Intracranial Intracranial Internal Carotid Artery Research Articles

Abstract No. 151: Safety, feasibility, and mid-term follow-up of Willis stent graft placement in the treatment of symptomatic complicated intra- or extra-cranial aneurysms: A multicenter experience

Endovascular coil embolization in the treatment of symptomatic complicated intra- or extracranial aneurysms (SCIEAs) may be associated with high risk. We report the technical success rate and mid-term follow-up results after deploying stent grafts to treat a cohort of patients with SCIEAs. This study was a retrospective review of 58 patients (39 male; mean age 40.4 ± 12.3 years, range 11–64) with 60 SCIEAs treated by 67 Willis covered stents at three medical centers in China between April 2005 and January 2010. The locations of the SCIEAs were as follows: intracranial internal carotid artery (ICA) in 54 patients, extracranial ICA in one, intracranial vertebral artery (VA) in three and extra-cranial VA in two. Surgery was successful in 59 (98.3%) SCIEAs. Total exclusion was immediately achieved in 48 SCIEAs, and minor endoleaks were present in 11. Acute thrombosis occurred in two patients and hemorrhage in one. Follow-up angiography (mean 13.8 ± 8.9 months, range 1–41) revealed that 49 of 52 (94.2%) aneurysms were completely isolated, with mild in-stent stenosis in only two patients and in-stent occlusion in one patient. Willis stent-graft application is an alternative therapy to treat SCIEAs in either intra- or extracranial ICAs or VAs. In the case of a tortuous intracranial ICA or potential side branch coverage, however, it is still not a first choice.

Carotid and cerebrovascular disease in symptomatic patients with type 2 diabetes: assessment of prevalence and plaque morphology by dual-source computed tomography angiography

BackgroundPlaque morphology directly correlates with risk of embolism and the recently developed dual-source computed tomography angiography (DSCTA) may help to detect plaques more precisely. The aim of our study was to evaluate the prevalence and morphology of carotid and cerebrovascular atherosclerotic plaques in patients with symptomatic type 2 diabetes mellitus (DM) by DSCTA.MethodsFrom July 2009 to August 2010, DSCTA was prospectively performed in 125 consecutive patients with symptomatic type 2 DM. We retrospectively analyzed plaque type, distribution, and extensive and obstructive natures were determined for each segment for all patients.ResultsAtherosclerotic plaques were detected in 114 (91.2%) patients. Relatively more noncalcified (45%) and calcified (39%) plaques and less mixed (16%) plaques were observed (p < 0.001). Noncalcified plaques were found mainly in the intracranial arteries (81.8%), mixed plaques in the intracranial arteries (25.2%) and intracranial internal carotid artery (ICA) (56.1%). Calcified plaques were found mainly in the intracranial ICA (65.9%) and extracranial arteries (28.2%) (for all, p < 0.001). Extension of plaques from the 1st to 5th segments was observed in 67 (58.8%) patients and from the 6th to 10th segments in 35 (30.7%) patients. The most common site of all detected plaques was the cavernous segment. Regarding stenosis, there were significantly more nonobstructive than obstructive stenosis (91% vs. 9%, p < 0.001).ConclusionDSCTA detected a high prevalence of plaques in patients with symptomatic type 2 DM. A relatively high proportion of plaques were noncalcified, as well as with nonobstructive stenosis. The distribution of plaques was extensive, with the cavernous portion of ICA being the most common site.

Safety, feasibility, and mid-term follow-up of Willis stent graft placement in the treatment of symptomatic complicated intra- or extra-cranial aneurysms: A multicenter experience

