Aneurysms and Carotid Disease Flashcards
Define aortic aneurysms.
Dilatation of all layers of the aorta, leading to an increase in diameter of over 50%.
What arteries come off of the abdominal aorta and where?
Right
- hepatic artery
- left renal artery
- superior mesenteric arteru
Left
- left gastric artery and splenic artery
- `left renal artery
- inferior mesenteric artery
Bifurcation into common iliac arteries.
What are the causes of aneurysm disease?
Degenerative disease
Connective tissue disease (e.g. Marfan’s disease)
Infection (mycotic aneurysm)
What are the risk factors for degenerative AAA disease?
Male sex, increased age, smoking, DM, hypertension, family history (prevalence of 30% in 1st degree male relatives).
What is the overall prevalence of AAA in the UK?
3%
How can AAA present?
Asymptomatically
- may present with abdominal pain and can be palpated in the abdomen or picked up in screening.
Symptomatically
Where is the most common site for AAA?
just under the renal arteries.
Which areas are particularly susceptible to atherosclerosis?
Areas of bifurcation.
Where does true aneurysm disease affect?
All three layers of the artery wall.
Where does the aorta bifurcate into the two common iliac arteries?
L4 - just above umbilicus.
What are the different criteria for screening?
Definable disease
Reasonable prevalence
Needs to be severe (aneurysms can be fatal)
Natural history that can be interrupted after intervention and that gives you time to intervene afterwards
Reliable detection, tests with suitable sensitivity
Early detection confers advantage
Treatment available
Cost Effective
Feasible
What are the different outcomes in screening related to the size of the AAA?
1 - normal aorta, discharged
2 - small AAA (3-4.4cm) will be invited for annual USS scans
3 - medium AAA (4.5-5.5cm) will be invited for 3 monthly USS scans
4 - Large AAA (>5.5cm)
What symptoms might a patient with an AAA present with?
Impending rupture -
Increasing back pain
Tender AAA
Rupture - Abdo/back/flank pain Painful pulsatile mass Haemodynamic instability (single episode or progressive) Hypoperfusion
What are some of the more unusual presentations?
Distal embolisation - in aneurysms sac there is a lot of thrombus which can break of and lodge else where Aortocaval fistula - aorta erodes into IVC Aortoenteric fistula - aorta erodes into intestines/stomach = bloody stool and death. Ureteric occlusion Duodenal obstruction (both by compression due to aorta)
What are the considerations in management of AAA?
1 - Is the AAA a size to consider repair?
2 - Is patient a candidate for repair?
3 - Is the aneurysm suitable for endovascular or open repair?
How is the size of aneurysm related to risk of rupture?
As size of AA increases risk of rupture significantly increases.
Should surgery be carried out on aneurysms sized 4-5.5cm?
No, Lancet, 1998 showed that surgery did not confer any benefit (i.e. survival) for aneurysms <5.5cm.
30 day mortality 5.8% vs risk of rupture 1% per year.
How do you determine patient fitness for open or endovascular repair?
Full history and examination Bloods ECG ECHO PFTs MPS CPEX End of bed test? Patient preference
What are the imaging techniques used for assessment of AAA and what are their pros and cons?
USS Pros - No radiation or constrast Cheap Cons - Operator dependent Inadequate for surgical planning
CTA/MRA
Pros - Quick
Not operator dependent
Necessary for surgical planning (detailed anatomy)
Cons - Constrast
Radiation
What are the three different types of treatment for AAA?
Conservative
- patient/aneurysm not fit for repair
- plan what to do in case of rupture
Endovascular repair
Open repair