation with thickening, scant smooth muscle in media with considerable elastic tissue. Muscular: regulate blood flow to organ (major branches off of aorta). Intial is thick and media is thick with abundant smooth muscle and scant fibrous CT
Elastic: accommodates / dampens pulsatile blood flow (ie. Aorta, coronary arteries). Thin walled, intima proliferation with thickening, scant smooth muscle in media with considerable elastic tissue. Muscular: regulate blood flow to organ (major branches off of aorta). Intial is thick and media is thick with abundant smooth muscle and scant fibrous CT

Question 2

Define and name primary complication of “cystic medial necrosis”

Answer 2

Definition: Degeneration that results in fragmentation of elastic fibers in the media of aorta, with normal layering of elastic fibers around it. Primary complication is aortic dissection

Question 3

Name the most common cause of cystic medial necrosis

Answer 3

Aging, Hypertension

Question 4

Name diseases associated with (a) Elastic Fiber and (b) Collagen synthesis defects that can manifest with cystic medial necrosis

Answer 4

Elastic fiber: Marfan syndrome (defect in fibrillin-1, the scaffold/sheath for elastic fibers). Collagen synthesis: Ehlers-Danlos syndrome

Question 5

Define stenosis

Answer 5

reduced luminal diameter, can lead to ischemia/infarct

Question 6

Define arteriOsclerosis and name its two subcategories

Answer 6

Hardening of arteries

Question 7

Define the disease process of ArteriOLOsclerotic disease

Answer 7

Fibrosis of blood vessel wall/media in a concentric/symmetric pattern due to collagen build up. +/- glycosylation with diabetes

Question 8

Define the disease process of Atherosclerotic disease

Answer 8

Abnormal deposits/infiltrates in the intimal region (+/- media) of blood vessel, usually asymmetrical in an eccentric pattern. Can be from lipids, and/or repair processes (collagen deposition by fibroblasts or neovascularization, inflammatory cells and calcification)

Question 9

Risk factors for arteriolosclerotic disease

Answer 9

Hypertension, diabetes

Question 10

Risk factors for atherosclerotic disease

Answer 10

Hyperlipidemia, hypertension, diabetes, male sex, smoking

Question 11

Complications of arteriolosclerotic disease

Answer 11

Reduced contractility of vessels, luminal compromise leading to ischemic risk.ie. In vessels of the brain, a cavitary defect can occur with tissue necrosis and development of a gliosis (brain scar) around the lesion (chronic infarct). Usually occurs in brain, eyes, kidneys and nerves

Question 12

complications of atherosclerotic disease

Answer 12

Luminal narrowing / Stenosis leading to ischemia/infarct, Thrombus formation on surface of damaged vessel leading to further narrowing, Embolization (thrombus or atherosclerotic debris) leading to transient ischemic attacks vs. infarcts, aneurysmal dilation, or rupture leading to hemorrhage. Usually occurs in coronary arteries, aorta and major branches of aorta.

Question 13

Labs to test for atherosclerosis risk

Answer 13

Lipid profile (cholesterol, LDL, HDL, triglycerides), CRP (increased CRP over time correlates with increased athero risk), Homocysteine (if very high, increased athero risk)

Question 14

Define the term aneurysm

Answer 14

Dilation of luminal diameter with potential for rupture. True aneurysms are saccular (a pouch-like dilation of a portion of vessel at bifurcation of vessel or in an area of asymmetric damage such as atherosclerosis) or fusiform (uniform/symmetric dilation of vessel lumen, such as in aorta)

Question 15

Name two key disease processes involved in aneurysm formation

Answer 15

hypertension, atherosclerosis (also developmental such as in Marfans or Ehlers-Danlos, or post inflammatory such as in Kawasaki disease which causes coronary artery vasculitis)

Question 16

Complications of aneurysm

Answer 16

Thrombus can form in the outpouching of aneurysm, ruptured aneurysm can result in hemorrhage (ie subarachnoid hemorrhage with cerebral swelling)

