Characteristics of Peri-Internal Carotid Artery Bifurcation Aneurysms According to a New Anatomic Classification: How to Overcome Difficulties in the Microsurgical Treatment of Posteroinferiorly Projecting Carotid-A1 Junctional Aneurysms.

OBJECTIVE: Based on our clinical experience, posteroinferiorly projecting carotid-A1 junctional aneurysms are often difficult to treat microsurgically. Our objective was to classify peri-internal carotid artery (ICA) bifurcation aneurysms according to their location and analyze their characteristics. METHODS: From January 2008 to October 2017, microsurgical or endovascular treatment of 6777 aneurysms were performed at our hospital. We identified 199 peri-ICA bifurcation aneurysms (2.94%) classified into true ICA bifurcation aneurysm, carotid-A1 junctional aneurysm, and carotid-M1 junctional aneurysm according to the anatomic location. Medical records including patient characteristics, aneurysm location, surgical method, any neurologic deficits, clinical outcomes, medical history, and radiologic findings were retrospectively reviewed. The anatomic position of the aneurysm was defined from the virtual surgical, anteroposterior, and lateral views, and the degree of agreement was calculated. RESULTS: There were 103 true ICA bifurcation aneurysms, 92 carotid-A1 junctional aneurysms, and 4 carotid-M1 junctional aneurysms. Carotid-A1 junctional aneurysms tended to be smaller, elongated, and more often posteroinferiorly projecting than true ICA bifurcation aneurysms. Posteroinferiorly projecting carotid-A1 junctional aneurysms tended to require complex aneurysm surgery. The virtual surgical view had an almost perfect degree of agreement with the actual surgical view. CONCLUSIONS: The characteristics of carotid-A1 junctional aneurysms and true ICA bifurcation aneurysms differ. In particular, carotid-A1 junctional aneurysms tend to have a posteroinferior projection and that causes difficulty in surgical treatment. We recommend the virtual surgical view for preoperative planning. Furthermore, an adequate Sylvian fissure opening and a strategic approach using appropriate devices to inspect blind spots should be considered for a successful treatment outcome.

TIA patients with higher ABCD3-I scores are prone to a higher incidence of intracranial stenosis, unstable carotid plaques and multiple-vessel involvement.

The ABCD3-I criteria have proved to be effective for use in regular clinical practice to assist in transient ischemic attack (TIA) risk stratification and treatment. In this prospective study we aimed to explore the relationships between risk stratification and arterial stenosis location, carotid plaque morphology and vessel involvement in 90 TIA patients, stratifying risk by ABCD3-I scores. Clinical variables such as total cholesterol, triglyceride, low-density lipoprotein cholesterol, glycosylated hemoglobin, homocysteine and high-sensitive C-reactive protein levels were recorded. The endpoint was subsequent stroke at seven-day follow-up. Ninety patients were divided into three risk groups on the basis of their ABCD3-I scores. The results revealed that patients with higher ABCD3-I scores showed a higher occurrence of intracranial stenosis (P < 0.05), less organized carotid plaques (P < 0.05) and multiple-vessel involvement (P < 0.05).

[TIMMA: Ultrasonographic scale of carotid atherosclerosis by vascular neurologists]. / TIMMA : échelle échographique de la surcharge athéromateuse en carotide pratiquée par des neurologues vasculaires.

