Clinical outcome of patients with internal carotid artery occlusion: a prospective follow-up study

Assessment of Apparent Internal Carotid Tandem Occlusion on High-Resolution Vessel Wall Imaging: Comparison with Digital Subtraction Angiography

BACKGROUND AND PURPOSE

Not all tandem occlusions diagnosed on traditional vascular imaging modalities, such as MRA, represent actual complete ICA occlusion. This study aimed to explore the utility of high-resolution vessel wall imaging in identifying true ICA tandem occlusions and screening patients for their suitability for endovascular recanalization.

MATERIALS AND METHODS

Patients with no signal in the ICA on MRA were retrospectively reviewed. Two neuroradiologists independently reviewed their high-resolution vessel wall images to assess whether there were true tandem occlusions and categorized all cases into intracranial ICA occlusion, extracranial ICA occlusion, tandem occlusion, or near-occlusion. DSA classified patient images into the same 4 categories, which were used as the comparison with high-resolution vessel wall imaging. The suitability for recanalization of occluded vessels was evaluated on high-resolution vessel wall imaging compared with DSA.

RESULTS

Forty-five patients with no ICA signal on MRA who had available high-resolution vessel wall imaging and DSA images were included. Among the 34 patients (34/45, 75.6%) with tandem occlusions on DSA, 18 cases also showed tandem occlusions on high-resolution vessel wall imaging. The remaining 16 patients, intracranial ICA, extracranial ICA occlusions and near-occlusions were found in 2, 6, and 8 patients, respectively, on the basis of high-resolution vessel wall imaging. A total of 20 cases (20/45, 44.4%) were considered suitable for recanalization on the basis of both DSA and high-resolution vessel wall imaging. Among the 25 patients deemed unsuitable for recanalization by DSA, 11 were deemed suitable for recanalization by high-resolution vessel wall imaging.

CONCLUSIONS

High-resolution vessel wall imaging could allow identification of true ICA tandem occlusion in patients with an absence of signal on MRA. Findings on high-resolution vessel wall imaging can be used to screen more suitable candidates for recanalization therapy.

Natural History of Symptomatic and Asymptomatic Carotid Artery Occlusion Contralateral to Carotid Endarterectomy: A Prospective Study

The natural history of carotid occlusion (CO) has generally been analyzed in the presence of a contralateral patent but diseased internal carotid artery (ICA). Few previous studies have focused on the fate of CO contralateral to the side of a prior carotid endarterectomy (CEA). The aim of this study was to analyze the mortality rate and the incidence of cerebrovascular events in the hemisphere ipsilateral to CO (HICO) in patients who had undergone contralateral CEA. The 30-day and long-term outcomes of 153 consecutive patients who had CEA for severe symptomatic and asymptomatic ICA lesions contralateral to a symptomatic or asymptomatic CO over a 15-year period were considered. The endpoints of the study were mortality and neurological events in the HICO. Overall, the 30-day mortality and stroke rates were 0.6% (1/153) and 1.9% (3/153), respectively; the only death was stroke-related and the stroke was ipsilateral to the operated side. The other 2 strokes were ipsilateral to a symptomatic CO. The follow-up was completed for all patients (mean, 7.7 years; range, 1-172 months). Overall, there were 4 late strokes (2.6%), one of them lacunar in a patient with a symptomatic CO, whereas the other 3 were atheroembolic and ipsilateral to the operated ICA. The risk of late stroke in the HICO at 5 and 12 years was 2%. Overall, there were 19 late deaths, none of them stroke-related. CO, with or without symptoms, contralateral to CEA could be considered a locally benign condition in the long term.

Acute symptomatic extracranial internal carotid occlusion - natural course and clinical impact

