Abdominal aortic aneurysm Flashcards
(38 cards)
What age does AAA usually occur in?
-60-70 years
What is the definition of AAA?
- Localised dilation of all 3 layers(intima,media and adventitia) to more than 50% of its original size
What are the causes/risk factors for AAA?
- Old age
- Family history
- Smoking hx
- Hypercholesteraemia and arterial hypertension
- Atherosclerosis
What is the pathophysiology of AAA?
- inflammation and degeneration of connective tissue by proteloytic enzymes
- mechanical stress(high blood pressure )can cause further dilation and rupture
Where does the AAA usually develop?
- infrarenal-95%
- juxtrarenal-5%
What are the clinical features of a patient with AAA?
-Back pain
-mostly asymptomatic
-trash feet(gangrenous foot)
-
How do we diagnose AAA?
- Ultrasound-best initial and confirmatory test
- CT-determines AAA rupture
What is the treatment for an AAA?
- Cessation of smoking
- decreased BP to <120/80
How many times do we need to monitor the patient according to the aortic diameter?
- <3 cm- no ultrasound
- 3-4 cm do a yearly ultrasound
- 4-4.5 cm- ultrasound every 6 months
- 4.5-5.5 cm ultrasound every 3 months
When do we consider elective surgery?
- aneurysm >5.5cm
- expanding more than 1 cm per year
When do we we consider emergency surgery?
- leaking or ruptured AAA
- Acutely symptomatic
What are the surgical procedures we can do?
- EVAR which is preferred over
- open(tube graft and y-prosthesis)
What are the complications of an AAA?
-Rupture
What does EVAR stand for?
Endovascular aneurysm repair
What is the clinical features for a ruptured AAA?
- Throbbing abdominal pain that radiates towards the flank, the back, the buttocks, legs and groin
- nausea and vomiting
What is the treatment for a ruptured AAA?
- emergency open surgery
- sometimes endoscopic surgery
- high mortality rate(90%) if it occurs outside the hospital
What is the possible differential diagnosis for upper abdominal pain with surgery
- Pale: ruptured AAA, ruptured hepatoma, ruptured spleen in trauma
- Not pale: sepsis, pancreatitis, pyenephrosis
Why should we not intubate these patients?
-neuromuscular blocking agents will reduce the tamponade effect and cause haemorrhage
What kind of graft is used?
-a synthetic graft called Dacron
What is the most common complication post-operatively?
Renal insufficiency
How can we stop the complication of renal insufficiency?
-by giving furosemide or mannitol pre-operatively
What are the peri-operative complications of doing EVAR?
- Stroke because of hypotension
- Myocardial infarction
- renal insufficiency
- colon ischaemia
- haemmorrhage
- Infection of the graft
- Gangrene foot when an embolism travels from a thrombus
What is a late complication of EVAR?
- late infection
- aortoenteric fistula
How can you tell the difference between a saccular and fusiform aneurysm?
Fusiform is symmetrical and saccular is asymmetric and bulges out
