Ipsilateral Carotid Research Articles

Detection and Differentiation of Dural Arteriovenous Fistulas in the Transverse Sinus/Sigmoid Sinus and Cavernous Sinus Using Carotid Ultrasound: Importance of Evaluation of the Occipital Artery.

Dural arteriovenous fistula (DAVFs) in the transverse sinus (TS)/sigmoid sinus (SS) and cavernous sinus (CS) are observed frequently in the clinic. This study aimed to detect DAVFs with ultrasound and compare carotid ultrasound findings between these conditions. We retrospectively reviewed 26 patients with either a TS/SS DAVF or a CS DAVF who were admitted to our hospital for evaluation of DAVFs from 2014 to 2018. The shunt site decision was made by neuroendovascular experts, whereas carotid ultrasound examinations were performed by ultrasound specialists. The flow velocity of the ipsilateral external carotid artery was reviewed in all 26 patients, whereas that of the occipital artery (OA) was examined in 20 patients. Blood flow velocities were compared between the TS/SS DAVF and CS DAVF groups. The study included 18 patients with a TS/SS DAVF (11 women and 7 men; mean age ± SD, 65.3 ± 18.6 years) and 8 patients with a CS DAVF (7 women and 1 man; mean age, 70.4 ± 9.3 years). Evaluations of feeder arteries on cerebral angiography showed that all patients had dural branches from the internal carotid and middle meningeal arteries as feeders of CS DAVFs, whereas the OA was the major feeder source of all TS/SS DAVF cases. The end-diastolic velocity (EDV) of the external carotid artery was significantly higher in patients with a TS/SS DAVF compared with those with a CS DAVF (P = .004). The EDV of the OA was significantly elevated in TS/SS DAVF cases compared with CS DAVF cases (P < .001). Duplex ultrasound parameters are significantly different between patients with TS/SS and CS DAVFs. An increased EDV of the OA can predict the presence of a TS/SS DAVF.

Improvement in gait function after carotid endarterectomy is associated with postoperative recovery in perfusion and neurotransmitter receptor function in the motor-related cerebral cortex: a 123I-iomazenil SPECT study.

Carotid endarterectomy (CEA) often restores cerebral perfusion and neurotransmitter receptor function, which is seen on early and late images, respectively, on brain I-iomazenil single-photon emission computed tomography (SPECT). The reliability of gait-related parameters obtained using a triaxial accelerometer, a portable device for gait assessment, has been confirmed with test-retest measurements. The purpose of the present prospective cohort study was to determine whether improvement in gait function after CEA is associated with postoperative recovery in perfusion and neurotransmitter receptor function in the motor-related cerebral cortex. Gait testing using a triaxial accelerometer was performed preoperatively and 6 months postoperatively in 64 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%). I-iomazenil SPECT was also performed with scanning within 30 min (early images) and at 180 min (late images) after tracer administration before and after surgery. SPECT data were analyzed using a three-dimensional stereotactic surface projection, and motor (Brodmann 4) and premotor (Brodmann 6) cortexes in each hemisphere were combined and defined as the motor-related cortex. Based on preoperative and postoperative gait testing, seven patients (11%) showed postoperative improved gait. Logistic regression analysis revealed that postoperative increase in I-iomazenil uptake in the motor-related cortex ipsilateral to surgery on early [95% confidence interval (CI), 4.32-365.21; P = 0.0477) or late (95% CI, 9.45-1572.57; P = 0.0173) images was an independent predictor of postoperative improved gait. Improvement in gait function after CEA is associated with postoperative recovery in perfusion and neurotransmitter receptor function in the motor-related cerebral cortex.

