Blood vessel pathology Flashcards
Distinguish “elastic” and “muscular” arteries with respect to major anatomic components
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
Define and name primary complication of “cystic medial necrosis”
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
Name the most common cause of cystic medial necrosis
Aging, Hypertension
Name diseases associated with (a) Elastic Fiber and (b) Collagen synthesis defects that can manifest with cystic medial necrosis
Elastic fiber: Marfan syndrome (defect in fibrillin-1, the scaffold/sheath for elastic fibers). Collagen synthesis: Ehlers-Danlos syndrome
Define stenosis
reduced luminal diameter, can lead to ischemia/infarct
Define arteriOsclerosis and name its two subcategories
Hardening of arteries
Define the disease process of ArteriOLOsclerotic disease
Fibrosis of blood vessel wall/media in a concentric/symmetric pattern due to collagen build up. +/- glycosylation with diabetes
Define the disease process of Atherosclerotic disease
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)
Risk factors for arteriolosclerotic disease
Hypertension, diabetes
Risk factors for atherosclerotic disease
Hyperlipidemia, hypertension, diabetes, male sex, smoking
Complications of arteriolosclerotic disease
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
complications of atherosclerotic disease
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.
Labs to test for atherosclerosis risk
Lipid profile (cholesterol, LDL, HDL, triglycerides), CRP (increased CRP over time correlates with increased athero risk), Homocysteine (if very high, increased athero risk)
Define the term aneurysm
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)
Name two key disease processes involved in aneurysm formation
hypertension, atherosclerosis (also developmental such as in Marfans or Ehlers-Danlos, or post inflammatory such as in Kawasaki disease which causes coronary artery vasculitis)
Complications of aneurysm
Thrombus can form in the outpouching of aneurysm, ruptured aneurysm can result in hemorrhage (ie subarachnoid hemorrhage with cerebral swelling)
Define “pseudo-aneurysm” = “false aneurysm” and give an example
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)
Define the term dissection with respect to the aorta or other arteries
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%)
Name the key disease process underlying dissection
hypertension > cystic medial necrosis (also blunt trauma, surgery, catheterization development)
Name sites where dissecting blood may drain into and name when blood is present in these sites (hemopericardium, hemothorax, hemoperitoneum)
Blood may exit into pericardium, thorax, abdomen, back into aorta lumen. (hemopericardium, hemothorax, hemoperitoneum)
Complications of dissection
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
Name the two microscopic changes that are needed for the histologic diagnosis of vasculitis
Vessel Wall Inflammation, Vessel wall damage
List several laboratory tests that are of value in the clinical diagnosis of vasculitis
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)
Recognize the names of the major vasculitis-associated diseases
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.
How does syphylis manifest as an vascular pathology
Endartertis of vasa vasorum causes ascending aorta / aortic arch aneurysm as an element of tertiary syphilis. “tree barking” of aorta
Recognize the names of and name types of vessels comprising key vascular malformations
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
developmental component of aneurysms
thinned smooth muscle / connective tissue at bifurcations causes weakening of wall which is complicated by hypertension/atherosclerosis and has potential for rupture.
Define “hemorrhage”
Vascular breech results in loss of blood
Hypertensive hemorrhage
hemorrhage occuring in setting of hypertension
Name of a benign vascular neoplasm / developmental process
Angioma/ cavernous angioma/hemangioma: located in skin, liver, or brain
Name two malignant vascular neoplasms; name the virus associated with one of these neoplasms
Angiosarcoma of skin, liver or heart. Kaposi sarcoma is caused by HHV-8, usually seen on skin, then mucosa, lymph nodes, etc.
