Search

Stroke remains among the leading causes of disability and death worldwide. Fibrinolytic therapy is associated with poor patency and functional outcomes. Recently, multiple randomized trials have been published that have consolidated the role of endovascular therapy for ischemic stroke due to large vessel occlusion in the anterior cerebral circulation. This manuscript reviews the current understanding of the endovascular management of acute stroke including technical aspects and current evidence base.

Successful open and endovascular carotid artery intervention depends on a thorough foundational knowledge of cervical and intracranial vascular anatomy. It is essential for the carotid interventionist to be familiar with the common and rare variants of the cervical and intracranial vasculature, and to understand the implications of these variants for the performance of carotid intervention with protection of the distal circulation. This article provides interventionists with a basic description of the normal and relevant variant vascular anatomy from the aortic arch to the circle of Willis, and outlines the potential difficulties that specific variants may present for endovascular therapy.

Stroke is the third leading cause of death and the most common cause of long-term disability in the USA. Approximately 25% of strokes are due to carotid artery disease. The mechanisms of stroke include thrombotic occlusion, thrombus embolism, atheroembolism and dissection or subintimal hematoma. Today, endarterectomy is the standard of care for management of significant carotid artery disease. The SAPPHIRE trial has proved the noninferiority of carotid artery stenting versus carotid endarterectomy in ‘high-risk’ patients, which led to the US FDA approval of carotid stent for high-risk patients. The CREST trial is the largest randomized trial comparing stenting versus endarterectomy and showed no significant difference in death, stroke or myocardial infarction. Over the last 15 years, the accumulation of experience, the improvement of stent platforms and embolic protection devices, and the strong demand from patients for a less invasive alternative to carotid endarterectomy has made carotid artery stenting an equally efficient and safe procedure for the prevention of stroke.

Assessment and treatment plan for asymptomatic patients with carotid stenosis are based on angiography at the present time. However, angiography or other imaging modalities are limited with their resolution to detect high-risk plaque features. Intravascular optical coherence tomography (IVOCT) recently emerged as a novel imaging modality with a unique resolution to identify vulnerable plaque characteristics. We report use of IVOCT in two separate asymptomatic patients with carotid stenosis with two different plaque types.

To compare the performance in vitro of 6 distal protection filters (DPFs) on the basis of filtration ability and effects on pressure gradient and vascular impedance in a flow model of the internal carotid artery (ICA).Six DPFs (Accunet, Angioguard, FilterWire, Gore Embolic Filter, NAV6, and SpiderFX) were evaluated in a physiologically realistic flow loop. A blood analog was heated to body temperature and circulated by a pulsatile pump outputting a time-varying flow rate representative of the ICA. The ICA flow model was a highly curved tube representing a challenging site for filter deployment. The DPFs were deployed at the apex of the curved segment, and 2 sizes of microspheres (143 and 200 µm) were injected to simulate embolization. The capture efficiency, pressure gradient, normalized pressure gradient, and vascular impedance were calculated.The Gore filter had high capture efficiency (143 µm: 99.97%; 200 µm: 100.00%) with relatively small increases in pressure gradient (143 µm: +27%; 200 µm: +20%) and vascular impedance (143 µm: +23.4%; 200 µm: +6.1%) after particles were injected. Spider had the lowest capture efficiency (143 µm: 1.50%; 200 µm: 19.34%, p0.0005), while NAV6 (143 µm: +916%, p0.0005) and Accunet (200 µm: +179%, p0.0005) yielded the largest pressure gradient increases.A bench-top flow apparatus exhibiting physiologically realistic conditions was developed by combining pulsatile flow and a body temperature blood analog. Using microspheres larger than the pore size of most of the DPFs, the device-wall apposition has an important effect on the overall filter performance and the global fluid dynamics in the flow model.

The majority (>80%) of the three-quarters of a million strokes that will occur in the United States this year are ischemic in nature. The treatment of acute ischemic stroke is very similar to acute myocardial infarction, which requires timely reperfusion therapy for optimal results. The majority of patients with acute ischemic stroke do not receive any form of reperfusion therapy, unlike patients with acute myocardial infarction. Improving outcomes for acute stroke will require patient education to encourage early presentation, an aggressive expansion of qualified hospitals, and willing providers and early imaging strategies to match patients with their best options for reperfusion therapy to minimize complications.

Cystic fibrosis (CF) is a recessive genetic disease characterized by dehydration of the airway surface liquid and impaired mucociliary clearance. As a result, individuals with the disease have difficulty clearing pathogens from the lung and experience chronic pulmonary infections and inflammation. There may be intermittent pulmonary exacerbations or acute worsening of infection and obstruction, which require more intensive therapies. Hemoptysis and pneumothorax are complications commonly reported in patients with cystic fibrosis.This document presents the CF Foundation's Pulmonary Therapies Committee recommendations for the treatment of hemoptysis and pneumothorax.The committee recognized that insufficient data exist to develop evidence-based recommendations and so used the Delphi technique to formalize an expert panel's consensus process and develop explicit care recommendations.The expert panel completed the survey twice, allowing refinement of recommendations. Numeric responses to the questions were summarized and applied to a priori definitions to determine levels of consensus. Recommendations were then developed to practical treatment questions based upon the median scores and the degree of consensus.These recommendations for the management of the patient with CF with hemoptysis and pneumothorax are designed for general use in most individuals but should be adapted to meet specific needs as determined by the individuals, their families, and their health care providers. It is hoped that the guidelines provided in this manuscript will facilitate the appropriate application of these treatments to improve and extend the lives of all individuals with cystic fibrosis.

