peripheral vascular disease Flashcards
Aneurysm (congenital or Acquired)
Localized dilatation of BVs (aorta or heart
Types: True (involves all three layers of wall), False or pseudo aneurysms- wall defect leading to extravascular hematoma
Arterial dissection- blood enters the wall of the artery
Pathogenesis of aneurysms
Factors affecting collagen structure or function: inadequate or abnormal syntheses of collagen (marfans - defective fibrillin synthesis, no scaffolding of elastic tissue, results in cystic medial necrosis of aorta, leads to aneurysm formation and aortic dissection
Ehlers Danlos syndrome: one variant has defective type 3 collagen, leads to aneurysm formation
Excessive CT degradation (increased MMPs or decreased TIMPs that inhibit the MMP), inflammation (atherosclerosis) polymorphisms of MMP or TIMP may predispose to aneurysm formation
Loss of smooth muscle cells–thickening of intima (due to atherosclerosis)- leads to ischemia or inner media, systemic hypertension, (narrows vasa vasorum–ishcemia of outer media), morphology results in cystic medial degeneration
Specific underlying causes of aneurysms
Common: atherosclerosis- abdominal aorta
Hypertension- ascending aorta
Uncommon- congenital defects (berry aneurysm- bifurcation of cerebral areteris, subarachnoid hemorrhage) infections (mycotic aneurysm- septic emboli, direct extension, direct infection via circulating organisms, syphillis (treponema pallidum) trauma- AV fistula aneurysm, vasculitis, igG4 disease, genetic defects in collagen (marfans and ehlers Danlos
Aortic aneurysms
Locations- abdominal aortic aneurysm (AAA) most common location, below renal arteries and above bifurcation
Arch of aorta, thoracic aorta, and iliac arteries less common
PAthogenesis/etilogy- men smokers, atherosclerosis
Morphology- up to 15 cm in diameter, thinning and destruction of media, mural thrombus, saccular or fusiform, variants (inflammatory- unknown etiologu, mycotic (secondary to infection (salmonella)
Abdominal aortic aneurysm clinical course
more common in men over 50, present as pulsatile abdominal mass, complications (rupture into peritoneum, retroperitoneum). vascular obstruction (renal mesenteric spinal arteries, embolism of atheroma or mural thrombus to kidneys or lower extremities, impingement of ureters
Aggressive management for large 5 cm aneurysms risk of rupture is directly proportional to size
Thoracic aortic aneurysms
Hypertension, Marfans syndrome, Syphilis (tertiary)
Clinical features: Mediastinum encroachment, tracheal compression, esophageal compression, bone erosion cough due to irritation of recurrent laryngeal nerve
Cardiac symptoms: heart failure due to aortic valve insufficiency
Aortic rupture
aortic dissection
Blood between and along laminar planes of media- causes a blood-filled channel that easily ruptures
Pathogenesis/etilogy- HTN (40-60 yrs of age), >90% of cases
CT abnormalities (younger ages): in association with Marfans syndrome or Ehlers-Danlos syndrome
Ascending aorta most commonly involved
Rare causes: post procedural- arterial cannulation, pregnancy
Morphology of Aortic dissection
intimal tear within Cm of aortic valve, dissection plane between middle and outer third of wall , in media and
Dissection usually extends anterograde, usually ruptures outs, may reenter and form a double barreled lumen
In HTN: vasa vasorum hyaline arteriolosclerosis, media loss of smooth muscle cells
Pre existing pathology of cystic medial degeneration in patients with CT disorders.
