Aneurysms Flashcards
What is atherosclerosis of the carotid arteries associated with?
TIA and ischaemic stroke
Causes of stroke
Cerebral infarction (84%) - AF - Carotid atherosclerotic plaque rupture/thrombosis - Endocarditis - MI - Carotid artery trauma/dissection - Drug abuse - Haematological disorder e.g. sickle cell Primary Intracerebral haemorrhage (10%) SAH (6%)
What does SAH stand for?
Subarachnoid haemorrhage
Risk factors for carotid artery stenosis
Smoking DM FH Male HTN Hyperlipidaemia/Hypercholesteraemia Obesity Age
What is Poiseuilles Law in terms of a vessel?
As the radius of the vessel decreases (stenosis), velocity increases
Investigations for carotid artery stenosis / stroke
Neurological examination Cardiac exam Auscultate carotids CT Carotid USS
Treatment of TIA / Stroke
Smoking cessation Control of HTN Antiplatelet (aspirin / clopidogrel) Statin Diabetic control Carotid doppler Carotid endarterectomy Stenting
If one of the carotid arteries are occluded, how is the brain still perfused?
Due to the circle of willis
What can an diseased carotid artery further increase the risk of and why?
Stroke / TIA - emboli could be showered from high velocity flow in a diseased carotid artery, causing distal ischaemia
Should patients with asymptomatic carotid stenosis be treated?
If high grade stenosis (60-99%)
What is an aortic aneurysm disease?
Dilation of all layers of the aorta, leading to an increase in diameter of > 50% (abdominal aorta >3cm)
Causes of aneurysm disease
Degenerative disease
Connective tissue disease (e.g. marfans)
Infection (mycotic aneurysm)
Is a mycotic aneurysm common?
No
Risk factors for degenerative AAA
Male Age Smoking HTN FH
Prevalence of AAA in 1st degree male relatives
30%
What is protective in AAA?
Diabetes
Presentation of AAA
Asymptomatic Aneurysm pulsating Increasing back pain Tender abdomen around aorta Abdo / back / flank pain Painful pulsatile mass Haemodynamic instability (single or progressive) Hypoperfusion
What does a symptomatic AAA indicate?
Impending rupture
Unusual presentations of AAA
Distal embolization Aortocaval fistula Aortoenteric fistula Ureteric occlusion Duodenal obstruction
What is an aortocaval fistula?
Aortic blood going back into the venous system without perfusing the limbs
What is an aortoenteric fistula?
Connection between aorta and intestines, stomach or oesophagus, there can be significant loss of blood into the intestines
Who gets abdominal aortic aneurysm screening?
Men > 65 y/o in England
Criteria for disease screening
Definable disease Prevalence Severity of disease Natural history Reliable detection Early detection confers advantage Treatment available Cost effective Feasibility Acceptability
What would be done in screening if the aorta is found to be normal?
Discharged
How big is a small AAA, and if found in screening, what would be done?
3.0 - 4.4cm
Annual USS scans
How big is a medium AAA, and if found in screening, what would be done?
4.5 - 5.5cm
3 monthly USS scans
How big is a large AAA, and what would be done if found during screening?
> 5.5cm
Send to nearest vascular unit for further work up
Risk of rupture for aneurysm < 4cm
<0.5% per year
Risk of rupture for aneurysm 5 - 5.9cm
3 - 15% per year
Risk of rupture for aneurysm 7 - 7.0cm
20 - 40% per year
Risk of rupture of aneurysm > 8cm
30 - 50%
What must be determined before repair of an aneurysm?
Is it a size to consider to repair?
Is the patient a candidate for repair?
Is the aneurysm suitable for endovascular or open repair?
What size of aneurysms can sit comfortably with frequent surveillance?
< 5.5cm small aneurysms
In the UK, at what size is treatment usually offered for aneurysms?
> 5.5cm
How to determine the patients fitness for repair
History and exam Bloods ECG ECHO PFTs MPS CPEX EOB assessment Patient preference
What does MPS stand for?
Myocardial perfusion scans
What does CPEX stand for?
Cardiopulmonary exercise test
Investigations of AAA
USS
CTA/MRA (contrast scans)
Treatment of asymptomatic AAA
Conservative - not fit for repair - consider in event of rupture Endovascular repair Open repair
How does open repair of AAA work?
Sew in a tube so blood will flow down the tube instead of the aneurysm sac
Complications of open repair of AAA
Wound infection, bleeding, pain, scar Damage to bowel, uterus, veins, berves Distal emboli Renal failure Colonic ischaemia DVT/ PE / MI / Stroke Death
How does an endovascular repair of AAA work?
Femoral arteries in groin used
Catheter with graft - unzip graft and so pings open in the aneurysm sac
Only leaves small scar at groin
Complications endovascular vs open repair
Endovascular much less
Complications of endovascular repair of AAA
Wound infection / Bleeding / Pain / Scar Contrast reaction / kidney injury Radiation Endoleak Femoral artery dissection Damage to femoral vein / nerve Distal emboli DVT / PE / MI / Stroke / Death
What is an endoleak?
When despite the graft, blood is still leaking into the sac
Treatment of symptomatic AAA
ABCDE
Support circulation
Emergency open repair
Emergency EVAR
Why should the patient be kept awake while preparing the abdomen in symptomatic AAA?
The muscles in the abdomen are keeping the bleeding
Mortality of emergency open repair of symptomatic AAA
30 - 50%
What does emergency EVAR have a risk of?
Abdominal compartment syndrome
Branches of common carotid artery
Internal carotid artery
External carotid artery
Where does the internal carotid artery go?
Inside brain
Complications of carotid endarterectomy
Wound infection, Bleeding, Scar
Nerve damage
Perioperative stroke due to plaque rupture
What is an indication for urgent synchronised DC cardioversion in AF?
Signs of HF