We report the technical success rate and mid-term follow-up results after deploying stent-grafts to treat a cohort of patients with symptomatic complicated intra- or extracranial aneurysms (SCIEAs). This study was a retrospective review of 58 patients (39 male; mean age 40.4 ± 12.3 years) with 60 SCIEAs treated by 67 Willis covered stents at three medical centers in China between April 2005 and January 2010. The locations of the SCIEAs were as follows: Intracranial internal carotid artery (ICA) in 54 patients, extracranial ICA in one, intracranial vertebral artery (VA) in three and extra-cranial VA in two. Surgery was successful in 59 (98.3%) SCIEAs. Total exclusion was immediately achieved in 48 SCIEAs, and minor endoleaks were present in 11. Acute thrombosis occurred in two patients and hemorrhage in one. Follow-up angiography (mean 13.8 ± 8.9 months) revealed that 49 of 52 (94.2%) aneurysms were completely isolated, with mild in-stent stenosis in only two patients and in-stent occlusion in one patient. Willis stent-graft application is an alternative therapy to treat SCIEAs in either intra- or extracranial ICAs or VAs. In the case of a tortuous intracranial ICA or potential side branch coverage, however, it is still not a first choice.

Distribution of Internal Elastic Lamina and External Elastic Lamina in the Internal Carotid Artery: Possible Relationship With Atherosclerosis

The intracranial internal carotid artery (ICA) is a muscular artery and lacks external elastic lamina (EEL). Stenosis of the intracranial ICA is relatively uncommon, but the most common site is the cavernous portion. The characteristics of the arterial wall structures were examined using serial 3-mm sections of 32 intracranial ICAs obtained from 50 cadavers to identify where the EEL disappeared. The portions of the ICA where the intima exhibited thickening were also determined. Both the internal elastic lamina (IEL) and EEL were observed in all 32 specimens of the petrous portion of the ICA. Only the IEL was observed in all 32 specimens of the intradural portion of the ICA. The EEL had disappeared in 31 of the 32 specimens of the horizontal segment of the cavernous portion of the ICA. Intimal thickening of the ICA was observed in 23 of 32 ICA specimens, and frequently appeared in the horizontal segment of the cavernous portion of the ICA. The EEL disappeared in the cavernous portion of the ICA, which is the most common site of stenosis of the intracranial ICA. Change in the elasticity of the arterial wall in the cavernous portion may be an important factor in the process of atherosclerosis in the intracranial ICA.

Transcranial Color-Coded Sonography Successfully Visualizes All Intracranial Parts of the Internal Carotid Artery Using the Combined Transtemporal Axial and Coronal Approach

Visualization of the intracranial internal carotid artery (ICA) with transcranial color-coded sonography (TCCS) by using the transtemporal coronal plane has been described previously. Because this approach is limited to the vertical running ICA segments, we investigated the feasibility of using TCCS to visualize all intracranial ICA segments by adding the transtemporal axial approach to the coronal plane. Subjects with excellent transtemporal acoustic windows were examined by TCCS by using standardized axial and coronal planes. Identification rate, flow velocities, pulsatility and resistance indices, and length (as visible in color-coded power mode) were determined. A total of 120 intracranial ICAs from 60 subjects were investigated. By switching between the axial and coronal insonation planes, all intracranial segments of the ICA could be investigated in 100% of subjects-with the exception of the horizontal part of the petrosal ICA, which was identified in 96.7% of subjects. TCCS becomes a reliable tool in investigating all parts of the intracranial ICA by adding the transtemporal axial approach to the coronal plane.

Asymmetry of intracranial internal carotid artery on 3D TOF MR angiography: a sign of unilateral extracranial stenosis

The purpose of this case-control study was to determine whether an asymmetry of size of the intracranial internal carotid artery (ICA) on 3D time-of-flight MR angiography (MRA) is predictive of a high-grade cervical ICA stenosis. Ninety-six stroke/TIA consecutive patients were recruited for the study, of whom 32 had unilateral high-grade ICA stenosis (>or=70% NASCET) and were included into the case group, and the remaining 64 did not have such high-grade stenosis and were included in the control group. On intracranial MRA, two observers, blinded to the characteristics of cervical ICA stenosis, independently searched for qualitative size asymmetry between ICAs and measured the cross-sectional surface of the intracranial ICAs. An intracranial size asymmetry was seen in 28 of the 32 high-grade stenoses by both readers, and in 10 (reader(1)) and 8 (reader(2)) of the 64 controls (sensitivity =88%, specificity =84-88%). In patients without agenesia of the A1 segment of the circle of Willis (n=70), sensitivity was >or=90% and specificity =96%. Surfaces ratios were significantly different (p<0.001) between cases and controls. However, using ROC curves analysis, the quantitative processing did not improve the detection when compared with the qualitative assessment of intracranial ICA asymmetry. A size asymmetry of the intracranial ICAs reveals the presence of an underlying high-grade cervical stenosis, with a high degree of confidence, especially in patients without anatomical variant of the anterior part of the circle of Willis. This sign may allow an early detection of high-grade cervical carotid stenosis in stroke patients before dedicated neck imaging is performed.

