Local versus general anaesthesia in carotid endarterectomy: a systematic review of the evidence

Locoregional Versus General Anesthesia in Prolonged Carotid Endarterectomy: A Propensity Score-Matched Study from the American College of Surgeons National Surgical Quality Improvement Program Database from 2011 to 2022

BACKGROUND

Carotid endarterectomy (CEA) is an effective treatment for carotid stenosis. Previous studies yielded conflicting findings regarding postoperative outcomes after CEA when comparing those under general and locoregional anesthesia. However, these findings may be influenced by an inherent selection bias, as general anesthesia is frequently selected for more complex CEA. To counteract this selection bias, this study compared the 30-day outcomes of locoregional and general anesthesia in patients who underwent prolonged CEA.

METHODS

Adult patients undergoing CEA were identified in American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP)-targeted database from 2011 to 2022. Only cases with prolonged operative times (over third quartile) were selected. Patients who had symptomatic and asymptomatic carotid stenosis were examined separately. A 1:3 propensity score matching was used to address preoperative differences between patients under locoregional and general anesthesia to assess 30-day postoperative outcomes. Moreover, factors associated with prolonged CEA were identified by multivariable logistic regression.

RESULTS

Among symptomatic patients who underwent prolonged CEA, 246 and 4,286 were under locoregional and general anesthesia, respectively. In asymptomatic patients, 388 had locoregional anesthesia and 5,137 had general anesthesia. After propensity score matching, patients under locoregional and general anesthesia had comparable 30-day mortality (symptomatic: 1.63% vs. 0.81%, P = 0.28; asymptomatic: 0.77% vs. 0.52%, P = 0.70) and stroke (symptomatic: 4.88% vs. 4.34%, P = 0.72; asymptomatic: 1.29% vs. 1.46%, P = 1.00). All other 30-day outcomes were comparable between groups, except for symptomatic patients under locoregional had shorter operation time (P < 0.01) and asymptomatic patients under locoregional had lower cranial nerve injury (2.06% vs. 4.90%, P = 0.02). High-risk anatomical factors, male sex, younger age, and certain comorbidities were associated with prolonged operative times.

CONCLUSIONS

Patients under both types of anesthesia had mostly comparable 30-day postoperative outcomes, including mortality and stroke, for both symptomatic and asymptomatic patients. Therefore, locoregional and general anesthesia appear to be equally effective in CEA cases characterized by anticipated complexity and, consequently, prolonged operative times.

Influence of Anatomic Conditions on Efficacy and Safety of Combined Intermediate Cervical Plexus Block and Perivascular Infiltration of Internal Carotid Artery in Carotid Endarterectomy: A Prospective Observational Trial

Ultrasound-guided intermediate cervical plexus blockade with perivascular infiltration of the carotid artery bifurcation perivacular block (PVB) is a reliable technique for regional anesthesia in carotid endarterectomy (CEA). We investigated the effect of the carotid bifurcation level (CBL) on PVB efficacy and safety in patients undergoing CEA. This prospective observational cohort study included 447 consecutive CEA patients who received PVB over a 6-y period. Vascular and neurologic puncture-related complications were recorded. The CBL was localized at the low level (C4 and C5 vertebra, low-level [LL] group) in 381 (85.2%) patients and at the high level (C2 and C3 vertebra, high-level [HL] group) in 66 (14.8%) patients. Local anesthetic supplementation by surgeons was necessary in 64 (14.3%) patients in the LL group and 38 (59.4%) patients in the HL group (p < 0.001) and was associated with a higher rate of central neurologic complications in the HL group (p = 0.031). Therefore, the efficacy of the PVB may be influenced by the CBL.

A Machine Learning Approach for Predicting Early Phase Postoperative Hypertension in Patients Undergoing Carotid Endarterectomy

BACKGROUND

This study aimed to establish and validate a machine learning-based model for the prediction of early phase postoperative hypertension (EPOH) requiring the administration of intravenous vasodilators after carotid endarterectomy (CEA).

METHODS

Perioperative data from consecutive CEA procedures performed from January 2013 to August 2019 were retrospectively collected. EPOH was defined in post-CEA patients as hypertension involving a systolic blood pressure above 160 mm Hg and requiring the administration of any intravenous vasodilator medications in the first 24 hr after a return to the vascular ward. Gradient boosted regression trees were used to construct the predictive model, and the featured importance scores were generated by using each feature's contribution to each tree in the model. To evaluate the model performance, the area under the receiver operating characteristic curve was used as the main metric. Four-fold stratified cross-validation was performed on the data set, and the average performance of the 4 folds was reported as the final model performance.

