Aortic Aneurysms

1
Aortic Aneurysms Common, Primarily in
the elderly, Run in families, Risk
rupture, Risk of rupture determined by
diameter, Increase in diameter determined by
hypertension
2
Aortic Dissection Sudden severe sharp chest
pain which may move Diagnosed by
transesophageal echocardiogram Treated
by lowering blood pressure and surgery
(usually)
3
Peripheral Arterial Disease Intermittent
Claudication Lost pulses, bruits, skin muscle
atrophy Diagnosed by history and physical
exam Treated by exercise
4
Acute Arterial Occlusion Usually due to emboli
from the heart Pain, pallor, paralysis,
paresthesia, pulseless-

ness Diagnosed by history and physical Treated
by anticogaulation, thrombolysis and
thrombectomy
5
Aneurysm An abnormal localized dilatation
(outpouching) of an artery, vein or heart Not
ectasia, generalized dilatation of aging True
aneurysm of an artery outpouching of all three
layers (tunica intima, media adventitia)
6
True Aneurysms of an Artery Fusiform, with
dilatation of the entire circumference the
most common Saccular bulges (pockets)
involving only a portion of the circumference
7
False Aneurysms (Pseudoaneurysms) ruptures of
the tunica intima and media and sometimes
adventitia due to trauma, infection or
surgery contained by the bulging tunica
adventitia or a even just a perivascular
thrombus and VERY UNSTABLE
8
Aortic Aneurysms Common (gt3 of those over
50) Primarily in the elderly, run in
families More common in men and in
whites Associated with hypertension (more) and
hyperlipidemia and smoking (less) More common in
the abdomen (75)
9
Aortic Aneurysms Pathogenesis Usually an
interplay between atherosclerosis and
genetically determined degeneration of the
tunica media (sometimes manifest as cystic
medial degeneration formerly called
necrosis fragmentation and loss of elastic
fibers, leaving cystic areas of myxoid matrix)
10
Aortic Aneurysms Pathogenesis Matrix
metalloproteinases capable of degrading elastic
fibers, collagen and almost all components of
wall matrix are increased in aneurysms
and tissue inhibitor of metalloproteinases is
decreased, so that spillover inflammation from
atherosclerosis may weaken the tunica media
11
Aortic Aneurysms Pathogenesis In other cases
(e.g. Marfan syndrome and Ehlers-Danlos
syndrome) genetic defects in fibrillin or
collagen weaken the tunica media Genetic defects
in matrix fibers are increasingly being
recognized in aortic aneurysms
12

• Aortic Aneurysms Less common causes
• Infective (called mycotic even when
• not fungal, which is most of the time)
• A. Syphilis (now rare, but notorious
• for aneurysms of ascending aorta)
• 2. Vasculitis
• A. Giant cell (temporal) arteritis
• B. Takayasus arteritis

13
Aortic Aneurysms Symptoms usually none, but may
cause back pain (especially if leaking) Signs
usually none, but may cause a pulsatile mass,
palpable in a thin patient Diagnosis radiology
(ultrasound good)
14

• Aortic Aneurysms Complications
• Rupture
• Major determinant diameter
• Risk for abdominal aneurysms
• 1 per year if 4 - 4.9 cm diameter
• 11 per year if 5 - 5.9 cm,
• 25 per year if gt6 cm
• Major determinant of growth hypertension

15
Aortic Aneurysms Complications 2. Mural
thrombus formation in it 3. Embolism of
atheroma or thrombus 4. Obstruction of aortic
branches 5. Aortoenteric fistula
16
Aortic Aneurysms Treatment Transabdominal
surgical repair with a prosthetic graft
previous standard, but has significant risk (5
mortality) Percutaneous deployment of
endoluminal stent graft (expandable wire mesh
frame covered by a cloth sleeve) alternative
17
Aortic Dissection Catastrophic tear of the
tunica intima letting luminal blood under high
pressure into the tunica media, where it tunnels
a second lumen Type A involves ascending aorta
/- more, more common (2/3 of them), more
serious Type B involves descending aorta alone
18
Aortic Dissection Uncommon (2000/year in the
US) Most common in late middle age More common in
men and in blacks Associated with hypertension
(gt2/3) also seen in younger patients with
Marfan syndrome or third trimester pregnancy
19
Aortic Dissection Pathogenesis Intimal tear
rarely obvious what caused it
(rarely trauma, surgery) Medial dissection
commonly associated with cystic
medial degeneration
20
Aortic Dissection Symptoms Sudden severe sharp
tearing chest pain, anterior (type A) or
between scapulae (type B), moving as dissection
progresses /- arm pain and weakness
(subclavian) altered mental status
(carotid) collapse (rupture)
21

