Intravascular ultrasonography assisted carotid artery stenting for treatment of carotid stenosis: Two case reports

BACKGROUND Digital subtraction angiography(DSA),the gold standard of cerebrovascular disease diagnosis,is limited in its diagnostic ability to evaluate arterial diameter.Intravascular ultrasonography(IVUS)has advantages in assessing stenosis and plaque nature and improves the evaluation and effectiveness of carotid artery sten-ting(CAS).CASE SUMMARY Case 1:A 65-year-old man presented with a five-year history of bilateral lower limb weakness due to stroke.Physical examination showed decreased strength(5-/5)in both lower limbs.Carotid artery ultrasound,magnetic resonance angiography,and computed tomography angiography(CTA)showed a right proximal internal carotid artery(ICA)stenosis(70%-99%),acute cerebral infarction,and severe right ICA stenosis,respectively.We performed IVUS-assisted CAS to measure the stenosis and detected a low-risk plaque at the site of stenosis prior to stent implantation.Post-stent balloon dilatation was performed and postoperative IVUS demonstrated successful expansion and adherence.CTA six months postoperatively showed no significant increase in in-stent stenosis.Case 2:A 36-year-old man was admitted with a right common carotid artery(CCA)dissection detected by ultrasound.Physical examination showed no positive neurological signs.Carotid ultrasound and CTA showed lumen dilation in the proximal CCA with an intima-like structure and bulging in the proximal segment of the right CCA with strip-like low-density shadow(dissection or carotid web).IVUS-assisted DSA confirmed right CCA dissection.CAS was performed and intraoperative IVUS suggested a large residual false lumen.Post-stent balloon dilatation was performed reducing the false lumen.DSA three months postoperatively indicated good stent expansion with mild stenosis.CONCLUSION IVUS aids decision-making during CAS by accurately assessing carotid artery wall lesions and plaque nature preoperatively,dissection and stenosis morphology intraoperatively,and visualizing and confirming CAS postoperatively.

Comparison of the Values of MRI in the Differential Diagnosis of Symptomatic Carotid Stenosis and Atherosclerotic Plaque

Objective:To evaluate the values of Carotid Magnetic Resonance Imaging(MRI)in the differential diagnosis of symptomatic carotid stenosis and atherosclerotic plaque.Methods:56 patients with ischemic cerebrovascular disease admitted in our hospital from October 2018 to October 2019 were selected and treated with Carotid MRI and digital subtraction angiography(DSA)examinations.According to the two examination results recorded and the“gold standard”of DSA examination,values of Carotid MRI in the differential diagnosis of symptomatic carotid stenosis were evaluated.Results:According to the“gold standard”of DSA examination,the sensitivity and specificity of MRI examination for carotid stenosis were:Mild:92.54%and 97.78%;Moderate:85.71%and 88.78%;Severe:100.00%and 97.8%;and complete occlusion:100.00%and 100.00%;The proportions of intraplaque haemorrhage and ruptured fibrous cap in different degrees of carotid artery stenosis were:Mild:30.16%and 22.22%;Moderate:43.48%and 39.13%;And severe:57.89%and 52.63%.Conclusion:MRI examination can evaluate the degree of symptomatic carotid artery stenosis,and show the characteristics of atherosclerotic plaque at the same time to provide a reference for early clinical differential diagnosis and treatment.

A meta-analysis of carotid endarterectomy versus stenting in the treatment of symptomatic carotid stenosis

