Hemispheric Transient Ischemic Attacks Research Articles

Endovascular repair of radiation-induced bilateral common carotid artery stenosis and pseudoaneurysms: a case report

BACKGROUNDRadiation-induced damage to small and medium-sized vessels has been observed in both animals and humans. Changes may appear in the immediate postradiation period or many years later. In this case, we report an unusual presentation of bilateral radiation-induced carotid artery stenoses associated with pseudoaneurysms, and a previously unreported application of a recently established treatment.CASE DESCRIPTIONA 72-year-old African-American male presented with recurrent right hemispheric transient ischemic attacks (TIA) and neck pain. Thirteen years previously, the patient had received radiation therapy for laryngeal carcinoma. Diagnostic carotid angiography demonstrated moderate radiation-induced bilateral carotid artery stenosis and associated common carotid pseudoaneurysms. The patient was treated with bilateral endovascular stents and electrolytically detachable coils in staged procedures. At his most recent follow-up, there is no evidence of re-stenosis and the patient remains asymptomatic.CONCLUSIONSThis case illustrates a novel and successful treatment for the endovascular repair of post-radiation bilateral carotid artery stenosis and pseudoaneurysms. In our practice, we have seen three such cases of radiation-induced vasculopathy. Therefore, patients with a previous history of radiation therapy for head and neck neoplasms merit cautious monitoring and judicious use of stents and secondary coils, when necessary.

Types of neurovascular symptoms and carotid plaque ultrasonic textural characteristics.

The aim of this study was to identify the echo morphology and stenosis of carotid plaques that corresponded to ipsilateral asymptomatic status, amaurosis fugax, hemispheric transient ischemic attack, and stroke. One hundred ninety-two plaques (150 patients), producing stenosis in the range of 50% to 99% and associated with various neurovascular manifestations, were studied. These plaques were imaged on duplex scans, and a series of textural features was produced in a computer to distinguish quantitatively their various echo patterns. Amaurosis fugax corresponded to dark, severely stenosed atheromas (90%); hemispheric transient ischemic attack and stroke corresponded to plaques with intermediate echoic characteristics and intermediate stenosis (80%); and asymptomatic status corresponded to bright, moderately stenosed plaques (70%; P < .05). The significance of these findings is discussed.

Carotid endarterectomy in diabetic patients

Objective: The purpose of the current study was to identify the possible short- and long-term effects of diabetes on the outcome of carotid endarterectomy. Methods: Medical records were reviewed for 781 carotid endarterectomies (in 734 patients) performed by the same vascular surgeon in a university medical center between January 1994 and December 1998. Patients were divided two groups: those with diabetes (n = 181 patients; 193 operations) and those without diabetes (n = 553; 588 operations). The two groups were similar with respect to mean age, male-female ratio, and contralateral lesions. The only significant differences were a higher prevalence of peripheral vascular disease and dyslipidemia in the diabetic group and a higher prevalence of hemispheric transient ischemic attacks among the nondiabetic patients. Carotid color duplex ultrasound scan had been performed in all patients, and in 56 patients from the diabetic group and 56 patients from the nondiabetic group (matched for age, sex, and contralateral lesions), the distal extension of the lesion from the carotid bifurcation had also been defined. Both of these subgroups were fully representative of their respective groups of origin. Carotid endarterectomy was performed after the induction of general anesthesia; electroencephalographic monitoring was continuous. Results: Except for the significantly higher prevalence of calcified plaques in the diabetic patients (P <.0001), the characteristics of the carotid disease in the two groups were similar. In the 56-member subgroups, 73.2% of the diabetic and 35.7% of the nondiabetic patients (P <.0001) had lesions extending more than 2 cm beyond the carotid bifurcation. Mean length of plaque beyond the bifurcation was 2.3 ± 0.09 cm for the diabetic and 1.7 ± 0.08 cm for the nondiabetic patients (P <.0001). Diabetes was the only factor significantly correlated with plaque length. In the diabetic subgroup, surgery was characterized by significantly longer carotid arteriotomies (P =.03) and clamp times (P <.003). Operative mortality was 1.5% in the diabetic group (2 myocardial infarctions + 1 stroke) and 0.5% in the nondiabetic group (1 myocardial infarction + 2 strokes; P value not significant); stroke rates were 1.5% (3 major strokes) and 0.5% (2 major strokes + 1 minor stroke), respectively (P = not significant). Long-term survival (5 years) was not significantly lower among the diabetic patients. Conclusions: Diabetes mellitus does not seem to significantly increase the surgical risk for carotid endarterectomy. The presence of more extensive plaques has no significant effect on the results of surgery. (J Vasc Surg 2001;33:148-54.)

