Carotid endarterectomy

Surgical approach

Indication: symptomatic or high-risk carotid stenosis; aim is to reduce stroke risk by removing atheromatous plaque from internal carotid artery (ICA).
- Typically performed for symptomatic 50–99% stenosis (greatest benefit in 70–99%); selected asymptomatic patients with high-grade stenosis may be offered CEA depending on local policy and surgical risk.
Positioning: supine, head turned away; shoulder roll; neck extended; careful padding and avoidance of excessive neck rotation (cervical spine disease).
Incision along anterior border of sternocleidomastoid; dissection to expose common carotid artery (CCA), external carotid artery (ECA), ICA; identification/preservation of cranial nerves (VII marginal mandibular, IX, X, XII).
Heparinisation before clamping; carotid cross-clamp applied (CCA/ECA/ICA).
- Selective or routine shunt may be used to maintain cerebral perfusion during clamp (based on stump pressure, EEG/NIRS/TCD, or awake neurological status under regional).
Arteriotomy and endarterectomy (plaque removal); closure with primary closure or patch angioplasty (reduces restenosis).
Reperfusion/unclamping sequence (often ECA then CCA then ICA) to reduce embolic load; meticulous de-airing and flushing.
Haemostasis; drain sometimes; closure. Potential conversion to carotid artery stenting is uncommon intra-op but relevant in hybrid settings.

Anaesthetic management (overview)

Type of anaesthesia: GA or regional (cervical plexus block ± sedation). Choice depends on patient factors, surgeon preference, and local outcomes.
- Regional allows continuous neurological assessment; GA offers airway control and immobility.
Airway: GA usually with ETT (preferred for controlled ventilation, CO2 control, and airway protection). SGA generally avoided (access to head/neck, need for tight BP/CO2 control, risk of conversion).
Duration: typically 1.5–3 hours (variable with anatomy, shunt/patch, re-do surgery).
Pain: moderate (neck incision); regional provides excellent analgesia; GA requires multimodal analgesia (paracetamol ± low-dose opioid). Avoid heavy opioids that delay neuro assessment.
Key physiological goals: maintain cerebral perfusion, minimise embolic/ischaemic risk, tight haemodynamic control (especially around clamping/unclamping), and rapid post-op neurological assessment.

Indications and patient selection

Symptomatic carotid stenosis (TIA/amaurosis fugax/minor stroke) with significant ipsilateral stenosis: greatest benefit when performed early (often within 2 weeks of symptoms, if safe).
Asymptomatic carotid stenosis: selected high-grade stenosis with low perioperative stroke/death risk and reasonable life expectancy; decision is nuanced and guideline-dependent.
Consider alternatives: carotid artery stenting (CAS) may be preferred in high surgical risk, hostile neck, prior radiotherapy, high lesion, or severe cardiac disease; CAS has different risk profile (more embolic stroke, less MI).

Preoperative assessment and optimisation

Stroke/TIA history: timing, residual deficits, antiplatelets/anticoagulants, imaging (duplex/CTA/MRA), contralateral carotid disease/occlusion (higher clamp risk).
Cardiac risk is major: IHD, heart failure, valvular disease, arrhythmias; CEA patients have high prevalence of coronary disease (MI is important cause of perioperative death).
Blood pressure: treat uncontrolled hypertension; note labile BP common perioperatively due to baroreceptor manipulation.
Respiratory: COPD/OSA; assess ability to tolerate supine neck extension; smoking cessation advice.
Medication management:
- Antiplatelets: aspirin usually continued; dual antiplatelet therapy may be continued depending on surgeon preference and bleeding risk (more common with CAS than CEA).
- Statins: continue; associated with improved outcomes.
- Anticoagulants: manage per indication (AF/VTE/mechanical valve). Plan bridging only if high thrombotic risk; coordinate with surgeon due to neck haematoma risk.
- ACEi/ARB: consider withholding morning of surgery if prone to hypotension; individualise.
Consent/communication: discuss stroke, MI, cranial nerve injury, neck haematoma/airway compromise, need for shunt, and possible ICU/HDU.

