Critical Internal Carotid Artery Stenosis Research Articles

Managing Vascular Surgery Emergencies and Referrals During the COVID-19 Pandemic at a Tertiary Centre in Oman.

ObjectivesThis study aimed to discuss the different challenges faced while managing emergency vascular surgery cases during the COVID-19 pandemic and how these challenges were overcome.MethodsThis study details 14 emergency cases that were managed during a period of one month from mid-March to mid-April at Sultan Qaboos University Hospital, Muscat, Oman. The cases included acute limb ischaemia, critical limb ischaemia, type B dissection of the thoracic aorta, thoraco-abdominal aneurysm, critical internal carotid artery stenosis, trauma, infected arteriovenous forearm loop graft and thrombosed arteriovenous fistulas.ResultsOnly one patient was confirmed to have COVID-19. Five were negative for COVID-19 while the remaining eight were not tested. Various strategies on how the vascular surgical team accommodated changes in hospital protocols and nationwide lockdown are discussed in detail.ConclusionsWith the judicious use of personal protective equipment and consumable surgical and endovascular devices, communication with support services and other hospitals and implementation of triage protocols, it was possible to manage vascular surgery emergencies effectively.

Role of Magnetic Resonance Spectroscopy in Evaluation of Cerebral Metabolic Status Before and After Carotid Endarterectomy/Thromboendarterectomy and Carotid Artery Stenting in Patients with Asymptomatic Critical Internal Carotid Artery Stenosis.

BackgroundThe relative efficacy of carotid endarterectomy (CEA)/thromboendarterectomy (TEA) and carotid artery stenting (CAS) already has been compared in randomized controlled trials and a meta-analysis, but only limited data exist describing the status of cerebral metabolism before and after these interventions.The aim of the present study was to compare metabolic changes before and after treatment of carotid stenosis and assess their potential clinical implications.Material/MethodsPatients with asymptomatic unilateral critical internal CAS were imaged with proton 3T magnetic resonance spectroscopy (H-MRS) because the technique is more sensitive than regular magnetic resonance imaging for detection of the early signs of ischemic events. Abnormal metabolite ratios detected with H-MRS may precede actual morphological changes associated with hypoperfusion as well as reperfusion changes. Ipsilateral and contralateral middle cerebral artery vascular territories were both evaluated before and after vascular intervention. H-MRS was performed within 24 h before and after surgery. Correlations in the metabolic data from H-MRS for N-acetylaspartic acid (NAA)+N-acetylaspartylglutamate, creatinine (Cr)+phosphocreatinine, and phosphocholine+glycerophosphocholine (Cho) were sought.ResultsH-MRS voxels from 11 subjects were analyzed. Values for dCho/CrI, dCho/CrC and Cho/Naal (P<0.001) were significantly higher ipsilaterally than contralaterally. Ratios for dNaa/ChoC and Cho/NaaC were significantly higher on the non-operated side (P<0.001).ConclusionsH-MRS may be helpful for assessment of patients with CAS, particularly because unlike other modalities, it reveals postoperative changes in metabolic brain status. Initial results indicate the important role of perioperative neuroprotective treatment.

Are systolic velocity duplex metrics negatively affected by flow aliasing in areas of critical internal carotid artery stenosis

ABSTRACTPurpose: Duplex scanning is a useful noninvasive screening tool for the detection of carotid bifurcation disease. Internal carotid artery (ICA) peak systolic velocity (PSV) and ICA/common carotid artery (CCA) PSV ratios are proven metrics determining 70%-99% ICA stenosis. A potential disadvantage of using dramatically increasing systolic velocity measurements in areas of critical arterial stenosis is flow aliasing. Diastolic velocity should be less influenced by this flow artifact. We evaluate ICA and CCA end diastolic velocity (EDV) metrics in predicting severe ICA stenosis and document the prevalence of an aliasing artifact in a population of patients with critical ICA stenosis.Methods: Consecutive patients undergoing carotid duplex assessments and contrast angiography were compared (n = 140). ICA and CCA PSV and EDV were recorded as was evidence of the flow aliasing of ICA waveforms. ICA/CCA PSV and EDV ratios were calculated. Duplex parameters were compared with angiographic ICA measurements. Receiver-operator characteristic curve (ROC) analysis was used to determine optimal criteria to identify ICA stenosis of 70% to 99%.Results: Of 256 carotid bifurcation duplex studies, critical angiographic stenosis was present in 105 arteries. Only four completed arterial duplex scans demonstrated flow aliasing. In three of these patients, systolic metrics were non-diagnostic versus ICA/CCA EDV ratios. An ICA/CCA EDV ratio of 2.3 provided the best combination of sensitivity 73.8% and specificity 75.18%.Conclusion: ICA/CCA diastolic ratios reliably determine 70% or greater ICA stenosis. Flow aliasing infrequently complicates ICA PSV.

