Intracranial Carotid Stenosis Research Articles

Comparison between intracranial collaterals and cerebral hemodynamics in patients with extracranial carotid stenosis versus combined extra- and intracranial stenosis using transcranial duplex

BackgroundIn acute ischemic stroke, collateral circulation plays an important role in maintaining blood flow to the tissue that is at risk of progressing into ischemia, and in increasing the successful recanalization rate without hemorrhagic transformation.ObjectivesTo compare between collaterals in patients with extracranial carotid stenosis alone and in patients having both extracranial and intracranial carotid stenosis and therefore the difference in prognosis between them.Materials and methodsA total of 30 patients of acute ischemic stroke were enrolled. The extracranial part of the carotid artery was assessed with color-coded duplex. Transcranial color-coded duplex was done to assess cerebral hemodynamics and collaterals to differentiate between extracranial significant carotid stenosis alone versus combined extra- and intracranial significant carotid stenosis.ResultsOut of 15 patients with significant extracranial stenosis, 3 of them obtained reversed flow in the ophthalmic artery and 3 patients of them showed change of flow in the anterior cerebral artery(ACA), whereas the other 15 patients of combined stenosis did not show any reversed blood flow in the same arteries which considered nonsignificant. The residual deficit of patients with extracranial stenosis alone was better when compared to that of the other group.ConclusionOur study concluded that transcranial duplex provides useful information about cerebral reserve and status of collaterals which show nonsignificant difference between two studied groups regarding intracranial collaterals. Furthermore, patients with combined extra- and intracranial stenosis were found to have more deficit and worse prognosis than patients with internal carotid stenosis only.

Cavernous carotid stenosis following stereotactic radiosurgery for Cushing’s disease: A rare complication and review of the literature

Intracranial carotid stenosis or occlusion after SRS is an extraordinarily rare event. Because of the rarity of this event, increased awareness within the neurosurgical community is required. For those with post-radiosurgical carotid stenosis who are asymptomatic, longitudinal follow up is recommended. Management depends on whether the patient is symptomatic or asymptomatic. Those who are symptomatic may require balloon angioplasty, stenting, or bypass surgery.

Abstract WP24: Utility of the Sheath Guide Specifically Designed for Transbrachial Approach in Endovascular Treatment of Neurovascular Diseases

Background and purpose: Transfemoral approach has been a common technique in endovascular treatment (ET) of neurovascular diseases. When aortic or peripheral arterial conditions limit transfemoral approach, transbrachial approach is attempted as the alternative. The purpose of our study was to report the utility of novel sheath guide specifically designed for transbrachial approach in ET for carotid or cerebral vascular pathology. Methods: Included in our analysis were patients who underwent transbrachial ET with the sheath guide for transbrachial approach between 2011 and 2014. The sheath guide has a 6Fr (2.24 mm, 0.088 inch) internal diameter (ID) with 90 cm in length, a soft distal part and a particular distal shape like a modified Simmons catheter. The MSK-guide 7.5 has 7.5 cm of the distal part in length for the common carotid artery and the MSK-guide 15 has 15.0 cm of the distal part in length for the internal carotid artery. Carotid artery stenting and external carotid artery embolization were performed with the MSK-guide 7.5, and ET for intracranial lesions with MSK-guide 15. Results: Two hundred and seventy patients underwent transbrachial ET with the particular sheath guide. The procedures included treatment of 143 extracranial carotid stenosis, 31 intracranial carotid stenosis, 50 intracranial aneurysms, 25 AVMs/DAVFs and 21 acute ischemic strokes. Transbrachial carotid cannulation was easy and successful in every case except for one case (0.4%) with brachial artery spasm. After transbrachial carotid cannulation of MSK-guide, procedures were performed easily through the sheath guide in every case. On sheath-related periprocedural complications, 2 pseudoaneurysms (0.7%) and brachial artery occlusions (0.7%) occurred after ET or a follow-up period, respectively. Conclusion: The sheath guide specifically designed for transbrachial approach provided a favorable impact upon ET of neurovascular diseases.