New Information on the Value of Plaque Characterisation — Relation to Symptoms

This paper reviews the literature on the significance of carotid plaque echomorphology and degree of stenosis in relation to the different types of cerebrovascular symptomatology (amaurosis fugax, hemispheric transient ischaemic attacks, stroke) and the asymptomatic status. It provides evidence that amaurosis fugax is associated with hypoechoic and severely stenosed plaques, the hemispheric transient ischaemic attacks and stroke are associated with plaques of intermediate echodensity and stenosis while the asymptomatic status is associated with hyperechoic and moderately stenosed plaques.It lends support to the notion that plaque hypoechoicity is associated with embologenicity. It supports the view that the severe carotid stenosis facilitates the opening of the cerebral collateral circulation and that amaurosis fugax is associated with an “opened” cerebral collateral supply as contrasted to the cerebrovascular symptomatology. It proposes the inclusion of the cerebral collateral circulation as a stroke risk factor along with the plaque echomorphology and the degree of stenosis in the natural history studies of asymptomatic individuals with carotid bifurcation plaques.

External Carotid Surgery

External carotid revascularization has been advocated to correct stenoses and obliterate sources of emboli in symptomatic patients with internal carotid artery (ICA) occlusion. Of more than 450 patients undergoing carotid surgery in an 8-year period, eight patients with amaurosis fugax, hemispheric transient ischemic attacks (TIAs), or global symptoms of cerebral ischemia in the presence of ICA occlusion underwent external carotid artery (ECA) reconstruction. There were five external carotid endarterectomies and three bypasses to the ECA, one from the common carotid artery and two from the subclavian artery. There were no operative deaths, but one minor ipsilateral stroke occurred after subclavian-ECA bypass. There was complete resolution of symptoms in all the other patients. Follow-up ranged from 4 months to 10 years (mean 3.4 years). It is concluded that ECA revascularization may be the best treatment option for relieving or improving late neurologic symptoms secondary to cerebral hypoperfusion and/or embolization through ECA collaterals in the presence of ICA occlusion and ECA stenosis.

A Comparison of Cerebral Hemodynamic Parameters between Transient Monocular Blindness Patients, Transient Ischemic Attack Patients and Control Subjects

Purpose: To assess whether patients with transient monocular blindness (TMB) and patients with hemispheric transient ischemic attacks (hTIA) differ from each other with respect to cerebral hemodynamic parameters. Methods: Seventeen TMB patients and 23 hTIA patients with a moderate to severe stenosis or an occlusion of the internal carotid artery (ICA) underwent magnetic resonance (MR) angiography, ¹H MR spectroscopy and transcranial Doppler sonography. Thirty-one control subjects were investigated to obtain reference values for the MR investigations. Quantitative flow was measured in the ICAs, the basilar artery and the middle cerebral arteries (MCA). Metabolic changes in the MCA territory were studied by assessing N-acetyl-aspartate (NAA)/choline ratios and prevalences of lactate. The prevalence of collateral flow was assessed in the circle of Willis and the ophthalmic arteries. The vasomotor reactivity was studied by measuring the CO₂ reactivity of the MCA territories. Results: Quantitative flow in the cerebropetal arteries and the MCAs did not differ between TMB patients and hTIA patients. Also patterns of collateral flow, prevalence of lactate and CO₂ reactivity were similar. The mean ipsilateral NAA/choline ratio was lower in hTIA patients compared with TMB patients (p < 0.01), and was predominantly correlated with symptomatology (p < 0.01), i.e. whether patients had TMB or hTIA, and not with ipsilateral MCA flow (p = 0.2) or ipsilateral CO₂ reactivity (p = 0.7). Conclusion: The results of this study indicate that there are no cerebral hemodynamic differences between TMB patients and hTIA patients. It is therefore unlikely that hemodynamic factors account for differences in clinical characteristics between the two patient groups.