BACKGROUND: Carotid atherosclerosis is a powerful predictive factor of vascular risk at the individual patient level. Ultrasonography is a reference technique for the evaluation of this condition. However, its use in common practice remains difficult due to a lack of standardization and inter-operator variability. We present a new and simple technique for the assessment of carotid atherosclerosis; and evaluate the ability of vascular neurologists to obtain results consistent with those of an expert in vascular ultrasound. MATERIAL AND METHODS: The TIMMA scale is an acronym for the five classes of carotid atherosclerosis in French, VIMMA in English: very important, important, moderate, minimal and absent. Combined, the first two classes make up the group "significant atheroma" and the last three classes make up the group "no significant atheroma". This scale was evaluated in 38 patients (76 carotid arteries) suffering from ischemic stroke or transient ischemic attack by five operators who are competent in carotid echocardiography: one TIMMA-trained (40 hours of training) vascular neurologist physician (VNP), three VNPs informed on the measurement method (1 hour of information) and one specialized vascular physician (SVP) who was considered to be the reference examiner. We evaluated the concordance between the VNPs and the SVP in classifying patients, firstly into the significant or not atheroma group and, secondly, into the five TIMMA classes. RESULTS: The evaluation of the two-group clustering scale found a concordance between the informed VNPs and the SVP on 76 carotid arteries of 86% (kappa=0.7) and between the trained VNP and the SVP on 58 carotid arteries of 90% (kappa=0.8). The positive and negative predictive values for significant atheroma diagnosis were 100% and 81%, respectively, for the informed VNPs, and 100% and 80% for the trained VNP. The evaluation of the Five-Class Scale showed a concordance between the informed VNPs and the SVP of 46% (kappa=0.3), and between the trained VNP and the SVP of 74% (kappa=0.7). CONCLUSION: TIMMA allows VNPs who are competent in carotid ultrasonography to reproducibly identify subjects with significant carotid atheroma. The contribution of this scale to the determination of cardiovascular risk should be evaluated.

[On the classification of large and giant paraclinoid internal carotid artery aneurysms]. / K voprosu o klassifikatsii bol'shikh i gigantskikh paraklinoidnykh anevrizm vnutrennikh sonnykh arterii.

Large and giant intradural ICA aneurysms or the so-called paraclinoid aneurysms are a surgical challenge requiring high qualification of the neurosurgeon. Despite numerous publications on this topic, there is still no generally accepted classification of paraclinoid aneurysms. In this paper, we analyzed the definitions and classifications of paraclinoid aneurysms, which were available in the medical literature. The paper presents our own surgical classification of paraclinoid ICA aneurysms, which has been developed by Prof. Sh.Sh. Eliava and co-authors at the Burdenko Neurosurgical Institute. The classification is based on the aneurysm neck position relative to the ICA wall, aneurysm dome direction, and type of aneurysm clipping.

Current Understanding of Dolichoarteriopathies of the Internal Carotid Artery: A Review.

Dolichoarteriopathies of the internal carotid artery (DICAs) are not uncommon, and although several studies have investigated DICAs, several questions regarding the etiology and best management course for DICAs remain unanswered. It is also difficult to correlate the occurrence of DICAs with the onset of clinical symptoms. Therefore, we surveyed the literature in PubMed and performed a review of DICAs to offer a comprehensive picture of our understanding of DICAs. We found that DICAs can be classified into three types, specifically tortuous, coiling and kinking, and are not associated with atherosclerotic risk factors. Cerebral hemodynamic changes are mainly associated with the degree of bending of DICAs. DICAs can result in symptoms of the brain and eyes due to insufficient blood supply and can co-occur with a pulsatile cervical mass, a pharyngeal bulge and pulsation. The diagnostic tools for the assessment of DICAs include Doppler ultrasonography, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA), and although DSA remains the gold standard, Doppler ultrasonography is a convenient method that provides useful data for the morphological evaluation of DICAs. CTA and MRA are efficient methods for detecting the morphology of the cervical segment of DICAs. Some DICAs should be treated surgically based on certain indications, and several methods, including correcting the bending or shortening of DICAs, have been developed for the treatment of DICAs. The appropriate treatment of DICAs results in good outcomes and is associated with low morbidity and mortality rates. However, despite the success of surgical reconstruction, an appropriate therapeutic treatment remains a subject of numerous debates due to the lack of multicentric, randomized, prospective studies.

Distinctive patterns on CT angiography characterize acute internal carotid artery occlusion subtypes.

