Peripheral Vascular Disease Flashcards

1
Q

what is an aneurysm

A

dilatation of a vessel by more than 50% of its normal (AP) diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the normal aortic diamter

A

1-2 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe a true aneurysm

A

all three layers of vessels are in tact, blood is contained (usually abdominal aortic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

describe a false aneurysm

A

when there is a breach in vessel wall and surrounding structures are acting as vessel- usually caused by trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

name three morphology of aneurysms

A

saccular, fusiform, mycotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe what gives rise to mycotic aneurysms

A

secondary to and infectious process that weakens the artery wall, involves all three layers of the artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

which aneurysms have highest risk of rupturing

A

any can but saccular and mycotic more than fusiform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

does atherosclerosis cause aortic aneurysms

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what causes aortic aneurysms

A

medial degeneration

  • middle layer of vessel wall
  • imbalance between elastin and collagen in aortic wall
  • this leads to weakening of the wall
  • which leads to aneurysmal dilatation
  • increase in aortic wall stress
  • progressive dilatation

related to age, gender, smoking, hypertension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

a quarter of AAA patients will have what

A

popliteal aneurysm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how do asymptomatic aneurysm present (vast majority)

A

no symptoms, identified om imaging/ surveillance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how do symptomatic aneurysm present

A
  • pain (renal colic)
  • trashing- thrombus in aneurysm due to turbulent blood flow breaks off and enters peripheral circulation, damaging distal arteries
  • rupture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does a ruptured AAA present

A

sudden onset epigastric/ central pain
-may radiate through to back
-may mimic colic
collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is found on examination of a ruptured AAA

A

may look well

hypo/hypertensive due to pain

pulsatile, expansile mass +/- tender

pulse transmitted from mass to flanks

hard to palpate due to obesity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe the small amount of ruptured AAAs that make it to hospital

A

retroperitoneal usually, rupture contained by retroperitonium- tamponades itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how severe are free intra-peritoneal rupture

A

rapidly fatal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

when should intervention be taken for an AAA

A

balance fitness of patient and risk of rupture

if symptomatic or when asymptomatic and;
-size > 5.5cm AP diameter
or
-expanding >0.5cm/6 months or >1cm/ year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does duplex ultrasound shows, its pros and cons

A

no radiation or contrast

only shows AP diameter and involvement of (iliac) arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe a CT scan- aterial phase

A

IV contrast in aterial system shows aneurysm morphology, shape, size, iliac involvement. AND only one to show if ruptured

allows management planning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe open repair of an aneurysm

A

laparotomoy to access it

clamp aorta and iliacs (for bloodless field)

dacron (polyester) graft (tube and bifurcated) anatstomosed onto artery

essential to close aneurysm sac over graft as bowl will stick to it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe Endovascular Aneurysm Repair (EVAR)

A

exclude the aneurysm from within the vessel, graft inserted via peripheral artery, guided via x-ray. seal needed between tops of stent graft and vessel to prevent blood escaping into the sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is acute limb threat

A
  • acute limb ischaemia
  • acute on chronic limb ischaemia
  • diabetic foot sepsis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is acute limb ischaemia

A

sudden loss of blood supply to a limb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what causes acute limb ischaemia