Ipsilateral Nonstenotic Carotid Disease in Minor Ischemic Stroke: an Exploratory Analysis of The POINT Randomized Clinical Trial

Background and aimIpsilateral nonstenotic carotid disease is increasingly recognized as an etiology of ischemic stroke, however tailored treatment strategies are lacking. We aimed to examine clinical characteristics and treatment effects in patients with minor ischemic stroke associated with ipsilateral nonstenotic carotid disease in the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial. MethodsWe performed an exploratory analysis of the interaction of the treatment effects of aspirin plus clopidogrel versus aspirin monotherapy, stratified by presence of ipsilateral nonstenotic carotid disease in patients with minor ischemic stroke in the POINT trial. ResultsFor this exploratory analysis, 167 patients presenting with ischemic stroke and ipsilateral nonstenotic carotid disease, defined as 1%-49% carotid stenosis ipsilateral to the corresponding territory of ischemic stroke, and 833 patients no carotid disease were included. Compared to patients with no carotid disease, patients with ipsilateral nonstenotic carotid disease were older (68.5 ± 11.3 years versus 61.3 ± 12.8 years; P < 0.001), and had a higher prevalence of hypertension (76.6% versus 59.2%, P < 0.001), ischemic heart disease (13.8% versus 5.4%, P < 0.001), and tobacco use (past: 34.1% versus 25.2%, P = 0.005; present: 27.5% versus 22.8%, P = 0.005). 5.4% of patients with ipsilateral nonstenotic carotid disease had recurrent ischemic stroke within 14 days. Patients receiving dual antiplatelet therapy had a numerical reduction in recurrent ischemic stroke compared to patients receiving aspirin monotherapy, however the exploratory analysis was underpowered to detect a statistically significant difference in treatment effect (HR 0.50, 95% CI 0.18-1.40, P = 0.19). ConclusionPatients with minor ischemic stroke and ipsilateral nonstenotic carotid disease had a high risk of early stroke recurrence in the POINT trial. Dual antiplatelet therapy provided a non-statistically significant reduction in recurrent ischemic stroke with no difference in safety outcomes compared to aspirin monotherapy. Further study is needed to determine if early and short duration dual antiplatelet therapy is beneficial for all patients with ipsilateral nonstenotic carotid disease.

Comparison of the Effectiveness of Ring-Stripping Retrograde Endarterectomy and Carotid Artery Crossover Bypass in the Treatment of Patients with Symptomatic Riles Type 1A Common Carotid Artery Occlusion

Objective: The surgical procedure most appropriate for treating symptomatic Riles type 1A common carotid artery occlusion (CCAO) is unclear. This study compares the effects of ring-stripping retrograde endarterectomy (RSRE) and carotid artery crossover bypass (CACB) on cerebral perfusion improvement in patients with symptomatic Riles type 1A CCAO. Methods: We conducted a retrospective analysis of symptomatic Riles type 1A CCAO patients treated at our centre. Postoperative improvements in the ipsilateral internal carotid artery (ICA) flow rate, ipsilateral cerebral blood perfusion (CBP) and the stroke recurrence rate were compared between patients who underwent RSRE and those who underwent CACB. Results: A total of 20 CCAO patients were surgically treated at our centre from 2011 to 2018. Nine of these patients underwent RSRE, and eleven underwent CACB. No significant differences were identified between the groups in the ipsilateral blood flow rate of the ICA immediately after surgery and the ipsilateral-to-contralateral mean transit time ratios 1 day after surgery. However, the flow rate in the ICA was significantly higher in the RSRE group than in the CACB group 1 year after surgery (135.44 ± 19.22 ml/min vs. 116.36 ± 17.70 ml/min, p = 0.033). For CBP, the ipsilateral-to-contralateral mean transit time ratios were significantly lower in RSRE patients than in CACB patients 1 year after surgery (1.005 ± 0.052 vs. 1.064 ± 0.066, p = 0.044). In addition, the postoperative modified Rankin scale (mRS) score at the latest follow-up point (p = 0.884) and the stroke recurrence rate during the follow-up (88.9% vs. 90.9%, p > 0.999) were not significantly different between the two groups. Conclusions: Although the postoperative mRS score and the stroke recurrence rate were not significantly different between RSRE and CACB patients, compared to CACB, RSRE was better for improving the ipsilateral ICA flow rate and cerebral perfusion in symptomatic Riles type 1A CCAO patients.

The endoscopic supraorbital translaminar approach: a technical note.

