Immediate reexploration for the perioperative neurologic event after carotid endarterectomy: is it worthwhile?

Short-term outcomes after selective shunt during carotid endarterectomy: a propensity score matching analysis

INTRODUCTION AND OBJECTIVES

Carotid cross-clamping during carotid endarterectomy might lead to intraoperative neurologic deficits, increasing stroke/death risk. If deficits are detected, carotid shunting has been recommended to reduce the risk of stroke. However, shunting may sustain a specific chance of embolic events and subsequently incurring harm. Current evidence is still questionable regarding its clear benefit. The aim is to determine whether a policy of selective shunt impacts the complication rate following an endarterectomy.

MATERIAL AND METHODS

From January 2013 to May 2021, all patients undergoing carotid endarterectomy under regional anesthesia with intraoperative neurologic alteration were retrieved. Patients submitted to selective shunt were compared to a non-shunt group. A 1:1 propensity score matching (PSM) was performed. Differences between the groups and clinical outcomes were calculated, resorting to univariate analysis.

RESULTS

Ninety-eight patients were selected, from which 23 were operated on using a shunt. After PSM, 22 non-shunt patients were compared to 22 matched shunted patients. Concerning demographics and comorbidities, both groups were comparable to pre and post-PSM, except for chronic heart failure, which was more prevalent in shunted patients (26.1%, P=0.036) in pre-PSM analysis. Regarding 30-day stroke and score Clavien-Dindo ≥2, no significant association was found (P=0.730, P=0.635 and P=0.942, P=0.472, correspondingly, for pre and post-PSM).

CONCLUSIONS

In this cohort, resorting to shunting did not demonstrate an advantage regarding 30-day stroke or a Clavien-Dindo ≥ 2 rates. Nevertheless, additional more extensive studies are mandatory to achieve precise results concerning the accurate utility of carotid shunting in this subset of patients under regional anesthesia.

Neurologic complications of cardiac and vascular surgery

This chapter will provide an overview of the major neurologic complications of common cardiac and vascular surgeries, such as coronary artery bypass grafting and carotid endarterectomy. Neurologic complications after cardiac and vascular surgeries can cause significant morbidity and mortality, which can negate the beneficial effects of the intervention. Some of the complications to be discussed include ischemic and hemorrhagic stroke, seizures, delirium, cognitive dysfunction, cerebral hyperperfusion syndrome, cranial nerve injuries, and peripheral neuropathies. The severity of these complications can range from mild to lethal. The etiology of complications can include a variety of mechanisms, which can differ based on the type of cardiac or vascular surgery that is performed. Our knowledge about neuropathology, prevention, and management of surgical complications is growing and will be discussed in this chapter. It is imperative for clinicians to be familiar with these complications in order to narrow the differential diagnosis, start early management, anticipate the natural history, and improve outcomes.

Immediate Catheter Directed Thrombolysis for Thromboembolic Stroke During Carotid Endarterectomy

Background

Carotid artery endarterectomy (CEA) is a common procedure undertaken by vascular surgeons with over 5,000 procedures performed annually worldwide. Published rates of perioperative stroke range from 1.3% to 6.3%.

Case report

A case is presented in which on-table intra-cranial angiography and catheter directed thrombolysis were used for a thromboembolic occlusion of the distal internal carotid artery (ICA) and proximal middle cerebral artery (MCA). An 83-year-old lady developed a dense right hemiparesis while undergoing a CEA under local anaesthetic (LA). Immediate re-exploration of the endarterectomy did not reveal technical error. Intraoperative duplex scanning of the internal carotid artery revealed no detectable diastolic flow. On-table angiogram showed complete occlusion of the distal ICA and proximal MCA. Catheter directed administration of TPA was undertaken. The entire ICA and MCA were completely clear on a completion angiogram. The patient made a full neurological recovery.

