Immediate reoperation for perioperative stroke after 2250 carotid endarterectomies: differences between intraoperative and early postoperative stroke

Diagnosis and management of acute conditions of the extracranial carotid artery

Symptomatic carotid stenosis and carotid dissection are acute conditions of extracranial cerebrovascular vessels determining transient ischemic attack or stroke. Medical, surgical, or endovascular management are different options to treat these pathologies. This narrative review focused on the management, from symptoms to treatment, of the acute conditions of extracranial cerebrovascular vessels, including post-carotid revascularization stroke. Symptomatic carotid stenosis (> 50% according to North American Symptomatic Carotid Endarterectomy Trial criteria) with transient ischemic attack or stroke benefits from carotid revascularization-primarily with carotid endarterectomy associated with medical therapy-within 2 weeks from symptom onset to reduce the risk of stroke recurrence. Different from acute extracranial carotid dissection, medical management with antiplatelet or anticoagulant therapy can prevent new neurologic ischemic events, considering stenting only in case of symptom recurrence. Stroke after carotid revascularization can be associated with the following etiologies: carotid manipulation, plaque fragmentation, or clamping ischemia. Medical or surgical management is therefore influenced by the cause and timing of the neurologic events after carotid revascularization. Acute conditions of the extracranial cerebrovascular vessels include a heterogeneous group of pathologies and correct management can reduce symptom recurrence substantially.

Procedural Stroke after Carotid Revascularization - Critical Analysis of the Literature and Standards of Reporting

OBJECTIVE

Mechanisms of procedural stroke after carotid endarterectomy (CEA) or stenting (CAS) are surprisingly underresearched. However, understanding the underlying mechanism could: (1) assist in balancing the choice for revascularization versus conservative therapy; (2) assist in choosing either open or endo techniques; and (3) assist in taking appropriate periprocedural measures to further reduce procedural stroke rate. The purpose of this study was to overview mechanisms of procedural stroke after carotid revascularization and establish reporting standards to facilitate more granular investigation and individual patient data meta-analysis in the future.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) statement.

RESULTS

The limited evidence in literature was heterogeneous and of low quality and hence no formal data meta-analysis could be performed. Procedural stroke was classified as haemorrhagic or ischemic; the latter was subclassified as haemodynamic, embolic (carotid- or cardio-embolic) or carotid occlusion-derived, using a combination of clinical inference and imaging data. Most events occurred in the first 24h after the procedure and were related to hypoperfusion (pooled incidence 10.2% (95% c.i. 3.0-17.5) versus 13.9% (95% c.i. 0.0-60.9) post-CEA vs CAS events, respectively) or atheroembolism (28.9% (95% c.i. 10.9-47.0) versus 34.3 (95% c.i. 0.0-91.5)) After the first 24 hours, haemorrhagic stroke (11.6 (95% c.i. 5.7-17.4) versus 9.0 (95% c.i. 1.3-16.7)) or thrombotic occlusion (18.4 (95% c.i. 0.9-35.8) versus 14.8 (95% c.i. 0.0-30.5)) became more likely.

CONCLUSIONS

Although procedural stroke incidence and aetiology may have changed over the last decades due to technical improvements and improvement in perioperative monitoring and quality control, the lack of literature data limits further statements. To simplify and enhance future reporting, procedural stroke analysis and classification should be documented pre-emptively in research settings. We propose a standardized form enclosing reporting standards for procedural stroke with a systematic approach to inference of the most likely aetiology, for prospective use in registries and RCTs on carotid revascularization.

