Carotid endarterectomy

Carotid endarterectomy

Anesthesia type	GETA vs. regional anesthesia
Airway	Endotracheal Tube
Lines and access	PIV x 2 18 ga or larger is adequate
Monitors	Standard monitors, arterial line
Primary anesthetic considerations
Preoperative
Intraoperative
Postoperative
Article quality
Editor rating	Comprehensive
User likes	2

Carotid endarterectomy (CEA) is a surgical procedure for treating occlusive atherosclerotic disease involving the common and internal carotid arteries. The procedure is more effective than medical management for patients with high grade stenosis (70–99%), symptomatic moderate stenosis (50-69%), or asymptomatic high-grade stenosis (≥ 60%). CEA involves making a longitudinal incision along the anterior border of the sternocleidomastoid muscle to expose the common, internal, and external carotid arteries as well as the carotid sinus. The carotid artery is then opened and the atherosclerotic plaque is removed. Opening of the carotid artery requires occlusion of the proximal common carotid and distal internal and external carotid arteries, which requires adequate collateral flow from the contralateral common carotid artery or placement of an internal shunt between the proximal common carotid and the distal internal carotid arteries. On removal of the atherosclerotic plaque, the media and adventitia of the arteries may be re-approximated or a graft may be used. These grafts are typically synthetic, but vein grafts are occasionally used.

Preoperative management

Patient evaluation

System	Considerations
Neurologic	Evaluate plaque location and adequacy of collateral flow with carotid angiograms prior to surgery
Cardiovascular	Preoperative ECG is useful as perioperative MI is the most common major postoperative complication. Uncontrolled hypertension or diabetes, as well as recent MI are reasons to delay the case.
Respiratory	ABGs, Spirometry, and CXRs are useful only if otherwise indicated from the H&P
Hematologic	Anti-platelet agents (typically aspirin) are typically initiated preoperatively and continued until the day of surgery to prevent perioperative thromboembolic complications.

Patient preparation and premedication

Premedication in CEA may complicate the immediate postoperative evaluation for stroke or TIA. Use of preoperative benzodiazepines and opioids should be limited. If a discussion of the operation and safety steps is inadequate to alleviate the patient's fear, a small dose of midazolam is preferred to opioid premedication.

Regional and neuraxial techniques

• Superficial cervical plexus blocks + supplemental field blocks by surgeon
• Deep cervical plexus blocks are now avoided due to concomitant Horner's Syndrome, phrenic nerve block, and recurrent laryngeal nerve injuries
• Patients receiving regional anesthesia for CEA have decreased ICU times and may have decreased need for surgical shunts. Regional anesthesia for CEA, however, does not provide cerebral protection afforded by general anesthesia and it makes conversion to GETA more challenging should the need arise.

Intraoperative management

Monitoring and access

• Standard ASA monitors
• Arterial line allows prompt vasopressor titration in response to changes in blood pressure, particularly if induced-hypertension is being used during carotid clamping.
  • Invasive blood pressure monitoring is particularly useful during the immediate postoperative period to monitor for cerebral hyperperfusion syndrome.

• EEG monitoring, somatosensory evoked potentials (SSEPs), and motor evoked potentials (MEPs) may be used to assess cerebral perfusion.

Induction and airway management

If general anesthesia is chosen, endotracheal intubation is preferred over placing an LMA. Choice of induction medications is dependent on patient comorbidies, but caution should be used with ketamine as it increases CMRO2 at a time when cerebral blood flow is limited.

For patients undergoing regional anesthesia light sedation with midazolam, fentanyl, propofol, or dexmedetomidine is reasonable. Avoid heavy sedation as patient cooperation may be required for neurologic exam.

Positioning

Patients are positioned supine with the head turned away from operative site. Beach chair may be used for comfort in awake patients

Maintenance and surgical considerations

Volatile anesthetics supplemented with opioids for analgesia and neuromuscular blockade is adequate for CEA without electrophysiologic monitoring (EP). For patients receiving EP monitoring, a total IV anesthetic with propofol and remifentanil provides excellent sedation and operating conditions.

Heparin is required prior to carotid cross-clamping. The ACT goal is 200-250 seconds.

Carotid cross clamping may induce a severe vagal response with bradycardia and hypotension. Local anesthetic infiltration by the surgeon prior to cross clamping may improve this response.

Unclamping can produce a reflex bradycardia and vasodilation effect

Blood Pressure Maintenance

MAPs should be kept at or above the patient's awake MAP. A phenylephrine drip is a good choice because it's pure α-1 activity decreases the risk of arrhythmias. Wide swings in blood pressure should be expected during CEA. Sudden bradycardia may occur with associated hemodynamic instability, so atropine of glycopyrrolate should be available.

Emergence

• Many surgeons prefer to verify neurologic status prior to extubation
• Use caution to avoid coughing and bucking which can lead to neck hematoma formation, hypertension, and even hemorrhagic stroke during emergence

Postoperative management

Potential complications

Neurologic deficits may surface after emboli from plaque or shunts or from hypoperfusion during the procedure

Plaque removal during surgery may cause baroreceptor changes causing either hypotension or hypertension requiring vasoactive medications in the recovery unit

Procedure variants

	Variant 1	Variant 2
Unique considerations
Position
Surgical time
EBL
Postoperative disposition
Pain management
Potential complications