Carotid artery stenting has gained popularity due to its minimally invasive approach. However, several design concerns preclude the successful use of carotid stents. Technical issues, such as open versus closed cells, scaffolding, trackability, foreshortening, and changes in local geometry and hemodynamics, affect stent performance. Previous clinical and experimental studies have evaluated current stent models while proposing and testing novel stent designs. This review focuses on the technical aspects of carotid stent design and the clinical significance of key design parameters identified via computational and experimental modeling.

Purpose To assess in vitro performance of four embolic protection filters (EPFs) with a varying mass of injected particles. Evaluation is based on capture efficiency, pressure gradient, flow rate, and vascular resistance. Materials and Methods A bench-top flow apparatus was used for in vitro testing of four devices (Spider RX, FilterWire EZ, RX Accunet, and Emboshield). A silicone phantom with average human carotid artery dimensions and a 70% symmetric internal carotid artery (ICA) stenosis was used to model the carotid bifurcation. A blood-mimicking solution (glycerol/deionized water) was circulated at the time-averaged mean peak velocity for the common carotid artery. Five and 10 mg of 200- or 300-μm-diameter microspheres were injected into the ICA to evaluate the capture efficiency of the devices. The normalized pressure gradient, flow rate, and vascular resistance in the ICA were calculated from measured values of pressure and flow rate. Results The Spider RX captured the most particles (99.9% for 5 mg, 98.4% for 10 mg) and was associated with the slightest increase in pressure gradient (+8%, +15%) for both masses of microspheres injected. The Spider RX and FilterWire EZ were associated with the slightest decreases in flow rate (Spider RX, −1.9% and −12.1%; FilterWire EZ, −3.5% and −8.2%) and the slightest increases in vascular resistance (Spider RX, +10.1% and +33.0%; FilterWire EZ, +20.5% and +32.7%). The device-specific porosity was calculated, and the Spider RX was found to have the greatest at 50.4%; the Emboshield had the lowest at 2.2%. Conclusions The Spider RX and FilterWire EZ had the best overall performances. Design features such as porosity and pore density are important parameters for improving the effectiveness of EPFs. Vascular resistance in the ICA is a flow-derived variable indicative of device performance and affected by the filter design features.

The assumptions upon which the decisions to treat asymptomatic patients are founded on landmark studies, such as the Asymptomatic Carotid Atherosclerotic Study (ACAS), the Veterans Affairs Cooperative Study (VA), and the Asymptomatic Carotid Surgical Trial (ACST). In total, these trials randomized more than 5,000 patients to surgical vs. medical therapy. These trials were based on 60% stenosis and basically "no-risk" entry criteria. The carotid stent trials and registries, however, were based on 80% stenosis and all high-risk entry criteria. With a wide range of operator experience, and patient enrollment based on surgical risk criteria, Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Rare Events II (CAPTURE) II, Emboshield and Xact Post Approval Carotid Stent Trial (EXACT), and the Carotid Artery Revascularization Using the Boston Scientific EPI FilterWire EX/EZ and the EndoTex NexStent (CABERNET) trials were able to meet the American Heart Association guidelines of 3% procedural events in the asymptomatic subset. Carotid stenting is presently in the first and second generation of devices, and as the technology improves, procedural event rates should also improve. An understanding of the plaque composition and presence or absence of plaque vulnerability will separate those patients best suited for stenting versus endarterectomy. Asymptomatic patients cannot be grouped, but rather require individualization. Those patients with anatomical risks, preocclusive stenosis, and an incomplete Circle of Willis with a poorly collateralized hemisphere, are best managed with stenting versus endarterectomy or best medical management. Those patients, however, with

Purpose To assess the wall apposition of 3 distal protection filters used in carotid artery stenting (CAS) for cerebral protection and quantify the effect on the in vitro capture efficiency of the filters under simulated physiological flow conditions. Methods The 3 distal protection filters (Angioguard XP, FilterWire EZ, and RX Accunet) were deployed in silicone flow models of 5.0-, 5.5-, and 6.0-mm inner diameter and were tested at a mean flow rate characteristic of the human internal carotid artery while injecting polydispersed microspheres simulating plaque emboli. The injected microspheres had a diameter larger than the pore size of the devices tested, so it was conjectured that any microspheres missed by the device traveled between the device basket and the vessel wall. Varying the diameter of the vessel phantom within the recommended vessel diameter treatment range for each device simulated the variability of vessel diameter in vivo, allowing the quantification of device wall apposition. Results None of the devices tested completely prevented distal embolization in the flow model. The RX Accunet device has the best overall wall apposition, yielding gaps of 0.075% of the vessel cross-sectional area. The FilterWire EZ device had the best overall average filtration rate, failing to capture only 0.8% of plaque particles. There were no statistically significant differences in the wall apposition assessment or the capture efficiency of the RX Accunet and FilterWire EZ devices. Conclusion Several complications related to apposition of the filter basket on the vessel wall and device retrieval were detected in all the devices. It is inferred that the adaptability of the filter basket to conform to the vessel cross section at the site of deployment is the primary design variable responsible for distal embolization during CAS with cerebral protection.

