Aneurysms and Peripheral Vascular Disease Flashcards
What is an aneurysm?
abnormal localized dilation (outpouching) of an artery, vein or heart
What is a pseudoaneurysm? What can cause it?
contained ruptures of the tunica intima and media and (sometimes) adventitia of an artery. Can be due to trauma, infection, or surgery.
What is the difference between a saccular and fusiform aneurysm?
A saccular aneurysm is a discrete outpouching that usually contains a thrombus. A fusiform aneurysm is a circumferential dilation of a blood vessel.
What is an aortic dissection?
a catastrophic tear of the tunica intima letting luminal blood under high pressure into the tunica media–where it tunnels a second lumen
What is a type A dissection?
involving ascending aorta (proximal lesion)- surgical emergency! More common 2/3 of cases
What is a type B dissection?
beginning beyond the subclavian artery (distal lesion affecting ONLY the descending aorta)- not a surgical emergency
What is ectasia?
generalized dilation usually associated with aging
What is the biggest difference between ectasia and an aneurysm?
NOT localized—whole things is ballooned out so you have less of a problem because no turbulent flow!
Are false aneurysms stable?
NO they are unstable and prone to bursting (losing their containment)
Who gets aortic aneurysms?
elderly white males who smoke, have HTN and have hyperlipidemia
Where is the most common place for aortic aneurysms?
abdomen (75%)
Describe the pathogenesis of aneurysms.
Increased matrix metalloproteinases (which remodel arteries) and decreased tissue inhibitors of MMPs will allow spillover inflammation from atherosclerosis to injure and weaken the tunica media
Is inflammation always related to aneurysms?
NO, genetic defects in fibrillin (Marfan syndrome) or collagen (Ehlers-Danlos syndrome) can weaken the tunica media and presdispose to aneurysms
What markers of inflammation can usually be found in the blood of someone who is forming an aneurysm?
CRP and IL-6
Other than genetic disorders and spillover inflammation from atherosclerosis, what can cause aneurysms?
infection (called “mycotic” even when not fungal, which is most of the time)
vasculitis (e.g. giant cell arteritis)
What is cystic medial degeneration?
ischemic changes in outer media leading to smooth muscle cell loss and “degenerative changes” in the aorta (fibrosis, inadequate ECM synthesis, and accumulation of amorphous proteoglycans)
What symptoms MAY you see in someone with aortic aneurysms?
back pain (if leaking) Pulsatile mass (palpable in thin patients)
What is the best way to diagnose an aortic aneurysm?
ultrasound
What is the major complication of aortic aneurysms?
rupture
What is the major determinant of aneurysm rupture?
diameter (over 5 cm significantly increases risk of rupture)
How/when do you treat an aortic aneurysm? Why?
when >5 cm in diameter, surgically managed (with endoluminal stent graft) because 5% survival if managed, 50% mortality if rupture!
What is the major factor in the rate of aneurysm growth?
blood pressure (hypertension accelerates aneurysm growth)
List other complications of aortic aneurysms?
Mural thrombus formation (universal)
Embolism from the atheroma or thrombus
Obstruction of aortic branches
Aortoenteric fistula (aorta erodes passage into the intestine
True or false: aortic aneurysms are familial.
TRUE (if you know of a person with AAA, you probably want to screen siblings)
True or false: aortic dissections are very common.
FALSE- they are uncommon- only around 2,000 in the US every year
Who gets aortic dissections?
late middle aged black men who have hypertension (2/3 of cases) OR younger patients with Marfan syndrome OR in late pregnancy
Aortic dissections usually start with what change in the vessel?
intimal tear
Motor vehicle accidents with deceleration can cause an intimal tear at what structure?
ligamentum arteriosum
How might rupture of vasa vasorum lead to a dissection?
rupture of vasa vasorum may cause hemorrhage in the wall and dissection of this hemorrhage into the lumen can cause the intimal tear needed to get the dissection started
What is the primary symptom of a type A dissection?
sharp, anterior tearing chest pain
What is the primary symptom of a type B dissection?
sharp, tearing chest pain felt between the scapula
What symptoms can accompany the tearing pain of a dissection?
arm pain or weakness (with subclavian artery compromised), altered mental status (if carotid involved), or collapse (if it ruptures)
What are the complications of dissection?