Discussion and conclusion

Prompt diagnosis and treatment with intraoperative catheter directed thrombolysis can resolve thromboembolic occlusion of the ICA/MCA. It is argued that performing CEA under LA is useful for immediate recognition of perioperative stroke. Furthermore, the advantage is highlighted of vascular surgeons having both the resources and skillset to perform on-table angiography and thrombolysis.

•

Post-CEA stroke can be effectively treated with catheter directed thrombolysis.

•

It is important to diagnose and treat distal or intracranial thromboembolism.

•

Rapid stroke recognition during CEA can be aided by performance under local anaesthetic.

•

Vascular surgeons should be able to perform intraoperative angiography and thrombolysis.

Intraoperative sonography during carotid endarterectomy: normal appearance and spectrum of complications

Carotid endarterectomy is a commonly performed procedure for prevention of stroke related to carotid stenosis. Intraoperative sonography is used to identify potentially correctable technical defects during carotid endarterectomy. The main risk of endarterectomy is perioperative stroke, and great effort has been put into trying to reduce this risk through various surgical techniques and evaluation of the surgical bed. Postoperative carotid thrombosis, or thombo-embolization from the arterectomy site, remains a common cause of perioperative stroke and is often related to technical defects in the arterial reconstruction procedure. Re-exploration and repair of any imperfections have the potential to improve outcomes. Intraoperative imaging can identify potentially occult lesions, provide the option for correction, and thus reduce chance of stroke. Familiarity with the spectrum of intraoperative sonographic findings helps correctly identify residual intimal dissection flaps, plaque, thrombi, and stenosis, which may require immediate surgical revision. Our objective is to illustrate the spectrum of intraoperative findings and their importance.

Acute stroke after carotid endarterectomy: time for a paradigm shift? Multicenter experience with emergent carotid artery stenting with or without intracranial tandem occlusion thrombectomy

BACKGROUND

Stroke in the immediate postoperative period after carotid endarterectomy is a rare complication. Many centers have begun incorporating angiography before surgical re-exploration, which has the advantage of confirming carotid occlusion and treating tandem intracranial lesions if present.

OBJECTIVE

To determine the safety and efficacy of this strategy.

METHODS

A retrospective review was performed of all patients undergoing acute stenting of the carotid artery after carotid endarterectomy from November 2009 to June 2013 at 4 centers. Charts and angiographic images were reviewed. Eleven cases of carotid thrombosis within 72 hours of carotid endarterectomy and subsequent treatment strategies are summarized.

RESULTS

All patients had >50% carotid stenosis before carotid endarterectomy. One patient had intraoperative occlusion and dissection of the internal carotid artery, which was noted on intraoperative carotid duplex ultrasound. All patients underwent postoperative computed tomography or computed tomography perfusion scans with subsequent cerebral angiography and stent reconstruction within 11 hours of symptom onset. In all cases, carotid recanalization was successfully completed between 32 and 160 minutes from groin puncture. There were no procedural complications. Four patients had a tandem middle cerebral artery occlusion, 3 of whom underwent successful recanalization.

CONCLUSION

Emergent endovascular evaluation in the setting of acute post--carotid endarterectomy thrombosis is a safe and timely treatment option, with the benefit of detecting and treating embolic intracranial lesions. Immediate angiography and intervention in this rare surgical complication show promising initial results.

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.

Eight-year experience with carotid artery stenting for correction of symptomatic and asymptomatic post-endarterectomy defects

BACKGROUND

Carotid endarterectomy (CEA) has been shown to be superior to medical therapy alone in the prevention of stroke only if it can be safely performed (ie, with a complication rate less than 3% in asymptomatic patients and less than 6% in symptomatic patients). Technical defects are the most common cause of neurological complications after CEA, and their correction has traditionally been performed through standard surgical techniques.

METHODS

From 1999, we started to treat intimal flaps, dissection, or partial thrombosis after CEA with carotid artery stenting (CAS). A retrospective analysis of the operating room registry and of the registry of our Interventional Cardiology laboratory was conducted in order to identify all the patients that underwent stenting of the internal carotid artery after CEA between January 2001 and June 2009.