Objectives: The multicenter, single-arm BEACH (Boston Scientific EPI: A Carotid Stenting Trial for High-Risk Surgical Patients) evaluated outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EX/EZ Emboli Protection System (Boston Scientific, Natick, Massachusetts). Background: Carotid artery stent (CAS) placement offers a less invasive alternative for high-risk surgical carotid endarterectomy (CEA) patients. Methods: The trial enrolled 480 pivotal patients who were candidates for carotid revascularization but considered high surgical risk due to pre-specified anatomic criteria and/or medical comorbidities. The primary end point (all stroke, death, or Q-wave myocardial infarction [MI] through 30 days; non-Q-wave MI through 24 h; and ipsilateral stroke or neurologic death through 1 year) was compared with a proportionally weighted objective performance criterion (OPC) of 12.6% for published surgical endarterectomy results in similar patients, plus a pre-specified noninferiority margin of 4%. Results: Among pivotal patients, 41.2% were at high surgical risk due to comorbid risk factors, and 58.8% due to anatomic risk factors; 76.7% were asymptomatic with flow-limiting carotid stenosis >80%. At 1 year, the composite primary end point occurred in 8.9% (40 of 447), with a repeat revascularization rate of 4.7%. With an upper 95% confidence limit of 11.5% for the primary composite end point, the BEACH trial results met the pre-specified criteria for noninferiority relative to the calculated OPC plus noninferiority margin (16.6%) for historical surgical CEA outcomes in similar patients (p < 0.0001 for noninferiority). Conclusions: The BEACH trial results demonstrate that CAS with the WALLSTENT plus FilterWire embolic protection is non-inferior (equivalent or better than) to CEA at 1-year in high-surgical-risk patients (Boston Scientific Embolic Protection, Inc. [EPI]: A Carotid Stenting Trial for High-Risk Surgical Patients [BEACH]; http://clinicaltrials.gov/ct2/show/NCT00316108?term=NCT00316108r NCT00316108).

Background: Pivotal study data examining carotid stenting with embolic protection as a less invasive alternative to endarterectomy for high surgical risk patients have been acquired under controlled conditions with highly selected physicians and hospitals. This report examines outcomes of carotid stenting post-approval after diffusion of this technology to a broader cross-section of physicians and hospitals. Methods: The Carotid Acculink/Accunet Post-Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) is a prospective, multi-center registry to assess two important aspects of the post-IDE experience: the safety of carotid stenting by physicians with varying levels of experience as a measure of the adequacy of physician training, and the identification of rare/unexpected device-related complications. The primary endpoint was a composite of death, any stroke, or myocardial infarction within 30 days post-procedure. Results: 3,500 patients were enrolled by 353 physicians at 144 sites. The 30-day primary endpoint event rate was 6.3% (95% CI: 5.5–7.1%) and did not differ among the three operator experience levels (5.3%, 6.0%, and 7.4%; P = 0.31) from most to least experienced, respectively. There were no differences in outcomes among physician specialties when adjusted for case mix. There were no unanticipated device related adverse events. Conclusions: The results of the CAPTURE study compare favorably to those achieved in the predicate pivotal investigations, and suggest that the post-approval transfer of this new therapy to the community practice setting via carotid stent training programs is effective in preparing physicians with varying experience levels and specialty training backgrounds. © 2006 Wiley-Liss, Inc.

Background: The use of carotid artery stenting with embolic protection has been practiced for over a decade in the United States, and increasingly so since carotid stenting received FDA approval in 2004. While there have been attempts at establishing predictors of outcomes in carotid artery stenting, they have generally been limited to single center experiences and/or multicenter retrospective surveys. This report examines predictors of outcomes in carotid stenting in the earliest and largest prospective multicenter neurologist-adjudicated experience in the United States post device approval. Methods: The Carotid Acculink®/Accunet® Post-Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) is a prospective, multi-center registry conducted to assess outcomes of carotid artery stenting (CAS) in the noninvestigational setting following device approval for high surgical risk patients (symptomatic with ≥50% stenosis; asymptomatic ≥80% stenosis). A neurologist examined the patients before the procedure, at 24 hr and 30-days post-procedure. The primary endpoint was a composite of death, any stroke, or myocardial infarction within 30-days post-procedure. Strokes and neurological events suspected to be strokes were adjudicated by an independent Clinical Events Adjudication Committee (CEAC) using prespecified definitions. Logistic regression analysis was performed to determine clinical, procedural, and anatomic predictors of endpoint outcomes. Results: Three thousand five hundred patients were enrolled at 144 sites by 353 physicians of varying specialty backgrounds and CAS experience. The 30-day primary endpoint event rate of death, stroke and MI was 6.3% [95% CI: 5.5–7.1%], and the rate of major stroke and death 2.9% [95% CI: 2.4–3.5]. Predictors of adverse outcomes included age, symptomatic patients, predilation prior to embolic protection device placement, time from symptoms to CAS procedure, and the use of multiple stents. Conclusions: In general, carotid stenting is performed safely in patients with severe stenosis at high surgical risk, with best outcomes in younger asymptomatic patients. However, there are certain patient and procedural characteristics that are associated with poorer outcomes. In these patients, the risk of stenting should be considered vis-a-vis both the anticipated benefit as well as the alternative surgical and medical options. © 2007 Wiley-Liss, Inc.

Stent fracture has been an uncommonly described etiology in the development of acute peripheral ischemia. We describe the utilization of a rheolytic thrombectomy catheter with thrombolytics for the rapid treatment of superficial femoral artery thrombosis after recanalization and subsequent stent fracture. The implications of stent fracture and the therapeutic maneuvers associated with their treatment in peripheral applications are discussed. © 2007 Wiley-Liss, Inc.

