Local versus general anaesthesia for carotid endarterectomy

Eversion technique versus traditional carotid endarterectomy with patch angioplasty: a systematic review with meta-analyses and trial sequential analysis

Introduction

The use of an 'eversion' technique is not unequivocally proven to be superior to carotid endarterectomy with patch angioplasty. An up-to-date systematic review is needed for evaluation of benefits and harms of these two techniques.

Methods

RCTs comparing eversion technique versus endarterectomy with patch angioplasty in patients with a symptomatic and significant (≥50 %) stenosis of the internal carotid artery were enrolled. Primary outcomes were all-cause mortality rate, health-related quality of life and serious adverse events. Secondary outcomes included 30-day stroke and mortality rate, (a) symptomatic arterial occlusion or restenosis, and adverse events not critical for decision making.

Results

Four RCTs were included with 1272 surgical procedures for carotid stenosis; eversion technique n = 643 and carotid endarterectomy with patch closure n = 629. Meta-analysis comparing both techniques showed, with a very low certainty of evidence, that eversion technique might decrease the number of patients with serious adverse events (RR 0.47; 95% CI 0.34 to 0.64; p ≤ 0.01). However, no difference was found on the other outcomes. TSA demonstrated that the required information sizes were far from being reached for these patient-important outcomes. All patient-relevant outcomes were at low certainty of evidence according to GRADE.

Conclusions

This systematic review showed no conclusive evidence of any difference between eversion technique and carotid endarterectomy with patch angioplasty in carotid surgery. These conclusions are based on data obtained in trials with very low certainty according to GRADE and should therefore be interpreted cautiously. Until conclusive evidence is obtained, the standard of care according to ESVS guidelines should not be abandoned.

Carotid endarterectomy with patch angioplasty versus primary closure in patients with symptomatic and significant stenosis: a systematic review with meta-analyses and trial sequential analysis of randomized clinical trials

BACKGROUND

Patch angioplasty in conventional carotid endarterectomy is suggested to reduce the risk of restenosis and recurrent ipsilateral stroke compared with primary closure. A systematic review of randomized clinical trials is needed to compare outcomes (benefits and harms) of both techniques.

METHODS

Searches (CENTRAL, PubMed/MEDLINE, EMBASE, and other databases) were last updated 3rd of January 2021. We included randomized clinical trials comparing carotid endarterectomy with patch angioplasty versus primary closure of the arterial wall in patients with a symptomatic and significant (> 50%) carotid stenosis. Primary outcomes are defined as all-cause mortality and serious adverse events.

RESULTS

We included 12 randomized clinical trials including 2187 participants who underwent 2335 operations for carotid stenosis comparing carotid endarterectomy with patch closure (1280 operations) versus carotid endarterectomy with primary closure (1055 operations). Meta-analysis comparing carotid endarterectomy with patch angioplasty versus carotid endarterectomy with primary closure may potentially decrease the number of patients with all-cause mortality (RR 0.53; 95% CI 0.26 to 1.08; p = 0.08, best-case scenario for patch), serious adverse events (RR 0.73; 95% CI 0.56 to 0.96; p = 0.02, best-case scenario for patch), and the number of restenosis (RR 0.41; 95% CI 0.23 to 0.71; p < 0.01). Trial sequential analysis demonstrated that the required information sizes were far from being reached for these patient-important outcomes. All the patient-relevant outcomes were at low certainty of evidence according to The Grading of Recommendations Assessment, Development, and Evaluation.

CONCLUSIONS

This systematic review showed no conclusive evidence of a difference between carotid endarterectomy with patch angioplasty versus primary closure of the arterial wall on all-cause mortality, < 30 days mortality, < 30 days stroke, or any other serious adverse events. These conclusions are based on data from 15 to 35 years ago, obtained in trials with very low certainty according to GRADE, and should be interpreted cautiously. Therefore, we suggest conducting new randomized clinical trials patch angioplasty versus primary closure in carotid endarterectomy in symptomatic patients with an internal carotid artery stenosis of 50% or more. Such trials ought to be designed according to the Standard Protocol Items: Recommendations for Interventional Trials statement (Chan et al., Ann Intern Med 1:200-7, 2013) and reported according to the Consolidated Standards of Reporting Trials statement (Schulz et al., 7, 2010). Until conclusive evidence is obtained, the standard of care according to guidelines should not be abandoned.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014013416 . Review protocol publication 2019 DOI: https://doi.org/10.1136/bmjopen-2018-026419 .

Plexus anesthesia versus general anesthesia for carotid endarterectomy: A systematic review with meta-analyses

INTRODUCTION

Traditional carotid endarterectomy is considered to be the standard technique for prevention of a new stroke in patients with a symptomatic carotid stenosis. Use of plexus anesthesia or general anesthesia in traditional carotid endarterectomy is, to date, not unequivocally proven to be superior to one other. A systematic review was needed for evaluation of benefits and harms to determine which technique, plexus anesthesia or general anesthesia is more effective for traditional carotid endarterectomy in patients with symptomatic carotid stenosis.

METHODS

The review was conducted according to our protocol following the recommendations of Cochrane and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Searches were updated on the October 1, 2020. We did not find any randomized clinical trial comparing plexus anesthesia and general anesthesia in carotid endarterectomy with patch angioplasty matching our protocol criteria in patients with a symptomatic and significant (≥50%) carotid stenosis.

CONCLUSIONS

Based on the current, high risk of bias evidence, we concluded there is a need for new randomized clinical trials with overall low risk of bias comparing plexus anesthesia with general anesthesia in carotid endarterectomy with patch closure of the arterial wall in patients with a symptomatic and significant (≥50%) stenosis of the internal carotid artery.Protocol unique identification number (UIN): CRD42019139913, (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=139913).

Eversion technique versus conventional endarterectomy with patch angioplasty in carotid surgery: protocol for a systematic review with meta-analyses and trial sequential analysis of randomised clinical trials

INTRODUCTION

Traditional carotid endarterectomy is considered to be the standard technique for prevention of a new stroke in patients with a symptomatic carotid stenosis. Use of patch angioplasty to restore the arterial wall after longitudinal endarterectomy is, to date, not unequivocally proven to be superior to eversion technique. A systematic review is needed for evaluation of benefits and harms of the eversion technique versus the traditional endarterectomy with patch angioplasty in patients with symptomatic carotid stenosis.

METHODS AND OUTCOMES

The review will be conducted according to this protocol following the recommendations of the 'Cochrane Handbook for Systematic Reviews' and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Randomised clinical trials comparing eversion technique versus endarterectomy with patch angioplasty in patients with a symptomatic stenosis of the internal carotid artery will be included. Primary outcomes are all-cause mortality rate, health-related quality of life and serious adverse events. Secondary outcomes are 30-day stroke and mortality rate, symptomatic arterial restenosis or occlusion and non-serious adverse events. The databases Cochrane Central Register of Controlled Trials, PubMed/MEDLINE and EMBASE will be searched (November 2019). We will primarily base our conclusions on meta-analyses of trials with overall low-risk of bias. We will use trial sequential analysis to assist the evaluation of imprecision in Grading of Recommendations, Assessment, Development and Evaluation. However, if pooled point estimates of all trials are similar to pooled point estimates of trials with overall low risk of bias and there is lack of a statistical significant interaction between estimates from trials with overall high risk of bias and trials with overall low risk of bias we will consider the trial sequential analysis adjusted precision of the estimate achieved in all trials as the result of our meta-analyses.

ETHICS AND DISSEMINATION

The proposed systematic review will collect and analyse data from published studies, therefore, ethical approval is not required. The results of the review will be disseminated by publication in a peer-review journal and submitted for presentation at conferences.

PROSPERO REGISTRATION NUMBER

CRD42019119361.

Plexus anesthesia versus general anesthesia in patients for carotid endarterectomy with patch angioplasty: Protocol for a systematic review with meta-analyses and Trial Sequential Analysis of randomized clinical trials

INTRODUCTION

Traditional carotid endarterectomy is considered to be the standard technique for prevention of a new stroke in patients with a symptomatic carotid stenosis. Use of plexus anesthesia or general anesthesia in traditional carotid endarterectomy is, to date, not unequivocally proven to be superior to one other. A systematic review is needed for evaluation of benefits and harms to determine which technique, plexus anesthesia or general anesthesia is more effective for traditional carotid endarterectomy in patients with symptomatic carotid stenosis.

METHODS AND OUTCOMES

The review will be conducted according to this protocol following the recommendations of the 'Cochrane Handbook for Systematic Reviews' and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Randomized Clinical Trials comparing plexus anesthesia versus general anesthesia in traditional carotid endarterectomy will be included. Primary outcomes will be postoperative death and/ or stroke (<30 days) and serious adverse events. Secondary outcomes will be non-serious adverse events.We will primarily base our conclusions on meta-analyses of trials with overall low risk of bias. We will use Trial Sequential Analysis to assist the evaluation of imprecision in Grading of Recommendations Assessment, Development and Evaluation. However, if pooled point-estimates of all trials are similar to pooled point-estimates of trials with overall low risk of bias and there is lack of a statistical significant interaction between estimates from trials with overall high risk of bias and trials with overall low risk of bias we will consider the Trial Sequential Analysis adjusted confidence interval precision of the estimate achieved in all trials as the result of our meta-analyses.

ETHICS AND DISSEMINATION

The proposed systematic review will collect and analyze secondary data from already performed studies therefore ethical approval is not required. The results of the systematic review will be disseminated by publication in a peer-review journal and submitted for presentation at relevant conferences.

Lactate/pyruvate monitoring during carotid endarterectomy under general anaesthesia versus cervical plexus block: A randomised controlled study

BACKGROUND AND AIMS

Carotid endarterectomy (CEA) reduces the risk of stroke in patients with significant carotid stenosis and may be performed under general anaesthesia (GA) or regional anaesthesia (RA). This study aimed to compare RA and GA with regard the jugular venous bulb blood lactate and pyruvate levels.

METHODS

This randomised-controlled trial was done between October-2013 and September-2015. Thirty-six patients were randomised into either GA or RA groups, with six excluded after randomisation. In the RA group, combined deep and superficial cervical plexus blocks were performed. In the GA group, anaesthesia was induced with propofol and fentanyl. In both groups, monitoring of neurological function was done. Sampling of the contralateral jugular bulb blood was done. The main outcome measures were lactate and pyruvate in the jugular venous blood. For comparing categorical data, Chi-square test was used, and for the numerical variables, t-test was used.

RESULTS

Demographics were comparable in the two Groups. Serum lactate and pyruvate levels were higher in the GA group than RA group. At 120 min under anaesthesia, lactate and pyruvate levels under RA vs. GA, respectively were 0.76±0.03 mEq/L vs. 1.14±0.06, p-0.001 mEq/L, and 0.08± 0.00 mEq/L vs. 0.10±0.01 mEq/L, p=0.006. Lactate/ pyruvate ratios were normal in both groups. The mean blood pressure was significantly lower in the GA group during anaesthesia.

CONCLUSION

In patients undergoing Carotid endarterectomy, serum levels of both lactate and pyruvate were higher under general versus regional anaesthesia.

Randomized controlled trials: still the backbone of vascular surgery?

Prior to the introduction of evidence-based medicine, decision-making was largely based upon ‘intuitive reasoning’, whereby senior clinicians dictated practice based upon personal dogma, personal experience and (often) biased observational studies. This era began to end (in vascular surgery) following completion of the landmark randomized trials in carotid disease, which recruited patients throughout the 1980s. Despite scepticism amongst some surgeons of the time these particular randomized trials have stood the test of time and remain the cornerstone of virtually every guideline of practice to this day. The carotid randomized trials became a beacon for using ‘evidence’ rather than ‘intuitive reasoning’ and randomized trials have now been used to determine optimal practice in a plethora of carotid surgery and stenting trials, lower limb revascularization and numerous aortic aneurysm based studies.

The literature abounds with situations where practice (previously based on observational study data) was changed overnight following publication of a well-designed randomized trial. However, while observational studies are prone to selection bias, randomized trials bring their own unique limitations including problems with external validity, they take too long to complete, they are very expensive, they are notorious for problems with recruitment and they can frequently become obsolete. This has led to a (not unreasonable) call for more observational studies to be used in the development of practice guidelines. Unfortunately, the principle guideline bodies around the world, e.g. National Institute for Health and Care Excellence (NICE) and the American Heart Association (AHA), prioritize randomized trial evidence above all else. Until that changes, guideline makers will find it very difficult to deviate from using historical randomized trial evidence, even when high quality observational data suggest that ‘real world’ practice bears little comparison to that reported in the randomized trials. Nowhere is that more evident than in developing contemporary guidelines for the management of asymptomatic carotid disease.

A Prospective Nonrandomized Study on Carotid Surgery Performed under General Anesthesia without Intraoperative Cerebral Monitoring

BACKGROUND

The purpose of this study was to assess our experience of carotid surgery habitually performed under general anesthesia without intraoperative intracerebral monitoring, and following a pre-established perioperative protocol, which includes extensive use of an intraoperative shunt (IOS).

METHODS

This study included 311 consecutive carotid operations performed over 32 months. This patient cohort represents 14% of our total experience in carotid surgery (2219 operations, major stroke/mortality rate: 1.4%). The IOS was inserted routinely in the presence of intraoperative blood pressure instability during cross-clamping and when the predictable clamping time might have exceeded 20 minutes. A moderate and stable hypertension was maintained throughout surgery without IOS.

RESULTS

Overall, 120 (38.6%) endarterectomies were performed with primary closure, 73 (23.5%) with eversion technique, 113 (36.3%) with patch angioplasty, and 5 (1.6%) with other techniques. Out of 113 patch angioplasties, 111 (98.2%) were performed with an IOS. This was utilized in only 3 cases of direct carotid reconstructions or other carotid endarterectomy techniques (1.5%). Overall, the IOS placement rate was 36.7%. Postoperatively, 2 major strokes (.64%), 2 minor strokes (.64%), 4 hyperperfusion syndromes (1.3%), and no mortality were recorded. No cases of cross-clamp ischemia/shunt-related perioperative strokes were observed.

CONCLUSIONS

The low perioperative stroke rate reported in this prospective study proves the advantages of wide use of IOS during carotid surgery. This coupled with a large experience in carotid surgery and close monitoring and support of blood pressure, are the major determinants of these results that demonstrate the low risk of shunt-related complications for surgeons who regularly utilize an IOS.

Intraoperative management of carotid endarterectomy

First reports on surgical treatment of cerebrovascular atherosclerosis date to the early 1950s. With advancements in surgical technique, carotid endarterectomy (CEA) has become the treatment of choice for patients with both symptomatic and asymptomatic severe carotid stenosis. Given the benefits that surgery offers beyond medical management, the number of CEA procedures continues to increase. The intraoperative management of patients undergoing CEA is challenging because of the combination of patient and surgical factors. This article explores and reviews the literature on anesthetic management and considerations of patients undergoing CEA.

Protecting the anaesthetised brain

The anaesthetized brain is vulnerable to ischaemic insults, which could result in neurological deficits ranging from neuropsychological disturbances to stroke and even death. The risk of perioperative brain injury is relatively high in cardiac, neurosurgical and major vascular surgery, although it has also rarely been reported in noncardiac nonneurosurgical operations. Besides underlying risk factors such as cerebrovascular disease, advanced age, and cardiovascular disease, anaesthesia and surgery per se could also be a contributory factor. The anaesthesiologist plays a pivotal role in protecting the anaesthetized brain, both by taking preventive measures and instituting brain protection strategies. Despite advances and breakthroughs in pharmacological neuroprotection in the laboratory, currently there is no drug, anaesthetic or non-anaesthetic, which is available for clinical use. The anaesthesiologist has to rely on non-pharmacological modalities and neuromonitoring to prevent intraoperative brain injury

Recommendations for management of patients with carotid stenosis

Stroke is a one of the leading causes of morbidity and mortality in the world. Carotid atherosclerosis is recognized as an important factor in stroke pathophysiology and represents a key target in stroke prevention; multiple treatment modalities have been developed to battle this disease. Multiple randomized trials have shown the efficacy of carotid endarterectomy in secondary stroke prevention. Carotid stenting, a newer treatment option, presents a less invasive alternative to the surgical intervention on carotid arteries. Advances in medical therapy have also enabled further risk reduction in the overall incidence of stroke. Despite numerous trials and decades of clinical research, the optimal management of symptomatic and asymptomatic carotid disease remains controversial. We will attempt to highlight some of the pivotal trials already completed, discuss the current controversies and complexities in the treatment decision-making, and postulate on what likely lies ahead. This paper will highlight the complexities of decision-making optimal treatment recommendations for patients with symptomatic and asymptomatic carotid stenosis.

Analysis of the evidence behind the ESVS guidelines for the invasive treatment of carotid stenosis

The European Society for Vascular Surgery has recently published updated guidelines for the invasive treatment of carotid disease. The recommendations were rated according to the level of evidence (A: randomized controlled trials, B: well-conducted clinical studies, C: expert opinion). The following document summarizes the evidence on which these recommendations were based, in order to keep physicians from various disciplines updated on the advances in the field of the invasive management of carotid disease.

General anaesthesia versus local anaesthesia for carotid surgery (GALA): a multicentre, randomised controlled trial

BACKGROUND

The effect of carotid endarterectomy in lowering the risk of stroke ipsilateral to severe atherosclerotic carotid-artery stenosis is offset by complications during or soon after surgery. We compared surgery under general anaesthesia with that under local anaesthesia because prediction and avoidance of perioperative strokes might be easier under local anaesthesia than under general anaesthesia.

METHODS

We undertook a parallel group, multicentre, randomised controlled trial of 3526 patients with symptomatic or asymptomatic carotid stenosis from 95 centres in 24 countries. Participants were randomly assigned to surgery under general (n=1753) or local (n=1773) anaesthesia between June, 1999 and October, 2007. The primary outcome was the proportion of patients with stroke (including retinal infarction), myocardial infarction, or death between randomisation and 30 days after surgery. Analysis was by intention to treat. The trial is registered with Current Control Trials number ISRCTN00525237.

FINDINGS

A primary outcome occurred in 84 (4.8%) patients assigned to surgery under general anaesthesia and 80 (4.5%) of those assigned to surgery under local anaesthesia; three events per 1000 treated were prevented with local anaesthesia (95% CI -11 to 17; risk ratio [RR] 0.94 [95% CI 0.70 to 1.27]). The two groups did not significantly differ for quality of life, length of hospital stay, or the primary outcome in the prespecified subgroups of age, contralateral carotid occlusion, and baseline surgical risk.

INTERPRETATION

We have not shown a definite difference in outcomes between general and local anaesthesia for carotid surgery. The anaesthetist and surgeon, in consultation with the patient, should decide which anaesthetic technique to use on an individual basis.

FUNDING

The Health Foundation (UK) and European Society of Vascular Surgery.

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.

GALA: an international multicentre randomised trial comparing general anaesthesia versus local anaesthesia for carotid surgery

Background

Patients who have severe narrowing at or near the origin of the internal carotid artery as a result of atherosclerosis have a high risk of ischaemic stroke ipsilateral to the arterial lesion. Previous trials have shown that carotid endarterectomy improves long-term outcomes, particularly when performed soon after a prior transient ischaemic attack or mild ischaemic stroke. However, complications may occur during or soon after surgery, the most serious of which is stroke, which can be fatal. It has been suggested that performing the operation under local anaesthesia, rather than general anaesthesia, may be safer. Therefore, a prospective, randomised trial of local versus general anaesthesia for carotid endarterectomy was proposed to determine whether type of anaesthesia influences peri-operative morbidity and mortality, quality of life and longer term outcome in terms of stroke-free survival.

Methods/design

A two-arm, parallel group, multicentre randomised controlled trial with a recruitment target of 5000 patients. For entry into the study, in the opinion of the responsible clinician, the patient requiring an endarterectomy must be suitable for either local or general anaesthesia, and have no clear indication for either type. All patients with symptomatic or asymptomatic internal carotid stenosis for whom open surgery is advised are eligible. There is no upper age limit. Exclusion criteria are: no informed consent; definite preference for local or general anaesthetic by the clinician or patient; patient unlikely to be able to co-operate with awake testing during local anaesthesia; patient requiring simultaneous bilateral carotid endarterectomy; carotid endarterectomy combined with another operation such as coronary bypass surgery; and, the patient has been randomised into the trial previously. Patients are randomised to local or general anaesthesia by the central trial office. The primary outcome is the proportion of patients alive, stroke free (including retinal infarction) and without myocardial infarction 30 days post-surgery. Secondary outcomes include the proportion of patients alive and stroke free at one year; health related quality of life at 30 days; surgical adverse events, re-operation and re-admission rates; the relative cost of the two methods of anaesthesia; length of stay and intensive and high dependency bed occupancy.

Trial registration

Current Controlled Trials ISRCTN00525237

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.

Effects of clonidine and superficial cervical plexus block on hemodynamic stability after carotid endarterectomy

OBJECTIVES

To evaluate the effects of 2 interventions (intravenous clonidine and superficial cervical block) on hemodynamic stability after carotid endarterectomy and to identify variables associated with hemodynamic instability.

DESIGN

Prospective, observational study, sequential enrollment.

SETTING

University hospital.

PARTICIPANTS

Two hundred seventy-five patients undergoing elective carotid endarterectomy under general anesthesia.

INTERVENTIONS

Group NN (n = 50) received no intervention. In group CN (n = 85), 3 mug/kg of clonidine were administered intravenously 30 minutes before the end of the operation. Group CB (n = 140) additionally received a superficial cervical plexus block (SCB) with 20 mL of naropine 0.5% before the induction of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Clonidine alone (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.45-3.76) and clonidine combined with an SCB (OR, 4.99; 95% CI, 3.19-7.82) resulted in a significant increase in hemodynamic stability after CEA (p < 0.001) from 53.3% (NN) to 70.0% (CN) and 83.3% (CB), respectively. The need for rescue medication decreased from 40.0% to 17.6% and 13.6% (p < 0.001). Both interventions significantly reduced the need for postoperative opioid analgesics (p < 0.01). Logistic regression analysis showed preoperative systolic blood pressure values greater than 170 mmHg (OR, 3.23; 95% CI, 1.76-5.93), previous cardiac interventions (OR, 3.3; 95% CI, 1.54-7.11), and the need for rescue medication in the awakening period (OR, 5.8; 95% CI, 2.88-11.52) to be independent risk factors for postoperative hemodynamic instability (p < or = 0.002).

CONCLUSIONS

Intravenous clonidine and superficial cervical block significantly improve cardiovascular stability after carotid endarterectomy. Patients with pre-existing excessive hypertension and previous coronary interventions must be considered a high-risk group.

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.

Limited search strategies were effective in finding relevant nonrandomized studies

BACKGROUND AND OBJECTIVE

Searching for nonrandomized studies in electronic databases is complicated because there is a variety of study designs and lack of standardization in the terminology. The purpose of this study was to develop and evaluate a method to limit search strategies according to study design of comparative nonrandomized studies (cNRSs).

METHODS

Four updated Cochrane systematic reviews that included nonrandomized studies (cohort, case-control, and cross-sectional studies) of the effects of health care interventions were selected. Search strategies limited to study design were devised for each one of these topic areas in two electronic databases (MEDLINE and EMBASE). A progressive method (PM) and a fixed method for selecting the most appropriate search terms associated with study design of nonrandomized studies are suggested.

RESULTS

The results showed that the sensitivity of search strategies (in two databases combined) limited to study design were between 90% and 100% for the PM using both controlled vocabulary (CV) and textwords (TWs) and between 95% and 100% for a fixed set of controlled vocabulary and TWs.

CONCLUSIONS

It is possible and acceptable to use search strategies limited to study design of cNRSs of health care interventions.

Methodological shortcomings predicted lower harm estimates in one of two sets of studies of clinical interventions

OBJECTIVES

High quality harms data are necessary to appropriately assess the balance between benefits and harms of interventions. Little is known, however, about whether perceived methodological shortcomings are associated with lower estimates of harms.

STUDY DESIGN AND SETTING

Studies reporting harms associated with carotid endarterectomy (CEA) and rofecoxib were identified using published systematic reviews. A standardized abstraction form, including eight predefined criteria for assessing the quality of harms reporting, was used to extract data. Univariate and multivariate analyses were performed to empirically evaluate the association between quality criteria and estimates of harms.

RESULTS

In 111 studies of CEA, meeting five of the eight-quality criteria was associated with significantly higher adverse event rates. A quality-rating instrument with four criteria predicted adverse events (5.7% in studies rated "adequate," compared to 3.9% in studies rated "inadequate" [P=0.0003]). In multivariate analyses, the quality-rating assignment remained significant when controlling for other clinical and study-related variables. Different quality criteria, however, predicted estimates of risk for myocardial infarction in 16 trials of rofecoxib.

CONCLUSION

The presence of methodological shortcomings can predict lower estimates of serious harms. Clinicians and researchers should consider methodological shortcomings when evaluating estimates of harms associated with clinical interventions.