Double Filtration During Carotid Artery Stenting Using a Novel Post-Dilation Balloon With Integrated Embolic Protection

Transradial carotid artery stenting using double layer micromesh stent and novel post-dilation balloon with integrated embolic protection

OBJECTIVES

The highest rate of embolization during carotid artery stenting occurs during post-dilation. We evaluated the ability of the Paladin system (Contego Medical, Raleigh, NC), a novel PTA balloon with an integrated 40-ɥm pore filter, to collect microemboli that may pass into the cerebral circulation when used during post-dilation.

METHODS

25 symptomatic patients underwent transradial CAS using the Paladin system in conjunction with the Roadsaver (Terumo Corporation, Tokyo, Japan) micromesh stent. No additional embolic protection was used. The Paladin filters were collected following the procedure and preserved in formalin for histological analysis. The contents were evaluated for particle count and size. Subjects were followed for 30 days and evaluated for major cardiac adverse events (death, stroke and MI). Secondary endpoints included procedure success, device success, access site complications according to EASY score classification, major vascular or ischemic complications at follow up and in-stent restenosis rate evaluated with duplex ultrasound.

RESULTS

Mean age of patients was 68,5 years. Type 2 aortic arch was present in 77 % of patients and type 1 and type 3 in 12 % and 11 % of patients respectively. Procedural and device success was obtained in all cases without complications. The 30-day MAE rate was 0 %. Twenty-three filters underwent histological analysis. Microscopic debris was present in 100 % of filters, and 75 % of particles were less than 100ɥm in size. The mean number of particles per filter was 3352 ± 1567 (IQR 4300-2343), and the mean number of particles between 40-100ɥm per filter was 2499 ± 1240 (IQR 3227-1575).

CONCLUSION

CAS through radial approach can be safely and effectively performed using the IEP technology Paladin device and double-layer micromesh Roadsaver stent. This strategy can simplify the procedure and decrease peri-procedural complications and procedural time.

Carotid artery interventions - endarterectomy versus stenting

Current management of patients with carotid artery stenosis is based on well-established guidelines, including surgical procedures - carotid endarterectomy (CEA) and endovascular carotid artery stenting (CAS) - and optimal medical treatment alone. Outcomes in the postprocedural period after CAS and CEA are similar, suggesting strong clinical durability for both treatments. Recent advances, which include the emergence of novel endovascular treatment tools and techniques, combined with more recent randomised trial data shed new light on optimal patient selection and treatment in contemporary practice. Improved, modern technologies including enhanced embolic protection devices and dual-layered micromesh stents yield better outcomes and should result in further improvements in CAS. In centres of excellence, nowadays, the majority of patients with severe carotid artery stenosis can be successfully treated with either CEA or CAS.

Procedural embolic protection strategies for carotid artery stenting: current status and future prospects

INTRODUCTION

Carotid artery angioplasty and stenting (CAS) is an established procedure to treat carotid artery stenosis for either primary or secondary prevention of stroke. Randomized clinical trials have shown an increased risk of periprocedural cerebrovascular events with CAS compared with carotid endarterectomy (CEA). Several strategies have been proposed to mitigate this risk, including alternative vascular access site, proximal/distal embolic protection devices, and dual-layer stents, among others.

AREAS COVERED

This review provides a general overview of current embolic protection strategies for CAS. The phases of the procedure which can affect the early risk of stroke and how to reduce it with novel techniques and devices have been discussed.

EXPERT OPINION

Innovations in device technologies have dramatically improved the safety and efficacy of CAS. To minimize the gap with surgery, a thorough, patient-oriented approach should be pursued. Endovascular technologies and techniques should be selected on an individual basis to address unique lesion characteristics and vascular anatomies. Meticulous pre-procedural planning, both clinical and anatomical, is needed to assess the embolic risk of each procedure. Only by having an in-depth understanding of the wide range of available endovascular devices and techniques, the operator will choose the most appropriate strategy to optimize CAS results.

Proximal versus distal protection: dissecting clinical trials

Carotid artery stenting (CAS) is a valid alternative to conventional carotid endarterectomy for treatment of carotid artery stenosis. Distal embolization of atherosclerotic debris causing cerebrovascular accidents during CAS has been the most significant concern limiting widespread application of CAS technology. A variety of embolic protection devices (EPDs) with different mechanism of action, have been designed to minimize the risk of major embolization causing stroke and their use is recommended by current guidelines. Two general types of EPDs are available: proximal protection devices (PPDs) and distal protection devices (DPDs). However, there is no convincing clinical evidence of the clinical superiority of one device over another. This review will examine the different types of available devices and also innovative devices and techniques, including strengths and weaknesses of each, and present the available evidence and rationale for their routine use during CAS.

