Utilization of Intravascular Ultrasound during Carotid Artery Stenting

For patients at high risk for surgery, carotid artery stenting (CAS) is a viable alternative to help reduce risk of stroke for patients with high-grade carotid artery stenosis; however, a higher incidence of perioperative stroke has been observed in patients undergoing stenting compared to those undergoing open surgery. Intravascular ultrasound (IVUS) is commonly used during coronary artery procedures to help evaluate lesions and to guide stent placement. Multiple groups have sought to determine whether IVUS could also be used during CAS. While IVUS has been shown to be both feasible and safe during CAS, there is limited evidence that demonstrates direct improvement in procedural outcomes. Further studies focusing on clinical outcomes should be conducted in order to justify routine use of this technology during CAS.     

Intra-aortic counterpulsation during carotid stenting.

Postprocedural hypotension following endovascular stent placement of carotid artery disease (CAS) predicts increased in-hospital complications and long-term risk of death. Intra-aortic balloon counterpulsation (IABP) both increases mean arterial pressure and cerebral blood flow and therefore possibly reduces complications due to hemodynamic instability during and after CAS. In this study, we describe the use of IABP in a patient with severe depression of left ventricular function due to diffuse coronary artery disease undergoing CAS. Controlled studies are necessary to demonstrate a potentially protective role of IABP in high-risk CAS patients.     

Optimal treatment of carotid artery disease

Extracranial carotid artery disease accounts for approximately 25% of ischemic strokes. Although carotid endarterectomy (CEA) is the established gold standard for carotid revascularization, carotid artery angioplasty and stenting (CAS) is continually developing into a safer and more efficacious method of stroke prevention. Embolic protection, improving stent designs, and ever-increasing surgeon experience are propelling CAS towards equipoise with and possible superiority to CEA. One multicenter randomized trial and several nonrandomized registries have successfully established CAS as an accepted treatment for high-risk patients. Clinicians must strive to perform well-designed clinical trials that will continue to aid understanding and improve application of both endovascular and open techniques for extracranial carotid revascularization. We review the data published to date regarding the indications for and recent developments in the use of CAS.     

Assessment of Carotid Artery Stenosis and the Use of Statins

General thinking has previously centered on managing carotid artery stenosis (CAS) by carotid endarterectomy and subsequently, stenting for higher risk patients. However for CAS and other forms of vascular disease, especially when asymptomatic, there is new emphasis on defining underlying mechanisms. Knowledge of these mechanisms can lead to medical treatments that result in possible atherosclerotic plaque stabilization, and even plaque regression, including in the patient with CAS. For now, the key medication class for a medical approach are the statins. Their use is supported by good cardiovascular clinical trial evidence including some directed carotid artery studies, especially with a demonstrated decrease in carotid intima-media thickness. Procedural controversy still exists but the current era in medicine offers significant support for medical management of asymptomatic CAS while techniques to recognize the vulnerable plaque evolve. If CAS converts to a symptomatic status, early referral for endarterectomy or stenting is indicated.     

Protected carotid artery stenting in patients with severe stenosis

Intraplaque hemorrhage (IPH) and ulcers are the major findings of unstable plaques. In addition, initial symptoms are associated with postprocedural complications after carotid artery stenting (CAS). The aim of this study was to determine the safety of CAS using an embolic protection device in symptomatic patients with severe carotid artery stenosis and unstable plaques such as IPH and ulcers.This retrospective study included 140 consecutive patients with severe carotid stenosis. These patients underwent preprocedural carotid vessel wall imaging to evaluate the plaque status. We analyzed the incidence of initial clinical symptoms, such as headache, nausea, and vomiting, after CAS. The primary outcomes analyzed were the incidence of stroke, myocardial infarction, and death within 30 days of CAS.Sixty-seven patients (47.9%) had IPH, and 53 (38.9%) had ulcers on carotid wall imaging/angiography. Sixty-three patients (45.0%) had acute neurological symptoms with positive diffusion-weighted image findings. Intraluminal thrombi on initial angiography and flow arrest during CAS were significantly higher in patients with IPH and symptomatic patients. Symptoms were significantly higher in patients with IPH than in those without (63.5% vs 35.1%, P < .001). There were no significant differences in clinical symptoms after stenting or in primary outcomes, regardless of IPH, ulcer, or initial symptoms.IPH and plaque ulceration are risk factors in symptomatic carotid stenosis. However, IPH and plaque ulceration were not a significant risk factors for cerebral embolism during protected carotid artery stent placement in patients with carotid stenosis. Protected CAS might be feasible and safe despite the presence of unstable plaques.     

