Correlation of Computed Tomography Angiography to Digital Subtraction Angiography in Carotid Stenosis with Real-World Assessment of Overestimation of Carotid Stenosis on Computed Tomography Angiography.

OBJECTIVE: Computed tomography angiography (CTA) is a well-established diagnostic modality for carotid stenosis. However, false-positive CTA results may expose patients to unnecessary procedural complications in cases where surgical intervention is not warranted. We aim to assess the correlation of CTA to digital subtraction angiography (DSA) in carotid stenosis and characterize patients who were referred for intervention based on CTA and did not require it based on DSA. METHODS: We retrospectively reviewed 186 patients who underwent carotid angioplasty and stenting following preprocedural CTA at our institution from April 2017 to December 2022. RESULTS: Twenty-one of 186 patients (11.2%) were found to have <50% carotid stenosis on DSA (discordant group). Severe plaque calcification on CTA was associated with a discordant degree of stenosis on DSA (LR+=7.4). Among 186 patients, agreement between the percentage of stenosis from CTA and DSA was weak-moderate (r2=0.27, P<0.01). Among concordant pairs, we found moderate-strong agreement between CTA and DSA (adj r2=0.37) (P < 0.0001). Of 186 patients, 127 patients had CTA stenosis of ≥70%, and 59 had CTA of 50%-69%. Correlation between CTA and DSA in severe CTA stenosis was weak (r2=0.11, P<0.01). CONCLUSIONS: In patients with stenosis found on CTA, over 88% also had stenosis on DSA, with this positive predictive value in line with previous studies. The percent-stenosis value from CTA and DSA was weakly correlated but does not affect the overall clinical judgement of stenosis. Severe calcification found on CTA may potentially indicate nonstenosis on DSA.

Assessment of Plaque Characteristics by Contrast-Enhanced Ultrasound and Stent Restenosis following Carotid Artery Stenting: A Retrospective Study.

Background and objective: carotid artery stenosis contributes significantly to ischemic strokes, with management options including carotid endarterectomy (CEA) and carotid artery stenting (CAS) ischemic stroke risk can be reduced. Controversies persist regarding their efficacy and factors influencing complications, and understanding the relationship between atherosclerotic plaque characteristics and stent restenosis after CAS is crucial. Methods: we conducted a retrospective study involving 221 patients who underwent CAS for symptomatic or asymptomatic carotid artery stenosis. Comprehensive assessments of plaque morphology were performed using contrast-enhanced ultrasound (CEUS) before CAS. Patient demographics, including smoking status and diabetes, were also recorded. Stent restenosis was diagnosed using various imaging modalities, including ultrasound, angiography, and digital subtraction angiography (DSA). Results: plaque analysis using CEUS revealed a significant association between plaque grade and restenosis incidence (p < 0.001), particularly with grade 0 (11.1%) and grade 2 plaques (66.7%). Smoking was notably associated with plaque vascularization and restenosis (p < 0.001), while diabetes did not significantly impact plaque characteristics or restenosis risk (p > 0.05). The mean duration of restenosis was 17.67 months. Stenting was the most frequent treatment modality for restenosis (70.6%). However, no significant relationship was found between restenosis type and plaque morphology (p = 0.268). Furthermore, while no clear relationship was observed between plaque morphology and the type of restenosis, our findings underscored the importance of plaque characterization in predicting post-CAS outcomes. Conclusions: this study highlights the utility of CEUS in predicting stent restenosis following CAS. There was a significant association between stent restenosis within 12-24 months after the carotid stenting procedure and an elevated grade of plaque vascularization. Moreover, one of the main factors possibly determining the grade of plaque vascularization was smoking. Further research is warranted to elucidate the underlying mechanisms and refine risk stratification in this patient population.

Quantitative assessment of retinochoroidal microvasculature in patients with carotid artery stenosis using OCT angiography.