Background: To assess the vascular and clinical course of acute symptomatic extracranial internal carotid artery (ICA) occlusion. Patients and methods: Patients with an acute ischemic event in the anterior circulation and corresponding extracranial ICA occlusion at CT angiography and/or color-coded duplex sonography underwent recurrent duplex follow-up for detection of spontaneous recanalization. Stroke recurrence and functional outcome 4.5 months after the ischemic index event assessed by modified Rankin scale served as secondary outcome parameters. Results: 133 patients (91 men, mean age 62.3 years, SD 10.8) demonstrated symptomatic occlusion of the extracranial ICA with open intracranial ICA and open middle cerebral artery and were followed-up for spontaneous recanalization. Twenty-eight recanalized spontaneously, 25 to high-grade focal stenosis within 12 days, revealing an early cumulative recanalization rate of 23 %. Detection of recanalization was independently associated with de novo dual anti-platelet therapy (adjusted odds ratio [OR], 3.24; 95 % confidence interval [CI], 1.34 to 7.80). Ischemic recurrence occurred in 16 patients, of which 10 deemed to be embolic and 5 hemodynamic. Spontaneous ICA recanalization and an exhausted cerebrovascular reserve in the hemisphere distal to the occluded ICA were both independently associated with the occurrence of a recurrent ischemic event at Cox regression. An increasing NIHSS score at admission, a decreasing middle cerebral artery flow velocity and an ischemic recurrence independently predicted poor outcome (modified Rankin scale 3 to 6) in multivariate analysis. Conclusions: Acute symptomatic extracranial ICA occlusion is an unstable condition with frequent spontaneous recanalization to severe stenosis and early embolic stroke recurrence, demanding appropriate prevention especially in those patients with only mild deficit.

Prognosis of patients with late spontaneous recanalization of the atherosclerotic occlusion of internal carotid arteries: A pilot case series

Late spontaneous recanalization (SR) of an occluded internal carotid artery (ICA) has been rarely reported and the prognosis of affected patients remains elusive. In the present study, the incidence of late SR of atherosclerotic occlusion of the ICA and associated outcomes were assessed in a single center. A total of 36 patients with ICA occlusion, who underwent carotid artery stenting or vertebral artery stenting in arteries other than the occluded ICA, were prospectively included and followed up for ≥18 months. SR was diagnosed by color Doppler ultrasound imaging. The incidence of late SR, the functional outcome and the incidence of adverse cardiovascular events in these patients were evaluated. During the follow-up, three patients had late SR of the occluded ICA (8.3%). All patients had vascular events prior to the confirmation of late SR of the ICA. Subsequent to SR, the patients were clinically stable with preserved functional ability, based on the Modified Rankin Scale. Of these patients, one suffered from re-occlusion of the recanalized ICA without presenting with any novel significant symptoms. In conclusion, patients with late SR of the ICA appear to have preserved functional ability and favorable clinical outcomes. Large-scale cohorts are required to determine the clinical characteristics that contribute to the incidence of late SR of the ICA.

Characterization and Natural History of Patients with Internal Carotid Occlusion: A Comparative Study

BACKGROUND

To characterize patients with internal carotid occlusion (ICO) with respect to demographic data, associated diseases, medical management, and risk factors and to compare these patients with those with nonsignificant stenosis (NSS; less than 50% stenosis). Secondary end points were new neurologic events, progression of contralateral degree of stenosis, cardiovascular symptoms, and death during follow-up.

METHODS

Retrospective analysis was performed using data collected from clinical records and added to a prospective database. Missing data were obtained during phone interviews or requested medical appointments.

RESULTS

From 2005 to 2013, 213 patients with ICO and 172 with NSS were studied (medium follow-up 37.81 months). Among the patients with ICO, a greater proportion were men, had a history of smoking, and presented with peripheral arterial disease and a lower creatinine clearance compared with those with NSS (P < 0.05). At the time of diagnosis, 76.1% of the patients with ICO were symptomatic compared with 35.5% of those with NSS (P = 0.000001). The patients in the ICO group exhibited significant progression of contralateral stenosis compared with those in the control group with progression on any side (15.0% vs. 2.3%, P = 0.00011). In addition, 18 patients in the ICO group (8.5%) exhibited new neurological symptoms compared with 13 (7.6%) in the NSS group (P = 0.41). When the ICO and NSS groups were combined, 10.8% of the initially symptomatic patients presented with new symptoms compared with 4.3% of those who were initially asymptomatic (P = 0.0218). The number of deaths was significantly higher among the patients in the ICO group (14.1% vs. 6.4%, P = 0.0150).

CONCLUSIONS

Patients presenting with ICO have more risk factors and higher mortality by any cause. Initially, symptomatic patients will likely present with more neurological symptoms during follow-up, independent of carotid morphology, ICO, or NSS. Efforts must be made to identify those at risk before occlusion and to prevent secondary events and death.

