Endarterectomy

Endarterectomy is the surgical removal of an atherosclerotic plaque together with the diseased intima and inner media through an arteriotomy, leaving the outer media and adventitia as the new luminal surface. Carotid endarterectomy is the most frequently performed procedure. The technique is also used in the common femoral and profunda femoris arteries, the aortoiliac segment, and the renal, visceral and coronary arteries.

Key anatomy for the carotid procedure

• The common carotid artery divides at the level of the upper border of the thyroid cartilage (C3 to C4).
• Structures encountered are the facial vein, the hypoglossal nerve crossing the internal carotid artery superiorly, the ansa cervicalis, the vagus nerve (posterolateral within the carotid sheath), the superior laryngeal nerve, the marginal mandibular branch of the facial nerve, and the carotid sinus nerve.

Indications for carotid endarterectomy

• Symptomatic stenosis of 70 to 99%, and selected patients with 50 to 69%.
• Asymptomatic stenosis of 60 to 99% in carefully selected patients with a life expectancy over 5 years and a low centre complication rate.
• Timing: within 2 weeks of the index event for symptomatic stenosis.

Indications for other sites

• Common femoral: disease involving the common femoral bifurcation. Endarterectomy with patch angioplasty has durable results and is preferred over stenting at this site.
• Aortoiliac: focal disease in selected patients, or when stenting is unsuitable.
• Renal and mesenteric: rare, in combination with aortic reconstruction.
• Coronary: rare, as an adjunct during bypass for diffuse disease.

Operative techniques for carotid disease

• Conventional: longitudinal arteriotomy from common carotid to internal carotid, endarterectomy, and closure with a patch of vein, bovine pericardium or polyester. Patching reduces perioperative stroke and restenosis.
• Eversion: the internal carotid is transected at the bifurcation, everted over the plaque and reimplanted. It avoids a patch and has short operating time.
• Shunt policy: routine, selective (guided by stump pressure, EEG or transcranial Doppler) or none. A stump pressure above 40 to 50 mmHg usually permits clamping without a shunt.
• Anaesthesia: general or regional (cervical plexus block) are equivalent for stroke and death outcomes. Regional allows continuous neurological monitoring.

Clinical considerations in operative candidates

• Symptomatic patients present with TIA, amaurosis fugax or minor stroke ipsilateral to the stenosis.
• Factors increasing surgical risk are age over 80, severe coronary disease, contralateral carotid occlusion, previous neck surgery or radiotherapy, high carotid bifurcation, tandem intracranial stenosis, uncontrolled hypertension and renal failure.

Postoperative events

• Stroke or death: 2 to 3% in symptomatic and under 2% in asymptomatic patients at good centres. Early strokes are usually embolic, from clamping or thrombosis of the endarterectomy surface, and late strokes relate to restenosis.
• Myocardial infarction: 1 to 2%, and a major driver of long term mortality.
• Neck haematoma: in 1 to 3%, presenting with swelling, stridor, dysphagia and tracheal deviation. It is an airway emergency.
• Cranial and cervical nerve injury: transient in 5 to 10% and permanent in 1 to 2%.
• Hypoglossal: tongue deviation to the side of injury.
• Vagus or recurrent laryngeal: hoarseness and aspiration.
• Superior laryngeal: voice fatigue and loss of high pitch.
• Marginal mandibular: lower lip asymmetry when smiling.
• Greater auricular: numbness of the ear lobe.
• Hyperperfusion syndrome: in 1 to 3%, typically on days 2 to 7, with ipsilateral headache, seizures, focal deficit and intracerebral haemorrhage. Risk factors are severe stenosis, contralateral occlusion, poor collaterals and postoperative hypertension.
• Baroreceptor dysfunction: hypotension and bradycardia early, and labile hypertension.
• Wound infection or patch infection: under 1%, which can lead to pseudoaneurysm.
• Restenosis: 5 to 10% at 2 years, mostly from intimal hyperplasia within the first 2 years. Late recurrence reflects new atherosclerosis.

Complications of femoral endarterectomy: wound infection or lymphocele (up to 10 to 20% in the groin), seroma, haematoma, and thrombosis of the repair.