Computed tomography perfusion abnormalities after carotid endarterectomy help in the diagnosis of reversible cerebral vasoconstriction syndrome

Acute neurologic deficits in the postoperative period after carotid endarterectomy (CEA) can prompt extensive diagnostic evaluation. Reversible cerebral vasoconstriction syndrome (RCVS) is an underrecognized cause of acute neurologic deficit after CEA. We present the case of RCVS in an 84-year-old male patient who had experienced left limb weakness after CEA, prompting multiple code stroke activations. The present case is novel because the obtained computed tomography perfusion imaging studies demonstrated abnormalities that have not been previously described in patients with RCVS. These findings, combined with the cerebral angiography findings, led to the rapid diagnosis and delivery of intra-arterial vasodilator therapy. He experienced subsequent resolution of his symptoms and radiologic abnormalities.

Mechanism of Procedural Stroke Following Carotid Endarterectomy or Carotid Artery Stenting Within the International Carotid Stenting Study (ICSS) Randomised Trial

OBJECTIVE

To decrease the procedural risk of carotid revascularisation it is crucial to understand the mechanisms of procedural stroke. This study analysed the features of procedural strokes associated with carotid artery stenting (CAS) and carotid endarterectomy (CEA) within the International Carotid Stenting Study (ICSS) to identify the underlying pathophysiological mechanism.

MATERIALS AND METHODS

Patients with recently symptomatic carotid stenosis (1,713) were randomly allocated to CAS or CEA. Procedural strokes were classified by type (ischaemic or haemorrhagic), time of onset (intraprocedural or after the procedure), side (ipsilateral or contralateral), severity (disabling or non-disabling), and patency of the treated artery. Only patients in whom the allocated treatment was initiated were included. The most likely pathophysiological mechanism was determined using the following classification system: (1) carotid-embolic, (2) haemodynamic, (3) thrombosis or occlusion of the revascularised carotid artery, (4) hyperperfusion, (5) cardio-embolic, (6) multiple, and (7) undetermined.

RESULTS

Procedural stroke occurred within 30 days of revascularisation in 85 patients (CAS 58 out of 791 and CEA 27 out of 819). Strokes were predominately ischaemic (77; 56 CAS and 21 CEA), after the procedure (57; 37 CAS and 20 CEA), ipsilateral to the treated artery (77; 52 CAS and 25 CEA), and non-disabling (47; 36 CAS and 11 CEA). Mechanisms of stroke were carotid-embolic (14; 10 CAS and 4 CEA), haemodynamic (20; 15 CAS and 5 CEA), thrombosis or occlusion of the carotid artery (15; 11 CAS and 4 CEA), hyperperfusion (9; 3 CAS and 6 CEA), cardio-embolic (5; 2 CAS and 3 CEA) and multiple causes (3; 3 CAS). In 19 patients (14 CAS and 5 CEA) the cause of stroke remained undetermined.

CONCLUSION

Although the mechanism of procedural stroke in both CAS and CEA is diverse, haemodynamic disturbance is an important mechanism. Careful attention to blood pressure control could lower the incidence of procedural stroke.

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.

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.

Intracranial Aneurysms in Patients With Carotid Disease

Before the routine use of computed tomography (CT) angiography, decisions for carotid artery treatment were mostly based on ultrasound findings and conventional angiography. Implementation and increasing use of CT angiography provided better visualization of the carotid and vertebrobasilar arteries system leading to an unexpected more frequent detection of unruptured intracranial aneurysms (UIAs). Concomitant presence of intracranial aneurysms in patients with severe carotid stenosis is a potential cause of significant mortality and morbidity. Due to the possible higher risk of aneurysm rupture after carotid procedures and ischemic events after aneurysm repair, the simultaneous presence of both lesions creates several therapeutic dilemmas. We review the prevalence of UIAs in patients with carotid occlusive disease and management difficulties and the current treatment strategies for handling the concomitant presence of these life-threatening diseases.

Carotid endarterectomy should be performed early after a cerebral ischemic event in order to be most effective

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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.

Low molecular weight heparin significantly reduces embolisation after carotid endarterectomy--a randomised controlled trial

OBJECTIVES

The administration of unfractionated heparin (UFH) prior to carotid clamping during carotid endarterectomy (CEA) transiently increases the platelet aggregation response to arachidonic acid (AA) despite the use of aspirin. We hypothesized that this phenomenon might be reduced by using low molecular weight heparin (LMWH) resulting in fewer emboli in the early post-operative period.