Predictive Factors for the Spontaneous Recanalization of Large and Middle Cerebral Arteries after Acute Occlusion

OBJECTIVE

This study aims to investigate the predictive factors for the spontaneous recanalization of occluded arteries in patients with acute ischemic stroke.

METHODS

A total of 139 patients with consecutive acute ischemic stroke were enrolled from June 2010 to June 2013. The clinical and biochemical parameters were measured in each participant. Occlusion and recanalization of the carotid artery, the middle cerebral artery, and the vertebral and basilar arteries were identified by using computed tomographic angiography or digital subtraction angiography.

RESULTS

Among the 139 patients, 23 showed spontaneous recanalization, whereas 116 did not. In the patients with spontaneous recanalization, the proportion of atrial fibrillation was significantly lower (0% versus 29.31%, P= .01), whereas the proportion of stage 3 hypertension was significantly higher (60.87% versus 32.76%, P= .01) than that of those without recanalization. Logistic regression analysis showed that the proportion of atrial fibrillation was negatively (odds ratio [OR]: .117, 95% confidence interval [CI]: .015-.918, P= .04) associated with spontaneous recanalization, whereas the proportion of stage 3 hypertension was positively (OR: 4.316, 95% CI: 1.533-12.154, P= .01) associated with it.

CONCLUSIONS

Atrial fibrillation is associated with reduced spontaneous recanalization of the large and middle cerebral arteries in patients after acute ischemic stroke-induced occlusion, whereas stage 3 hypertension may contribute to the promotion of the recanalization.

Prognosis of Asymptomatic Carotid Artery Occlusion

Background and Purpose—

The aim of this systematic review was to quantify the risk of ipsilateral stroke in patients with asymptomatic carotid artery occlusion (ACAO).

Methods—

Studies reporting ipsilateral stroke risk in ACAO were identified by a search of MEDLINE, EMBASE, and study bibliographies. Study estimates were pooled using a random effects model, and heterogeneity was quantified using the I 2 statistic. The primary outcome was the annual rate of ipsilateral stroke.

Results—

Thirteen studies were identified, encompassing 718 patients with ACAO who were followed up for a median of 2.8 years. The annual rate of ipsilateral stroke was 1.3% (95% confidence interval, 0.4–2.1; I 2 =53%). The annual rate of ipsilateral transient ischemic attack was 1.0% (95% confidence interval, 0.3–1.8; I 2 =40%). The annual rate of death was substantially higher at 7.7% (95% confidence interval, 4.3–11.2; I 2 =83%). Correction for possible publication bias for the primary outcome suggested a lower risk of ipsilateral stroke (0.3% per year; 95% confidence interval, –0.4 to 1.1).

Conclusions—

Stroke in ACAO is relatively infrequent, but patients face high mortality rates. This suggests the need for intensified medical therapy in ACAO.

Can contrast-enhanced ultrasound with second-generation contrast agents replace computed tomography angiography for distinguishing between occlusion and pseudo-occlusion of the internal carotid artery?

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with a second-generation contrast agent in distinguishing between occlusion and pseudo-occlusion of the cervical internal carotid artery, comparing it with that of conventional Doppler ultrasound and the gold standard, computed tomography angiography.

METHOD

Between June 2006 and June 2012, we screened 72 symptomatic vascular surgery outpatients at a public hospital. Among those patients, 78 cervical internal carotid arteries were previously classified as occluded by Doppler ultrasound (without contrast). The patients were examined again with Doppler ultrasound, as well as with contrast-enhanced ultrasound and computed tomography angiography. The diagnosis was based on the presence or absence of flow.

RESULTS

Among the 78 cervical internal carotid arteries identified as occluded by Doppler ultrasound, occlusion was confirmed by computed tomography angiography in only 57 (73.1%), compared with 59 (77.5%) for which occlusion was confirmed by contrast-enhanced ultrasound (p>0.5 vs. computed tomography angiography). Comparing contrast-enhanced ultrasound with Doppler ultrasound, we found that the proportion of cervical internal carotid arteries classified as occluded was 24.4% higher when the latter was used (p<0.001).