Carotid Artery Stenting–Historical Context,Trends, and Innovations

Surgical carotid endarterectomy (CEA) has been proven effective in both primary and secondary stroke prevention and, until recently, has been considered the standard treatment approach for patients with severe carotid artery disease. Because of its technical limitations and less favorable outcomes, carotid artery stenting (CAS) has been offered preferably to patients considered to be too comorbid to undergo surgical treatment. However, CAS has evolved over time into a reliable method and is currently considered an alternative to CEA. The aim of this review was to discuss the historical aspects, trends, and innovations in CAS.     

颈动脉内膜切除术和支架置入术后再狭窄的诊断和治疗

作为一种经典的血管重建方式,颈动脉内膜切除术(carotid endarterectomy,CEA)已被广泛用于颅外颈动脉重度狭窄的治疗.近年来,颈动脉支架置入术(carotid artery stenting,CAS)已有逐步取代CEA的趋势.大量临床研究发现,除围手术期并发症外,CEA和CAS后颈动脉再狭窄对患者的预后也具有重要影响.文章就CEA和CAS术后再狭窄的诊断和治疗研究现状做了综述.     

Safety and utility of intravascular ultrasound-guided carotid artery stenting.

Intravascular ultrasound (IVUS) is useful in evaluating coronary stent deployment. The aim of this study was to assess the safety and utility of IVUS in carotid artery stenting (CAS). Ninety-eight consecutive high-risk patients (107 arteries) underwent CAS. IVUS was performed prior to predilatation in 87 of the 107 vessels and in all 107 following stent deployment when an optimal angiographic appearance was obtained. Quantitative carotid angiography (QCA) and IVUS analysis were performed offline. Procedural success was 97%. Combined stroke or death at 30 days was 5.6%. IVUS measurements of the minimum lumen diameter (MLD) of the distal internal carotid artery (ICA) reference segment were similar to QCA (4.60 +/- 0.74 vs. 4.74 +/- 0.71 mm; P = 0.21). The ICA stent MLD was significantly smaller by IVUS compared to QCA (3.65 +/- 0.68 vs. 4.31 +/- 0.76 mm; P < 0.001). IVUS detected stent malapposition in 11%. IVUS findings, after an optimal angiographic result, necessitated additional treatment in 9% of procedures. Calcium was detected in more arteries with IVUS than angiography (61% vs. 46%; P < 0.05). Arteries with superficial lesion calcification subtending three or four quadrants by IVUS had a 31% incidence of stroke compared with a 1% incidence in arteries without severe superficial calcium (P < 0.001). We found IVUS imaging in CAS to be safe even prior to plaque dilatation. IVUS provides a more accurate assessment of stent dimensions, expansion, and apposition than angiography. Severe calcification by IVUS was associated with a higher risk of stroke.     

Guidelines for patient selection and performance of carotid artery stenting

The endovascular treatment of carotid atherosclerosis with carotid artery stenting (CAS) is controversial. The inter-collegiate Carotid Stenting Guidelines Committee (CSGC) recommends that CAS should not be performed in the majority of patients requiring carotid revascularization. CAS may be considered for specific high risk patients with symptomatic severe carotid stenosis who have contraindications for carotid endarterectomy, or in those under 70years of age where carotid re-vascularization is considered appropriate. Advances in endovascular technologies and the long-term results of randomized controlled trials will guide future revisions of these guidelines.     

Ultrasound velocity criteria for carotid in-stent restenosis.