Objectives The aim of this study was to establish a consensus on Fundamental Endovascular Skills (FES) for educational purposes and development of training curricula for endovascular procedures. The term “Fundamental Endovascular Skills” is widely used; however, the current literature does not explicitly describe what skills are included in this concept. Endovascular interventions are performed by several specialties that may have opposing perspectives on these skills. Methods A two round Delphi questionnaire approach was used. Experts from interventional cardiology, interventional radiology, and vascular surgery from the United States and Europe were invited to participate. An electronic questionnaire was generated by endovascular therapists with an appropriate educational background but who would not participate in subsequent rounds. The questionnaire consisted of 50 statements describing knowledge, technical, and behavioral skills during endovascular procedures. Experts received the questionnaires by email. They were asked to rate the importance of each skill on a Likert scale from 1 to 5. A statement was considered fundamental when more than 90% of the experts rated it 4 or 5 out of 5. Results Twenty-three of 53 experts invited agreed to participate: six interventional radiologists (2 USA, 4 Europe), 10 vascular surgeons (4 USA, 6 Europe), and seven interventional cardiologists (4 USA, 3 Europe). There was a 100% response rate in the first round and 87% in the second round. Results showed excellent consensus among responders (Cronbach's alpha = .95 first round; .93 second round). Ninety percent of all proposed skills were considered fundamental. The most critical skills were determined. Conclusions A transatlantic multispecialty consensus was achieved about the content of “FES” among interventional radiologists, interventional cardiologists, and vascular surgeons from Europe and the United States. These results can serve as directive principles for developing endovascular training curricula.

With few exceptions, most of the occlusive disease involvingthegreatvesselsofftheaorticarchisnolonger considered a surgical disease. For example, both the right and the left subclavian arteries, the left common carotid origin, the innominate origin, and the proximal divisions of the right and left vertebral arteries are all quite amenable to endovascular stenting. There are however exceptions and these mayoccurwheneitheraneurysmaldisease,sepsis,trauma,or total occlusions that may not be amendable to recanalization by endovascular techniques are present. The causes of stenotic lesions in these vessels are similar to other vessels, where the majority is caused by atherosclerotic disease, although other causes such as dissection, fibromuscular disease (FMD), and various vasculitidies are not infrequent. The majority of the supraaortic atherosclerotic occlusive lesions involves the left subclavian artery. 1 Such disease resultsina“subclaviansteal,”whichwasfirstdescribedin1961 by Reivich and coworkers. 2,3 By occluding the left subclavian artery, arterial flow is provided by the right subclavian artery with flow into the right vertebral artery and then retrograde flow into the left vertebral artery and subsequently into left subclavian artery. Additional collaterals also include the external carotid, the ascending cervical artery, and the thyrocervical trunk.

background Carotid endarterectomy is more effective than medical management in the prevention of stroke in patients with severe symptomatic or asymptomatic atherosclerotic carotidartery stenosis. Stenting with the use of an emboli-protection device is a less invasive revascularization strategy than endarterectomy in carotid-artery disease. methods We conducted a randomized trial comparing carotid-artery stenting with the use of an emboli-protection device to endarterectomy in 334 patients with coexisting conditions that potentially increased the risk posed by endarterectomy and who had either a symptomatic carotid-artery stenosis of at least 50 percent of the luminal diameter or an asymptomatic stenosis of at least 80 percent. The primary end point of the study was the cumulative incidence of a major cardiovascular event at 1 year — a composite of death, stroke, or myocardial infarction within 30 days after the intervention or death or ipsilateral stroke between 31 days and 1 year. The study was designed to test the hypothesis that the less invasive strategy, stenting, was not inferior to endarterectomy. results The primary end point occurred in 20 patients randomly assigned to undergo carotidartery stenting with an emboli-protection device (cumulative incidence, 12.2 percent) and in 32 patients randomly assigned to undergo endarterectomy (cumulative incidence, 20.1 percent; absolute difference, i7.9 percentage points; 95 percent confidence interval, i16.4 to 0.7 percentage points; P=0.004 for noninferiority, and P=0.053 for superiority). At one year, carotid revascularization was repeated in fewer patients who had received stents than in those who had undergone endarterectomy (cumulative incidence, 0.6 percent vs. 4.3 percent; P=0.04). conclusions Among patients with severe carotid-artery stenosis and coexisting conditions, carotid stenting with the use of an emboli-protection device is not inferior to carotid endarterectomy.

Purpose: To compare the rates of neurological complications and restenosis for balloon-mounted (BM) versus self-expanding (SE) stents deployed in the extracranial carotid arteries. Methods: Among 513 patients (312 men; mean age 71.3 years, range 27–91) who underwent carotid artery stent placement, 496 received 520 stents. The patients were followed with periodic duplex ultrasound examinations; angiography was performed whenever the duplex scan identified a >50% stenosis or symptoms warranted investigation. Periproce-dural data on complications were analyzed on an intention-to-treat basis, while intermediate-term neurological complications were compared in stented patients. Results: In the periprocedural period, there were 19 (3.7%) transient ischemic attacks, 10 (1.9%) minor strokes, 6 (1.2%) major strokes, and 8 (1.6%) deaths among the 513 patients. Five (1.0%) of the deaths were related to neurological complications (3.9% all stroke/neurological death rate). Among the 496 patients receiving 247 (48%) BM stents and 273 (52%) SE stents in 518 arteries, the all stroke/neurological death rates were 3.6% and 4.0%, respectively (p>0.05). During a mean follow-up of 20.6 months (range to 5.6 years), the 3-year freedom from all fatal and ipsilateral nonfatal strokes excluding the 30-day periprocedural period was 95.0% for BM stents and 95.2% for SE devices. Vessel patency (>50%) at 3 years was 92.0% in the population: 96.3% for BM stents and 83.7% for SE stents (p=0.0422). Conclusions: The rate of neurological complications following carotid stenting has been relatively low overall, and no differences were found relative to the type of stent deployed. Vessel patency was excellent at 3 years, with slightly better patency in BM stents, but because of their vulnerability to compression, they will not replace SE stents.

