AAA Flashcards
Who is more likely to have AAA
Men
Diabetes is a risk factor for AAA
False
Does an open repair require follow up for endoleak risk
No
Factors that determine the risk of rupture
Size of aneurysm
Biggest risk factor for developing AAA?
Smoking
Aorta segments
Ascending aorta
Aortic arch
Descending thoracic aorta
Suprarenal abdominal aorta
Infrarenal aorta
Basic definition of aneurysm
Abnormal dilation of blood vessel by more than 50% it’s normal diameter
What structural proteins in the aorta wall decrease?
Elastin and collagen
Types of aneurysm
Saccular
Fusiform
Pseudoaneurysm
Symptoms of AAA
Asymptomatic most found incidentally
May experience back or abdominal pain or palpation of abdomen
Mortality rate of AAA
80%
How many men between 65 and 74 have AAA England
4%
Risk of rupture %?
<4cm no risk
4-4.9 = 0.5-5%
5 - 5.9 = 3 - 15%
6 - 6.9 = 10 - 20%
7 - 7.9 = 20-40%
>8 = 30 - 50%
Symptoms of AAA Rupture
Sudden intense adbo/back pain
Hypotension
Tachy
Who is invited for screening in UK?
Men over 65
Receive ultrasound scan
Referred appropriately
Referral after screening?
<3cm are discharged
3 - 4.4cm small aneurysm referred to surveillance
4.5 - 5.4cm medium and surveillance
> 5.5cm is referred to specialist vascular centre for intervention
Why 5.5cm for intervention?
Risk of rupture is higher than risk of intervention
Ultrasound requirements NAAASP
2 anterior posterior measurements of max aortic diameter
1 longitudinal and 1 transverse
Must be measured perpendicular to vessel wall
What probe is used?
Curvilinear lower resolution but higher penetration
Limitations of AAA surveillance
Bowel gas
Variation in aortic diameter with cardiac cycle
No visualisation of thoracic aorta
How to measure Aorta
Inner to inner
Leading edge to leading edge
Outer to outer
Everyone in department has to use the same method from one of the above
When to intervene AAA
> 5.5cm or symptomatic
Or if 4cm and grown by >1cm in a year
Other imaging
CT scan or MRI