OBJECTIVE: To examine duplex ultrasound (US) criteria for carotid in-stent restenosis (ISR). BACKGROUND: Carotid artery stent (CAS) placement is an alternative to surgery for the treatment of carotid stenosis in high surgical risk patients. US is the primary method used to follow carotid stent patency. This study investigates US velocity measurements in carotid ISR. METHODS: Two hundred sixty consecutive patients with CAS placement from June 2000 to June 2004 were followed with serial US. ISR was determined by using the standard US velocity criteria for nonstented carotid artery using peak systolic velocity (PSV), end-diastolic velocity (EDV), and internal carotid artery to common carotid velocity ratio (ICA/CCA ratio). Patients suspected of having carotid ISR > or =50% by US, underwent invasive angiography with stenosis graded by NASCET criteria. Results were compared to patients with nonstented carotid artery stenosis using Two-tailed Student's t-test. RESULTS: PSV and ICA/CCA ratio increased to a greater degree in ISR. In 50-69% stenotic arteries, the mean ICA/CCA ratio was 2.76 +/- 0.7 in the ISR group compared to 2.04 +/- 0.3 in the nonstented carotid group (P < 0.05). In > or =70% stenotic arteries, there were increases in PSV (520 +/- 93 vs. 362 +/- 60, P < 0.05) and ICA/CCA ratio (7.58 +/- 2 vs. 4.51 +/- 1.3, P < 0.05) in ISR versus nonstented carotid arteries, respectively. CONCLUSION: PSV and ICA/CCA ratio in ISR increased to a greater extent for angiographic stenosis > or =50%. PSV 240 cm/sec and ICA/CCA ratio 2.45 are optimal thresholds for > or =50% ISR, and PSV 450 cm/sec and ICA/CCA ratio 4.3 are optimal thresholds for > or =70% ISR.     

Carotid artery revascularization with distal protection in high‐surgical‐risk patients in routine clinical practice: Rationale and design of the CABANA safety surveillance program

Background: Continuous improvement in carotid artery stenting (CAS) outcomes, especially for periprocedural death and stroke in high‐surgical‐risk patients, have been seen in recent randomized trials of CAS versus carotid endarterectomy and CAS registries. However, these studies use stringent inclusion/exclusion criteria for patient, institution, and physician selection. The Carotid Stenting Boston Scientific Surveillance Program (CABANA) study was initiated to evaluate periprocedural outcomes with modern versions of the Carotid Wallstent and FilterWire EZ System for operators with a wide range of clinical specialties, CAS experience and training levels, in patients with a broad range of high‐surgical‐risk conditions and lesion types. Methods: This prospective, single‐arm study enrolled 1,097 subjects with 1,098 carotid artery lesions at 99 study centers. Investigators were grouped into one of three tiers according to whether they had a high, medium, or low level of previous CAS experience and were also categorized by their CAS‐credential‐based training requirements for the CABANA study. Follow‐up at 30 days includes clinical evaluation and independent neurological and NIH stroke scale assessments. The primary endpoint rate of 30‐day composite stroke, death, and MI, as well as the rates of these individual events, will be evaluated across the overall study, by physician experience tier, and by physician training tier. Discussion: The evaluation of periprocedural CAS safety in a real‐world environment with modern devices in high‐surgical‐risk patients treated by physicians with a broad range of training and experience will better inform treatment decisions in the future. © 2011 Wiley Periodicals, Inc.     

Treatment strategies for carotid stenosis in patients at increased risk for surgery

