Carotid endarterectomy

Indications/contraindications - see separate topic under 'carotid atherosclerotic disease'

Pre-op:

Notify neuro/stroke reg, even if elective/asymptomatic
Cranial and peripheral neurological exam documented pre-op
Patients undergoing carotid surgery after contralateral neck surgery require a cord check prior to OT
If there is high-grade stenosis (80-99%) and there has been a significant delay to surgery, arrange a repeat carotid duplex morning of OT to ensure it's not 100% stenosis

Operative technique (CEA)

Anaesthetic
- GA/regional/LA
Positioning
- Neck extension
- Padded ring under head
- Tube on opposite corner of mouth
- Access to high lesions can be improved by naso-tracheal intubation - keeping mouth closed allows an extra few cm of access between mandible and mastoid, and allows potential TMJ subluxation
Incision
- Longitudinal incision parallel to medial border of SCM
Exposure
- Divide platysma, mobilise medial SCM
- Find external jugular and greater auricular nerve and retract laterally
- Enter carotid sheath
- Medial border of IJV dissected and retracted laterally - look out for facial vein at level of carotid bifurcation and ligate/divide it if necessary
- Vagus nerve identified - posterior between IJV and CCA
- CCA controlled circumferentially with an umbilical tape
- Identify ansa cervicalis (medial to distal CCA) and follow it cranially to hypoglossal nerve
- Superior thyroid artery (medial border of carotid bifurcation) and controlled
- ECA and ICA encircled with vessel loops
- Be aware of carotid body
Procedure
- 70-100 units/kg of heparin IV, then wait 3 mins
- ICA clamped - distal to plaque
- CCA and ECA clamped
- Conventional procedure
  - Vertical arteriotomy and closure with patch angioplasty
  - Begun in CCA and continued through bifurcation into ICA
  - Patch can be Dacron, PTFE or bovine pericardium

Post-op:

Extended recovery (4 hours)
Review for neurological changes, headache, progressive hypertension, and neck bleeding/swelling

Complications to CEA

Mortality - 0.5% - most commonly cardiac disease
Stroke - 1-5% - depends on indication for CEA - higher if symptomatic
MI - 2-4%
Cerebral hyperperfusion syndrome
- Manifests several days after, with migraine-like headaches and possibly seizures and subsequently haemorrhagic stroke
- Occurs due to dysregulation in the setting of severe contralateral carotid diseasej
- This is why strict BP control is paramount
Labile blood pressure - 60% - generally resolves within 4-8 hours
- Hypertension - Rutherford's says IV sodium nitroprusside - titrate to keep to within 200mmHg of pre-op level. Give GTN additionally if myocardial ischaemia is present.
- Hypotension - aim for within 200mmHg of pre-op level by the usual means.
Bleeding requiring re-exploration - 1-4%
Infection <1%
Cranial nerve injury - 5%-17% - mostly transient
- Mostly hypoglossal - ipsilateral tongue weakness and deviation of tongue to affected side
- RLN - hoarse voice
- SLN - early fatiguability of voice and difficulty with voice modulation/mild swallowing difficulty
- Marginal mandibular branch of facial nerve - drooping of ipsilateral lower lip - of little functional significance
- Glossopharyngeal - mild dysphagia to recurrent aspiration
- Spinal accessory nerve
- Greater auricular - numbness of angle of mandible and lower ear
- Transverse cervical - anaesthesia of anterior neck skin
Recurrent carotid stenosis - 5-22%
- Usually results from intimal hyperplasia
- Could actually represent residual disease after first CEA
- Higher chance in women, continue to smoke, hypercholesterolaemia, diabetes, HTN
- 'Early' means within 2 years - typically intimal hyperplasia
- 'Late' is typically because of atherosclerotic disease

Follow-up to CEA

USS duplex 6 weeks post-op (both sides)
Usually 6 monthly carotid duplex USS and review out to 2 years, at which point they can be discharged
Long term risk factor management with GP
Stroke clinic review referral if patient has been symptomatic