Comorbidities and Health-Related Quality of Life Following Revascularization for Asymptomatic Critical Internal Carotid Artery Stenosis Treated with Carotid Endarterectomy or Angioplasty with Stenting.

BackgroundThis study aimed to evaluate the relationship between existing comorbidities and the effectiveness of revascularization of asymptomatic critical internal carotid artery (ICA) stenosis treated with carotid endarterectomy (CEA) or carotid artery stenting (CAS) and short-term and long-term outcome in terms of health-related quality of life (HRQoL).Material/MethodsPatients with asymptomatic critical ICA stenosis (n=62) included a group treated with CEA (n=31) and a group treated with CAS (n=31). A Health Assessment Questionnaire designed for this study was used to assess ten comorbidities, and the Short Form 36 Health Survey Questionnaire (SF-36) was used to evaluate HRQoL following CEA and CAS.ResultsThree comorbidities significantly influenced the effectiveness of revascularization in all patients studied who underwent CEA and CAS, which included symptomatic atherosclerosis in other vascular areas (p=0.048), coronary artery disease (CAD) (p=0.004), and previous myocardial infarction (MI) (p=0.004). In the CEA group, CAD and previous MI were significant comorbidities (p=0.002), when compared with the CAS group (p=0.635). In the CAS group, chronic obstructive pulmonary disease (COPD) was a significant comorbidity in terms of outcome (p=0.025).ConclusionsThe comorbidities of atherosclerotic vascular disease, CAD, and previous MI had a significant influence of the effectiveness of the revascularization and postoperative HRQoL in all patients studied with asymptomatic critical ICA stenosis who were treated with CEA and CAS. When the two groups were compared, CAD and previous MI were significant comorbidities in the CEA group, and COPD was a significant comorbidity in the CAS group.

Clinical features and the degree of cerebrovascular stenosis in different types and subtypes of cerebral watershed infarction

BackgroundWhether there are differences in pathogenesis among different types and subtypes of cerebral watershed infarction (WSI) is controversial since they have been combined into a single group in most previous studies.MethodsWe prospectively identified 340 supratentorial WSI patients at Beijing Chao-Yang Hospital, Capital Medical University, China and classified them based on diffusion-weighted imaging(DWI) templates. Baseline characteristics, clinical courses and neuroradiological features were compared among patients with different types and subtypes of WSI.ResultsWe identified 92 patients with cortical watershed infarction (CWI), 112 with internal watershed infarction (IWI) and 136 with mixed-type infarction. Compared with CWI patients, more IWI patients had critical stenosis of internal carotid artery (ICA) (P < 0.001). For the CWI group, patients with anterior watershed infarction (AWI) were more prone to critical ICA stenosis than those with posterior watershed infarction (PWI) (P = 0.011). For the IWI group, critical ICA stenosis was more prevalent in patients with partial IWI (P-IWI) than in those with confluent IWI (C-IWI) (P = 0.026). IWI patients were more frequently found to have clinical deterioration during the first 7 days of hospitalization and a poor prognosis at the 90th day than in CWI patients (P = 0.003 and P = 0.014, respectively).ConclusionsIWI, especially the P-IWI subtype, is associated with hemodynamic impairment (HDI), whereas CWI has a weaker correlation with ICA steno-occlusion. Furthermore, IWI patients are more prone to poor prognosis.