Background Carotid stenosis is one of the common reasons for patients with ischemic stroke, and the two invasive options carotid endarterectomy （CEA） and carotid artery stenting （CAS） are the most popular treatments. But the relative efficacy and safety of the methods are not clear. Methods About 521 articles related to CAS and CEA for carotid stenosis published in 1995-2011 were retrieved from MEDLINE, Cochrane Library （CL）, and China National Knowledge Infrastructure （CNKI） China Journal Full-Test database. Of them, eight articles were chosen. Meta-analysis was used to assess the relative risks. Results The eight studies included 3873 patients with symptomatic carotid artery stenosis, including 1941 cases in the carotid stent angioplasty group, and 1932 cases in the carotid endarterectomy group. Fixed effect model analysis showed that within 30 days of incidence of all types of strokes, surgery was significantly highly preferred in CAS patients （CAS group） than the CEA patients （CEA group）, and the difference was statistically significant （relative ratio （RR）=1.80, 95% confidence interval （CI）： 1.380-2.401, P 〈0.0001）. But the incidence of death in the two groups is not showed and is not statistically significant after 30 days （RR=1.52, 95% CI： 0.82-2.82, P=0.18）. The rate of cranial nerve injury in the CAS group is lower than the CEA group （RR=0.14, 95% CI： 0.05-0.43, P=0.0005）. The incidence of CAS patients with myocardial infarction is lower than the CEA group after 30 days, but statistically meaningless （RR=0.22, 95% CI： 0.05-1.02, P=0.05）. The stroke or death in CAS patients were higher than the CEA group after 1 year of treatment （RR=2.58, 95% CI： 1.03-6.48, P=0.04）. Conclusions Compared to CAS, carotid endarterectomy is still the preferred treatment methodology of symptomatic carotid artery stenosis. Future meta-analyses should then be performed in long-term follow-up to support this treatment recommendation.

Detection of Asymptomatic Carotid Artery Stenosis in High-Risk Individuals of Stroke Using a Machine-Learning Algorithm

Objective Asymptomatic carotid stenosis(ACS)is closely associated to the incidence of severe cerebrovascular diseases.Early identifying the individuals with ACS and its associated risk factors could be beneficial for primary prevention of stroke.This study aimed to investigate a machine-learning algorithm for the detection of ACS among high-risk population of stroke based on the associated risk factors.Methods A novel model of machine learning was utilized to screen the associated predictors of ACS based on 30 potential risk factors.The algorithm of this model adopted a random forest pattern based on the training data and then was verified using the testing data.All of the original data were retrieved from the China National Stroke Screening and Prevention Project(CNSSPP),including demographic,clinical and laboratory characteristics.The individuals with high risk of stroke were enrolled and randomly divided into a training group and a testing group at a ratio of 4:1.The identification of carotid stenosis by carotid artery duplex scans was set as the golden standard.The receiver operating characteristic(ROC)curve and the area under the curve(AUC)was used to evaluate the efficacy of the model in detecting ACS.Results Of 2841 high risk individual of stroke enrolled,326(11.6%)were diagnosed as ACS by ultrasonography.The top five risk fectors contributing to ACS in this model were identified as family history of dyslipidemia,high level of lowdensity lipoprotein cholesterol(LDL-c),low level of high-density lipoprotein cholesterol(HDL-c),aging,and low body.

Association between Fundus Atherosclerosis and Carotid Arterial Atherosclerosis

Objective: To investigate the correlation between fundus atherosclerosis and carotid arterial atherosclerosis. Methods: A total of 516 people undergoing physical examination in Deyang People’s Hospital between June 2020 and December 2022 were randomly selected. Fundus atherosclerosis and carotid arterial atherosclerosis were evaluated by fundus photography and carotid artery ultrasonography, respectively. Results: Among the 516 physical examination patients, 198 (38.4%) had normal fundus examination, and 318 (61.6%) had fundus arteriosclerosis. Among them, 166 cases were of grade I (32.2%), 86 cases were of grade II (16.7%), and 66 cases were of grade III (12.8%). There were 286 cases (55.4%) without carotid atherosclerosis, 201 cases (38.9%) with carotid atherosclerotic plaque, and 33 cases (6.4%) with carotid stenosis. Fundus arteriosclerosis is independently associated with carotid artery intima-media thickness, vulnerable plaques, plaque scores, and carotid artery stenosis (P Conclusion: In summary, there is a close relationship between carotid artery disease and the degree of arteriosclerosis in the eyeground. Fundus photography is a simple, non-invasive, and easily acceptable method of inspection. The results obtained from it are useful in determining the severity of carotid atherosclerosis and guiding early detection and intervention in clinical cases. This can help reduce the incidence of cardiovascular and cerebrovascular diseases.