RESULTS

During the time period considered, 5012 CEA were performed at our institution and a total of 34 patients (34/5012; 0.6%) were found to have received carotid stenting after CEA, both for symptomatic and asymptomatic defects. Immediate technical success was obtained in all patients. One major cerebrovascular adverse event (1/34; 3%) in the immediate perioperative period was recorded. At a mean follow-up of 18.6 months (range, 3-84 months; median, 12 months), we did not observe any neurological symptoms related to the treated carotid artery, nor hemodynamic in-stent restenosis. Long-term follow-up (ie, equal or greater than 4 years) was available for five patients: all patients remained event-free during the entire period.

CONCLUSIONS

Our study adds to the assumption that CAS in post-CEA symptomatic and asymptomatic patients is safe and technically feasible, and represents a valid and quick alternative to standard surgical revision. Even if in a small group of patients, long-term results seem promising.

[Anesthesia for carotid endarterectomy: a review]

Cardiovascular diseases are associated with high rates of morbidity and mortality. Carotid artery stenosis causes between 20% and 25% of ischemic strokes, especially when an embolism is the underlying cause. Carotid endarterectomy is the treatment of choice when stenosis exceeds 60%. It is important to have an understanding of how to manage perioperative factors that can decrease the risk of stroke, infarction, and death. In contrast to the findings of earlier meta-analyses, the recent GALA trial of general versus local anesthesia concluded that the rates of stroke, myocardial infarction, and mortality during or soon after surgery are similar for both types of anesthesia.

Contralateral internal carotid artery occlusion impairs early but not 30-day stroke rate following carotid endarterectomy

Neurological complications and mortality within 30 days following carotid endarterectomy (CEA) alone or with concomitant cardiac surgery/cardiopulmonary bypass (CPB) were assessed in patients with or without contralateral occlusion of the internal carotid artery (CO-ICA).Of 335 patients undergoing CEA, 173 underwent concomitant cardiac surgery with CPB. Group A consisted of 260 patients without CO-ICA and group B of 75 patients with CO-ICA. The neurological complications (peripheral nerve damage, transient ischemic attack [TIA], prolonged reversible ischemic neurological deficit [PRIND], and stroke) and the Rankin index within 24 hours and 30 days postoperatively were compared. Strokes within 24 hours were significantly increased (P = .006) in group B (11%) compared with A (3.1%); TIA and PRIND did not differ (P = .33). The overall neurological complications and in particular for peripheral neurological damage, TIA/PRIND, and stroke did not differ within the 30-day-period postsurgery. A significantly higher stroke rate within 24 hours postsurgery occurred in patients with CO-ICA.

Early acute hemispheric stroke after carotid endarterectomy. Pathogenesis and management

PURPOSE

A major stroke after carotid endareterectomy (CEA) is an event that should be managed according to a planned strategy. Literature data on this issue are not definitive. We reviewed our series in the attempt to define an algorithm of treatment if this complication occurs.

METHODS

A consecutive series of 413 CEAs in 390 patients was considered. All operations were performed under general anaesthesia and EEG monitoring. An indwelling shunt was inserted only according to EEG changes. Direct closure of the arteriotomy was performed in all cases. Intraoperative ultrasound was not routinely employed before 2004. Patients who suffered from the new onset of an ischaemic hemispheric deficit or the worsening of a pre-existing deficit within 72 h after surgery were included in the present study.

RESULTS

Sixteen patients (3.9%) suffered from perioperative stroke. Seven patients presented neurological deficits that rapidly and spontaneously resolved. In nine cases (2.2%) a major stroke occurred. Acute occlusion of the internal carotid artery (ICA), with or without embolic blocking of the omolateral M1 segment, occurred in eight cases; in one case a patent ICA was associated with the occlusion of two frontal branches of the omolateral middle cerebral artery. Seven cases were reoperated on. The ICA was reopened in all these cases except one. Among these seven cases, three (42%) had a good outcome.