PERFORMANCE 1 study: Novel carotid stent system with integrated post-dilation balloon and embolic protection device

OBJECTIVES

The PERFORMANCE I study was designed to evaluate the safety and feasibility of the Neuroguard IEP® System, a novel carotid stent system with an integrated embolic filter and post-dilatation balloon, to treat clinically significant carotid artery stenosis.

BACKGROUND

The risk of major adverse events during carotid artery stenting is comparable to carotid endarterectomy, however, the risk of minor stroke remains higher with stenting.

METHODS

In total, 67 patients undergoing carotid artery stenting were enrolled at nine centers in Europe. Follow-up assessments included neurological exams, duplex ultrasound, 12-lead electrocardiogram, and cardiac enzyme analysis. The primary endpoint was the 30-day composite rate of stroke, death, and myocardial infarctions versus a prespecified performance goal. Secondary endpoints included procedure success, device success, and target lesion revascularization.

RESULTS

The study population was predominantly male (74.6%) with a mean age of 69.3 ± 8.9 years and 67% of subjects met at least one criterion placing them at an elevated risk for adverse events following carotid endarterectomy. All patients were treated successfully with the study device. There were no deaths or strokes within 30 days of the index procedure. One subject (1.5%) experienced a non-ST elevation myocardial infarction at day 17. The primary endpoint was met with a 30-day major adverse events rate of 1.5% (1/67). Through 12-month follow-up, there were no strokes, neurological deaths, target lesion revascularizations, or instances of in-stent-restenosis.

CONCLUSIONS

Results from this study demonstrate the Neuroguard IEP system is safe and feasible with a stroke/death rate of 0% at 30 days. A large pivotal study is currently underway.

Carotid endarterectomy or stenting or best medical treatment alone for moderate-to-severe asymptomatic carotid artery stenosis: 5-year results of a multicentre, randomised controlled trial

BACKGROUND

The optimal treatment for patients with asymptomatic carotid artery stenosis is under debate. Since best medical treatment (BMT) has improved over time, the benefit of carotid endarterectomy (CEA) or carotid artery stenting (CAS) is unclear. Randomised data comparing the effect of CEA and CAS versus BMT alone are absent. We aimed to directly compare CEA plus BMT with CAS plus BMT and both with BMT only.

METHODS

SPACE-2 was a multicentre, randomised, controlled trial at 36 study centres in Austria, Germany, and Switzerland. We enrolled participants aged 50-85 years with asymptomatic carotid artery stenosis at the distal common carotid artery or the extracranial internal carotid artery of at least 70%, according to European Carotid Surgery Trial criteria. Initially designed as a three-arm trial including one group for BMT alone (with a randomised allocation ratio of 2·9:2·9:1), the SPACE-2 study design was amended (due to slow recruitment) to become two substudies with two arms each comparing CEA plus BMT with BMT alone (SPACE-2a) and CAS plus BMT with BMT alone (SPACE-2b); in each case in a 1:1 randomisation. Participants and clinicians were not masked to allocation. The primary efficacy endpoint was the cumulative incidence of any stroke or death from any cause within 30 days or any ipsilateral ischaemic stroke within 5 years. The primary safety endpoint was any stroke or death from any cause within 30 days after CEA or CAS. The primary analysis was by intention-to treat, which included all randomly assigned patients in SPACE-2, SPACE-2a, and SPACE-2b, analysed using meta-analysis of individual patient data. We did two-step hierarchical testing to first show superiority of CEA and CAS to BMT alone then to assess non-inferiority of CAS to CEA. Originally, we planned to recruit 3640 patients; however, the study had to be stopped prematurely due to insufficient recruitment. This report presents the primary analysis at 5-year follow-up. This trial is registered with ISRCTN, number ISRCTN78592017.

FINDINGS

513 patients across SPACE-2, SPACE-2a, and SPACE-2b were recruited and surveyed between July 9, 2009, and Dec 12, 2019, of whom 203 (40%) were allocated to CEA plus BMT, 197 (38%) to CAS plus BMT, and 113 (22%) to BMT alone. Median follow-up was 59·9 months (IQR 46·6-60·0). The cumulative incidence of any stroke or death from any cause within 30 days or any ipsilateral ischaemic stroke within 5 years (primary efficacy endpoint) was 2·5% (95% CI 1·0-5·8) with CEA plus BMT, 4·4% (2·2-8·6) with CAS plus BMT, and 3·1% (1·0-9·4) with BMT alone. Cox proportional-hazard testing showed no difference in risk for the primary efficacy endpoint for CEA plus BMT versus BMT alone (hazard ratio [HR] 0·93, 95% CI 0·22-3·91; p=0·93) or for CAS plus BMT versus BMT alone (1·55, 0·41-5·85; p=0·52). Superiority of CEA or CAS to BMT was not shown, therefore non-inferiority testing was not done. In both the CEA group and the CAS group, five strokes and no deaths occurred in the 30-day period after the procedure. During the 5-year follow-up period, three ipsilateral strokes occurred in both the CAS plus BMT and BMT alone group, with none in the CEA plus BMT group.

