A comparison of regional and general anesthesia in patients undergoing carotid endarterectomy

Purpose: The optimal anesthetic for use during carotid endarterectomy is controversial. Advocates of regional anesthesia suggest that it may reduce the incidence of perioperative complications in addition to decreasing operative time and hospital costs. To determine whether the anesthetic method correlated with the outcome of the operation, a retrospective review of 3975 carotid operations performed over a 32-year period was performed.Methods: The records of all patients who underwent carotid endarterectomy at our institution from 1962 to 1994 were retrospectively reviewed. Operations performed with the patient under regional anesthesia were compared with those performed with the patient under general anesthesia with respect to preoperative risk factors and perioperative complications.Results: Regional anesthesia was used in 3382 operations (85.1%). There were no significant differences in the age, gender ratio, or the rates of concomitant medical illnesses between the two patient populations. The frequency of perioperative stroke in the series was 2.2%; that of myocardial infarction, 1.7%; and that of perioperative death, 1.5%. There were no statistically significant differences in the frequency of perioperative stroke, myocardial infarction, or death on the basis of anesthetic technique. A trend toward higher frequencies of perioperative stroke (3.2% vs 2.0%) and perioperative death (2.0% vs 1.4%) in the general anesthesia group was noted. In examining operative indications, however, there was a significant increase in the percentage of patients receiving general anesthesia who had sustained preoperative strokes when compared with the regional anesthesia patients (36.1% vs 26.4%; p < 0.01). There was also a statistically significant higher frequency of contralateral total occlusion in the general anesthesia group (21.8% vs 15.4%; p = 0.001). The trend toward increased perioperative strokes in the general anesthesia group may be explicable either by the above differences in the patient populations or by actual differences based on anesthetic technique that favor regional anesthesia.Conclusions: In a retrospective review of a large series of carotid operations, regional anesthesia was shown to be applicable to the vast majority of patients with good clinical outcome. Although the advantages over general anesthesia are perhaps small, the versatility and safety of the technique is sufficient reason for vascular surgeons to include it in their armamentarium of surgical skills. Considering that carotid endarterectomy is a procedure in which complication rates are exceedingly low, a rigidly controlled, prospective randomized trial may be required to accurately assess these differences. (J Vasc Surg 1996;24;946-56.)     

Comparison of regional and general anesthesia for carotid endarterectomy

Two hundred twenty-one patients undergoing carotid endarterectomy were studied for morbidity and mortality. Thirty-seven had general anesthesia and 138 had regional anesthesia. The two groups were similar in preoperative risk factors and were operated on by a single surgeon and similar operative teams. Patient selection was prospective in the sense that the first 37 procedures were performed with general anesthesia and the next 184, with regional anesthesia. No significant difference in incidences of death, myocardial infarction, stroke, or transient ischemic attack was found. Hospital lengths of stay were similar. The type of anesthetic used for carotid endarterectomy should be the choice of the surgeon and operative team.     

Computerized electroencephalographic monitoring and selective shunting: influence on intraoperative administration of phenylephrine and myocardial infarction after general anesthesia for carotid endarterectomy.

During carotid endarterectomy (CEA), phenylephrine infusions are commonly used to induce hypertension during carotid clamping in an attempt to increase collateral cerebral blood flow and prevent cerebral ischemia. Although this practice appears to increase the incidence of intraoperative myocardial ischemia during CEA when general anesthesia is employed, whether the limited use of phenylephrine infusions in specific instances of cerebral ischemia, as shown on an electro-encephalogram, results in low perioperative rates of both myocardial infarction (MI) and cerebral infarction remains unclear. We studied 171 CEAs done under general anesthesia performed with selective shunting based on the identification of cerebral ischemia by a two-channel computerized electroencephalographic monitor. The use of a phenylephrine infusion was restricted to the following instances of cerebral ischemia: 1) ischemia associated with hypotension that did not resolve within 2 minutes of decreases in anesthetic administration and treatment with fluid and/or colloid; 2) ischemia poorly or slowly responsive to shunt placement, accompanied by either hypo- or normotension; and 3) ischemia poorly or slowly responsive to removal of the carotid clamp, accompanied by either hypo- or normotension. Two non-Q wave MIs (1.2%) occurred, both nonfatal. There were two cerebral infarctions (1.2%) and three deaths not related to MI (1.8%). Based on these findings, in order to decrease the incidence of both MI and cerebral infarction after general anesthesia for CEA, we recommend the restrictive use of phenylephrine-induced hypertension for specific instances of slowly or poorly reversible cerebral ischemia, as shown on the electroencephalogram.     