Microembolic Signal Monitoring in Hemispheric Acute Ischaemic Stroke: A Prospective Study

Background and Purpose: There are few data on the occurrence of microembolic signals (MES) in the acute phase of ischaemic stroke. The objective of our work was to systematically study the frequency of MES in non-selected patients with a first-ever hemispheric transient ischemic attack (TIA) or acute cerebral infarction, and to evaluate the clinical usefulness of MES detection. Methods: 182 consecutive patients with hemispheric TIA or acute cerebral infarction, and 54-age-matched healthy controls were studied. Bilateral transcranial Doppler ultrasound (TCD) monitoring was performed for at least 30 min with a mean time from stroke onset to TCD of 69 h. Stroke severity on admission, early recurrent stroke and dependency on discharge were investigated. Results: MES were detected in 20.5% of patients with arterial sources of embolism, 17.1% of patients with potential sources of cardioembolism and 5% of patients with cryptogenic stroke. They were not registered, however, in lacunar infarctions (p < 0.001). Stroke severity on admission of patients with MES was greater than that of patients without MES (47.1 vs. 19.4% with the Canadian Stroke Scale ≤6.5; p = 0.009). Early recurrent stroke was more frequent in patients with MES (11.8%) than in those without MES (4.2%) although the difference was not statistically significant. Multiple logistic regression analysis showed that MES increased the risk of dependency on discharge (odds ratio, 4.2; 95% CI, 1.2–14.9; p = 0.01) independently of age, stroke severity on admission and presence of an arterial or cardiac embolic source. Conclusions: There is a strong association of MES in the acute phase of stroke with known potential arterial and cardiac embolic sources. MES have an independent predictive value of poor outcome.

Is there a potential role for hyoid bone compression in pathogenesis of carotid artery stenosis?

BACKGROUND Blood flow turbulence and increased shear stress, particularly at sites of sudden, marked arterial wall changes, are significant hemodynamic parameters in the pathogenesis of atherosclerosis. We present a case in which we found the hyoid bone protruding into the carotid vessels and may have been contributing, in part, to atherosclerotic carotid stenosis. CASE PRESENTATION An 85-year-old woman presenting with left arm and leg weakness consistent with right hemispheric transient ischemic attack. Magnetic resonance arteriography (MRA) and carotid non-invasive studies revealed a 90% stenosis of the right internal carotid artery. At surgery, the hyoid bone on the right side was projecting into the internal carotid artery, causing indentation. There was associated rotation of the internal and external carotid arteries from their normal position. Right carotid endarterectomy was performed and the lateral one-third of the hyoid bone excised to alleviate the external compression. Postoperative spiral computerized tomography (CT) scan of the carotid vessels demonstrated the extent of hyoid resection as well as rotation of the external and internal carotid arteries. CONCLUSIONS We suggest the possible contribution of hyoid bone compression to the pathogenesis of atherosclerotic carotid artery stenosis. This report also highlights the diagnostic value of CT angiography in the assessment of carotid artery occlusive disease.

Bilateral internal carotid artery occlusion: natural history and surgical alternatives

Purpose and background: Bilateral internal carotid artery occlusion is an extremely rare entity, therefore, studies of the natural history of this disease are lacking in the English literature. The purpose of this study is to analyze the natural history and surgical alternatives for patients with bilateral internal carotid artery occlusion. Patient population and methods: Twenty-one patients with bilateral internal carotid artery occlusion were encountered with a mean age of 61 years (range of 48–73 years). Their clinical presentations included eight with hemispheric transient ischemic attacks, three with amaurosis fugax, five with strokes and five with non-hemispheric transient ischemic attack. Diagnosis was confirmed using carotid duplex ultrasound and angiography. The majority of patients had more than one risk factor for atherosclerosis: smoking in 100%, hyperlipidemia in 14/21 (67%), hypertension in 17/21 (81%), coronary artery disease in 15/21 (71%) and diabetes mellitus in 7/21 (33%). In addition to the usual medical treatment, 13 patients underwent surgical intervention: eight had an external carotid endarterectomy, four had a carotid–subclavian bypass (to increase external carotid or vertebral flow for tight stenosis or occlusion of the common carotid or subclavian artery) and one patient had an ascending aorta to innominate artery bypass. At a mean follow-up of 6 years (range 1–11 years), the overall mortality rates were 11/21 (52%), in the surgical group it was 5/13 (38%) and 6/8 (75%) in the medical group. The causes of death included seven myocardial infarctions (four in the surgical group and three in the medical group) and four strokes (one in the surgical group and three in the medical group). In the surgical group, 2/13 (15%) had late neurological deficits (one hemispheric transient ischemic attack and one stroke), in contrast to 6/8 (75%, three strokes and three hemispheric transient ischemic attacks) in the medical group. Conclusions: Bilateral internal carotid artery occlusions have grave prognoses and should be considered a marker for severe systemic disease. Various cerebrovascular reconstructive procedures, if feasible, may be beneficial for some of these patients.

