Physiological advantages of cerebral blood flow during carotid endarterectomy under local anaesthesia. A randomised clinical trial

Optimal cutoff value of carotid stump pressure for determining the need for a carotid shunt in carotid artery endarterectomy

OBJECTIVE

This study was conducted to identify the diagnostic value of carotid stump pressure for determining the need for a carotid artery shunt in patients undergoing carotid artery endarterectomy.

MATERIALS AND METHODS

Carotid stump pressure was prospectively measured in all carotid artery endarterectomies performed under local anesthesia between January 2020 and April 2022. The shunt was selectively used when neurological symptoms appeared after carotid cross-clamping. Carotid stump pressure was compared between patients who needed shunting and those who did not. Demographic and clinical characteristics, hematological and biochemical parameters, and carotid stump pressure of the patients with and without shunts were statistically compared. To determine the optimal cutoff value and diagnostic performance of carotid stump pressure for identifying the patients who need a shunt, receiver operating characteristic analysis was performed.

RESULTS

Overall, 102 patients (61 men and 41 women) who underwent carotid artery endarterectomy under local anesthesia were included, with an age range of 51-88 years. A carotid artery shunt was used in 16 (8 men and 8 women) patients. The carotid stump pressure values of the patients with a shunt were lower than those without a shunt (median (min-max): 42 (20-55) vs 51 (20-104), p < 0.0006). In the receiver operating characteristic curve analysis performed to determine the need for a shunt, the optimal cutoff value of carotid stump pressure was ≤48 mmHg, sensitivity was 93.8%, and specificity was 61.6% (area under the curve: 0.773, p < 0.0001).

CONCLUSION

Carotid stump pressure has sufficient diagnostic power to determine the need for a shunt, but it cannot be used alone in the clinical setting. Instead, it can be used in combination with other neurological monitoring methods.

The value of transcranial Doppler monitoring of cerebral blood flow changes during carotid endarterectomy performed under regional anesthesia - A case series

Recent evidence suggests no difference between patient outcomes when carotid endarterectomies (CEAs) are performed under general or regional anesthesia. However, for detecting the need for a shunt, general anesthesia has the drawback of monitoring needs in the intraoperative setting. In the present study, we attempted to perform intraoperative transcranial Doppler (TCD) monitoring for CEAs performed under intermediate plexus block to describe cerebral hemodynamic changes during different phases of the procedure.

Patients and methods

Patients with unilateral hemodynamically significant carotid stenosis scheduled for elective CEAs were included. Ultrasound-guided intermediate plexus block was used for regional anesthesia. TCD monitoring of the middle cerebral artery mean blood flow velocity (MCAV) was performed throughout the procedure. MCAVs were offline analyzed during different phases of CEA: (1) resting state, before regional block, (2) after block, before incision, (3) before cross-clamp, (4) after cross-clamp, (5) 5 min after cross-clamp, (6) 10 min after cross-clamp, (7) after declamping, and (8) during the postoperative period (4-6 h).

Results

Shunt insertion based on the deterioration of neurological symptoms after cross-clamping was necessary for 11/66 patients (16.6%). In these symptomatic patients, the ipsilateral percent decrease of the MCAV was more than 70% in 8 out of 11 cases (72.7%). In asymptomatic patients, without shunt insertion, the average decrease of MCAV was less than 50%.

Conclusions

Neurological symptoms referring to cerebral ischemia may be superior to TCD monitoring of cerebral blood flow for detecting the necessity of a shunt. Regional anesthesia enables reliable, symptom-based monitoring of CEAs.

A systematic review & meta-analysis on perioperative cerebral and hemodynamic monitoring methods during carotid endarterectomy

OBJECTIVE

To compare outcomes between different strategies of perioperative cerebral and hemodynamic monitoring during carotid endarterectomy.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL databases were searched.

METHODS

This review was performed according to the PRISMA guidelines and prospectively registered in the international prospective register of systematic reviews (CRD42021241891). The GRADE approach was used to describe the methodological quality of the studies and certainty of the evidence. The primary outcome was 30-day stroke rate. Secondary outcomes measures are 30-day ipsilateral stroke, 30-day mortality, shunt rate and complication rates.

RESULTS

The search identified 3 460 articles. Seventeen RCTs, three prospective observational studies and seven registries were included, reporting on 236 983 patients. The overall pooled 30-day stroke rate is 1.8% (95% CI 1.4 - 2.2%), ranging from 0 - 12.6%. In RCT's the pooled 30-day stroke rate is 2.7% (95% CI 1.6 - 3.7%) compared to 1.3% (95%CI 0.8 - 1.8%) in the registries. The overall stroke risk decreased from 3.7% before the year 2000 to 1.6% after 2000. No significant differences could be identified between different monitoring and shunting strategies, although a trend to higher stroke rates in routine no shunting arms of RCTs was observed. Overall 30-day mortality, myocardial infarction and nerve injury rates are 0.6% (95%CI 0.4 - 0.8), 0.8% (95%CI 0.6-1.0) and 1.3% (95%CI 0.4-2.2), respectively.