Transcranial Color-Coded Duplex Sonography for Detection of Distal Internal Carotid Artery Stenosis

Gradation of high-grade intracranial internal carotid artery (ICA) stenosis poses a challenge to noninvasive neurovascular imaging, which seems critical for angioplasty in the ICA segments C1 and C5. We investigated cutoff values of intracranial ICA stenosis for transcranial color-coded sonography (TCCS) and compared this method with the "gold standard," digital subtraction angiography (DSA). Forty patients (mean age, 58.9 +/- 13.8 years) with intracranial ICA lesions were prospectively examined by using TCCS and DSA. Two standard TCCS coronal imaging planes were used to evaluate the intracranial ICA. In addition, a control group of 128 volunteers without cerebrovascular disease (mean age, 48.8 +/- 15.9 years) was investigated to establish standard velocity values. DSA confirmed 96 stenoses and 8 occlusions of the intracranial ICA in the study population. In 9% and 7% of cases, stenosis confined to the C1 or C5 segment was >50% and 70%, respectively. Receiver-operating curves demonstrated cutoff values for >70% stenosis in C1 when the peak systolic velocity (PSV) was >200 cm/s (specificity, 100%; sensitivity, 71%) or the C1/submandibular ICA index was >3 (specificity, 93%; sensitivity, 86%). TCCS is a reliable adjunctive method to detect and quantify significant stenosis of the intracranial ICA. The assessment of the C1/ICA index and peak systolic velocities maximizes the diagnostic accuracy of C1 stenosis to >70% when extracranial ICA stenosis coexists. Further studies need to be performed to compare the diagnostic accuracies of MR angiography and TCCS with that of DSA.

Mechanical Thrombectomy of Intracranial Internal Carotid Occlusion

Acute stroke from occlusion of the intracranial internal carotid artery (ICA) generally has a poor prognosis and appears to respond poorly to intravenous thrombolysis. Mechanical thrombectomy is a newly available modality for acute stroke therapy, but it is unknown whether this endovascular therapy may have a role in the specific setting of intracranial ICA occlusion. We therefore assessed the success rate of the Merci Retriever mechanical thrombectomy device in recanalization of intracranial ICA occlusions and sought to determine whether ICA recanalization with this therapy can result in better outcomes. All patients with acute stroke from intracranial ICA occlusion were identified in the MERCI and Multi MERCI Part I trials. We determined the success rate of ICA recanalization with endovascular thrombectomy and then assessed clinical outcomes according to whether vessel recanalization was successful. Eighty patients with acute stroke from intracranial ICA occlusion were identified. Of these 80 patients, 53% had successful ICA recanalization with the Merci Retriever alone and 63% had ICA recanalization with use of the Merci Retriever plus adjunctive endovascular treatment. Baseline patient characteristics and procedural complications did not differ between the recanalized and nonrecanalized groups. Good clinical outcome, defined by a modified Rankin Scale of 0 to 2 at 90 days, occurred in 39% of patients with ICA recanalization (n=19 of 49) and in 3% of patients without ICA recanalization (n=1 of 30) (P<0.001; one patient was lost to follow up for 90-day modified Rankin Scale). Ninety-day mortality was 30% (n=15 of 50) in the recanalized group and 73% (n=22 of 30) in the nonrecanalized group (P<0.001). Symptomatic hemorrhage was not significantly different between the recanalized (6% [n=3 of 50]) and nonrecanalized (16.7% [n=5 of 30]) groups (P=0.14). Hemorrhage rates were also not found to be influenced by use of intravenous thrombolysis before mechanical thrombectomy. Multivariable logistic regression identified ICA recanalization (OR=28.4, 95% CI=2.6 to >99.9) and lack of history of hypertension (OR=0.15, 95% CI=0.04 to 0.57) as significant predictors of a good 90-day outcome. Failure to recanalize the ICA (OR=0.16, 95% CI=0.05 to 0.51) and age (per decade, OR=1.07, 95% CI=1.03 to 1.13) were significant predictors of mortality at 90 days. Mechanical thrombectomy of acute intracranial ICA occlusion using the Merci Retriever device, alone or in combination with adjunctive endovascular therapy, has a high rate of successful vessel recanalization. Subjects with successful ICA recanalization by this method have improved poststroke clinical outcome and survival compared with subjects in which the ICA is not successfully recanalized.