Epidemiology of stroke

Epidemiology of stroke

Carotid endarterectomy in octogenarians: Early results and late outcome

Purpose: This study was undertaken to determine the safety and efficacy of carotid endarterectomy (CEA) in the octogenarian population at the Cleveland Clinic. Methods: From 1989 to 1995, 182 CEAs were performed among 167 octogenarians (98 men, 69 women) with a mean age of 83 years (median, 83 years; range, 80 to 93 years). One hundred procedures (55%) were performed for severe asymptomatic stenosis, whereas 48 (26%) were performed for hemispheric transient ischemic attacks (TIAs) or amaurosis fugax, 24 (13%) for prior stroke, and 10 (5%) for vertebrobasilar symptoms. Thirteen CEAs (7%) were combined with myocardial revascularization, and another five (3%) represented carotid reoperations. Nine arteriotomies (5%) were closed primarily, whereas the remaining 173 (95%) were repaired using either vein patch angioplasty (141, 77%) or synthetic patches (32, 18%). Two patients were lost to follow-up, but late information was available for 165 patients (180 operations) at a mean interval of 2.7 years (median, 2.4 years; maximum, 7.4 years). Results: Considering all 182 procedures, there were five early (<30 days) postoperative neurologic events (2.7%), including three strokes (1.6%) and two TIAs (1.1%). An additional 15 neurologic events occurred during the late follow-up period, consisting of 11 strokes (6.1%) and four TIAs (2.2%). The Kaplan-Meier estimated 5-year rate of freedom from stroke was 85% (95% confidence interval [CI], 77% to 93%). There was one early postoperative death (0.6%) of cardiac complications 9 days after CEA. The estimated 5-year survival rate was 45% (95% CI, 33% to 57%), and the 5-year stroke-free survival rate was 42% (95% CI, 30% to 53%). Multivariable analysis yielded age at operation ( p = 0.001), abnormal creatinine level ( p = 0.025), and chronic obstructive pulmonary disease ( p = 0.019) as variables that significantly influenced the survival rate. The presence of chronic obstructive pulmonary disease ( p = 0.009) and, surprisingly, a lesser degree of contralateral internal carotid stenosis ( p = 0.003) were found to be significantly associated with stroke after CEA. Causes of late death were cardiovascular in 16 patients (30%), unknown in 13 (24%), carcinoma in six (11%), stroke in six (11%), and miscellaneous in 13 (24%). Conclusions: We conclude that CEA may be safely performed in selected octogenarians with carotid stenosis, and that the majority of these patients live the rest of their lives free from stroke. Therefore, age alone should not exclude otherwise-qualified candidates from consideration for CEA. (J Vasc Surg 1998;27:860-71.)

Juxtalumenal location of plaque necrosis and neoformation in symptomatic carotid stenosis.

The structural features that underlie carotid plaque disruption and symptoms are largely unknown. We have previously shown that the chemical composition and structural complexity of critical carotid stenoses are related to plaque size regardless of symptoms. To further determine whether the spatial distribution of individual plaque components in relation to the lumen corresponds to symptomatic outcome, we evaluated 99 carotid endarterectomy plaques. Indications for operation were symptomatic disease in 59 instances (including hemispheric transient ischemic attack in 29, stroke in 19, and amaurosis fugax in 11) and angiographic asymptomatic stenosis > 75% in 40. Plaques removed after remote symptoms beyond 6 months were excluded. Histologic sections from the most stenotic region of the plaque were examined using computer-assisted morphometric analysis. The percent area of plaque cross-section occupied by necrotic lipid core with or without associated plaque hematoma, by calcification, as well as the distance from the lumen or fibrous cap of each of these features, were determined. The presence of foam cells, macrophages, and inflammatory cell collections within, on, or just beneath the fibrous cap was taken as an additional indication of plaque neoformation. The mean percent angiographic stenosis was 82% +/- 11% and 79% +/- 13% for the asymptomatic and symptomatic groups, respectively (p > 0.05). The necrotic core was twice as close to the lumen in symptomatic plaques when compared with asymptomatic plaques (0.27 +/- 0.3 mm vs 0.5 +/- 0.5 mm; p < 0.01). The percent area of necrotic core or calcification was similar for both groups (22% vs 26% and 7% vs 6%, respectively). There was no significant relationship to symptom production of either the distance of calcification from the lumen or of the percent area occupied by the lipid necrotic core or calcification. The number of macrophages infiltrating the region of the fibrous cap was three times greater in the symptomatic plaques compared with the asymptomatic plaques (1114 +/- 1104 vs 385 +/- 622, respectively, p < 0.009). Regions of fibrous cap disruption or ulceration were more commonly observed in the symptomatic plaques than in the asymptomatic plaques (32% vs 20%). None of the demographic or clinical atherosclerosis risk factors distinguished between symptomatic and asymptomatic plaques. These findings indicate that proximity of plaque necrotic core to the lumen and cellular indicators of plaque neoformation or inflammatory reaction about the fibrous cap are associated with clinical ischemic events. The morphologic complexity of carotid stenoses does not appear to determine symptomatic outcome but rather the topography of individual plaque components in relation to the fibrous cap and the lumen. Imaging techniques that precisely resolve the position of the necrotic core and evidence of inflammatory reactions within carotid plaques should help identify high-risk stenoses before disruption and symptomatic carotid disease.