Pattern of cerebrovascular atherosclerotic stenosis in older Chinese patients with stroke

The clinical pattern and angiographic distribution of cerebral atherosclerosis varies among different ethnic groups. This study was designed to identify the clinical background for intracranial and extracranial atherosclerotic stenosis in older eastern Chinese patients using digital subtraction angiography. We retrospectively reviewed the data collected from the Nanjing Stroke Registry Program, from January 2004 to March 2011. The analysis focused on the intracranial or extracranial location of stenosis in the anterior and posterior circulations. In total, records of 1041 patients were included in the study. Of these patients, 19.88% had intracranial carotid stenosis, 18.73% had stenosis in the extracranial vessels, and 33.33% had concurrent stenoses. A total of 2002 stenotic sites were detected in 749 patients. Among those patients with stenosis, a single stenosis was found in 170 (16.33%) and multiple stenoses were found in 579 (55.62%). The prevalence of intracranial stenosis in the single-stenosis group was 54.12%, while in the multiple-stenosis group it was 47.87% (p=0.127). A higher incidence of severe stenosis (70–99% blockage) and occlusion was found in the intracranial vessels than in the extracranial vessels (p=0.018). Older Chinese patients with atherosclerotic stenosis tend to have more intracranial stenoses.

Hemodynamic relationship between intracranial aneurysm and carotid stenosis: review of clinical cases and numerical analyses

Objective: Coexistence of both an intracranial aneurysm and a stenosis at the same internal carotid artery is infrequent, but it may complicate therapeutic management of either disease. It is unclear if a stenosis plays any role in development of intracranial aneurysms. We study patients with intracranial aneurysms at our hospital and investigate if there is a relationship between a carotid stenosis and an intracranial aneurysm.Methods: Two hundred and nine patients who were treated for their intracranial aneurysms in a 2-year period were reviewed. Fifty-four patients were found to have at least one intracranial aneurysm and one intracranial or extracranial carotid stenosis. Ten of them had bilateral stenoses; 17 aneurysms were on the ipsilateral side of the stenosis, and eight on the contralateral side. Nineteen aneurysms were elsewhere. Two cases were selected for detailed computational fluid dynamics (CFD) analyses: one with an intracranial and the other with an extracranial stenosis.Results: Aneurysms on the contralateral side of a carotid stenosis are significantly larger than those aneurysms on the ipsilateral side or with bilateral stenoses (13.6 versus 6.6 mm; P < 0.01). CFD studies show that wall shear stress at the aneurysm is more likely affected by an adjacent intracranial stenosis than by an extracranial stenosis.Conclusions: Intracranial carotid aneurysms contralateral to a carotid stenosis are significantly larger than aneurysms with a carotid stenosis elsewhere. Rupture can occur on aneurysms with an extracranial carotid stenosis on the contralateral side or with an intracranial carotid stenosis on the ipsilateral side.

Percutaneous carotid artery angioplasty and stenting for ocular ischemic syndrome

To describe percutaneous carotid angioplasty and stenting to treat ocular ischemic syndrome resulting from severe intracranial carotid artery stenosis. Retrospective case series of 3 patients with ocular ischemic syndrome and intracranial carotid artery stenosis. All patients underwent carotid artery evaluation, including ultrasound, transcranial Doppler, magnetic resonance imaging or magnetic resonance angiography,and angiography. Carotid angioplasty and stenting was performed in all patients. Carotid angiography, fluorescein angiography, and transcranial Doppler imaging were used to evaluate cerebral and ocular perfusion. Cerebral perfusion improved in all patients. Fluorescein angiography arteriovenous transit times improved in 2 patients. One patient had a correction in the reversal of flow through the ophthalmic artery. Visual acuity remained stable or improved in all patients. There were no complications associated with the procedure. Intracranial carotid artery stenosis is a rare cause of ocular ischemic syndrome. With the advent of carotid angioplasty and stenting, stenotic lesions previously not amenable to carotid endarterectomy are now treatable with stenting. A complete work-up of the carotid artery is necessary in all cases of ocular ischemic syndrome to ensure evaluation of the entire carotid artery system. Early diagnosis of intracranial carotid stenosis is important for preservation of visual function and reducing risk of cerebral vascular event.