1) rupture (into pericardium)
2) occlusion of aortic branches
3) aortic valve regurgitation
4) death
How do you diagnose a dissection?
Transesophageal echocardiogram
Computerized tomography
OR MRI
How do you treat a type A dissection?
beta-blockers and vasodilators (to treat HTN)
surgery
What are the cases where a type B dissection would require surgery?
if rupture is impending
if major aortic branches are compromised
if dissection is progressing
What is peripheral arterial disease (PAD)?
chronic atherosclerotic occlusive disease of large and medium arteries–primarily of the legs
True or false: PAD is common.
TRUE it is in 20% of those over 70 y/o
What is most likely the biggest factor in flow through a vessel?
radius of the vessel (atherosclerotic narrowing can decrease radius and reduce flow drastically)
What is intermittent claudication?
ischemic pain of the periphery–usually the legs (calves) that can be brought on by exertion and relieved by rest
What are indicators of severe PAD?
pain at rest and ulcers
What are some signs of PAD?
diminished or lost distal pulses bruits pallor skin atrophy muscle atrophy ulcerations gangrene (necrosis)
How do you make a PAD diagnosis?
history and physical exam
ABR
How do you measure ankle/brachial ratio?
measure blood pressure in the arm and lower leg of a supine patient
What is a diagnostic ankle/brachial ratio for PAD?
an ABS less than .9 requires no further diagnostic tests for diagnosis
What is the first line of treatment for PAD?
exercise (walking) in order to develop collaterals
What are the other treatment options for PAD?
cilostazol (vasodilates)
pentoxifylline (decrease blood viscosity)
angioplasty
surgery (bypass or amputation)
What is an acute arterial occlusion?
uncommon blockage of arteries due to thromboemboli
Where do the thromboemboli in acute arterial occlusion usually start?
80% from heart
- 65% from mural thrombi after MI
- 10% from left atrial thrombi during a-fib
- 5% from mural thrombi from dilated cardiomyopathy
What are the other causes of acute arterial occlusion?
thrombosis in situ associated with plaque ulcer/rupture, HIT, or anti-phospholipid antibody syndrome
OR
Rare paradoxical embolism through a patent foramen ovale or ASD
What are the signs/symptoms of acute arterial occlusion?
5 P’s: pain, pallor, paralysis, paresthesia, pulselessness in legs (70%) or arms (8%) or brain (10%)
How do you diagnose acute arterial occlusion?
physical exam
How do you treat acute arterial occlusion?
Anticoagulation (heparin)
Intra-arterial thrombolytic therapy
Catheter-based thrombectomy
Surgery (thrombectomy/bypass)
True or false: acute arterial occlusion is a surgical emergency.
TRUE
What is Buerger Disease?
thromboangiitis obliterans–a chronic thrombosing inflammatory disease of small and medium arteries and veins of arms and legs
Buerger disease is 100% associated with what?
smoking
Buerger disease is most common in what country?
10-100 times more common in Asia than US
When does Buerger disease usually start?
onset is typically in 20s
What occurs in the “acute phase” of Buerger disease?
Segmental transmural acute inflammation with granulomas/giant cells (but NO necrosis)
What is characteristic of acute phase Buerger disease?
thromboses with “microabscesses”
What occurs in the “chronic phase” of Buerger disease?
nonspecific organization and recanalizaiton of thrombus with neovascularization and fibrosis
What are the signs and symptoms of Buerger disease?
instep claudicaiton
cold feet
Raynaud’s phenomenon
migrating superficial nodular thrombophlebitis
What are the complications of Buerger disease?
gangrene, autoamputation of finges and toes
How do you diagnose Buerger disease?
history and physical exam
What does an angiogram of Buerger disease show?
stenosis with corkscrew collaterals
How do you “treat” Buerger disease?
cessation of smoking
amputation