RESULTS

A total of 406 CEA operations were performed under general anesthesia. Fifty-three patients (13.1%) met the definition of EPOH. There was no significant difference in the percentage of postoperative stroke/death between patients with and without EPOH during the hospital stay. Patients with EPOH exhibited a higher incidence of postoperative cerebral hyperperfusion syndrome (7.5% vs. 0, P < 0.001), as well as a higher incidence of cerebral hemorrhage (3.8% vs. 0, P < 0.001). The gradient boosted regression trees prediction model achieved an average AUC of 0.77 (95% CI 0.62 to 0.92). When the sensitivity was fixed near 0.90, the model achieved an average specificity of 0.52 (95% CI 0.28 to 0.75).

CONCLUSIONS

We have built the first-ever machine learning-based prediction model for EPOH after CEA. The validation result from our single-center database was very promising. This novel prediction model has the potential to help vascular surgeons identify high-risk patients and reduce related complications more efficiently.

Anesthesia type determines risk of cerebral infarction after carotid endarterectomy

OBJECTIVE

Silent and symptomatic cerebral infarctions occur in up to 34% of patients after carotid endarterectomy (CEA). This prospective study compared the risk of new brain infarctions detected by magnetic resonance imaging (MRI) in patients with internal carotid artery stenosis undergoing CEA with local anesthesia (LA) vs general anesthesia (GA).

METHODS

Consecutive patients with internal carotid artery stenosis indicated for CEA were screened at two centers. Patients without contraindication to LA or GA were randomly allocated to the LA or GA group by ZIP code randomization. Brain MRI was performed before and 24 hours after CEA. Neurologic examination was performed before and 24 hours and 30 days after surgery. The occurrence of new infarctions on the control magnetic resonance images, stroke, transient ischemic attack, and other complications was statistically evaluated.

RESULTS

Of 210 randomized patients, 105 underwent CEA with LA (67 men; mean age, 68.3 ± 8.1 years) and 105 with GA (70 men; mean age, 63.4 ± 7.5 years). New infarctions were more frequently detected on control magnetic resonance images in patients after CEA under GA compared with LA (17.1% vs 6.7%; P = .031). Stroke or transient ischemic attack occurred within 30 days of CEA in three patients under GA and in two under LA (P = 1.000). There were no significant differences between the two types of anesthesia in terms of the occurrence of other complications (14.3% for GA and 21.0% for LA; P = .277).

CONCLUSIONS

The risk of silent brain infarction after CEA as detected by MRI is higher under GA than under LA.

Ultrasound-guided superficial cervical plexus block under dexmedetomidine sedation versus general anesthesia for carotid endarterectomy: a retrospective pilot study

Background

Carotid endarterectomy (CEA) has been performed under regional and general anesthesia (GA). The general anesthesia versus local anesthesia for carotid surgery study compared the two techniques and concluded that there was no difference in perioperative outcomes. However, since this trial, new sedative agents have been introduced and devices that improve the delivery of regional anesthesia (RA) have been developed. The primary purpose of this pilot study was to compare intraoperative hemodynamic stability and postoperative outcomes between GA and ultrasound-guided superficial cervical plexus block (UGSCPB) under dexmedetomidine sedation for CEA.

Methods

Medical records from 43 adult patients who underwent CEA were retrospectively reviewed, including 16 in the GA group and 27 in the RA group. GA was induced with propofol and maintained with sevoflurane. The UGSCPB was performed with ropivacaine under dexmedetomidine sedation. We compared the intraoperative requirement for vasoactive drugs, postoperative complications, pain scores using the numerical rating scale, and the duration of hospital stay.

Results

There was no difference between groups in the use of intraoperative antihypertensive drugs. However, intraoperative inotropic and vasopressor agents were more frequently required in the GA group (p<0.0001). In the GA group, pain scores were significantly higher during the first 24 h after surgery (p<0.0001 between 0-6 h, p<0.004 between 6-12 h, and p<0.001 between 12-24 h). The duration of hospital stay was significantly more in the GA group (13.3±4.6 days in the GA group vs. 8.5±2.4 days in the RA group, p<0.001).

Conclusion

In this pilot study, intraoperative hemodynamic stability and postoperative outcomes were better in the RA compared to the GA group.

Perioperative Interventions to Modify Risk of Morbidity and Mortality

Perioperative myocardial ischemia is the single most important, potentially reversible risk factor for mortality and cardiovascular complications during and after noncardiac surgery. The influence of anesthetic choices and techniques on cardiac risk in noncardiac surgery is difficult to ascertain because of the low incidence of morbid cardiac outcomes in the surgical population as a whole. This article summarizes several areas (eg, perioperative βblockade, glucose management, and perioperative hemodynamics) that have been addressed in well-designed clinical trials.

[Secondary prevention of ischemic non cardioembolic stroke]

Stroke patients are at high risk for recurrence or new occurrence of other cardiovascular events or cardiovascular mortality. It is estimated that a high percentage of non-cardioembolic ischemic stroke can be prevented by a suitable modification of lifestyle (diet and exercise), reducing blood pressure (BP) with antihypertensive medication, platelet aggregation inhibitors, statins and high intake reducing consumption of. Unfortunately the degree of control of the different risk factors in secondary prevention of stroke is low. The clinical practice guidelines show clear recommendations with corresponding levels of evidence, but only if implemented in a general way they will get a better primary and secondary stroke prevention.