The purpose of carotid revascularization is stroke prevention. The merits of carotid revascularization as well as the type of revascularization are dependent on the “natural risk” and the “revascularization risk.” In general, the natural risk of stroke in any patient with carotid stenosis (CS) is dependent on the symptomatic status of the patient and CS severity. Contemporary choices for carotid revascularization include carotid endarterectomy (CEA) and carotid artery stenting (CAS). Anatomical (hostile neck situations, severe bilateral CS, CEA restenosis) and clinical (severe cardiopulmonary diseases, prior cranial nerve injury) factors may increase the risk of CEA. Likewise, anatomical (complex aortic arch and brachiocephalic arterial anatomy, presence of thrombus, and heavy calcification) and clinical (need for heart surgery within 30 days) factors may increase the risk of CAS. Other factors such as the presence of symptomatic CS (transient ischemic attack or stroke within 6 months), decreased cerebral reserve, chronic kidney disease, and age older than 75 years may increase the risk of CEA and CAS. In general, symptomatic patients with severe CS exceed revascularization risk. In contrast, asymptomatic patients who are high risk for CEA should be considered for CAS because the natural risk of stroke should undergo careful assessment of baseline cognitive function, aortic arch and carotid artery anatomy, and likelihood of survival for 3 years. Patients who have normal cognitive function, favorable anatomy, and high likelihood of survival more than 3 years should be considered for CAS, whereas patients with multiple unfavorable features may be treated with optimal medical therapy, without revascularization.     

Hybrid技术治疗冠心病合并严重颈动脉狭窄的临床疗效及安全性研究

目的回顾性分析颈动脉支架术(CAS)和冠状动脉旁路移植术(CABG)同期或分期Hybrid技术治疗冠心病合并严重颈动脉狭窄的临床疗效及安全性。方法入选2008年7月至2014年9月期间中国医学科学院阜外医院成人心脏外科收治的同期或分期实施CAS和CABG的冠心病合并严重颈动脉狭窄患者274例,依据两种手术是否同期实施分为两组:同期手术组(间隔≤7 d,n=35)和分期手术组(间隔7 d,n=239)。对两组患者的临床资料及预后进行比较分析。结果与同期手术组相比,分期手术组患者的搭桥数量、颈动脉支架植入个数以及肾动脉支架植入个数显著增加,而呼吸机辅助时间显著减少,差异均具有统计学意义(P0.05)。中位随访时间为45.6(28.1~65.4)个月,随访期间仅1例患者发生脑卒中而死亡。两组患者围手术期不良事件发生率间差异无统计学意义(P0.05)。截至随访终期,Cox模型分析结果显示,是否同期手术与患者复合终点事件发生率无明显相关性(OR=0.679,95%CI:0.12~3.72;P=0.66)。结论 CAS联合CABG是治疗冠心病合并严重颈动脉狭窄的一种安全、有效的微创策略。     

颈动脉支架与内膜切除术治疗颈动脉狭窄疗效和安全性的Meta分析

目的 系统评价颈动脉支架(carotid artery stenting,CAS)和颈动脉内膜切除术(carotid endarterectomy,CEA)治疗颈动脉狭窄的安全性和疗效.方法 计算机检索PubMed、EMbase、Cochrane图书馆临床对照试验资料库、中国期刊全文数据库(CNKI)、中文科技期刊数据库(VIP)以及万方医学数据库,并辅以手工检索,收集CAS和CEA治疗颈动脉狭窄的随机对照试验,采用Cochrane协作网提供的RevMan 5.0.24软件进行Meta分析.结果 共纳入12个研究,6903例患者,其中CAS组3460例,CEA组3443例.CAS组术后30 d脑卒中或死亡联合发生风险(RR=1.64,95%CI:1.33～2.03,P＜0.00001)以及脑卒中风险(RR=1.70,95%CI:1.34～2.14,P＜0.00001)高于CEA组;CEA组术后30 d心肌梗死风险(RR=0.62,95%CI:0.39～0.97,P=0.04)和颅神经损伤风险(RR=0.07,95%CI:0.03～0.16,P＜0.00001)高于CAS组;两组术后30 d死亡风险(RR=1.33,95%CI:0.78～2.28,P=0.29)、致残性脑卒中风险(RR=1.27,95%CI:0.82～1.96,P=0.29)和术后1年脑卒中或死亡联合发生风险(RR=0.96,95%CI:0.63～1.46,P=0.84)差异无统计学意义.结论 从安全性方面考虑,对于一般手术风险的颈动脉狭窄患者,CEA仍是治疗颈动脉狭窄的首选治疗手段.具有手术高危因素或不适合手术的患者,CAS治疗更具有优势.