PURPOSE: To investigate the alterations in retinochoroidal parameters measured by optical coherence tomography (OCT) and OCT angiography (OCTA) in patients with carotid artery stenosis (CAS) and assess their associations with digital subtraction angiography (DSA) data. METHOD: This study enrolled patients diagnosed with CAS and age-matched healthy controls. Both groups underwent OCT and OCTA examinations. DSA and assessment of carotid artery stenosis were performed only in the CAS group. The study evaluated various retinochoroidal parameters from OCT and OCTA, including linear vessel density (LVD), foveal avascular zone (FAZ), choroidal thickness (ChT), and retinal nerve fiber layer (RNFL) thickness. DSA-derived measures included cervical segment (C1) diameter, cavernous segment (C4) diameter, stenosis percentage, ophthalmic artery (OA) filling time, C1-OA filling time, and residual stenosis. RESULTS: A total of 42 eyes from 30 CAS patients and 60 eyes from 30 healthy controls were included. Patients with CAS displayed significantly decreased LVD compared to controls (p < 0.001). Additionally, the CAS group had thinner choroid and RNFL (p = 0.047 and p < 0.001, respectively). Macular LVD negatively correlated with both stenosis percentage and C1-OA filling time (p = 0.010 and p = 0.014, respectively). In patients who underwent carotid artery stenting, preoperative ChT significantly correlated with residual stenosis (Pearson r = -0.480, p = 0.020). CONCLUSION: OCT and OCTA provide a quantitative assessment of retinochoroidal microstructural changes associated with CAS, suggesting potential for noninvasive evaluation of the disease. This might contribute to the prevention of irreversible ocular complications and early detection of CAS. Furthermore, ChT may not only aid in diagnosing CAS more reliably but also offer prognostic information.

Assessment of Collateral Flow in Patients with Carotid Stenosis Using Random Vessel-Encoded Arterial Spin-Labeling: Comparison with Digital Subtraction Angiography.

BACKGROUND AND PURPOSE: Collateral circulation plays an important role in steno-occlusive internal carotid artery disease (ICAD) to reduce the risk of stroke. We aimed to investigate the utility of planning-free random vessel-encoded arterial spin-labeling (rVE-ASL) in assessing collateral flows in patients with ICAD. MATERIALS AND METHODS: Forty patients with ICAD were prospectively recruited. The presence and extent of collateral flow were assessed and compared between rVE-ASL and DSA by using Contingency (C) and Cramer V (V) coefficients. The differences in flow territory alterations stratified by stenosis ratio and symptoms, respectively, were compared between symptomatic (n = 19) and asymptomatic (n = 21) patients by using the Fisher exact test. RESULTS: Good agreement was observed between rVE-ASL and DSA in assessing collateral flow (C = 0.762, V = 0.833, both P < .001). Patients with ICA stenosis of ≥90% were more likely to have flow alterations (P < .001). Symptomatic patients showed a higher prevalence of flow alterations in the territory of the MCA on the same side of ICAD (63.2%), compared with asymptomatic patients (23.8%, P = .012), while the flow alterations in the territory of anterior cerebral artery did not differ (P = .442). The collateral flow to MCA territory was developed primarily from the contralateral internal carotid artery (70.6%) and vertebrobasilar artery to a lesser extent (47.1%). CONCLUSIONS: rVE-ASL provides comparable information with DSA on the assessment of collateral flow. The flow alterations in the MCA territory may be attributed to symptomatic ICAD.

3-D Contrast-Enhanced Fusion Ultrasound for Accurate Volume Assessment of Vessel Lumen and Plaque in Carotid Artery Disease as Compared With Computed Tomography Angiography.

OBJECTIVE: Three-dimensional contrast-enhanced fusion ultrasound (CEFUS) of atherosclerotic carotid arteries provides spatial visualization of the vessel lumen, creating a lumenography. As in 3-D computed tomography angiography (CTA), 3-D CEFUS outlines the contrast-filled lumen. Plaque and vessel contours are distinguished in 3-D CEFUS, allowing plaque volume quantification as a valid estimate of carotid plaque burden. Three-dimensional CEFUS is unproven in intermodality studies, vindicating the assessment of 3-D CEFUS applicability and comparing 3-D CEFUS and 3-D CTA lumenography as a proof-of-concept study. METHODS: Using an ultrasound system with magnetic tracking, a linear array transducer and SonoVue contrast agent, 3-D CEFUS acquisitions were generated by spatial stitching of serial 2-D images. From 3-D CEFUS and 3-D CTA imaging, the atherosclerotic carotid arteries were reconstructed with lumenography in an offline software program for lumen and plaque volume quantification. Bland-Altman analysis was used for inter-image modality agreement. RESULTS: The study included 39 carotid arteries. Mean lumen and plaque volume in 3-D CEFUS were 0.63 cm3 (standard deviation [SD]: 0.26) and 0.62 cm3 (SD: 0.26), respectively. Lumen volume differences between 3-D CEFUS and 3-D CTA were non-significant, with a mean difference of 0.01 cm3 (SD: 0.02, p = 0.26) and limits of agreement (LoA) range of ±0.11 cm3. Mean plaque volume difference was -0.12 cm3 (SD: 0.19, p = 0.006) with a LoA range of ±0.39 cm3. CONCLUSION: There was strong agreement in lumenography between 3-D CEFUS and 3-D CTA. The interimage modality difference in plaque volumes was substantial because of challenging vessel wall definition in 3-D CTA. Three-dimensional CEFUS is viable in quantifying carotid plaque volume burden and can potentially monitor plaque development over time.