Resection of lesions located within the third ventricle presents a surgical challenge. Several approaches have been developed in an attempt to obtain maximal resection, while minimizing brain retraction. In this work, we assess the surgical exposure and maneuverability of the endoscopic supraorbital translaminar approach (ESTA), a potential alternative to fenestrate the lamina terminalis and approach the third ventricle by using the endoscope through a keyhole supraorbital-eyebrow craniotomy. Five cadaveric heads were used to assess the corridor depth, area of exposure, and viewing angles offered by the ESTA. One additional utilized specimen provided a stepwise dissection of the approach. The ESTA was successfully performed in all specimens. Depth of the surgical corridor from the craniotomy to the ipsilateral internal carotid artery (ICA), lamina terminalis, and contralateral carotid were 70.7 ± 2.9mm, 73.2 ± 2.9mm, and 78.9 ± 4.1mm, respectively. Viewing angle referenced to the ipsilateral ICA was 6.5 ± 4.2°, while the viewing angle for the lamina terminalis was 25.8 ± 4.3°. The surgical exposure provided by the ESTA was 1655 ± 255mm2. The ESTA provides a wide surgical view of the lamina terminalis and may be potentially used to approach lesions located in the anterior third of the third ventricle. As a pure endoscopic approach, the ESTA requires minimal brain retraction, while affords good visualization of targeted lesions around the lamina terminalis. The ESTA uses an anterolateral approach and so provides a short and straightforward approach to these structures.

Prevalence of Non-Stenotic (

IntroductionNon-stenotic (<50%) carotid plaques have recently been recognized as a potential source of stroke. This meta-analysis aims to summarize the prevalence of non-stenotic carotid plaques in stroke patients in general and in patients with embolic stroke of undetermined source in particular. MethodsWe performed a comprehensive systematic review of the literature and meta-analysis on acute ischemic stroke patients in whom carotid imaging was performed using the MEDLINE, Embase and Cochrane database, including studies published up to December 2019. Keywords were "stroke”, “transient ischemic attack”, “carotid”, “plaque”, “atherosclerosis” and “disease”. Included studies had ≥10 patients with acute ischemic stroke and reported the prevalence of non-stenotic (<50%%stenosis) carotid plaques detected on any imaging modality. ResultsWe included forty-five studies (n = 18304 patients, 48.4% males, mean age 63.6 years) in our meta-analysis. Imaging modalities used were ultrasound (n = 26 studies), CT-angiography (n = 7), magnetic resonance-imaging (n = 8) and catheter angiography (n = 4). The overall prevalence of non-stenotic carotid plaques was 51% (95% CI: 43 - 59). 10 studies included mainly patients with embolic stroke of undetermined source (>50% of all patients). The pooled prevalence of non-stenotic carotid plaques in these studies was 55% (95% CI: 42 - 68). 23 studies explicitly reported ipsilateral non-stenotic carotid plaques, the pooled prevalence of which was 51% (95% CI: 45 - 59). ConclusionsIn this meta-analysis, non-stenotic carotid plaques were present in more than 50% of all acute ischemic stroke patients, with a slightly higher prevalence in ESUS patients. Given the potential role of non-stenotic carotid plaques in stroke etiology, particularly in ESUS, further research should aim to identify criteria that predict the stroke risk associated with non-stenotic carotid plaques.

Contrast enhanced ultrasound of carotid plaque in acute ischemic stroke (CUSCAS study).