Renal denervation through catheter-based ablation of renal nerves appears to be a promising therapy to treat resistant hypertension. Currently, there are several approaches in development to achieve ablation. These include energy-based approaches using radiofrequency (RF), ultrasound (intravascular and extra-vascular), beta-radiation and cryoablation [1–8]. All energy-based approaches are untargeted and have the potential to damage the vascular wall and surrounding tissue. Moreover, OCT findings have shown that RF probes damage the endothelial layer and cause thrombus formation on the intraluminal side [9]. Late stenosis in renal arteries have also been reported in a limited number of cases with RF ablation [10, 11]. In addition, energy-based approaches are not suitable for treating stented areas of the renal arteries [12].

Purpose: To review the neurological complications associated with extracranial carotid artery stenting and to preliminarily assess techniques used to manage these complications. Methods: Between April 1994 and August 2000, 450 patients (270 men; mean age 70.2 years, range 27–89) had stents implanted to treat 472 cervical carotid artery stenoses. Over half (257, 57%) of the patients were symptomatic. A variety of stents were implanted percutaneously after predilation of the lesion; a third of the patients received glycoprotein IIb/IIIa inhibitors intraprocedurally in addition to a standard oral antiplatelet regimen (aspirin and ticlopidine or clopidogrel). Occurrence and management of neurological complications within the 30-day periprocedural period were reviewed. Results: There were 14 (3.1%) transient ischemic attacks (TIAs), 10 (2.2%) minor strokes, and 3 (0.7%) major strokes. Among 6 (1.3%) procedure-related deaths, 4 had neurological causes. The total stroke and death rate was 4.2% (n =19). All the TIAs, 4 of which occurred between 1 and 14 days poststenting, were treated medically, as were the minor strokes, 3 of which occurred >24 hours after stenting. Only 2 minor stroke patients had mild residual upper extremity motor deficits. Intra-arterial thrombolytic therapy was administered in 5 cases (2 major strokes survivors and 3 patients who suffered a neurologically-related death); occlusions were identified in the proximal middle cerebral artery (MCA) in 3 and the distal MCA in 2. Angiographic improvement was noted in 4 (80%), but only the 2 (40%) with distal MCA occlusions did well clinically. Conclusions: Neurological complications following carotid artery stenting are inevitable. The occurrence of minor strokes >24 hours following stenting may indicate a possible late embolic phenomenon, which warrants investigation. Likewise, the marginal efficacy of intra-arterial thrombolytic therapy demonstrates an inability to lyse embolic plaque and underscores the need for effective distal protection.

Objective: Carotid bifurcation angioplasty and stenting (CBAS) has generated controversy and widely divergent opinions about its current therapeutic role. To resolve differences and establish a unified view of CBAS' present role, a consensus conference of 17 experts, world opinion leaders from five countries, was held on November 21, 1999. Methods: These 17 participants had previously answered 18 key questions on current CBAS issues. At the conference these 18 questions and participants' answers were discussed and in some cases modified to determine points of agreement (consensus), near consensus, (prevailing opinion), or divided opinion (disagreement). Results: Conference discussion added two modified questions, placing a total of 20 key questions before the participants, representing four specialties (interventional radiology, seven; vascular surgery, six; interventional cardiology, three; neurosurgery, one). It is interesting that consensus was reached on the answers to 11 (55%) of 20 of the questions, and near consensus was reached on answers to 6 (30%) of 20 of the questions. Only with the answers to three (15%) of the questions was there persisting controversy. Moreover, both these differences and areas of agreement crossed specialty lines. Consensus Conclusions: CBAS should not currently undergo widespread practice, which should await results of randomized trials. CBAS is currently appropriate treatment for patients at high risk in experienced centers. CBAS is not generally appropriate for patients at low risk. Neurorescue skills should be available if CBAS is performed. When cerebral protection devices are available, they should be used for CBAS. Adequate stents and technology for performing CBAS currently exist. There were divergent opinions regarding the proportions of patients presently acceptable for CBAS treatment (

Purpose: To present the results of a multicenter registry established to collect data on carotid stent procedures in patients with restenosis following carotid endarterectomy. Methods: The procedural details, outcomes, and late follow-up results were collected from 14 centers in the United States. Thirty-day and late stroke and death rates were analyzed. Results: Three hundred and thirty-eight patients (201 men; 71 ± 8 years) underwent carotid stenting in 358 arteries. The average duration from carotid endarterectomy was 5.5 ± 7.3 years. Sixty-one percent of the patients were asymptomatic. The overall 30-day stroke and death rate was 3.7%. The minor stroke rate was 1.7% (6/358), and the major nonfatal stroke rate was 0.8% (3/358). The fatal stroke rate was 0.3% (1/358), and the nonstroke-related death rate was 0.9% (3/338). There was 1 (0.3%) fatal and 1 (0.3%) nonfatal stroke during the follow-up period. The overall 3-year rate of freedom from all fatal and nonfatal strokes was 96% ± 1% (±SE). Conclusions: Carotid artery stenting can be performed in patients with restenosis following carotid endarterectomy with 30-day complication rates comparable to those of most published studies on repeat carotid endarterectomy. Results of late follow-up suggest that this technique is durable and efficacious.