Rapid Carotid Screening by Duplex: A Prospective Single Centre Assessment.

OBJECTIVE: A novel carotid quick scan (CQS) protocol was developed to rapidly screen for carotid atherosclerosis greater than 50% stenosis in a vascular outpatient setting. This study assessed accuracy and time saved. MATERIAL & METHODS: The CQS was developed by consensus agreement between vascular surgeons and accredited clinical vascular scientists through a modified Delphi technique. The protocol comprised a rapid B-mode then colour flow transverse sweep of the common and internal carotid arteries, with internal carotid artery velocity assessment. One hundred outpatients attending with peripheral artery disease or abdominal aortic aneurysm were recruited. CQS sensitivity, specificity and accuracy was assessed against a conventional full carotid duplex study, performed to UK and ESVS guidelines. RESULTS: Twenty four percent of patients (n = 100) had >50% carotid NASCET stenosis. CQS achieved an excellent accuracy of 96.5% in detecting >50% stenosis when compared to full duplex; Cohen's ƙ = .88, (95%CI .79-.97; P < .001), sensitivity 91.4%, specificity 97.6%, positive predictive value (PPV) 88.9% and negative predictive value (NPV) 98.2%. Median (IQR) time to complete the CQS was 13 sec (±12) per side, compared to 151 sec (±78) per side for the full carotid duplex. In the presence of >50% carotid disease, median CQS time was 25 sec (±31) per side compared to 214 (±104) by full scan. CONCLUSION: CQS as a carotid screening tool is rapid, accurate and acceptable to the population and workforce. It would be simple to roll out in all vascular laboratories to reduce the time and cost burden of excluding significant carotid disease in any group.

Carotid Endarterectomy Should Not Be Recommended to End-Stage Kidney Disease Patients with Asymptomatic Carotid Artery Disease.

BACKGROUND: Carotid endarterectomy (CEA) for asymptomatic carotid artery disease is advised for patients with low perioperative stroke risk and life expectancy of 3-5 years. We sought to explore the role of risk stratification and postoperative medical management in identifying appropriate asymptomatic candidates for CEA in the end-stage kidney disease (ESKD) population. METHODS: We identified ESKD patients on dialysis from the United States Renal Data System that underwent CEA (2008-2014) for asymptomatic carotid artery disease. We used the Liu comorbidity index as well as a novel risk prediction model based on Cox proportional hazards model to stratify patients. The primary outcome evaluated was 3-year survival, and Kaplan-Meier methods were used to generate survival estimates. We further conducted a subanalysis of patients with Medicare part D data to determine postoperative usage of the following medications: statins, antiplatelets, and antihypertensives. We evaluated the association of medication utilization and 3-year survival using Kaplan-Meier methods and Cox proportional hazards modeling. RESULTS: We analyzed 1,813 patients meeting inclusion criteria. The population was predominantly older (mean age 70.2 ± 9.1), White (84.8%), and had a high prevalence of cardiovascular comorbidities, such as hypertension (90.7%), diabetes (62.5%), and congestive heart failure (35.4%). Among the entire cohort, 23.0% had a Liu comorbidity index ≤8, 35.0% had index 9-12, and 42.0% had index >12. Increasing Liu comorbidity index was associated with worse survival (P < 0.01); however, even the group with Liu index ≤8 had poor 3-year survival of 58.8% (53.9-63.4). The Cox proportional hazards model identified variables for inclusion in the risk model such as age >80 (adjusted hazard ratio [aHR] = 2.49, 95% confidence interval [CI] [1.87-3.33], P < 0.001), congestive heart failure (aHR = 1.31, 95% CI [1.14-1.51], P < 0.001), and Liu comorbidity index >12(aHR = 1.89, 95% CI [1.56-2.28], P < 0.001). The risk score generated ranged from 0 to 6.5, and patients were divided into 3 groups: score ≤2 (43.4%), 2-4 (41.2%), and >4 (15.4%). Increasing risk score was associated with worse survival (P < 0.01) but even the "low-risk" group had 3-year survival of 58.5% (54.9-61.9). Subanalysis of the 1,249 (68.8% of total) patients with part D data found that statins and calcium channel blocker use was associated with improved survival, although observed rates for patients on drug were still low. CONCLUSIONS: The overall long-term survival of ESKD patients undergoing CEA for asymptomatic carotid artery disease is low. Risk stratification and analysis of postoperative medical management did not identify a subgroup of patients with adequate 3-year survival. Hence, the preventive benefits of CEA are not realized in these patients.