Carotid atherosclerosis represents 8 to 15% of ischemic strokes in relation to the concept of "vulnerable" plaque. Contrast enhanced ultrasound (CEUS) can detect moving microbubbles within the plaque corresponding to neovessels that constitute "precursors" of vulnerable plaque and intraplaque hemorrhage. CEUS was not studied specifically in acute ischemic strokes. The aim of this study is to analyse the prevalence of CEUS carotid plaque ipsilateral at the ischemic stroke as well as the main characteristics of contrast-plaques. A single-centre prospective pilot study involving 33 consecutive patients with a stroke ≤10 days, diagnosed by an MRI with positive diffusion sequence and having a carotid plaque thickness ≥2.5mm with low or heterogeneous echogenicity, located in the ipsilateral carotid territory at the stroke. Plaque echogenicity was done by visual analysis and by measurement of the gray scale median (GSM). A transcranial Doppler monitoring was carried out in search of HITS. The contrast ultrasound was performed after 2.5 cc IV injection of SonoVue®. A video clip was recorded after injection which was used for interpretation by visual analysis in 3 grades, provided by two independent expert readers. The population consisted of 10 women and 23 men aged 73 on average. The topography of strokes in the carotid territory was located on the right in 11 (33%) cases and on the left in 22 (67%) cases. Seventeen patients had carotid stenosis between 0 and 49% according to the Nascet method and 16 patients had stenosis of 50 to 99%. The visual characterisation of the plaques had echolucent dominance (Type 1-2) in 18 cases and echogenic dominance (Type 3-4a) in 15 cases. Cardiovascular risk factors were common with no difference by sex. The inter-observer agreement of plaque enhancement was moderate in first reading (k=0.48) and excellent at consensus (k=0.91). Only one disagreement was found. Contrast agent enhancement of carotid plaque was observed in 11/32 patients, representing a prevalence of 34.4% - CI95% [17.9-50.9]. Variables associated with contrast plaque included the absence of antiplatelet drug (63.6% vs. 23.8%, P=0.05) and the presence of a regular edge on the plaque (91% vs. 48%, P=0.04). There was no difference in contrast enhancement for stenosis>or<50% in diameter and neither for the type of plaque. In a consecutive cohort of 33 patients, the prevalence of CEUS from an ipsilateral carotid plaque to a recent acute ischemic stroke was 34.4%. There was a statistically significant association between the contrast enhancement of the plaque and the absence of antiplatelet drug (P=0.05) and also the presence of a regular edge on the plaque (P=0.04). There was no correlation between plaque contrast and clinical and biological characteristics of patients or the presence of HITS.

Retinal arterial occlusion with multiple retinal emboli and carotid artery occlusion disease. Haemodynamic changes and pathways of embolism

ObjectiveTo introduce a special subgroup, retinal artery occlusion (RAO) with multiple emboli, which is highly associated with ipsilateral carotid artery occlusion disease (CAOD).Methods and analysisThis is a cohort study. Cases...

Cohort profile: BIOVASC-late, a prospective multicentred study of imaging and blood biomarkers of carotid plaque inflammation and risk of late vascular recurrence after non-severe stroke in Ireland

PurposeInflammation is important in stroke. Anti-inflammatory therapy reduces vascular events in coronary patients. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) identifies plaque inflammation-related metabolism. However, long-term prospective cohort studies investigating the association...

Relationship between stroke etiology and collateral status in anterior circulation large vessel occlusion

Background and purposeClinical outcome after mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke is influenced by the intracerebral collateral status. We tested the hypothesis that patients with preexisting ipsilateral extracranial carotid artery stenosis (CAS) would have a better collateral status compared to non-CAS patients. Additionally, we evaluated MT-related adverse events and outcome for both groups.MethodsOver a 7-year period, we identified all consecutive anterior circulation MT patients (excluding extracranial carotid artery occlusion and dissection). Patients were grouped into those with CAS ≥ 50% according to the NASCET criteria and those without significant carotid stenosis (non-CAS). Collateral status was rated on pre-treatment CT- or MR-angiography according to the Tan Score. Furthermore, we assessed postinterventional infarct size, adverse events and functional outcome at 90 days.ResultsWe studied 281 LVO stroke patients, comprising 46 (16.4%) with underlying CAS ≥ 50%. Compared to non-CAS stroke patients (n = 235), patients with CAS-related stroke more often had favorable collaterals (76.1% vs. 46.0%). Recanalization rates were comparable between both groups. LVO stroke patients with underlying CAS more frequently had adverse events after MT (19.6% vs. 6.4%). Preexisting CAS was an independent predictor for favorable collateral status in multivariable models (Odds ratio: 3.3, p = 0.002), but post-interventional infarct size and functional 90-day outcome were not different between CAS and non-CAS patients.ConclusionsPreexisting CAS ≥ 50% was associated with better collateral status in LVO stroke patients. However, functional 90-day outcome was independent from CAS, which could be related to a higher rate of adverse events.