Anästhesie zur Karotischirurgie

Carotid endarterectomy (CEA) has remained the first choice of treatment in preventing ischemic stroke due to symptomatic stenosis of the internal carotid artery despite other new available options. During CEA patients are first and foremost at risk of cerebral as well as myocardial ischemia, therefore, maintenance of the oxygen supply to the brain and the myocardium is of outstanding importance requiring reliable monitoring of cerebral and cardiac function. The regional versus general anesthesia debate is an age-old one that has brought few definite answers regarding the impact on postoperative outcome of either anesthetic technique. Up to now, there is little evidence from only a few randomized clinical trials to demonstrate the superiority of either anesthetic technique with respect to outcome parameters. Because the level of evidence in favor of regional anesthesia during CEA can at least be rated between 1(-) and 2(+) the resulting recommendation is grade C. The purpose of the review is to highlight the characteristics and goals of anesthetic management during CEA.     

Carotid endarterectomy under regional (conductive) anesthesia.

Carotid endarterectomy is reliable in the prevention of strokes due to arteriosclerotic disease at the carotid bifurcation. This is a retrospective review of 314 carotid endarterectomies performed at the University Health Center of Pittsburgh. The objectives of the study were to determine if regional anesthesia was a safe technique for carotid endarterectomy and to determine whether the neurologic complications that occurred were embolic or ischemic in origin. In patients who were neurologically intact before operation, the perioperative mortality was 0.88% and the incidence of neurologic complications was 3.1%. This is comparable to the current literature. Observations of the awake patient suggested that half the neurologic deficits that occurred in this series were due to embolization rather than to cerebral ischemia. Further more, the incidence of non-neurologic complications under general anesthesia was 12.9%. Under regional anesthesia, the incidence of non-neurologic complications was 2.8%. The data supports carotid endarterectomy under regional block as safe and reliable method.     

Clinical outcomes after carotid endarterectomy: comparison of the use of regional and general anesthetics

OBJECT: The authors analyzed their series of carotid endarterectomies (CEAs), which were performed after administration of either a general or regional anesthetic, to determine whether the choice of anesthetic affected patients' clinical outcomes and length of hospital stay. METHODS: A series of 803 consecutive CEAs performed between July 1990 and February 1999 was reviewed. Cases were analyzed for patient demographics, comorbid medical states, and perioperative complications. Contingency-table statistical analysis was used to compare the incidence of comorbid medical states and perioperative complications between patients who underwent CEA in which either a regional or general anesthetic was used. Student's t-test was used to compare the length of hospital stay and mean patient age. A regional anesthetic was used for 632 CEAs, and a general anesthetic was used for 171 operations. There were no statistically significant intergroup differences in demographics or comorbid medical states. The incidence of perioperative stroke and death did not differ significantly between the regional (2.7%) and the general anesthetic groups (2.3%). However, the incidence of nonneurological, nonfatal complications was significantly less in the regional anesthetic (1.6%) than in the general anesthetic group (14.6%, p<0.0001). Patients undergoing CEA in which a regional anesthetic was used had a significantly lower incidence of cardiopulmonary complications (myocardial infarction and postoperative intubation), cervical complications (neck hematomas and cranial nerve injuries), and urological complications (urinary retention) than patients who underwent surgery after receiving a general anesthetic. CONCLUSIONS: Patients undergoing CEA in which a regional anesthetic was used had significantly fewer nonneurological, nonfatal complications, particularly cardiopulmonary complications, than similar patients surgically treated after induction of general anesthesia.     

