Abdominal Aortic Aneurysm

Question 1

what is an aneurysm?

Answer 1

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

Question 2

what is normal aortic diameter?

Answer 2

1.2-2 cm

Question 3

what is a true aneurysm?

Answer 3

the vessel wall is intact

Question 4

what is a false aneurysm?

Answer 4

there is a breach in vessel wall (surrounding structures act as vessel wall)

Question 5

what are the 3 shapes of aneurysm?

Answer 5

saccular
fusiform
mycotic

Question 6

when do mycotic aneurysms arise?

Answer 6

secondary to a infectious process, involving all 3 layers of the artery

Question 7

what is the medical degeneration in an AAA?

Answer 7

regulation of elastin/collagen in aortic wall
aneurysmal dilatation
increase in aortic wall stress
progressive dilatation

Question 8

what are the risk factors for an AAA?

Answer 8

age
gender
smoking
hypertension
atherosclerosis

Question 9

how are asymptomatic AAAs identified?

Answer 9

imaging for other pathology

surveillance

Question 10

how are symptomatic AAAs identified?

Answer 10

pain- may mimic renal colic
‘trashing’
rupture

Question 11

describe the progression of a rupture of an AAA

Answer 11

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

Question 12

describe the exam of somebody with a symptomatic ruptured AAA

Answer 12

may look 'well'
hypo/hypertensive
pulsatile, expansile mass +/- tender
transmitted pulse
peripheral pulses

Question 13

what are the types of rupture?

Answer 13

most retroperitoneal, contained rupture

free intra-peritoneal rupture is rapidly fatal

Question 14

when to intervene with a symptomatic AAA?

Answer 14

pain
‘trashing’
rupture

Question 15

when to intervene with an asymptomatic AAA?

Answer 15

size- >5.5 cm

expansion- 0.5cm/6 months

Question 16

what is used for surveillance of AAAs?

Answer 16

duplex ultrasound

Question 17

when is a CT scan used?

Answer 17

when contrast is in arterial system

Question 18

what is a duplex ultrasound used for?

Answer 18

• AP diameter

- involvement of iliac arteries

Question 19

what is a CT scan used for?

Answer 19

shape, size, iliac involvement
allows for management planning
only imaging method to identify ruptured AAA

Question 20

how is an AA managed?

Answer 20

open repair

• laparotomy
• clamp aorta + iliacs
• dacron graft
• tube vs bifurcated graft

Question 21

describe endovascular aneurysm repair

Answer 21

exclude AAA from ‘inside’ the vessel
inserted via peripheral artery
x ray guided
modular components

Question 22

what is acute limb ischaemia?

Answer 22

sudden loss of blood supply to a limb due to occlusion of native artery or bypass graft

Question 23

what are the causes of a sudden occlusion?

Answer 23

embolism 
atheroembolism
arterial dissection
trauma
extrinsic compression

Question 24

what are the clinical features of acute limb iscahemia

Answer 24

6 Ps
pain
pallor
pulseless
perishingly cold
paraesthesia
paralysis

no prior history of claudication
known cause for embolism
full complement of contra-lateral pulses

Question 25

describe the pain of acute limb iscahemia

Answer 25

severe, sudden onset, resistant to analgesis

calf muscle tendereness with tight compartment indicates muscle necrosis- often irreversible

Question 26

describe the pallor of acute limb iscahemia

Answer 26

limb initially white with empty veins
later, capillaires fill with atgnated de-oxygenated blood giving a mottled appearance
arteries distal to occlusion fill with propaganted thrombus with rupture of capillaries

Question 27

describe blanching mottling

Answer 27

salvageable if prompt revascularisation

Question 28

describe non blanching mottling

Answer 28

irreversible ischaemia

Question 29

describe the paraesthesia/paralysis of acute limb ischaemia

Answer 29

sensorimotor deficit are indicative of muscle and nerve ischaemia
salvageable if prompt revascularisation

Question 30

describe 0-4 hours

Answer 30

white foot
painful
sensorimotor deficit
salvageable

Question 31

describe 4-12 hours

Answer 31

mottled
blanches on pressure
partly reversible

Question 32

describe >12 hours

Answer 32

fixed mottling 
non blanching
compartments tender/red 
paralysis
non salvageable

Question 33

describe the management of acute limb ischaemia

Answer 33

ABC
FBC, U/Es, CK, coag +/- troponin 
ECG- MI, dysrhythmia 
CXR- underlying malignancy 
anticoagulate

Question 34

what are diabetic foot problems?

Answer 34

diabetic neuropathy
peripheral vascular disease
infection
all of which lead to tissue ulceration, necrosis and gangrene

Question 35

why would diabetic foot sepsis occur?

Answer 35

simple puncture wound
infection from the nail plate or inter-digital space
from a neuro-ischaemic ulcer

Question 36

why is foot infection a problem?

Answer 36

infection tracts in the soft tissue into this rigid compartment
if the build up of pus cannot escape, the pressure builds up in this rigid compartment rapidly leading to impairment of capillary blood flow and further iscahemia and further tissue damage

Question 37

what are the clinical systemic findings of diabetic foot sepsis?

Answer 37

Pyrexia
Tachycardic
Tachypnoeic
Confused
Kussmauls breathing

Question 38

what are the local clinical findings of diabetic foot sepsis?

Answer 38

Swollen affected digit (‘sausage’ like)
Swollen forefoot (‘boggy’ feeling to swelling)
Tenderness
Ulcer with pus extruding
Erythema, may track up the limb
Patches of rapidly developing necrosis
Crepitus in the soft tissues of the foot (Gas from gas forming organisms)

Question 39

what is the management of diabetic foot sepsis?

Answer 39

treated as vascular surgical emergency
Appropriate antibiotic should be administered at the earliest opportunity
Rapid surgical debridement of infected tissue
Remove all infected tissue
Wound open to encourage drainage

Question 40

what is the aftercare of diabetic foot problems?

Answer 40

further problems can be prevented with adequate education, foot assessment (diabetic foot clinic, podiatrist) and pressure offloading footwear