An Integrated Analysis of Risk Factors of Cognitive Impairment in Patients with Severe Carotid Artery Stenosis

Objective To investigate cognitive dysfunction in patients with carotid artery stenosis(CAS) and potential risk factors related to cognitive-especially memory-dysfunction. Methods Forty-seven patients with carotid artery stenosis were recruited into our study cohort. The Mini-Mental State Examination(MMSE) and the Montreal Cognitive Assessment(MoCA) were adopted to assess cognitive function, the Wechsler Memory Scale(WMS) to assess memory function, high-resolution MRI and enhanced ultrasound to evaluate carotid plaques, and computed tomography perfusion(CTP) imaging to evaluate intracranial blood perfusion. Single-factor analysis and multiple-factor regression analysis were used to analyze potential risk factors of cognitive impairment. Results Mini-Mental State Examination test results showed that 22 patients had cognitive impairment, and MoCA test results showed that 10 patients had cognitive impairment. Analysis of various risk factors indicated that the average memory quotient of female patients was higher than that of males(P = 0.024). The cognitive and memory performance of those with an educational background above high school were significantly better than those of participants with high school or lower(P = 0.045). Patients with abnormal intracranial perfusion performed worse on the MMSE test(P = 0.024), and their WMS scores were significantly lower(P = 0.007). The MMSE scores and the memory quotients were significantly lower in patients with a history of cerebral infarction(MMSE, P = 0.047, memory quotient score, P = 0.018). Conclusion A history of cerebral infarction and abnormal cerebral perfusion are associated with decline in overall cognitive function and memory in patients with carotid stenosis. Being female and having an educational background above high school may be protective factors in the development of cognitive dysfunction.

Evaluation of the Protégé^(TM) stent in the treatment of carotid artery stenosis with adjunctive use of a filter Embolic Protection Device (PROCAR)-one-month follow-up data on 77 patients

Objective The trial was designed to evaluate the safety and performance of the ev3 Protégé TM stent in the treatment of de novo or re-stenotic common and/or internal carotid artery stenoses with adjunctive use of a CE-marked filter embolic protection device.Methods This study was a prospective multi-center, single-arm trial. Between June and October 2003, 77 patients were enrolled in 8 investigational centers throughout Europe. The primary endpoint was the incidence of Major Neurological Events (MANE) through one month. Other endpoints were the ability to properly place the stent, and primary patency and MANE after six months. Eligible for the study were patients with a de novo or restenotic target lesion located in the common and/or internal carotid artery (>70% stenosis for asymptomatic and >50% stenosis for symptomatic patients). The ev3 Spider (Embolic Protection Filter was used in 75 of 77 cases. Results In 76 out of the 77 patients (99%), the stent could be successfully implanted with a residual stenosis ≤30% as criterion. Of the 74 patients that had a carotid ultrasound at one month follow-up, none had a re-stenosis of the target lesion. There were three MANEs during or immediately after the procedure (3.9%), two were major and one was a minor stroke. There were eight severe complications (9.1%); six of these happened during or immediately after the procedure and were related to the procedure, none was related to the device. They are resolved without sequelae. No deaths have occurred.Conclusions The Protégé stent is safe and performs well in the treatment of carotid artery stenosis. The technical success rate for placement of the Protégé stent as assessed by the residual stenosis post implant was very high and all stents were successfully deployed. The incidence of MANE was comparable with that in other recent carotid stent studies and still lower than standard CEA.

Correlating cognitive impairment with carotid atherosclerosis and carotid artery stenosis in patients with acute cerebral infarction