Noninvasive computed tomography angiography (CTA) is widely used in acute ischemic stroke, even for diagnosing various internal carotid artery (ICA) occlusion sites, which often need cerebral digital subtraction angiography (DSA) confirmation. We evaluated whether clinical outcomes vary depending on the DSA-based occlusion sites and explored correlating features on baseline CTA that predict DSA-based occlusion site.We analyzed consecutive patients with acute ICA occlusion who underwent DSA and CTA. Occlusion site was classified into cervical, cavernous, petrous, and carotid terminus segments by DSA confirmation. Clinical and radiological features associated with poor outcome at 3 months (3-6 of modified Rankin scale) were analyzed. Baseline CTA findings were categorized according to carotid occlusive shape (stump, spearhead, and streak), presence of cervical calcification, Willisian occlusive patterns (T-type, L-type, and I-type), and status of leptomeningeal collaterals (LMC).We identified 49 patients with occlusions in the cervical (n = 17), cavernous (n = 22), and carotid terminus (n = 10) portions: initial NIH Stroke Scale (11.4 ±â€Š4.2 vs 16.1 ±â€Š3.7 vs 18.2 ±â€Š5.1; P < 0.001), stroke volume (27.9 ±â€Š29.6 vs 127.4 ±â€Š112.6 vs 260.3 ±â€Š151.8 mL; P < 0.001), and poor outcome (23.5 vs 77.3 vs 90.0%; P < 0.001). Cervical portion occlusion was characterized as rounded stump (82.4%) with calcification (52.9%) and fair LMC (94.1%); cavernous as spearhead occlusion (68.2%) with fair LMC (86.3%) and no calcification (95.5%); and terminus as streak-like occlusive pattern (60.0%) with poor LMC (60.0%), and no calcification (100%) on CTA.Our study indicates that acute ICA occlusion can be subtyped into cervical, cavernous, and terminus. Distinctive findings on initial CTA can help differentiate ICA-occlusion subtypes with specific characteristics.

Comparison of magnetic resonance imaging mismatch criteria to select patients for endovascular stroke therapy.

BACKGROUND AND PURPOSE: The Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution 2 (DEFUSE 2) study has shown that clinical response to endovascular reperfusion differs between patients with and without perfusion-diffusion (perfusion-weighted imaging-diffusion-weighted imaging, PWI-DWI) mismatch: patients with mismatch have a favorable clinical response to reperfusion, whereas patients without mismatch do not. This study examined whether alternative mismatch criteria can also differentiate patients according to their response to reperfusion. METHODS: Patients from the DEFUSE 2 study were categorized according to vessel occlusion on magnetic resonance angiography (MRA) and DWI lesion volume criteria (MRA-DWI mismatch) and symptom severity and DWI criteria (clinical-DWI mismatch). Favorable clinical response was defined as an improvement of ≥8 points on the National Institutes of Health Stroke Scale (NIHSS) by day 30 or an NIHSS score of ≤1 at day 30. We assessed, for each set of criteria, whether the association between reperfusion and favorable clinical response differed according to mismatch status. RESULTS: A differential response to reperfusion was observed between patients with and without MRA-DWI mismatch defined as an internal carotid artery or M1 occlusion and a DWI lesion<50 mL. Reperfusion was associated with good functional outcome in patients who met these MRA-DWI mismatch criteria (odds ratio [OR], 8.5; 95% confidence interval [CI], 2.3-31.3), whereas no association was observed in patients who did not meet these criteria (OR, 0.5; 95% CI, 0.08-3.1; P for difference between the odds, 0.01). No differential response to reperfusion was observed with other variations of the MRA-DWI or clinical-DWI mismatch criteria. CONCLUSIONS: The MRA-DWI mismatch is a promising alternative to DEFUSE 2's PWI-DWI mismatch for patient selection in endovascular stroke trials.

Toward an endovascular internal carotid artery classification system.