Long-term outcomes of carotid endarterectomy vs transfemoral carotid stenting in a Medicare-matched database.

BACKGROUND: Carotid endarterectomy (CEA) is associated with lower risk of perioperative stroke compared with transfemoral carotid artery stenting (TFCAS) in the treatment of carotid artery stenosis. However, there is discrepancy in data regarding long-term outcomes. We aimed to compare long-term outcomes of CEA vs TFCAS using the Medicare-matched Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database. METHODS: We assessed patients undergoing first-time CEA or TFCAS in Vascular Quality Initiative Vascular-Vascular Implant Surveillance and Interventional Outcomes Network from January 2003 to December 2018. Patients with prior history of carotid revascularization, nontransfemoral stenting, stenting performed without distal embolic protection, multiple or nonatherosclerotic lesions, or concomitant procedures were excluded. The primary outcome of interest was all-cause mortality, any stroke, and a combined end point of death or stroke. We additionally performed propensity score matching and stratification based on symptomatic status. RESULTS: A total of 80,146 carotid revascularizations were performed, of which 72,615 were CEA and 7531 were TFCAS. CEA was associated with significantly lower risk of death (57.8% vs 70.4%, adjusted hazard ratio [aHR], 0.46; 95% confidence interval [CI], 0.41-0.52; P < .001), stroke (21.3% vs 26.6%; aHR, 0.63; 95% CI, 0.57-0.69; P < .001) and combined end point of death and stroke (65.3% vs 76.5%; HR, 0.49; 95% CI, 0.44-0.55; P < .001) at 10 years. These findings were reflected in the propensity-matched cohort (combined end point: 34.6% vs 46.8%; HR, 0.53; 95% CI, 0.46-0.62) at 4 years, as well as stratified analyses of combined end point by symptomatic status (asymptomatic: 63.2% vs 74.9%; HR, 0.49; 95% CI, 0.43-0.58; P < .001; symptomatic: 69.9% vs 78.3%; HR, 0.51; 95% CI, 0.45-0.59; P < .001) at 10 years. CONCLUSIONS: In this analysis of North American real-world data, CEA was associated with greater long-term survival and fewer strokes compared with TFCAS. These findings support the continued use of CEA as the first-line revascularization procedure.

Decision aids for patients with carotid stenosis.

BACKGROUND: Shared decision-making tools have been underused by clinicians in real-world practice. Changes to the National Coverage Determination by Medicare for carotid stenting greatly expand the coverage for patients, but simultaneously require a shared decision-making interaction that involves the use of a validated tool. Accordingly, our objective was to evaluate the currently available decision aids for carotid stenosis. METHODS: We conducted a review of the literature for published work on decision aids for the treatment of carotid disease. RESULTS: Four publications met inclusion criteria. We found the format of the decision aid impacted patient comprehension and decision making, although patient characteristics also played a role in the therapeutic decisions made. Notably, none of the available decision aids included the widely adopted transcarotid artery revascularization as an option. CONCLUSIONS: Further work is needed in the development of a widespread validated decision aid instrument for patients with carotid stenosis.

Ultrasound assessment of brain supplying arteries (extracranial). / Die Ultraschalluntersuchung der hirnversorgenden Arterien (extrakraniell).

Ultrasonography of the brain-supplying arteries is a non-invasive and highly efficient technique for the assessment of a stenosis or a vessel occlusion in patients with cerebrovascular diseases. This article reviews the examination technique for a standardized ultrasound assessment of the extracranial carotid and vertebral arteries. It further describes the multiparametric grading criteria of internal carotid artery stenosis and it gives recommendations for a standardised documentation of findings. Additionally, it proposes recommendations for intima-media thickness measurement and for classifying atherosclerotic plaques with B-mode ultrasonography. Moreover, criteria for the diagnosis of in-stent stenoses, vertebral artery dissections and subclavian steal syndrome are provided.

