Aneurysms Flashcards
What is the treatment threshold for a AAA
5.5 cm Males 5.0 cm females
Aneurysm vs Ectasia?
Aneurysm is focal dilatation > 50% of normal width
Ectasia is <50 %
Complications of any aneursym
Rupture (usually aortic ones)
Acute/ Chronic thrombo-embolism
Pressure-related complications
Spontaneous fistulisation
When do false-aneurysms form (aneurysms only involving adventitia and surrounding structures)
Blunt or penetrating trauma
Anastomotic sites between graft and native site
Pathophysiology Mechanisms of AA
Degenerative aneurysms: Destruction of media over time and disordered fibrous healing = weak arterial wall (classic non-specific degen. Aortic As and Peripheral As)
Infective Aneurysms: 2 mechanisms, one is direct spread into artery from adjacent source like TB lymphadenitis. The second is a blood-borne organism lodging in vasa vasorum and triggering inflammation there resulting in an A formation
Hereditary connective tissue disorders: Result in weak arterial walls with dilatation and A formation
Trauma can cause a defect in the wall and resultant pseudo-A formation
What gene is affected in Marfans Syndrome
Gene coding for Fibrillin 1 (FBN1)
Which artery’s aneurysm is related to Hypothenar-hammer syndrome
Ulna Artery A
Saccular Aneurysms are caused by?
Infective, vasculitis and trauma. They tend to complicated at smaller diameters than fusiform
Fusiform Aneuryms caused by
Degenerative and hereditary aneurysms
Where are AAAs anatomically classified?
Infra-renal (90%)
Juxta-renal
Para-renal (1 renal artery comes off Aneurysm)
Supra-renal (both renals +- mesenteric come off aneurysm)
TAAA (anywhere between L subclavian and aortic bifurcation
Pts with AAAs might have which other aneurysms concomintantly?
25-40% have iliac artery As
12-15% have descending thoracic aortic aneurysms
3-5% have peripheral ones (mostly lower limbs)
What are the numbers around:
AAA ruptured mortality:
Asymptomatic prior to rupture:
Percent that die before reaching hospital:
AAA rupture operative mortality:
Reduction in mortality with use of USS screening:
AAA ruptured mortality: 90%
Asymptomatic prior to rupture: 70%
Percent that die before reaching hospital: 75%
AAA rupture operative mortality: 50%
Reduction in mortality with use of USS screening: 50% reduction
Who gets screened
Elderly white males (>65 years)
Documented associated aneurysms
Fam hx
Indications for AAA intervention
All symptomatic or complicated AAA
Asymptomatic AAA > 5.5cm (5 in Fem)
Small AAAs on surveilance with rapid growth (more than 1cm in repeat scan)
Asymp. AAA with large iliac A (more than 3 cm)
Asymp. AAA with saccular shape more thjan 3 cm (rupture @ smaller)
Investigations for AAA
First line is a Duplex USS, can be obscured by fat and bowel gas
CTA is indicated when USS findings are inadequate and used in planning the treatment