CONCLUSIONS

We conclude that, in making the differential diagnosis between occlusion and pseudo-occlusion of the cervical internal carotid artery, contrast-enhanced ultrasound with a second-generation contrast agent is significantly more effective than conventional Doppler ultrasound and is equally as effective as the gold standard (computed tomography angiography). Our findings suggest that contrast-enhanced ultrasound could replace computed tomography angiography in this regard.

Natural history of carotid artery occlusion

Carotid artery occlusion (CAO) is a risk factor for stroke ipsilateral to the occlusion and puts patients in a high-risk category when contralateral endarterectomy is performed. The purpose of this study was to evaluate the long-term outcomes of patients with internal CAO and to determine risk factors predictive of subsequent neurological event, contralateral carotid intervention, or death. Patients with internal CAO shown by duplex ultrasonography were retrospectively identified and followed between January 2002 and June 2010 (follow-up: 1-101 months, mean: 52 months) at a tertiary care hospital. All had multiple duplex examinations available for review. Chi-square analysis was used to determine risk factors for neurologic event, contralateral intervention, or all-cause morality. Multivariate Cox proportional hazard analysis was conducted using univariate risk factors with P values <0.1. Survival was estimated using the Kaplan-Meier method (P < 0.05 significant). Eighty patients with internal CAO were identified and available for analysis. On initial encounter, 30 (38%) were symptomatic, with 26 (87%) having symptoms referable to the side of the occluded internal carotid artery. During follow-up, seven (9%) had a neurologic event, of which six (86%) were referable to the occluded side; 14 (18%) patients underwent a contralateral operation. Nineteen (24%) patients died during the period of study. Although numerous variables of multivessel disease were significant with χ(2) analysis, there was no significant risk factor associated with neurologic event on multivariate analysis. However, the development of a hemodynamically significant stenosis (>50%) or occlusion of the external carotid artery (ECA) ipsilateral to the occlusion on follow-up (P < 0.027) was associated with increased risk of death. Kaplan-Meier analysis showed 7-year survival for patients with ECA disease at follow-up was significantly worse (16.2% ± 10.3% [n = 21] vs. 79% ± 8.7% [n = 59]; P < 0.00001). Frequently, patients present with neurological symptoms referable to the side of the internal CAO. Eighty-six percent of neurologic events that occur in follow-up are attributable to the side of the occluded carotid, indicating that the occluded side continues to contribute to neurologic morbidity over time. Multivariate analysis revealed no single factor to be predictive of subsequent neurologic events. With significant risk of death in patients found to have ipsilateral ECA stenosis during follow-up, it seems reasonable to continue surveillance of the occluded carotid.

Late spontaneous recanalization of chronic middle cerebral artery occlusion

Early spontaneous recanalization of the middle cerebral artery in acute ischemic phase artery is not uncommon, whereas the late spontaneous recanalization of chronic occluded artery is a very rare phenomenon and exact incidence and the timing of this event have not been quantified. We present a case in which late spontaneous recanalization of long-lasting middle cerebral artery occlusion occurred in the absence of surgical, endovascular and thrombolytic treatments.

Spontaneous recanalization of the occluded internal carotid artery. A report of two cases

Spontaneous recanalization of the occluded internal carotid artery (ICA) is more frequent than is generally believed. The timing of spontaneous recanalization remains unclear but it may occur as either an early or a late event. The aim of this case report is to emphasize the importance of spontaneous recanalization and its consequences. From September 2008 to November 2010 we prospectively followed patients with old ICA occlusion. The diagnoses of an occlusion were based on duplex scan findings and were confirmed by CT angiography and digital subtraction angiography (DSA). ICA occlusions secondary to dissection, inflammatory process, like fibromuscular dysplasia, previous stenting or endarterectomy and trauma, were excluded from the study. All patients had a scheduled carotid duplex scan every six months. Overall 65 patients were enrolled. Two patients showed evidence of spontaneous recanalization. A 55-year-old man with a known history of transient ischemic attack had occlusion in the left side ICA. He presented with another TIA eight months later. Investigations showed evidence of rcanalization of occluded ICA. This artery underwent uneventful stenting. In another patient recanalization was heralded by global aphasia and right side hemiplegia. He was a 70-year-old man with a history of recurrent TIA. Carotid duplex scan and DSA showed recanalization of the occluded left ICA accompanied by occlusion of the ipsilateral middle cerebral artery. He remained profoundly disabled with severe neurological deficits. In conclusion, spontaneous recanalization of the occluded internal carotid artery is a potentially complicated event that may lead to severe neurological disability.