Clinical study of stent forming for symptomatic internal carotid artery stenosis.

Stroke is one of the diseases that seriously threaten the survival and health of human beings. In Europe and the United States, stroke is the second leading cause of death after heart disease and tumors.[1] Stroke is also one of the fatal diseases in Asian countries. On average, about 1.5 million new stroke patients are added each year in China, and the incidence of stroke is increasing year by year. About 80% of all stroke patients are ischemic stroke, and symptomatic internal carotid atherosclerotic stenosis is another important cause of ischemic stroke. Ipsilateral carotid stenosis ≥50% increases the incidence of transient cerebral ischemia and stroke in the carotid artery region by 10% to 15%, and is also closely related to the recurrence of acute and long-term stroke in patients.[2] Therefore, the clinical application and efficacy of carotid stenting in patients with symptomatic internal carotid artery stenosis are analyzed and evaluated to provide a basis for the selection of clinical treatment options.The clinical data of patients with symptomatic carotid stenosis who underwent carotid stenting and the clinical data of conservative treatment of patients with symptomatic carotid stenosis were retrospectively analyzed, and the carotid stenosis rate, symptoms, and National Institute of Health stroke scale where compared before and after surgery. And activities of daily living score. Because the control group treatment method in this article is completely free for patients to choose, and belongs to a retrospective analysis, the results suggest that it can provide a high-quality treatment approach for the treatment of patients with symptomatic carotid stenosis, without causing any harm to the patient, So no ethical approval is needed, and no patient informed consent is required.In recent years, with the continuous advancement of science and technology and new stent materials, intravascular interventional technology has developed rapidly. In continuous clinical practice and research, the safety and effectiveness of stent technology have also been gradually improved. Arterial stenting has gradually become an important method for the treatment of atherosclerotic carotid stenosis. This technique can not only improve the symptoms and prognosis of patients with symptomatic internal carotid stenosis, but also prevent the occurrence of ischemic events. The promotion of this technology has the effect of reducing disability and mortality.The alternative therapy of drug therapy, namely arterial stent implantation, has become a new way to treat atherosclerotic stroke. This treatment technology can quickly relieve the abnormal hemodynamics of distal blood vessels caused by arterial stenosis, which is ischemic. Cerebrovascular disease provides new ideas for treatment. Carotid angioplasty and stenting for symptomatic internal carotid stenosis under a distal cerebral protection device is a safe and effective treatment.

Vasoreactivity of the Murine External Jugular Vein and Carotid Artery

Introduction: Impaired venous reactivity has potential to contribute to clinically significant pathologies such as arteriovenous fistula (AVF) maturation failure. Vascular segments commonly used in murine preclinical models of AVF include the carotid artery and external jugular vein. Detailed descriptions of isometric procedures to evaluate function of murine external jugular vein ex vivo have not been previously published. Objective: To establish isometric procedures to measure naive murine external jugular vein reactivity ex vivo. Methods: Vasomotor responses of external jugular veins and ipsilateral common carotid arteries from C57BL/6 mice were evaluated using isometric tension procedures. Results: External jugular veins developed tension (p < 0.05) to potassium chloride and U-46619, but not to phenylephrine, whereas common carotid arteries responded to all 3 agents (p < 0.05). While maximal responses to acetylcholine (ACh) were similar between the venous and arterial segments, the dose required to achieve this value was lower (p < 0.05) in the artery versus vein. Nitric oxide synthase inhibition attenuated (p < 0.05) but did not abolish ACh-evoked vasorelaxation in both vascular segments, whereas cyclooxygenase blockade had no effect. Endothelium-independent vasorelaxation to sodium nitroprusside was similar in the artery and vein. Conclusion: Vasorelaxation and vasocontraction can be reliably assessed in the external jugular vein in C57BL/6 mice using isometric procedures.

Prevalence and risk factors of symptomatic carotid stenosis in patients with recent transient ischaemic attack or ischaemic stroke in the Netherlands.