SUMMARY: Does the world need another ICA classification scheme? We believe so. The purpose of proposed angiography-driven classification is to optimize description of the carotid artery from the endovascular perspective. A review of existing, predominantly surgically-driven classifications is performed, and a new scheme, based on the study of NYU aneurysm angiographic and cross-sectional databases is proposed. Seven segments - cervical, petrous, cavernous, paraophthlamic, posterior communicating, choroidal, and terminus - are named. This nomenclature recognizes intrinsic uncertainty in precise angiographic and cross-sectional localization of aneurysms adjacent to the dural rings, regarding all lesions distal to the cavernous segment as potentially intradural. Rather than subdividing various transitional, ophthalmic, and hypophyseal aneurysm subtypes, as necessitated by their varied surgical approaches and risks, the proposed classification emphasizes their common endovascular treatment features, while recognizing that many complex, trans-segmental, and fusiform aneurysms not readily classifiable into presently available, saccular aneurysm-driven schemes, are being increasingly addressed by endovascular means. We believe this classification may find utility in standardizing nomenclature for outcome tracking, treatment trials and physician communication.

Imaging of a case of benign carotidynia with ultrasound, MRI and PET-CT.

We present a case of carotidynia that we believe supports its classification as a distinct inflammatory disease entity. Doppler sonography and cervical magnetic resonance imaging are appropriate imaging modalities for diagnosing presumed carotidynia.

In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components.

BACKGROUND: Atherosclerotic plaques in carotid arteries can be characterized in-vivo by multicontrast cardiovascular magnetic resonance (CMR), which has been thoroughly validated with histology. However, the non-quantitative nature of multicontrast CMR and the need for extensive post-acquisition interpretation limit the widespread clinical application of in-vivo CMR plaque characterization. Quantitative T2 mapping is a promising alternative since it can provide absolute physical measurements of plaque components that can be standardized among different CMR systems and widely adopted in multi-centre studies. The purpose of this study was to investigate the use of in-vivo T2 mapping for atherosclerotic plaque characterization by performing American Heart Association (AHA) plaque type classification, segmenting carotid T2 maps and measuring in-vivo T2 values of plaque components. METHODS: The carotid arteries of 15 atherosclerotic patients (11 males, 71 ± 10 years) were imaged at 3 T using the conventional multicontrast protocol and Multiple-Spin-Echo (Multi-SE). T2 maps of carotid arteries were generated by mono-exponential fitting to the series of images acquired by Multi-SE using nonlinear least-squares regression. Two reviewers independently classified carotid plaque types following the CMR-modified AHA scheme, one using multicontrast CMR and the other using T2 maps and time-of-flight (TOF) angiography. A semi-automated method based on Bayes classifiers segmented the T2 maps of carotid arteries into 4 classes: calcification, lipid-rich necrotic core (LRNC), fibrous tissue and recent IPH. Mean ± SD of the T2 values of voxels classified as LRNC, fibrous tissue and recent IPH were calculated. RESULTS: In 37 images of carotid arteries from 15 patients, AHA plaque type classified by multicontrast CMR and by T2 maps (+ TOF) showed good agreement (76% of matching classifications and Cohen's κ = 0.68). The T2 maps of 14 normal arteries were used to measure T2 of tunica intima and media (T2 = 54 ± 13 ms). From 11865 voxels in the T2 maps of 15 arteries with advanced atherosclerosis, 2394 voxels were classified by the segmentation algorithm as LRNC (T2 = 37 ± 5 ms) and 7511 voxels as fibrous tissue (T2 = 56 ± 9 ms); 192 voxels were identified as calcification and one recent IPH (236 voxels, T2 = 107 ± 25 ms) was detected on T2 maps and confirmed by multicontrast CMR. CONCLUSIONS: This carotid CMR study shows the potential of in-vivo T2 mapping for atherosclerotic plaque characterization. Agreement between AHA plaque types classified by T2 maps (+TOF) and by conventional multicontrast CMR was good, and T2 measured in-vivo in LRNC, fibrous tissue and recent IPH demonstrated the ability to discriminate plaque components on T2 maps.

