Carotid Artery disease and Aneurysms Flashcards
Pathogenesis of Carotid Artery Disease
- Turbulent flow promotes atherosclerosis and plaque formation
- Plaque rupture → complete occlusion or distal emboli
Investigations of carotid artery disease
Bloods - FBC, U+Es, Clotting, lipid profile and glucose
ECG - AF
Duplex carotid Doppler - if post TIA do to rule out CVD
MRI angiography
Mx of carotid artery disease
Conservative:
• Aspirin or clopidogrel
• Control risk factors
Surgical: Endarterectomy
• Symptomatic - Perform w/i 2wks of presentation
Endarterectomy
Surgical procedure to remove the atheromatous plaque material, or blockage
Complications of Endarterectomy
• Stroke or death • HTN • Haematoma • MI • Nerve injury: - Hypoglossal: ipsilateral tongue deviation - Great auricular: numb ear lobe - Recurrent laryngeal: hoarse voice
Advantages and disadvantages of stenting
Benefits: • Less invasive: • ↓ hospital stay • ↓ risk of infection • ↓ risk of CN injury
Disadvantages:
• ↑ stroke risk, pts. >70yrs
Aneursym
Abnormal dilatation of a blood vessel >50% of its normal diameter
Classification of aneurysms
- True Aneurysm
- False Aneurysm
- Dissection
True Aneurysm
Dilatation of a blood vessel involving all layers of the wall and is >50% of its normal diameter
- Fusiform: e.g AAA
- Saccular: e.g Berry aneurysm
False Aneurysm
Collection of blood between the media and adventitia layers that communicates with the vessel lumen.
Usually iatrogenic: puncture, cannulation
Pulsatile lump which is tender and painful
Dissection
Vessel dilatation caused by intima separating from the media to form a channel within the vessel wall.
Causes of aneurysms
Congenital:
- ADPKD → Berry aneurysms
- Marfan’s, Ehlers-Danlos
• Acquired
- Atherosclerosis
- Trauma: e.g. penetrating trauma
Complications of aneurysms
- Rupture
- Thrombosis
- Distal embolisation
- Pressure: DVT
- Fistula (IVC, intestine)
Popliteal Aneurysm
Presentation:
• Very easily palpable popliteal pulse
• may be bilateral
• can cause acute limb ischaemia
Mx: • Acute: embolectomy or fem-distal bypass • Stable: - Elective grafting + tie off vessel - Stenting
AAA presentation
• Usually asymptomatic
Symptoms: • Back pain or umbilical pain radiating to groin • Acute limb ischaemia • Blue toe syndrome: distal embolisation • Acute rupture
Examination:
• Expansile mass just above the umbilicus
• Bruits may be heard
• Tenderness + shock suggests rupture
Mx of AAA
- 3- 4.4 cm - annual USS
- 4.5 - 5.4cm - 3 monthly USS
Risk factor reduction:
- smoking cessation
- blood pressure control
- statin and aspirin therapy
- weight loss
Surgical
• Aim to treat aneurysm before it ruptures
• Open or endovascular aneurysm repair
If > 5.5 do CY scan with contrast for surgical planning
Indications for AAA surgery
- Symptomatic (back pain = imminent rupture)
- Diameter >5.5cm
- Rapidly expanding: >1cm/yr
- Causing complications- emboli
Screening AAA
UK men offered one-time USS screen at 65yrs
Risk factors for AAA rupture
- ↑BP
- Smoker
- Female
- Strong FH
Presentation of AAA rupture
• Sudden onset severe abdominal pain
- Radiates to back or flanks
• Collapse → shock
• Expansile abdominal mass
Mx of AAA rupture
Surgical emergency:
• High flow O2
• 2 x large bore cannulae
- Give fluid if shocked but keep SBP <100mmHg
- Give O- blood if desperate
- Blood: FBC, U+E, clotting, amylase, G+S 10u, crossmatch
• Instigate the major haemorrhage protocol
• Call vascular surgeon, anaesthetist and warn theatre
• Analgesia
• Abx prophylaxis: cef + met
• Urinary catheter + CVP line
• If stable + diagnosis certain: US or CT may be feasible
Aortic Dissection presentation
• Sudden onset, tearing chest pain - Radiates through to the back •Tachycardia and hypertension • Distal propagation → occlusion of branches - Unequal arm pulses and BP
• Proximal propagation
- Aortic regurgitation
- Tamponade
• Rupture into pericardial, pleural or peritoneal cavities
Type A aortic dissection
- Involves ascending aorta ± descending
- Higher mortality due to probable cardiac involvement
- Require surgery
Type B aortic dissection
- Involves descending aorta only: distal to left subclavian artery
- Usually best managed conservatively
Investigations of aortic dissection
- Bloods: G+S, FBC, U+E, clotting, trop I
- ABG
- ECG: exclude MI
- TTE / TOE: can use in haemodynamically unstable pts
- CT - Gold standard but not suitable for unstable pts.