Carotid Artery Stenting versus Carotid Endarterectomy in Terms of Neuroprotection DW-MRI Detected and Neuropsychological Assessment Impairment.

BACKGROUND: Carotid artery stenting (CAS) versus carotid endarterectomy (CEA) is well issue known, but the purpose of this study is to compare CAS versus CEA in terms of asymptomatic Diffusion-weighted magnetic resonance imaging (DW-MRI) demonstrated microembolic scattering of infarction and neuropsychological assessment impairment. METHODS: We performed a prospective, observational, cohort study on 211 consecutive carotid revascularizations at our institution. Patients were divided into 2 different cohorts: CEA was performed in n = 116 patients (Group A); CAS was performed in n = 95 (Group B). Adverse events were collected at 30 days and 6 months postoperative. Differences in terms of DW-MRI demonstrated microembolic scattering of infarction were analyzed and considered significative for P ≤ 0.05. Secondary objectives were: major and minor stroke, neuropsychological assessment impairment, death, myocardial infarction (MI). RESULTS: CEA was associated with a significative decreased rate of asymptomatic DW-MRI demonstrated microembolic scattering of infarction (13.8% vs. 51%; P = 0.0001) and of 6 months neuropsychological assessments impairment (0.8 vs. 7.4) (P = 0.04) in asymptomatic patients. There was no significant difference between 2 groups in terms of comorbidities. Stroke rates were similar at 30 days (1.7% CEA vs. 4.1% CAS) and 6 months (2.6% CEA vs. 5.3% CAS P = 0.32). There were no differences in terms of central neurological events, death, transient ischemic attack, MI between the groups. The composite end point of stroke/death/MI at 6 months postoperatively was 2.6% vs. 6.3% (P = 0.19). CONCLUSIONS: According to these results, CEA achieved better outcomes compared to patients treated by CAS with distal filter in terms of asymptomatic microembolic event and impairment National Institutes of Health Stroke Scale scale and neuropsychological assessments. Limitations of the study lead to limited conclusions only in the specific population and not generalized. Further, comparative randomized studies are warranted.

HViT: Hybrid vision inspired transformer for the assessment of carotid artery plaque by addressing the cross-modality domain adaptation problem in MRI.

BACKGROUND: Medical image classification is crucial for accurate and efficient diagnosis, and deep learning frameworks have shown significant potential in this area. When a general learning deep model is directly deployed to a new dataset with heterogeneous features, the effect of domain shifts is usually ignored, which degrades the performance of deep learning models and leads to inaccurate predictions. PURPOSE: This study aims to propose a framework that utilized the cross-modality domain adaptation and accurately diagnose and classify MRI scans and domain knowledge into stable and vulnerable plaque categories by a modified Vision Transformer (ViT) model for the classification of MRI scans and transformer model for domain knowledge classification. METHODS: This study proposes a Hybrid Vision Inspired Transformer (HViT) framework that employs a convolutional layer for image pre-processing and normalization and a 3D convolutional layer to enable ViT to classify 3D images. Our proposed HViT framework introduces a slim design with a multi-branch network and channel attention, improving patch embedding extraction and information learning. Auxiliary losses target shallow features, linking them with deeper ones, enhancing information gain, and model generalization. Furthermore, replacing the MLP Head with RNN enables better backpropagation for improved performance. Moreover, we utilized a modified transformer model with LSTM positional encoding and Golve word vector to classify domain knowledge. By using ensemble learning techniques, specifically stacking ensemble learning with hard and soft prediction, we combine the predictive power of both models to address the cross-modality domain adaptation problem and improve overall performance. RESULTS: The proposed framework achieved an accuracy of 94.32% for carotid artery plaque classification into stable and vulnerable plaque by addressing the cross-modality domain adaptation problem and improving overall performance. CONCLUSION: The model was further evaluated using an independent dataset acquired from different hardware protocols. The results demonstrate that the proposed deep learning model significantly improves the generalization ability across different MRI scans acquired from different hardware protocols without requiring additional calibration data.

Assessment of cerebral autoregulatory function and inter-hemispheric blood flow in older adults with internal carotid artery stenosis using transcranial Doppler sonography-based measurement of transient hyperemic response after carotid artery compression.

