Vascular Surgery Flashcards
what are common misdiagnosis for ruptured AAA?
renal colic diverticulitis GI bleed MI mechanical/muscular back pain
how does ruptured AAA present?
sudden, severe, crippling abdo and back pain
bilateral leg ischaemia
hypotension
tachycardia
cold clammy peripheries with poor CRT (generalised shock state)
elderly
how do you differentiate between an expansile aortic mass or a mass above the aorta which is transmitting the pulse?
pulsatile/expansile aorta will move your hands apart
a mass above the aorta will move your hands upwards
what should be suspected in an elderly man who presents with renal colic for the first time??
rupture AAA
when should an aorto-enteric fistula be suspected?
in a patient with a GI bleed and previous aortic surgery
what are the branches of the abdominal aorta ?
1) coeliac trunk (giving off splenic artery, hepatic artery and left gastric) 2) left and right renal arteries 3) superior mesenteric 4) inferior mesenteric
how does the abdominal aorta end?
bifurcates into left and right common iliac (external and internal iliac arteries)
coeliac trunk arises at which vertebral level?
L1
which clamping method in AAA repair surgery puts most and least strain on the heart?
most strain = supra-coeliac clamping
less strain = supra renal clamping
least strain = infra renal clamping
what is the pathophysiology of peripheral vascular disease?
senescence, shear stress or circulating toxins lead to endothelial dysfunction and damage. this leads to artherosclerotic plaque build up,
chronic ischaemia is caused by narrowed lumen and haemodynamic flow limitation
acute ischaemia is caused by plaque rupture and thrombus formation
how is chronic limb ischaemia classified?
fontaine 1 asymptomatic
fontaine 2 claudication
fontaine 3 rest pain
fontaine 4 tissue
how does claudication present?
aching muscles on effort
predictable
worse on hills, with speed
settles swiftly on rest
how does rest pain present?
icy, burning, constant foot ache
worse on elevation or at night
need opiates
what are examples of ischaemic tissue loss?
ulcers, gangrene, necrosis
how is intermittent claudication (PAD) treated?
- stop smoking
- antiplatelet therapy - clopidogrel
- good BP control
- statin - atorovastarin 80mg
- take regular exercise, loss weight
how is PAD assessed in lower limb?
- check limb pulses
- check ABPI (ankle brachial pressure indec)
- 1st line investigation = duplex ultrasound scan
- perform magnetic resonance angiography (MRA) before any intervention
how are ABPI measurements interpreted?
1 = normal
0.6 - 0.9 = claudication
0.3 - 0.6 = rest pain
< 0.3 tissue loss
in which ways can PAD present?
intermittent claudication
critical ischaemia
acute-limb threatening ischaemia
what are the features of a limb threatening ischaemia? 6Ps
Pale Pulseless Painful Paralysed Paraesthesia Perishingly cold
how is critical limb ischaemia/severe PAD treated?
- angioplasty
- stenting
- bypass surgery
- amputation if none of the above are suitable
which drugs are licensed for treatment in PAD?
naftidrofuryl oxalate - vasodilator
for patients with v poor QOL
what is the most common risk assoc. with popliteal artery aneurysm?
thrombosis of the aneurysm
embolisation of mural thrombus
what is the 5 year prognosis for patients with AAA who don’t receive surgery
20% are alive in 5 years
what are the most common causes of mortality after emergency correcting of an AAA?
acute renal insufficiency
myocardial infarction
what does involuntary muscle contractions in an ischaemic limb indicate?
restored flow cannot save the extremity
what are the causes for early pallor in the case of an arterial embolus?
reflex vasoconstriction
hypo-perfusion of skin
which visceral aneurysm is most common?
splenic
what are features of a low rupture risk AAA?
<5.5 cm
asymptomatic
treat with US surveillance and optimise CV risk factors
what are features of a high rupture risk AAA?
> 5.5 cm
or rapidly enlarging (>1cm/year)
symptomatic - intervene regardless of size
how are AAA diameter measurements interpreted?
<2.5 = normal <3.5 = ectasia <4.5 = small AAA >5.5 = large AAA
what are surgical interventions for a severe AAA?
1) elective endovascular repair (EVAR)- access via femoral artery, the aneurysm is fitted with a stent to reline it.aims to prevent blood from collecting. (2% mortality)
2) open repair - affected segment is replaced with plastic graft (tube or bifurcate). clamping puts immense strain on heart. (5% mortality)
what is a complication of EVAR??
endo-leak
the stent fails to exclude blood from the aneurysm
what is MoA of tranexamic acid and what is it used for?
used to prevent blood loss in massive haemorrhage
strong antifibrinolytic
what are 5 common complication associated with massive blood transfusion?
1) dilutional coagulopathy - abnormalities in clotting = due to dilution of platelets and clotting factors.
2) haemolytic reaction (most common) -usually caused by administration of mismatched blood types
3) hypothermia -RBCs are stored at 4 degrees. hypothermia shifts the oxygen dissociation curve so less oxygen delivery. also increases risk of hypocalcaemia, arrhythmias, metabolic acidosis
4) hypocalcaemia - due to present of citrate in tranfused products
5) transfusion related acute lung injury (TRALI) - most common cause of morbidity/death. represents as acute resp distress within 6 hr of transfusion
