acute arterial ischemia and vascular trauma

Question 1

what is acute limb ischaemia ?

Answer 1

a sudden decrease in limb perfusion

Question 2

what does the effect of sudden arterial occlusion depend on ?

Answer 2

size of the blood vessel occluded and the state of the collateral blood flow

Question 3

what is the aetiology of acute limb ischaemia ?

Answer 3

acute embolic ischaemia
acute thrombotic ischaemia
acute traumatic ischaemia

Question 4

where are we more likely to find an acute embolus causing ischaemia ?

Answer 4

at arterial bifurcation
whether aortic, iliac , femoral or popliteal

Question 5

what is the difference between embolic and thrombotic ischaemia ?

Answer 5

with embolic ischaemia a relatively healthy artery is affected whereas thrombotic there is already an underlying pathology

Question 6

what are the consequences of having an embolus in each of these organs ?
brain
retina
mesenteric vessels

Answer 6

brain - TIA or stroke
Retina- Amaurosis fugax or permanent blindness
mesenteric vessels- intestinal angina or intestinal gangrene

Question 7

when is claudication pain present ?

Answer 7

claudication pain is only present with thrombosis

Question 8

what are the risk factors for acute embolic occlusions ?

Answer 8

atrial fibrillation
recent AMI
prosthetic heart valves

Question 9

what are the risk factors for acute thrombotic occlusions ?

Answer 9

no specific risk factors but the blood vessels are diseases (underlying pathology)

Question 10

what is the clinical presentation for acute limb ischaemia ?

Answer 10

pain 
paralysis 
pulseless 
perishingly cold 
pallor 
paraesthesia

Question 11

in terms of colour changes what are the differences in late and early stages of acute limb ischaemia ?

Answer 11

early –> pale in colour

late –> cyanosed then mottling then fixed mottling and cyanosis

Question 12

what does the loss of motor function indicates ?

Answer 12

indicates advanced limb threatening ischaemia

Question 13

what is an indication of late irreversible ischaemia ?

Answer 13

muscle turgidity

Question 14

which muscles are first affected with acute limb ischaemia ?

Answer 14

intrinsic foot muscles followed by the leg muscles

Question 15

why is it difficult to detect early muscle weakness ?

Answer 15

because toe movements are produced mainly by leg muscles

Question 16

what does poikilothermic mean ?

Answer 16

when the limb acquires the temperature of the surroundings due to the lack of perfusion

Question 17

what is the staging of acute limb ischaemia ?

Answer 17

I: Viable
IIA: Marginally threatened
IIB: immediately threatened
III: Irreversible

Question 18

in which stage of acute arterial ischaemia would there be rest pain ?

Answer 18

stage IIB where the limb is immediately threatened

Question 19

what kind of investigations would you carry out ?

Answer 19

doppler/duplex ( duplex not so much routine)
angiography ( CTA/MRA) –> CTA is the first line
digital subtraction angiography

Question 20

which imaging modality would be avoided with patients with limited renal function ?

Answer 20

avoid CTA , perform MRA

Question 21

what are the goals of therapy with acute ischaemia ?

Answer 21

prevention of propagation
restoration of blood flow
preservation of the limb
prevention of recurrence

Question 22

what is the immediate management with ALI ?

Answer 22

give the patient IV heparin and analgesia

Question 23

what would the management options acordingto the stagging of the ritheford clasaification ?

Answer 23

stage I- imaging
Stage IIa- imaging
stage IIb - imaging if no delay
stage III- amputation

Question 24

what are the methods of revascularization ?

Answer 24

thromboelectomy
catheter directed thrombolysis
endovascular techniques
bypass surgery

Question 25

what are some simple measure that can be taken to improve existing perfusion ?

Answer 25

keep the foot dependent 
avoid pressure over the heel 
avoid extremes of temperature
maximize tissue oxygenation 
correct hypotension 
start treatment of any other associated conditions

Question 26

how would we intervene in a case of embolic occlusion ?

Answer 26

embolectomy using a Fogarty catheter , an arrteriotomy through the common femoral artery ( balloon and catheter)

Question 27

how would you intervene in the case of an acute thrombotic occlusion ?

Answer 27

first perform an arteriogram then for intervention:
a long segment occlusion - surgical bypass
short segment occlusion - thrombolytic therapy then we can perform either balloon angioplasty or vascular bypass

Question 28

what intervention could be performed with traumatic vascular disease ?

Answer 28

end to end anastomosis with autologous vein graft

Question 29

what are the possible complications following intervention?

Answer 29

• reperfusion syndrome
• recompartment syndrome
• catheter related

Question 30

what are the complications of reperfusion injury ?

Answer 30

myocardial injury 
remote lung injury 
renal injury
gastrointntestinal 
compartment syndrome

Question 31

what is the treatment for compartment syndrome ?

Answer 31

urgent fasciotomy to release the compression

Question 32

what are the mechanisms of vascular trauma ?

Answer 32

blunt
penetrating
iatrogenic

Question 33

what are the hard signs?

Answer 33

absent or diminished distal pulses 
active haemorrhages 
expanding hematoma 
bruit 
distal ischaemia

Question 34

what are the soft signs ?

Answer 34

small, stable hematoma 
injury to anatomically related nerve 
unexplained hypotension 
Hx of haemorrhages
proximity of injury to major vessel

Question 35

what are the myocardial depressant factors ?

Answer 35

C3a TxA2 LTD4

Question 36

when is the best time of management ?

Answer 36

within the first 6 hours

Question 37

what is the gold standard of investigation ?

Answer 37

Angiography

Question 38

what are the different sources of embolism ?

Answer 38

cardiac sources - left atrium in atrial fib, mural thrombus in MI, endocarditis, valvular disease

arterial sources - aneurysm, atherosclerotic plaque, aneurysm

paradoxical

Question 39

what are the sources off thrombosis ?

Answer 39

atherosclerosis
vascular graft
thrombosis of an aneurysm
entrapment syndrome
hypercoaguable state
low flow state

Question 40

what manoeuvre is completely contraindicated in acute limb ischemia ?

Answer 40

raising the leg