Double or nothing: red flag symptoms of critical carotid stenosis, a case report

BackgroundDetailed knowledge of every possible manifestation of Internal Carotid Artery (ICA) disease is important. For improving detection and a timely adoption of secondary prevention procedures or treatments. Transient oculomotor nerve palsies have been described associated with stenosis or occlusion of the ICA.Case presentationWe described a patient that develop a sequential combination of transient monocular loss of vision followed by binocular diplopia secondary to an unstable atherosclerotic preocclusive stenosis of an internal carotid artery previously treated with radiotherapy.ConclusionsThe peculiar sequence of transient monocular vision that give rise later into a transient binocular diplopia (double or nothing) should be kept in mind as a possible manifestation of critical stenosis of ICA.

Heads Up! A Novel Provocative Maneuver to Guide Acute Ischemic Stroke Management

Background: A common dilemma in acute ischemic stroke management is whether to pursue recanalization therapy in patients with large vessel occlusions but minimal neurologic deficits. We describe and report preliminary experience with a provocative maneuver, i.e. 90-degree elevation of the head of bed for 30 min, which stresses collaterals and facilitates decision-making. Methods: A prospective cohort study of <7.5 h of acute anterior circulation territory ischemia patients with minimal deficits despite middle cerebral artery (MCA) or internal carotid artery (ICA) occlusive disease. Results: Five patients met the study entry criteria. Their mean age was 78.4 years (range 65-93). All presented with substantial deficits (median NIHSS score 11, range 5-22), but improved while in supine position during initial imaging to normal or near-normal (NIHSS score 0-2). MRA showed persistent M1 MCA occlusions in 4, critical ICA stenosis or occlusion in 1, and substantial perfusion-diffusion mismatch in all. To evaluate the potential for eventual collateral failure, patients were placed in a head of bed upright posture. Mean arterial pressure and heart rate were unchanged. Two showed no neurologic worsening and were treated with supportive care with excellent final outcome. Three showed worsening, including recurrent hemiparesis and aphasia at the 6th, recurrent aphasia at the 23rd, and recurrent hemineglect at the 15th upright minute. These 3 underwent endovascular recanalization therapies with successful reperfusion and excellent final outcome. Conclusion: The ‘Heads Up' test may be a useful, simple maneuver to assess the risk of collateral failure and guide the decision to pursue recanalization therapy in acute cerebral ischemia patients with minimal deficits despite persisting large cerebral artery occlusion.

Flow Reversal for Proximal Neuroprotection During Endovascular Management of Critical Symptomatic Carotid Artery Stenosis Coexisting With Ipsilateral External Carotid Artery Occlusion

To report the utility of proximal brain protection by flow reversal in endovascular management of critical internal carotid artery (ICA) stenosis coexisting with ipsilateral external carotid artery (iECA) occlusion. Four patients with a symptomatic, critical ICA stenosis (in-stent restenosis in one) and iECA occlusion were admitted for carotid artery stenting (CAS). In all cases, the stenosis severity and high-risk lesion morphology precluded the use of filter protection. The "tailored" CAS algorithm indicated that a proximal anti-embolism system should be used to maximize the potential for effective neuroprotection. The flow reversal system, which consists of an independent guiding sheath balloon positioned in the common carotid artery (CCA) and an iECA balloon-wire, was employed, using the CCA balloon only. The system was well-tolerated, and the CAS procedures were uneventful. Due to a unique design with separate CCA and iECA balloons, the flow reversal system can be used for proximal neuroprotection during CAS in severe, symptomatic ICA lesions coexisting with iECA occlusion.

Cerebrovascular response time to a breath-holding challenge

To evaluate the timecourse of cerebrovascular reserve response to breath-holding. Using simultaneous bilateral transcranial Doppler (TCD) recordings from the MCA during a breath-holding challenge, we measured the time interval between baseline and peak blood flow velocity values in 25 patients with critical unilateral internal carotid artery (ICA) stenosis (> 85% lumen diameter reduction), in 9 patients with a non-critical (70-85%) ICA-stenosis and in 27 normal controls. Normal controls and patients with non-critical stenosis reached peak MCA velocities on both sides almost simultaneously. For the patients with critical stenosis the peak response time ipsilateral to the stenosis was delayed 2.40 +/- 3.43 sec compared to the opposite side. This delay resolved after carotid endarterectomy. In response to a breath-holding challenge unilateral critical ICA stenosis is associated with a significant ipsilateral prolongation of the rise time from baseline to peak MCA velocity.