Perioperative strokes after 1001 consecutive carotid endarterectomy procedures without an electroencephalogram: incidence, mechanism, and recovery

HYPOTHESIS: That alternative methods of cerebral protection, especially routine shunting of all patients undergoing general anesthesia or shunting on the basis of neurologic assessment with the patient awake under cervical plexus block, result in outcomes of carotid endarterectomy comparable with those reported using electroencephalographic monitoring. DESIGN: Retrospective review of cases from a vascular registry established in 1990. SETTING: Tertiary care center. PATIENTS: Consecutive sample of 1001 patients who underwent carotid endarterectomy. INTERVENTIONS: Carotid endarterectomy procedures were performed without electroencephalographic monitoring, using general anesthesia with routine shunting or using regional anesthesia. MAIN OUTCOME MEASURES: Overall stroke and mortality rates and cause and consequence of the postoperative strokes. RESULTS: There were 14 nonfatal strokes (1.4%) and 2 deaths (0.2%), for a combined stroke and death rate of 1.6%. Nine (64%) of the 14 strokes appeared to result from a technical error during the endarterectomy. Mild deficits were noted after 7 strokes (50%), with the remainder resulting in deficits that required inpatient rehabilitation. Twelve patients with strokes (86%) eventually returned home without need for assistance. CONCLUSIONS: Most postoperative strokes in this series were due to technical errors. Overall, even in patients with strokes initially requiring inpatient rehabilitation, there was good recovery of function. Low stroke and mortality rates can be achieved in carotid endarterectomy without the use of electroencephalographic monitoring.     

The influence of anesthetic technique on perioperative blood pressure control after carotid endarterectomy

The optimal anesthetic for use during carotid endarterectomy has been a matter of debate for three decades. The goal of this study is to evaluate the influence of anesthetic technique on perioperative hemodynamic instability after carotid endarterectomy. This study is a retrospective chart review and was performed in a community teaching hospital. All consecutive patients undergoing carotid endarterectomy over a 2-year period at Providence Hospital were reviewed. One hundred ninety-eight patients underwent 203 carotid endarterectomies. Two patients were excluded because of combined coronary artery bypass grafting. Patients underwent carotid endarterectomy and were divided into two groups on the basis of use of general or regional anesthesia. Blood pressure was recorded hourly for the subsequent 24 hours, and the doses of vasoactive medications received to maintain the blood pressure within 25 mm Hg of preoperative levels were recorded. Patients receiving general anesthesia were found to require significantly more sodium nitroprusside for control of hypertension compared with those receiving regional anesthesia (72.1 +/- 14.5 microg/kg vs 20.2 +/- 6.6 microg/kg; P = 0.001) in the first 8 postoperative hours. No significant differences were noted in the doses of any other vasoactive medications used. No differences were found in the subsequent 16-hour period in doses of vasoactive medications. Patients suffering myocardial infarctions were found to receive higher doses of nitroglycerine, but no differences were noted in any other vasoactive medication used based on complications. Length of stay was longer in the general anesthesia group compared with the regional anesthesia group for both the intensive care unit (1.59 +/- 0.13 days vs 1.08 +/- 0.03 days; P = 0.001) and total hospital stay (5.8 +/- 0.03 days vs 4.5 +/- 0.02 days; P = 0.003). Regional anesthesia required lower doses of antihypertensive medication in the early postoperative period when compared with general anesthesia. The doses of vasoactive medications used had no significant impact on the complication rate. Regional anesthesia allowed for shorter stay in both the intensive care unit and total hospital stay.     

The influence of anesthetic technique on perioperative complications after carotid endarterectomy

Purpose: This study evaluated the influence of anesthetic techniques on perioperative complications after carotid endarterectomy.Methods: Perioperative complications, the use of a carotid artery shunt, the duration of the operative procedure and postoperative hospital course were retrospectively compared in 584 consecutive patients undergoing 679 carotid endarterectomies with use of either general anesthesia (n = 361) or cervical block regional anesthesia (n = 318). There was no significant difference in the preoperative medical characteristics between the two anesthetic groups. Symptomatic carotid artery disease was the indication for surgery in 247 (68.4%) patients receiving general anesthetics, whereas 180 (56.6%) patients treated with a cervical block anesthetic had a symptomatic carotid artery stenosis (p = 0.02).Results: The perioperative stroke rate and stroke-death rate for the entire series was 2.4% and 3.2%, respectively, and was not significantly different between the anesthetic groups or between patients with symptomatic or asymptomatic disease. A carotid artery shunt was used in 61 (19.2%) patients receiving a cervical block anesthetic and 152 (42.1%) patients treated with a general anesthetic (p < 0.0001). Use of cervical block anesthesia was associated with a significantly shorter operative time, fewer perioperative cardiopulmonary complications, and a shorter postoperative hospitalization when compared with general anesthesia. Multivariate risk factor analysis indicated that age greater than 75 years, operative time greater than 3 hours, and the use of a carotid artery shunt were all independent risk factors for perioperative cardiopulmonary complications. When a carotid artery shunt was not analyzed as a multivariate risk factor, then general anesthesia became a significant risk factor for perioperative cardiopulmonary complications (risk ratio 2.08; p = 0.04).Conclusions: We conclude that cervical block anesthesia is safer and results in a more efficient use of hospital resources than general anesthesia in the treatment of patients undergoing carotid endarterectomy. (J VASC SURG 1994;19:834-43.)     