Carotid Ultrasound Criteria for Detecting Intracranial Carotid Stenosis

Background/Aims: This study attempted to establish carotid ultrasound criteria for identifying stenosis of the intracranial internal carotid artery (ICA) and middle cerebral artery (MCA). Methods: Two hundred and fifty-five patients were enrolled. Ultrasound measurements for common carotid artery (CCA) and ICA were as follows: flow volume (FV), peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistance index (RI). The sensitivity and specificity of the ultrasound criteria for determining intracranial ICA or MCA ≧50% stenosis were calculated. Results: The criteria identified for detecting intracranial ICA ≧50% stenosis were ICA FV <159 ml/min, ICA PSV <33 cm/s and CCA PSV <42 cm/s. When ICA PSV <33 cm/s was combined with CCA PSV <42 cm/s, sensitivity increased to 82%, with 91% specificity. The criteria identified for detecting MCA ≧50% stenosis were CCA FV <285 ml/min, ICA FV <179 ml/min, ICA PSV <33 cm/s, >35% reduction in FV in the CCA, >40% reduction in FV in ICA, and >35% reduction in PSV in ICA. When these criteria were combined, sensitivity increased to 69%, with 85% specificity. Conclusion: This study demonstrated that ultrasound criteria are sensitive and specific for detecting intracranial ICA and MCA significant obstruction.

頭蓋内外内頸動脈の血管構造に関する検討

The intracranial internal carotid artery (ICA) is well known to be a muscular artery that lacks an external elastic lamina. Elastic fibers are concentrated inside the internal elastic lamina of the wall of the intracranial ICA. We examined a portion where the external elastic lamina disappeared in the course of the ICA. We extirpated 32 intracranial ICA specimens from 50 cadavers. We made running specimens of the ICA every 3 mm and stained them using the Elastica van Gieson method and then investigated a portion where the external elastic lamina disappeared in the wall of the ICA. We also examined the intimal thickness of various portions of the ICA. We identified both the internal elastic lamina and the external elastic lamina in the petrous portion of the ICA in all cases. In the intradural portion of the ICA, the external elastic lamina was not recognized and only the internal elastic lamina was seen in all cases. In 31 of the 32 specimens (98%), the external elastic lamina disappeared in the horizontal portion of the cavernous portion of the ICA. The intimal thickness of the ICA was recognized in 23/32 specimens. The starting point of the intimal thickness approximated the portion where the external elastic lamina disappeared. The external elastic lamina of the ICA disappeared at the horizontal portion of the cavernous sinus, which was a site where intimal thickness was frequently observed. Changes in the elasticity of the wall of the intracranial ICA may therefore cause atherosclerotic changes in the ICA.