Microembolic signals with serial transcranial Doppler monitoring in acute focal ischemic deficit. A local phenomenon?

The occurrence of microembolic signals (MES) in patients with transient ischemic attack (TIA) or stroke has already been described, but the diagnostic and prognostic value of this finding is still debated. We evaluated 90 consecutive patients admitted for their first hemispheric TIA or ischemic stroke within 72 hours of onset. All of them underwent 30-minute bilateral transcranial Doppler monitoring of middle cerebral arteries, within 72 hours of onset. The monitoring was repeated after an additional 24 hours and after 7 days. We then classified the episodes in the following etiologic categories: cardioembolic, atherothrombotic, small-vessel disease, mixed cases, unknown origin, and other causes. We included 75 patients, with a mean interval of registration of 32.04 +/- 19.39 hours. There were 9 patients with MES (12%). All MES were recorded only on the symptomatic middle cerebral artery, and the majority were recorded during the first or the second registration. No statistically significant difference was found in risk factors and hematologic parameters. Five patients (56%) had atherothrombotic episodes, 3 patients (33%) had cardioembolic episodes, and 1 patient (11%) had a protein S deficit. No patient with MES had small-vessel disease (P = .01). MES are an infrequent finding in patients with TIA or ischemic stroke within 72 hours of onset, but they can be recorded more easily with serial registration. In our patients, MES were found only on the symptomatic middle cerebral artery and were present in atherothrombotic and cardioembolic episodes but not in small-vessel disease.

Carotid Endarterectomy for Symptomatic Carotid Artery Disease Demonstrated by Duplex Ultrasound With Minimal Arteriographic Findings

Ulcerated or irregular heterogeneous carotid plaque as seen by duplex ultrasound can cause hemispheric transient ischemic attacks (TIAs) and/or a cerebrovascular accident, even if only associated with nonsignificant carotid stenosis on arteriography. The purpose of this study was to review our experience in patients who underwent a carotid endarterectomy after medical treatment had failed, based on pathologic findings detected by carotid duplex ultrasound with minimal disease on arteriography. The medical records of 14 patients who underwent carotid endarterectomy for TIA symptoms related to ulcerated or irregular heterogeneous plaques were analyzed. All had had preoperative carotid duplex ultrasound, arteriography, and cardiac and neurologic workups to rule out other causes for their TIAs. Medical treatment had failed in all of them. There were 10 men and four women whose median age was 68 years. Carotid duplex ultrasound showed irregular heterogeneous carotid plaque in all patients associated with 20% to 50% stenosis in 12 and approximately 50% to 60% stenosis in two. All had normal to < 20% stenosis on arteriograms. The duplex ultrasound findings were all confirmed at operation. All had an uneventful postoperative course with relief of symptoms. Carotid duplex ultrasound is superior to carotid arteriography in detecting irregular or ulcerative heterogeneous plaque associated with nonsignificant stenosis. Carotid duplex ultrasound can be used to determine the desirability of carotid endarterectomy after failed medical treatment in patients with classical and persistent TIA symptoms despite normal or minimal disease on arteriograms. A successful endarterectomy appears to predict an asymptomatic postoperative course.