CONCLUSIONS

A major stroke after CEA is caused, in most of cases, by the acute ICA occlusion with or without intracerebral embolic occlusion. Reopening of the occluded ICA gives good results when intracerebral vessels are patent and when the occluded ICA is satisfactorily reopened. An algorithm of planned reactions in case of perioperative stroke is finally proposed.

Wake-Up Test After Carotid Endarterectomy for Combined Carotid–Coronary Artery Surgery: A Case Series

OBJECTIVE

In combined carotid-coronary artery surgery, it is important to determine patients' neurologic status after carotid endarterectomy (CEA). An initial stroke could be exacerbated by cardiopulmonary bypass required for coronary artery bypass graft (CABG) surgery. Various monitoring methods (eg, electroencephalogram) have been used to reduce neurologic deficits during CEA under general anesthesia. However, none of the methods of determining neurologic status of patients are ideal during the time between the end of CEA and the beginning of CABG surgery. In this study, patient's neurologic status was assessed after CEA with a wake-up test to identify stroke before CABG surgery.

DESIGN

A prospective nonrandomized case series.

SETTING

Single institution, university hospital.

PARTICIPANTS

Forty-four patients with carotid artery stenosis and coronary artery disease underwent combined carotid-coronary artery surgery.

INTERVENTIONS

After CEA, propofol and remifentanil anesthesia was discontinued, the wake-up test was performed, and then anesthesia was reinstituted for CABG surgery.

MEASUREMENTS AND RESULTS

A total of 48 wake-up tests were performed in 43 patients. Two wake-up tests were performed in each of the 5 patients who underwent bilateral CEA. Postoperative stroke were seen in 2 patients. In the first patient, despite a normal wake-up test, the stroke occurred in the cerebral hemisphere contralateral to the CEA, and the patient recovered within 12 days. In the second patient, there was a positive wake-up test after CEA, and he recovered within 3 days. One patient died postoperatively because of ventricular failure.

CONCLUSIONS

Although this is a case series, the authors believe that performing a neurologic examination using a wake-up test may make a contribution and increases the safety of combined surgical procedures in patients with coronary and carotid artery disease.

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.

A personal experience with coronary artery bypass grafting, carotid patching, and other factors influencing the outcome of carotid endarterectomy

OBJECTIVE

This study was conducted to investigate the influence of coronary artery bypass grafting (CABG), carotid patching, and other factors on the outcome of all carotid endarterectomies (CEAs) performed by a single surgeon at a tertiary referral center.

METHODS

The series includes 2262 CEAs (335 bilateral) in 1521 men and 741 women (33%) with median ages of 66 and 68 years, respectively. Surgical indications were asymptomatic stenosis for 1503 procedures (66%), retinal ischemia or cerebral transient ischemic attacks each for 271 (12%), and prior stroke for 217 (9.6%). CEA was done as an isolated operation in 1959 patients and was performed in conjunction with simultaneous CABG in 303 (13%). Primary arteriotomy closure was used for 783 CEAs (35%), vein patching for 1232 (54%), and synthetic patching for 247 (11%). Outcome event rates were assessed by logistic regression analysis, proportional hazards models, and Kaplan-Meier estimations.

