Cardio: Aneurysms Flashcards
1
Q
what is an aneurysm?
A
an abnormal dilatation of an artery
2
Q
classification of aneurysms
A
- true aneurysm
- false aneurysm
3
Q
what is a true aneurysm?
A
this contains all layers of the vessel wall; appears as either a fusiform or a saccular dilatation
4
Q
what is a false aneurysm?
A
these do not contain all layers of the arterial wall; usually involves only a collection of blood in the adventitia
5
Q
causes of true aneurysm
A
- congenital: berry aneurysm of circle of Willis, aneursymal varices associated with AV fistula, connective tissue disorders (Marfan’s, Ehlers-Danlos), inflammatory (Takayasu’s aortitis)
- acquired: trauma (irradiation) infection (syphilis, mycotic aneurysm), degeneration (arteriosclerosis, cystic medical necrosis), atheroma
- the bigger the aneurysm, the quicker it will expand
6
Q
causes of false aneurysm
A
trauma
7
Q
common sites of aneurysm
A
- aorta (more commonly, infrarenal)
- iliac artery
- femoral artery
- popliteal artery
8
Q
complications of an aneurysm
A
- rupture
- thrombosis
- distal emboli
- fistula
- pressure on other structures
9
Q
types of aortic aneurysms
A
- thoracic
- thoracoabdominal
- abdominal
10
Q
where can the aorta dilate
A
from the ascending aorta to the aortic bifurcation
11
Q
why do aneurysms occur?
A
degeneration of the elastic lamellae and smooth muscle loss
12
Q
from when is aorta considered to have an aneurysm?
A
greater than 3cm across
13
Q
risk factors for aneurysms
A
- elastic degeneration due to increased levels of metalloproteinases
- flow dynamics
- hypertension (involved in formation and rate of expansion)
- atherosclerosis
- collagen defects
- genetic association
- smoking (associated with a more rapid expansion)
- associated with emphysema and inguinal hernias
14
Q
symptoms of aneurysms
A
- mainly asymptomatic
- backache (pressure on the vertebral bodies)
- sign: pulsatile abdominal mass just above the umbilicus
15
Q
investigation of aneurysms
A
- ultrasound (assess the diameter)
- CT scan
- pre-op investigations: FBC, U&E, clotting studies, ECG, CXR, lung function tests, ABGs, echo
16
Q
where can aneurysm bleed into?
A
retroperitoneal or intraperitoneal or into the IVC (AV fistula)
17
Q
management of aortic aneurysm
A
- depends on the size
- <5cm: monitored annually if <4.5cm or biannually if >4.5cm
- > 5cm: investigated to check whether he is fit for surgery
- only aneurysms >5.5cm (>5cm in women) are considered for surgery or if the patient is symptomatic
18
Q
treatment options of aortic aneurysm
A
- EVAR (endovascular repair - stenting)
- open surgery
19
Q
risk factors for aortic dissection
A
- hypertension
- smoking
- female
- strong family history
- COPD
- shape of aneurysm (saccular>cylindral)
20
Q
symptoms of ruptured abdominal aortic aneurysm
A
- intermittent/continuous abdominal pain
- radiating to the back, iliac fossae or groins
- expansile abdominal mass
- collapse and shock
21
Q
how do you know that the patient has an adequate blood pressure
A
conscious and talking
22
Q
what happens if the aorta dissects and there is an AV fistula with the IVC
A
- severe heart failure
- massive lower limb oedema
23
Q
investigations of dissected AAA
A
- should be clinically obvious
- if not, CT and US
24
Q
management of dissected AAA
A
- emergency style
- call the vascular surgeon before doing anything else
- amylase, Hb, crossmatch, ECG
- take the patient straight to theatre
25
what are inflammatory aneurysms?
one where the walls become thickened and inflamed
26
which arteries can iliac artery aneurysms involve
- common iliac
| - internal iliac
27
associations of iliac artery aneurysm
- associated with AAA
| - rarely occur in isolation
28
management of iliac artery aneurysm
- open surgery using Dacron
- endovascular stenting
- in internal iliac artery, ligation if the other is still patent
29
symptoms and signs of femoral artery aneurysm
- asymptomatic pulsatile mass in the groin
- associated with AAA
- compression of local structures, thrombosis, ischaemia, distal emboli and rupture
30
causes of false aneurysms in the femoral artery
- percutaneous catheterisation for angiography; stab wounds
| - previous surgery, especially with prosthetic grafts (infection)
31
treatment of femoral aneurysms
- small: monitor or treat if symptomatic
- if rapidly expanding, surgery
- iatrogenic false: compression therapy
32
signs and symptoms of popliteal aneurysm
- mass behind the knee
33
complications of popliteal aneurysm
- thrombosis with compromise of the distal circulation and distal embolism
- compression of local structure
34
treatment of popliteal aneurysm
- considered if >2cm
- open surgery is preferred
- exclusion bypass
- in-lay graft
35
what are the visceral artery?
- splenic artery
- hepatic artery
- superior mesenteric artery
- renal artery
36
signs and symptoms of visceral artery aneurysms
- abdominal/flank pain
| - renal: haematuria/hypertension
37
how are visceral aneurysms diagnosed?
- ultrasound scanning
| - arteriography
38
why are splenic artery aneurysms important?
- they can present at the 3rd trimester of pregnancy
| - if >2.5cm, they should be treated
39
affects of a thoracic aortic dissection
- carotid artery: hemiplegia
- anterior spinal artery: unequal arm pulses and blood pressure, acute limb ischaemia, paraplegia
- renal arteries: anuria
40
complications of thoracic aortic dissection
- aortic valve incompetence
- inferior myocardial infarction
- cardiac arrest
41
types of thoracic aortic dissections?
type A and type B
42
what are type A dissection?
- ascending aorta
| - consider these for surgery
43
what are type B dissection?
- medical management
| - surgery is reserved for distal dissections that are leaking, ruptured or compromising vital organs
44
management of thorcic aortic dissection
- crossmatch 10U blood
- ECG & CXR
- CT/MRI or TOE
45
what is a false aneurysm?
- pulsating haematoma, the cavity of which is in contact with the arterial lumen
- made of a fibrous capsule made of adventitia
46
what happens in IVDU with false aneurysm
- infection might be present (has to be treated)
- if all of the vessels have been damaged, ligate all the vessels
- this is associated with a high rate of limb loss and disabling claudication
47
how would you do an open surgery?
- umbilical/paraumbilical/transverse incision
- push the omentum and bowel out of way
- put a banding around the neck of the aneurysm
- clamp any arteries found in the surroundings
- open the sac to remove the thrombus
- put a piece of graft in according to the patient's aorta and then, suture the sac around it
48
how would you do an EVAR?
- small transverse cut in the groin
- pass the wire through the artery into the heart
- mount the graft onto the tube
- the graft is fixed in placed via barbs on top
- once the position is good, the spring opens and seals the graft onto the vessel
- this is monitored using CT/angiography
- the aneurysmal sac should thrombose and shrink with time