Percutaneous revascularization techniques have dramatically altered traditional approaches to the management of both coronary and peripheral vascular disease. Their major advantage is that they are less invasive than conventional surgical procedures, offering revascularization without the risk of general anesthesia and with lesser procedural morbidity and mortality, shorter hospital stay, and lower cost. In patients with comorbidities that increase their risk of surgical complications, percutaneous revascularization techniques are the procedures of choice. The Achilles heel of balloon angioplasty, the higher risk of lesion recurrence, restenosis, has been markedly reduced with the use of endovascular stents. Over the past 20 years, percutaneous angioplasty and stenting have become accepted alternatives to surgical revascularization of aortoiliac, renal, femoropopliteal, subclavian, brachiocephalic, and dialysis access lesions. The most recent application of percutaneous intervention has been to explore its clinical utility and safety for stroke prevention in stenotic extracranial carotid arteries.

The management of high-grade stenosis involving the petrosal segment of the internal carotid artery has been limited to angioplasty alone in the past. However, if angioplasty fails or has less than optimum results, then endovascular stent placement should be considered. We present the first two known cases in which the Multi-Link coronary stent was used for the treatment of internal carotid disease in the petrosal segment. The first patient had symptomatic stenosis that failed angioplasty after seven months and the second patient had a symptomatic lesion that dissected upon angioplasty. The flexibility and low profile characteristics of the stent allowed it to be safely deployed with balloon expansion. No complications occurred and the patients tolerated the procedure. Patients were carefully monitored and no new neurologic events in six months of follow up occurred. These cases reveal the good clinical results of stent placement for surgically-inaccessible lesions of the internal carotid artery in the skull base.

Our purpose was to study the effectiveness of thrombolytic therapy in treating acute, subacute, and chronic arterial occlusions in a multicenter retrospective study. Intraarterial urokinase infusion was performed in 235 patients for occluded native arteries. There were 70 (30%) with acute and 26 (5%) with subacute occlusions, and 141 (59%) with chronic symptoms for longer than 3 mo. Complete thrombolysis was achieved in 60 (86%) of the acute, 20 (77%) of the subacute, and 106 (75%) of the chronic occlusions. Adjunctive interventional procedures were performed as needed. Long-term follow-up revealed a primary patency of 87%, 85%, and 76% for the acute, subacute, and chronic occlusion groups, respectively. We conclude that the rate of complete thrombolysis of chronic occlusions proved slightly more efficient for acute and virtually the same for subacute occlusions. Long-term follow-up demonstrated a higher failure rate with chronic than with acute occlusions, probably due to worsened peripheral vascular runoff. Cathet. Cardiovasc. Diagn. 44:159–169, 1998. © 1998 Wiley-Liss, Inc.

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development. Cathet. Cardiovasc. Diagn. 44:1–6, 1998. ©1998 Wiley-Liss, Inc.

Ectopic kidneys are rare and usually present incidental findings during invasive or non-invasive angiography. Their parenchyma is not more susceptible to disease and symptoms occur mainly due to alteration of the anatomic relations. The main renal artery of the ectopic kidney derives invariably from the aorta; however, accessory renal arteries may originate from almost any arterial branch adjacent to the ectopic kidney. Knowledge of the common anatomic variations is important during complex peripheral interventions. We present the case of a 46-year-old male with symptoms of claudication secondary to left common iliac artery occlusion. He was diagnosed as occlusion of the left common iliac artery at the aortoiliac bifurcation in close proximity to the ectopic renal artery by peripheral angiography, and percutaneous intervention of the left common iliac artery was successful. Percutaneous intervention led to resolution of the patient's symptoms of claudication as well as preservation of the ectopic renal artery. In such cases, renal ectopy and aberrant arteries should be promptly recognized in order to avoid vascular or renal complications.

A feasibility study of stent supported angioplasty for the extracranial occlusive disease was conducted to include the carotid bifurcation and the internal carotid artery. One hundred seventy-four patients have undergone extra-cranial PTA and/or Meriting for occlusive disease involving the great vessels off the aortic arch, including the internal carotid. Sixty-one of the patients represented carotid occlusive disease, of which 15 were managed by PTA and 46 by intravascular Johnson & Johnson Interventional Systems stents. There were 13 vertebrals in the group, 7 innominate, 81 subclavian, 10 axillary lesions, and 2 grafts, I of which was an internal carotid interposi-tioned vein graft. The 61 patients that had carotid angioplasty and/or stents had a complication rate of 8%. However, 46 patients had a primary stenting procedure. From this group, 2 patients had minor strokes involving the upper extremities. One patient recovered fully within 24 hours, and the other had an 85% recovery at the end of a 1-week interval. Two patients encountered transient ischemic attacks. There were no deaths, and no major disabling strokes in the carotid series. The follow-up for the carotid stem group had a mean duration of only 2.5 months. Twenty-nine of the patients have been reevaluated with no new onset of neurological sequelae. There were no stent deformations noted as evaluated by three-dimensional computed tomographic angiography and color flow Doppler in addition to magnificant radiography. All patients have had 24-hour postoperative and 1-month color flow Doppler. All patients are required by protocol to undergo angiographic evaluation. If we include all extracranial interventions (174), a technical success of 93% was achieved in those patients undergoing PTA and 94% of those patients undergoing stenting procedures. Suboptitnal results were obtained in 6% of the PTA procedures, and 0% for stents. There is now sufficient data to document the efficacy of managing extracranial occlusive disease by percutaneous endovascutar stents. The exception, however, is the carotid bifurcation and the internal carotid artery, where a well-controlled feasibility study with careful analysis of the data will be necessary prior to randomizing the study against the gold standard of carotid endarterectomy.