RESULTS

Postoperative mortality (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.7 to 7.5; P = .001), stroke (OR, 3.2; 95% CI, 1.6 to 6.4; P = .001), and combined stroke and mortality rates (OR, 3.4; 95% CI, 2.0 to 5.8; P < .001) were significantly higher for simultaneous CEA/CABG than for isolated CEA. Ipsilateral postoperative stroke rates were similar (2.6% vs 1.7%, P = .41) in both settings. Vein patching had a lower risk for ipsilateral stroke (OR, 0.42; 95% CI, 0.21 to 0.86; P = .015) than primary closure, but was not significantly different from synthetic patching (P = .10). The documented incidence of postoperative carotid thrombosis was 1.5% with primary closure, 0.6% with vein patching, and 2.0% with synthetic patching (P = .088). Overall Kaplan-Meier survival was 92% at 1 year, 71% at 5 years, 41% at 10 years, and 20% at 15 years, but long-term mortality rates were higher after simultaneous CEA/CABG (hazard ratio, 1.3; 95% CI, 1.1 to 1.5; P = .002) than after CEA alone. Late strokes or retinal infarctions have been reported after 97 (5.0%) of the 1923 operations for which follow-up was available, 51 (2.3%) of which were ipsilateral to CEA. The incidence of > or = 60% recurrent stenosis was independently influenced by carotid patching (OR, 0.61; 95% CI, 0.40 to 0.92; P = .019) but not by the choice of patch material (P = .11).

CONCLUSIONS

These results substantiate the common observation that patients who require simultaneous CEA/CABG have a higher risk for adverse outcomes than patients who undergo isolated CEA. Carotid patching provided significant benefit with respect to the risks for ipsilateral postoperative stroke and > or = 60% recurrent stenosis.

Intravenously Administered Abciximab in the Management of Early Cerebral Ischemia after Carotid Endarterectomy: Case Report

OBJECTIVE AND IMPORTANCE:

Cerebral ischemia is the most worrisome perioperative complication of carotid endarterectomy (CEA). The stroke rate occurring with CEA is estimated to range from 2.3 to 6.3%. Numerous treatment options are available to the neurosurgeon in this scenario, although no “gold standard” exists.

CLINICAL PRESENTATION:

A 61-year-old woman presented with acute left arm weakness 40 minutes after an uneventful CEA for symptomatic carotid stenosis. Emergent angiography demonstrated vascular irregularities in a “moth-eaten” pattern along the arteriotomy closure, suggestive of platelet-fibrin aggregates (“white clot”).

INTERVENTION:

Abciximab was immediately administered intravenously in the angiography suite, with subsequent improvement of the visualized vascular irregularities on a second angiogram performed 12 minutes after infusion and complete resolution of the presumed platelet-fibrin aggregates on a third angiogram performed the next day. The patient had no further episodes of cerebral ischemia. She was discharged home on the fifth postoperative day with improving left arm weakness, which had completely resolved by her 2-month follow-up visit.

CONCLUSION:

To our knowledge, this is the first reported case of abciximab administered intravenously in the setting of acute thromboembolic brain ischemia after CEA. For the unique situation in which an acute thrombus, or white clot, is thought to be the cause of cerebral ischemia, we believe that abciximab may offer an effective and potentially safer alternative than fibrinolytics and may be a more appropriate drug to use from a physiological perspective.

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.

Intraoperative carotid artery duplex scanning in a modern series of 650 consecutive primary endarterectomy procedures

PURPOSE

Thromboembolic complications after carotid endarterectomy are frequently associated with technical defects. We analyzed the effect of intraoperative duplex scanning in detection of significant but clinically unsuspected technical defects and residual common carotid artery (CCA) disease as a potential source of postoperative transitory ischemic attack (TIA) and stroke.

METHODS

From April 2000 to April 2003, 650 consecutive primary carotid endarterectomy procedures were performed in 590 patients at a single institution by two vascular surgeons. Patients included 335 men (57%) and 255 women (43%). Indications for surgery were asymptomatic internal carotid artery (ICA) stenosis (>or=70%) in 464 patients (71%). All procedures were performed with the patient under general anesthesia, with synthetic patch angioplasty in 644 (99.1%). Major technical defects at intraoperative duplex scanning (>30% luminal internal carotid artery stenosis, free-floating clot, dissection, arterial disruption with pseudoaneurysm) were repaired. CCA residual disease was reported as wall thickness (0.7-4.8 mm; mean, 1.7 +/- 0.7) and percent stenosis (16%-67%; mean, 32% +/- 8%) in all cases. Postoperative 30-day TIA, stroke, and death rates were analyzed.