Unhealthy vascular aging promotes atherogenesis, which may lead to significant internal carotid artery stenosis (CAS) in 5 to 7.5% of older adults. The pathogenic factors that promote accelerated vascular aging and CAS also affect the downstream portion of the cerebral microcirculation in these patients. Primary treatments of significant CAS are eversion endarterectomy or endarterectomy with patch plasty. Factors that determine adequate hemodynamic compensation and thereby the clinical consequences of CAS as well as medical and surgical complications of carotid reconstruction surgery likely involve the anatomy of the circle of Willis (CoW), the magnitude of compensatory inter-hemispheric blood flow, and the effectiveness of cerebral microcirculatory blood flow autoregulation. This study aimed to test two hypotheses based on this theory. First, we hypothesized that patients with symptomatic and asymptomatic CAS would exhibit differences in autoregulatory function and inter-hemispheric blood flow. Second, we predicted that anatomically compromised CoW would associate with impaired inter-hemispheric blood flow compensation. We enrolled older adults with symptomatic or asymptomatic internal CAS (>70% NASCET criteria; n = 46) and assessed CoW integrity by CT angiography. We evaluated transient hyperemic responses in the middle cerebral arteries (MCA) after common carotid artery compression (CCC; 10 s) by transcranial Doppler sonography (TCD). We compared parameters reflecting autoregulatory function (e.g., transient hyperemic response ratio [THRR], return to baseline time [RTB], changes of vascular resistance) and inter-hemispheric blood flow (residual blood flow velocity). Our findings revealed that CAS was associated with impaired cerebral vascular reactivity. However, we did not observe significant differences in autoregulatory function or inter-hemispheric blood flow between patients with symptomatic and asymptomatic CAS. Moreover, anatomically compromised CoW did not significantly affect these parameters. Notably, we observed an inverse correlation between RTB and THRR, and 49% of CAS patients exhibited a delayed THRR, which associated with decreased inter-hemispheric blood flow. Future studies should investigate how TCD-based evaluation of autoregulatory function and inter-hemispheric blood flow can be used to optimize surgical techniques and patient selection for internal carotid artery revascularization.

Comparison of Complications and Cost for Transfemoral Versus Transcarotid Stenting of Carotid Artery Stenosis.

BACKGROUND: Options for endovascular treatment of carotid artery disease have been developed to compliment with carotid endarterectomy, transfemoral carotid artery stenting (TFCAS) and a hybrid approach with transcarotid artery revascularization (TCAR). We sought to capture endpoints outside of stroke, myocardial infarction (MI), and death involved with each procedure at our institution as well as evaluate cost. METHODS: Carotid stent procedures performed from 2014 to 2020 at our institution underwent comparative analysis based upon access site and type of stent procedure performed, TFCAS versus TCAR. Procedural details and outcomes were captured prospectively and included in the National Cardiovascular Data Peripheral Vascular Intervention Registry (NCDR-PVI). Further retrospective review was performed to evaluate endpoints beyond stroke, MI, and death. Total in-hospital cost, including administrative, capital and utilities (fixed cost), and labor and supplies (variable cost) were also evaluated. RESULTS: One hundred thirty-seven patients were reviewed. Seventy-seven were treated with TFCAS and 60 with TCAR. The mean age was 74 years, predominantly male (68%) and Caucasian (90%). Patients undergoing TFCAS were more likely to be symptomatic compared to those receiving TCAR (81.8% vs. 50.0%, P = <0.001). There were no statistically significant differences in event rates, including mortality, recurrent cerebrovascular accident / transient ischemic attack, or bleeding. Complications not captured in the NCDR-PVI database were more frequent in the TCAR group (21.7% vs. 5.2%, P = 0.004) and included pneumothorax (n = 2), neck hematoma (n = 8), and common carotid artery stenosis or injury (n = 3). Rates of complications in the TFCAS group (n = 4) were lower and limited to groin hematoma (n = 2), central retinal artery occlusion causing vision loss and a case of postoperative dysphagia. Geographic miss of initial stent placement was identified in 15.0% of TCAR patients and 2.6% (P = 0.008) of TFCAS patients. Restenosis rates on duplex ultrasound were similar between the two groups (14.6% of patients) and were not associated with symptoms. The mean follow-up interval was similar for both groups of 31.8 months for TCAR and 30.7 months for TFCAS (P = 0.797). There was a statistically significant difference in total cost with TCAR being more expensive ($22,315 vs. $11,001) driven by direct costs that included devices, imaging, and extended length of stay in the TCAR group (P < 0.001). There was no significant difference between stroke free survival (91.1% vs. 88.6%, P = 0.69) and mortality (78.1% vs. 85.2%, P = 0.677) at 3 years follow-up between TCAR and TFCAS, respectively. CONCLUSIONS: Both TFCAS and TCAR provide similar 3-year stroke and mortality risk/benefit and are distinctly different procedures. Both should be evaluated independently with analysis of variables beyond stroke, death, and MI. TFCAS is more cost-effective than TCAR in this single institution study.