Most physicians, and certainly the lay public, have only limited knowledge of the responsibilities and limits of the Food and Drug Administration (FDA) of the United States of America. Although laws as early as 1902 protected the public from unrestricted sale of unsafe drugs, it was not until 1976 that devices came under regulation. An obvious difference existed between regulatory control of drugs vs devices. The drug-based approach for evaluation was rejected in favor of a new system based on device class and its degrees of risk. The premarket notification process (510K), and the premarket approval application (PMAA) became the regulatory pathway for device approval. The investigational device exemption (IDE) became the mechanism for established safety and efficacy. Occasionally conflicts exist between industry and the FDA. Submission of poorly planned studies wastes FDA resources whereas prolonged approval times can be devastating to the small single product business that creates the majority of our new devices. A compromise is obviously necessary if we are to maintain our premier identity as a new device entrepreneurial center and avoid industry's migration to countries where the regulatory standards might be less rigid.

Carotid artery related stroke is mainly an embolic disease that has been associated with inflammation, plaque rupture, and thrombus formation in “vulnerable” atherosclerotic plaque. Almost, two-thirds of these strokes affect patients who are previously asymptomatic. Estimation of the degree of

Plaque composition is a potentially important diagnostic feature for carotid artery stenting (CAS). The purpose of this investigation is to evaluate the reproducibility of manual border correction in intravascular ultrasound with virtual histology (VH IVUS) images. Three images each were obtained from 51 CAS datasets on which automatic border detection was corrected manually by two trained observers. Plaque was classified using the definitions from the CAPITAL (Carotid Artery Plaque Virtual Histology Evaluation) study, listed in order from least to most pathological: no plaque, pathological intimal thickening, fibroatheroma, fibrocalcific, calcified fibroatheroma, thin-cap fibroatheroma, and calcified thin-cap fibroatheroma. Inter-observer variability was quantified using both weighted and unweighted Kappa statistics. Bland-Altman analysis was used to compare the cross-sectional areas of the vessel and lumen. Agreement using necrotic core percentage as the criterion was evaluated using the unweighted Kappa statistic. Agreement between classifications of plaque type was evaluated using the weighted Kappa statistic. There was substantial agreement between the observers based on necrotic core percentage (κ = 0.63), while the agreement was moderate (κquadratic = 0.60) based on plaque classification. Due to the time-consuming nature of manual border detection, an improved automatic border detection algorithm is necessary for using VH IVUS as a diagnostic tool for assessing the suitability of patients with carotid artery occlusive disease for CAS.

ObjectivePatient and device selection are important for the success of carotid artery stenting (CAS). We hypothesize that distal protection filter (DPF) design characteristics that minimize blood flow resistance and maximize capture efficiency are associated with the absence of transient ischemic attack (TIA), stroke and neurologic-related death after 30 days.MethodsRecords from 208 patients were reviewed retrospectively. Filter design characteristics were quantified previously in our laboratory. The association between risk factors and design characteristics with 30-day outcome was quantified using univariate analysis.ResultsThe 30-day all-cause stroke and death rate was 8.7% (asymptomatic: 7.7%, symptomatic: 10.6%). Five DPFs were used in the study: Accunet (41.3%), Angioguard (33.2%), FilterWire (24%), Emboshield (1%), and Spider (.5%). Diabetes (P = .04) and prior carotid endarterectomy (CEA, P = .03) were associated with adverse outcome. Prior stroke (P = .01) and prior CEA (P = .04) were significant for peri-procedural stroke. Design characteristics such as capture efficiency were associated with favorable outcomes.ConclusionsPatients with prior CEA or stroke are more likely to have unfavorable CAS outcomes after 30 days. Filters with high capture efficiency may yield the best clinical results. Analysis of the effect of design characteristics on CAS outcome should aid the design of future devices.

Objectives: To evaluate the cost-effectiveness of carotid stenting vs. carotid endarterectomy using data from the SAPPHIRE trial. Background: Carotid stenting with embolic protection has been introduced as an alternative to carotid endarterectomy for prevention of cerebrovascular and cardiovascular events among patients at increased surgical risk. Methods: Between August 2000 and July 2002, 310 patients with an accepted indication for carotid endarterectomy but at high risk of complications were randomized to and subsequently underwent either carotid stenting (n = 159) or endarterectomy (n = 151). Clinical outcomes, resource use, costs, and quality of life were assessed prospectively for all patients over a 1-year period. Life expectancy, quality-adjusted life expectancy, and health care costs beyond the follow-up period were estimated for patients alive at 1 year, based on observed clinical events during the first year of follow-up. Results: Although initial procedural costs were significantly higher for stenting than for endarterectomy (mean difference: $4,081/patient; 95% CI, $3,849–$4,355), mean post-procedure length of stay was shorter for stenting (1.9 vs. 2.9 days; P < 0.001) with significant associated cost offsets. As a result, initial hospital costs were just $559/patient higher with stenting (95% CI, $3,470 less to $2,289 more). Neither follow-up costs after discharge nor total 1-year costs differed significantly. The incremental cost-effectiveness ratio for stenting compared with endarterectomy was $6,555 per quality-adjusted life year (QALY) gained, with over 98 percent of bootstrap estimates

The majority (80%) of the three-quarters of a million strokes that will occur in the United States this year are ischemic in nature. The treatment of acute ischemic stroke is very similar to acute myocardial infarction, which requires timely reperfusion therapy for optimal results. The majority of patients with acute ischemic stroke do not receive any form of reperfusion therapy, unlike patients with acute myocardial infarction. Improving outcomes for acute stroke will require patient education to encourage early presentation, an aggressive expansion of qualified hospitals, and willing providers and early imaging strategies to match patients with their best options for reperfusion therapy to minimize complications.