Carotid endarterectomy under local and/or regional anesthesia has less risk of myocardial infarction compared to general anesthesia: An analysis of national surgical quality improvement program database

Multiple studies have evaluated the effect of anesthesia type on carotid endarterectomy with inconsistent results. Our study compared 30-day postoperative myocardial infarction, stroke, and mortality between carotid endarterectomy under local or regional anesthesia and carotid endarterectomy under general anesthesia utilizing National Surgical Quality Improvement Program database. All patients listed in National Surgical Quality Improvement Program database that underwent carotid endarterectomy under general anesthesia and local or regional anesthesia from 2005 to 2011 were included with the exception of patients undergoing simultaneous carotid endarterectomy and coronary artery bypass grafting. The data revealed substantial differences between the two groups compared, and these were adjusted using multiple logistic regression. Postoperative myocardial infarction, stroke, and death at 30 days were compared between the two groups. A total of 42,265 carotid endarterectomy cases were included. A total of 37,502 (88.7%) were performed under general anesthesia and 4763 (11.3%) under local or regional anesthesia. Carotid endarterectomy under local or regional anesthesia had a significantly decreased risk of 30-day postoperative myocardial infarction when compared to carotid endarterectomy under general anesthesia (0.4% vs 0.86%, p = 0.012). No statistically significant differences were found in postoperative stroke or mortality. Carotid endarterectomy under local or regional anesthesia carries a decreased risk of postoperative myocardial infarction when compared to carotid endarterectomy under general anesthesia. Therefore, patients at risk of postoperative myocardial infarction undergoing carotid endarterectomy, consideration of local or regional anesthesia may reduce that risk.

Rate and prognosis of patients under conscious sedation requiring emergent intubation during neuroendovascular procedures

BACKGROUND AND PURPOSE

Neuroendovascular procedures are performed with the patient under conscious sedation (local anesthesia) in varying numbers of patients in different institutions, though the risk of unplanned conversion to general anesthesia is poorly characterized. Our aim was to ascertain the rate of failure of conscious sedation in patients undergoing neuroendovascular procedures and compare the in-hospital outcomes of patients who were converted from conscious sedation to general anesthesia with those whose procedures were initiated with general anesthesia.

MATERIALS AND METHODS

All patients who had an endovascular procedure initiated under general anesthesia or conscious sedation were identified through a prospective data base maintained at 2 comprehensive stroke centers. Patient clinical and procedural characteristics, in-hospital deaths, and favorable outcomes (modified Rankin Scale score, 0-2) at discharge were ascertained.

RESULTS

Nine hundred seven endovascular procedures were identified, of which 387 were performed with the patient under general anesthesia, while 520 procedures were initiated with conscious sedation. Among procedures initiated with intent to be performed under conscious sedation, 9 (1.7%) procedures required emergent conversion to general anesthesia. Favorable clinical outcome and in-hospital mortality in patients requiring emergent conversion from conscious sedation to general anesthesia and in those with procedures initiated with general anesthesia were not statistically different (42% versus 50%, P = .73 and 17% versus 13%, P = 1.00, respectively).

CONCLUSIONS

In our study, there was a very low rate of conscious sedation failure and associated adverse outcomes among patients undergoing neuroendovascular procedures. Proper patient selection is important if procedures are to be performed with the patient under conscious sedation. Limitations of the methodology used in our study preclude us from offering specific recommendations regarding when to use a specific anesthetic protocol.

General or Local Anesthesia for Carotid Endarterectomy—The “Real-World” Experience

Perioperative complications from carotid endarterectomy (CEA) are the main drawbacks of the procedure. The aim of this study was to assess the complication rates in patients undergoing CEA under general anesthesia (GA) or regional anesthesia (local anesthesia [LA]) at our institution. Patients undergoing CEA at our regional vascular unit between 2000 and 2004 were included. Data were collated retrospectively from a prospective database. Follow-up was up to 62 months. In all, 383 endarterectomies were performed, 260 of which were under LA. Outcome measures included 30-day death (2.1%), stroke (1.8%), and combined stroke and death (2.8%). A 30-day incidence of stroke, death, and combined stroke and death was lower in the LA group. Incidence of myocardial infarction and transient ischemic attacks, and annual mortality were higher in the LA group. No significant difference was found between the 2 groups. In a unit where CEA is preferentially performed under LA, anesthesia technique failed to significantly influence outcome.

Meta-analysis of small randomized controlled trials in surgery may be unreliable

Background

Meta-analysis of randomized controlled trials (RCTs) should provide reliable evidence about the effects of interventions. This may be less reliable when only small trials are available.

Methods

The sample size was determined for all surgical RCTs included in Cochrane Collaboration systematic reviews. The difficulty in interpreting meta-analysis of small trials is illustrated using two specific reviews.