METHODS

183 aspirinated patients undergoing CEA were randomised to 5000 IU UFH (n=91) or 2500 IU LMWH (dalteparin, n=92) prior to carotid clamping. End-points were: transcranial Doppler (TCD) measurement of embolisation, effect on bleeding and platelet aggregation to AA and adenosine 5'-diphosphate (ADP).

RESULTS

Patients randomised to UFH had twice the odds of experiencing a higher number of emboli in the first 3h after CEA, than those randomised to LMWH (p=0.04). This was not associated with increased bleeding (mean time from flow restoration to operation end: 23 min (UFH) vs. 24 min (LMWH), p=0.18). Platelet aggregation to AA increased significantly following heparinisation, but was unaffected by heparin type (p=0.90). The platelets of patients randomised to LMWH exhibited significantly lower aggregation to ADP compared to UFH (p<0.0001).

CONCLUSIONS

Intravenous LMWH is associated with a significant reduction in post-operative embolisation without increased bleeding. The higher rate of embolisation seen with UFH may be mediated by increased platelet aggregation to ADP, rather than to AA.

[Styloid syndrome: a review of literature]

The American otolaryngologist Eagle was the first to describe styloid syndrome in 1937. Stylohyoid complex is composed of styloid process, stylohyoid ligament and a lesser horn of the hyoid bone. Embriologicaly, these anatomical structures originate from Reichert's cartilage of the second brachial arch. In the general population, the frequency of the elongated styloid process is estimated to be 4%, of which only 4% show clinical manifestations suggesting that the incidence of styloid syndrome is 0.16% (about 16,000 persons in Serbia). The styloid process deviation causes external or internal carotid impingement and pains which radiate along the arterial trunk. Classical stylohyoid syndrome is found after tonsillectomy and is characterised by pharyngeal, cervical, facial pain and headache. Stylo-carotid syndrome is the consequence of the pericarotid sympathetic fibres irritation and compression on the carotid artery. Clinical manifestations are found most frequently after head turning and neck compression. The diagnostic golden standard for styloid syndrome is 3D CT reconstruction. Sagital CT angiography has a leading role in the radiological diagnosis of the stylo-carotid syndrome. Differential diagnosis requires the differentiation of the styloid syndrome from numerous cranio-facio-cervical painful syndromes. If conservative treatment (analgesics, anticonvulsants, antidepressants, and local infiltration with steroids or anaesthetic agents) has no effect, surgical treatment is applied. Styloid syndrome is underrepresented in neurological literature. The syndrome is considered important, because it is clinically similar to many other painful cranio-facial syndromes; it is difficult to be recognized, and the patient should be treated adequately.

[Why carotid endarterectomy is method of choice in treatment of carotid stenosis]

Procedures used in treatment of carotid stenosis are endarterectomy, PTA with stent implantation, resection with graft interposition and by-pass procedure. Segmental lesions are found more often and treated by the first two mentioned procedures. In case of longer lesions and extension to the greater part of the common carotid artery, the other two procedures are performed. For the past few years, the main dilemma has been whether to perform carotid endarterectomy or PTA with stent implantation. Both early and long-term results speak in favour of carotid endarterectomy, regardless of an increased number of PTA and carotid stenting. At the same time, PTA and carotid stenting are more expensive procedures. Both methods have their defined and important roles in treatment of segmental occlusive carotid lesions. Severe cardiac, pulmonary and renal conditions, which increase the risk of general anaesthesia, are not an absolute indication for PTA and stenting, since endarterectomy can be done in regional anaesthesia. Main indications for PTA with stent implantation are: surgically inaccessible lesions (at or above C2; or subclavian); radiation-induced carotid stenosis; prior ipsilateral radical neck dissection; prior carotid endarterectomy (restenosis).

