Vascular Pathology

Two important congenital abnormalities:

berry aneurysms – occur in the Circle of Willis

• arteriovenous fistulas – abnormal communication
• btwn arteries and viens – looks like a web – normally in the CNS but can be
• anywhere

Endothelial cells:

monolayer which lines entire vascular system

elongated cells which form junctional complexes with neighboring cells contain Weibel-Palade bodies (storage site for von Willerbrand factor which help with clotting factors – deficiencies lead to excess bleeding)

• Smooth muscle cells:
• doesn’t regulate BP very well in big arteries but well regulated in small ones

spindle-shaped with single elongated nuclei

contractile function (mediated by actin and myosin)

migratory and proliferative capacity regulated by growth promoters and inhibitors = angiogenesis

tumors require angiogenesis so they give off hematopoetic factors that will promote BV growth

After superficial loss (not serious) of endothelial cells, neighboring endothelial cells migrate and proliferate to “fill the gap”

After severe injury, ”neointima” forms:

smooth muscle cells migrate from media to intima

intimal cells multiply

synthesis and deposition of extracellular matrix occurs which holds everything together

exaggerated healing response results in intimal thickening which can block off the lumen of the BV can produce stenosis of small to medium-sized vessels or vascular grafts

• Literally means “hardening of the arteries”Generic term for three patterns of vascular
• disease:

atherosclerosis– narrowing of a lumen of a BV by deposition of fatty material

Monckeberg medial calcific sclerosis – all of us get calcium deposited in our arteries as we get old –doesn’t cause disease really tho

arteriolosclerosis – almost like atherosclerosis but it’s only in arterioles – especially problematic in diabetics because there are arterioles in kidneys, etc. If you get this, it can lead to renal failure.

• °
• Characterized by intimal lesions called
• atheromas or fibrofatty plaques

• °
• Plaques protrude into vessel lumen, weaken
• media, and can undergo calcification and
• rupture

• °
• May be concentric (around evenly) or eccentric (more
• on one side, more unstable and can lose it’s cap easier)

• °
• Contributes to 1/2 the mortality in the Western
• world

• elastic
• arteries (aorta, carotids, and iliacs) and large and medium-sized muscular
• arteries (coronaries and popliteals)

• ° in
• childhood, but symptoms appear in adulthood

• heart,
• brain, kidneys, lower extremities, and small bowel

• myocardial infarction, stroke, aortic
• aneurysms, gangrene of legs, and ischemic encephalopathy

• ³
• raised focal plaques within the intima composed
• of a lipid core and a covering fibrous cap

• ³
• appear whitish yellow

• ³
• involves the aorta, coronaries, popliteals,
• internal carotids, and vessels of circle of Willis

• ³
• cells (smooth muscle, macrophages, and other leukocytes)

• ³
• connective tissue extracellular matrix
• (collagen, elastic fibers, and proteoglycans)

• ³
• intracellular and extracellular lipid deposits

• ³
• Calcification

• ³
• rupture/ulceration (with atheroemboli – fat embolism that broke thru and is
• floating in blood stream)

• ³
• hemorrhage

• ³
• thrombosis (stationary blood clot – if it moves it’s called a thromboemboli)

• ³
• aneurysmal dilation

• ³
• multiple yellow flat spots made of lipid-filled
• foam cells, T-lymphocytes, and extracellular lipid

• ³
• occur in all children >10 years regardless of race, sex, or
• environment

• ³
• not all fatty streaks progress to
• atherosclerotic plaques

• diabetes,
• hyperlipidemia, hypertension, and cigarette smoking

• ³
• mainly hypercholesterolemia, but also
• hypertriglyceridemia

• ³
• increased risk with high LDL

• ³
• decreased risk with high HDL

• °
• Localized dilation of a blood vessel

• °
• Occurs most commonly in the aorta (abdominal) and
• heart

• ³
• true
• aneurysms – the entire wall of the BV is bulging out – all 3 layers

• ³
• false
• aneurysms - only a part of the BV wall
• is bulging out – ex. 1 of 3

• 
• Atherosclerosis
• – most common

• ‚ cystic
• medial degeneration - degenerative disease
• of the media of the aorta and
• other arteries with loss of elastic tissue and muscle cells.