Results

The typical sample size for surgical RCTs was small with a median of only 87 participants. Only 39·8 per cent had adequate prerandomization treatment allocation concealment. In both systematic reviews that were assessed in detail, statistically significant early results from meta-analysis of several small RCTs did not reliably predict the results of subsequent RCTs.

Conclusion

Surgical RCTs tend to be small and underpowered. Meta-analysis of such trials does not necessarily produce reliable results.

[Brachial plexus block for minimally invasive parathyroidectomy: report of 3 cases]

The brachial plexus block, either deep or superficial, is one of the anesthetic techniques used in parathyroidectomy. The block is easy to perform and has few hemodynamic side effects. Surgery can be carried out in an awake patient. We describe 3 cases of patients with primary hyperparathyroidism (parathyroid adenoma) who underwent unilateral minimally invasive parathyroidectomy under regional anesthesia and sedation with 2 mg of midazolam plus remifentanil at dosages ranging from 0.6 to 0.1 microg kg(-1) min(-1). To provide a deep cervical block, we administered 15 mL of 0.75% ropivacaine. For a superficial block, 15 mL of 0.2% ropivacaine was used. The procedure could be completed in all 3 patients under regional anesthesia. The latency time for the block ranged from 21 to 30 minutes, and remifentanil dosages from 0.05 to 0.09 microg kg(-1) min(-1) were administered for procedures that lasted 30 to 45 minutes. No patient required postoperative opioids or antiemetics, although a local anesthetic had to be used at the moment of incision for 1 patient. All 3 patients were discharged the same day. We wish to underline the utility of the brachial plexus block for parathyroid surgery. The technique is easy to perform, safe, and effective; as a result, surgery can be carried out on an outpatient basis.

Improving the outcome of carotid endarterectomy

Little benefit from local anaesthesia

The Superficial Cervical Plexus Block for Postoperative Pain Therapy in Carotid Artery Surgery. A Prospective Randomised Controlled Trial

OBJECTIVES

Rapid and reliable neurological evaluation soon after carotid artery surgery is feasible with modern methods of general anesthesia, but postoperative pain therapy remains a challenge. Use of opioids can mask neurological deficits. We investigated whether superficial cervical plexus block reduced postoperative opioid consumption after carotid endarterectomy.

DESIGN

Prospective, randomised, double-blinded, placebo controlled trial.

METHODS

46 patients undergoing unilateral carotid endarterectomy under general anesthesia were randomized to either superficial cervical block with ropivacaine (n=23) or placebo (n=23). A patient controlled analgesia device (PCA) delivering morphine was provided for all patients. Subjective pain levels (visual analog scale, VAS) were recorded. The primary outcome was total morphine consumption on discharge from the recovery room. Secondary outcomes included arterial pCO2 (as an indicator of central nervous effects of morphine) and patient satisfaction.

RESULTS

No adverse effects of the superficial cervical plexus block were reported. Four patients in the placebo group were excluded because of other drug use post-operatively. Per protocol analysis compared 23 patients in ropivacaine group and 19 patients in the placebo group. The ropivacaine group had a significant reduction in morphine consumption (3.8+/-2.0 versus 12.9+/-4.0, p<0.001), lower maximal pain scores (2.6+/-2.0 versus 5.8+/-1.6, p<0.001), and paCO2 levels (39.0+/-2.6 versus 41.9+/-3.4, p=0.008) at discharge from the recovery room. Patient satisfaction (1=very good to 6=insufficient) was substantially higher in the ropivacaine group (1.7+/-0.7 versus 3.1+/-1.2, p<00.01).

CONCLUSION

The significant and clinically relevant lower morphine consumption and pain score, as well as the substantially higher patient satisfaction demonstrate that superficial cervical plexus block provides effective pain relief for patients undergoing carotid endarterectomy.

Regional versus general anaesthesia for carotid endarterectomy: impact of change in practice

BACKGROUND

Local anaesthesia (LA) for carotid endarterectomy (CEA) may offer advantages over general anaesthesia (GA).

AIM

Our aim was to compare outcome from CEA before and after changing our anaesthetic technique from GA to LA.

METHODS

Sequential patients who underwent CEA between January 1997 and December 2001 were identified from a prospectively collected database. GA was used during the first two years of this period and LA was used exclusively over the last three years. Differences in the incidence of intraoperative shunting, perioperative stroke and transient ischaemic attack (TIA), cranial nerve injury, neck haematoma, perioperative death and duration of hospital stay were assessed.

RESULTS

Three hundred and seventy one CEAs were carried out in 363 patients, 179 under GA and 192 under LA. Indications were TIAs (140), stroke with recovery (134), amaurosis fugax (85) and asymptomatic high-grade stenosis (12). Intraoperative shunting was used in 66 (37%) GA operations and 36 (18.8%) LA operations (p<0.01). There were nine strokes and four transient neurological events; 10 (5.5%) patients developed such problems with GA and three (1.6%) with LA (p<0.05). There were four deaths, three (1.7%) after GA and one (0.5%) after LA (p=NS). Duration of hospital stay was less in the LA group at a median (range) of three days (2-10) compared with 4.5 (3-14) days in the GA group (p<0.001).