Hemodynamic cerebral ischemia during carotid endarterectomy evaluated by intraoperative monitoring and post-operative diffusion-weighted imaging

OBJECTIVE

We used the result of monitoring to evaluate patients with post-operative neurological deficits attributable to hemodynamic cerebral ischemia owing to cross-clamping of the carotid artery.

METHODS

We evaluated 131 carotid endarterectomy (CEA) procedures performed on 118 patients, 96 men and 22 women ranging in age from 38 to 82 years (mean: 67.1 years). For monitoring, we used a combination of somatosensory evoked potential (SEP), functional dynamic electroencephalography (EEG), near-infrared spectroscopy (NIRS) and transcranial Doppler (TCD). Patients who awoke with neurological deficits after CEA immediately underwent diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA).

RESULTS

In 30 of the 131 procedures (22.9%), intraoperative monitoring disclosed abnormalities after cross-clamping of the internal carotid artery (ICA). In two of these 30 patients, shunt was not introduced, because of full recovery of monitoring after blood pressure increasing, however, one patient demonstrated transient ischemic attack (TIA). In six of remaining 28 patients who need shunt, transient hemodynamic cerebral ischemia occurred, however, all patients recovered gradually within 18 hours after CEA. No new lesions were detected on post-operative DWI of the seven patients and MRA demonstrated good patency of the carotid artery. The other 101 patients whose intraoperative monitoring after cross-clamping of the ICA did not disclose abnormalities demonstrated no hemodynamic TIA.

CONCLUSION

Hemodynamic ischemia owing to cross-clamping of the ICA is rare in patients treated by CEA. However, in patients manifesting neurological deficits upon awakening from CEA, DWI and MRA should be performed immediately to facilitate their prompt treatment.

The evolution of extracranial carotid artery surgery as seen by one surgeon over the past 40 years

Carotid endarterectomy is one of the most common vascular and neurosurgical operations. Controversies regarding its indications and safety have required several decades before general resolution, while its methodology is still debated. The first operations are described with particular emphasis on the epic successful procedure in 1954 by Eastcott and Rob. Early procedures were on patients with frank strokes with poor results. The development of carotid endarterectomy was slow because neurologists were unsure of its effectiveness and safety as the mortality and stroke results recorded by untrained surgeons were unacceptable. It was not until some 35 years after its introduction that randomised controlled trials, both in North America and Europe, defined its indications and demonstrated its benefits for both symptomatic and asymptomatic carotid stenosis. Clamping of the carotid vessels, required during endarterectomy, may result in various degrees of cerebral ischaemia. Methods to determine which patients need shunting are compared. The author has employed local neck block anesthesia since 1972, which is the only method that provides constant neurological assessment for selective shunting during carotid cross clamping. Evidence is presented showing that local anaesthesia also reduces complications of general anaesthesia, especially myocardial infarction. The technique of neck block, conventional endarterectomy and two varieties of eversion endarterectomy for carotid disease are described. Each of these techniques of endarterectomy is advantageous in certain circumstances, suggesting that vascular surgeons should ideally be proficient in each. Likewise, the management of early stroke after operation, stenotic or occluded external carotid the presence of retinal Hollenhorst plaques, and the totally occluded internal carotid, is presented. Finally, observations on some famous figures who suffered from cerebrovascular complications secondary to carotid disease and what effect it may have had on world history is discussed.

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.