Assessment of extracranial carotid artery disease using digital twins - A pilot study.

To improve risk stratification in extracranial internal carotid artery disease (CAD), patients who would benefit maximally from revascularization must be identified. In cardiology, the fractional flow reserve (FFR) has become a reference standard for evaluating the functional severity of coronary artery stenosis, and noninvasive surrogates thereof relying on computational fluid dynamics (CFD) have been developed. Here, we present a CFD-based workflow using digital twins of patients' carotid bifurcations derived from computed tomography angiography for the noninvasive functional assessment of CAD. We reconstructed patient-specific digital twins of 37 carotid bifurcations. We implemented a CFD model using common carotid artery peak systolic velocity (PSV) acquired with Doppler ultrasound (DUS) as inlet boundary condition and a two-element Windkessel model as oulet boundary condition. The agreement between CFD and DUS on the PSV in the internal carotid artery (ICA) was then compared. The relative error for the agreement between DUS and CFD was 9% ± 20% and the intraclass correlation coefficient was 0.88. Furthermore, hyperemic simulations in a physiological range were feasible and unmasked markedly different pressure drops along two ICA stenoses with similar degree of narrowing under comparable ICA blood flow. Hereby, we lay the foundation for prospective studies on noninvasive CFD-based derivation of metrics similar to the FFR for the assessment of CAD.

Society for Vascular Surgery duplex ultrasound surveillance guidelines are safe and cost effective for transcarotid artery revascularization.

BACKGROUND: Carotid duplex ultrasound (CDUS) examination is used in the long-term surveillance after transcarotid artery revascularization (TCAR). The objective of this study was to evaluate the usefulness and cost effectiveness of post-TCAR CDUS surveillance regimens in monitoring for in-stent restenosis (ISR) and associated stroke risk at a single-center community institution. METHODS: CDUS data were collected retrospectively from patients who had undergone TCAR between January 2017 and January 2023. ISR >50% was defined as a peak systolic velocity (PSV) of >220 cm/s and an internal carotid artery (ICA) to common carotid velocity ratio of >2.7. ISR >80% was defined as a PSV of >340 cm/s and an ICA/common carotid artery ratio of >4.15. Study outcomes included incidences of ISR, reintervention, transient ischemic attacks (TIAs), strokes, and mortality. A Kaplan-Meier survival analysis was done to calculate the rates of freedom from ISR. RESULTS: During the study period, 108 TCAR stents were deployed in 104 patients. Eight patients were excluded in analysis or lost to follow-up. Preoperatively, 62% of patients had >80% stenosis, and 39% were symptomatic. No intraprocedural complications were noted. One patient suffered an immediate postoperative dissection. Eight stents (8%) experienced ISR progression from <50% to >50%. Three of the eight had further ISR progression to >80%. One patient had high-grade ISR and a contralateral ICA occlusion that warranted reintervention. There were no occurrences of postoperative TIAs, strokes, or TCAR-related deaths. Rates of freedom from ISR progression from <50% to >50% were 97.4%, 95.9%, 90.9%, 88.2%, and 88.2% at 6, 12, 24, 36, and 42 months, respectively. Rates of freedom from ISR >80% were 100%, 100%, 98.5%, 95.5%, and 95.5% at the same time points. Patients with >50% ISR tended to be females with hyperlipidemia. In addition, they had higher average lesion lengths and lower rates of postdilation balloon angioplasty. The 5-year estimated surveillance cost in this cohort using the Society for Vascular Surgery 2022, and 2018 guidelines, as well as our current protocol would be $113,853, $221,382, and $193,207, respectively. CONCLUSIONS: This study revealed a low incidence of ISR progression, as well as no TIA, stroke, or TCAR-related deaths, highlighting the safety and efficacy of TCAR. Post-TCAR CDUS examination using the updated Society for Vascular Surgery guidelines are safe and cost effective. Patients with contralateral occlusion or stenosis, or who have significant risk factors, should have more frequent surveillance regimens.

Contrast-Enhanced Ultrasound Combined With 2D Strain Imaging and Histopathological Multimodal Assessment of Carotid Plaque Vulnerability.