Abstract：

Objective To compare the safety and efficacy of carotid artery stenting (CAS) and carotid endarterectomy(CEA) for the treatment of carotid stenosis. Methods The electronic databases (PubMed, EMbase, Cochrane Central Register of Controlled Trials, CNKI, VIP and Wanfang) were searched in order to retrieve randomized controlled trials (RCTs) about comparing CAS and CEA for the treatment of carotid stenosis. Cochrane collaboration's RevMan 5.0.24 were used for analyzing data. Results Twelve RCTs totalling 6903 patients (3460 patients were randomized to CAS and 3443 randomized to CEA) with symptomatic or asymptomatic stenosis were included in the meta-analysis. There were significantly higher 30-day relative risks after CAS than after CEA for death or any stroke [RR=1.64, 95%CI (1.33-2.03), P＜0.00001] and for stroke [RR=1.70, 95%CI (1.34-2.14), P＜0.00001]. The relative risks of myocardial infarction [RR=0.62, 95%CI (0.39-0.97), P=0.04] and cranial neuropathy [RR=0.07, 95%CI (0.03-0.16), P＜0.00001] was significantly less after CAS than after CEA. The relative risks of death [RR=1.27, 95%CI (0.82-1.96), P=0.29] or disabling stroke within 30 days [RR=1.33, 95%CI (0.78-2.28), P=0.29] and any stroke or death at 1 year after the procedures [RR=0.96, 95%CI (0.63-1.46), P=0.84] did not differ significantly between CAS and CEA operation. Conclusions CEA remains the first choice for treatment of carotid stenosis for patients with low surgery risk. For patients with high surgery risk and unsuitable for surgery, CAS has more advantages. It is reasonable to view CAS and CEA as complementary rather than competing modes of therapy.     

Screening for carotid artery disease before cardiac surgery: Is current clinical practice evidence based?

BACKGROUND: There is no clear consensus as to the correct screening procedure to identify patients undergoing cardiac surgery and who are at greatest risk of stroke because of the presence of significant carotid artery stenosis. Such screening is important because some patients benefit from combined carotid and cardiac surgery and, regardless of this, the information gained puts the cardiac surgeon in a position to provide an accurate assessment of surgical risk. Our objective was to examine current clinical practice of carotid artery investigation prior to urgent cardiac surgery and to review this illustrative practice in the context of the world literature. HYPOTHESIS: The study aimed to establish that current typical practice for screening cardiac surgical patients for carotid artery disease is illogical according to the evidence in the world literature. METHODS: The study consisted of a retrospective assessment of all patients undergoing urgent cardiac surgery and a Medline-derived literature review, and included all patients undergoing urgent cardiac surgery at a tertiary cardiothoracic center between January 1 and December 31, 1997. RESULTS: Of 529 patients undergoing urgent cardiac surgery, 44 (8%) were screened preoperatively by duplex Doppler ultrasonography for carotid disease. The indications for screening were asymptomatic carotid bruit in 24 patients, history of stroke or transient ischemic attack (TIA) in 12 patients, and neither stroke, TIA, or bruit in 7 patients. The tests were requested either by the attending cardiologists or by the cardiac surgeon to whom they were referred. One patient had already been diagnosed as having carotid artery disease in the past. Thirteen patients underwent additional carotid investigations. Eleven patients were demonstrated to have internal carotid artery stenosis > or = 60% and 3 patients underwent combined cardiac and carotid surgery. Review of the literature revealed the following groups to be at increased risk of future stroke unrelated to surgery, and of postoperative stroke: those with a history of stroke or TIA, those with carotid bruits, and, of importance, all patients with significant carotid stenosis. Recent data suggest that symptomatic patients and the elderly are at greatest risk. CONCLUSIONS: Only 8% of patients undergoing urgent cardiac surgery in a 1-year period were screened for carotid artery disease. We suggest that screening should definitely be performed in all patients with a history of stroke or TIA, all patients with a bruit, and all patients aged > 65 years. The literature suggests, however, that significant reductions in stroke rate could be achieved by screening the whole cardiac surgical population, although there is a paucity of data that are specifically pertinent to this patient subgroup. Further data are therefore required for the construction of a scientifically valid and medicolegally sound policy.     