• ‚
• People with CT diseases like ehlars-danlos
• syndrome or marfan’s syndrome

• ƒ
• congenital defects like Berry aneurysms and
• atrioveneous fistulas

• „
• infection
• (mycotic aneurysms)

• …
• syphilis

• †
• trauma

• ‡
• systemic
• disease (immunologic injury)

• ‡
• Most common site of atherosclerotic aneurysms

• ‡
• Usually located below the renal arteries (below
• belly botton) but above the aortic bifurcation

• ‡
• Area very prone because of the slowing down of
• blood when branching into the common illiacs - get more deposition here

• ‡
• May be saccular (round) or fusiform (spindle
• shaped)

• ‡
• Vary in size (SIZE MATTERS)

• ‡
• Occurs in areas of severe complicated
• atherosclerosis (destroys the tunica media, weakening the aortic wall)

• ‡
• Mural (wall) thrombus frequently present (embolism common) – because blood slows
• down around this area, it allow a clot to sorta form there

• ‡
• May be accompanied by smaller fusiform or
• saccular dilations of the iliac arteries

• ‡
• If have a BIG AAA, the branches are more likely
• they have smaller ones

• ‡
• males >50
• Because you are predisposed to Atherosclerosis

• ‡
• Causes :

• ‡
• atherosclerosis

• familial/genetic predisposition (Marfan
• Syndrome)

• overproduction of certain tissue enzymes causing
• degradation of extracellular matrix

• 
• rupture with fatal hemorrhage

• 
• occlusion
• of branch vessel

• 
• embolism
• from atheroma or thrombus

• 
• impingement on adjacent structures like the
• bladder, kidneys, etc

• 
• abdominal
• mass (pulsating) – in thin people u can see their abdomen pulsating

• 
• very low for small (<4 cm) aneurysms

• 
• 11-25%
• for aneurysms >5 cm

• °
• Large aneurysms treated surgically (prosthetic
• graft put in place)

• 
• 5%
• mortality if unruptured

• 
• >50%
• mortality for emergent surgery (if it has already ruptured)

• °
• Tertiary syphilis classically involves the
• cardiovascular and nervous systems

• °
• Characteristic vascular lesion is obliterative
• endarteritis (lymphocytes and plasma cells that attack the adventitia of the
• aorta)

• 
• involves
• small blood vessels and vasa vasorum of aorta (thoracic aortitis)

• °
• Usually involves in the thoracic cavity around
• the arch of the aorta

• °
• The aneurysm can get so big and cause backflow
• into the heart and the heart can actually dialate over time (called Cor bovinum (cow
• heart) refers to a massive hypertrophy of the left
• ventricle)

• 
• may cause
• aneurysmal dilation of aorta and aortic
• annulus

• °
• Tear in the outer wall of the BV and blood
• starts flowing within the length of a BV

• °
• Dissection of blood along the laminar planes of
• the aorta

• °
• A blood-filled channel forms (dissecting intramural hematoma)

• °
• Often rupture, causing massive hemorrhage – MEDICAL EMERGENCY

• Þ
• 40 - 60 year old males with hypertension

• Þ
• patients
• with connective tissue abnormalities (such as Marfan syndrome)

• Þ
• usually begins with an intimal tear extending
• into the tunica media

• Þ
• tear is
• usually within 10 cm of the aortic valve where blood in pounding into the
• vessel wall and keeps drilling into the aorta, transverse or oblique, and 1 - 5
• cm in length with jagged edges

• °
• If it tears into the aorta, into the BV, then
• back into the lumen of the arota (as opposed to out of the aorta) then you get
• a double barreled aorta – best outcome but still need to be fixed

• Þ
• can extend proximally toward the heart as well
• as distally (as far as femorals)

• Þ
• spread
• occurs along the middle and outer thirds of the aortic wall

• °
• is rupture into a body cavity (hemopericardium
• (Can get cardiac tamoinade where blood gets into the cardiac sac and keeps the
• heart from beating efficiently), hemothorax, or hemoperitoneum)

• °
• Extension of the dissection may occur if problems in

•  aortic valve > aortic insufficiency
• 
• coronary artery > myocardial infarction

spinal arteries >transverse myelitis

• ° Most frequent cause of AD is cystic medial
• degeneration (CMD)

• ° CMD consists of elastic tissue fragmentation and
• the formation of small cystic spaces in the tunica media filled with amorphous cellular material

• ° hypertension is the major risk factor, but its
• contribution to CMD is unknown

° inherited connective tissue disorders (Marfan syndrome)

> autosomal dominant disease

>mutations noted in the fibrillin gene

• > characterized by skeletal, ocular and
• cardiovascular manifestations

• (aortic dissection, dilation of
• aortic root, and mitral valve prolapse)

• proximal
• lesions involving the ascending aorta are most
• dangerous – b4 subclavian artery

lesions distal to the subclavian artery

• Þ
• onset of
• excrutiating RADIATING chest pain, to the shoulder, radiating to back, moving
• downward as dissection progresses

• Þ
• may be
• mistaken for myocardial infarction – you have to rule out a MI b4 you know that
• it is an AD – rule out by enzyme test (troponin)

• °
• imaging studies – Radiograph won’t help, CT or
• MRI prob will because they will show the abnormal accumulation of blood

• °
• once invariably fatal

• °
• now
• treatments available including placation (sewing it up) of aortic wall and
• antihypertensive therapy so that they won’t get another dissection

• °
• survival
• rate of 65-75%

• °
• inflammation of vessel wall

• °
• 2 types or mechanisms:

• Þ
• immune-mediated* (immune complexes and
• autoantibodies attack the vessels)

• Þ
• direct
• invasion of vessel wall by infectious agent

• °
• c-ANCA (cytoplasmic antineutrophilic cytoplasmic antibodies),
• target antigen PR-3, seen in Wegener granulomatosus
• ° Fluorescense around the nucleus in the cytoplasm

• °
• p-ANCA (perinuclear antineutrophilic cytoplasmic antibodies),
• targets myeloperoxidase, seen in leukocytoclastic vasculitis

• °
• either ANCA may occur in small vessel vasculitis

• °
• acute and chronic, often granulomatous,
• inflammation of medium-sized and small arteries

• °
• affects principally the arteries of the head
• (particularly the temporal arteries)

• °
• may affect aortic arch (giant cell aortitis)

• °
• affects patients >50, usually with facial
• pain in the distribution of the temporal artery

• involving
• anti-inflammatory agents is very effective

• °
• depends on biopsy (requires 2 - 3 cm segment of
• artery)

• °
• lesions are segmental and may be missed in
• biopsy

• °
• presumptive diagnosis and prompt treatment may
• be necessary because it can cause blindness associated

• °
• Affects arterioles, capillaries, and venules

• °
• All lesions tend to be same age

• °
• ANCA present in majority of cases

• °
• May affect every organ system, but in many cases
• is limited to the skin (Cutaneous Microscopic Polyangitis )

• °
• hemoptysis (couphing up blood), hematuria,
• proteinuria (affecting the kidney), GI bleeding, muscle pain

• °
• may be related to drugs,microorganisms,
• proteins, or tumor antigens

• °
• Histologically, segmental fibrinoid necrosis (vessel
• wall gets pink and dead LOOKING) and fragmented neutrophils (leukocytoclasia –
• break down of leukocytes – so disease can be called leukocytoclastic vasculitis
• = microscopic polyangitis)

• °
• Patients respond well to removal of offending
• agent

• 
• acute necrotizing granulomas of the upper
• respiratory tract

• 
• focal
• necrotizing granulomatous vasculitis

• ƒ
• renal
• disease (crescentic glomerulitis)

• ƒ
• Males affected more often than females

Average age of 40

• ƒ
• Immune
• complexes in vessel walls and response to immunosuppressive agents suggest
• immunologic mechanism
• ƒ
• 90% of cases have c-ANCA in serum

• ƒ
• Segmental, thrombosing, acute and chronic
• inflammation of medium-sized and small arteries

