Oral Board Case: Carotid Artery Stenosis

How do you interpret this presentation, and what is your differential for the transient neurologic episodes?

Expected answer

This is a classic TIA presentation—transient left-sided weakness and dysarthria that resolve completely. Left-sided symptoms localize to the RIGHT hemisphere, which matches the right carotid bruit, suggesting right (ipsilateral to the lesion) carotid embolic source. Differential includes carotid atheroembolism, cardioembolic source (AF, valvular disease), small-vessel/lacunar disease, intracranial stenosis, and non-vascular mimics like seizure, hypoglycemia, or migraine. The bruit and risk factors (HTN, hyperlipidemia, smoking) point strongly to extracranial carotid disease.

What does your initial workup include?

Expected answer

Complete neurologic, cardiac, neck, and ocular exam. Look for pronator drift, cranial nerve deficits, Hollenhorst plaques on funduscopy, and a cardiac arrhythmia or murmur. Obtain carotid duplex ultrasound as first-line imaging to quantify stenosis (elevated peak systolic and diastolic velocities, spectral broadening). Get an ECG and consider echocardiography and rhythm monitoring to exclude a cardiac source. Obtain brain imaging (CT or MRI) to confirm there is no completed infarct or hemorrhage. Standard labs including lipid panel and HbA1c.

Duplex shows 75% stenosis of the right internal carotid artery. Is this patient a surgical candidate, and why?

Expected answer

Yes. He is symptomatic with ipsilateral stenosis >50%, which is an indication for revascularization. NASCET demonstrated that in symptomatic patients with >70% stenosis, CEA reduced stroke risk from 26% to 9%. He should also be started on best medical therapy—antiplatelet agent, high-intensity statin, blood pressure control, and smoking cessation—and offered carotid endarterectomy.

What confirmatory imaging would you obtain before operating, if any, and what's the timing of surgery?

Expected answer

Duplex is usually sufficient, but I would corroborate the stenosis with a second modality (CTA or MRA) before operating, particularly if surgical planning or duplex quality is in question, to confirm degree of stenosis and assess the arch and intracranial vessels. For a symptomatic patient with a recent TIA and no large infarct, CEA is best performed within 2 weeks of symptom onset for maximal stroke-prevention benefit, but not within the first 48 hours of an acute disabling stroke.

Why would you choose CEA over carotid artery stenting (CAS) in this patient?

Expected answer

CEA is the preferred treatment for suitable candidates. The CREST trial showed CEA had a lower combined stroke/death risk (4.7%) compared to CAS (6.4%), and periprocedural stroke risk favors CEA, especially in older patients (>70). CAS is reserved for high-risk-for-CEA patients: prior neck irradiation, prior carotid/neck surgery, hostile neck, lesions surgically inaccessible (high or very proximal), or those unfit for general anesthesia. This 72-year-old has no contraindication to CEA, so CEA is the better choice.

During CEA, how do you decide whether to place a shunt?

Expected answer

A shunt maintains cerebral perfusion during carotid cross-clamping. Indications include EEG changes consistent with cerebral ischemia, neurologic deterioration if done under local/regional anesthesia (awake monitoring), or carotid stump (back) pressure below 50 mmHg. Some surgeons shunt routinely. Selective shunting based on monitoring avoids the risks of shunt placement (embolization, intimal injury) in patients with adequate collateral flow.

What are the principal complications of CEA, and how do you recognize and manage them?

Expected answer

Key complications are perioperative stroke (from embolization, clamping, or postoperative thrombosis/flap), cranial nerve injuries (hypoglossal—tongue deviation, vagus/recurrent laryngeal—hoarseness, marginal mandibular—lip asymmetry), neck hematoma with airway compromise, and hyperperfusion syndrome (headache, seizures, hemorrhage—manage with strict BP control). A new neurologic deficit in the immediate postoperative period mandates urgent evaluation for carotid occlusion/thrombosis and prompt return to the OR for re-exploration. An expanding neck hematoma threatening the airway requires immediate bedside opening of the incision and airway control.

What postoperative care and long-term follow-up does this patient need?

Expected answer

Continue antiplatelet therapy, high-intensity statin, blood pressure control, and aggressive risk-factor modification including smoking cessation. Tight perioperative BP control reduces hyperperfusion risk. Surveillance carotid duplex is typically performed at 6 weeks and 6 months to assess the operated vessel for restenosis and to monitor the contralateral carotid; most surgeons recommend lifelong duplex surveillance.

If this same stenosis were found incidentally in an asymptomatic patient, would you still operate?

Expected answer

Not at the 50% threshold. For asymptomatic patients, intervention is generally recommended only for stenosis >80% (with reasonable life expectancy and acceptable surgical risk), since the benefit margin over best medical therapy is narrower. Asymptomatic patients otherwise warrant optimized medical therapy and surveillance. This patient's symptomatic status is what lowers his treatment threshold to >50%.