Spontaneous recanalization of internal carotid artery occlusion

We present a case of spontaneous recanalization of the internal carotid artery (ICA) that occurred in a 51-year-old male patient. The occlusion of the right ICA was asymptomatic and was detected incidentally during imaging of the opposite carotid artery. The patient underwent neuroradiologic analysis and a tapered, flame-like occlusion suggestive of the right ICA dissection was detected. One month later, a carotid Doppler ultrasound demonstrated patent right carotid artery with normal spectral flow. Five-month follow-up showed that the ICA remained patent.

Spontaneous Recanalization of Chronic Internal Carotid Artery Occlusions: Report of 3 Cases

Spontaneous recanalization of a chronically occluded internal carotid artery (ICA) is a rare occurrence. The authors report 3 patients who had documented total occlusion of the ICA followed by late spontaneous recanalization with subsequent high-grade stenosis. The patients in this series had occlusions for 11 months, 36 months, and 39 months, respectively. One patient had symptoms ipsilateral to the recanalized vessel, and 2 patients were asymptomatic. Endarterectomy was performed uneventfully in 2 patients and pathologic specimens demonstrated typical atherosclerotic plaque with patent lumens. Our experience demonstrates that although chronic recanalizations of occluded ICAs are rare, this does occur. Pathology demonstrates typical atherosclerotic plaque which appeared to have been recanalized by lysis of thrombus. The natural history of this condition is not well known and indications for intervention are not well established.

Are Kinking and Coiling of Carotid Artery Congenital or Acquired?

Dolichoarteriopathies consist of tortuosity, kinking, or coiling of the extracranial carotid arteries. Some authors consider these alterations a consequence of atherosclerotic vessel remodeling, while others ascribe them to anatomical variations of embryological origin. The objective was to establish whether carotid dolichoarteriopathies belonged to a congenital origin or to acquired conditions. Color Doppler ultrasonography of neck vessels was performed in 885 participants, whose age ranged from 1-day-old infants to 90-year-old adults. Prevalence of kinking and coiling was evaluated, and it was related to the presence of cardiovascular risk factors. Prevalence of either kinking or coil of carotid arteries showed no increase with age, as it was comparable across all ages; furthermore, frequency of these alterations showed no relationship to cardiovascular risk factors nor to the presence of atheromatous plaques. These findings suggest that carotid dolichoarteriopathies are a result of alterations in embryological development rather than vascular remodeling secondary to aging and/or atherosclerosis.

Recanalization of Chronic Carotid Occlusion: Case Report and Review of the Literature

Recanalization of an occluded extracranial internal carotid artery is a rare event. The mechanism remains unclear. We report a case of recanalized internal carotid artery in its extracranial portion. The patient underwent successful carotid endarterectomy.

Assessment of apparent internal carotid occlusion on ultrasound: prospective comparison of contrast-enhanced ultrasound, magnetic resonance angiography and digital subtraction angiography

OBJECTIVES

Modern conventional ultrasound is sensitive to slow flow, but may misclassify some tight stenoses as occlusion. Symptomatic patients with tight proximal internal carotid artery stenoses may benefit from carotid endarterectomy but those with occlusion or long-segment disease do not.

DESIGN

A prospective study of the diagnostic accuracy of contrast-enhanced ultrasound (CE-US), 2D time-of-flight magnetic resonance angiography (2D-TOF MRA) and contrast-enhanced magnetic resonance angiography (CE-MRA) against a reference standard of digital subtraction angiography (DSA) in patients with apparent carotid occlusion on conventional ultrasound.

MATERIALS AND METHODS

Thirty-one patients with apparent carotid occlusion on conventional ultrasound and with recent ispilateral hemispheric transient ischaemeic attacks (TIAs) were studied. The primary endpoint was confirmation of occlusion with a secondary endpoint of identification of a surgically correctible lesion.

RESULTS

The sensitivity and specificity of CE-US, 2D-TOF MRA and CE-MRA for patency were 1 & 1, 0.33 & 1 and 0.6 & 1 respectively and for the detection of a surgically correctible lesion were 1 & 0.96, 0.67 & 1 and 1 and 0.96 respectively. CE-US was difficult to interpret, precluding confident diagnosis in 5 cases.

