13 Aneurysmal Diseases

Question 1

remarks on aneurysms

Answer 1

an aneurysm is dilation of the arterial wall to >1.5 times its normal diameter

the wall of a true aneurysm involves all layers of the vessel

rupture is catastrophic, occurring once the stress on the vessel wall exceeds its tensile strength

Question 2

Laplace law

Answer 2

wall tension = pressure x radius

Question 3

remarks on pseudoaneurysms

Answer 3

the wall of a pseudoaneurysm consists partly of the vessel wall and partly of fibrous or other surrounding tissue

a pseudoaneurysm can develop at the site of previous vessel Catheterization and at anastomoses from prior vascular Reconstruction, Infection, or Trauma

small pseudoaneurysms may eventually spontaneously thrombose

Question 4

remarks on mycotic aneurysms vs infected aneurysms

Answer 4

MYCOTIC ANEURYSMS occur secondary to a septic embolization from valvular endocarditis

whereas INFECTED ANEURYSMS develop in an existing aneurysm after bacteremia or direct extension from a neighboring infection

Question 5

most common peripheral aneurysm

Answer 5

popliteal aneurysm
- they often coexist with contralateral popliteal aneurysms or abdominal aortic aneurysms

Question 6

visceral artery aneurysms are most common in

Answer 6

renal, splenic, and hepatic arteries
all but splenic artery aneurysms are more common in elderly men.

Question 7

mortality rate of aneurysmal rupture

Answer 7

80% mortality rate

Question 8

remarks on abdominal aortic aneurysm

Answer 8

an abdominal aortic aneurysm is defined as an aorta ≥3.0 cm in diameter
repair is considered for an aneurysm ≥5.0 cm in diameter

most patients are >60 years old

Question 9

most important environmental risk factor for abdominal aortic aneurysm

Answer 9

smoking
in addition, smoking is a major risk factor for accelerated aneurysmal growth and rupture

Question 10

most common presenting symptom with aortic aneurysm or rupture

Answer 10

BACK or ABDOMINAL PAIN
pain is classically severe and abrupt in onset, with about half of patients describing a ripping or tearing pain.

Question 11

classic triad of ruptured abdominal aortic aneurysm

Answer 11

abdominal pain
pulsatile abdominal mass
hypotension

occurs in only 1/3 of patients

Question 12

other manifestations of symptomatic abdominal aortic aneurysms

Answer 12

GI bleeding (from an aortoenteric fistula)
Extremity ischemia (from embolization of a thrombus in the aneurysm)
Shock
Sudden death

Question 13

consider an aortic aneurysm rupture in

Answer 13

a patient with abrupt back pain with syncope or shock

Question 14

iliopsoas sign

Answer 14

pain upon extension of the hip, typically with the patient lying on the opposite side
due to irritation of the psoas muscle from retroperitoneal blood

Question 15

remarks on abdominal aortic aneurysm and femoral artery

Answer 15

the presence or rupture of an abdominal aortic aneurysm typically does not alter femoral arterial pulsations

Question 16

aortoenteric fistulas most frequently involve what part of the GI tract?

Answer 16

duodenum

Question 17

imaging modality of choice for unstable ΑAA patients

Answer 17

bedside US
- a technically adequate US study has >90% sensitivity for demonstrating the presence of an aneurysm and measuring its diameter
- identifying the superior mesenteric artery allows distinguishing the aorta from the vena cava

Question 18

radiographs in aortic aneurysms

Answer 18

65% of patients with symptomatic aortic aneurysm disease have a calcified aorta, which may be more obvious on a lateral view

Plain film radiographs do not exclude the presence of abdominal aortic aneurysm or detect rupture and should be omitted for most patients

Question 19

an aortic diameter ________ excludes acute aneurysm disease

Answer 19

<3.0 cm

Question 20

best detects the anatomic details of the aneurysm and associated hemorrhage

Answer 20

CT scan with IV contrast
Scan all stable patients with suspected abdominal aneurysm disease or rupture.
For those who cannot have IV contrast, unenhanced CT can reveal aneurysm size and retroperitoneal hemorrhage

Question 21

ED interventions for symptomatic ΑAA

Answer 21

1. IV access
2. Consultation (as soon as the diagnosis is suspected)
3. Blood and fluids *(targets unclear; permissive hypotension SBP 80-90 mm Hg with intact mentation is recommended)
4. Pain control

Question 22

this can be given in the event of suspected expanding aneurysm and severe hypertension

Answer 22

esmolol, for its ability to be titrated to a target SBP of 120 mm Hg.
esmolol can be quickly stopped if the patient’s BP drops suddently.

Question 23

other remarks on aortic aneurysms

Answer 23

1. symptomatic aneurysms of any size are considered emergent.
2. All asymptomatic aortic aneurysms should be referred for follow-up.
3. ΑAA in women have a greater likelihood of rupture than in men, often at smaller sizes.

Question 24

remarks on popliteal artery aneurysm

Answer 24

>2 cm or >150% of normal caliber
may present with claudication
rupture is rare
sudden acute limb ischemia caused by thrombosis or embolization from the aneurysm is the most serious common complication

Question 25

nonaortic aneurysm where female sex is a risk factor

Answer 25

splenic artery aneurysm
- rupture has a poor prognosis because of its intraperitoneal location and nondescript presentation
- be wary of these in the third trimester of pregnancy

Question 26

remarks on hepatic artery aneurysm

Answer 26

Quincke’s triad
Hematemesis (UGIB)
Biliary colic
Jaundice

• seen when hemobilia (bleeding into biliary tract) from a leaking hepatic artery aneurysm occurs

Question 27

classic presentation of aortoenteric fistula from anastomotic aneurysms

Answer 27

severe lower GI bleeding in a patient with a history of ΑAA repair

Question 28

management of peripheral artery aneurysms

Answer 28

initial diagnostic: doppler US
if ischemia and thrombosis exist, emergent CT angiography
for patients with clinical extremity ischemia, consult immediately with a vascular surgeon to expedite repair and limb salvage
asymptomatic peripheral aneurysms are managed by a vascular consultant as an outpatient

Question 29

management of mycotic and infected aneurysms

Answer 29

these require appropriate IV antibiotics, often for prolonged periods
and consultation for surgical repair
(emergent consultation should be sought for suspected rupture)