Stenosis Of Distal Internal Carotid Arteries Research Articles

Associations between atherosclerotic luminal stenosis in the distal internal carotid artery and diffuse wall thickening in its upstream segment.

Significant atherosclerotic stenosis or occlusion in the distal internalcarotid artery(ICA) may induce diffuse wall thickening (DWT) in the upstream arterial wall. This study aimed to assess the association of atherosclerotic steno-occlusive diseases in the distal ICA with DWT in the upstream ipsilateral ICA. Individuals with atherosclerotic stenosis in the distal ICA, detected by carotid MR vessel wall imaging using 3D pre- and post-contrast T1 volume isotropic turbo spin-echo acquisition (T1-VISTA) sequence, were enrolled. The associations of vessel wall thickening, the longitudinal extent of DWT, enhancement of the upstream ipsilateral ICA, and stenosis degree in the distal ICA were examined. Totally 64 arteries in 55 patients with atherosclerotic steno-occlusive distal ICAs were included. Significant correlations were found between distal ICA stenosis and DWT in the petrous ICA (r = 0.422, p = 0.001), DWT severity (r = 0.474, p < 0.001), the longitudinal extent of DWT in the ICA (r = 0.671, p < 0.001), enhancement in the petrous ICA (r = 0.409, p = 0.001), and enhancement degree (r = 0.651, p < 0.001). In addition, high degree of enhancement was correlated with both increased wall thickness and increased prevalence of DWT in the petrous ICA (both p < 0.001). DWT of the petrous ICA is commonly detected in patients with atherosclerotic steno-occlusive disease in the distal ICA. The degree of stenosis in the distal ICA is associated with wall thickening and its longitudinal extent in the upstream segments. Diffuse wall thickening is a common secondary change in atherosclerotic steno-occlusive disease in the intracranial carotid. This phenomenon constitutes a confounding factor in the distinction between atherosclerosis and inflammatory vasculopathies, and could be reversed after alleviated atherosclerotic stenosis. • Diffuse wall thickening of the petrous internal carotid artery is commonly detected in patients with atherosclerotic steno-occlusive disease in the distal internal carotid artery. • The phenomenon of diffuse wall thickening could be reversed after stenosis alleviation. • Carotid artery atherosclerosis with diffuse wall thickening should warrant a differential diagnosis from other steno-occlusive diseases, including moyamoya diseases and Takayasu aortitis.

Vessel Wall Magnetic Resonance Imaging of Bilateral Distal Internal Carotid Artery Stenosis in Intracranial Giant Cell Arteritis

Vessel Wall Magnetic Resonance Imaging of Bilateral Distal Internal Carotid Artery Stenosis in Intracranial Giant Cell Arteritis

Short- and Mid-Term Outcomes of Stenting in Patients with Isolated Distal Internal Carotid Artery Stenosis or Post-Surgical Restenosis.

The aim was to evaluate the outcome of stenting in patients with isolated distal internal carotid artery (ICA) stenosis or post-surgical restenosis, as no data are currently available in the literature. Sixty-six patients (men, N = 53; median age: 66 [IQR, 61–73] years) with ≥50% distal ICA (re)stenosis were included in this single-center retrospective study. The narrowest part of the (re)stenosis was at least 20 mm from the bifurcation in all patients. Patients were divided into two etiological groups, atherosclerotic (AS, N = 40) and post-surgical restenotic (RES, N = 26). Postprocedural neurological events were observed in two patients (5%) in the AS group and in two patients (7.7%) in the RES group. The median follow-up time was 40 (IQR, 18–86) months. Three patients (7.5%) in the AS group had an in-stent restenosis (ISR) ≥ 50%, but none in the RES group. Three patients (7.5%) in the AS group and seven patients (26.9%) in the RES group died. None of the deaths in the RES group were directly related to stenting itself. The early neurological complication rate of stenting due to distal ICA (re)stenoses is acceptable. However, the mid-term mortality rate of stenting for distal ICA post-surgical restenoses is high, indicating the vulnerability of this subgroup.

Carotid Artery Stenosis and Ischemic Strokes in Patients with Giant Cell Arteritis: A Characteristic Pattern-Literature Review and Case Report.

Purpose Ischemic stroke is a relatively rare complication of giant cell arteritis often accompanied by vessel stenosis. Our purpose was to compare the location of internal carotid artery stenosis in GCA patients by performing a literature review suggesting a specific and characteristic pattern. Methods We performed a PubMed research including all articles and cited articles reporting cases and case series about giant cell arteritis patients with internal carotid artery stenosis and ischemic strokes. Results In this case series 39 cases were included. We found a clear tendency of giant cell arteritis-related stenosis to be in the intracranial segments (35/39 (89.7%)). Only in 8/39 (20.5%) patients there was further involvement of extracranial segments. Many cases (27/39 [69.2%]) showed a bilateral involvement. Discussion This literature review reveals a specific pattern of internal carotid artery involvement in patients with giant cell arteritis and ischemic strokes. To our knowledge this pattern has not been reported as a sign strongly pointing toward giant cell arteritis before. We have not found case reports mentioning other common types of vasculitis reporting this involvement pattern. Conclusion Internal carotid artery stenosis and ischemic stroke is a rare complication in patients with giant cell arteritis. Considering the characteristic features of bilateral distal internal carotid artery stenosis giant cell arteritis should be suspected which potentially leads to an early diagnosis and immunotherapy.

