[Anesthesia for carotid endarterectomy]

Abstract

Carotid endarterectomy (CE) is among the most common vascular procedures. Recent studies have examined indications for CE and the usefulness of multiple vascular procedures, and have compared general and locoregional anesthesia. Randomized prospective trials have confirmed that the efficacy of CE exceeds 70% in patients experiencing a transient ischemic attack (TIA) with an ipsilateral stenotic carotid lesion. When both carotid surgery and coronary revascularization are indicated, CE can be performed two weeks before or concurrent with coronary artery bypass. The greatest risk in CE is of neurological complications (usually < 6%); the risk of myocardial infarction (MI) is < 4%. General anesthesia is most comfortable for the patient and the surgeon. Barbiturates, opiates and isoflurane are widely employed. Cerebral monitoring involves residual pressure after clamping, although that approach is unreliable. Other forms of hemodynamic (cerebral flow with 133Xe, transcranial Doppler, jugular SvO2, conjunctival PO2) and electrical monitoring (EEG, somatosensory evoked potentials) are often unavailable, are expensive or require trained personnel. Locoregional anesthesia (cervical nerve block or cervical epidural anesthesia) can be monitored more reliably, allows therapeutic maneuvers such as carotid unclamping, placement of an intracarotid stent, increasing of arterial pressure to be carried out. Regional anesthesia decreases the incidence of intraluminal shunts. Blood pressure and heart rate are higher during cervical block than during general anesthesia, but hypertension is more common during general anesthesia. A randomized controlled trial comparing general anesthesia and cervical block found no significant differences in mortality, MI or TIA. Regional anesthesia is more cost-effective, given that less intensive care and shorter hospital stays are required.