The 27th International Stroke Conference San Antonio, Texas, February 7-9, 2002.

The 27th International Stroke Conference San Antonio, Texas, February 7-9, 2002.

Outcome in Patients with Symptomatic Occlusion of the Internal Carotid Artery or Intracranial Arterial Lesions: A Meta-Analysis of the Role of Baseline Characteristics and Type of Antithrombotic Treatment

Objectives: We performed a systematic review of the literature to assess the impact of potential risk factors of recurrent stroke other than a compromised cerebral blood flow in patients with carotid occlusion or intracranial arterial lesions. In addition, we investigated the effect of treatment with aspirin or oral anticoagulation on recurrent stroke rate and assessed whether the incidence of recurrent stroke has decreased over the years. Methods: We searched Medline (1966 and onwards) and reference lists of identified articles for papers reporting on the recurrent stroke risk in patients with carotid occlusion or intracranial arterial lesions. Two authors independently extracted information from all papers. The influence of study characteristics on the risk of the endpoints ‘recurrent stroke’, ‘ipsilateral stroke’ and ‘vascular death’ was determined by Poisson regression analysis. Rate ratios were calculated per 10 percentage points increase of a characteristic. Results and Conclusions: Patients with intracranial carotid stenosis or occlusion had a higher rate of recurrent stroke (rate ratio 1.09; 95% CI 1.05–1.14) than patients with extracranial carotid occlusion or middle cerebral artery stenosis or occlusion. In patients with bilateral carotid occlusion the rate was lower (rate ratio 0.82; 95% CI 0.68–0.98). No other vascular risk factors than hypertension (rate ratio 1.23; 95% CI 1.07–1.41) could be shown to increase the rate of recurrent stroke. Oral anticoagulation but not aspirin had a protective effect on the incidence of recurrent stroke (rate ratio 0.86; 95% CI 0.79–0.93). The reported rates of recurrent stroke in patients with symptomatic occlusion of the internal carotid artery or intracranial arterial lesions have not decreased over the years.

Hemodynamic instability after carotid endarterectomy: risk factors and associations with operative complications.

To examine the incidences of hypertension, hypotension, and bradycardia after carotid endarterectomy (CEA) and to identify any hemodynamic variables predictive of postoperative stroke, death, or cardiac complications. Retrospective population-based cohort study of 291 consecutive patients undergoing CEA using hospital chart review. Hemodynamic data collected from time of arrival in the recovery room until the end of the 1st postoperative day. Primary and secondary outcome events were stroke or death within 30 days of surgery and any postoperative cardiac complication (angina, congestive heart failure, dysrhythmia, or myocardial infarction), respectively. The incidences of postoperative hypertension (systolic blood pressure > 220 mm Hg), hypotension (systolic blood pressure < 90 mm Hg), and bradycardia (pulse < 60 beats/min) were 9% (26 of 290 cases), 12% (36 of 290 cases), and 55% (159 of 290 cases), respectively. The stroke or death rate was 5.2% (15 of 291 cases). Postoperative hypertension was associated significantly with stroke or death (P = 0.04) and by a statistical trend with cardiac complications (P = 0.07). Independent preoperative risk factors for postoperative hypertension by multivariate analysis included angiographic intracranial carotid stenosis greater than 50%, cardiac dysrhythmia, preoperative systolic blood pressure greater than 160 mm Hg, neurological instability, and renal insufficiency. Postoperative hypotension and bradycardia did not correlate with primary or secondary outcomes. Hemodynamic instability was commonly observed after CEA, but only postoperative hypertension was associated with stroke or death and, possibly, with cardiac complications. Patients undergoing CEA, especially those at risk for postoperative hypertension, may be monitored best in settings suited to the expeditious management of neurological and cardiovascular emergencies.