Literature on prevalence of symptomatic internal carotid artery stenosis is scarce and heterogeneous. Prevalence may have decreased in recent years due to improved management of cardiovascular risk factors. We aim to estimate current prevalence and identify risk factors of ipsilateral internal carotid artery stenosis in patients with recent hemispheric transient ischaemic attack or ischaemic stroke in the Netherlands. We included consecutive adult patients admitted to two large hospitals in the Netherlands in 2014 who suffered from amaurosis fugax, retinal ischaemia, transient ischaemic attack or ischaemic stroke in the vessel territory of the internal carotid artery. Primary outcome was presence of ipsilateral internal carotid artery stenosis (degree subdivided following NASCET criteria), as assessed with duplex ultrasonography, computed tomography angiography and/or magnetic resonance angiography. We used univariable and multivariable logistic regression to identify risk factors for the presence of a 50-100% internal carotid artery stenosis. We analysed 883 consecutive patients with recent transient ischaemic attack or ischaemic stroke. Of these, 110 (12.5%) had 50-99% ipsilateral internal carotid artery stenosis. Subgroup analyses showed higher prevalence of any degree of internal carotid artery stenosis for male sex and White patients. In adjusted analyses, higher age (odds ratio 1.4/10 years; 95% confidence interval 1.16-1.63), male sex (odds ratio 2.8; 95% confidence interval 1.83-4.19), retinal ischaemia (odds ratio 2.5; 95% confidence interval 1.32-4.76) and current smoking (odds ratio 1.8; 95% confidence interval 1.09-2.79) were statistically significant risk factors for 50-100% internal carotid artery stenosis. The prevalence of internal carotid artery stenosis seems to be lower in patients with recent transient ischaemic attack or ischaemic stroke than stated in previous studies. We found that higher age, male sex, White ethnicity, retinal ischaemia and current smoking were important risk factors for symptomatic internal carotid artery stenosis.

Carotid artery webs in embolic stroke of undetermined source with large intracranial vessel occlusion.

Whether carotid artery web can be considered as a potential source of arterial thromboembolism in ischemic stroke remains uncertain. In a large sample of individuals with large intracranial artery occlusion, we compared the prevalence of carotid artery webs between patients with and without embolic stroke of undetermined source. In a single-center study of consecutive patients with anterior circulation ischemic stroke referred for mechanical thrombectomy, the presence of carotid artery web was systematically assessed by two independent readers. Thereafter, its prevalence was compared between patients with and without embolic stroke of undetermined source. Among 466 patients of whom 12% were considered to have had an embolic stroke of undetermined source, ipsilateral carotid artery web was detected in 1.9% (confidence interval 95% = 0.7-3.1). Ipsilateral carotid artery web was more frequent in embolic stroke of undetermined source than in the rest of the sample (10.7% (confidence interval 95% = 2.7-18.7] vs. 0.7% (0-1.5), P < 0.001). This difference remains significant after adjustment for sex, age, and vascular risk factor (odds ratio: 12.5 (2.1-72), P = 0.005) or after exclusion of patients with any other bulb wall thickening (P = 0.025). In contrast, the difference of prevalence of contralateral carotid artery web between the two groups did not reach statistical significance (2.4% vs. 1.9%, P = 0.6). Our results suggest that the presence of a carotid artery web might be considered as a potential source of large intracranial artery embolism. Longitudinal studies are needed to assess the exact risk of recurrence associated with these lesions.

Control of retinal blood flow levels by selected combinations of cervical arterial ligations in rat