CONCLUSION

Employing LA rather than GA for CEA has been associated with a reduction in intraoperative shunting and perioperative stroke, and the duration of hospital stay. LA appears to offer clinical and possible cost advantages over GA.

Carotid endarterectomy in cervical block anesthesia in patients with occluded contralateral internal carotid artery

Introduction: The goal of modern carotid surgery is relief of symptoms, stroke prevention, improvement in quality of life, prevention of vascular dementia, and prolongation of lifetime. OBJECTIVE: The objective of this paper was to compare the outcome of carotid endarterectomy in cervical block vs. general anesthesia in patients with occluded contralateral internal carotid artery (ICA). METHOD: One hundred patients (76 male, 24 female, mean age 60.81 years) with occluded contralateral ICA were operated from 1997-2000. Neurological symptomatology, deficiency and stroke incidence were preoperatively analyzed in two groups. Duplex-scanning, angiograms and CT-scan confirmed the diagnosis. Risk factors analysis included hypertension, diabetes, lipid metabolism disorders, smoking and history of CAD, CABG and PAOD. Morbidity and mortality were used to compare the outcome of surgery in two groups. RESULTS There was no difference of age, gender and symptomatology between the groups. Paresis, TIA and dysphasia were most frequent. 70%-90% of ICA stenosis was seen in the majority of patients. Hypertension and smoking were dominant risk factors in these two groups. Eversion carotid end arterectomy was the most frequent technique used. In three cases out of nine that were operated under cervical block, the neurological symptoms developed just after clamping, so the intra-luminal shunt was placed. Postoperative morbidity was 12% and mortality was 8%. Conclusion: There was no difference of preoperative parameters, surgical technique and outcome in these two groups. Without other intraoperative monitoring, cervical block anesthesia might be an option in patients with the occlusion of the contralateral ICA. However, prospective studies involving more patients are needed.

Clinical and operative predictors of outcomes of carotid endarterectomy

OBJECTIVE

The net benefit for patients undergoing carotid endarterectomy is critically dependent on the risk of perioperative stroke and death. Information about risk factors can aid appropriate selection of patients and inform efforts to reduce complication rates. This study identifies the clinical, radiographic, surgical, and anesthesia variables that are independent predictors of deaths and stroke following carotid endarterectomy.

METHODS

A retrospective cohort study of patients undergoing carotid endarterectomy in 1997 and 1998 by 64 surgeons in 6 hospitals was performed (N = 1972). Detailed information on clinical, radiographic, surgical, anesthesia, and medical management variables and deaths or strokes within 30 days of surgery were abstracted from inpatient and outpatient records. Multivariate logistic regression models identified independent clinical characteristics and operative techniques associated with risk-adjusted rates of combined death and nonfatal stroke as well as all strokes.

RESULTS

Death or stroke occurred in 2.28% of patients without carotid symptoms, 2.93% of those with carotid transient ischemic attacks, and 7.11% of those with strokes (P < .0001). Three clinical factors increased the risk-adjusted odds of complications: stroke as the indication for surgery (odds ratio [OR], 2.84; 95% confidence interval [CI] = 1.55-5.20), presence of active coronary artery disease (OR, 3.58; 95% CI = 1.53-8.36), and contralateral carotid stenosis > or =50% (OR, 2.32; 95% CI = 1.33-4.02). Two surgical techniques reduced the risk-adjusted odds of death or stroke: use of local anesthesia (OR, 0.30; 95% CI = 0.16-0.58) and patch closure (OR, 0.43; 95% CI = 0.24-0.76).

CONCLUSIONS

Information about these risk factors may help physicians weigh the risks and benefits of carotid endarterectomy in individual patients. Two operative techniques (use of local anesthesia and patch closure) may lower the risk of death or stroke.

Regional anaesthesia and propofol sedation for carotid endarterectomy

BACKGROUND

Many surgeons now perform carotid endarterectomy under regional anaesthesia. The aim of the present study was to review a sedation technique using a computer-controlled infusion of propofol.

METHODS

A consecutive series of 84 carotid endarterectomies done by a single surgeon and commenced under regional anaesthesia with sedation was studied. There were 54 men and 27 women (three bilateral procedures), with a median age of 71 years (range 48-87 years). All patients had carotid stenosis > 70% 80 procedures were done for symptomatic disease and three asymptomatic patients were treated before cardiac surgery (one bilateral).

RESULTS

Seventy-seven procedures were completed under regional anaesthesia and sedation alone; seven required conversion to general anaesthetic, usually for intolerance of the operation. An intraoperative shunt was required on only four occasions (5%). Postoperatively eight patients required critical care monitoring, usually for blood pressure control. The remainder were nursed on the vascular ward, and 68% were discharged home on the day after surgery. No patient died, but there were two neurological complications. One patient had a cerebellar stroke 10 days after surgery, but recovered fully after 4 months. A second developed cerebral oedema due to severe intraoperative hypertension and required intensive care for 15 days. He too recovered fully. Five patients had a further episode of transient cerebral ischaemia within 1 month of operation, but in all cases duplex imaging showed a widely patent carotid and there were no sequelae.