- CXR
Mx of aortic dissection
• Analgesia
• ↓SBP:
- Labetalol - keep sBP 100-110mmHg
- Type A: open repair
- Type B: conservative initially
- Surgery if persistent pain or complications
- Consider TEVAR if uncomplicated
Degree of Stenosis
Mild <50%
Moderate 50-69%
Severe 70-99%
Total Occlusion 100%
Risk factors
Age (≥65 years)
Smoking
Hypertension, Hypercholesterolaemia, Obesity
Diabetes mellitus
History of cardiovascular disease
Family history of cardiovascular disease.
When is carotid endarterectomy done
Stenosis of more than 50%
Mx of acute stroke
High flow oxygen
Blood glucose optimisation
Swallowing screen
CT scan
Ischaemic - IV alteplase within 4.5 hrs of onset and aspirin
Haemorrhagic - neurosurgery
Long term mx of stroke
Anti-platelet therapy - aspirin 300mg for two weeks then clopidogrel 75mg OD
If not tolerated, trial combination therapy aspirin and dipyradimole
Statin therapy - atorvastatin 80mg
Aggressive management of hypertension and/or diabetes mellitus
Smoking cessation
Regular cardiovascular exercise and active lifestyle with weight loss
Referral to the Speech and Language Therapy (SALT) team is advised for any dysphagia or dysphasia
Investigations for AAA
USS
CT with contrast - 5.5 cm
DVLA and AAA
Any AAA >6.5cm requires notification to the DVLA and disqualifies from driving until repaired
When is aortic aneurysm surgically managed
AAA >5.5cm
AAA expanding at >1cm/year
Symptomatic AAA
Complications of EVAR
Endovascular leak
Acute and chronic aortic dissection
Acute: diagnosed ≤14 days
Chronic: diagnosed > 14 days
Presentation of aortic dissection
Tearing chest pain
Tachycardia Hypotension due to hypovalaemia
New aortic regurgitation murmur
Signs of end-organ hypoperfusion such as reduced urine output, paraplegia, lower limb ischaemia, abdominal pain
Ix for psuedoaneurysms
Routine bloods (FBC, CRP, U&Es, clotting, Cross match
USS - turbulent forward and backward flow (termed “yin-yang sign) - gold standard
Blood culture
Pus MC+S
G+S with cross match
Mx of psuedoaneurysms
USS guided compression - do not insert needle
- surgical ligation
- bypass graft if ischaemic
Where do most AAA rupture
Posteriorly into the retroperitoneal space
Is rapid correction of hypotension required in this pt
No as will exacerbate bleed - can cause clots to spread
Aim for < 100 mmHg systolic - permissive hypotension
Which nerves can be damaged during a carotid endarterectomy
Glossopharyngeal- most common
Hypoglossal
Vagus
Pseudoaneurysms
Aetiology:
- IVDU or trauma
Pathophysiology:
- tear between tunica media and adventitia
Highest risk of rupture
Pseudoanuerysm