The effect of various combinations of cervical arterial ligations (Combinations) on retinal blood flow (RBF) levels is not known in rats. We hypothesized: 1) No artery exists between the Circle of Willis and the eye, 2) Selective Combinations enable varying RBF levels between normal and zero, 3) In certain Combinations, the capillary bed of the head participates in supplying the eye. Twenty-six Combinations were studied in one eye of 20 Long-Evans rats under general anesthesia. RBF was quantitatively evaluated with our published imaging methods based on direct measurements of venous diameter and blood velocity from the displacement of fluorescent microspheres over time. For each Combination, one or more RBF values (runs) were measured. Data were obtained from 59 runs (2.9 ± 2.7 runs/rat). Levels of RBF ranged from normal to zero. An artery between the Circle of Willis and the eye was excluded. With some Combinations, flow traversed the capillary bed. Combinations were consolidated into five Groups based on the blood flow paths remaining after the ligations. A mixed linear model accounting for multiple measurements in the same eye demonstrated an effect of Group on RBF (P < 0.0005). By major source of ocular blood supply, the trend of RBF levels was: ipsilateral carotid artery > contralateral carotid artery > ipsilateral distal internal carotid artery retrograde from Circle of Willis. The findings advanced knowledge of the sources of blood supply to the rat eye and demonstrated a method of selective cervical arterial ligations for varying RBF levels with potential to impact future retinal ischemia research.

A Rabbit Venous Interposition Model Mimicking Revascularization Surgery using Vein Grafts to Assess Intimal Hyperplasia under Arterial Blood Pressure.

Although vein grafts have been commonly used as autologous grafts in revascularization surgeries for ischemic diseases, the long-term patency remains poor because of the acceleration of intimal hyperplasia due to the exposure to arterial blood pressure. The present protocol is designed for the establishment of experimental venous intimal hyperplasia by interposing rabbit jugular veins to the ipsilateral carotid arteries. The protocol does not require surgical procedures deep in the body trunk and the extent of the incision is limited, which is less invasive for the animals, allowing long-term observation after implantation. This simple procedure enables researchers to investigate strategies to attenuate the progression of intimal hyperplasia of the implanted vein grafts. Using this protocol, we reported the effects transduction of microRNA-145 (miR-145), which is known to control the phenotype of vascular smooth muscle cells (VSMCs) from the proliferative to the contractile state, into harvested vein grafts. We confirmed the attenuation of intimal hyperplasia of vein grafts by transducing miR-145 before implantation surgery through the phenotype change of the VSMCs. Here we report a less invasive experimental platform to investigate the strategies that can be used to attenuate intimal hyperplasia of vein grafts in revascularization surgeries.

Editors' note: Carotid plaques and detection of atrial fibrillation in embolic stroke of undetermined source

In “Carotid plaques and detection of atrial fibrillation in embolic stroke of undetermined source,” Ntaios et al. studied 777 patients with embolic stroke of undetermined source (ESUS) and found that the presence of ipsilateral nonstenotic carotid plaque was associated with a significantly lower likelihood for atrial fibrillation. Siegler et al. questioned the modality used to identify nonstenotic carotid plaque and paroxysmal atrial fibrillation, given that this affects incidence rates. Furthermore, they noted that although the authors commented on the frequency of conditions during which atrial fibrillation was detected (such as routine ECG, stroke recurrence, and myocardial infarction), it would have been useful to compare the incidence rates for patients with and without plaque. Ntaios responded that unfortunately, they did not have access to information about the technique used to diagnose carotid plaque or atrial fibrillation and that they did not think it was appropriate to compare the incidence of conditions during which atrial fibrillation was detected without this information. Lattanzi et al. commented that it would be useful to assess the relationship between plaques and atrial fibrillation and other variables, such as atrial cardiopathy, which has been shown to be inversely related to artery-to-artery strokes. Ntaios responded that they have performed additional analysis and hope to have their results published soon. It is clear that further research into workup and management of ESUS is needed. In “Carotid plaques and detection of atrial fibrillation in embolic stroke of undetermined source,” Ntaios et al. studied 777 patients with embolic stroke of undetermined source (ESUS) and found that the presence of ipsilateral nonstenotic carotid plaque was associated with a significantly lower likelihood for atrial fibrillation. Siegler et al. questioned the modality used to identify nonstenotic carotid plaque and paroxysmal atrial fibrillation, given that this affects incidence rates. Furthermore, they noted that although the authors commented on the frequency of conditions during which atrial fibrillation was detected (such as routine ECG, stroke recurrence, and myocardial infarction), it would have been useful to compare the incidence rates for patients with and without plaque. Ntaios responded that unfortunately, they did not have access to information about the technique used to diagnose carotid plaque or atrial fibrillation and that they did not think it was appropriate to compare the incidence of conditions during which atrial fibrillation was detected without this information. Lattanzi et al. commented that it would be useful to assess the relationship between plaques and atrial fibrillation and other variables, such as atrial cardiopathy, which has been shown to be inversely related to artery-to-artery strokes. Ntaios responded that they have performed additional analysis and hope to have their results published soon. It is clear that further research into workup and management of ESUS is needed.