CONCLUSION

Target controlled propofol infusion is an effective method of sedation in patients undergoing carotid endarterectomy.

Increased oxygen administration during awake carotid surgery can reverse neurological deficit following carotid cross-clamping

We describe the management of two patients undergoing awake carotid surgery who developed signs of cerebral ischaemia following cross-clamping of the internal carotid artery. Administration of oxygen 100% with a close-fitting anaesthetic facemask reversed the neurological deficit, avoiding the need for insertion of an internal carotid artery shunt. Thus, the incidence of shunt insertion, which is reduced by the use of regional rather than general anaesthesia, could be reduced further by supplementary oxygenation. The possible mechanism and implications are discussed.

Improvements in carotid endarterectomy in Scotland: results of a national prospective survey

BACKGROUND AND AIMS

The effectiveness of carotid endarterectomy (CEA) depends upon selection of patients with a high absolute risk of stroke, avoidance of delays from intial presentation to surgery and provsion of surgery with a low perioperative risk of stroke. We evaluated these aspects of practice in Scottish hospitals and, by encouraging adherence to national (SIGN) guidelines, attempted to improve the effectiveness of CEA.

METHODS

Prospective independent survey of patient selection, pre-operative delays and surgical performance for all CEAs performed in Scottish National Health Service hospitals over two 13 month periods from September 1997 and February 1999 respectively.

RESULTS

Thirteen hospitals performed 485 CEAs in the first period and 392 in the second, equating to an overall annual rate of 79 per million population. During both periods at least 95% of patients reported symptoms of carotid terittory ischaemia, but the proportion with stenoses greater than >70% rose from 89% to 97% (p<0.0001). The delays between referral, surgical consultation and subsequent surgery fell significantly but remained unacceptably long. The proportion seen by the surgeon within two weeks of referral rose from 36% to 43% (p=0.05) and the proportion operated on within one month thereafter rose from 35% to 49% (p<.0001). The perioperative combined major stroke and death rate was 3% in both periods.

CONCLUSION

We demonstrated significant changes in practice, in line with national guidelines, which would be expected to improve the effectiveness of our national programme of CEA. There is further scope for improving performance, particularly in relation to pre-operative delays.

Intracerebral Haemorrhage Following Carotid Endarterectomy

OBJECTIVES

To determine risk factors for the development of hyperperfusion and intra-cerebral haemorrhage following carotid endarterectomy and formulate potential protocols for prevention.

METHODS

MEDLINE database search of the English language literature (1966-2002) was performed using the words 'cerebral haemorrhage', 'intracranial haemorrhage' and 'carotid endarterectomy'. Other articles were cross-referenced by hand.

RESULTS

There are no data from randomised trials confirming the significance of any single risk factor. The evidence suggests that the following may have a role: pre-operative hypertension, recent ipsilateral non-haemorrhagic stroke, previous ischaemic cerebral infarction, surgery for a > 90% ipsilateral internal carotid artery (ICA) stenosis, impaired cerebrovascular reserve, intra-operative haemodynamic or embolic ischaemia, post-operative hypertension, an ipsilateral increase of > or =175% in peak middle cerebral artery velocity (MCAV) and/or a > or =100% increase in pulsatility index.

CONCLUSIONS

A critical ICA stenosis with impaired cerebrovascular reserve resulting in maximal intracerebral vasodilatation and post-operative hyperperfusion (impaired autoregulation) appear to be central to the development of ICH. Appropriate pre-operative screening and post-operative monitoring in high risk patients might identify those who would benefit from manipulation of the haemodynamic events that appear to promote ICH.

Neurological Evaluation by Intraoperative Wake-up During Carotid Endarterectomy Under General Anesthesia

Although general anesthesia allows relief from stressors such as pain, discomfort, or anxiety for patients undergoing carotid endarterectomy, neurologic assessment is less reliable than under local anesthesia. We describe a unique anesthetic management strategy for carotid endarterectomy patients incorporating the advantages of both general and local anesthesia. The technique allows thorough assessment of neurologic function during carotid cross-clamping by intraoperative wake-up, and guarantees airway management by tracheal intubation.

Patient Satisfaction for Carotid Endarterectomy Performed under Local Anaesthesia

OBJECTIVES

To develop, validate and use a procedure specific questionnaire to evaluate patient experience and satisfaction following carotid endarterectomy (CEA) under either general (GA) or local anaesthesia (LA).

