abdominal aortic aneurysm

Question 1

definition
types

Answer 1

abnormal widening of blood vessel that’s 1.5 times the diameter of the proximal vessel

true: dilation of all 3 layers (intima, media, adventitia)
false: saccular cavity lined by connective tissue. the hole in the artery causes blood to leak into the cavity.

Question 2

incidence
risk factors and associated conditions
aetiology

Answer 2

higher in males >65

atherosclerosis, HTN, smoking, male and old age

ehler danlos, marfan, COPD

atherosclerotic damage to the intima -> inflammation and loss of elastin in the media -> compensatory expansion of the adventitia

Question 3

what are you afraid of with it?

symptoms?

Answer 3

1. expansion (0.2-0.8cm every year)
2. rupture (the risk is higher with larger size)
3. emboli (blue toe syndrome)

asymptomatic until incidental finding on imaging. if symptomatic: abdomen mass, pain (if rupture), pressure symptoms (early satiety, N/V)

Question 4

diagnosis?

Answer 4

US is more reliable to measure the size
Spiral CT/MRA most accurate

xray will show calcified aortic wall
angiography: not useful. shows only the lumen

Question 5

risk of rupture?

early surgery?

how to do surveillance?

indications for surgery?

Answer 5

if <5.5cm diameter then 5% risk every 5 years. if >5.5cm then 5% risk every year cumulative

early surgery shows no change in survival

US for >65 yrs every 6/12 months

indications:
size is >5.5cm even if asymptomatic
symptomatic
rupture (pt is shocked -> urgent surgery)
leak (pt is stable -> semi elective within 12hrs)
rapidly expanding

Question 6

preoperative assessment?

Answer 6

anesthesia
CXR
cardiac function: ECG, echo (EF, ventricle function)
pulmonary function test (if copd?)

some patients need cardiac revascularization before repair. improving cardiac abnormalities is associated with better outcome

Question 7

endovascular repair (EVAR) vs open?

Answer 7

EVAR: transfemoral placement of intraluminal stent graft (prosthetic graft) preferred for older patients

open: clamp proximal and distal segments to the aneurysm then place synthetic graft. careful to localize the left renal vein superiorly before clamping. preferred by younger healthy pts

Question 8

inflammatory aortic aneurysm definition, presentation, tx?

Answer 8

it’s thickening of media and adventitia (in AAA media is thin) with inflammation of duodenum, left renal vein, and ureters

present with high ESR, pain with no rupture, ureter obstruction (rare)

tx EVAR or open like AAA

Question 9

complications of AAA repair?

Answer 9

ischemic colitis, renal failure, acute limb ischemia, trash toe (emboli of debris from aorta to toes after surgery), aortic graft infection, spinal cord ischemia (thrombosis of artery of adamkiewicz)

graft infection: fever, malaise, abdomen pain, septic emboli to legs. tx with graft excision