EEG as a criterion for shunt need in carotid endarterectomy

The efficacy of continuous intraoperative electroencephalographic (EEG) monitoring as a criterion for selective shunt use during carotid endarterectomy is evaluated in a group of 1661 operations in which the EEG was the sole criterion for shunt insertion. EEG monitoring is measured by the intraoperative stroke rate. Carotid stump pressure measurements were recorded as an additional observation in 1517 operations and represent a subset of the study group allowing comparison of this technique with EEG. Intraoperative stroke rate for the 1661 operations in the study group was 0.03% (five strokes). A statistically significant increase in intraoperative stroke rate was associated with the development of an abnormal EEG (1.1%), contralateral internal carotid artery occlusion (1.8%), and the combination of both abnormal EEG and contralateral internal carotid occlusion (3.3%). The EEG remained normal in 1295 operations including 75 operations with contralateral internal carotid artery occlusion. One minor intraoperative stroke (0.08%) which resolved in 1 week occurred in the absence of an EEG change with no intraoperative strokes in the 75 operations in which the contralateral internal carotid artery was occluded. Intraoperative EEG monitoring accurately (99.92%) identified patients who may safely have carotid endarterectomy without the need of a shunt.

The effect of intraoperative duplex on the management of postoperative stroke

BACKGROUND

Stroke after carotid endarterectomy (CEA) may be a result of intraoperative ischemia, embolism, or thrombosis at the operative site. Intraoperative duplex should eliminate the occurrence of a severe internal carotid artery (ICA) thrombosis and, thus, negate the benefit of reoperation. This article will detail the results of our evolving treatment algorithm for immediate versus delayed post-CEA neurologic deficit (ND).

METHODS

We studied patients who had an ND after CEA from 1988 to 2000. Results. Thirty-two patients (3.2%) had a post-CEA ND (26 related stroke or transient ischemic attack, 6 other); 31 had a satisfactory intraoperative duplex post-CEA, 1 was not tested. Fifteen patients awoke from operation with a related deficit, 5 of whom were re-explored and all had a patent ICA. One patient without lateralizing signs who was not re-explored had extensive thrombosis at postmortem. The remaining 9 all had a duplex-proven patent ICA. Ten patients had a lucid interval before their related ND. Six patients were re-explored and all had thrombosed ICAs; 5 of the 6 improved postthrombectomy. Four patients were not re-explored for various reasons; a carotid thrombosis was not later diagnosed in any of these patients.

CONCLUSIONS

Intraoperative and postoperative duplex has modified our treatment of post-CEA stroke. No longer are all patients re-explored. Patients with a normal intraoperative duplex who awaken with an immediate stroke do not usually have occlusive thrombus and routine re-exploration does not benefit these patients. Patients who have an ND develop after a lucid period may have a thrombosed ICA despite a normal intraoperative duplex, and unless there is a timely normal duplex, re-exploration is recommended and appears to benefit these patients.

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.

Stroke from carotid endarterectomy: when and how to reduce perioperative stroke rate?

OBJECTIVES

To analyse four years of CEA with respect to the underlying mechanisms of perioperative stroke and the role of intraoperative monitoring in the prevention of stroke.

PATIENTS AND METHODS

From January 1996 through December 1999, 599 CEAs were performed in 404 men and 195 women (mean age: 65 years, range: 39-88). All operations were performed under general anaesthesia using computerised electroencephalography (EEG) and transcranial Doppler (TCD). Any new or any extension of an existing focal cerebral deficit, as well as stroke-related death were registered. Perioperative strokes were classified by time of onset (intraoperative or postoperative), outcome (minor or major stroke), and side (ipsilateral or contralateral). Stroke aetiology was assessed intraoperatively by means of EEG, TCD, completion arteriography or immediate re-exploration, and postoperatively by duplex sonography, computerised tomography (CT) or magnetic resonance imaging (MRI) of the head.

RESULTS

Perioperative stroke or death occurred in 20 (3.3%) patients. In four operations stroke was apparent immediately after surgery. Mechanisms of these strokes were ipsilateral carotid artery occlusion (1) and embolisation (3). In 16 patients stroke developed after a symptom-free interval (2-72 h, mean 18 h) due to occlusion of the internal carotid artery on the side of surgery (9). Other mechanisms were: contralateral occlusion of the internal carotid artery (1), postoperative hyperperfusion syndrome (1), intracerebral haemorrhage (1), and contralateral ischaemia due to prolonged clamping (1). In three procedures the cause was unknown.