A

occlusion of native artery or bypass graft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what can cause a sudden occulsion of an artery
``` Embolism Atheroembolism- narrowing, bits break off Arterial dissection Trauma e.g. dislocating knee Extrinsic compression- tumours ```
26
what are the clincal features of acute limb ischaemia
``` 6 P's Pain- excruciating Pallor Pulseless (arteries distal to blockage) Perishingly cold Paraesthesia- nerve begins to die, what makes it so painful Paralysis ```
27
what are the aspects of acute limb ischaemia given in a history
No prior history of claudication- cramping Known cause for embolism Full complement of contra-lateral pulses (all pulses on other side)
28
describe the pain of acute limb ischaemia
Severe, sudden onset, resistant to analgesia Calf/muscle tenderness with tight (‘woody’) compartment indicates muscle necrosis Often irreversible ischaemia
29
why is pallor a symptom of acute limb ischaemia
Limb initially white with empty veins
30
why does the limb appear mottled as the acute limb ischaemia progresses
capillaries fill with stagnated de-oxygenated blood giving a mottled appearance
31
what does blanching mottling mean
salvageable if prompt revascularisation
32
what does non blanching mottling suggest
irreversible ischaemia as artiers distal to the occlusion fill with propagated thrombus with rupture of capillaries
33
why does ALI cause paralysis
as sensorimotor deficit indicative of muscle and nerve ischaemia
34
what happens after 12 hours of ALI
fixed mottling, paralysis, non salvageable
35
why do you never perfuse a non salvageable leg
as will release noxious chemical from dead muscle, killing the patient
36
why are anticoagulants given in ALI
stops propagation of thrombus, may improve perfusion (careful as surgery may be needed)
37
what tests are given on a patient presenting with an ALI
ABC, bloods, troponin, ECG (MI, dysrhythmia), CXR (underlying malignancy), arterial imaging (to plan appropriate management- CT angiogram/ catheter angiogram)
38
what are the managements for ALI if the limb is salvageable
Embolectomy (balloon catherter) +/-fasciotomies +/- thrombolysis
39
what are the managements for ALI if the limb is not salvageable
palliation or amputation
40
what do diabetic foot problems include
diabetic neuropathy, peripheral vascular disease, infection
41
what can combinations of diabetic foot problems lead to
tissue loss; ulceration, necrosis and gangrene = may result in amputation
42
what is the source of sepsis
break in skin (don't notice because of neuropathy), infection from nail plate or inter-digital space, neuro-ischaemic ulcer (secondary to neuropathy and repetitive trauma- increased pressure in feet)
43
why is infection in the foot such a big problem
as muscles confined in rigid compartment which does not allow pus to escape, causing a build up of pressure which impairs capillary blood flow and further ischaemia and tissue damage. Can rapidly progress to sepsis and limb loss
44
what are the systemic finding in diabetic foot sepsis
``` Pyrexia Tachycardic Tachypnoeic Confused Kussmauls breathing (deep sighs- sepsis causes shock, hyper perfusion of distal organs and build up of lactic acid and CO2, trying to ventilate this acid out and raise pH) ```
45
what are the local finding of diabetic foot sepsis
Swollen affected digit (‘sausage’ like) Swollen forefoot (‘boggy’ feeling to swelling) Tenderness Ulcer with pus extruding Erythema (redness of the skin), may track up the limb Patches of rapidly developing necrosis Crepitus in the soft tissues of the foot (Gas from gas forming organisms in soft tissues) Pedal pulses may or may not be present local findings may be tip of iceberg
46
how is diabetic foot sepsis considered
vascular surgical emergency
47
how is diabetic foot sepsis treated
antibiotics (got to cover gram +ve cocci, gram -ve bacilli and anaerobes) rapid surgical debridement of infected tissue, wound open to encourage drainage
48
when is a guillotine amputation done
to break cycle of infection, not neat stump, just clean above the ankle
49
what forms plaques in atherosclerosis
activated platelets, LDL cholesterol, inflammatory cells (WBD->macrophages->foam cells)
50
what is the role of collateral vessels in intermittent claudications
find way around blockage
51
what are the non invasive investigations of lower limb ischaemia
measurement of ABPI, duplex ultrasound scanning
52
what are the invasive investigations of lower limb ischaemia
magnetic resonance angiography, CT angiography, catheter angiography
53
what is ABPI
ankle brachial pressure index (ankle pressure over brachial pressure)
54
is it when ABPI is increased or decreased that there is a problem
drops
55
how does narrowing of artery affect blood flow
turbulent flow
56
how is progression of lower limb ischaemia slowed
stop smoking, lipid lowering, antiplatelets, hypertension Rx, diabetes Rx, life style issues
57
how are claudication symptoms treated
exercise training, drugs, angioplasty/stenting, surgery
58
what inflow surgery can treat lower limb ischaemia
endarterectomy, bypass,
59
what outflow surgery can treat lower limb ischaemia
bypass
60
describe the symptoms of critical limb ischaemia
rest pain- toe/foot ischaemia (when lying/sleeping) ulcers/gangrene- severe ischaemia +damage (trauma + footwear) worse at night helped by sitting putting the leg in a dependent position and walking
61
what are the clinical features of critical limb ischaemia
``` cool to touch absence of peripheral pulses colour change hair loss thick nails shiny skin venous guttering ulcers gangrene ```
62
what are the risk factors for critical limb ischaemia
smokin, diabetes, hypertension, raised cholesterol
63
how is critical lower limb ischaemia treated
analgesia, angioplasty/ stenting, surgery/ amputation (depends on function and patients chance of recovery)