Aortic dissection: clinical course
dependent on level of aorta involved, sharp paon of anterior chest, uneven pulses and widened mediastinum
Type a- both sides, type b one side
Classic clinical symptoms- sudden onset of tearing or stabbing pain in anterior chest radiating to back
Complications of aortic dissection
Hemopericardium occurs when blood dissects thru media, proximally
May also rupture into pleural or peritoneal cavities
Vasculitis
inflammation of vessel walls, may affect any sized vessel, pathogenesis (immune-mediated processes, infectious origin, unknown)
path of immune mediated vasculitis
Immune complex mediated: SLE (DNA anti DNA complexes), hypersensitivity to drugs, viral infections (HBsAg-antiHBSsAg)
ANCA associated: auto antibodies against enzymes in granules of PMNs Ab titers mirror clinical severity
2 main patterns: Antiproteinase-3 (PR3-ANCA)–granulomatosis with polyangiitis and Chirg-Strauss syndrome (
Vasculitis
infectious (direct invasion- syphilis, aspergillus, mucormycosis)
Indirect via immune mechanisms triggering cross-reactivity
Unknown Giant cell arteritis, takayasu arteritis, polyarteritis nodosa
Giant cell (temporal) arteritis
Most common form of systemic vasculitis in adults–affects aorta and its major branches, especially temporal artery, ophalmic, and vertebral arteries
Pathogenesis: uncertain, T cell mediated driven by antigen
> 50y, often with painful superficial temporal artery, diplopia, visual loss, headache
increased ESR, diagnosis (biopsy) treat with steroids
Gross: nodular thickenining of artery with narrowed lumen, patchy (discontinuous segments affected, biopsy requires 2-3 cm
histo: granulomatous inflammation of inner half of media around internal elastic lamina (destroys internal elastic lamina), multinucleated giant cells
takyayasu arteritis
pulseless disease (upper extremities, ocular disturbances, jap fem under 40
granulomatous inflammation of aortic arch and its branches
pulm arteries involve half of time, coronary and renal arteries sometimes involved
pathogenesis-autoimmune etiology, histo (lymphocytes giant cells, collagenous fibrosis)
polyarteritis nodosa classic
systemic segmental transmural necrotizing inflammation of small/med sized muscular arteries
Renal and visceral arteris affected, usually spares lungs
Focal, random, episodic, all stages of inflammation and fibrosis co exist, aneurysms, young adults (30% Hep B ag), no ANCA
Acute chronic subacute or remittent course
90% remission or cure (corticosteroids, cyclophosphamide)
Classic presentation: Rapidly accelerating HTN, abdominal pain, bloody stools, peripheral neuritis
kawasaki syndrome
Endemic in Japan
Large med and small arteries, often coronaries with aneurysm formation
With mucocutaneous lymph node syndrom (mucous membrane inflammation, enlarged lymph nodes)
80% are under 4 yrs, leading cause of acquired heart disease in kids in japan
Histo: necrosis and inflammation, aneurysms, resembles polyarteritis nodosa
Etiology: Ab and viral trigger
Microscopic polyangiitis (leukocytoclastic vasculitis
Arterioles, capillaries, venules
Skin mucous membranes, lungs, brain, heart, GIT , kidneys, muscles (necrotizing glomerulonephriteis 90%, and pulm capillaritis)
MPO ANCA in 70%
Immunologic rxn to Ag (drug, Strp, tumor proteins)
histo: fibrinoid necrosis, neutrophils, nucleat dust
Major clinical features are dependent on vascular bed involved: hemoptysis, hematuria, proteinuria, abdominal pain or bleeding muscle pain or bleeding and cutaneous purpura
Granulomatosis with polyangiitis
Necrotizing vasculitis (granulomas of lung ndor upper respiratory tract –ear, nose, sinuses, throat)
Vasculitis of small to medium sized vessels in lungs and upper respiratory tract
Glomerulonephritis
PR3-ANCA present in 95%, cell mediated hypersensitivity responses against inhaled infections or environmental Ag
M>F (40 yrs of age) , Symptoms (pneumonitis, sinusitis, nasopharyngeal ulceration, renal
Churg Strauss Syndrome
Small vessel vasculitis associated with (asthma, allergic rhitis, lung infiltrates, peripheral eosinophilia and infiltration of vessels by eosinophils, extravascular necrotizing granulomas)
Clinical symptoms: palpable purpura, GI bleed, Renal impairment, cardiomyopathy
Thromboangiitis obliterans beurgrers disease
inflammation and thrombosis of med to small musc arteries and secondarily the veins and nerves, stibial and radial arteries, smokers, painful ischemic disease, gangrene of limbs requiring amputation, etiology unknown
Raynauds phenomenon
Paroxysmal pallor or cyanosis of fingers, toes, nose, or ears
primary- recurrent vasospasm , young healthy women,
Sec- arterial insufficiency- narrowing SLE SS atherosclerosis bergerus disease
Varicose veins
Varicosity- venous dilation due to elevated pressure and or weakend vessel wall (dilation lead to valvular incompetence, edema, pain, thrombosis, stasis dermatitis and ulcers
Obesisty, pregnancy
Superficial leg and veins (low risk of embolism)
Esophageal varices- caused by portal HTN form cirrhosis or portal vein thrombosis, susceptible to rupture and bleeding
Hemorrhoids (anorectal veins, from preg and strain)