CONCLUSIONS

No significant differences between the compared shunting and monitoring strategies are found. However, routine no shunting is not recommended. The available data is too limited to prefer one method of neuromonitoring over another method when selective shunting is applied.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy may significantly reduce the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks that may be minimised by performing the operation under local rather than general anaesthetics. This is an update of a Cochrane Review first published in 1996, and previously updated in 2004, 2008, and 2013.

OBJECTIVES

To determine whether carotid endarterectomy under local anaesthetic: 1) reduces the risk of perioperative stroke and death compared with general anaesthetic; 2) reduces the complication rate (other than stroke) following carotid endarterectomy; and 3) is acceptable to individuals and surgeons.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trials registers (to February 2021). We also reviewed reference lists of articles identified.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the use of local anaesthetics to general anaesthetics for people having carotid endarterectomy were eligible.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, assessed risk of bias, and evaluated quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool. We calculated a pooled Peto odds ratio (OR) and corresponding 95% confidence interval (CI) for the following outcomes that occurred within 30 days of surgery: stroke, death, ipsilateral stroke, stroke or death, myocardial infarction, local haemorrhage, and arteries shunted.

MAIN RESULTS

We included 16 RCTs involving 4839 participants, of which 3526 were obtained from the single largest trial (GALA). The main findings from our meta-analysis showed that, within 30 days of operation, neither incidence of stroke nor death were significantly different between local and general anaesthesia. Of these, the incidence of stroke in the local and general anaesthesia groups was 3.2% and 3.5%, respectively (Peto odds ratio (OR) 0.91, 95% confidence interval (CI) 0.66 to 1.26; P = 0.58; 13 studies, 4663 participants; low-quality evidence). The rate of ipsilateral stroke under both types of anaesthesia was 3.1% (Peto OR 1.03, 95% CI 0.71 to 1.48; P = 0.89; 2 studies, 3733 participants; low-quality evidence). The incidence of stroke or death in the local anaesthesia group was 3.5%, while stroke or death incidence was 4.1% in the general anaesthesia group (Peto OR 0.85, 95% CI 0.62 to 1.16; P = 0.31; 11 studies, 4391 participants; low-quality evidence). A lower rate of death was observed in the local anaesthetic group but evidence was of low quality (Peto OR 0.61, 95% CI 0.35 to 1.06; P = 0.08; 12 studies, 4421 participants).

AUTHORS' CONCLUSIONS

The incidence of stroke and death were not convincingly different between local and general anaesthesia for people undergoing carotid endarterectomy. The current evidence supports the choice of either approach. Further high-quality studies are still needed as the evidence is of limited reliability.

General Anesthesia Versus Local Anesthesia in Carotid Endarterectomy: A Systematic Review and Meta-Analysis

OBJECTIVE

The choice of anesthetic technique in carotid endarterectomy (CEA) has been controversial. This study compared the outcomes of general anesthesia (GA) and local anesthesia (LA) in CEA.

DESIGN

Systematic review and meta-analysis of comparative studies.

SETTING

Hospitals.

PARTICIPANTS

Adult patients undergoing CEA with either LA or GA.

INTERVENTIONS

The effects of GA and LA on CEA outcomes were compared.

MEASUREMENTS AND MAIN RESULTS

PubMed, OVID, Scopus, and Embase were searched to June 2018. Thirty-one studies with 152,376 patients were analyzed. A random effect model was used, and heterogeneity was assessed with the I² and chi-square tests. LA was associated with shorter surgical time (weighted mean difference -9.15 min [-15.55 to -2.75]; p = 0.005) and less stroke (odds ratio [OR] 0.76 [0.62-0.92]; p = 0.006), cardiac complications (OR 0.59 [0.47-0.73]; p < 0.00001), and in-hospital mortality (OR 0.72 [0.59-0.90]; p = 0.003). Transient neurologic deficit rates were similar (OR 0.69 [0.46-1.04]; p = 0.07). Heterogeneity was significant for surgical time (I² = 0.99, chi-square = 1,336.04; p < 0.00001), transient neurologic deficit (I² = 0.41, chi-square = 28.81; p = 0.04), and cardiac complications (I² = 0.42, chi-square = 43.32; p = 0.01) but not for stroke (I² = 0.22, chi-square = 30.72; p = 0.16) and mortality (I² = 0.00, chi-square = 21.69; p = 0.65). Randomized controlled trial subgroup analysis was performed, and all the aforementioned variables were not significantly different or heterogenous.

CONCLUSION

The results from this study showed no inferiority of using LA to GA in patients undergoing CEA. Future investigations should be reported more systematically, preferably with randomization or propensity-matched analysis, and thus registries will facilitate investigation of this subject. Anesthetic choice in CEA should be individualized and encouraged where applicable.