What's happening in carotid stent? A case report of prominent plaque protrusion after carotid artery stenting observed on angioscopy

Thromboembolic complications after carotid artery stenting (CAS) remain an unsolved problem, and several intravascular imaging tools have been proposed to clarify the mechanism of these complications. We report a case of intraprocedural plaque protrusion revealed by angioscopy. A 64-year-old woman underwent CAS for left carotid artery stenosis. After stent placement, optical frequency domain imaging demonstrated some plaque protrusion, and angioscopy showed prominent mobile plaque fragments protruding into the vessel between stent struts and confirmed the coverage of the protruded plaque after the overlapping stent was placed. Compared with other tools, angioscopy more clearly revealed plaque protrusion in the vessel after CAS.     

Carotid artery angioplasty and stenting in elderly patients： the advantage of being an interventional cardiologist

Objective Carotid angioplasty and stenting （CAS） has been suggested to be the procedure of choice in patients with high risk cardiovascular profile. Unfortunately, such patients are often aged with several comorbidities, such as a high prevalence of coronary artery disease, peripheral artery disease and hostile anatomy that complicate the CAS performance. We sought to evaluate the results of CAS in elderly patients, outlining the encountered challenges and the eventual proposed global cardiovascular management. Methods We retrospectively searched the database for patients 〉 65-year-old who were referred to Cardiovascular Diagnosis and Endoluminal Interventions, Rovigo General Hospital, over a 24-month period （December 2007-November 2009） for CAS. Coronary angiography and peripheral screening were performed in all patients. All eventual challenges and related solutions were analyzed. Results Totally, 160 patients were enrolled. Among which, 50 patients （31.2%, mean age 80 ~ 6.4 years） underwent CAS over a 24- month period： 24 patients （48%） had concurrent coronary artery disease （three-vessel in 7 patients, bivessel in 8 patients, single vessel in 5 patients and left main in 4 patients）; 13 patients （26%） and peripheral artery disease at the site of arterial access; 15 patients and type III aortic arch （30%）, 7 patients severe tortuosity of the common carotid artery （14%）, and 8 angulated takeoffof carotid or internal artery （16%）. Concurrent percutaneous coronary intervention was performed in 14 patients, including 3 patients with left main disease. Concurrent peripheral intervention was performed in 7 patients （ all with bilateral common or external critical disease） due to the impossibility to gain another access. Successful carotid cannulation was achieved in all patients with hostile neck. Two-wire technique has been used in 17 patients, three-wire technique in 9 patients, and four-wire technique in 4 patients. Conclusion Elderly patients submitted to CAS represent a complex and challenging subgroup in which often cardiac and peripheral technical expertise is required to gain success of the procedure： interventional cardiologists are probably the preferred performers in such complex patients （JGeriatr Cardio12010; 7：3-6）.     

An evidence‐based review of the impact of periprocedural myocardial infarction in carotid revascularization

Landmark trials comparing carotid endarterectomy (CEA) with medical therapy in patients with symptomatic or asymptomatic atherosclerotic stenosis of extracranial carotid arteries have favored carotid revascularization. Carotid artery stenting (CAS) has emerged as a minimally invasive option for revascularization of carotid artery stenoses and has been shown to be noninferior to CEA, regardless of patient symptom status. Debate continues regarding the importance of periprocedural myocardial infarction (PMI) as an endpoint in carotid revascularization trials. Recent randomized comparisons of CEA and CAS pre‐specify PMI as an endpoint. Understanding PMI in CEA and CAS, the need for routine biomarker assessment surrounding both revascularization strategies, the effect of PMI on long‐term morbidity and mortality, and the groups most at risk for PMI are of critical importance when choosing a carotid revascularization strategy for symptomatic and asymptomatic patients, since decreasing the incidence of PMI will make revascularization safer. This review examines available data regarding the relevance of PMI in vascular and carotid‐specific outcomes. © 2013 Wiley Periodicals, Inc.     

Carotid Endarterectomy: Current Concepts and Practice Patterns

Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon.