Carotid endarterectomy. A survey of UK anaesthetic practice

Carotid Endarterectomy with Local Anesthesia and LMA/General Anesthesia

There is no clear consensus as to the appropriate anesthetic technique for patients undergoing a carotid endarterectomy. Such patients may have comorbid conditions, such as coronary artery disease, hyperlipidemia, and others. The two main anesthetic approaches are general anesthesia, including an endotracheal tube, with neurological monitoring and regional anesthesia that allows for an awake patient to be assessed neurologically. The objective of our study was to evaluate a novel anesthetic technique that combined general anesthesia with a laryngeal mask airway (LMA) plus regional anesthesia in the form of bupivacaine injected into the surgical site. Anesthesia was maintained with desflurane 4%, so the patient emerged rapidly for neurological assessment at the conclusion of surgery. We report on a case of a 55-year-old patient who underwent a successful carotid endarterectomy using this hybrid technique of general anesthesia with LMA plus regional anesthesia. This technique was safe and effective and the patient experienced no complications other than a hematoma on the left neck that was likely the result of long-term use of aspirin and Plavix. While further study is warranted, this hybrid technique of general anesthesia with LMA plus regional anesthesia holds promise for carotid endarterectomy patients.

Carotid Endarterectomy: A Review

Background:

Since the validation of carotid endarterectomy (CEA) as an effective means of stroke prevention, there has been renewed interest in its best indications and methods, as well as in how it compares to carotid angioplasty and stenting (CAS). This review examines these topics, as well as the investigation of carotid stenosis and the role of auditing and reporting CEAresults.

Investigation:

Brain imaging with CTor MRI should be obtained in patients considered for CEA, in order to document infarction and rule out mass lesions. Carotid investigation begins with ultrasound and, if results agree with subsequent, good-quality MRAor CTangiography, treatment can be planned and catheter angiography avoided. An equally acceptable approach is to proceed directly from ultrasound to catheter angiography, which is still the gold-standard in carotid artery assessment.

Indications:

Appropriate patients for CEA are those symptomatic with transient ischemic attacks or nondisabling stroke due to 70-99% carotid stenosis; the maximum allowable stroke and death rate being 6%. Uncertain candidates for CEA are those with 50 - 69% symptomatic stenosis, and those with asymptomatic stenosis ≥ 60% but, if selected carefully on the basis of additional risk factors (related to both the carotid plaque and certain patient characteristics), some will benefit from surgery. Asymptomatic patients will only benefit if surgery can be provided with exceptionally low major complication rates (3% or less). Inappropriate patients are those with less than 50% symptomatic or 60% asymptomatic stenosis, and those with unstable medical or neurological conditions.

Techniques:

Carotid endarterectomy can be performed with either regional or general anaesthesia and, for the latter, there are a number of monitoring techniques available to assess cerebral perfusion during carotid cross-clamping. While monitoring cannot be considered mandatory and no single monitoring technique has emerged as being clearly superior, EEG is most commonly used. “Eversion” endarterectomy is a variation in surgical technique, and there is some evidence that more widely practiced patch closure may reduce the acute risk of operative stroke and the longer-term risk of recurrent stenosis.

Carotid angioplasty and stenting:

Experience with this endovascular and less invasive procedure grows, and its technology continues to evolve. Some experienced therapists have reported excellent results in case series and a number of randomized trials are now underway comparing CAS to CEA. However, at this time it is premature to incorporate CAS into routine practice replacing CEA.

Auditing:

It has been shown that auditing of CEA indications and results with regular feed-back to the operating surgeons can significantly improve the performance of this operation. Carotid endarterectomy auditing is recommended on both local and regional levels.

Regional anaesthesia for carotid endarterectomy: an audit over 10 years

BACKGROUND

The aim of this retrospective study was to compare the failure rates and the frequency of anaesthesia-related complications of two different methods of regional anaesthesia used for carotid endarterectomy--cervical epidural (CE) anaesthesia and cervical plexus block (CPB).

METHODS

The study included 1828 carotid endarterectomies performed in 1455 patients between 1996 and 2006. A combination of deep and superficial CPB was used for 1166 procedures, whereas in 662 cases surgery was performed under CE anaesthesia.

RESULTS

The failure rate of CPB was 3% compared with 6.9% for CE anaesthesia (P < 0.0001). The reasons for failure of the anaesthetic techniques were (1) technical failure, (2) insufficient analgesia, (3) non-compliant patients, and (4) anaesthetic complications. The incidence of complications resulting from CE anaesthesia was significantly higher than with CPB; life-threatening complications--2% compared with 0.3% (P < 0.0001); other anaesthesia-related complications 5.7 vs 4.7%. Serious complications included inadvertant injection into the subarachnoid space or vertebral artery. The frequency of shunt insertion, perioperative stroke, and death from any cause was similar in both groups of patients.

CONCLUSIONS

Both methods of regional anaesthesia are acceptable for carotid artery surgery. CPB is associated with a significantly lower frequency of anaesthesia-related complications and should therefore be considered the anaesthetic of choice. CE anaesthesia should not be performed except in extenuating circumstances such as variant anatomy or the requirement for more extensive surgery.

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.

Routine Shunting Is a Safe and Reliable Method of Cerebral Protection during Carotid Endarterectomy

The purpose of this report is to describe the perioperative and long-term outcomes of standard carotid endarterectomy (CEA) with general anesthesia, routine shunting, and patching and to show that routine shunting is a safe and reliable method of cerebral protection. Between January 1998 and December 2004, 700 patients attending our Department of Vascular Surgery underwent 786 CEAs performed using a standardized technique. Forty-four patients were excluded from the analysis because they underwent combined CEA and coronary artery bypass grafting, so the analysis is based on the results of 742 CEAs in 656 patients (86 bilateral CEAs). The strict surgical protocol included general anesthesia and standard carotid bifurcation endarterectomy with routine shunting (Javid's shunt) and Dacron patching. The Javid shunts were easily inserted in 738 cases (99.4%) but could not be used in four cases (0.5%) because of the presence of a very small internal carotid artery. The mean ischemic time required to insert the shunt and complete the suture was 4.7 min (+/-1.15), and the mean time to perform the endarterectomy was 34.3 min (+/-6.7). The mean follow-up was 24.4 months (+/-17.3). Overall 30-day mortality was 0.1% (one patient) due to a contralateral major stroke. The 1-month perioperative neurological complication rate was 0.7%, with three major and two minor strokes. The cumulative stroke and death rate was 0.8%. Preoperative symptoms such as hypertension, contralateral occlusion, or an age of more than 80 years were not independent risk factors for perioperative stroke. In the long-term follow-up, Kaplan-Meier analysis indicated an estimated 5-year stroke-free rate of 98.0%. There were eight cases (1%) of >70% restenosis (four cases) or thrombosis (four cases) of the operated internal carotid artery during the follow-up in asymptomatic patients: in four cases, carotid stenting due to >70% restenosis led to good results. The Kaplan-Meier estimate of the restenosis-free rate was 97.8%. The combined stroke and mortality rate of 0.8%, and the restenosis rate of 1% support the argument that standard CEA performed with routine shunting as brain protection leads to excellent early and long-term results.

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.

Intraoperative monitoring during vascular surgery

The principal objectives of intraoperative monitoring are to improve perioperative outcome, facilitate surgery and reduce adverse events, using continuously collected data of cardiopulmonary,neurologic and metabolic function to guide pharmacologic and physiologic therapy. Although sophisticated and reliable apparatus may be used to collect these data they are useless, or even harmful, without proper interpretation. This article provides a comprehensive overview of recent publications on the history,philosophy, and semantics of monitoring.

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.

Local Haemodynamic Changes During Carotid Endarterectomy—The Influence on Cerebral Oxygenation

OBJECTIVES

To characterize carotid bifurcation haemodynamics and cerebral oxygenation during clamping and at reperfusion after carotid endarterectomy (CEA).

MATERIALS AND METHODS

Sixty-two patients with a symptomatic high-grade stenosis of the internal carotid artery (ICA), who underwent CEA under general anaesthesia, were studied prospectively. Measurements of stump-pressure, volume flow (transit time flowmetry) and changes in cerebral oxygenation (near-infrared spectroscopy (NIRS)) were performed. Selective shunting was based on stump pressure only.

RESULTS

Stump pressure correlated with both ICA flow before clamping (r=0.45; p=0.03) and changes in cerebral oxygenation (rSO2) during clamping (r=0.61; p=0.002), the latter was reversed by shunt placement. ICA flow before clamping also correlated with changes in rSO2 during clamping (r=0.41; p=0.01).

CONCLUSION

Measurements with transit time flowmetry and cerebral oximetry are technically easy and help to determine the need for selective shunting during CEA. High ICA flow before clamping in combination with a low stump pressure usually indicates the need for a shunt. Volume flow measurements may also be useful in the quality assessment of the CEA.

Anaesthesia and endovascular surgery

Anaesthetic requirements for endovascular surgery for aortic, carotid and peripheral vascular disease are reviewed. Peculiarities of the surgery which may impinge on anaesthetic management are discussed together with the pre-operative assessment issues of particular relevance to patients with generalized vascular disease. The detailed anaesthetic management for carotid and aortic endovascular repair is addressed. The lowered peri-operative stress and general morbidity levels which occur with endovascular surgery allow sicker patients with greater risk factors to present for this type of surgery, thus increasing the challenges facing anaesthetists.

Blood pressure manipulation during awake carotid surgery to reverse neurological deficit after carotid cross-clamping

We describe the management of three patients undergoing awake carotid surgery who developed signs of cerebral ischaemia after carotid cross-clamping. Drug treatment to increase arterial blood pressure above baseline reversed the neurological deficit and an internal carotid artery shunt was not needed. Shunt insertion is less frequent with regional rather than general anaesthesia, and blood pressure control can reduce this even more. Coincidentally, one of the patients, who gave a history of angina of effort after walking 100 m, complained of chest pain after cross-clamp release. This was treated successfully with sublingual nitroglycerin before ST segment changes became apparent on the ECG. These reports suggest that regional anaesthesia for carotid surgery allows potential complications to be identified earlier than under general anaesthesia using reports from the patient, so that treatment may be modified to prevent morbidity and even mortality.

Patient and hospital benefits of local anaesthesia for carotid endarterectomy

OBJECTIVES

this study reviews and compares carotid endarterectomy (CEA) performed under local anaesthesia (LA) with CEA performed under general anaesthesia (GA) in a single institution.

METHODS

data were collected prospectively from 240 CEA procedures. 140 GA CEA procedures are compared to 100 LA CEA procedures in terms of outcome, operative techniques, complications, and length of stay.

RESULTS

the groups were similar for age, gender distribution and preoperative risk factors. There were more asymptomatic patients in the LA group. There were no significant differences in death, stroke or death/stroke rate between the two techniques. LA CEA was associated with lower shunt rate (LA 13%, GA 50%, p < 0.001), lower incidence of intraoperative hypotension (LA 8%, GA 40%, p < 0.001), decreased hospital stay (median (IQ); LA 2 (1-2), GA 3 (1-4), and a cost saving of pound235 per CEA procedure.

CONCLUSIONS

carotid endarterectomy can be performed safely under local anaesthesia with the advantage that LA CEA enables the surgeon to monitor and selectively shunt patients more accurately. In addition LA CEA is associated with a shorter hospital stay and important cost savings.