Subclavian-Carotid Bypass to an “Isolated” Carotid Bifurcation: A Retrospective Analysis

Most patients with occlusion of the common carotid artery will have concomitant occlusion of the internal and external carotid arteries. A few, however, will maintain antegrade internal carotid flow via retrograde flow from the ipsilateral external carotid artery. These patients remain at risk for hemispheric transient ischemic attacks (TIAs), ischemic stroke, or vertebrobasilar insufficiency/global cerebral ischemia. Historically, diagnosis of this condition has relied on cerebral arteriography and/or blind exploration of the carotid bifurcation. More recently, color-enhanced duplex ultrasonography has been used to facilitate the diagnosis and has allowed focused, delayed arteriographic views of the appropriate carotid bifurcation, making blind exploration unnecessary. From 1985 to 1994, nine patients with TIAs (n = 5), completed stroke with minimal residual deficit (n = 2), or vertebrobasilar insufficiency (n = 2) were found to have occlusion of the common carotid artery with a patent carotid bifurcation on duplex ultrasound images. All nine had this particular anatomic condition confirmed by arteriography and were subsequently treated by subclavian-carotid bypass using autologous reversed saphenous vein (n = 5) or synthetic (n = 4) grafts. Five of nine patients required concomitant bifurcation endarterectomy. There were no perioperative strokes or TIAs and no operative deaths. Six of eight survivors remain asymptomatic at 1 to 92 months' follow-up (mean 37.1 months). Symptomatic patients with occluded common carotid arteries and patent bifurcations can be treated surgically with low operative morbidity and good long-term results.

Magnetic resonance imaging correlates of transient cerebral ischemic attacks.

MRI of patients with a transient ischemic attack (TIA) may provide more detailed morphological insights than CT. We therefore studied the frequency and type of TIA-related infarcts shown by MRI, examined the utility of intravenous contrast material, and searched for potential predictors of infarct occurrence. We performed 1.5-T MRI of the brain of 52 patients (age range, 28 to 93 years; mean, 61 years) with a hemispheric TIA. Contrast material (Gd-DTPA) was given to 45 individuals. We recorded type, number, size, and location of ischemic brain lesions and related the presence of acute infarction to features of clinical presentation and probable causes for the TIA. MRI showed focal ischemic lesions in 50 patients (81%), but an acute TIA-associated infarct was seen in only 19 subjects (31%). In patients with an acute lesion, the infarcts were smaller than 1.5 cm in 13 (68%), purely cortical in 11 (58%), and multiple in 7 (37%) individuals. Contrast enhancement contributed to the delineation of an acute lesion in only 2 of 45 patients (4%). Acute infarction was unpredictable by clinical TIA features, but the frequency of identifiable vascular or cardiac causes was significantly higher in those patients with TIA-related morphological damage (odds ratio, 5.2 [95% confidence interval, 1.6 to 17.3]). More than two thirds of TIA patients showed no associated brain lesion even when MRI and contrast material were used, but the overall frequency of ischemic damage was high. TIA-related infarcts on MRI were mostly small and limited to the cortex and tended to consist of multiple lesions. A positive MRI underscores the need for comprehensive diagnostic workup since evidence of infarction appears to be associated with a higher frequency of significant vascular or cardiac disorders.

Post-Carotid-Endarterectomy Intracerebral Hemorrhage: A Continuing Challenge

Over the past decade, 2 men and 2 women, ranging in age from sixty-two to seventy-seven (mean, 69.8) years, experienced strokes due to intracerebral hemorrhage within the first four days following uncomplicated carotid endarterectomy (CEA). All operatedon lesions were greater than 90% stenotic, and the contralateral internal carotid artery (ICA) was completely occluded in 3 patients and greater than 90% stenotic in the other patient. All 4 patients had a history of transient ischemia, including hemispheric transient ischemic attacks (TIAs) in 2, hemispheric and nonhemispheric TIAs in 1, and nonhemispheric TIAs in the fourth patient. None had experienced a prior stroke, and computed tomography (CT) scans of the head performed preoperatively in 2 patients were negative. Three patients had a history of hypertension and all 4 required pharmacologic treatment for hypertension intraoperatively and/or during the first postoperative day in the intensive care unit. Three patients died and the fourth recovered. Intracerebral hemorrhage is an infrequent and serious potential complication of CEA. Patients who undergo operation for critical ICA stenoses in the setting of severe contralateral ICA disease appear particularly vulnerable.

Carotid endarterectomy and local intraarterial thrombolysis: Simultaneous procedure in acute occlusion of the internal carotid artery and middle cerebral artery embolism