RESULTS

There were no clinically detectable postoperative thromboembolic events in this series. All 15 major defects (2.3%) identified with duplex scanning were successfully revised. These included 7 intimal flaps, 4 free-floating clots, 2 ICA stenoses, 1 ICA pseudoaneurysm, and 1 retrograde CCA dissection. Diameter reduction ranged from 40% to 90% (mean, 67 +/- 16%), and peak systolic velocity ranged from 69 to 497 cm/s (mean, 250 +/- 121 cm/s). Thirty-one patients (5%) with the highest residual wall thickness (>3mm) in the CCA and 19 (3%) with the highest CCA residual diameter reduction (>50%) did not have postoperative stroke or TIA. Overall postoperative stroke and mortality rates were 0.3% and 0.5%, respectively; combined stroke and mortality rate was 0.8%. One stroke was caused by hyperperfusion, and the other occurred as an extension of a previous cerebral infarct. No patients had TIAs. Two deaths were caused by myocardial infarction, and one death by respiratory insufficiency.

CONCLUSION

We believe intraoperative duplex scanning had a major role in these improved results, because it enabled detection of clinically unsuspected significant lesions. Residual disease in the CCA does not seem to be a harbinger of stroke or TIA.

Reoperation for neurological complications following carotid endarterectomy

BACKGROUND

There remains a dilemma whether or not to re-explore the carotid artery when a neurological complication occurs after carotid endarterectomy. This study reviewed the indications for, findings and clinical outcomes following re-exploration.

METHODS

Patients who experienced transient or permanent neurological events following carotid endarterectomy were identified from a prospectively compiled computerized database. Case notes were retrieved to determine time to onset of symptoms, use of carotid artery imaging and details about patients who had surgical re-exploration, and outcomes.

RESULTS

Some 780 consecutive carotid endarterectomies were performed over 16 years, with an incidence of major stroke or death of 2.3 per cent (18 patients). Fifty-one patients experienced transient or permanent neurological events following surgery, 25 of whom underwent re-exploration. The findings included carotid thrombosis (ten patients), flap or other technical cause (three), haematoma (two) and no abnormality (ten). The neurological outcome after 30 days was similar, whether or not the carotid artery was re-explored.

CONCLUSION

Carotid artery re-exploration was undertaken in approximately half of the patients who developed neurological complications following carotid endarterectomy. Although the cause was identified and a secondary procedure was undertaken in 14 of 25 patients, there was no improvement in clinical outcome at 30 days compared with that of patients managed non-operatively.

Cerebral hyperperfusion syndrome after carotid endarterectomy: predictive factors and hemodynamic changes

PURPOSE

It is believed that cerebral hyperperfusion syndrome (CHS) is caused by loss of cerebral autoregulation resulting from chronic cerebral ischemia and that factors including increased intraoperative cerebral blood flow, ipsilateral or contralateral carotid disease, and postoperative hypertension may cause CHS. We describe our experience with CHS, which diverges from published reports.

MATERIALS AND METHODS

From March 2000 to February 2002 we performed 455 carotid endarterectomy (CEA) procedures in 404 patients at our institution. CHS developed 1 to 8 days (mean, 3.2 +/- 2.5 days) postoperatively in 9 patients (2%), 6 women and 3 men, whose age ranged from 52 to 84 years (mean, 69 +/- 8 years). Indications for surgery in 8 patients without neurologic symptoms were ipsilateral internal carotid artery (ICA) stenoses ranging from 70% to 99% (mean, 80% +/- 7%); the remaining patient had an ipsilateral stroke, with good clinical recovery, 7 weeks before CEA. Only 1 patient had significant contralateral ICA stenosis (70%). However, 5 patients had undergone contralateral CEA within the previous 3 months. CHS symptoms were severe headache in 5 patients, seizures in 3 patients (1 stroke), and visual disturbance and ataxia in 1 patient. All 404 patients (455 cases) underwent intraoperative and early (2 weeks) postoperative carotid artery duplex scanning. The 9 patients with CHS also underwent carotid artery duplex scanning at the time of the neurologic event.