Propofol EEG burst suppression in carotid endarterectomy.

BACKGROUND: The results of randomized trials indicate that carotid endarterectomy, performed with a low morbidity-mortality perioperative risk, is the best therapeutic option both for patients with high-grade symptomatic and asymptomatic stenosis. Since the main operative risk is represented by embolic or hemodynamic cerebral ischemia, it appears necessary to maintain an adequate intraoperative cerebral blood flow and to carry out a meticulous endarterectomy. METHODS: On the basis of these considerations we prospectively studied a series of 100 consecutive patients operated on for high-grade carotid stenosis, by using a protocol based on: 1) an accurate selection of patients for surgery; 2) meticulous surgical technique without any shunt; 3) perioperative cerebral protection by barbiturate or propofol; 4) pre- and postoperative medical treatment of risk factors. All patients of our series performed preoperatively brain CT scan, transcranial Doppler, carotid duplex scanning, four vessel angiography, brain 99mTc-HMPAO SPECT. Eighty-two patients had symptomatic carotid stenosis ranged between 70 and 90%, 18 had carotid stenosis higher than 90%. RESULTS: In this series there have been one postoperative death due to myocardial infarction and one major stroke. CONCLUSIONS: We think that this protocol can significantly minimize risks of endarterectomy and probably maximize the benefits of surgery, also in patients with asymptomatic high-grade carotid stenosis.     

Cerebral oximetry in patients undergoing carotid endarterectomy: preliminary results

Carotid endarterectomy (CEA) is an appropriate treatment for carotid occlusive disease. The risk of stroke during CEA ranges from 1.1% to 7.5%. Shunting is usually advised when severe ischemia during cross-clamping of the internal carotid artery is suspected. Routine use of an intraluminal shunt may increase the perioperative stroke rate. Popular and well documented methods of neurologic monitoring for ischemia during general anesthesia are electroencephalography (EEG) and transcranial Doppler ultrasonography (TCD) of the middle cerebral artery. The purpose of this prospective study was to compare cerebral oximetry using near infrared spectrophotometry (NIRS) with EEG and TCD. Preliminary data on 14 patients scheduled for elective carotid endarterectomy were included and a literature search was performed to correlate the findings. No postoperative neurologic events occurred. During carotid clamping there was a significant decrease in regional oxygen saturation (rSO2) but there was only a weak correlation with the decrease in mean Doppler flow (R = 0.74; P = 0.02) and no correlation with EEG changes (R = 0.49; P = 0.18). A useful rSO2 cut-off value predictive for cerebral ischemia could not be defined.     

Use of shunts with eversion carotid endarterectomy

PURPOSE: The purpose of this study was to examine the utility of carotid shunting in the context of eversion endarterectomy. A comparison of patients who underwent carotid endarterectomy by eversion with and without shunts was performed. METHODS: Over a 5-year period, 2724 eversion carotid endarterectomies were performed. In most of these operations patients were under cervical block anesthesia. A shunt was used in 112 eversion endarterectomies (4.1%). Cervical block anesthesia was used in 103 patients (92.0%), general anesthesia was used in 5 patients (4.5%), and 4 patients (3.6%) were converted from cervical block to general anesthesia intraoperatively. The indications for shunting were neurologic deterioration in 99 patients (88.4%) who were under cervical block anesthesia, procedures performed in neurologically unstable or otherwise compromised patients who were under general anesthesia, and the operator's discretion in the remaining eight patients. RESULTS: There was a combined stroke/death rate of 2.7% in the shunt group. These three cases included one death from myocardial infarction and one delayed death due to intracerebral hemorrhage after discharge. Shunt insertion was unrelated to the negative outcome in these two cases. One perioperative major stroke in the shunt group was identified. Follow-up averaged 12.3 months (range, 1-53 months). CONCLUSION: Carotid shunts can be used effectively in the context of eversion endarterectomy. Shunt insertion is not associated with an increased stroke/death rate in these patients.     

