Aneurysms Flashcards
Risk factors for AAA
age >50
male
smoking
hypertension
FH
connective tissue disorders
AAA presentation
most are asymptomatic
pain and/or tenderness
rupture = abdominal pain radiating to back, collapse, pulsatile abdominal mass
embolisation = acute limb ischaemia (6Ps), blue toe syndrome
What is blue toe syndrome?
ischaemic toes with palpable foot pulses
suggests microembolisation from atherosclerotic plaque or aneurysm
What size can a normal aorta measure up to?
2.5cm in diameter
What size aorta is considered an AAA?
> =3cm
How can AAA affect driving?
car drivers can continue if <6cm
most notify DVLA between 6-6.4cm
must stop when >=6.5cm
bus/lorry drivers must notify DVLA if <5.5cm and must stop when >=5.5cm
Management of small AAA
antiplatelet and statin
no medications proven to reduce rate of expansion
smoking cessation
HTN treatment
3-4.5cm = 12 monthly surveillance US
4.5-5.5cm = 3-6 monthly surveillance US
Indications for AAA surgery
Asymptomatic:
- diameter >=5.5cm
- increase in size >=1cm in a year
Symptomatic:
- pain and/or tenderness
- rupture
- embolisation
What pre-operative assessments must be done for AAA surgery?
consider age, comorbidities, frailty, patient wishes
CT aortogram
bloods/CXR/ECG/echocardiogram/lung function tests/cardiopulmonary exercise test
anaesthetic pre-assessment
optimise cardiac, respiratory and renal function
Complications of open AAA repair
death
bleeding
ischaemia (limbs, colon)
cardiac, respiratory and renal failure
wound infection, dehiscence, and incisional hernia
adhesive small bowel obstruction
graft infection and aorto-enteric fistula
What is EVAR?
endovascular aneurysm repair
Complications of EVAR
death
contrast and radiation toxicity
wound haematoma, seroma, infection
damage to access vessels
5-10% yearly reintervention rate due to slipping, kinking, thrombosis, endoleak or rupture
lifelong surveillance required
What is an endoleak?
blood flowing outside the stent graft but inside the aneurysm sac
can be low or high pressure
may spontaneously seal with time
may cause sac expansion and rupture
What is a type 1 endoleak?
poor seal between graft and neck or iliacs
uncommon
usually high pressure
always concerning
high risk of rupture
usually treated
What is a type 2 endoleak?
backbleeding lumbar arteries or IMA
common
usually low pressure
only concerning if sac expanding
low risk of rupture
usually under surveillance
may resolve spontaneously
Compare open repair and EVAR for aneurysm repair
Open:
- higher early mortality
HDU bed
- longer in hospital
- longer recovery
- lower late mortality
- less expensive
EVAR:
- lower early mortality
- ward bed
- shorter in hospital
- shorter recovery
- higher late mortality
- more expensive
Who should get open or EVAR for their aneurysm?
open = better for younger, fitter patients
EVAR = better for older, less fit patients
Management of ruptured AAA
Bloods - FBC, U&E, LFT, glucose, amylase, clotting, cross-match (massive transfusion protocol)
ECG
Large bore IV cannula and urinary catheter
Fluid resuscitation to maintain systolic BP 70-90 mmHg (permissive hypotension)
Assess age, comorbidities, frailty. patient and family wishes, advance decisions, quality of life and functional status
Stable patients can have CT scan to confirm diagnosis and assess EVAR suitability
EVAR for stable and anatomically suitable patients
Open repair for unstable patients and those not suitable for EVAR
WHO criteria or screening
condition should be an important health problem for patient and community
should be an accepted treatment or useful intervention
natural history of disease should be understood
should be a latent or early symptomatic stage
facilities for diagnosis and treatment should be available
should be an agreed policy on who to treat
treatment should be more beneficial if started earlier
cost should be economically balanced
case finding should be continuous ad not a once and for all project
Describe the National AAA screening programme (NAASP)
started 2010
all men invited for screening ultrasound in 65th year
older men can self-refer
<3cm = discharged
3-<5.5cm = enrolled in US surveillance
>=5.5cm = referred to surgeon
Type A aortic dissections
start proximal to the left subclavian artery and involve the ascending aorta
Type B aortic dissections
start distal to the left subclavian artery and involve the descending aorta
Aortic dissection risk factors
hypertension
atherosclerosis
aortic aneurysm
bicuspid aortic valve
coarctation
family history
connective tissue disorders
pregnancy
cocaine use
high intensity weight lifting
Aortic dissection presentation
tearing chest pain radiating to back
collapse
pulse deficits
radio-radial or radio-femoral delay
difference in BP between arms >20mmHg
new aortic regurgitation murmur
neurological signs of stroke or paraplegia
Aortic dissection CXR findings
widened mediastinum
pleural effusion/haemothorax
Aortic dissection ECG findings
ischaemic changes if coronary arteries malperfused
Aortic dissection CT angiogram findings
intimal flap
true and false lumen
branch vessel perfusion
Aortic dissection complications
Malperfusion:
- coronary = MI
- carotid = stroke
- spinal = paraplegia
- renal = renal failure
- mesenteric = acute mesenteric ischaemia
- limb = acute limb ischaemia
Rupture
Aneurysmal dilatation
Management of Type A Aortic dissection
open surgery to replace ascending aorta +/- arch +/- aortic valve
may require reimplantation of coronary arteries or great vessels
Management of Type B Aortic dissection
uncomplicated type B:
- analgesia
- strict BP control with IV Labetalol
- surveillance
complicated type B (ongoing pain, uncontrolled BP, malperfusion, aneurysmal dilatation, rupture):
- TEVAR to cover entry tear and promote thrombosis of false lumen
Aneurysm definition
localised dilatation of an artery with at least a 50% increase in diameter compared to the expected normal diameter
(<50% = ectasia)
What is a true aneurysm?
involve all 3 layers of arterial wall
fusiform or saccular in shape
What is a false/pseudo aneurysm?
hole in arterial wall
pulsatile haematoma contained by adventitia and surrounding tissues
Where can true aneurysms be located?
abdominal aorta and iliacs
popliteal
femoral
thoracic aorta
Where can false aneurysms be located?
radial
femoral
anastomotic
Aneurysms presentation
compression or erosion or adjacent structures
rupture
distal embolisation
thrombosis