RESULTS

Mean intraoperative ICA volume flow (MICAVF) in the 9 CHS cases was not significantly different from that in the other 446 cases (170 +/- 47 mL/min and 182 +/- 81 mL/min, respectively). However, mean ICA volume flow (481 +/- 106 mL/min) and peak systolic velocity (PSV) (108 +/- 33 cm/s) for the 9 CHS cases measured at onset of symptoms were higher than those for the remaining 446 cases (267 +/- 87 mL/min and 80 +/- 26 cm/s, respectively) (P <.01). Of the 9 patients with CHS, only 3 had systolic blood pressures more than 160 mm Hg at onset of symptoms. Severity of ipsilateral and contralateral ICA stenoses was not significantly different between the 9 CHS cases and the remaining 446 cases.

CONCLUSIONS

These data do not corroborate the common belief that CHS occurs preferentially in patients with severe ipsilateral or contralateral carotid disease, increased intraoperative cerebral perfusion, or severe hypertension. Recently performed contralateral CEA (<3 months) appears to be predictive of CHS.

Reoperation for acute hemispheric stroke after carotid endarterectomy: is there any value?

OBJECTIVE

Because the clinical benefit of urgent investigation and carotid re-repair for acute stroke complicating carotid endarterectomy (CEA) is uncertain, the results of this approach were examined in a large series of patients.

METHODS

In a consecutive series of 700 CEAs, 24 patients (3.4%) had a postoperative stroke. Thirteen of these 24 patients experienced major hemispheric deficits (hemiplegia with or without aphasia, forced eye deviation, and decreased consciousness) that prompted either immediate surgical reexploration or cerebral angiography with reoperation on the basis of angiogram results; these 13 patients are the subject of this report. Neurological improvement was attributed to carotid reopening when affected muscle strength increased to antigravity power within 6 hours of reoperation.

RESULTS

Of the 13 patients with severe postoperative deficits, 5 (38%) had the deficits when they awakened, 7 deficits occurred within 12 hours of surgery, and the only intracerebral hemorrhage in this series occurred 8 days after surgery. Five patients underwent urgent reoperation without angiography, and carotid occlusions were found and repaired in two patients. In another patient, the carotid was patent, and an intra-arterial injection of tissue plasminogen activator (20 mg) was given. In the seven patients who underwent cerebral angiography as the first step, two carotid occlusions and one residual stenosis with thrombus were found and repaired on an urgent basis. Surgical reopening of occluded arteries was followed by improvement in two of four patients, and early improvement was noted in one patient with a stenosis correction as well as in the patient who received intraoperative tissue plasminogen activator. Four patients who underwent urgent reoperation did not demonstrate a benefit soon after surgery. Two patients died, two were left with major deficits and five with moderate deficits, and four patients eventually had good recovery at a minimum of 6 months of follow-up.

CONCLUSION

In this series, approximately one-half of hemispheric strokes complicating CEA had an underlying correctable lesion (occlusion or stenosis), and these patients typically had delayed-onset strokes. Approximately one-half of these patients improved early as a result of reopening, although computed tomography revealed new infarcts in most of them. Urgent carotid repair may benefit a minority of selected patients who have a major stroke after CEA.

Internal carotid artery flow volume measurement and other intraoperative duplex scanning parameters as predictors of stroke after carotid endarterectomy

PURPOSE

Intraoperative duplex scanning (IDS) after carotid endarterectomy (CEA) has been shown to reliably identify major defects either by significant changes in peak systolic velocities or by B-mode imaging. To evaluate whether IDS could also predict postoperative strokes in technically flawless CEAs, we analyzed several hemodynamic parameters and correlated them with patient outcome.