Temporal Trends in Eversion Carotid Endarterectomy for Carotid Atherosclerosis: Single-Center Experience with 5,034 Patients

The aim of this article is to review our experience in surgical treatment of carotid atherosclerosis using eversion carotid endarterectomy (ECEA) in 5,034 patients, with particular attention to temporal changes in patients' characteristics, diagnostic approach, surgical technique, medical therapy, and outcome in the early (group A, 1991–1997) versus late (group B 1998–2004) period of ECEA. From January 1991 to December 2004, 5,034 primary ECEAs were performed for high-grade carotid stenosis. Patients treated for restenosis after previous carotid surgery were excluded from the analysis. Group A consisted of 1,714 patients who underwent surgery between 1991 and 1997, and group B consisted of 3,320 patients who underwent surgery between 1998 and 2004. Follow-up included routine clinical evaluation and noninvasive surveillance, with duplex scanning at 1 month after surgery, after 6 months, and annually afterward. Only 3% of patients in group A and 0.6% in group B were asymptomatic, with 23% and 47% of them having preoperative stroke, respectively. In group A, angiography was used for the final diagnosis in 78% of patients. In group B, duplex scanning was performed in 82% of patients and angiography in only 18% ( p < .001). Clamping time was shorter in the latter group (12.4 ± 3.1 vs 14.5 ± 4.1 min, p < .01). Introperative shunting and regional anesthesia were rarely performed in both groups (1.4% vs. 0.4%, p < .01, and 2% vs 0.3%, p < .001). Total and neurologic morbidity was significantly higher in group A than in group B (6.41% ± 0.47% vs 4.81% ± 0.53%, p < .001, and 2.14% ± 0.31% vs 1.23% ± 0.29%, p < .001, respectively). Total mortality was also higher in group A than in group B (1.92% ± 0.24% vs 1.36% ± 0.50%, p < .05), but although there was a trend toward lower neurologic mortality, it did not reach statistical significance (1.04% ± 0.5% vs 0.57% ± 0.25%, p = .074). There was a lower rate of nonsignificant restenosis (< 50%) in group B (2% vs 5%, p < .01), but the incidence of restenosis ≥ 50% was identical between the groups (5.5% for both). Our data show that ECEA is a reliable surgical technique for the treatment of atherosclerotic carotid disease. Temporal trends in our patients demonstrated a decline in periopertive mortality and morbidity, despite a higher incidence of preoperative stroke.

Combined Carotid Endarterectomy and Retrograde Stenting of the Supra-Aortic Trunk: Does Cervical Block Offer Advantages?

BACKGROUND

Atherosclerosis of the carotid artery is a major source of stroke. In some cases, atherosclerosis occurs at several positions within the carotid artery. Carotid endarterectomy (CEA) in combination with retrograde balloon angioplasty and stenting of a brachiocephalic or common carotid artery stenosis has been described as efficacious and safe procedure to prevent stroke in these cases. The aim of this study was to analyze the impact of anesthetic techniques on hemodynamic factors, operation time, duration of clamping, and postoperative pain.

METHODS

A retrospective analysis of patients undergoing CEA in combination with retrograde stenting under either general anesthesia (GA) or cervical block (CB) was carried out. Preoperative risk factors were analyzed as well as operating and cross-clamping time, hemodynamic factors, perioperative complications, postoperative pain, application of pain killers, and duration of intensive care unit (ICU) and hospital stay.

RESULTS

Operating (GA: 193 ± 91 min vs. CB: 125 ± 52 min, P = 0.029) and cross-clamping time (GA: 34 ± 12 min vs. CB: 26 ± 9 min, P < 0.001) were shorter under CB. Patients under CB were hemodynamically more stable and required less norepinephrine (GA: 1.1 ± 0.6 mg vs. CB: 0.1 ± 0.1 mg, P < 0.001) and crystalloids (GA: 2,813 ± 1,173 mL vs. CB: 1,088 ± 472 mL, P < 0.001). Postoperative pain levels (GA: numeric rating scale 4.3/10 vs. 2.0/10; P = 0.004) and requirement of pain killers were also lower within the CB group.

CONCLUSIONS

Synchronous CEA and retrograde balloon angioplasty and stenting of a brachiocephalic or common carotid artery stenosis under CB is associated with reduction of operating and cross-clamping time, improved hemodynamical stability, lower postoperative pain, shorter ICU and hospital stay, and it offers the advantage of a continuous neurological monitoring.

Effect of Superficial Cervical Plexus Block on Baroreceptor Sensitivity in Patients Undergoing Carotid Endarterectomy

OBJECTIVES

Regional anesthesia for patients undergoing carotid endarterectomy is associated with improved intraoperative hemodynamic stability compared with general anesthesia. The authors hypothesized that the reported advantages might be related to attenuated ipsilateral baroreflex control of blood pressure, caused by chemical denervation of the carotid bulb baroreceptor nerve fibers.

DESIGN

A prospective cohort study.

SETTING

Single-center university hospital.

PARTICIPANTS

The study included 46 patients undergoing carotid endarterectomy using superficial cervical block.

INTERVENTIONS

A noninvasive computational periprocedural measurement of baroreceptor sensitivity was performed in all patients. Two groups were formed, depending on the patients' subjective response to surgical stimulation regarding the necessity of additional intraoperative local anesthesia (LA) administration on the carotid bulb. Group A (block alone) included 23 patients who required no additional anesthesia, and group B (block + LA) consisted of 23 patients who required additional anesthesia.

MEASUREMENTS AND MAIN RESULTS

Baroreceptor sensitivity showed no significant change after application of the block in both groups (group A: median [IQR], 5.19 [3.07-8.54] v 4.96 [3.1-9.07]; p = 0.20) (group B: median [IQR], 4.47 [3.36-8.09] v 4.53 [3.29-8.01]; p = 0.55). There was a significant decrease in baroreceptor sensitivity in group B after intraoperative LA administration (median [IQR], 4.53 [3.29-8.01] v 3.31 [2.26-7.31]; p = 0.04).