• Aortic Dissection Complications
• Occlusion of aortic branches
• Rupture, commonly into pericardium,
• less often into left pleural cavity
• 3. Aortic valve regurgitation
• 4. Death

22

• Aortic Dissection Diagnosis
• Transesophageal echocardiogram (best)
• 2. Computerized tomography or magnetic
• resonance imaging
• 3. Chest x-ray widened mediastinum
• (neither sensitive nor specific)

23
Aortic Dissection Treatment Reduce blood
pressure to low normal with beta-blocker and
vasodilator therapy Surgery (type A) (type B
only if rupture impending, major aortic
branches compromised or dissection
progressing)
24
Peripheral Arterial Disease Chronic
atherosclerotic occlusive disease of large and
medium arteries, primarily of the legs Common
(5 of those over 70) Primarily in the
elderly More common in men Risk factors same as
for coronary disease
25
Peripheral Arterial Disease Pathophysiology Athe
rosclerotic intimal thickening /- thrombus
causing gt75 luminal stenosis Decreased blood
flow inversely proportional to length of
stenosis and blood viscosity, proportional to
radius to fourth power, so radius reduced to ½
causes flow reduced to 1/16 (Pouseilles
equation)
26
Peripheral Arterial Disease Symptoms Intermitten
t Claudication (limb pain brought on by
exercise, relieved by rest) in calf muscles
when disease in femoral or popliteal arteries,
the usual Pain at rest, ulcers severe disease
27
Peripheral Arterial Disease Signs Diminished or
lost distal pulses Bruits (swishing sounds
auscultated over lesions with
turbulent flow) Pallor (or cyanosis) Skin
atrophy, muscle atrophy Ulceration, necrosis
(gangrene)
28
Peripheral Arterial Disease Diagnosis history
physical examination (ankle/brachial blood
pressure ratio lt0.9) Treatment Exercise,
especially walking (first line) apparently
develops collaterals Cilostazol apparently
vasodilates Pentoxifylline decreases blood
viscosity Angioplasty, Surgery (bypass,
amputation)
29
Acute Arterial Occlusion Uncommon, usually due
to thromboemboli 80 from the heart (65 mural
thrombi from myocardial infarction, 10 left
atrial thrombi atrial fibrillation, mitral
stenosis, 5 dilated cardiomyopathy) 15
unidentifiable sources 5 miscellaneous sources
30
Acute Arterial Occlusion Occasionally due to
thrombosis in situ associated with
atherosclerotic plaque ulcer or rupture,
heparin-induced thrombocytopenia (HIT) or
anti-phospholipid antibody syndrome Rarely due
to paradoxical embolism via patent foramen
ovale, atrial septal defect
31
Acute Arterial Occlusion Signs, Symptoms Pain,
pallor, paralysis, paresthesia and pulselessness
(the five Ps) in the legs (70) or arms
(8) But 10 are in the brain And other sites
include intestines, kidneys and spleen
32
Acute Arterial Occlusion Diagnosis history
physical examination Treatment anticoagulation
(heparin), intra-arterial thrombolytic therapy,
catheter-based thrombectomy, surgery
(thrombectomy, bypass)
33
Aortic Aneurysms Common, Primarily in
the elderly, Run in families, Risk
rupture, Risk of rupture determined by
diameter, Increase in diameter determined by
hypertension
34
Aortic Dissection Sudden severe sharp chest
pain which may move Diagnosed by
transesophageal echocardiogram Treated
by lowering blood pressure and surgery
(usually)
35
Peripheral Arterial Disease Intermittent
Claudication Lost pulses, bruits, skin muscle
atrophy Diagnosed by history and physical
exam Treated by exercise
36
Acute Arterial Occlusion Usually due to emboli
from the heart Pain, pallor, paralysis,
paresthesia, pulseless-

ness Diagnosed by history and physical Treated
by anticogaulation, thrombolysis and
thrombectomy
37

• Sample Examination Question
• You have diagnosed a 4.5 cm abdominal
• aortic aneurysm in a 60-year-old woman.
• The most important thing to do now is
• A. Anticoagulate her
• Get her to stop smoking
• Screen her pregnant 30-year-old
• daughter for an aortic aneurysm
• D. Screen her 70-year-old brother for one
• E. Surgically repair her aorta

38

• Sample Examination Question
• Antiphospholipid antibody syndrome is
• most associated with
• Acute aortic occlusion
• Acute arterial occlusion
• Aortic aneurysm
• Aortic dissection
• Peripheral arterial disease