Monitoring and access

Standard monitoring + invasive arterial BP (ideally before induction in high-risk or labile BP).
IV access: at least 1 large-bore cannula; consider 2nd IV if difficult access or high risk of haemodynamic instability.
ECG with ST-segment analysis if available; temperature monitoring.
Neuromonitoring options (institution-dependent):
- Awake neurological assessment under regional (gold standard for detecting ischaemia during clamp).
- EEG (detects cortical ischaemia), SSEP, transcranial Doppler (emboli/flow), near-infrared spectroscopy (NIRS; regional saturation trends).
- Carotid stump pressure (surrogate for collateral flow; thresholds vary; limited sensitivity/specificity).
Urinary catheter: selective (long case, renal impairment, tight fluid balance, or if planned HDU/ICU).

Anaesthetic technique: General anaesthesia

Induction: avoid hypotension; titrate propofol/etomidate; consider opioid sparing; vasopressor ready (metaraminol/phenylephrine).
Maintenance: volatile or TIVA; aim for stable haemodynamics and rapid wake-up. Avoid deep anaesthesia causing hypotension; avoid excessive sympathetic responses.
Ventilation: maintain normocapnia (PaCO2 ~4.5–5.5 kPa). Hypercapnia may increase CBF but risks steal and myocardial stress; hypocapnia reduces CBF and may worsen ischaemia.
Neuromuscular blockade: facilitate immobility; ensure full reversal for post-op neuro assessment.
Analgesia: paracetamol ± small opioid doses; local infiltration by surgeon; consider dexmedetomidine as opioid-sparing (watch bradycardia/hypotension). Avoid long-acting sedatives that delay neuro exam.

Anaesthetic technique: Regional anaesthesia

Techniques: superficial cervical plexus block (SCPB) ± deep cervical plexus block (DCPB) or intermediate; ultrasound guidance commonly used.
Sedation: minimal, cooperative patient (e.g., low-dose remifentanil or dexmedetomidine). Maintain airway reflexes; avoid hypercapnia and oversedation.
Advantages: continuous neuro assessment; potentially less haemodynamic instability and shorter LOS in some settings.
Risks/limitations: block failure, patient intolerance, need for urgent conversion to GA, local anaesthetic systemic toxicity (LAST), phrenic nerve palsy, recurrent laryngeal nerve block/hoarseness, inadvertent intravascular/intrathecal injection (esp deep block).
Airway planning: be prepared for rapid conversion (drapes, limited access, neck swelling). Have airway kit, videolaryngoscope, and plan for emergency front-of-neck access.

Haemodynamic targets and key intraoperative phases

General principle: maintain cerebral perfusion pressure while avoiding myocardial ischaemia and haemorrhagic complications.
Before clamp: aim for patient’s normal BP (avoid hypotension). Treat hypertension to reduce myocardial demand and bleeding.
During carotid cross-clamp: commonly target higher MAP (often 10–20% above baseline) to augment collateral cerebral perfusion; individualise based on neuro monitoring and cardiac status.
- If signs of cerebral ischaemia: increase MAP, optimise oxygenation/CO2, consider shunt insertion, deepen anaesthesia only if hypertension is problematic (avoid worsening hypotension).
Unclamping/reperfusion: anticipate hypotension/bradycardia (baroreceptor stimulation) or hypertension; treat promptly. Risk of embolisation and hyperperfusion syndrome.
Post-op: tight BP control is critical (avoid both hypotension causing cerebral hypoperfusion and hypertension causing bleeding/hyperperfusion).

Anticoagulation, antiplatelets, and bleeding

Heparin: given before clamping (dose varies; often 3,000–5,000 IU or weight-based). Confirm timing with surgeon.
Reversal: protamine may be used selectively (bleeding risk vs thrombosis/stroke risk). Local practice varies; discuss with surgeon.
Bleeding/neck haematoma: small volume can cause airway compromise. Maintain meticulous BP control; ensure full haemostasis before extubation.