Preoperative evaluation

• Duplex ultrasound and CT angiography (or MR angiography) from arch to circle of Willis, to confirm stenosis grade, define bifurcation height, and exclude tandem lesions.
• Brain imaging (MRI with diffusion or CT) to document the symptomatic infarct, and exclude a large recent infarct or haemorrhagic transformation. Surgery within 2 weeks is preferred for small infarcts, with delay for large infarcts.
• Cardiac assessment: ECG and risk stratification, with echocardiography and stress testing when indicated. Revascularise severe coronary disease according to usual indications rather than routinely before carotid surgery.
• Laboratory tests: CBC, coagulation screen, creatinine, glucose and HbA1c, lipids, and group and save.
• Rhythm monitoring for atrial fibrillation in patients who present with stroke.
• Medication review, with documentation of antiplatelet and statin use.

Intraoperative monitoring

• Continuous arterial pressure monitoring, EEG, transcranial Doppler or awake neurological testing under regional anaesthesia.
• Completion duplex or angiography to identify residual defects, kinks or intimal flaps.

Postoperative surveillance

• Neurological observation every 15 minutes for the first hour, then hourly.
• Immediate imaging for new deficits, with return to the operating room if the artery is thrombosed or there is a technical defect.
• Carotid duplex at 1 month, 6 months and then annually.

Preoperative medical optimisation

• Continue aspirin 75 to 100 mg daily without interruption. For patients on dual antiplatelet therapy after a recent stroke or TIA, continue both agents through surgery where the surgeon accepts the bleeding risk.
• Atorvastatin 40 to 80 mg daily, started before surgery and continued lifelong.
• Control blood pressure to below 160/90 mmHg before surgery, and continue beta blockers in those already taking them.
• Cefazolin 2 g IV within 60 minutes before the incision (3 g for weight over 120 kg).

Intraoperative care

• Unfractionated heparin 5,000 units IV (about 70 to 100 units/kg) before clamping, aiming for an activated clotting time of 250 to 300 seconds. Protamine 1 mg per 100 units of heparin can reverse the effect at the end if bleeding is a concern.
• Maintain blood pressure at the upper normal range during clamping, using phenylephrine 50 to 100 micrograms bolus when needed, to maximise collateral flow.
• Local anaesthetic infiltration around the carotid bifurcation (lidocaine 1%, 2 to 3 mL) to reduce baroreceptor reflex responses.
• Meticulous haemostasis, and a drain at the surgeon's discretion.

Postoperative management

• Admit to a high-dependency unit or recovery area with neurological monitoring.
• Blood pressure: systolic 100 to 140 mmHg. Treat hypertension with labetalol 10 to 20 mg IV bolus, or nicardipine infusion 5 to 15 mg/h. For hypotension, use fluids and phenylephrine, and review for myocardial ischaemia.
• Antiplatelets: aspirin 75 to 100 mg daily lifelong, with clopidogrel 75 mg for 1 to 3 months in selected patients.
• Statin and risk factor control continue indefinitely.
• Early discharge is often possible on day 1 or 2.

Management of complications

• Neck haematoma with airway threat: open the wound at the bedside, evacuate, and secure the airway. Intubation may be difficult, so call for expert airway help early. Return to theatre for control.
• Postoperative neurological deficit: immediate duplex or CT angiography and brain imaging. Re-explore if thrombosis or a technical defect is present. Thrombectomy is an option for downstream occlusion.
• Hyperperfusion syndrome: strict control of systolic pressure below 140 mmHg (and below 120 mmHg if symptoms or haemorrhage), antiseizure medication such as levetiracetam 500 to 1,000 mg twice daily if seizures occur, and avoidance of anticoagulation.
• Cranial nerve palsies: most recover within 6 weeks to 6 months. Speech therapy, swallowing assessment and vocal fold injection for persistent laryngeal nerve palsy.
• Restenosis: reintervention for symptomatic or progressive severe restenosis, preferably by stenting, as redo surgery carries higher cranial nerve and stroke risk.
• Patch infection: debridement, culture-directed antibiotics, and bypass or patch replacement.

Other endarterectomy sites

• Common femoral: longitudinal arteriotomy extending onto the profunda, plaque removal, and patch closure. Combine with endovascular treatment of the superficial femoral artery in hybrid procedures. Aspirin 75 to 100 mg daily and a statin follow, with duplex at 1, 6 and 12 months.
• Aortoiliac: reserved for focal disease and selected young patients. Heparinise at 100 units/kg and clamp carefully.
• Technique-related groin complications: keep skin closure meticulous and use sartorius muscle flap cover in high-risk wounds. Antibiotic prophylaxis for 24 hours.