Reader response: Carotid plaques and detection of atrial fibrillation in embolic stroke of undetermined source.

We read with great interest the article by Ntaios et al.,1 which demonstrated a lower cumulative probability of atrial fibrillation (AF) detection in patients with embolic strokes of undetermined source (ESUS) with ipsilateral nonstenotic carotid plaques compared with those without.

External carotid artery stenting in symptomatic internal carotid artery occlusion

We report the case of a patient with an anterior ischemic stroke due to tandem occlusion of the left M2 segment and ipsilateral internal carotid artery (ICA), with concomitant severe stenosis of the ipsilateral external carotid artery (ECA) and contralateral ICA, and moderate stenosis of the left vertebral artery (VA); as thrombectomy was not possible, stenting of the right ICA was performed. Two days after significant recovery, the patient showed neurological deterioration when in upright position, and brain magnetic resonance imaging confirmed decreased cerebral blood flow on the left hemisphere. Stenting of the left ECA and balloon angioplasty of the ipsilateral VA were performed in order to increase collateral flow, with an almost complete resolution of symptoms. This case highlights the importance of assessing the collateralization pattern when an ICA occlusion is present, and the potential need to revascularize an ipsilateral stenotic ECA.

Vasoreactivity of the Murine External Jugular Vein and Carotid Artery

Few studies have characterized vasoreactivity of the murine external jugular vein. This segment often is used in preclinical models to evaluate vascular remodeling in response to arteriovenous fistula (AVF) maturation. When an AVF is established, the venous segment is exposed to arterial pressures and disturbed flow patterns that have strong potential to impact vasoreactivity. Before testing this hypothesis in the context of AVF, we sought to establish procedures to comprehensively characterize endothelium‐dependent and vascular smooth muscle function of the carotid artery and external jugular vein from healthy mice. External jugular veins and ipsilateral common carotid arteries were isolated from five‐month‐old male C57BL/6 mice and vasomotor responses were evaluated using isometric tension procedures. External jugular veins developed tension (p&lt;0.05) to the voltage‐gated Ca2+ channel opener potassium chloride (KCl) and the thromboxane A2 receptor agonist U‐46619, but not to the α‐1 receptor agonist phenylephrine (PE), whereas common carotid arteries responded to all three vasocontractile agents in a more robust (p&lt;0.05) manner. While maximal responses (~70%) to the endothelium‐dependent vasodilator acetylcholine (ACh) were similar between the venous and arterial segments, the dose required to achieve this value was lower (p&lt;0.05) in the artery versus the vein. Nitric oxide synthase (NOS) inhibition using L‐NMMA attenuated (p&lt;0.05) but did not abolish ACh‐evoked vasorelaxation in both vascular segments. Endothelium‐independent vasorelaxation to sodium nitroprusside (SNP) was similar in the artery and the vein. Endothelium‐dependent and vascular smooth muscle function can be reliably assessed in the murine external jugular vein of healthy male C57Bl/6 mice. Compared to common carotid arteries, external jugular veins are resistant to PE‐evoked vasocontraction, less responsive to KCl and U‐46619‐evoked vasocontraction, less sensitive to ACh‐evoked vasorelaxation, and equally responsive to NOS inhibition and guanylate cyclase activation via SNP. Ongoing studies will determine if and how external jugular vein function is altered by arterial pressures and disturbed flow patterns that are encountered subsequent to establishing an AVF.Support or Funding InformationJMC (University of Utah Graduate Research Fellowship); YTS (R01DK100505; I01BX004133); JDS (AHA16GRNT31050004, NIH RO3AGO52848, RO1HL141540); TL (R44DK109789, R01HL139692, I01BX003387).