BACKGROUND：Studies have demonstrated that carotid atherosclerosis and carotid artery stenosis are closely associated with cognitive impairment in patients with and without clinically evident cerebrovascular disease. OBJECTIVE： To investigate the correlation between the degree of pathological changes in carotid atherosclerosis, carotid artery stenosis, and cognitive impairment in patients with acute cerebral infarction through the use of color Doppler imaging. DESIGN, TIME AND SETTING： The present concurrent, non-randomized, controlled experiment was performed at the Departments of Neurology and Ultrasound, Affiliated Hospital of North Sichuan Medical College between November 2006 and August 2007. PARTICIPANTS： Fifty-five patients with cerebral infarction, consisting of 35 males and 20 females, aged 50–82 years, were admitted to the hospital between November 2006 and August 2007 and recruited for this study. An additional 30 subjects consisting of 18 males and 12 females, aged 47–78 years, that concurrently received a health examination at the same hospital, were also included as normal controls. METHODS： Intima-media thickness （IMT）, plaque shape, size, and echo intensity of all subjects were detected by color Doppler flow imaging. Assessment criteria： IMT 〉 1.0 mm was considered to be intimal thickening, and IMT 〉 1.2 mm was determined to be formed atherosclerotic plaques. In the position of the largest plaque, the degree of carotid artery stenosis was determined by the following formula： （1-cross-sectional area of residual vascular luminal area/vascular cross-sectional area） × 100%. Less than 30% exhibited mild stenosis, 30%-40% moderate stenosis, and 〉 50% severe stenosis. MAIN OUTCOME MEASURES： IMT and the degree of carotid artery stenosis were evaluated by color Doppler flow imaging. The Mini-Mental State Examination （MMSE）, as well as the clinical memory scale, was compared between patients with cerebral infarction and normal controls. RESULTS： In the cerebral infarction group, IMT was increased, the degree of carotid artery stenosis was aggravated, and the MMSE and MQ scores of clinical memory scale were decreased. In particular, orientation of time and place, attention, calculation, and short-time memory were decreased. There were statistically significant differences in MMSE and MQ of clinical memory scale between patients with cerebral infarction and normal controls （P 〈 0.01）. The scores from the two scales were significantly lower in patients with cerebral infarction with carotid plaque subgroup compared to the cerebral infarction with no carotid plaque subgroup （P 〈 0.01）. The scores from the two scales were also significantly lower in patients with IMT 〉 1.0 mm, as well as moderate and severe carotid artery stenosis, compared to patients with IMT ≤ 1.0 mm, and normal and mild stenosis group （P 〈 0.05）. CONCLUSION： More severe atherosclerotic and carotid artery stenosis leads to more obvious cognitive impairment.

Effect of the Wall Thickness of the Vessel on FFRCT of Carotid Artery Stenosis

Fractional flow reserve(FFR)computed from computed tomography angiography(CTA),i.e.,FFRCT has been used in the clinic as a noninvasive parameter for functional assessment of coronary artery stenosis.It has also been suggested to be used in the assessment of carotid artery stenosis.The wall thickness of the vessel is an important parameter when establishing a fluid-structure coupling model of carotid stenosis.This work studies the effect of the vessel wall thickness on hemodynamic parameters such as FFRCT in carotid stenosis.Models of carotid stenosis are established based on CTA image data using computer-aided design software.It is assumed that the vessel wall is a linear elastic and isotropic material,and the blood an incompressible Newtonian fluid.Under the pulsating flow condition,ANSYS Transient Structural and CFX are used to simulate the blood flow of fluid-structure coupling in the carotid stenosis model in order to obtain hemodynamic parameters and the corresponding FFRCT.The results show that when the elastic modulus of the vessel wall is fixed,FFRCT will decrease with the increase of the wall thickness.Similarly,FFRCT will decrease with the increase of the elastic modulus when the wall thickness is fixed.The difference in hemodynamic parameters such as FFRCT,however,is relatively small if the stiffness of the two models are close.The results demonstrate that the effect of the vessel wall thickness,especially for a model with small elastic modulus,should be taken into account in using FFRCT for functional assessment of carotid stenosis.Moreover,under the linear elasticity and isotropic material assumptions,the stiffness coefficient may replace the elastic modulus and wall thickness as a parameter reflecting material property of the vessel wall in the carotid stenosis model.