CONCLUSIONS

2D-TOF MRA had poor sensitivity for patency and cannot be recommended as a second-line investigation to assess vessels apparently occluded on conventional ultrasound. Confident diagnosis on CE-US and CE-MRA accurately identified occlusion. If occlusion is confirmed by either of these modalities, no further imaging is required. The relative advantages of CE-US or CE-MRA in this situation are uncertain.

Recanalização espontânea tardia de carótida interna: relato de caso

A recanalização espontânea tardia da carótida interna é um evento incomum e pouco estudado. Os autores relatam o caso de paciente de 73 anos, masculino, hipertenso, com antecedente de acidente vascular cerebral há 3 anos, com seqüela motora e sensitiva em membro superior direito, apresentando ao mapeamento dúplex e arteriografia oclusão total da carótida interna. Evoluiu após 2 anos com novos episódios de ataques isquêmicos transitórios de repetição. Submetido a novos exames de imagem para avaliação da circulação cerebral extra e intracraniana, evidenciou-se recanalização do vaso, com estenose severa. Foi realizada endarterectomia de carótida esquerda, sem intercorrências. Paciente evoluiu sem novos episódios após 1 mês de seguimento. Considerando a raridade do caso e a parca literatura sobre recanalização tardia de carótida, passível de reparo cirúrgico, optamos pela apresentação do caso enfocando a importância do acompanhamento de oclusões carotídeas.

Cost-effectiveness of diagnostic strategies prior to carotid endarterectomy

The main objective of this study was to assess the long-term cost-effectiveness of five alternative diagnostic strategies for identification of severe carotid stenosis in recently symptomatic patients. A decision-analytical model with Markov transition states was constructed. Data sources included a prospective study involving 167 patients who had screening Doppler ultrasound (DUS), confirmatory contrast-enhanced magnetic resonance angiography (CEMRA) and confirmatory digital subtraction angiography (DSA), individual patient data from the European Carotid Surgery Trial and other published clinical and cost data. A "selective" strategy, whereby all patients receive DUS and CEMRA (only proceeding to DSA if the CEMRA is positive and the DUS is negative), was most cost-effective. This was both the cheapest imaging and treatment strategy (35,205 dollars per patient) and yielded 6.1590 quality-adjusted life years (QALYs), higher than three alternative imaging strategies. Probabilistic sensitivity analysis demonstrated that there was less than a 10% probability that imaging with either DUS or DSA alone are cost-effective at the conventional 50,000 dollars/QALY threshold. In conclusion, DSA is not cost-effective in the routine diagnostic workup of most patients. DUS, with additional imaging in the form of CEMRA, is recommended, with a strategy of "CEMRA and selective DUS review" being shown to be the optimal imaging strategy.

Cerebral blood flow and oxygen metabolism in symptomatic internal carotid artery occlusion by atherosclerosis and by cervical dissection

Symptomatic internal carotid artery occlusion by atherosclerosis and by cervical dissection are distinct conditions with different long-term prognoses. The purpose of the present study is to investigate if regional cerebral blood flow and oxygen metabolism, after onset of stroke, differ between both conditions. Seventeen patients with symptomatic unilateral atherosclerotic internal carotid occlusion and 10 patients with symptomatic internal carotid occlusion due to cervical dissection were submitted to a positron emission tomographic (PET) study between 1 and 2 months after stroke onset. The steady state technique with 15O was used in order to determine regional cerebral blood flow, regional oxygen extraction fraction, and regional cerebral metabolic rate for oxygen in the infarct area, the peri-infarct zone, the remaining homolateral hemisphere, and the contralateral hemisphere. The results were compared between both patient's populations. The patients with cervical dissection were on average much younger than those with atherosclerotic occlusion, but neurological impairment on admission and disability at 3 months were comparable. Between both patient populations, no differences in rCBF, rOEF, and rCMRO2 could be demonstrated in the different regions of interest when the results were age-adjusted. Except for age-related changes, no differences in PET findings could be demonstrated between patients with symptomatic internal carotid occlusion caused by either atherosclerosis or cervical dissection.