CONCLUSIONS

Standard superficial cervical plexus block did not impair local baroreceptor function, and, therefore, it was not related to improved cerebral perfusion in awake patients undergoing carotid endarterectomy. However, direct infiltration of the carotid bulb was associated with the expected attenuation of baroreflex sensitivity.

Carotid endarterectomy: review of 10 years of practice of general and locoregional anesthesia in a tertiary care hospital in Portugal

BACKGROUND

Retrospective and prospective randomized studies have compared general and locoregional anesthesia for carotid endarterectomy, but without definitive results.

OBJECTIVES

Evaluate the incidence of complications (medical, surgical, neurological, and hospital mortality) in a tertiary center in Portugal and review the literature.

METHODS

Retrospective analysis of patients undergoing endarterectomy between 2000 and 2011, using a software for hospital consultation.

RESULTS

A total of 750 patients were identified, and locoregional anesthesia had to be converted to general anesthesia in 13 patients. Thus, a total of 737 patients were included in this analysis: 74% underwent locoregional anesthesia and 26% underwent general anesthesia. There was no statistically significant difference between the two groups regarding per operative variables. The use of shunt was more common in patients undergoing general anesthesia, a statistically significant difference. The difference between groups of strokes and mortality was not statistically significant. The average length of stay was shorter in patients undergoing locoregional anesthesia with a statistically significant difference.

CONCLUSIONS

We found that our data are overlaid with the literature data. After reviewing the literature, we found that the number of studies comparing locoregional and general anesthesia and its impact on delirium, cognitive impairment, and decreased quality of life after surgery is still very small and can provide important data to compare the two techniques. Thus, some questions remain open, which indicates the need for randomized studies with larger number of patients and in new centers.

Perioperative results eversion carotid endarterectomy in bilateral symptomatic stenosis

Introduction:

Carotid endarterectomy (CEA) is a standard treatment for the prevention of stroke and death in patients with significant stenosis of the internal carotid artery. Eversion endarterectomy is warranted in patients with symptoms of cerebral ischemia and the degree of stenosis of 70-99%. The same is suitable for treating a symptomatic carotid artery stenosis with contralateral stenosis (50-70%).

Purpose:

The aim of this study was to evaluate perioperative complications (ICV, TIA, MI, mortality) in patients treated with carotid eversion endarterectomy with unilateral and bilateral symptomatic stenosis (with bilateral stenosis treated with ACI stenosis ≥70%).

Patients and Methods:

The study included 139 patients with symptomatic carotid artery stenosis at the Department of Vascular Surgery of the University Clinical Center of Sarajevo in the period from January 2012 to December 2014 year. Given the involvement of ACI stenosis patients were divided into two groups. Group A consisted of 74 patients with bilateral stenosis (surgically treated with ACI stenosis ≥70%, while the degree of stenosis opposite ACI was from 50-70%), and group B of 65 patients with unilateral stenosis ≥70%.

Results:

Of the 139 patients included in the study, in the group A was 74, of which 46 male (62.2%) and 28 female (37.8%), while in group B were 42 male (64.6%) and 23 female (35.4%) (p = 0.90). The subjects in group A were slightly older 65.9 (± 7.8) compared to group B 64.2 (± 7.7) (p = 0.17). Analysis of risk factors indicating a higher number in Group A compared to group B, but the difference was not statistically significant: 34 smokers (45.9%) versus 36 (55.4%); p = 0:34), patients with hypertension (63 (85.1%) against the 52 (80.0%); p = 0.56), with statin therapy (62 (83.8%) versus 52 (80.0%); p = 0.72), diabetes (18 (24.3%) versus 18 (27.7%); p = 0.79) and with a heart disease (18 (24.3%) versus 7 (10.8%); p = 0.06). Analysis of the frequency of perioperative complications between the groups was not statistically significant: ICV (2/74 versus 3/65; p = 1.00), TIA (2/74 versus 3/65; p = 0.88), one death was recorded in group A, while myocardial infarction (MI) we had in either group.

Conclusion:

In this study, no statistically about significant differences in the number of perioperative complications (from 0 to 30 days) between the two groups. With this risk is acceptable to perform carotid endarterectomy in a patient in the opposite ACI stenosis of 50-70%.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy may significantly reduce the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks that may be reduced by performing the operation under local rather than general anaesthetic. This is an update of a Cochrane Review first published in 1996, and previously updated in 2004 and 2008.

OBJECTIVES

To determine whether carotid endarterectomy under local anaesthetic: (1) reduces the risk of perioperative stroke and death compared with general anaesthetic; (2) reduces the complication rate (other than stroke) following carotid endarterectomy; and (3) is acceptable to patients and surgeons.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (September 2013), MEDLINE (1966 to September 2013), EMBASE (1980 to September 2013) and Index to Scientific and Technical Proceedings (ISTP) (1980 to September 2013). We also handsearched relevant journals, and searched the reference lists of articles identified.

