Pro: Regional anesthesia is the best technique for carotid endarterectomy

Abstract

HE ASSERTION that regional anesthesia is superior to general anesthesia for carotid endarterectomy (CEA) was first made in this journal by Dr John Youngberg in a Pro/Con debate appearing in October 1987.1.2 At that time, little outcome data were available to support any conclusion on anesthetic technique. Accordingly, Dr Youngberg based his argument on the potential benefit of regional anesthesia for CEA. His paper stressed the theoretical advantage of monitoring an awake patient for new neurologic deficits compared with the inaccuracies of cerebral monitoring in an anesthetized patient. In an awake patient, intra-arterial shunts are placed when indicated by patient assessment. Therefore, shunt use (and the associated risks of dissection, thrombus formation, or atheromatous embolism and resulting neurologic deficits) could be reduced in patients with regional anesthesia. Further, neurologic and myocardial outcomes could be improved by avoiding the deleterious effects of general anesthesia on cerebral and myocardial blood flows. Finally, he speculated that regional anesthesia would allow quicker postoperative recovery, and sholxer intensive care unit and hospital lengths of stay. Despite these persuasive arguments, Dr Youngherg cited only one study that directly compared outcome in patients having regio~Lal versus general anesthesia, 3 and, therefore, his conclusions remained only speculation. Since the publication of that first Pro/Con debate, several authors have published outcome data comparing regional with general anesthesia for CEA, prompting this return to the issue. Specifically, a Medline search of the literature reveals 13 papers that compare outcome in a total of 7,619 patients having either regional or general anesthesia for CEA (Table 1). The data are now available with which to reevaluate Dr Youngberg's assertion that regional anesthesia is superior to general anesthesia for CEA. For these purposes, primary outcome will be defined as the incidence of postoperative transient ischemic attack (TIA), stroke, myocardial infarction (MI), and death. Secondary outcomes will include the incidence of shunt placement, hospital and intensive care unit lengths of stay, hospital charges, postoperative hemodynamic stability, and use of vasoactive agents. In addition, information on the reliability of central nervous system monitoring during general anesthesia, and the incidence of failed regional anesthesia will be reviewed. These outcome data clearly show that regional anesthesia improves primary and secondary outcomes, that regional anesthesia permits superior neurologic monitoring, and that the incidence of failed blocks is low. Table 1 presents primary outcome in 13 studies 3-15 tiaat specifically evaluate regional versus general anesthesia for CEA. Two of these studies report data from prospective trials, s,13 whereas the remainder are retrospective reviews. Three of these studies 11,12,15 show a significant improvement in primary outcome with regional anesthesia and deserve special comment. Allen et al v report on 679 consecutive CEAs in 584 patients. MI occurred in nine patients in the general anesthesia greup (2.5%) and in two patients in the regional anesthesia greup (0.6%), p = 0.07. Cardiopulmonary complications occurred in 30 operations (8.3%) performed under general anesthesia, and in only 13 (4.1%) operations with cervical block, p = 0.03. Becquemin et a112 retrospectively studied a series of 385 CEAs and found 10 MIs documented by electrocardiogram or cardiac enzyme changes in the general anesthesia group, and no MIs in the regional anesthesia group, p < 0.05. Five of these 10 MIs were fatal. They concluded that regional anesthesia by cervical