Patients with severe neurologic deficits caused by acute occlusion of the internal carotid artery represent a prognostically unfavorable group with a persistent neurologic deficit of 40% to 69% and a mortality rate of 16% to 55%.1Meyer FB Sundt Jr, TM Piepgras DG Sandok BA Forbes G. Emergency carotid endarterectomy for patients with acute carotid occlusion and profound neurological deficits.Ann Surg. 1986; 203: 82-89Crossref PubMed Scopus (199) Google Scholar We report a case of a 66-year-old man with symptomatic stenosis of the left internal carotid artery (> 90%). Two weeks before he was admitted, he had two left hemispheric transient ischemic attacks with right arm and facial weakness. At the first neurologic examination a 90% stenosis of the internal carotid artery was diagnosed by Doppler study and magnetic resonance angiography. The computed tomography scan of the brain revealed small lacunar infarctions but no fresh cortical ischemia. Carotid endarterectomy of the symptomatic carotid artery stenosis was recommended, but the patient refused any treatment until a third episode of brachiofacial weakness occurred. After he was admitted to the Department of Vascular Surgery, the patient had a severe left hemispheric stroke even though he was given therapeutic levels of heparin (25,000 IU intravenously daily), with complete hemiplegia of the right side, global aphasia, and progressing lack of consciousness. Acute carotid artery occlusion was diagnosed (Doppler study, loss of bruit), and emergency operation by carotid endarterectomy was performed. Intraoperative needle-angiography after eversion endarterectomy revealed partial occlusion of the middle cerebral artery ( Fig. 1 ). We performed additional intraoperative lysis-therapy via the reconstructed internal carotid artery (500,000 IU urokinase). Three hours after operation the patient's hemiplegia and aphasia diminished step-by-step, and after 24 hours the patient recovered almost completely from his neurologic deficits. A selective carotid angiogram obtained 3 days later showed evidence of a normal intracerebral vascular architecture with no residual thromboembolism ( Fig. 2 ). Fig. 2Selective angiography of left carotid artery 3 days after eversion endarterectomy: extracranial part of internal carotid artery (A), intracerebral internal carotid artery with patent middle cerebral artery (B,C).View Large Image Figure ViewerDownload (PPT)Fig. 2Selective angiography of left carotid artery 3 days after eversion endarterectomy: extracranial part of internal carotid artery (A), intracerebral internal carotid artery with patent middle cerebral artery (B,C).View Large Image Figure ViewerDownload (PPT)Fig. 2Selective angiography of left carotid artery 3 days after eversion endarterectomy: extracranial part of internal carotid artery (A), intracerebral internal carotid artery with patent middle cerebral artery (B,C).View Large Image Figure ViewerDownload (PPT)At discharge from the hospital, the patient was free of complaint. A last neurologic examination indicated only a slight weakness of a facial branch and signs of dysdiadochokinesia of the right arm. Although several series of emergency carotid endarterectomies with sometimes dramatic recovery have been presented, acute stroke is generally considered as a contraindication to carotid endarterectomy, with rare exceptions in individual cases.2Gertler JP Blankensteijn JD Brewster DC et al.Carotid endarterectomy for unstable and compelling neurologic conditions: Do results justify an aggressive approach.J VASC SURG. 1994; 19: 32-42Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar, 3Moore WS Mohr JP Najafi H Robertson JT Stoney RJ Toole JF. Carotid endarterectomy: practice guidelines—report of the Ad Hoc Committee to the Joint Council of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery.J VASC SURG. 1992; 15: 469-479Abstract Full Text Full Text PDF PubMed Scopus (125) Google Scholar The reasons for this include neurologic instability and fear of clinical deterioration by secondary hemorrhage in the infarcted area. It has been demonstrated that acute cerebrovascular arterial occlusion could be treated successfully by local intraarterial and systemic lysis-therapy.4Del Zoppo GJ Pessin MS Mori E Hacke W. Thrombolytic interventions in acute thrombotic and embolic stroke.Semin Neurol. 1991; 11: 368-384Crossref PubMed Scopus (85) Google Scholar, 5Higashida RT Van Halbach V Barnwell SL Dowd CF Hieshima GB. Thrombolytic therapy in acute stroke.J Endovasc Surg. 1994; 1: 4-15Crossref PubMed Scopus (35) Google Scholar Failure of lysis-therapy of an acute carotid artery occlusion can occur in patients with a preexisting high-grade stenosis. Also thrombolysis is not able to treat atherosclerotic carotid artery stenosis sufficiently from a surgical point of view because a high-grade carotid artery stenosis remains, causing the risk of ongoing embolism. Therefore simultaneous carotid endarterectomy and intraoperative lysis-therapy may be a therapeutic alternative in the treatment of acute ischemic stroke by carotid artery occlusion and middle cerebral artery thromboembolism. This is the first case of a simultaneous emergency carotid endarterectomy and intraoperative thrombolysis in the treatment of acute carotid artery occlusion and middle cerebral artery embolism in the literature. This procedure should be taken into consideration in the treatment of acute stroke in patients with a preexisting high-grade carotid artery stenosis.