METHODS

Twenty post-CEA patients were interviewed. Data were content analysed and recurrent themes used to generate the specific carotid endarterectomy experience questionnaire (CEA-EQ). The CEA-EQ consists of 15 pre-op and 13 postoperative questions. Validity was established by correlation with the FRS Patient Satisfaction with Surgical Services (SSSQ) and State form of the State Trait Anxiety Inventory (STAI-S) in 69 patients (35 LA, 34 GA). Subsequently 88 patients randomised to GA CEA and 88 to LA CEA received the CEA-EQ. A local anaesthetic intraoperative experience questionnaire (LA-EQ) was also developed and given to LA patients only.

RESULTS

Validity was confirmed through significant correlations with the STAI-S (r=0.67, p<0.001) and the SSSQ (r=0.44, p<0.001). In the randomised prospective study response rates were greater than 90%. Overall experience and satisfaction with CEA was high. There was no statistically significant difference in anxiety, satisfaction or overall experience between anaesthetic techniques. LA CEA was associated with a significantly better perception of recovery. The majority of LA patients found the procedure acceptable.

CONCLUSIONS

The CEA-EQ is a valid tool to assess qualitative aspects of CEA patient care. Overall satisfaction and experience with CEA is good and not related to anaesthetic technique. LA CEA is not associated with any increased anxiety, is tolerated by the majority of patients and is associated with a better perception of recovery.

Perioperative stress response to carotid endarterectomy: The impact of anesthetic modality

OBJECTIVE

Surgery for extracranial carotid artery disease has been challenged by carotid angioplasty stenting because the latter is less invasive and avoids surgical trauma. In fact, the magnitude of the perioperative stress response evoked by carotid endarterectomy (CEA) has never been evaluated. Our aim was to determine the degree of surgical trauma caused by CEA and to define differences related to the use of locoregional or general anesthesia.

METHODS

We prospectively studied 113 consecutive CEAs performed on 109 patients admitted at a community institutional center. Patients were stratified for demographics and risk factors and operated on under locoregional (LA) or general anesthesia (GA) depending on both the surgeon preference and patient's compliance. Selective carotid shunting was performed for patients who manifested neurologic deficits under LA or had stump pressure values </=30 mm Hg under GA. Markers of the stress response, including cortisol, adrenocorticotropic hormone, prolactin, and C-reactive protein, were measured intraoperatively, before and after carotid artery cross-clamping (CACC), and postoperatively up to the third day after surgery. Hemodynamic variability was assessed during surgery and for 24 hours postoperatively. Operative times were also measured. Surgeons were considered as independent variables for stress response. Statistics were run by means of nonparametric tests and univariate and multivariate analysis with a linear regression model.

RESULTS

CEA was performed under GA in 63 cases (55.8%) and under LA in 50 (44.2%). The two groups were comparable in terms of demographics and risk factors. Intraoperatively, cortisol and adrenocorticotropic hormone levels were significantly higher in the LA group (both P <.001). CACC increased the intraoperative cortisol levels in both the GA (P =.019) and the LA groups (P =.006). However, in patients who underwent carotid shunting, this effect was abolished (GA group, P =.779; LA group, P = 1.0). During the early postoperative period there was no difference between the two groups. On postoperative day 1 the stress response was abolished in both groups. Prolactin levels increased intraoperatively in both the LA and GA groups and returned within preoperative values on postoperative day 1. Prolactin levels were higher in the GA group (P =.003 intraoperatively and P <.001 postoperatively). C-reactive protein significantly increased in both GA and LA groups on postoperative days 1 and 2 and started to decrease on day 3 with no differences between the two groups at any time. Hemodynamic variability and considered risk factors including individual surgeon were not significant variables. Gender-related differences were found only in prolactin secretion. The length of surgery had an impact for procedures that lasted >120 minutes. Three patients experienced an intraoperative neurologic event and had higher post-CACC cortisol values as compared to asymptomatic patients.

CONCLUSIONS

Intraoperative surgical stress was higher under LA and was blunted by carotid shunting under both LA and GA. Within 2 hours after surgery the anesthetic modality no longer had any impact on surgical trauma. The stress response to CEA, regardless of the type of anesthesia, was abolished within 24 hours. Intraoperative stress response, namely hypercortisolemia, directly correlated with subclinical and clinical cerebral hypoperfusion/ischemia during CACC. Hence, attenuation of the stress response to CEA might decrease the incidence of cerebral ischemic events.

Seizures after carotid endarterectomy: hyperperfusion, dysautoregulation or hypertensive encephalopathy?

OBJECTIVES

Presentation, management and outcome following seizure after carotid endarterectomy (CEA). MATERIALS AND DESIGN: Prospective audit.