Emergence, extubation, and postoperative care

Aim: smooth, rapid wake-up for neurological assessment; avoid coughing/straining (risk bleeding) and avoid residual sedation.
Extubation: only when fully awake with intact airway reflexes and haemostasis assured. Consider deep extubation only in very selected cases with low bleeding risk and experienced team (often avoided).
Destination: HDU/ICU or high-dependency recovery with frequent neuro obs and invasive BP monitoring depending on comorbidity and intra-op course.
Post-op analgesia/antiemesis: paracetamol ± small opioid; avoid oversedation; treat PONV to reduce retching/coughing.
Restart antiplatelets/statins as per protocol; manage anticoagulation carefully balancing stroke vs bleeding risk.

Complications (anaesthetic relevance)

Neurological: intra-op cerebral ischaemia (clamp intolerance), embolic stroke, intracerebral haemorrhage (hyperperfusion syndrome).
Cardiac: myocardial ischaemia/infarction, arrhythmias (AF), heart failure exacerbation.
Haemodynamic instability: hypotension/bradycardia (carotid sinus stimulation), hypertension (pain, hypercapnia, withdrawal of antihypertensives, hyperperfusion).
Airway: neck haematoma, laryngeal oedema, recurrent laryngeal nerve palsy (hoarseness/airway obstruction esp if contralateral palsy), hypoglossal nerve injury (tongue deviation).
Cranial nerve injury: VII (mouth droop), IX/X (dysphagia/aspiration), XII (tongue). Usually neuropraxia but can compromise airway/swallow.
Local anaesthetic complications (regional): LAST, phrenic nerve palsy, inadvertent neuraxial spread (high spinal-like picture).

You are asked to anaesthetise a 72-year-old for carotid endarterectomy. What are your key concerns and how will you assess and optimise them preoperatively?

Structure: (1) Neurological disease (2) Cardiac risk (3) BP/meds (4) Airway/respiratory (5) Antithrombotics and plan.

Neurological: timing of TIA/stroke, residual deficits, baseline cognition/speech/limb power; contralateral carotid disease/occlusion; previous CEA/CAS; current antiplatelet therapy.
Cardiac: quantify functional capacity; symptoms of angina/HF; ECG; echo if murmur/HF; manage beta-blockers/statins; consider perioperative troponin/ECG surveillance in high risk.
Blood pressure: document baseline and variability; treat severe hypertension; plan for invasive BP monitoring and vasoactive infusions if labile.
Respiratory/airway: COPD/OSA, aspiration risk, neck mobility (positioning), potential difficult airway; plan for conversion to GA if doing regional.
Antithrombotics: continue aspirin (usually); clarify dual antiplatelets; anticoagulant interruption/bridging plan; discuss bleeding vs stroke risk with surgeon.

Discuss GA versus regional anaesthesia for carotid endarterectomy.

Examiners want balanced pros/cons, monitoring implications, and conversion/airway planning.

Regional advantages: awake neuro monitoring during clamp; may reduce need for shunt; excellent analgesia; potentially less PONV and quicker recovery.
Regional disadvantages: patient anxiety/claustrophobia; movement; block failure; need for urgent conversion with limited access; risks (LAST, phrenic nerve palsy, hoarseness).
GA advantages: secured airway, controlled ventilation/CO2, immobility, easier for long/complex cases or uncooperative patient.
GA disadvantages: indirect neuro monitoring; haemodynamic swings at induction/emergence; risk of delayed neuro assessment if heavy opioids/sedatives used.
Decision: individualise (comorbidity, anatomy, patient preference, team experience). Ensure robust plan for BP control and neurological assessment regardless of technique.

What blood pressure targets would you use during carotid cross-clamping and why?

Goal is to maintain cerebral perfusion through collaterals while avoiding myocardial ischaemia.