Pulsatile Tinnitus: Clinical and Angiological Evaluation

Pulse-synchronous tinnitus (PT) is deemed rare, but may be the first symptom of a variety of causes. Between 1987 and 1990, we have studied 23 patients with objective (n = 14) or subjective (n = 9) PT. In 10 patients, PT was the sole complaint. Final diagnoses included dural (n =9) or pial (n = 1) arteriovenous malformation, carotid-cavernous fistula (n = 3), glomus tumor (n = 3), intracranial carotid stenosis (n = 2), complicated migraine (n = 1), subarachnoid hemorrhage associated with Marfan''s syndrome (n = 1), benign intracranial hypertension (n = 1), and venous PT of unknown cause (n = 1). Doppler ultrasound revealed pertinent pathologic findings in 11 of 13 patients studied. Angiography established the final diagnosis in 18 of 21 patients. Therapy reduced or abolished PT in 16 patients. Our findings indicate that unusual causes must be considered in the diagnosis of PT. Even in isolated or subjective PT, a staged diagnostic work-up including angiography should be initiated.

Carbon Dioxide Reactivity of Cerebral Blood Flow Measured by Transcranial Sonography as a Diagnostic Clue to Intracranial Carotid Stenosis in the Presence of Normal Extracranial Cerebral Arteries

The reactivity of the cerebral vasculature, as assessed by the response in the middle cerebral artery blood velocity, measured by transcranial Doppler, to increases in arterial carbon dioxide, has bee

Further lessons from the EC/IC bypass study

Further study of the data from the EC/IC Bypass Trial has been pursued for three specific goals. Firstly, the issue of possible distortion of the conclusions by virtue of noncompliance in the centers with the obligation of randomization has been examined very closely. The thrice-yearly neurosurgical reports from the participating neurosurgeons in the 52 centers which entered 1191 patients (86.5% of the total study), reported that 1249 patients received bypass surgery outside the trial. Of these, 925 were medically ineligible by our protocol requirement, 258 refused to be placed in a trial which required randomization, and a mere 66 were deviated from the trial by a deliberate decision of the participating neurologists or neurosurgeons. The ratio of randomized and eligible to non-randomized and operated is 1191 : 1294, very close to 1 : 1. By contrast in the coronary artery study (CASS) this ratio, favoring non-randomization, was 25 : 1. Our participants in these key centers exhibited a disciplined approach to their commitments to the trial and they failed to randomize willing and eligible subjects on the average of 1.3 times per center every five years.Secondly, a number of prognostic studies were carried out in the medically-treated groups to clarify the impact of certain important variables on the outcome. The differential outcome of the radiological subgroups of TIA and minor stroke patients were examined. In the medically-treated patients, fatal and non-fatal strokes occurred within 18 months in 20% of those with ICA occlusion and continuing symptoms after the diagnostic arteriogram, and in 18% of the patients with intracranial carotid stenosis. By contrast patients with ICA occlusion without new symptoms and the patients with middle cerebral artery stenosis and occlusion had fatal and non-fatal 18 months stroke rates of 14%. At 5 years the patients with ICA occlusion and new symptoms after arteriographic confirmation, and those with ICA intracranial stenosis patients had 35% rates of fatal and non-fatal stroke; the rates for those with ICA occlusion without new symptoms and for MCA stenosis both stand at 30% and for MCA occlusion at 20%.Patients who entered the trial with minor stroke had a minimally worse prognosis than those who entered with TIA. The occurrence of recent events (less than 30 days prerandomization) portend greater risk of stroke than later events (30-91 days). Frequency of TIA in the 3 months prior to entry made a substantial difference, with the worst outlook for those having 3 or more compared with those having 2 or less ischemic events in this time-period. Except for those patients entering with recent stroke and having 2 or less TIA's in the 3 months pre-entry period, the highest rate of stroke and fatal stroke was in the 12 weeks period after entry.Thirdly, further intensive search has been made for possible subgroups which might benefit in strokeprevention from bypass surgery. None have surfaced including those with recent or frequent ischemic events, and in those without evidence of good collateral supply in the presence of occluded or stenosed MCA or similar occlusive or stenotic lesions of the ICA. It should be re-emphasized that this was not atrial to validate or deny benefit in ischemic recovery. Such a trial has never been conducted.