METHODS

From March 2000 to February 2001, 226 consecutive primary CEAs were performed in 208 patients (120 men). Of these, 153 lesions were asymptomatic. General anesthesia and synthetic carotid artery patches were used routinely. Intraluminal shunts were used when internal carotid artery (ICA) back-pressures were <50 mm Hg (35% of cases). IDS consisted of B-mode and color-flow imaging and spectral analyses of the common, external, and internal carotid arteries. Volume flows were measured three times, and the mean flow rate was used for this study.

RESULTS

The first set of data was analyzed when the twenty-ninth patient had the second immediate postoperative stroke. It was noted that the two patients who had postoperative strokes had mean ICA volume flows (MICAVF) of 48 mL/min and 85 mL/min. Only two additional patients had MICAVF <100 mL/min. The remaining 25 cases had MICAVF ranging from 102 to 299 mL/min, with a mean of 165 +/- 57 mL/min (+/-SD) (P <.02). Although there was a significant correlation between MICAVF and ICA peak systolic velocity (P <.01), the latter was not found to be a significant predictor of postoperative stroke. Moreover, end-diastolic velocities, resistive index, ICA diameter, and ICA back-pressure also did not correlate with neurologic events. These findings led us to change our protocol for patients with MICAVF <100 mL/min. This included a repeat set of volume flow measurements after 15 to 20 minutes, withholding the reversal of heparin, and the liberal use of completion arteriography. Of the following 197 CEAs, 26 (13%) were found to have MICAVF <100 mL/min (range 55 to 99 mL/min; mean 79 +/- 18 mL/min). Of these, five had arteriography that documented spasm of the intracranial portion of the ICA in four and a small-diameter ICA (<2 mm) in one. Except for the five cases, the remaining 21 cases had MICAVF >100 mL/min (range 105 to 158 mL/min, mean 127 +/- 20 mL/min [+/-SD]) on repeat study. Four patients with persistent ICA low flow (70 to 99 mL/min) were treated with postoperative anticoagulation. One of the last 197 patients had a stroke caused by hyperperfusion syndrome 2 weeks after operation. Overall, six of 226 cases (2.7%) required revision on the basis of abnormal B-mode imaging results or peak systolic velocities >150 cm/s. There were two common carotid artery flaps, two ICA stenoses, one ICA flap, and one localized thrombus. All six were successfully revised and had repeat normal IDS study results, and none of these patients had a postoperative stroke.

CONCLUSIONS

IDS is helpful in identifying residual lesions or defects that may contribute to postoperative neurologic deficits. MICAVF <100 mL/min are suggestive of spasm that could lead to thrombus formation and stroke, particularly in the presence of synthetic patches. We suggest that heparin reversal should not be used unless ICA flow rates are >100 mL/min. ICA spasm is short lived in most patients undergoing CEA.

Remifentanil conscious sedation during regional anaesthesia for carotid endarterectomy: rationale and safety

OBJECTIVES

to prospectively evaluate the safety and efficacy of remifentanil during regional anaesthesia for carotid endarterectomy.

METHODS

twenty-eight consecutive patients underwent carotid endarterectomy with combined superficial and deep cervical plexus block supplemented with continuous intravenous 0.04 microg.kg(-1).min(-1)remifentanil infusion. Depth of sedation was monitored using the Observer's Assessment of Alertness/Sedation Scale (OAA/S). The degree of pain, discomfort and anxiety was self-assessed by the patients using a horizontal visual analogue scale.

RESULTS

all patients experienced adequate comfort and analgesia. No local anaesthetic supplementation was necessary. No patient had a OAA/S score lower than 4 (with 5=awake/alert to 1=asleep). Respiratory depression did not occur. Selective shunting was required in four cases. No patient was converted to general anaesthesia. There were no permanent neurological deficits, cardiopulmonary complications or deaths.

CONCLUSION

remifentanil as a supplement to regional anaesthesia for carotid endarterectomy, provides comfort and analgesia without hampering mental status evaluation.