Target MAP often 10–20% above the patient’s baseline during clamp (local protocols vary).
Rationale: cross-clamp reduces ipsilateral cerebral perfusion; higher systemic pressure augments collateral flow via Circle of Willis.
If neuro monitoring suggests ischaemia: increase MAP first, optimise oxygenation and normocapnia; request shunt if persistent.
Balance with cardiac risk: avoid excessive hypertension in severe IHD/aortic stenosis; treat myocardial ischaemia promptly.

How would you detect and manage cerebral ischaemia during carotid clamping under GA?

Cover monitoring modalities and a stepwise response.

Detection: EEG changes, SSEP changes, NIRS drop from baseline, TCD reduced flow/emboli, stump pressure low (imperfect).
Immediate actions: increase MAP with vasopressors; ensure adequate oxygenation and haemoglobin; maintain normocapnia; check anaesthetic depth and avoid hypotension.
Communicate with surgeon: consider shunt insertion; check clamp position; minimise clamp time.
Consider embolic cause: if sudden neuro-monitoring change at unclamp, suspect embolus; urgent surgical assessment; maintain BP and oxygenation.

Describe your plan for emergence and extubation after CEA under GA.

Key themes: smooth wake-up, immediate neuro exam, prevent bleeding, manage BP.

Ensure haemostasis and stable BP before wake-up; treat hypertension (e.g., labetalol, glyceryl trinitrate) and avoid hypotension.
Reverse neuromuscular blockade fully; minimise residual sedation; use short-acting agents to allow prompt neuro assessment.
Smooth extubation: lidocaine/short-acting opioid carefully titrated; treat coughing/retching; antiemetics.
Post-extubation: immediate neuro exam (speech, limb power, pupils); monitor for neck swelling/stridor/hoarseness; low threshold for re-exploration if haematoma.

A patient becomes acutely hypertensive and agitated with headache several hours after CEA. What is your differential and management?

This is a classic setup for cerebral hyperperfusion syndrome; also consider stroke, pain, urinary retention, hypoxia/hypercapnia.

Differential: cerebral hyperperfusion syndrome (headache, seizures, focal deficits, intracerebral haemorrhage), ischaemic stroke, pain/anxiety, hypoxia/hypercapnia, bladder distension, drug withdrawal.
Immediate management: ABCs, urgent neuro assessment, check glucose, control BP promptly (titrated IV antihypertensive per local protocol), treat seizures if present.
Escalate: urgent CT brain if neuro symptoms/headache severe; involve stroke/vascular team; consider ICU for tight BP control.

Neck swelling develops in recovery after CEA with stridor. What do you do?

Airway emergency: expanding neck haematoma can obstruct rapidly; act early and call for help.

Call for help immediately (ENT/vascular surgeon, anaesthetic senior, theatre team). Apply high-flow oxygen; sit patient up if tolerated; prepare difficult airway plan.
If airway compromise progressing: proceed to urgent return to theatre for haematoma evacuation; do not delay for imaging.
Airway strategy: rapid sequence induction may be hazardous if anatomy distorted; consider awake fibreoptic if stable; if unstable, proceed with best available technique (videolaryngoscopy) with readiness for emergency front-of-neck access.
If cannot intubate/oxygenate: immediate FONA. If surgeon present and haematoma tense, opening the wound to decompress may temporise oxygenation while definitive airway is secured.

How do you manage bradycardia and hypotension during carotid sinus manipulation?

Common and usually reflex-mediated; treat promptly and coordinate with surgeon.

Ask surgeon to stop manipulation; ensure adequate anaesthetic depth and oxygenation.
Treat bradycardia: atropine or glycopyrrolate; consider ephedrine if hypotensive with bradycardia.
Treat hypotension: vasopressor boluses (metaraminol/phenylephrine) and fluids if appropriate; consider infusion if persistent.
Refractory cases: consider local infiltration of carotid sinus with local anaesthetic by surgeon (practice varies).