Carotid endarterectomy after recent stroke: preliminary observations in patients undergoing early operation

Three patients with recent stroke underwent carotid endarterectomy 1, 4, and 8 days after the onset of maximal symptoms. In each case, computed tomography (CT) demonstrated recent cerebral infarction and cerebral arteriography showed high grade cervical carotid stenosis. No patient developed worsened neurological symptomatology, intracerebral hemorrhage, or vasomotor paralysis. These results suggest that carotid endarterectomy, if indicated, can be performed safely after acute stroke under certain conditions. These criteria include the following: normal level of consciousness, relatively small cerebral infarction without mass effect on CT, and meticulous control and monitoring of systemic blood pressure during the perioperative period. These initial observations suggest that a specific subgroup of patients with recent cerebral infarction may be able safely to undergo carotid endarterectomy shortly after diagnosis.     

Risk of Early Controlateral Carotid Endarterectomy

Between January 1984 and January 1994, we performed early endarterectomy of the controlateral carotid on 94 patients within a delay of 1 to 8 days after the first endarterectomy. Lesions were symptomatic in 58 patients (62%) and asymptomatic in 36 patients (38%). Eighty-four operations were performed under cervical block anesthesia (89%), eight under general anesthesia, and two under local anesthesia (2%). Severe intraoperative hypertension occurred in seven patients (7%) including five under cervical block anesthesia (6%) and two under general anesthesia (25%). Two patients (2.1%) died of stroke secondary to carotid thrombosis in one case and hyperperfusion syndrome in one case. Morbidity included one transient ischemic attack (1%) and one myocardial infarction (1%). Postoperative control of patency revealed asymptomatic occlusion of the internal carotid artery in two patients, accounting for one of the two deaths. Our findings demonstrate that neurologic mortality/morbidity is not higher after early controlateral carotid endarterectomy than unilateral endarterectomy. (Ann Vasc Surg 1997;11: 491–495.)     

Regional or general anesthesia for carotid endarterectomy? Evidence from published prospective and retrospective studies

OBJECTIVES: The aim of this study was to compare outcomes of patients undergoing carotid endarterectomy under regional or general anesthesia for any new neurologic impairment, stroke, stroke and/or death, death, and myocardial infarction. DESIGN: Meta-analysis. SETTING: A search of the National Library of Medicine of the United States PUBMED from 1966 up to June 11, 2005, with the following key words: "carotid surgery or endarterectomy and regional anesthesia." MEASUREMENTS AND MAIN RESULTS: Forty-eight studies (14 prospective and 34 retrospective) were analyzed. The optimal information size was achieved only when all studies were analyzed together (prospective and retrospective). Regional anesthesia reduced the rate of any new neurologic impairment (odds ratio = 0.60; 95% confidence interval, 0.48-0.75; p < 0.00001), stroke (0.54 [0.43-0.68], p < 0.00001), stroke and/or death (0.62 [0.49-0.78], p < 0.0001), death (0.65 [0.48-0.87], p = 0.004), and myocardial infarction (0.50 [0.36-0.70], p < 0.0001). CONCLUSION: The number of patients included in randomized controlled trials or even in prospective studies is too low to allow any conclusions on the differences in outcome between the 2 anesthetic techniques. Better outcomes are suggested when results from retrospective studies are added.     

Determinants of carotid microembolization

PURPOSE: Earlier studies have highlighted risk factors for perioperative stroke after carotid endarterectomy, such as female sex, preoperative symptoms, and cerebral infarction. In this study, we investigated the relationship between these factors and perioperative microembolization. METHODS: A total of 235 patients were entered in the study at two centers. Transcranial Doppler ultrasound scanning was possible in 190 patients (81%) and was performed for 1 hour preoperatively and continuously intraoperatively as a means of detecting microemboli and monitoring mean middle cerebral artery velocity. The findings of transcranial Doppler ultrasound scanning were related to perioperative risk factors by means of univariate analysis. RESULTS: Microemboli were detected in 28 (15%), 79 (42%), and 98 (52%) patients preoperatively, during carotid artery dissection, and after closure of the artery, respectively. Having 10 or more emboli after carotid artery closure was more common in women (P = .04) and in patients with symptomatic carotid artery disease (P = .04) and was demonstrated in three of the six patients who had a perioperative stroke. These three patients also had preoperative evidence of cerebral infarction and an intraoperative middle cerebral artery velocity less than 40 cm/s. CONCLUSION: In this study, perioperative microembolization was more common in women and patients with symptomatic carotid artery disease. These findings may explain the increased risk of carotid surgery in these patients.     