RESULTS

Eight patients (0.8%) suffered a seizure (three bilateral) <30 days following 949 CEAs. Seizure was not associated with age, gender or presentation. Seven were treated hypertensives but four had labile BP pre-operatively. Five had severe bilateral carotid disease and four had vertebral/subclavian stenoses. Six had a >50% drop in middle cerebral artery blood flow velocity (MCAV) with clamping. Only three had >100% increase in MCAV with flow restoration. Five required treatment for post-operative hypertension. Two suffered seizures <36 hrs of CEA, the remainder were at 3-8 days. All eight had significantly elevated blood pressure at onset of seizures. Four underwent immediate MCAV monitoring and each was elevated. Emergency CT scanning/autopsy showed normal scans (n = 3), white matter oedema (n = 3), oedema and diffuse haemorrhage (n = 1), intracranial haemorrhage (n = 1). Seven developed a post-ictal neurological deficit (stroke = 5, TIA = 2). Overall, two patients either died or suffered a disabling stroke.

CONCLUSIONS

Post-CEA seizure was associated with adverse outcome. Most were labile hypertensives with severe bilateral carotid/vertebral disease. MCAV changes suggested poor collateral recruitment, but no consistent pattern of early hyperperfusion emerged. It remains uncertain whether high MCAVs and severe hypertension after seizure onset are cause or effect. Clinicians treating these patients in acute medical units were generally unaware of the "post-CEA hyperperfusion syndrome" and tended to treat the hypertension less aggressively.

Association of sex with perioperative mortality and morbidity after carotid endarterectomy for asymptomatic carotid stenosis

OBJECTIVE

To examine whether perioperative morbidity and mortality after carotid endarterectomy depend on the sex and the presence of symptoms on presentation.

DESIGN

Retrospective review of quality assurance database prospectively collected.

SETTING

A university teaching hospital.

PARTICIPANTS

One thousand two hundred eighty-seven patients who had 1,503 carotid endarterectomies from 1990 to 1999 from a quality assurance database.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The cases were divided into 4 groups by sex and symptoms on presentation: male-symptomatic (MS), male-asymptomatic (MA), female-symptomatic (FS), and female-asymptomatic (FA). The 4 groups were compared for preoperative demographic and comorbidity profiles, carotid plaque characteristics, and outcome. Outcome measures included in-hospital stroke, myocardial infarction (MI), congestive heart failure (CHF), and death. There were 496 cases in the MS group, 407 in the MA group, 315 in the FS group, and 285 in the FA group. Women were less likely to have a history of coronary artery disease, prior MI, or smoking, and their carotid plaques were less likely to be ulcerated or contain intraplaque hemorrhage. Even when controlling for the comorbidities and plaque characteristics, the incidence of each of the complications examined was low and not significantly different between the sexes in both the symptomatic and asymptomatic groups. The rate of stroke or death was 3.0% (MS) versus 1.9% (FS) (p = NS) and 1.2% (MA) versus 1.8% (FA) (p = NS).

CONCLUSION

There is no significant sex difference in perioperative cardiac or cerebrovascular complications. Women with symptomatic or asymptomatic carotid stenosis can have acceptably low complication rates from carotid endarterectomy and may benefit from the surgery as much as men.

Carotid Endarterectomy Using Regional Anesthesia: A Benchmark for Stenting

Regional block (RB) anesthesia for carotid surgery offers the advantage of continuously monitoring the awake patient's neurologic status during carotid cross-clamping. We retrospectively studied our experience with RB for carotid endarterectomy (CEA) procedures performed during the period January 1, 1995 through December 31, 2001. A total of 388 consecutive CEA procedures were performed; RB was used in 314 and general anesthesia (GA) in 74. Three patients required conversion from RB to GA. GA was used only in patients who could not tolerate a block or needed combined coronary artery bypass grafting (CABG) and carotid surgery. New ipsilateral stroke did not occur in RB patients; one patient extended a previous stroke. Three in-hospital deaths occurred; these were all cardiac-related. In GA patients undergoing CEA without CABG (CEA only, n = 58), one stroke and no deaths occurred. The combined stroke and mortality rate for all CEA-only patients was 1.3 per cent (five of 372). RB allows 90 per cent of procedures to be performed without shunting, thus facilitating endarterectomy and patch angioplasty. CEA performed under RB is similar to carotid stenting because both procedures allow monitoring of the awake patient's neurologic status. The very low procedural complication rate in this study warrants the consideration of carotid surgery under regional block as a benchmark for future carotid angioplasty and stenting studies.

Respiratory complications associated with anesthesia

Adverse pulmonary outcomes that follow anesthesia and surgery are often attributed to anesthesia care. PPCs are a significant concern for anesthesia caregivers because they use drugs and techniques that temporarily decrease lung volume, impair airway reflexes, limit immune function, and depress secretion mobilization. A significant component of perioperative risk derives from the surgical site, postoperative pain, and effects of pharmacologic pain management. Rapidly evolving surgical and anesthesia techniques and the introduction of newer pharmaceutical agents make it difficult to identify best practice from retrospective experience reported in the perioperative literature. Prospective studies that deal with specific patient populations, incomparable patient groups or techniques, and unique practice bias have limited validity of claims regarding several promising approaches to perioperative risk reduction. In the absence of clear scientific principles, a perioperative pulmonary risk management strategy for the early part of this century is based on the consensus practice of informed clinicians (Box 4).