SELECTION CRITERIA

Randomised trials comparing the use of local anaesthetic to general anaesthetic for carotid endarterectomy were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial quality and extracted data. We calculated a pooled Peto odds ratio (OR) and corresponding 95% confidence interval (CI) for the following outcomes that occurred within 30 days of surgery: stroke, death, stroke or death, myocardial infarction, local haemorrhage, cranial nerve injuries, and shunted arteries.

MAIN RESULTS

We included 14 randomised trials involving 4596 operations, of which 3526 were from the single largest trial (GALA). In general, reporting of methodology in the included studies was poor. All studies were unable to blind patients and surgical teams to randomised treatment allocation and for most studies the blinding of outcome assessors was unclear. There was no statistically significant difference in the incidence of stroke within 30 days of surgery between the local anaesthesia group and the general anaesthesia group. The incidence of strokes in the local anaesthesia group was 3.2% compared to 3.5% in the general anaesthesia group (Peto OR 0.92, 95% CI 0.67 to 1.28). There was no statistically significant difference in the proportion of patients who had a stroke or died within 30 days of surgery. In the local anaesthesia group 3.6% of patients had a stroke or died compared to 4.2% of patients in the general anaesthesia group (Peto OR 0.85, 95% CI 0.63 to 1.16). There was a non-significant trend towards lower operative mortality with local anaesthetic. In the local anaesthesia group 0.9% of patients died within 30 days of surgery compared to 1.5% of patients in the general anaesthesia group (Peto OR 0.62, 95% CI 0.36 to 1.07). However, neither the GALA trial or the pooled analysis were adequately powered to reliably detect an effect on mortality.

AUTHORS' CONCLUSIONS

The proportion of patients who had a stroke or died within 30 days of surgery did not differ significantly between the two types of anaesthetic techniques used during carotid endarterectomy. This systematic review provides evidence to suggest that patients and surgeons can choose either anaesthetic technique, depending on the clinical situation and their own preferences.

Eversion carotid endarterectomy--our experience after 20 years of carotid surgery and 9897 carotid endarterectomy procedures

BACKGROUND

The aim of this article is to review our experience in surgical treatment of carotid atherosclerosis using eversion carotid endarterectomy (eCEA) in 9,897 patients performed in the last 20 years, with particular attention to diagnostic approach, surgical technique, medical therapy, and final outcome.

METHODS

From January 1991 to December 2010, 9,897 primary eCEAs were performed for high-grade carotid stenosis. Patients treated for restenosis after previous carotid surgery were excluded from the analysis. Follow-up included routine clinical evaluation and noninvasive surveillance, with duplex scanning, 1 and 6 months after surgery, and annually afterward.

RESULTS

The majority of the patients were symptomatic (stroke, 42.8%; transient ischemic attack, 55.1% [focal cerebral and retinal ischemia]), whereas only 2.1% of the patients were asymptomatic. For the final diagnosis, duplex scanning was performed in 83.4% of patients and angiography in only 16.3% (P < 0.001). Average carotid artery clamping time was 11.9 ± 3.2 minutes, and the majority of the patients were operated under general anesthesia (99.4%). Intraoperative shunting and local anesthesia were rarely performed; 0.6% of the patients were operated under local anesthesia, and in 0.5% of the patients, intraluminal shunt was used. Neurological and total morbidity showed a steady decline over time, with rate of neurological morbidity of 1.1% and total morbidity of 3.9% at the end of 2010. Neurological mortality and total mortality also showed a steady decline over time, with rate of neurological mortality of 0.3% and total mortality of 0.8% at the end of 2010. There was a low rate of both, nonsignificant restenosis (<50%), which was verified in 2.1% of the patients, and significant restenosis (>50%), which was observed in 4.3% of the patients.

CONCLUSION

Our data show that eCEA is a reliable surgical technique for the treatment of atherosclerotic carotid disease, with low morbidity and mortality. The specificity of our experience is the significant number of patients with preoperative stroke, but despite this fact, results are comparable with previously published series. It also highlights the importance of comprehensive surgical training in reducing complications.

Outcomes of carotid endarterectomy under general and regional anesthesia from the American College of Surgeons' National Surgical Quality Improvement Program

OBJECTIVE

Despite multiple studies over more than 3 decades, there still is no consensus about the influence of anesthesia type on postoperative outcomes following carotid endarterectomy (CEA). The objective of this study was to investigate whether anesthesia type, either general anesthesia (GA) or regional anesthesia (RA), independently contributes to the risk of postoperative cardiovascular complications or death using the American College of Surgeons' National Surgical Quality Improvement Program (ACS NSQIP) database.

METHODS

Retrospective analysis of elective cases of CEA from 2005 through 2009 was performed. A propensity score model using 45 covariates, including demographic factors, comorbidities, stroke history, measures of general health, and laboratory values, was used to adjust for bias and to determine the independent influence of anesthesia type on postoperative stroke, myocardial infarction (MI), and death.