Transcarotid repair of carotid artery pseudoaneurysm after carotid artery endarterectomy with tandem distal internal carotid artery stenosis.

Pseudoaneurysm development after carotid endarterectomy is a rare occurrence. Even rarer is pseudoaneurysm formation associated with a distal carotid artery stenosis. We report the case of stent grafting of a carotid artery pseudoaneurysm and tandem high-grade distal stenosis through a transcarotid approach with active flow reversal. No reported cases of a transcarotid artery approach to address a carotid artery aneurysm with tandem stenosis were found in the literature. We show that it may be a safe alternative to a transfemoral artery approach or open surgery.

Improved Carotid Stenosis Quantification on Novel 4D/3D-Doppler Ultrasonography Indexing to the Common Carotid Artery.

The accuracy of internal carotid artery stenosis (ICAS) quantification depends on the method of stenosis measurement, impacting therapeutic decisions and outcomes. The NASCET method references the stenotic to the distal ICAS lumen, the ECST method to the local outer and the common carotid artery (CC) method to the CC diameter. Direct morphometric stenosis measurement with four-dimensionally guided three-dimensional ultrasonography (4D/3DC-US) demonstrated good validity for the commonly used NASCET method. The NASCET definition has clinically relevant drawbacks. Our purpose was to investigate the validity of the ECST and CC methods. 4D/3DC-US percent-stenosis measures of 103 stenoses (80 patients) were compared to quantitative catheter angiography and duplex ultrasonography (DUS) in a blinded fashion. The 4D/3DC-US versus angiography intermethod standard deviation of differences (SDD, n = 103) was lower for the CC method (5.7 %) compared to the NASCET (8.1 %, p < 0.001) and ECST methods (9.1 %, p < 0.001). Additionally, it was lower than the NASCET angiography interrater SDD of 52 stenoses (SDD 7.2 %, p = 0.047) and non-inferior for the ECST method (p = 0.065). Interobserver analysis of equivalent grading methods showed no differences for the SDDs between angiography and 4D/3DC-US observers (p > 0.076). Binary comparison to angiography showed equal Kappa values > 0.7 and an accuracy ≥ 85 % for the NASCET and CC methods, higher than for the ECST method. The binary accuracy of ICAS grading did not differ from DUS for all methods. The new 4D/3DC-US CC method is an accurate and well reproducible alternative to the NASCET and ECST methods and offers potential for clinical application.

Abstract 724: Improved Carotid Stenoses Quantification on Novel 4D/3D-Doppler Ultrasonography Indexing to the Common Carotid Artery

Objective: Accuracy of internal carotid artery stenosis (ICAS) quantification depends on the method of stenosis measurement, impacting therapeutic decisions and outcomes. The NASCET-method references the stenotic to the distal ICAS lumen, the ECST-method to the local outer and the common carotid artery (CC) method to the CC-diameter. Direct morphometric stenosis measurement with four-dimensionally guided three-dimensional ultrasonography (4D/3DC-US) demonstrated good validity for the commonly used NASCET-method. The NASCET-definition has clinically relevant drawbacks. Our purpose was to investigate the validity of the ECST- and CC-method. Approach: 4D/3DC-US percent-stenosis measures of 103 stenoses (80 patients) were compared to quantitative catheter angiography and duplex-ultrasonography (DUS) in a blinded fashion. Results: The 4D/3DC-US versus angiography intermethod standard deviation of differences (SDD, n = 103) was lower for the CC (5.7%) compared to the NASCET- (8.1%, p &lt;0.001) and ECST-method (9.1%, p &lt;0.001). Additionally, it was lower than the NASCET angiography interrater SDD of 52 stenoses (SDD 7.2%, p = 0.047) and non-inferior for the ECST-method (p = 0.065). Interobserver analysis of equivalent grading methods showed no differences for the SDDs between angiography and 4D/3DC-US observers (p &gt;0.076). Binary comparison to angiography showed equal Kappa values &gt;0.7 and an accuracy &gt;85% for the NASCET- and CC-method, higher than for the ECST-method. Binary accuracy of ICAS grading did not differ from DUS for all methods. Conclusion: The new 4D/3DC-US CC-method is an accurate and well reproducible alternative to the NASCET- and ECST-method and offers perspectives for clinical application.

Determinants of Basal Collaterals in Moyamoya Disease: Clinical and Genetic Factors

Background/Aims: To enable the diagnosis of moyamoya disease (MMD), detection of distal internal carotid artery stenosis and hazy network of basal collaterals (BCs) are required. This study aimed at evaluating the factors that could determine the degree of BCs in patients with angiographically confirmed MMD. Methods: We analyzed 146 consecutive patients with MMD (age 26.2 ± 19.6, range 1-75). The degree of BCs (%) was measured based on conventional angiography. Factors associated with the degree of BCs, including clinico-radiological and genetic factors (p.Arg4810Lys variant), were analyzed. Results: The degree of BCs varied among MMD patients and significantly decreased with an increase in the age of diagnosis of MMD (coefficient -1.55; p < 0.001). Although the degree of BC development depends on the MMD stage (Suzuki stage), it is less prominent in adult-onset (>18 years) MMD compared to childhood MMD. The presence of p.Arg4810Lys variant, types of MMD (bilateral vs. unilateral) and stroke (ischemic, hemorrhagic, or asymptomatic), shrinkage (outer diameter) of intracranial vessels, external carotid collateral status, and cortical neovascularization were not associated with the degree of BCs. Conclusion: Although prominent BCs are required for diagnosis of MMD, BCs are decreased with aging, suggesting that angiogenic capacity is altered in adult onset MMD compared to childhood MMD.

Abstract 2786: Moyamoya Syndrome Associated With Graves' Disease: Report Of 16 Cases

Background and purpose Moyamoya disease is a cerebrovascular disorder characterized by bilateral progressive stenosis and occlusion of terminal portions of internal carotid artery (ICA) accompanying by typical net-like collateral vessels. Patients with both the characteristic moyamoya vasculopathy and the associated conditions are categorized as moyamoya syndrome. These conditions include sickle cell disease, neurofibromatosis type 1, Down’s disease, cranial therapeutic irradiation and other rare diseases. Moyamoya syndrome associated with Graves’ disease has been rarely reported and the underlying coexisting mechanism remains unclear. The aim of this study is to identify the clinical and radiological findings of the patients with simultaneous diagnosis of moyamoya syndrome and Graves’ disease. Possible mechanisms predisposing these individuals to ischemic accidents are discussed. Methods We retrospectively identified 12 patients in Peking Union Medical College Hospital and 4 patients in 307 hospital of PLA between May 2000 and December 2010. All patients were female and mean age (range) was 35.13±12.34 years (11-57 years). The patients were diagnosed with Graves’ disease in endocrinology clinic which meet the full diagnostic criteria and no atherosclerotic factor was found in them. Moyamoya vasculopathy was definitely or probably diagnosed by digital subtract angiography or magnetic resonance angiography. The clinical characteristics and prognosis, laboratory data, vascular radiological characteristics were all collected. Results Stenosis or occlusion of bilateral distal ICA and/or proximal anterior /middle cerebral arteries was found in 13 patients. Three patients had unilateral distal ICA stenosis and abnormal collateral vessels. PCA stenosis was found in 2 patients. Fifteen patients presented with infarction or transient ischemic attack and one with dizziness. Interestingly, thyroid function tests demonstrated predominantly elevated thyroxine and suppressed thyroid stimulating hormone level in 15 patients when cerebrovascular accidents occurred. All patients received antithyroid therapy and two had recurrent ischemic attack after several months of drug withdrawal. Four patients underwent revascularization procedures after normalization of their hormonal conditions in 307 Hospital of PLA and their neurologic status has remained stable during follow-up. Conclusions: Compared with classical moyamoya disease, moyamoya syndrome associated Graves’ disease more commonly presented asymmetric stenosis or occlusion and PCA lesions. Cerebrovascular hemodynamic changes attributable to thyrotoxicosis might be responsible for ischemic attack and further studies are required to verify this hypothesis.

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.

Doppler features of distal internal carotid artery stenosis.

Doppler features of distal internal carotid artery stenosis.

Variability in measurement of specific parameters for carotid duplex examination.

The variability of four carotid artery frequency parameters used for classifying disease with duplex scanning was prospectively studied. Forty-eight patients (94 patent carotid arteries) were each examined by two technologists. Measured parameters were the peak systolic frequency (PSF) and the first zero slope from the common carotid artery, and the PSF and end diastolic frequency (EDF) from the internal carotid artery. Measurements from all the examinations were made twice by each technologist. Interobserver, intraobserver, and interpatient variability in measurement of the first zero slope was so great that we have abandoned its use. Measurement of variability for PSF and EDF was much less (correlation coefficients 0.68 to 0.92). These parameters were measured with sufficient precision to warrant their continued use for important decision steps in classifying carotid artery disease. Interpatient differences in PSF sufficient to cause disagreement regarding the hemodynamic significance of carotid disease occurred in only three instances. In each of these cases the differences were due to examination technique (failure to identify a very distal internal carotid artery stenosis, difficulty distinguishing between a kink and a stenosis, and failure to recognize an improper Doppler angle). We conclude that the variability of PSF and EDF is within clinically acceptable levels and is mainly due to examination technique rather than measurement of waveform parameters or changes in patient hemodynamics.