Carotid Surgery. Anesthetic considerations Sam Hemans MD DDS Charles Smith MD 3 August 2004. Objectives. Pathophysiology of carotid dz Strategy for anesthetic evaluation Perioperative management Complications New therapies in the field. Epidemiology.
Sam Hemans MD DDS
Charles Smith MD
3 August 2004
Surgical- placement of a shunt during x-clamp
Physiologic: Mild hypothermia 33-34C
Maintenance of normocarbia
Anesthetic:Barbiturates, no evidence for permanent focal deficits
volatile anesthetics, iso and sevo associated with lower critical bf
c/w halothane and enflurane
Etomidate shown to worsen outcome in animal models,thio
shown to improve ischemic injury
Propofol , animal studies have produced mixed results
Stroke, usually embolic
Cranial Nerve injury, occurs in 10% of patients
The most commonly injured nerves are,hypoglossal nerve,vagus, recurrent laryngeal,accessory nerve.
Unilateral damage usually no immediate sx or intervention
Bilateral damage could result in upper airway obstruction
Beware of patients with pre-existing neck surgeryPost- op
One of the more difficult decision matrices
regards the patient who presents with simultaneous dz of the carotid and the coronary vessels
Best available evidence – doubling of risk of death or stroke if performed as a single
anesthetic as opposed to a staged procedure
In a staged procedure risk is related to which procedure is performed first: If CEA is performed first the risk of mi increases; if CABG is performed first the risk of stroke increases
Pre-op concerns, uncotrolled htn
Anesthetic technique no demonstrated advantage of regional vrs general
Cerebral Monitoring, neurologic status in the awake patient, and the EEG may be considered close to the gold standard
Post op concerns, usually due to htn
Whichever anesthetic method is chosen, it is imperative that CBF be optimized, with min cardiac stress especially during x-clamping.
The risk of ischemia may be decreased by maintaining normal to high perfusion pressureSummary
Drawbacks, profound bradycardia, high incidence of strokes from the angiography alone.
SAPPHIRE (Stenting and Angioplasty with Protection at High-Risk for Endarterectomy)
First randomized trial to evaluate the safety and efficacy of carotid artery stenting with emboli prevention in high surgical risk patients.
High risk criteria included, prior cea, neck surgery, radiation to the neck, occlusion of the contralateral carotids, chf and other confounding medical problemsNew Therapies
Enrollment terminated after 723 patients were enrolled, 416 registry and 307 randomized, as interim analysis showed a marked benefit in favour of stenting. Success defined as <30% residual stenosis
30 day periprocedural combined stroke/mi/death rate which was the study endpoint was 5.8% in the stent group but 12.6% in the surgical group
Showed that in high risk patients CAS was a superior to CEA and that emboli prevention was also improved in the CAS group of patients.conclusion