CONCLUSIONS

In our experience most strokes from CEA developed after a symptom-free interval and mainly due to thromboembolism of the operated artery. We suggest the introduction of additional TCD monitoring during the immediate postoperative phase.

Preprocedural risk stratification: identifying an appropriate population for carotid stenting

PURPOSE

Given the uncertainties associated with carotid angioplasty and stenting, the initial assessment of the procedure may be best undertaken in a subgroup of patients at increased risk for complications with standard carotid surgery. In an effort to characterize such a subgroup, we reviewed the results of carotid endarterectomy in patients with and without significant medical comorbidity.

METHODS

During a 10-year period 3061 carotid endarterectomies were performed at a single institution and entered prospectively into a registry. A high-risk patient subgroup was identified, defined by the presence of severe coronary artery disease, chronic obstructive lung disease, or renal insufficiency. The outcome of carotid endarterectomy was assessed with respect to perioperative stroke, myocardial infarction, or death, as well as the combined end point of one or more of the end points.

RESULTS

The rate of the composite end point stroke/myocardial infarction/death was 3.8% in the total group of 3061 patients who underwent endarterectomy. As individual end points, the rate of stroke was 2.1%, myocardial infarction 1.2%, and death 1.1%. Among the high-risk subset, the composite end point stroke/myocardial infarction/death occurred in 7.4%. This rate was significantly greater than the corresponding rate of 2.9% in the low-risk subset (P <.0005). Similarly, the rate of stroke (3.5% vs 1.7%, P =.008) or death (4.4% vs 0.3%, P <.001) as solitary events was significantly greater in high-risk patients.

CONCLUSIONS

Although carotid endarterectomy is an extremely safe procedure in most patients, results are not as favorable in a high-risk subset with severe coronary, pulmonary, or renal disease. The initial clinical evaluation of carotid stenting might best be undertaken in such a high-risk population, one that comprises patients for whom standard therapy is associated with a high rate of complications.

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

PURPOSE

When managing a new neurologic deficit after carotid endarterectomy (CEA), the surgeon is often preoccupied with determining the cause of the problem, requesting diagnostics tests, and deciding whether the patient should be surgically reexplored. The goal of this study was to analyze a series of perioperative neurologic events and to determine if careful analysis of their timing and mechanisms can predict which cases are likely to improve with reoperation.

METHODS

A review of 2024 CEAs performed from 1985 to 1997 revealed 38 patients who manifested a neurologic deficit in the perioperative period (1.9%). These cases form the focus of this analysis.

RESULTS

The causes of the events included intraoperative clamping ischemia in 5 patients (13.2%); thromboembolic events in 24 (63.2%); intracerebral hemorrhage in 5 (13.2%); and deficits unrelated to the operated artery in 4 (10.5%). Neurologic events manifesting in the first 24 hours after surgery were significantly more likely to be caused by thromboembolic events than by other causes of stroke (88.0% vs. 12.0%, P<.002); deficits manifesting after the first 24 hours were significantly more likely to be related to other causes. Of 25 deficits manifesting in the first 24 hours after surgery, 18 underwent immediate surgical reexploration. Intraluminal thrombus was noted in 15 of the 18 reexplorations (83. 3%); any technical defects were corrected. After the 18 reexplorations, in 12 cases there was either complete resolution of or significant improvement in the neurologic deficit that had been present (66.7%).

CONCLUSIONS

Careful analysis of the timing and presentation of perioperative neurologic events after CEA can predict which cases are likely to improve with reoperation. Neurologic deficits that present during the first 24 hours after CEA are likely to be related to intraluminal thrombus formation and embolization. Unless another etiology for stroke has clearly been established, we think immediate reexploration of the artery without other confirmatory tests is mandatory to remove the embolic source and correct any technical problems. This will likely improve the neurologic outcome in these patients, because an uncorrected situation would lead to continued embolization and compromise.