arterial aneurysm Flashcards
(46 cards)
What is the definition of an aneurysm?
permanent & irreversible localized dilation of a blood vessel that has atleast a 50% increase in diameter
What is the difference between an aneurysm & arterial ectasia?
aneurysm: > 50% increase in diameter
ectasia: <50% localized arterial dilatation
What are the types of aneurysms according to their wall?
- TRUE: all layers of artery are involved
- FALSE: only fibrous tissue lined from inside by endothelium
- DISSECTING: patch of intima tears & blood forcibly dissects its way between the inner & outer layer of the media
What causes a pseudoaneurysm?
partial tear of arterial wall -> extravasation of blood -> formation of hematoma surrounded by fibrin network connected to lumen
Where does a dissecting aneurysm usually occur?
thoracic & abdominal aorta
What are the 2 morphological types of aneurysms?
SACCULAR
- on one side of the vessel wall
FUSIFORM
- the whole lumen is diffusely enlarged
What arteries are more prone to saccular aneurysms?
peripheral arteries in neck & limb
Which arteries are more prone to fusiform aneurysms?
large internal arteries (aorta)
Which morphological aneurysm type is more dangerous?
saccular is more prone to rupture than fusiform but it spontaneously regresses unlike fusiform
What is the most common locations for a congenital (saccular) aneurysm?
- Circle of Willis causing subarachnoid hemorrhage
- splenic, renal & celiac arteries leading to hemorrhage into peritoneal cavity
- Ehler-Danlos syndrome & Marfan’s Syndrome
What is the most common locations for a congenital (saccular) aneurysm?
- Circle of Willis causing subarachnoid hemorrhage
- splenic, renal & celiac arteries leading to hemorrhage into peritoneal cavity
- Ehler-Danlos syndrome & Marfan’s Syndrome
What is the most common cause of acquired aneurysms & what is the commonest site it occurs in?
atheroscrelosis
INFRA-RENAL ABDOMINAL AORTA
What are the different types of acquired aneurysms?
- degenerative: atherosclerosis
- infective (mycotic): bacterial or fungal emboli may lodge in arterial wall resulting in weakness
- mechanical
What are the types of mechanically acquired aneurysms?
- post-stenotic aneurysms: in association with coarcitation, cervical rib, & popliteal artery entrapment
- traumatic aneurysms: false aneurysms due to pulsating hematoma
What is the commonest site for an aneurysm?
infra-renal abdominal aorta
what is the commonest site for a peripheral true aneurysm?
popliteal artery
What is the commonest site for a false aneurysm?
Femoral artery
What is the commonest site for a false aneurysm?
Femoral artery
What is the usual clinical picture of an aneurysm?
ASYMPTOMATIC
if symptomatic -> swelling
-> pressure manifestations
-> PAIN (impeding rupture)
-> distal ischemia
-> if popliteal artery is easily palpable consider aneurysm
if there are recurrent attacks of acute ischemia affecting distal foot with normal cardiac examination (no AF) what should be suspected?
investigate for popliteal artery aneurysms
What signs are seen upon inspection of a patient presenting with an aneurysm?
- swelling on anatomical course of a main artery
- expansile pulsations
- pulsates synchronously with heart beat
What will be felt upon palpation of an aneurysm?
- smooth cystic swelling
- moves transversely across the line of the artery but not longitudinally
- compressible
- proximal compression of artery -> shrinkage of swelling with loss of pulsations
- distal compression of artery -> increase in tension & pulsations
- palpable thrill
What will be heard upon auscultation of an aneurysm?
audible systolic bruit
What is the difference between an aneurysm & an AV fistula?
ANEURYSM AV FISTULA
- on anatomical site
- distal ischemia
- expansile pulsations
- cystic
- compressible
- palpable thrill - no hyperdynamic circulation - hyperdynamic circulation - no venous hypertension - venous hypertension - proximal compression -> decrease size - proximal compression-> decrease size & Branham's bradycardia - audible bruit is systolic - audible bruit is continuous