Microsurgical endarterectomy under barbiturate protection: a prospective study

Carotid endarterectomy has the potential to improve on the natural history of untreated carotid artery disease with respect to subsequent infarction in symptomatic patients with causative angiographic lesions. This benefit of a reduced risk of stroke can be realized only if the perioperative morbidity and mortality rates are kept low. An approach to symptomatic carotid artery bifurcation disease is outlined, with a defined protocol of microsurgical endarterectomy utilizing barbiturate protection during the period of potential focal temporary cerebral ischemia. This protocol includes preoperative antiplatelet therapy, barbiturate anesthesia, the avoidance of an internal shunt, the use of the operating microscope, and strict control of postoperative hypertension. A series of 200 consecutive endarterectomies performed within this protocol in 180 patients and the resultant combined permanent morbidity and mortality rate of 1.5% are reported.     

General anesthesia versus regional anesthesia

No distinct advantage is apparent between regional and general anesthesia when considering perioperative cardiac morbidity and mortality in peripheral vascular surgery. However, there is some evidence to support regional anesthesia over general anesthesia in an effort to optimize graft patency if the regional technique is extended into the postoperative period to provide neuraxial analgesia. An inadequate number of randomized, controlled trials have been conducted to determine whether regional or general anesthesia should be performed for carotid endarterectomy. The nonrandomized trials do support regional anesthesia by virtue of reductions in stroke, myocardial infarction, and death. A randomized, prospective trial is needed to verify these outcomes. The choice of technique does not appear to affect mortality in patients requiring hip fracture surgery, although Urwin et al. (29) reported less 1-month mortality in patients receiving regional anesthesia. General anesthesia has been associated with increased blood loss and thromboembolic complications in patients undergoing hip fracture repair. Epidural anesthesia has been shown to promote quicker return of bowel function postoperatively when the catheter has been sited at T12 or higher. Anastomotic breakdown in patients with epidural anesthesia/analgesia has rarely been reported. Most studies tend to show quicker return of bowel function when local anesthetics alone are administered epidurally.     

颈动脉外翻内膜剥脱术治疗颈动脉硬化狭窄

目的观察颈动脉外翻内膜剥脱术治疗颈动脉狭窄的疗效。方法24例颈动脉硬化狭窄患者,其中18例有慢性或一过性脑缺血症状,6例无症状;术前均行彩色超声、数字减影动脉造影(DSA)或CT和MRA扫描检查,颈动脉狭窄程度65％～95％;在颈丛麻醉下行颈动脉外翻内膜剥脱术,手术要点是于颈动脉分叉处斜形切断颈内动脉,外翻颈内动脉剥除有粥样斑块的内膜,同时从颈总动脉切口剥除颈总动脉和颈外动脉增厚的内膜。结果全组无手术死亡,术后随访3～20个月,临床症状均有不同程度改善,一过性脑缺血症状消失,4例仍有轻度慢性脑缺血症状。术后行脑部多普勒超声检查,22例脑部供血有明显改善。结论颈动脉外翻内膜剥脱术是一种安全、有效和合理的手术方式。     

Stroke prevention during carotid surgery in high risk patients (value of transcranial Doppler and local anesthesia).

In a series of 114 cases, carotid surgery was performed under local anesthesia by cervical block in order to assess cerebral status. Preoperative transcranial Doppler was used to select high risk patients for shunting. Intraoperatively brain function was checked by carotid arterial blood pressure monitoring and transcranial Doppler. No stroke occurred during the procedure. Postoperatively two deaths (1.8%) occurred, one due to intracerebral hemorrhage and one to a late myocardial infarct. The predictive value of both transcranial Doppler and stump pressure monitoring for shunting was 97% respectively. In combination, the two methods provided 100% protection. During the same period, 1406 patients underwent carotid surgery under general anesthesia. Carotid surgery stroke can be prevented either by using transcranial Doppler together with carotid stump pressure monitoring when the procedure is performed under general anesthesia or by operating under local anesthesia.