• ƒ
• Occurs
• almost exclusively in cigarette smokers

• ƒ
• Leads to vascular insufficiency

• ƒ
• superficial nodular phlebitis – formation of
• blood clots in veins

• ƒ
• cold
• sensitivity bc of constriction of bv

• ƒ
• pain of
• the instep caused by exercise

• ƒ
• Chronic ulceration of extremities may lead to
• gangrene

• early stages, cessation of smoking may relieve
• symptoms

• ƒ
• direct invasion by bacteria or fungus
• (aspergillosis and mucormycosis)

• ƒ
• lodging
• of septic embolus – cruse ship for bacteria

• ƒ
• seeding
• from bacteremia

• ƒ
• Infection may weaken vascular wall and cause a
• mycotic (infectious) aneurysm

• °
• Paroxysmal pallor and cyanosis of the feet or
• hands, rarely nose, earlobes, or lips

• °
• Caused by vasoconstriction of local small
• arteries or arterioles

• ±
• Primary (young females, exaggerated response to
• cold or emotion)

• ±
• Secondary (systemic lupus erythematosus,
• systemic sclerosis aka scleroderma, atherosclerosis, Buerger disease) – rule these
• out and you have the primary cause

• °
• Abnormally dilated veins produced by prolonged
• increased intraluminal pressure and loss of support of vessel wall (caused by
• chronic standing)

• °
• Superficial veins of leg most common site

• °
• May thrombose (rarely embolize if superficially,
• unlike deep vein thrombosis)

• °
• Symptoms: pain, persistent edema, stasis
• dermatitis, and ulceration

• °
• Seen frequently in obese females >50 y/o

• °
• occur in patients with cirrhosis (from alcoholis
• or hepatitis B or C) and portal hypertension

• °
• rupture may cause massive hemorrhage

• °
• dilation of anorectal venous plexus

• °
• caused by pelvic congestion

• °
• cardiac
• failure

• °
• neoplasia

• °
• pregnancy

• °
• obesity

• °
• post-operative state

• °
• immobilization
• (prolonged bed rest)

• 
• deep leg
• veins (90% of cases)

• 
• periprostatic venous plexus

• 
• pelvic
• veins

• 
• large
• veins of skull and venous sinuses

• …
• portal
• vein

• …
• Early stages à
• few or no symptoms (edema, cyanosis, dilated superficial veins, heat,
• tenderness, redness, pain, swelling)
• …
• Embolism may be first manifestation

• …
• Neoplasms such as adenocarcinoma of the
• pancreas, colon, or lung initiate hypercoagulability

• … Venous thromboses appear
• spontaneously, disappear, and are followed by thromboses in other veins can be
• an early sign of a adenocarcinoma

• …
• Obstruction of SVC producing cyanosis (blue
• color) and marked dilation of veins of head, neck, and arms

• …
• Caused by neoplasms that compress or invade the
• SVC (most commonly primary bronchogenic carcinoma or mediastinal lymphoma)

• …
• Rarely caused by aortic aneurysms

• …
• Compression of the IVC with resulting edema of
• lower extremities, distention of veins of lower abdomen, and massive
• proteinuria when the renal vein is involved

• …
• Caused by neoplasms that compress or penetrate
• the IVC (particularly hepatocellular carcinoma and renal cell carcinoma) or
• thrombus from the femoral or iliac veins

• …
• acute inflammatory involvement of lymphatic
• channels by bacterial infections (most common agents are the group A b - hemolytic streptococci)

may lead to acute lymphadenitis

• …
• Primary (congenital or familial) disorders

• …
• Secondary (acquired) disorders
• usually associated with inflammation or cancer

• …
• Balloon angioplasty (dilation of atheromatous
• stenosis by a balloon catheter)

• …
• Stent placement (inserting metallic mesh tubes
• to hold artery open)

• …
• Vascular replacement
• synthetic grafts may be used in large or small vessels, but perform best in large
• diameters

• …
• autologous grafts (saphenous or internal
• mammary artery) are patients’ native vessels transplanted to a different site –
• usually the best and last the longest

• °
• Uses autologous saphenous vein or internal
• mammary artery to bypass stenotic vessels

• ±
• 50% of saphenous grafts are patent at 10 years

• ±
• 90% of IMA grafts are patent at 10 years (would
• rather use this for the graft but it’s much shorter and might not be long
• enough)

• ±
• Graft failure is due to thrombosis, intimal
• thickening, and atherosclerosis