Neuroendovascular therapy combined with neurosurgery for large and giant intracranial internal carotid artery aneurysm presenting mass effect

Introduction: Large and giant intracranial internal carotid artery (ICA) aneurysms presenting mass effect are sometimes treated by combined neuroendovascular therapy and neurosurgery. In this article, we survey such kinds of combined treatment in our institute. Materials and Methods: Sixteen patients underwent such a treatment, out of 60 cases, with large and giant intracranial ICA aneurysms presenting mass effect. Neuroendovascular therapy included proximal occlusion of ICAs in 13 patients and trapping of ICAs, together with aneurysms in 3 patients. Neurosurgery included vein grafting in nine patients and superficial temporal artery–middle cerebral artery anastomosis in seven patients. Results: Clinical symptoms improved immediately in 12 of the patients. Symptomatic impairment of ipsilateral cerebral blood flow was observed in two of them and visual acuity disturbance caused by ophthalmic artery occlusion in one. The advantage of endovascular occlusion over surgical ligation is to occlude ICAs as close to the aneurysm as possible to avoid collateral flow to the aneurysm. Conclusion: Neuroendovascular therapy, combined with neurosurgery for large and giant intracranial internal carotid artery aneurysms presenting mass effect, is a useful treatment option.

Prediction of early neurological deterioration using diffusion- and perfusion-weighted imaging in hyperacute middle cerebral artery ischemic stroke.

Early neurological deterioration (END) occurs in approximately one third of all ischemic stroke patients and is associated with a poor outcome. Our study sought to assess the value of ultra-early MRI in the prediction of END in stroke patients. Between August 1999 and November 2001, 38 stroke patients with a proven middle cerebral artery (MCA) or intracranial internal carotid artery (ICA) occlusion on MR angiography underwent perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) within 6 hours after onset, and 30 fulfilled all inclusion criteria. Control DWI and MR angiography were performed between days 3 and 5. Cranial CT was performed to rule out hemorrhagic transformation. Vascular risk factors, temperature, blood pressure, glycemia, and blood count were assessed on admission. National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and at 6, 12, 24, and 48 hours. At the same time points, transcranial Doppler (TCD) examinations were conducted to assess arterial recanalization. END was defined as an increase in the NIHSS score >4. A logistic regression model was applied to detect independent predictors of END. The Kruskal-Wallis test was used to evaluate the relationship between infarct growth and duration of vessel occlusion. Initial MR angiography showed an occlusion of intracranial ICA in 7 patients (23.3%), of proximal MCA in 14 (46.6%), and of distal MCA in the remaining 9 (30%). A PWI-DWI mismatch >20% was observed in 28 patients (93.3%). END occurred in 7 patients (23.3%). Baseline NIHSS score (P=0.05), proximal site of occlusion (P=0.002), initial DWI (P=0.002) and PWI (P=0.003) volumes, and reduced PWI-DWI mismatch (P=0.038) were associated with END in the univariate analysis. Only hyperacute DWI volume remained as a predictor of END when a logistic regression model was applied (odds ratio, 11.5; 95% CI, 2.31 to 57.10; P=0.0028). A receiver operator characteristic curve identified a cutoff point of DWI >89 cm(3) (sensitivity, 85.7%; specificity, 95.7%) to predict END. A graded response was seen in DWI lesion expansion in relation to duration of arterial occlusion (P=0.017). Ultra-early DWI is a powerful predictor of END after MCA or intracranial ICA occlusion.

Spontaneous intracranial internal carotid artery dissection: report of 10 patients.

Spontaneous intracranial internal carotid artery (ICA) dissection is an uncommon cause of cerebral infarction, particularly when compared with the dissection of the ICA's cervical portion. Most reports describe extensive strokes with very high mortality rates. To report the clinical and radiological findings of 10 patients with spontaneous intracranial ICA dissection. Ten patients (5 women) were included with ages ranging from 15 to 59 years (mean age, 28 years). Nine patients had a stroke (1 had an associated subarachnoid hemorrhage), whereas 1 patient had only transient ischemic attacks. Severe retro-orbital or temporal headache followed by contralateral hemiparesis was the most common initial clinical symptom. No patient had vascular risk factors or a history of neck or head trauma. Stenosis of the supraclinoid portion of the ICA occurred in 8 patients, with extension to the middle cerebral artery or anterior cerebral artery in 2 patients each. Aneurysm formation in the ipsilateral anterior cerebral artery was seen in 1 patient. Two patients had a total occlusion of the supraclinoid portion of the ICA. All patients did well, with no (n = 3), mild (n = 4), or moderate (n = 3) disability on the Modified Rankin Scale during a 3-month follow-up period. Spontaneous intracranial ICA dissection can cause ischemic stroke with or without subarachnoid hemorrhage and should be considered in the differential diagnosis of intracranial ICA stenosis or occlusion, especially in young patients. Some patients survive with few or moderate deficits.