Asymptomatic Carotid Stenosis and Risk of Stroke: A Natural History Study

In patients with asymptomatic carotid stenosis &gt;70% diameter, the annual incidence of ipsilateral stroke is 3-4%. Multicentre randomised studies such as the asymptomatic carotid atherosclerosis study (ACAS) in the U.S.A. and the ACST in Europe aim to answer the question whether carotid endarterectomy can reduce the incidence of stroke in such patients. If the surgical risk is too close to benefit or if a high proportion of patients not at risk of stroke are entered into the ACAS or ACST studies, the latter may fail to demonstrate the benefit of carotid endarterectomy (CE). The need to identify a high risk stroke group (ipsilateral stroke &gt;7% per annum) with randomisation of this group to a subsequent study will then become apparent. If the ACAS and ACST studies indicate that the risk of stroke is reduced by 50% (i.e., from 4 to 2%), it has been calculated that the cost of preventing one stroke will be 1.2 million US dollars because of the large number of operations required. It will still be necessary to identify a high-risk group or, better, a low-risk group in order to spare many patients unnecessary operation. A multicentre, natural history study has been set up under the auspices of the International Union of Angiology and monitored from St Mary's Hospital Medical School in London with over 50 centres taking part. Patients with asymptomatic carotid stenosis 50-70% and 70-90% are entered in a ratio of 1 to 2, a number of noninvasive tests are performed, and the patients are followed for 5 years. The tests performed are (a) Grading the degree of internal carotid stenosis using duplex scanning; (b) grading the opposite side; (c) plaque characterisation; (d) presence of ultrasonic ulceration; (e) plaque thickness (mm); (f) cerebral reactivity to CO2using velocity of internal carotid artery and (optional) middle cerebral artery ; (g) CT brain scan for the presence of silent infarction ; (h) intima-media thickness of the common carotid; and (i) identification of conventional risk factors: hypertension, hypercholeterolaemia, smoking, family history, diabetes. The key end points are stroke (including fatal stroke) and ipsilateral stroke. Patients who die from cardiovascular death other than stroke or noncardiovascular death and patients who develop hemispheric transient ischaemic attacks followed by CE are considered to have reached an exit end point. Because this is a natural history study, the clinician in charge of all patients is free to treat them in any way considered appropriate. Patients in the Medical Limb of the ACST study may be entered into the Natural History (ACSRS) study.

The Risk of Stroke in Patients With First-Ever Retinal vs Hemispheric Transient Ischemic Attacks and High-grade Carotid Stenosis

The prognosis of amaurosis fugax has been considered to be favorable compared with that of hemispheric transient ischemic attacks. However, this has remained uncertain for patients with significant carotid stenosis as the assessment of progression of the disease has been confounded when patients undergo carotid endarterectomy. In the North American Symptomatic Carotid Endarterectomy Trial, patients with high-grade (70% to 99%) carotid stenosis were randomized to receive either medical or surgical treatment, thus making an unconfounded analysis possible. We identified 129 medically treated patients with high-grade carotid stenosis who had their first-ever transient ischemic attack as the entry event into the trial. Fifty-nine patients with retinal transient ischemic attacks (RTIAs) were compared with 70 patients with hemispheric transient ischemic attacks (HTIAs). Patients with HTIAs were older, with a higher prevalence of most risk factors for stroke. Average time of delay from the onset of transient ischemic attacks to medical treatment was longer for patients with RTIAs than for patients with HTIAs (48.5 vs 15.2 days). Kaplan-Meier estimates of the risk of ipsilateral stroke at 2 years were 16.6% +/- 5.6% for patients with RTIAs and 43.5% +/- 6.7% for patients with HTIAs (P = .002 for the difference in risk between RTIAs and HTIAs). From corresponding Cox's proportional hazards regression analyses, the risk of ipsilateral stroke ranged from 11.2% to 28.9% for patients with RTIAs and from 37.4% to 96.3% for patients with HTIAs across stenoses, spanning 75% to 95%. Overall, the relative risk of ipsilateral stroke (HTIAs compared with RTIAs) was 3.23 (95% confidence interval, 1.47 to 7.12), regardless of the degree of high-grade stenosis. To our knowledge, this study is the first report on the expected outcome for medically treated patients with high-grade (70% to 99%) carotid stenosis in whom the first-ever event was either an RTIA or HTIA. The presence of RTIAs carries a considerable risk of ipsilateral strokes, particularly at higher degrees of stenosis. However, in comparison with HTIAs, patients with RTIAs still have a better prognosis.