Potential Role for TCD-Directed Antiplatelet Agents in Symptomatic Carotid Artery Dissection

HomeStrokeVol. 37, No. 3Potential Role for TCD-Directed Antiplatelet Agents in Symptomatic Carotid Artery Dissection Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBPotential Role for TCD-Directed Antiplatelet Agents in Symptomatic Carotid Artery Dissection Christopher H.E. Imray Kyle T.S. Pattinson Christopher H.E. ImrayChristopher H.E. Imray Coventry and Warwickshire County Vascular Unit, Coventry and Warwickshire University Hospitals, Coventry, UK Search for more papers by this author Kyle T.S. PattinsonKyle T.S. Pattinson Nuffield Department of Anaesthetics, University of Oxford, The John Radcliffe Hospital, Oxford, UK Search for more papers by this author Originally published1 Mar 2006https://doi.org/10.1161/01.STR.0000204060.73207.c5Stroke. 2006;37:767To the Editor:We read with interest the debate regarding the role of anticoagulation in extracranial arterial dissection.1–3 We agree with Norris1 that artery to artery embolism is the most likely cause of stroke, and also agree with Lyrer2 that there is no evidence supporting anticoagulation for extracranial internal carotid artery dissection (CAD). Donnan and Davis3 make a most important contribution when they differentiate between the use of antithrombotic agents and antiplatelet agents in CAD.The commonest mechanism of stroke in carotid artery dissection is hypothesized to be artery to artery embolism.1 If this hypothesis is correct, then the situation would appear to be analogous to transient ischemic attacks arising from a critical internal carotid artery stenosis. Transcranial Doppler (TCD)-directed intravenous antiplatelet agents have been successful in treating these patients4,5,6 both before and after elective surgery. In further support of this hypothesis, we have recently reported a 45-year-old patient who was successfully treated with TCD-directed antiplatelet agents7 for recurrent focal deficits associated with an embolizing subintimal CAD.Converging lines of evidence suggest that embolization from large arteries can cause focal cerebral symptoms and can be treated in the short-term with TCD-directed antiplatelet agents.4 TCD can rapidly and noninvasively assist both in identifying those patients at higher risk of a subsequent neurological event,8 and in assessing the efficacy of interventions.5 TCD emboli detection appears to offer an important advance, enabling the optimal integration of both medical therapy and the timing of any surgical intervention, in patients with symptomatic large-vessel disease. We advocate TCD interrogation of the middle cerebral artery for microemboli in symptomatic CAD, particularly where there are fluctuating neurological signs. TCD-directed antiplatelet agents could then be used to control cerebral microemboli and symptoms.7 Elective surgical or endovascular intervention can then be considered where appropriate.1 Norris JW. Extracranial arterial dissection: anticoagulation is the treatment of choice: For. Stroke. 2005; 36: 2041–2042.LinkGoogle Scholar2 Lyrer PA. Extracranial arterial dissection: anticoagulation is the treatment of choice: Against. Stroke. 2005; 36: 2042–2043.LinkGoogle Scholar3 Donnan GA, Davis SM. Extracranial arterial dissection: anticoagulation is the treatment of choice. Stroke. 2005; 36: 2043–2044.LinkGoogle Scholar4 Lennard NS, Vijayasekar C, Tiivas C, Chan CWM, Higman DJ, Imray CHE. Control of emboli in patients with recurrent or crescendo transient ischaemic attacks using preoperative transcranial Doppler-directed Dextran therapy. Br J Surg. 2003; 90: 166–170.CrossrefMedlineGoogle Scholar5 Imray CHE, Tiivas CAS. Are some strokes preventable? The potential role of transcranial Doppler in transient ischaemic attacks of carotid origin. Lancet Neurol. 2005; 4: 580–586.CrossrefMedlineGoogle Scholar6 Naylor AR, Hayes PD, Allroggen H, Lennard N, Gaunt ME, Thompson MM, London NJ, Bell PR. Reducing the risk of carotid surgery: a 7-year audit of the role of monitoring and quality control assessment. J Vasc Surg. 2000; 32: 750–759.CrossrefMedlineGoogle Scholar7 Joseph T, Kandiyil N, Beale D, Tiivas C, Imray CHE. A novel treatment for symptomatic carotid dissection. Postgraduate Med J. 2005; 81: e6.CrossrefMedlineGoogle Scholar8 Markus HS, MacKinnon A. Asymptomatic embolization detected by Doppler ultrasound predicts stroke risk in symptomatic carotid artery stenosis. Stroke. 2005; 36: 971–975.LinkGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By SADAHIRO H, ISHIHARA H, YONEDA H, KATO S, YOSHINO H, IMOTO H, SHINOYAMA M, MAEDA Y, OKA F and SUZUKI M (2010) TCD-directed therapy for cervical internal carotid artery dissection : two case reports, Neurosonology, 10.2301/neurosonology.23.9, 23:1, (9-12), . Peairs N and Stillings J (2020) Carotid Artery Dissection as a Result of Penetrating Ear Trauma, Clinical Practice and Cases in Emergency Medicine, 10.5811/cpcem.2020.6.47537, 4:3, (489-490) March 2006Vol 37, Issue 3 Advertisement Article InformationMetrics https://doi.org/10.1161/01.STR.0000204060.73207.c5PMID: 16505347 Originally publishedMarch 1, 2006 PDF download Advertisement

