Symptomatic Carotid Occlusion Research Articles

Urgent endarterectomy for symptomatic carotid occlusion is associated with a high mortality

ObjectiveInterventions for carotid occlusions undertaken are undertaken and the outcomes are poorly defined. We sought to study patients undergoing urgent carotid revascularization for symptomatic occlusions. MethodsThe Society for Vascular Surgery Vascular Quality Initiative database was queried from 2003 to 2020 to identify patients with carotid occlusions undergoing carotid endarterectomy. Only symptomatic patients undergoing urgent interventions within 24 hours of presentation were included. Patients were identified based on computed tomography and magnetic resonance imaging. This cohort was compared with symptomatic patients undergoing urgent intervention for severe stenosis (≥80%). The primary end points were perioperative stroke, death, myocardial infarction (MI) and composite outcomes as defined by the Society for Vascular Surgery reporting guidelines. Patient characteristics were analyzed to determine predictors of perioperative mortality and neurological events. ResultsWe identified 390 patients who underwent urgent CEA for symptomatic occlusions. The mean age was 67.4 ± 10.2 years (range, 39-90 years). The cohort was predominantly male (60%) with associated risk factors for cerebrovascular disease, including hypertension (87.4%), diabetes (34.4%), coronary artery disease (21.6%), and current smoking (38.7%). This population had high use of medications, including statins (78.6%), P2Y12 inhibitors (32.0%), aspirin (77.9%), and renin-angiotensin inhibitors (43.7%) preoperatively. When compared with patients undergoing urgent endarterectomy for severe stenosis (≥80%), those with symptomatic occlusion were well-matched with regard to risk factors, but the severe stenosis cohort seemed to be managed better medically and less likely to present with cortical stroke symptoms. Perioperative outcomes were significantly worse for the carotid occlusion cohort, primarily driven by higher perioperative mortality (2.8% vs 0.9%; P < .001). The composite end point of stroke/death/MI was also significantly worse in the occlusion cohort (7.7% vs 4.9%; P = .014). On multivariate analysis, carotid occlusion was associated with increased mortality (odds ratio, 3.028; 95% confidence interval, 1.362-6.730; P = .007) and composite outcome of stroke, death, or MI (odds ratio, 1.790; 95% confidence interval, 1.135-2.822; P = .012). ConclusionsRevascularization for symptomatic carotid occlusion constitutes approximately 2% of carotid interventions captured in the Vascular Quality Initiative, affirming the rarity of this undertaking. These patients have acceptable rates of perioperative neurological events, but are at an elevated risk of overall perioperative adverse events, primarily driven by higher mortality, compared with those with severe stenosis. Carotid occlusion seems to be the most significant risk factor for the composite end point of perioperative stroke, death, or MI. Although intervention for a symptomatic carotid occlusion may be performed with acceptable rate of perioperative complications, judicious patient selection is warranted in this high-risk cohort.

Cerebral autoregulation and blood flow distribution in the precerebral arteries for determining indications of extra-intracranial bypass in patients with carotid artery occlusion

Background. Prevention of ischemic stroke in patients with carotid artery occlusion is conventionally associated with performing cerebral revascularization. However, determining the indications for it is still an actual problem. The informative value of noninvasive assessment of cerebral autoregulation and blood flow distribution in the precerebral arteries in patients with carotid artery stenosis is shown. At the same time, in patients with carotid artery occlusion, these indicators have been studied to a lesser extent.Aim. To evaluate the informative value of cerebral autoregulation and blood flow distribution in the precerebral arte ries for determination the indications of extra‑intracranial bypass in patients with carotid occlusion.Materials and methods. 54 patients (aged from 41 to 83 y. o.) with carotid artery occlusion were studied. Blood flow velocity in intracranial arteries was determined with transcranial Doppler (system Multi‑Dop X), whereas flow velocity index in precerebral arteries – with duplex scanning (system Vivid Е). Cerebral autoregulation was assessed based on phase shift between spontaneous oscillations of blood flow velocity in basal cerebral arteries and systemic blood pressure within the range of Mayer’s waves (80–120 mHz).Results. The state of cerebral autoregulation was imparied on both sides in 90 % patients with the symptomatic carotid occlusion (0.3 ± 0.3 rad ipsilateral, 0.7 ± 0.6 rad contralateral). The state of cerebral autoregulation was not impaired in 79 % patients with asymptomatic carotid occlusion (1.0 ± 0.3 rad ipsilateral, 1.1 ± 0.4 rad contralateral). The flow velocity index in the contralateral internal carotid artery (306 ± 109 ml / min) and the ipsilateral vertebral (139 ± 69 ml / min) and external carotid (175 ± 72 ml / min) arteries was increased.Conclusions. Noninvasive preoperative assessment of cerebral autoregulation and blood flow distribution in the precerebral arteries makes to evaluate the state of the cerebrovascular reserve to quantify and can be used to determining indications for cerebral revascularization in patients with carotid occlusion.

Urgent Endarterectomy for Symptomatic Carotid Occlusion Is Associated With a High Mortality

Urgent Endarterectomy for Symptomatic Carotid Occlusion Is Associated With a High Mortality

Symptomatic and Asymptomatic Chronic Carotid Artery Occlusion on High-Resolution MR Vessel Wall Imaging.

Chronic carotid artery occlusion remains a poorly understood risk factor for subsequent stroke, and potential revascularization is dependent on understanding the anatomy and nature of the occlusion. Luminal imaging cannot assess the nature of an occlusion, so the internal structure of the occlusion must be inferred. The present study examines the signal characteristics of symptomatic and asymptomatic carotid occlusion that may point to management differentiation. We prospectively recruited patients who were diagnosed with chronic carotid artery occlusion defined as longer than 4 weeks and confirmed by DSA. All patients underwent high-resolution MR vessel wall imaging examinations after enrollment. Baseline characteristics, vessel wall imaging features, and DSA features were collected and evaluated. The vessel wall imaging features included segment involvement, signal intensity, contrast enhancement, and vessel wall thickness. The symptomatic and asymptomatic chronic carotid artery occlusions were compared. A total of 44 patients with 48 lesions were included in this study from February 2020 to December 2020. Of the 48 lesions, 35 (72.9%) were symptomatic and 13 (27.1%) were asymptomatic. There was no difference in baseline and DSA features. On vessel wall imaging, C1 and C2 were the most commonly involved segments (91.7% and 68.8%, respectively). Compared with symptomatic lesions, asymptomatic lesions were more often isointense (69.2%) in the distal segment (P = .03). Both groups had diffuse wall thickening (80% and 100%). Signal characteristics between those with symptomatic and asymptomatic carotid artery occlusions differ in a statistically significant fashion, indicating a different structure of the occlusion.

Temporary application of lower body positive pressure improves intracranial velocities in symptomatic acute carotid occlusion or tight stenosis: A pilot study

Patients with isolated cervical carotid artery occlusion not eligible to recanalization therapies but with compromised intracranial hemodynamics may be at risk of further clinical events. Apart from lying flat until spontaneous recanalization or adjustment of the collateral circulation hopefully occurs, no specific treatment is currently implemented. Improving collateral flow is an attractive option in this setting. Lower body positive pressure (LBPP) is known to result in rapid venous blood shift from the lower to the upper body part, in turn improving cardiac preload and output, and is routinely used in acute hemorrhagic shock. We report here cerebral blood flow velocities measured during LBPP in this patient population. This is a retrospective analysis of the clinical, physiological, and transcranial Doppler monitoring data collected during and 15 min after LBPP in 21 consecutive patients (10 females, median age: 54 years) with recently symptomatic isolated carotid occlusion/tight stenosis (unilateral in 18) mostly due to atherosclerosis or dissection. LBPP was applied for 90 min at a median 5 days after symptom onset. At baseline, middle-cerebral artery velocities were markedly lower on the symptomatic, as compared to asymptomatic, side. LBPP significantly improved blood flow velocities in both the symptomatic and asymptomatic middle-cerebral artery as well as the basilar artery, which persisted 15 min after discontinuing the procedure. LBPP also resulted in mild but significant increases in mean arterial blood pressure. LBPP improved intracranial hemodynamics downstream recently symptomatic carotid occlusion/tight stenosis as well as in the contralateral and posterior circulations, which persisted after LBPP deflation. Randomized trials should determine if this easy-to-use, noninvasive, nonpharmacologic approach has long-lasting benefits on the intracranial circulation and improves functional outcome.

Safety and efficacy of symptomatic carotid artery stenting performed in an emergency setting.

Carotid artery stenting (CAS) has increasingly emerged as an alternative strategy to carotid endarterectomy in the treatment of patients with symptomatic carotid stenosis. Optimal timing for CAS after symptoms onset remains unclear. We aimed to evaluate the safety and efficacy of CAS when performed in an emergency setting. We performed a retrospective analysis of CAS patients admitted to our CSC with symptomatic extracranial carotid occlusion or significant stenosis from January 2014-September 2019. Emergency CAS was defined as CAS performed during the same hospitalization from TIA/stroke onset, whereas elective CAS as CAS performed on a subsequent admission. The primary outcome was defined as the occurrence of any stroke, myocardial infarction, or death related to the procedure at 3 months of follow-up. Secondary outcomes included periprocedural complications and the rate of restenosis/occlusion at follow-up. Logistic regression and survival analyses were used to compare outcomes and restenosis at follow-up. We identified 75 emergency and 104 elective CAS patients. Emergency CAS patients had significantly higher rates of ipsilateral carotid occlusion (17% vs. 2%, p < 0.001) and use of general anesthesia (19% vs. 4%, p = 0.001) than elective CAS. There were no significant differences between emergency and elective CAS in the primary (5.7% vs. 1%, p = 0.161) and secondary (9% vs. 4.8%, p = 0.232) outcomes. We did not find differences in the rate of restenosis/occlusion (7% vs. 11.6%; log-rank test p = 0.3) at a median of 13 months follow-up. In our study, emergency CAS in symptomatic patients might have a similar safety and efficacy profile to elective CAS at 3 months and long-term follow-up.

Assessment of Intracranial Collateral Circulation Using Novel TCCS Grading System in Patients With Symptomatic Carotid Occlusion.

Objectives: To establish a novel transcranial color-coded sonography (TCCS) grading system for collateral circulation in cases of symptomatic chronic total carotid occlusion (TCO), and to correlate this new grading system with cerebrovascular reserve capacity (CVR) measured by SPECT.Methods: Thirty-four patients with symptomatic chronic TCO recruited from the neurovascular ultrasound laboratory of the department of Neurology at Cairo University Hospital during 3 years' time period and diagnosed by color-coded duplex were subjected to: clinical assessment, grading of cerebral collaterals using a proposed TCCS criteria, Brain SPECT studies at rest and with dipyridamole stress.Results: The new grading system for cerebral collateral circulation showed a significant positive correlation with CVR (P < 0.001 and Spearman correlation coefficient 0.686).Conclusion: The current study showed that this new TCCS grading system for cerebral collaterals is a reliable indicator for cerebral perfusion and reserve capacity in cases of chronic symptomatic TCO.

Multi-dimensional Evaluation System for Recanalization of Symptomatic Non-acute Carotid Artery Occlusion

Multi-dimensional Evaluation System for Recanalization of Symptomatic Non-acute Carotid Artery Occlusion

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 62.3years, 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.

Local Cerebral Hemodynamics after Superficial Temporal Artery-Middle Cerebral Artery Bypass in Patients with Symptomatic Carotid Occlusions.

Context:Physiological insights into blood flow alterations in cortical vessels after superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery are important for the prognosis of bypass sustainability and hemodynamic patency.Aims:This study aims to assess the impact of STA-MCA bypass on local hemodynamics for patients with symptomatic carotid occlusions and Moyamoya disease.Settings and Design:This article presents a prospective nonrandomized study of intraoperative blood flow measurements in cortical branches of MCA and donor vessel before and after cerebral revascularization.Materials and Methods:Evaluation of local hemodynamic parameters was established for 112 patients with symptomatic carotid occlusive disease and cerebrovascular insufficiency during STA-MCA bypass surgery. We used intraoperative Doppler ultrasonography (89 patients – 72%), flowmetry (56 cases – 50%), and in 33 cases both methods. For physical justification of observed facts, we performed computational simulation with OpenFOAM CFD framework using Navier-Stokes nonstationary hemodynamic model.Statistical Analysis Used:All calculations were performed with IBM SPSS Statistics version 10.0 software. We used parametric (Z-test and Student's t-test) and nonparametric models (Wilcoxon, Mann–Whitney). For categorical values, we used Fisher's exact test.Results:Local cerebral hemodynamics after revascularization surgery significantly depended on initial perfusion deficit and the ability of bypass to reverse the blood flow in proximal parts of cortical artery (86 cases, 77%). Mechanism of cortical blood flow alteration was related to donor vessel cut flow value and potential consumption threshold of acceptor artery.Conclusions:Knowledge of hemodynamic principles of flow redistribution after STA-MCA bypass is important to improve bypass stainability and leads to better revascularization results.

Cognition and Quality of Life in Symptomatic Carotid Occlusion

Purpose: Carotid occlusion may result in stroke, TIA, and cognitive reductions. Whether cognition predicts quality of life (QOL) for patients with carotid occlusion is unknown. Depression is also known to affect QOL. We examined whether cognition and depression predicted QOL in patients with carotid occlusive disease who have not had revascularization.Methods: Patients with unilateral carotid occlusion and history of TIA or a remote history of minor stroke were included. Patients underwent exam of memory, language, motor, and executive function skills and completed depression and QOL questionnaires (Center for Epidemiological Studies-Depression [CES-D], Stroke Specific QOL [SSQOL]). Deficits from remote stroke were assessed with the NIH Stroke Scale (NIHSS). Z-scores for cognitive tests were averaged (Cog-Z). The SSQOL scores were averaged across subgroup domains. Analyses of patients with all depression levels were followed by subgroup analyses for patients with minimal depression. Correlation findings were used to select the variables in a regression model to predict SSQOL.Results: Among 37 patients with all depression levels, QOL was predicted by deficits from remote stroke and depression (F(3, 36) = 21.15, P<.0005; NIHSS Beta = –.392, P = .001; CES-D Beta = –.577, P < .0005). Among 22 patients with minimal depression, QOL was predicted by cognitive and depression scores, (F(2,21) = 7.88, P = .003; Cog-Z Beta = .364, P = .05; CES-D Beta = –.495, P = .01).Conclusions: In patients with carotid occlusive disease without major stroke and without revascularization, cognitive and depression scores independently predicted QOL. These data demonstrate the clinical relevance of cognitive and mood decline among patients with carotid occlusion.

Blood Flow Lateralization and Collateral Compensatory Mechanisms in Patients With Carotid Artery Stenosis.

Background and Purpose—Four-dimensional phase-contrast magnetic resonance imaging enables quantification of blood flow rate (BFR; mL/min) in multiple cerebral arteries simultaneously, making it a promising technique for hemodynamic investigation in patients with stroke. The aim of this study was to quantify the hemodynamic disturbance and the compensatory pattern of collateral flow in patients with symptomatic carotid stenosis.Methods—Thirty-eight patients (mean, 72 years; 27 men) with symptomatic carotid stenosis (≥50%) or occlusion were investigated using 4-dimensional phase-contrast magnetic resonance imaging. For each patient, BFR was measured in 19 arteries/locations. The ipsilateral side to the symptomatic carotid stenosis was compared with the contralateral side.Results—Internal carotid artery BFR was lower on the ipsilateral side (134±87 versus 261±95 mL/min; P<0.001). BFR in anterior cerebral artery (A1 segment) was lower on ipsilateral side (35±58 versus 119±72 mL/min; P<0.001). Anterior cerebral artery territory bilaterally was primarily supplied by contralateral internal carotid artery. The ipsilateral internal carotid artery mainly supplied the ipsilateral middle cerebral artery (MCA) territory. MCA was also supplied by a reversed BFR found in the ophthalmic and the posterior communicating artery routes on the ipsilateral side (−5±28 versus 10±28 mL/min, P=0.001, and −2±12 versus 6±6 mL/min, P=0.03, respectively). Despite these compensations, BFR in MCA was lower on the ipsilateral side, and this laterality was more pronounced in patients with severe carotid stenosis (≥70%). Although comparing ipsilateral MCA BFR between stenosis groups (<70% and ≥70%), there was no difference (P=0.95).Conclusions—With a novel approach using 4-dimensional phase-contrast magnetic resonance imaging, we could simultaneously quantify and rank the importance of collateral routes in patients with carotid stenosis. An important observation was that contralateral internal carotid artery mainly secured the bilateral anterior cerebral artery territory. Because of the collateral recruitment, compromised BFR in MCA is not necessarily related to the degree of carotid stenosis. These findings highlight the importance of simultaneous investigation of the hemodynamics of the entire cerebral arterial tree.

A Modified Encephalo-Duro-Synangiosis Technique Induced Neovascularization in Symptomatic Atherosclerotic Carotid Artery Occlusion: A Phase I trial

To the best of our knowledge, the present study is the first to assess the safety and feasibility of a modified encephalo-galeo-duro-synangiosis operation in patients with atherosclerotic carotid artery occlusion. Eight patients who had experienced new ipsilateral cerebrovascular events after the diagnosis of carotid artery occlusion were recruited. To facilitate extracranial-to-intracranial collateralization, 5 or 6 burr holes were made, and the dura mater and arachnoid were opened. The patients were closely monitored for complications and underwent conventional angiography, magnetic resonance imaging, and perfusion-weighted magnetic resonance imaging at baseline and 1 year of follow-up. After 10 years, the patients who were still alive were interviewed and assessed for functional outcomes and neurological status. No surgery-related adverse events were observed, apart from temporary headache and subcutaneous effusion. Four of six patients had developed an extracranial-to-intracranial collateral blood vessels on angiography, and these patients had no incident ischemic events during the follow-up period. During the long-term follow-up period (10 years), 3 patients had died. Of those living, 4 of the 5 patients reported total resolution of the symptoms, with no incident ischemic events. One patient still experienced disability from an ischemic stroke that occurred as a result of the 1-year follow-up angiography. Encephalo-duro-galeo-synangiosis for symptomatic carotid occlusion seems to be safe and feasible and might be able to induce extracranial-to-intracranial collaterals in patients with carotid artery occlusion. Further studies are needed to define the optimal therapeutic window and yield of burr hole surgery in the treatment of symptomatic carotid occlusive disease as an adjuvant to extracranial-intracranial bypass.

Local cerebral hemodynamics following STA-MCA bypass in patients with symptomatic carotid occlusions

To assess changes in local hemodynamic parameters in patients with symptomatic ICA occlusions and moyamoya disease after placement of extracranial-intracranial bypass (EC-IC bypass). The study included 112 patients who underwent surgical treatment at the National Scientific and Practical Center for Neurosurgery in the period between 1999 and 2015. Of these, 105 patients had ICA occlusions, and 7 patients had moyamoya disease. During the main stage of EC-IC bypass placement, all patients were monitored for local hemodynamic parameters using intraoperative contact Doppler ultrasonography - 89 (72%) patients (72%) and flowmetry - 56 (50%)). In 33 (29%) cases, both techniques were used. Forty two patients underwent preoperative SCT perfusion to assess the degree of perfusion deficit. Grade 1 cerebrovascular insufficiency (acute oligemia) was detected in 6 patients; grade 2 perfusion deficit (persistent oligemia) was found in 25 patients; grade 3 perfusion deficit (chronic oligemia) was present in 11 patients. Measurements were performed before bypass placement: the blood flow direction and hemodynamic parameters in the cortical arteries were evaluated; and after bypass placement: blood flow values and directions in the cortical artery, proximal and distal to the bypass area, were assessed. A total of 112 EC-IC bypasses were placed without perioperative complications and deaths. Bypass functioning was confirmed in 108 (96.3%) cases; bypass thrombosis occurred in 4 (3.7%) cases. The distal blood flow direction was observed in patients with ICA occlusions (105 patients) in all cases before EC-IC bypass placement. Patients with moyamoya disease had more often the proximal blood flow direction - 5 (71%) out of 7 cases. The cerebral blood flow parameters obtained in this study differed significantly, depending on the baseline degree of perfusion deficit. The blood flow rate was minimal in patients with grade 1 cerebrovascular insufficiency. After revascularization, local hemodynamics in the cortical arteries was significantly dependent on the ability of EC-IC bypass to reverse blood flow in the proximal acceptor artery. A change in the blood flow direction was observed in 86 (77%) cases. The mean volumetric blood flow in EC-IC bypass was 34.2±5.7 mL/min. The knowledge of baseline hemodynamic parameters and their changes after revascularization plays an important role in choosing the correct surgical technique, further bypass functioning, and, as a result, improvement of the clinical outcome after surgery.

Predictors of poor cerebral collaterals and cerebrovascular reserve in patients with chronic total carotid occlusion

Background: This study aims to investigate the relationship between cerebrovascular reserve (CVR) capacity, as measured by single-photon emission computed tomography (SPECT) and collateral blood flow, according to a transcranial colour-coded duplex(TCCD), in patients with symptomatic total carotid occlusion (TCO). Additionally, the study aims to determine whether vascular risk factors have an effect on collateral blood flow, as well as on the CVR.Methods: Thirty-four patients with chronic TCO, diagnosed by carotid duplex scanning and confirmed by other vascular imaging modalities, who had ischaemic symptoms either as stroke or transient ischaemic attack, were subjected to clinical assessment, SPECT under dipyridamole stress, and grading of cerebral collateral blood flow using TCCD. Demographics and vascular risk factors were correlated with SPECT and TCCD findings.Results: CVR showed a significant positive correlation with the intensity of collaterals with P value <0.001 and a Spearman correlation coefficient of 0.686. Hypertension was the only predictor of poor collaterals (p value =0.049; OR =11.5 with 95% CI 1.01–131.16).Smoking was predictive of poor CVR as measured by qualitative SPECT (p value =0.02; OR =13.2 with 95% CI 1.4–120.6).Conclusion: Cerebral collaterals have an important role in the maintenance of CVR in patients with TCO. Preventive measures should be directed towards hypertension and smoking to preserve cerebral collateral patency and consequently improve CVR in patients with TCO.

Bilateral persistent primitive hypoglossal arteries associated with unilateral symptomatic carotid occlusion (P1.298)

Bilateral persistent primitive hypoglossal arteries associated with unilateral symptomatic carotid occlusion (P1.298)

Assessment of ‘on-treatment platelet reactivity’ and relationship with cerebral micro-embolic signals in asymptomatic and symptomatic carotid stenosis

IntroductionThe relationship between on-treatment platelet reactivity and cerebral micro-embolic signals (MES) is unknown, and has not been previously simultaneously assessed in asymptomatic and symptomatic carotid stenosis patients. MethodsConsecutive eligible patients with ≥50% asymptomatic or recently symptomatic carotid stenosis (≤4weeks following TIA/ischaemic stroke) were recruited to this pilot study. Symptomatic patients were followed up to the ‘late’ phase (≥3months) following symptom onset or carotid intervention; longitudinal data were analysed from symptomatic patients with data available at both time-points. Platelet function/reactivity was assessed with the PFA-100® to measure collagen-ADP (C-ADP) and collagen-epinephrine (C-EPI) closure times in citrate-anticoagulated whole blood. Bilateral simultaneous 1-hour transcranial Doppler ultrasound (TCD) monitoring of the middle cerebral arteries was performed to classify patients as MES +ve or MES −ve. Results31 patients with ≥50% asymptomatic and 46 with early symptomatic carotid stenosis or occlusion were included. 35 symptomatic patients were followed up to the late phase (23 following carotid intervention). Prevalence of ‘high on-treatment platelet reactivity’ (HTPR) on the C-EPI cartridge did not differ between asymptomatic and symptomatic patients overall, but was lower in ‘symptomatic post-intervention’ than asymptomatic patients on aspirin monotherapy (10% vs. 50%; p=0.03). The prevalence of HTPR on the C-EPI cartridge decreased between the early and late phases in symptomatic patients (63% vs. 34%; p=0.017), including those on aspirin monotherapy (p=0.016). There were no significant differences in HTPR status between asymptomatic vs. early or late symptomatic MES +ve or MES −ve patients. DiscussionCarotid interventional treatment, presumably in combination with resolution of the acute phase response, may decrease the prevalence of HTPR in patients with recently symptomatic carotid stenosis over time. Preliminary subgroup analysis suggests that successful intervention may reduce the prevalence of aspirin-HTPR in symptomatic patients to lower levels than asymptomatic medically-treated patients on aspirin monotherapy. Larger, longitudinal studies are warranted to reassess the impact of more intensive secondary preventive treatment on ex vivo platelet function at different levels of shear stress in carotid stenosis patients.

Symptomatic Carotid Occlusion Is Frequently Associated With Microembolization.

Symptomatic carotid artery disease is associated with significant morbidity and mortality. The pathophysiologic mechanisms of cerebral ischemia among patients with carotid occlusion remain underexplored. We conducted a prospective observational cohort study of patients hospitalized within 7 days of ischemic stroke or transient ischemic attack because of ≥50% carotid artery stenosis or occlusion. Transcranial Doppler emboli detection was performed in the middle cerebral artery ipsilateral to the symptomatic carotid. We describe the prevalence of microembolic signals (MES), characterize infarct topography, and report clinical outcomes at 90 days. Forty-seven patients, 19 with carotid occlusion and 28 with carotid stenosis, had complete transcranial Doppler recordings and were included in the final analysis. MES were present in 38%. There was no difference in MES between those with carotid occlusion (7/19, 37%) compared with stenosis (11/28, 39%; P=0.87). In patients with radiographic evidence of infarction (n=39), 38% had a watershed pattern of infarction, 41% had a nonwatershed pattern, and 21% had a combination. MES were present in 40% of patients with a watershed pattern of infarction. Recurrent cerebral ischemia occurred in 9 patients (19%; 6 with transient ischemic attack, 3 with ischemic stroke). There was no difference in the rate of recurrence in those with compared to those without MES. Cerebral embolization plays an important role in the pathophysiology of ischemia in both carotid occlusion and stenosis, even among patients with watershed infarcts. The role of aggressive antithrombotic and antiplatelet therapy for symptomatic carotid occlusions may warrant further investigation given our findings.

Symptomatic Occlusion of Internal Carotid Artery Caused by Pituitary Macro Adenoma Among the Patients Without Apoplectic Signs; Case Report and Review of the Literature

Introduction: Pituitary adenoma producing symptomatic carotid compression of the internal carotid artery without any apoplexy sign would be extremely rare and there was only one report regarding to this condition. Case Presentation: In this case report we have described a 57-year-old woman with a nonfunctional pituitary macro adenoma which has resulted to symptomatic internal carotid occlusion. Magnetic resonance imaging (MRI) revealed a large pituitary adenoma caused tight stenosis of right internal carotid. The patient has also experienced the transient ischemic attack which has confirmed to be the cause of internal carotid artery occlusion by this macro adenoma tumor. There was not any sign of apoplexy at the time of admission and the patient has not shown a history of pituitary adenoma. The patient then has undergone an endonasal transsphenoidal resection because of this nonfunctional pituitary adenoma. Conclusions: Pituitary macro adenoma producing symptomatic internal carotid occlusion might develop to several serious conditions including transient ischemic attack. Urgent surgical procedure might be the best approach to prevent further severe complications in such patients.

Symptomatic Occlusion of Internal Carotid Artery Caused by Pituitary Macro Adenoma Among the Patients Without Apoplectic Signs; Case Report and Review of the Literature

Introduction: Pituitary adenoma producing symptomatic carotid compression of the internal carotid artery without any apoplexy sign would be extremely rare and there was only one report regarding to this condition. Case Presentation: In this case report we have described a 57-year-old woman with a nonfunctional pituitary macro adenoma which has resulted to symptomatic internal carotid occlusion. Magnetic resonance imaging (MRI) revealed a large pituitary adenoma caused tight stenosis of right internal carotid. The patient has also experienced the transient ischemic attack which has confirmed to be the cause of internal carotid artery occlusion by this macro adenoma tumor. There was not any sign of apoplexy at the time of admission and the patient has not shown a history of pituitary adenoma. The patient then has undergone an endonasal transsphenoidal resection because of this nonfunctional pituitary adenoma. Conclusions: Pituitary macro adenoma producing symptomatic internal carotid occlusion might develop to several serious conditions including transient ischemic attack. Urgent surgical procedure might be the best approach to prevent further severe complications in such patients.