Question 17

Define “pseudo-aneurysm” = “false aneurysm” and give an example

Answer 17

Accumulation of blood or inflammation associated with wall of artery where luminal diameter is not increased (often is reduced in size). Exmaples: femoral artery puncture (under systemic pressure, blood dissects into wall of blood vessel) or fungal infection with invasion and weakening of vessel wall (mycotic aneurysm)

Question 18

Define the term dissection with respect to the aorta or other arteries

Answer 18

Blood enters arterial wall by dissecting along connective tissue planes in media. Type A are located in Ascending Aorta/ arch. Type B are located in in branches off of or below the aortic arch. DeBakey I is Arch only (10%), DeBakey II is Ascending only (65%), DeBakey III is below Arch/branch (5%)

Question 19

Name the key disease process underlying dissection

Answer 19

hypertension > cystic medial necrosis (also blunt trauma, surgery, catheterization development)

Question 20

Name sites where dissecting blood may drain into and name when blood is present in these sites (hemopericardium, hemothorax, hemoperitoneum)

Answer 20

Blood may exit into pericardium, thorax, abdomen, back into aorta lumen. (hemopericardium, hemothorax, hemoperitoneum)

Question 21

Complications of dissection

Answer 21

Rupture can cause severe pain (Anterior chest for type A, Between scapula for type B), pulse abnormalities, cardiac tamponade if periaortic rupture into pericardium, Hypovolemic shock if abdominal or thoracic rupture. Occlusion of vessels can cause stroke, MI, etc

Question 22

Name the two microscopic changes that are needed for the histologic diagnosis of vasculitis

Answer 22

Vessel Wall Inflammation, Vessel wall damage

Question 23

List several laboratory tests that are of value in the clinical diagnosis of vasculitis

Answer 23

Measure markers of inflammation +/- autoimmune:  - Rheumatologic screen (etiologically non-specific -- except                      ~ANCA):  - ANA, ESR (Erythrocyte Sedimentation Rate), CRP (C-Reactive Protein), ANCA (Anti-Neutrophil                             Cytoplasmic Protein, P-ANCA and C-ANCA)
Hepatitis screen: B, C
Eosinophil count (Churg-Strauss syndrome)

Question 24

Recognize the names of the major vasculitis-associated diseases

Answer 24

Giant cell arteritis and Takayasu arteritis (granulomatous in large vessels), Polyarteritis nodosa (immune complex mediated in medium vessels), Kawasaki disease (anti-endothelial cell Abs in medium vessels), microscopic polyangitis(no asthma or granulomas), Wegener granulomatosis (granulomas) and Chrug-Strauss syndrome(Granulmoas), SLE vasculitis, Henoch-schonlein purpura (IgA), cryoglobulin vasculitis, goodpasture disease.

Question 25

How does syphylis manifest as an vascular pathology

Answer 25

Endartertis of vasa vasorum causes ascending aorta / aortic arch aneurysm as an element of tertiary syphilis. “tree barking” of aorta

Question 26

Recognize the names of and name types of vessels comprising key vascular malformations

Answer 26

Arteriovenous: mixed arteries and veins with potential for arterial to venous shunt. Cavernous angioma/hemangioma: aterial or arteriole. Telangiectasia: small vessels, capillaries. Lympangioima: lymphatic channels. Sturge-Weber: venous malformation with port wine stains and mineralization/seizures of brain

Question 27

developmental component of aneurysms

Answer 27

thinned smooth muscle / connective tissue at bifurcations causes weakening of wall which is complicated by hypertension/atherosclerosis and has potential for rupture.

Question 28

Define “hemorrhage”

Answer 28

Vascular breech results in loss of blood

Question 29

Hypertensive hemorrhage

Answer 29

hemorrhage occuring in setting of hypertension

Question 30

Name of a benign vascular neoplasm / developmental process

Answer 30

Angioma/ cavernous angioma/hemangioma: located in skin, liver, or brain

Question 31

Name two malignant vascular neoplasms; name the virus associated with one of these neoplasms

Answer 31

Angiosarcoma of skin, liver or heart. Kaposi sarcoma is caused by HHV-8, usually seen on skin, then mucosa, lymph nodes, etc.