RESULTS

Of 26,070 cases listed in the ACS NSQIP database, GA and RA were used in 22,054 (84.6%) and 4016 (15.4%) cases, respectively. Postoperative stroke, MI, and death occurred in 360 (1.63%), 133 (0.6%), and 154 (0.70%) patients of the GA group, respectively, and in 58 (1.44%), 11 (0.27%), and 27 (0.67%) patients of the RA group, respectively. Stratification by propensity score quintile and adjustment for covariates demonstrated GA to be a significant risk factor for postoperative MI with an adjusted odds ratio (OR) and confidence interval (CI) of 2.18 (95% CI, 1.17-4.04), P = .01 in the entire study population. The OR for MI was 5.41 (95% CI, 1.32-22.16; P = .019) in the subgroup of patients with preoperative neurologic symptoms, and 1.44 (95% CI, 0.71-2.90; P = .31) in the subgroup of patients without preoperative neurologic symptoms.

CONCLUSIONS

This analysis of a large, prospectively collected and validated multicenter database indicates that GA for CEA is an independent risk factor for postoperative MI, particularly in patients with preoperative neurologic symptoms.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy reduces the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks which may be lessened by performing the operation under local rather than general anaesthetic. This is an update of a Cochrane review first published in 1996, and previously updated in 2004.

OBJECTIVES

To assess the risks of endarterectomy under local compared with general anaesthetic.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched December 2007), MEDLINE (1966 to April 2007) EMBASE (1980 to April 2007) and Index to Scientific and Technical Proceedings (ISTP, 1980 to April 2007). We also handsearched six relevant journals to April 2007, and searched the reference lists of articles identified. For the previous version of this review we handsearched a further seven journals to 2002 and in August 2001 advertised the review in Vascular News, a newspaper for European vascular specialists.

SELECTION CRITERIA

Randomised trials and non-randomised studies comparing carotid endarterectomy under local versus general anaesthetic.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality and extracted the data independently.

MAIN RESULTS

Nine randomised trials involving 812 operations, and 47 non-randomised studies involving 24,181 operations were included. Meta-analysis of the randomised studies showed that there was no evidence of a reduction in the odds of operative stroke, but the use of local anaesthetic was associated with a significant reduction in local haemorrhage (odds ratio 0.30, 95% confidence interval 0.12 to 0.77) within 30 days of the operation. However, the randomised trials were too small to allow reliable conclusions to be drawn, and in some studies intention-to-treat analyses were not possible because of exclusions. Meta-analsis of the non-randomised studies showed that the use of local anaesthetic was associated with significant reductions in the odds of stroke (38 studies), death (42 studies), stroke or death (27 studies), myocardial infarction (27 studies), and pulmonary complications (seven studies), within 30 days of the operation. The methodological quality of the non-randomised trials was questionable. Thirteen of the non-randomised studies were prospective and 36 reported on a consecutive series of patients. In eleven non-randomised studies the number of arteries, as opposed to the number of patients, was unclear.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised trials comparing carotid endarterectomy performed under local and general anaesthetic. Non-randomised studies suggest potential benefits with the use of local anaesthetic, but these studies may be biased.

Carotid endarterectomy

Carotid endarterectomy (CEA) is performed to prevent embolic stroke in patients with atheromatous disease at the carotid bifurcation. There is now substantial evidence to support early operation in symptomatic patients, ideally within 2 weeks of the last neurological symptoms. Thus, the anaesthetist may be faced with a high risk patient in whom there has been limited time for preoperative preparation. The operation may be performed under local or general anaesthesia. The advantages and disadvantages of both are explored in this review. Carotid shunting may offer a degree of cerebral protection, but carries its own risks and has not been proved to reduce morbidity and mortality. The use of carotid shunts is based on clinical judgement, awake neurological monitoring, and the use of monitors of cerebral perfusion. There is no ideal monitor of cerebral perfusion in the patient receiving general anaesthesia. Both the intraoperative and postoperative periods may be witness to dramatic haemodynamic changes that may compromise the cerebral or myocardial circulations. In particular, postoperative hypotension may compromise both myocardial and cerebral perfusion, and severe hypertension can cause cerebral hyperperfusion. There is as yet limited evidence to guide the management of these problems. In summary, CEA can yield significant benefit, but those with the most to gain from the operation also present the greatest challenge to the anaesthetist.

[Cerebral monitoring with somatosensory evoked potentials in carotid surgery. A review of 141 carotids]

OBJECTIVE

To evaluate postoperative and mid-term results of carotid surgery (CS) with somatosensory evoked potentials (SEP) monitoring.

METHODS

Between 1998 and 2006, 141 CS in 124 patients were performed under general anesthesia. Selective shunting was based on SEP abnormality. Shunting criteria were: reduction up to 50% of the amplitude or latency increasing up to 10%. Early results and follow-up data are analyzed retrospectively.

RESULTS

Shunting rate was 6%, 3 strokes (two transient strokes) occurred and one patient died of perioperative myocardial ischemia. The cumulative stroke and death rate at 30 days was 1.4%.

CONCLUSIONS

Intra-operative SEP monitoring with selective shunting may be safely performed in carotid surgery.