Common carotid flow velocity is associated with cognition in older adults.

AIMS: To assess the relationship between carotid flow velocity and cognitive impairment in patients with mild-moderate (<50%) carotid artery disease. METHODS: We studied 407 participants with available carotid ultrasound and cognitive measures. We related peak systolic velocity (PSV) and end diastolic velocity (EDV) of internal carotid artery (ICA) and common carotid artery (CCA) and intimal medial thickness (IMT) to Mini Mental State Examination (MMSE), Clock Draw Test (CDT), Activities of Daily Living Scale (ADL)and Montreal Cognitive Assessment (MoCA). RESULTS: EDV of CCA was significantly different in higher and lower MoCA (MMSE) groups. Multiple regression analysis demonstrated that lower EDV was significantly associated with lower MoCA (+0.459 per standard deviation (SD), p<0. 01 for the left; +0.539 per SD, p<0. 01 for the right) and CDT (odds ratio (OR) 0.093, p< 0.05 for the left; OR) 0.120, p<0. 01 for the right) scores. PSV of left CCA (-0.205 per SD, p<0.05) and IMT (+42.536 per SD, p< 0.001) were associated with ADL. PSV of right CCA was associated with MMSE (+0.081 per SD, p<0.001). No significant relationship between ICA flow velocity and cognitive performance was observed. CONCLUSIONS: Our preliminary data show that common carotid artery flow velocity was associated with cognitive performance.

Medical decision-making system of ultrasound carotid artery intima-media thickness using neural networks.

The objective of this work is to develop and implement a medical decision-making system for an automated diagnosis and classification of ultrasound carotid artery images. The proposed method categorizes the subjects into normal, cerebrovascular, and cardiovascular diseases. Two contours are extracted for each and every preprocessed ultrasound carotid artery image. Two types of contour extraction techniques and multilayer back propagation network (MBPN) system have been developed for classifying carotid artery categories. The results obtained show that MBPN system provides higher classification efficiency, with minimum training and testing time. The outputs of decision support system are validated with medical expert to measure the actual efficiency. MBPN system with contour extraction algorithms and preprocessing scheme helps in developing medical decision-making system for ultrasound carotid artery images. It can be used as secondary observer in clinical decision making.

Classification for carotid artery stenting complications: manifestation, management, and prevention.

Carotid artery stenting is a rapidly evolving method for treating carotid artery disease. Various intraprocedural and postprocedural complications have been reported in the literature. However, the absence of a unified classification scheme for these complications makes it difficult, if not impossible, to study their precise incidence, predictors, and management. The aim of this article is to propose the first joint classification of periprocedural complications, to analyze their incidence and etiology, and suggest possible ways to manage and prevent them. This classification is intended to be used as a common platform for prompt recognition, evaluation, treatment, and universal study of the complications during carotid stenting procedures. For this purpose, the opinions of the major experts on carotid interventions worldwide were merged with all the available information reported in the English-language literature to present as accurately as possible the management and prevention of carotid stenting complications according to this proposed classification.

Atherosclerotic carotid vulnerable plaque and subsequent stroke: a high-resolution MRI study.

BACKGROUND: High-resolution contrast-enhanced magnetic resonance imaging (CEMRI) has been proven to be an effective tool for the identification of carotid atherosclerotic vulnerable plaque, such as a large lipid core and thin fibrous cap. The aim of this study was to evaluate the relationship between carotid plaque characteristics and the types of stroke in patients who had carotid artery (CA) stenosis > or =50%. METHODS: 102 consecutive subjects (mean age 67.2 +/- 10.2 years; 73 males) who initially had ischemic stroke or asymptomatic CA stenosis from 50 to 100% diagnosed by ultrasound were included in this study. Carotid CEMRI, brain MRI and magnetic resonance angiography were performed to understand the infarct patterns and to exclude intracranial artery stenosis. The modified American Heart Association (AHA) plaque classification was used in our study. RESULTS: Our study demonstrated that 45 patients had CA stroke, and 55 patients had lacunar and asymptomatic lesions. The majority of patients had AHA classification type IV-V and VI which presented as vulnerable plaques. Of 63 patients with mild to moderate stenosis (< or =70%), 44 (69.8%) had type IV-V vulnerable plaques, which was significantly higher than those of patients with severe stenosis (>70%; p < 0.001). In CA stroke, the number of patients with a thin or ruptured fibrous cap was twice that of those with a thick and intact fibrous cap. CONCLUSIONS: CEMRI may have important applications in clinical risk evaluations in CA atherosclerosis. Physicians ought to recognize that different types of stroke should be identified by brain MRI detection before invasive therapies.

A clinical classification system for aberrant internal carotid arteries.

OBJECTIVES/HYPOTHESIS: Pronounced anatomic variations of the extracranial internal carotid artery (ICA) can be found in 5% to 6% of the general population. An aberrant ICA is at risk of injury during routine pharyngeal procedures if the vessel is placed into close relationship with the pharyngeal wall. The objective was to highlight the impact of parapharyngeal ICA aberrations and to analyze the clinical usefulness of the current anatomic classification system of these anomalies. STUDY DESIGN: Prospective quality assessment study in an academic tertiary care medical center. METHODS: A systematic clinicoradiological follow-up study was performed over a period of 18 months. The ICA's course was classified according to Weibel and Fields in 21 consecutive patients with 35 pronounced parapharyngeal ICA aberrations. The vessels' minimum distance to the pharyngeal wall and the corresponding pharyngeal level was analyzed. RESULTS: Tortuosity was found in 13, kinking in 18, and coiling in 4 aberrant ICAs. The vessel's minimum distance to the pharyngeal wall ranged from 0.8 to 17.9 mm (mean, 7.0 mm), but the currently used anatomic classification was inadequate to determine the risk potential for ICA injury in the given cases. We propose a clinicoradiological classification system, which considers the vessel's relation to the pharyngeal wall. CONCLUSIONS: Parapharyngeal ICA aberrations are common and probably under-appreciated anatomic variations. The awareness of these anomalies is essential for clinicians. Since the current anatomic classification is insufficient to outline patients with an increased risk of ICA injury, a clinicoradiological graduation of cervical ICA aberrations may be of practical benefit.

Total occlusion of the common carotid artery: a modified classification and its relation to clinical status.

To investigate the hemodynamics and clinical presentation of common carotid artery occlusion (CCAO), we reviewed 6,415 patients with suspected carotid artery disease in whom a color Duplex imaging (CDI) examination was performed. According to distal vessel patency, the following CDI classification of CCAO was adopted: type I (patent both distal vessels); type II (isolated patency of external carotid artery); type III (isolated patency of internal carotid artery); and type IV (both distal vessels occluded). Thirty-five (0.5%) cases met the CDI criteria for CCAO. Twenty-nine of those (83%) had at least one patent distal vessel. Ten patients (29%) presented with stroke, 20 (57%) with transient ischemic attacks (TIAs) and five (14%) were asymptomatic. The incidence of stroke was higher in type IV (50%) vs. type II (30%) and in type II vs. type I (10%) lesions. Similarly, TIAs presented more often in type II (67%) and IV (50%) vs. in type I (40%) lesions (p = 0.002). Retrograde flow in the ophthalmic artery and concomitant severe contralateral carotid artery stenosis were more often related with type II and IV lesions (p = 0.02 and 0.04, respectively). CCAO is usually accompanied by patent distal vessel(s). The proposed CCAO classification correlates well with the patients' clinical status and may help to better clarify the outcome of this rare entity. Among the main arteries of the developed collateral circulation, only the flow direction in the ophthalmic artery may be of clinical value.