５．脳梗塞超急性期の主幹動脈病変に対する外科的治療―特に頚動脈内膜切除術の意義と限界―

In this report, I reviewed lireratures and our clinical experiences of surgical revascularization ; carotid endarterectomy (CEA), intracranial embolectomy, and EC-IC bypass on emergency basis after ischemic cerebral stroke. Especially, in the cases with symptomatic and critical stenosis/complete occlusion of the internal carotid artery (ICA), current topics about efficacy and treatment algolism of emergency or ultra-emergency CEA in this clinical category. In summary ; 1) Crescendo TIAs and stroke in evolution are characteristic symptoms of the critical ICA stenosis and these cases will be absolute indication for emergency CEA. Significance of these symptoms should be more emphasized for early diagnosis in this clinical category. 2) Ultra-emergency thrombolysis and CEA should be the only successful procedure in the serious ICA occlusion group. Proper and quick examination system for true diagnosis, especially for evaluation of effectiveness and risk of surgical revascularization, must be considered.

Reversible Abnormalities in the Ophthalmic Arteries Detected by Color Doppler Imaging

To demonstrate dynamic, reversible abnormalities in ophthalmic artery blood flow velocity identified with color Doppler imaging (CDI) in patients with clinical findings of ocular ischemia with and without carotid artery stenosis. One patient with ocular ischemia and normal carotid arteries had abnormal ophthalmic artery velocities demonstrated by CDI. Two other patients with reversed ophthalmic artery flow and critical internal carotid artery stenosis were studied before and after carotid endarterectomy. Peak systolic and diastolic velocities as well as pulsatility indices of ophthalmic, posterior ciliary, and central retinal arteries were calculated. The patient who had ocular ischemic syndrome without carotid artery stenosis showed increased ophthalmic artery velocities initially, and reversal of flow within the ophthalmic artery subsequently developed. Clinical findings and symptoms improved gradually as ophthalmic artery, posterior ciliary, and central retinal artery velocities increased. The patients with critical internal carotid artery stenosis had reversed ophthalmic artery blood flow initially which reverted to normal after carotid endarterectomy. Ocular ischemic syndrome may occur due to abnormal blood flow in the ophthalmic artery in the absence as well as in the presence of carotid artery stenosis. Flow dynamics in the ophthalmic artery and its branches can be shown by CDI to revert toward normal as the clinical findings improve spontaneously or after opening an occluded carotid artery.