Cerebral Monitoring of Somatosensory Evoked Potentials during Carotid Surgery: A Review of 100 Cases

The purpose of this study was to evaluate immediate and middle-term results of surgical carotid artery revascularization (CAR) with cerebral monitoring of intraoperative somatosensory evoked potentials (SEPs). Between 1998 and 2004, a total of 100 CARs in 86 patients were performed under general anesthesia with SEP monitoring. A shunt was inserted if SEP amplitude decreased by 50% or latency time increased by 10%. Immediate and middle-term results were analyzed retrospectively. The shunt insertion rate was 5%. Two transient ischemic attacks were observed, and one patient died postoperatively due to myocardial infarction. The cumulative stroke and death rate was 1% at 30 days. Intraoperative SEP monitoring with selective shunt placement can be used safely for carotid surgery. Randomized studies will be necessary to determine the respective indications for various cerebral monitoring techniques.

Cerebral Ischemia during Carotid Artery Cross-Clamping: Predictive Value of Phase-Contrast Magnetic Resonance Imaging

The goal of this prospective study was to determine the utility of preoperative cerebral magnetic resonance imaging (MRI) in predicting cerebral ischemia during carotid artery cross-clamping for endarterectomy. Between January 2000 and December 2003, a total of 121 patients (95 men, 26 women) underwent three-dimensional phase-contrast MRI to assess collateral function prior to carotid endarterectomy. During regional anesthesia, patients were monitored to detect ischemic events and their timing in relation to cross-clamping and to determine mean intraoperative arterial pressure. These findings were then correlated with the collateral variations observed in the circle of Willis on preoperative MRI. Patients were classified into three groups according to neurological tolerance: normal tolerance (n = 106), immediate severe deficit (n = 9), and late deficit associated with arterial hypotension (n = 6). In the second group, a significant correlation was found between the absence of collateral circulation and neurological deficit (p < .0001). These results indicated that three-dimensional phase-contrast MRI is useful for predicting cerebral ischemia during carotid cross-clamping and selecting indications for shunting. Absence of visible collaterals of the circle of Willis on MRI is significantly predictive of early ischemia and an indication for systematic shunt placement.

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.

Defining the high-risk patient for carotid endarterectomy: An analysis of the prospective National Surgical Quality Improvement Program database

BACKGROUND

Carotid endarterectomy (CEA) is the gold standard for the treatment of carotid stenosis, but carotid angioplasty and stenting has been advocated in high-risk patients. The definition of such a population has been elusive, particularly because the data are largely retrospective. Our study examined results for CEA in the National Surgical Quality Improvement Program database (both Veterans Affairs and private sector).

METHODS

National Surgical Quality Improvement Program data were gathered prospectively for all patients undergoing primary isolated CEA during the interval 2000 to 2003 at 123 Veterans Affairs and 14 private sector academic medical centers. Study end points included the 30-day occurrence of any stroke, death, or cardiac event. A variety of clinical, demographic, and operative variables were assessed with multivariate models to identify risk factors associated with the composite (stroke, death, or cardiac event) end point. Adjudication of end points was by trained nurse reviewers (previously validated).

RESULTS

A total of 13,622 CEAs were performed during the study period; 95% were on male patients, and 91% of cases were conducted within the Veterans Affairs sector. The average age was 68.6 +/- 0.1 years, and 42.1% of the population had no prior neurologic event. The composite stroke, death, or cardiac event rate was 4.0%; the stroke/death rate was 3.4%. Multivariate correlates of the composite outcome were (odds ratio, P value) as follows: deciles of age (1.13, .018), insulin-requiring diabetes (1.73, <.001), oral agent-controlled diabetes (1.39, .003), decade of pack-years smoking (1.04, >.001), history of transient ischemic attack (1.41, >.001), history of stroke (1.51, >.001), creatinine >1.5 mg/dL (1.48, >.001), hypoalbuminemia (1.49, >.001), and fourth quartile of operative time (1.44, >.001). Cardiopulmonary comorbid features did not affect the composite outcome in this model. Regional anesthesia was used in 2437 (18%) cases, with a resultant relative risk reduction for stroke (17%), death (24%), cardiac event (33%), and the composite outcome (31%; odds ratio, 0.69; P = .008).

CONCLUSIONS

Carotid endarterectomy results across a spectrum of Veterans Affairs and private sector hospitals compare favorably to contemporary studies. These data will assist in selecting patients who are at an increased risk for adverse outcomes. Use of regional anesthetic significantly reduced perioperative complications in a risk-adjusted model, thus suggesting that it is the anesthetic of choice when CEA is performed in high-risk patients.

Cerebral hyperperfusion syndrome

Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy is characterised by ipsilateral headache, hypertension, seizures, and focal neurological deficits. If not treated properly it can result in severe brain oedema, intracerebral or subarachnoid haemorrhage, and death. Knowledge of CHS among physicians is limited. Most studies report incidences of CHS of 0-3% after carotid endarterectomy. CHS is most common in patients with increases of more than 100% in perfusion compared with baseline after carotid endarterectomy and is rare in patients with increases in perfusion less than 100% compared with baseline. The most important risk factors in CHS are diminished cerebrovascular reserve, postoperative hypertension, and hyperperfusion lasting more than several hours after carotid endarterectomy. Impaired autoregulation as a result of endothelial dysfunction mediated by generation of free oxygen radicals is implicated in the pathogenesis of CHS. Treatment strategies are directed towards regulation of blood pressure and limitation of rises in cerebral perfusion. Complete recovery happens in mild cases, but disability and death can occur in more severe cases. More information about CHS and early institution of adequate treatment are of paramount importance in order to prevent these potentially severe complications.

The value of phase-contrast magnetic resonance angiography of the circle of Willis in predicting cerebral ischemia-hypoxia (shunt need) during carotid endarterectomy

BACKGROUND

Cerebral perfusion during carotid cross-clamping depends on collateral function of the circle of Willis. The aim of this study was to determine the value of 3D Phase-Contrast (3D PC) MR angiography in predicting pre-operatively the need of shunting.

METHODS

3D PC MR angiography were performed in 121 patients before carotid endarterectomy under locoregional anaesthesia. Based on the MR analysis, the risk of cerebral ischemia-hypoxia during clamping was classified as high, moderate and low. The analysis was then correlated with intraoperative neurological examination.

RESULTS

In patients with high risk of cerebral ischemia (n=9), immediate cerebral ischemia developed in all patients within one min of clamping (P<0.001). All nine underwent shunt placement. In six of the patients with moderate risk (n=46), cerebral ischemia occurred between 20 and 25 min after clamping; All occurred during intraoperative hypotension.

CONCLUSION

3D PC MR angiography can significantly determine the need of shunting in patients with important risk of immediate intraoperative cerebral ischemia. It also focuses on the intraoperative blood pressure stability in patients with moderate risk of ischemia.

A Modified Combined Approach to Operative Carotid and Coronary Artery Disease: 82 Cases in 8 Years

BACKGROUND

A significant number of patients undergoing coronary artery surgery have severe carotid artery disease. It is also true that up to half of the patients undergoing carotid endarterectomy (CEA) have severe treatable coronary lesions. This study aims to review data regarding 82 patients of combined approach in 8 years; the second half consists of 44 patients whose CEA was performed under local anesthesia. It compares results of the conventional and the modified approaches to simultaneous surgery.

METHODS

All 82 patients who planned to have a concomitant procedure were recorded prospectively between 1995 and 2003. From 1998, the surgical technique has been modified to switch to local anesthesia for CEA, rather than perform under a single general anesthetic period. All pre-and perioperative data as well as in-hospital and outpatient control (mid- to long-term) data were recorded. A P-value of less than .05 was considered as significant. Analysis of survival was performed by using the Kaplan-Meier method and the log-rank test.

RESULTS

The 30-day follow-up was 100% complete for all patients. All patients were followed for 59.59 to 114 months) months postoperatively. Three patients (6.8%) in the modified and 2 (5.2%) in the standard group had intraluminal shunting (P > .05). In the standard group, 3 patients expired and 3 had perioperative stroke; only 1 patient had a stroke in the modified group and two expired (P > .05). Mean survival time according to Kaplan-Meier test was 109.97, SE 2.84, 95% CI (104.41-115.52) months for the former group, whereas it was 62.79, SE 1.20, 95% CI (60.4565.13) months for the latter. Actuarial estimates of survival during ten-year follow up were 94.44% SE 3.83 in ten-year follow-ups and 97.67% SE 2.30 in 5-year follow-ups for the modified group (P > .05).

CONCLUSIONS

Avoidance from extended periods of general anesthesia and cardiopulmonary bypass periods as well as immediate recognition of impaired cerebral flow during CEA and the time it provides to take preventive measures are the most important benefits of the modified technique without significantly changing hospital and long-term mortality and stroke. It may also reduce the cost and the waiting period for the suffering patient.

Compliance matching stent placement in the carotid artery of the swine promotes optimal blood flow and attenuates restenosis

OBJECTIVES

We assessed the value of a gradient-compliant stent in an animal model.

METHODS

Bilateral carotid arteries were stented with nitinol stents having variable-oversizing, variable-stiffness, and with (CMS, 10 animals) and without (SMART, four animals) compliance-matching endings. Angiography, hemodynamic, scanning-electron-microscopic and histological analyses were performed at 3-month. The protocol was completed in 14 among 19 swines.

RESULTS

Transient (1-month) exaggerated recoil, attributable to stress-induced phasic inhibition of vasorelaxation, developed at CMS endings. At mid-term, all stents were endothelialized; CMS-stents, but not SMART-stents, were incorporated into walls (one-strut-thickness). Restenosis developed outside SMART-stents (cell migration+wall-compensatory enlargement) whereas CMS-stents elicited no or focalized cell-accumulations at endings that bulged vascular walls radially outward. SMART-stents were blood-flow neutral, whereas CMS-stents favored (higher-stiffness, higher-oversizing) or opposed (lower-stiffness, less-oversizing) carotid blood flow.

CONCLUSIONS

Direct carotid stenting with stents having compliance-matched endings and specific requirements of stiffness and oversizing can optimize blood flow to the brain and restrict local restenosis.

Intraoperative management: carotid endarterectomies

The management of anesthesia for patients undergoing carotid endarterectomy is challenging and dynamic. Effective management and good outcome requires the anesthesiologist's understanding of cerebral physiology, knowledge of neck anatomy, and understanding of the rapid pathophysiologic changes that occur during carotid artery manipulations. The anesthesiologist must be flexible in the management of patients, who frequently have underlying multiorgan pathology and cardiovascular compromise. Good communication between the anesthetic and surgical teams is needed to avoid irreversible debilitating consequences for the patient.