Palmaz balloon-expandable intraluminal stents (BEISs) were used to treat vena caval and adjacent central venous obstructions that failed to respond to conventional balloon angioplasty. An initial series included seven patients: five had superior vena cava (SVC) syndrome due to a malignant neoplasm and/or radiation therapy, one had dialysis access-related stenosis of the subclavian vein, and one had inferior vena cava (IVC) and bilateral common iliac vein obstruction due to abdominopelvic radiation therapy for Hodgkin disease. Treatment produced clinical benefit in all seven patients. Patency was achieved with stents placed across stenoses of the SVC, IVC, and brachiocephalic and subclavian veins. One stent placed in a left common iliac vein was oval and was shown to be occluded on a follow-up computed tomographic scan, suggesting that compression between the right common iliac artery and the spine was responsible. Although caution is recommended in placement at possible compression sites, BEISs can be used to treat obstructions of the vena cava and major central veins.

Purpose: To assess in vitro the performance of 5 distal protection devices (DPDs) by evaluating the capture efficiency, pressure gradient, volume flow rate, and vascular resistance in the internal carotid artery (ICA). Methods: The time-averaged mean peak velocity in the common carotid artery and a blood-mimicking solution were used to simulate physiological conditions in a silicone carotid phantom representing average human carotid artery geometry with a 70% symmetrical ICA stenosis. Five milligrams of dyed 200-μm nominal diameter polymer microspheres (larger than the pore size of the devices, except Spider RX, which was tested with 300-μm-diameter particles) were injected into the ICA. The percentages of particles missed after injection and lost during device retrieval were measured for the 5 devices (Spider RX, FilterWire EZ, RX Accunet, Angioguard XP, and Emboshield). The normalized pressure gradient, fraction of the volume flow rate, and vascular resistance in the ICA were calculated. Results: Spider RX captured the most particles (missing 0.06%, p−1, a 5.4% increase with respect to initial conditions). Angioguard XP captured the fewest particles (missing 36.3%, p−1, an 82.2% increase). Emboshield migrated ∼6 cm distal to the original position after particle injection. FilterWire EZ lost the fewest particles during retrieval (0.45%, pConclusion: None of the devices tested completely prevented embolization. Overall, Spider RX had the best performance and is conjectured to have the best wall apposition of the devices tested. Vascular resistance should be considered a key filter design parameter for performance testing since it represents a quantitative estimation of the “slow-flow phenomenon.” Our findings should be extrapolated cautiously to help interventionists choose the best device.

Although previous reports of carotid stenting with embolic protection (CAS) have focused on clinical outcomes of death, stroke and myocardial infarction, there are few data available characterizing the strokes that occur during CAS, thus limiting understanding of potential mechanisms. This report examines the timing, location, severity, and type of strokes occurring with CAS in the Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) study.The CAPTURE is a prospective, multicenter registry conducted to assess outcomes of CAS in the postapproval setting after device approval. A neurologist examined the patients before the procedure, at 24 hours and 30 days post-procedure. The primary end point was a composite of death, any stroke, or myocardial infarction within 30 days post-procedure. Strokes and all neurologic events suspected to be strokes were adjudicated by an independent Clinical Events Adjudication Committee using prespecified definitions. Source documents of all patients with strokes in this cohort were reviewed.The 30-day results were available for 3500 patients. The 30-day primary end point event rate of death, stroke, and myocardial infarction was 6.3% (95% confidence interval: 5.5%-7.1%), and the rate of major stroke and death was 2.9% (95% confidence interval: 2.4 to 3.5). 4.8% of patients experienced a stroke (3.9% ipsilateral and 0.9% nonipsilateral, 2% major). A majority of stroke symptoms (57.7%) were noted post-procedure and pre-discharge, whereas 22.3% were noted during the procedure and 20% postdischarge. A similar timing distribution regardless of preprocedural symptomatic status was found.Overall, 41% (69 of 170) of all strokes were major. The incidence of major strokes was statistically significantly greater among symptomatic compared with asymptomatic patients, 4.6% (22 of 482) and 1.6% (47 of 3018), respectively. There were more minor than major strokes in asymptomatic patients (63% vs. 37%; P=0.10), whereas stroke severity was equally distributed in symptomatic patients. Among the ipsilateral strokes, almost half (44%) were major, whereas only one-quarter (26%) of the nonipsilateral strokes were major.Overall, 23% of the major strokes were hemorrhagic and 94% of these strokes were noted on the ipsilateral side. There was a tendency toward more major hemorrhagic strokes in symptomatic than in asymptomatic patients (36% vs. 17%; P=0.07). Fifty-four percent of the strokes post-procedure and pre-discharge were major, whereas 27% of the strokes postdischarge were major. Furthermore, 65% of hemorrhagic strokes were noted post-procedure and pre-discharge, 30% postdischarge.Strokes related to CAS seem to become clinically apparent after the procedure but before discharge in the majority of events. Nevertheless, a significant minority of stroke symptoms follows discharge from the hospital, typically after 24 hours. Timing of stroke after CAS seems to be similar to timing of stroke after carotid endarterectomy. Moreover, nearly 1 in 5 strokes occur in a nonipsilateral distribution, with the exception of intraprocedural events, which were all ipsilateral to the stent being implanted. Hemorrhagic stroke seemed to be more prevalent in the strokes occurring in the post-procedure period. These descriptors of stroke severity, location, and timing may provide insight in to the mechanistic causes of adverse neurologic outcomes in CAS.