Detection of stenoses in the anterior circulation using frequency-based transcranial color-coded sonography

Atherosclerotic stenoses of the intracranial vessels are less frequent than those of the extracranial vessels, but they are associated with a considerable annual stroke rate. The aim of the present study was to investigate the usefulness of frequency-based transcranial color-coded sonography (TCCS), transcranial Doppler sonography (TCD) and digital subtraction angiography (DSA) in patients with middle cerebral artery (MCA) and intracranial internal carotid artery (ICA) stenosis. Forty patients presenting with 48 intracranial stenoses of the anterior circulation were involved in the study. The stenoses were detected in the neurovascular laboratory during routine TCD examinations. All patients underwent an additional frequency-based TCCS examination. Both the axial and coronal planes were obtained to allow the exact localization of MCA stenosis and differentiation from intracranial ICA stenosis. Angle-corrected flow velocity measurements were performed if straight vessel compartments were 20 mm or more in length. A total of 18 stenoses (44%) were investigated additionally with DSA. According to the investigation with TCD, 20 (42%) stenoses were low-grade, 12 (25%) were moderate, and the remaining 16 (33%) were severe. Angle-corrected flow velocity measurements obtained with the integrated pulse-wave Doppler device of the TCCS machine were highly correlated (0.912, p < 0.001) with those obtained with TCD. TCCS achieved a reliable differentiation of MCA main stem stenosis vs. intracranial ICA stenosis in 7 patients and vs. MCA branch stenosis in 4 patients, but TCD failed in these two subgroups. The agreement between DSA and TCCS to evaluate semiquantitatively 18 intracranial stenoses resulted in a weighted-kappa value of 0.764. The major clinically relevant advantages of TCCS over TCD in MCA stenosis are its ability to differentiate MCA trunk stenosis from terminal ICA or MCA branch stenosis reliably and to perform angle-corrected flow velocity measurements.

Natural history of stenosis from intracranial atherosclerosis by serial angiography.

Knowledge of the natural history of stenoses due to intracranial atherosclerosis may be useful for evaluating possible treatments such as angioplasty. We retrospectively reviewed records over a 7-year period to identify patients with intracranial atherosclerotic stenoses and serial angiograms. Quantitative measurements of stenoses were made in a blinded manner, and clinical outcomes were reviewed. We identified 21 patients with 45 intracranial stenoses who underwent repeat angiography at an average interval of 26.7 months. The average stenosis for all intracranial lesions was 43.9% initially and 51.8% on follow-up (P=.032). The average stenosis in the intracranial internal carotid artery (ICA) was stable (51.2% versus 52.6%). The average stenosis in the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) progressed from 32.4% to 49.7% (P=.037). Based on a minimum 10% change, 20% of intracranial ICA lesions progressed compared with 61% of ACA, MCA, and PCA lesions. Regression occurred in 14% of the intracranial ICA group and 28% of the ACA-MCA-PCA group. Cerebrovascular events were infrequent during this period, with 4 transient ischemic attacks and 1 intracerebral hemorrhage. Intracranial atherosclerotic stenoses are dynamic lesions demonstrating both progression and regression.

Fenestration of the Intracranial Internal Carotid Artery

A rare case of fenestration of the intracranial internal carotid artery (ICA) was identified by angiography in a 51-year-old female with suspected subarachnoid hemorrhage. Only two similar cases have been reported previously. Fenestration tends to develop on the right side and near the bifurcation of the ophthalmic artery. Congenital factors at the 4 mm embryonic stage may be involved in the fenestration of the intracranial ICA.