Effect of cold weather on carotid artery stenosis and occlusion:A retrospective observational study

Objective:To investigate the effect of cold weather on carotid artery stenosis and occlusion.Methods:We conducted a retrospective observational study,in which 145 patients with carotid artery stenosis and occlusion were enrolled[115 men and 30 women;the mean age was 61.08 years(95%CI 59.27-62.88)].Patients were divided into the low-temperature group(n=98)(≤12℃)and the non-low temperature group(n=47)(>12℃).Clinical characteristics,blood pressure,National Institutes of Health Stroke Scale(NIHSS),blood fat,and blood viscositys were compared between the two groups.Correlation between NIHSS and mean daily temperature was analyzed.Results:There was no significant difference in the systolic and diastolic blood pressure between the two groups(P>0.05).The NIHSS score was slightly higher in the non-low temperature group compared to that of the low-temperature group(U=2984,P<0.01).Glycemia,cholesterol level,prothrombin time,fibrinogen,and International Normalized Ratio did not show any significant difference(P>0.05).Correlation analysis showed a very low positive and statistically significant correlation between ambient temperature and NIHSS score(r=0.18,P=0.029).Conclusion:Cold weather does not impact blood pressure,blood cholesterol,and coagulation factors of patients with carotid artery stenosis and occlusion.The neurological deficit is more severe in the non-low ambient temperature group.A potential relationship exists between ambient temperature and the level of neurological impairment.

Synchronous carotid endarterectomy and coronary artery bypass graft: Four case reports

BACKGROUND One of the major perioperative complications for coronary artery bypass graft(CABG)is stroke.The risk of perioperative stroke after CABG is approximately 2%.Carotid stenosis(CS)is considered an independent predictor of perioperative stroke risk in CABG patients.The optimal management of such patients has been a source of controversy.One of the possible surgical options is synchronous carotid endarterectomy(CEA)and CABG.Here,we have presented 4 cases of successful synchronous CEA and CABG.Our center’s experience with 4 cases of significant carotid artery stenosis,which were successfully managed with combined CEA and CABG,are detailed.The first case was a female who presented for CABG after a ST-elevation myocardial infarction.She had right internal carotid artery(ICA)occlusion and 90%left ICA stenosis.The second case was a male who was electively admitted for CABG.It was discovered that he had left ICA occlusion and 90%right ICA stenosis.The third case was a male with a history of stroke,two months prior to admission.He presented with non-ST-elevation myocardial infarction.Preoperatively,it was discovered that he had>90%right ICA stenosis.The final case was a male who was electively admitted for CABG.It was discovered that he had bilateral>90%ICA stenosis.We have also reviewed the current evidence and guidelines for managing CS in patients undergoing CABG.CONCLUSION Our case series demonstrated that synchronous CEA and CABG was safe.A multicenter study with additional patients is needed.It is necessary for clinicians to screen for CS in high-risk patients with features.

CAS and CEA in the Treatment of Severe Internal Carotid Artery Stenosis

Objective:To explore the clinical value of carotid artery stent implantation(CAS)and carotid endarterectomy(CEA)in the treatment of patients with severe internal carotid artery stenosis.Methods:88 patients with severe carotid artery stenosis who underwent CAS and CEA in the First People's Hospital of Changde City(hereafter referred as "our hospital")from January 2018 to December 2020 were selected as the research objects and divided into CAS group(n=43)and CEA group(n=45).To understand the clinical application value and feasibility of the two surgical schemes by comparing the general situation,cerebral blood flow,MMSE scale,MOCA scale score and serum miR-145,IGF1R levels of the two surgical schemes.Conclusions:CAS and CEA in the treatment of patients with severe internal carotid artery stenosis,have good curative effect,can effectively improve the patient's cerebral blood flow,regulate serum miR-145,IGF 1R levels,promote the recovery of cognitive function,but relatively speaking,the incidence of stroke and hypotension after CAS is higher,and the incidence of hypertension after CEA is higher.

Relation between Carotid Artery Plaques Characteristics as a Predictor of Haemodynamics Changes after Carotid Artery Stenting

Objectives: To study relationship between carotid artery plaques characteristics and haemodynamic changes after carotid stenting. Patients and Methods: This observational prospective (pilot) study included 20 patients—who underwent CAS. The study was carried out in Ain shams university hospitals—Railway hospital (ERMED) and Suez insurance hospital from December 2018 to February 2020. Inclusion criteria, Symptomatic (defined as amaurosis fugax, TIA, Minor stroke or Major stroke) stenosis > 70%. Asymptomatic stenosis > 80% (accidentally discovered during pre-operative assessment for CABG and during full assessment for irrelevant stroke). Results: Regarding to plaque character for degree of stenosis, calcification and ulceration revealed significantly higher degree of stenosis in hemodynamic events group (P = 0.024). On the other hand, that there was no statistically significant difference between the two groups as regard calcification, ulceration and lesion location. Conclusion: The study revealed that HI is a common occurrence following CAS procedures and significantly higher degree of stenosis in hemodynamic events group. Plaque shape, ulcerations hardly affect haeodynamic instability after carotid stenting.

Update on Carotid Stenting and Endarterectomy

The role of carotid stenting and endarterectomy has been evolving over the past few decades. Results of recent randomized trials have added more insights to the indications of the two established interventions for symptomatic moderate to severe stenosis as well as asymptomatic carotid stenosis. Despite a wide range of complication rates in various trials for both symptomatic and asymptomatic carotid stenosis, benefits of the two interventions have been consistently demonstrated for symptomatic moderate stenosis as well as asymptomatic severe stenosis albeit with lower benefit margin for asymptomatic disease. Intervention for asymptomatic carotid stenosis should only be considered when the complication rate can be maintained below 3%.

Association between neutrophil-to-lymphocyte ratio and major postoperative complications after carotid endarterectomy:A retrospective cohort study

BACKGROUND Carotid artery cross-clamping during carotid endarterectomy(CEA)may damage local cerebral perfusion and induce cerebral ischemia–reperfusion injury to activate local inflammatory responses.Neutrophil-to-lymphocyte ratio(NLR)is an indicator that reflects systemic inflammation.However,the correlation between NLR and complications after CEA remains unclear.AIM To investigate the association between NLR and major complications after surgery in patients undergoing CEA.METHODS This retrospective cohort study included patients who received CEA between January 2016 and July 2018 at Beijing Tiantan Hospital.Neutrophil and lymphocyte counts in whole blood within 24 h after CEA were collected.The primary outcome was the composite of major postoperative complications including neurological,pulmonary,cardiovascular and acute kidney injuries.The secondary outcomes included infections,fever,deep venous thrombosis,length of hospitalization and cost of hospitalization.Statistical analyses were performed using EmpowerStats software and R software.RESULTS A total of 224 patients who received CEA were screened for review and 206 were included in the statistical analyses;of whom,40(19.42%)developed major postoperative complications.NLR within 24 h after CEA was significantly correlated with major postoperative complications(P=0.026).After confounding factors were adjusted,the odds ratio was 1.15(95%CI:1.03–1.29,P=0.014).The incidence of major postoperative complications in the high NLR group was 8.47 times that in the low NLR group(P=0.002).CONCLUSION NLR is associated with major postoperative complications in patients undergoing CEA.

Evaluation of ischemic lesions after carotid artery stenting with diffusion-weighted imaging

BACKGROUND Almost 90%of cerebral thromboembolism cases are caused by atherosclerosis.Craniocervical atherosclerosis is often observed at the carotid bifurcation and is responsible for 20%-30%of all stroke cases.The course of atherosclerotic carotid artery stenosis varies depending on the grade of stenosis and characteristics of the plaque.Carotid artery stenting(CAS)can be used as a less invasive method in patients with symptomatic and asymptomatic high-grade carotid artery stenosis.Diffusion-weighted imaging(DWI)is an effective method for detection of silent or symptomatic acute ischemic lesions that may arise due to CAS or carotid endarterectomy.The number and volume of new ischemic lesions are determined using DWI.AIM To evaluate the number and volume of ischemic lesions and their cerebral parenchymal and vascular distribution after CAS using DWI.METHODS Forty-seven male(73.4%)and seventeen female(26.6%)patients(total,n=64)aged 42-84 years(mean 67.96±8.03 years)diagnosed with carotid stenosis between October 2006 and July 2012 were included in this retrospective study.Twelve of the cases(18.8%)were asymptomatic,while fifty-two(81.2%)were symptomatic.The area where the stenosis was highest was measured,and the stenosis rate was determined using the North American Symptomatic Carotid Endarterectomy Trial method.DWI of the cases was evaluated by two radiologists experienced in neuroradiology(B.A.with more than 15 years of experience,E.G.with more than 10 years of experience).Routine DWI examinations were carried out by a 1.5 T MR device 1 h before and after the operation.Since the ischemic lesions that developed in the first hour and in the follow-up period of 5-24 h were assumed to be due to CAS,all lesions within the first 24 h were considered as new ischemias.RESULTS In the present study,39 new ischemic lesions were detected in 20 cases.The average number of new lesions after all CAS operations was 0.62.They were mostly located in the occipital lobes,followed by the frontal and parietal lobes.These new ischemic lesions were most common in the middle cerebral artery territory,followed by the posterior cerebral artery territory and middle cerebral artery-posterior cerebral artery watershed areas.New lesions were found in 31.2%(20/64)of patients,including 17(26.5%)in ipsilateral and three(4.6%)in contralateral hemispheres.New bilateral lesions were detected in one case(1.5%).The average volume of the new ischemic lesions detected by the two observers was 1.10 cm³.The numbers of newly appearing ischemic lesions in DWI after CAS were significantly higher in cases where stenting was applied on the left side of the carotid artery and in cases where longer plaques(>1 cm)were responsible for the narrowing in symptomatic patients.The stenosis rate was low in the group with ulcerated plaques.CONCLUSION New ischemic lesions due to CAS appear mostly in the main arterial territory but they may also occur in watershed areas.

Acute carotid stent thrombosis:A case report and literature review

BACKGROUND Acute carotid stent thrombosis(ACST)is a rare but devastating complication in the carotid artery stenting(CAS)procedure.The aim of this article is to report a case and review cases of ACST reported in the literature,and investigate risk factors and management strategies for ACST.CASE SUMMARY We reviewed the treatment process of a patient with ACST after CAS.Then multiple databases were systematically searched to identify studies reporting ACST from 2005 to 2020.The demographic data,risk factors,treatment strategies,and prognosis were extracted and analyzed.CONCLUSION The reason for ACST is multifactorial.Proper patient selection,normative antiplatelet treatment,and perfect technical detail may decrease the incidence of ACST.Several treatment strategies such as thrombolysis,mechanical thrombectomy,and open surgery may be options for the treatment of ACST.Limited data have shown that carotid endarterectomy is effective with favorable results.

Multidimensional modeling of the stenosed carotid artery: A novel CAD approach accompanied by an extensive lumped model

This study describes a multidimensional 3D/lumped parameter（LP） model which contains appropriate inflow/outflow boundary conditions in order to model the entire human arterial trees. A new extensive LP model of the entire arterial network（48 arteries） was developed including the effect of vessel diameter tapering and the parameterization of resistance, conductor and inductor variables. A computer aided-design（CAD） algorithm was proposed to effciently handle the coupling of two or more 3D models with the LP model, and substantially lessen the coupling processing time. Realistic boundary conditions and Navier-Stokes equations in healthy and stenosed models of carotid artery bifurcation（CAB） were used to investigate the unsteady Newtonian blood flow velocity distribution in the internal carotid artery（ICA）. The present simulation results agree well with previous experimental and numerical studies. The outcomes of a pure LP model and those of the coupled 3D healthy model were found to be nearly the same in both cases. Concerning the various analyzed 3D zones, the stenosis growth in the ICA was not found as a crucial factor in determining the absorbing boundary conditions.This paper demonstrates the advantages of coupling local and systemic models to comprehend physiological diseases of the cardiovascular system.

Transcervical access,reversal of flow and mesh-covered stents:New options in the armamentarium of carotid artery stenting

In the last 25 years, the very existence of carotid artery stenting(CAS) has been threatened on a number of occasions. The initial disappointing results that even lead to the discontinuation of an early randomized controlled trial have improved considerably with time. Novel devices, advanced stent and equipment technology, alternative types of access and several types of filters/emboli protecting devices have been reported to reduce stroke/death rates during/after CAS and improve CAS outcomes. The present review will provide a description of the various technology advances in the field that aim to reduce stroke and death rates associated with CAS. Transcervical access, reversal of flow and mesh-covered stents are currently the most promising tools in the armamentarium of CAS.