OBJECTIVE: The aim of this study was to explore the value of contrast-enhanced ultrasound (CEUS) combined with 2-D strain imaging in evaluating carotid plaque vulnerability and the correlations among CEUS perfusion parameters, strain parameters and histopathological findings in different plaque segments. METHODS: Patients with carotid artery stenosis who underwent carotid endarterectomy (CEA) at the First Affiliated Hospital of Xinjiang Medical University from September 2020 to June 2021 underwent preoperative carotid artery 2-D ultrasonography and CEUS. The plaques were divided into three segments: the proximal end of the shoulder, central cap and distal end of the shoulder. The peak intensity (PI) value and strain rate parameters of the regions of interest were analyzed. Plaques were divided into a stable group (8 cases) and an unstable group (19 cases). The microvascular density (MVD) and vascular endothelial growth factor (VEGF) expression of each patch in the unstable group were analyzed. RESULTS: The peak strain during the systolic period in each plaque segment in both groups showed the following pattern: proximal end shoulder > distal end shoulder > top (p < 0.05). The PI value for CEUS is also represented. In the unstable group, the PI values of each segment of the plaque were positively correlated with the MVD, near-center PI value and VEGF average optical density value. The average optical density of each segment was positively correlated with the MVD (p < 0.05). There were positive correlations between the PI values of the proximal and distal shoulder and the strain values (p < 0.05), and the MVD value of each segment, VEGF value and strain value were positively correlated (p < 0.05). CONCLUSION: PI and the pathological tissue components represented by CEUS were positively correlated with the mechanical parameters of the plaque along the long axis. There may be overlap between the high shear stress area of the plaque and the neovascular aggregation area, and the combination of the two has certain significance for assessing the vulnerability of the plaque.

Vascular Quality Initiative assessment of compliance with Society for Vascular Surgery clinical practice guidelines on the management of extracranial cerebrovascular disease.

OBJECTIVES: Compliance with Society for Vascular Surgery (SVS) clinical practice guidelines (CPGs) is associated with improved outcomes for the treatment of abdominal aortic aneurysm, but this has not been assessed for carotid artery disease. The Vascular Quality Initiative (VQI) registry was used to examine compliance with the SVS CPGs for the management of extracranial cerebrovascular disease and its impact on outcomes. METHODS: The 2021 SVS extracranial cerebrovascular disease CPGs were reviewed for evaluation by VQI data. Compliance rates by the center and provider were calculated, and the impact of compliance on outcomes was assessed using logistic regression with inverse probability-weighted risk adjustment for each CPG recommendation, allowing for clustering by the center. Our primary outcome was a composite end point of in-hospital stroke/death. As a secondary analysis, compliance with the 2021 SVS carotid implementation document recommendations and associated outcomes were also assessed. RESULTS: Of the 11 carotid CPG recommendations, 4 (36%) could be evaluated using VQI registry data. Median center-specific CPG compliance ranged from 38% to 95%, and median provider-specific compliance ranged from 36% to 100%. After adjustment, compliance with 2 of the recommendations was associated with lower rates of in-hospital stroke/death: first, the use of best medical therapy (antiplatelet and statin therapy) in low/standard surgical risk patients undergoing carotid endarterectomy for >70% asymptomatic stenosis (event rate in compliant vs noncompliant cases 0.59% vs 1.3%; adjusted odds ratio: 0.44, 95% confidence interval: 0.29-0.66); and second, carotid endarterectomy over transfemoral carotid artery stenting in low/standard surgical risk patients with >50% symptomatic stenosis (1.9% vs 3.4%; adjusted odds ratio: 0.55, 95% confidence interval: 0.43-0.71). Of the 132 implementation document recommendations, only 10 (7.6%) could be assessed using VQI data, with median center- and provider-specific compliance rates ranging from 67% to 100%. The impact of compliance on outcomes could only be assessed for 6 (4.5%) of these recommendations, and compliance with all 6 recommendations was associated with lower stroke/death. CONCLUSIONS: Few SVS recommendations could be assessed in the VQI because of incongruity between the recommendations and the VQI data variables collected. Although guideline compliance was extremely variable among VQI centers and providers, compliance with most of these recommendations was associated with improved outcomes after carotid revascularization. This finding confirms the value of guideline compliance, which should be encouraged for centers and providers. Optimization of VQI data to promote evaluation of guideline compliance and distribution of these findings to VQI centers and providers will help facilitate quality improvement efforts in the care of vascular patients.