INTERPRETATION

CEA plus BMT or CAS plus BMT were not found to be superior to BMT alone regarding risk of any stroke or death within 30 days or ipsilateral stroke during the 5-year observation period. Because of the small sample size, results should be interpreted with caution.

FUNDING

German Federal Ministry of Education and Research (BMBF) and German Research Foundation (DFG).

Thromboembolic complications in transfemoral aortic valve implantation due to aortic wall thrombus and shaggy aorta syndrome

OBJECTIVES

Aortic wall thrombus (AWT) can affect suitability to endovascular repair, while its most aggressive entity is better known as shaggy aorta syndrome. Primary objective was to study the procedural and clinical outcome with regard to atherothrombotic AWT in transfemoral aortic valve implantation.

METHODS

In a retrospective, single-centre analysis, a qualitative 0-10 AWT score classification system was used. The most severely affected aortic area in computed tomography angiography cross-section was assessed for the number of affected segments, thrombus type, thickness, area and circumference. Primary endpoints were 30-day mortality, neurologic, renal and pulmonary events and signs of solid organ infarction.

RESULTS

Between November 2017 and September 2019, 604 patients underwent transfemoral transcatheter aortic valve implantation in our institution. Computed tomography-guided analysis revealed AWT in 11.3% and shaggy aorta syndrome in 6 patients (1.0% with 83.3% male). AWT was mainly present in the descending thoracic and abdominal aorta and was associated with acute renal failure (11.8% vs 3.2%, P ≤ 0.001) and a seven-fold increased rate of disabling peri-interventional stroke (4.4% vs 0.6%, P ≤ 0.001). In all patients with disabling peri-interventional stroke a balloon-expandable prosthesis was used (P ≤ 0.001). In case of shaggy aorta, mortality was more than six-fold increased (2.8% vs 16.7%, P = 0.046).

CONCLUSIONS

Severe and irregular thrombus of the descending thoracic and abdominal aorta has been strongly associated with acute respiratory failure and peri-interventional stroke in transfemoral aortic valve implantation, being more likely using balloon-expandable devices. Our results imply important changes with regard to device design and present international transcatheter aortic valve implantation guidelines.

Quality Assurance for Carotid Stenting in the CREST-2 Registry

BACKGROUND

The CREST-2 Registry (C2R) was approved by National Institute of Neurological Disorders and Stroke-National Institutes of Health in September 2014 with Centers for Medicare & Medicaid Services, U.S. Food and Drug Administration, and industry collaboration to enroll patients undergoing CAS. The registry credentials interventionists and promotes optimal patient selection, procedural-technique, and outcomes.

OBJECTIVES

This study reports periprocedural outcomes in a cohort of carotid artery stenting (CAS) performed for asymptomatic and symptomatic carotid stenosis.

METHODS

Asymptomatic patients with ≥70% and symptomatic patients with ≥50% carotid stenosis, ≤80 years of age, and at standard or high risk for carotid endarterectomy are eligible for enrollment. Interventionists are credentialed by a multispecialty committee that reviews experience, lesion selection, technique, and outcomes. The primary endpoint was a composite of stroke and death (S/D) in the 30-day periprocedural period. Myocardial infarction and access-site complications were assessed as secondary outcomes.

RESULTS

As of December 2018, 187 interventionists from 98 sites in the United States performed 2,219 CAS procedures in 2,141 patients with primary atherosclerosis (78 were bilateral). The mean age of the cohort was 68 years, 65% were male, and 92% were white; 1,180 (55%) were for asymptomatic disease, and 961 (45%) were for symptomatic disease. All U.S. Food and Drug Administration-approved stents and embolic protection devices were represented. The 30-day rate of S/D was 1.4% for asymptomatic, 2.8% for symptomatic, and 2.0% for all patients.

CONCLUSIONS

C2R is the first national registry for CAS cosponsored by federal and industry partners. CAS was performed by experienced operators using appropriate patient selection and optimal technique. In that setting, a broad group of interventionists achieved very low periprocedural S/D rates for asymptomatic and symptomatic patients.

Prospective multicentre study of carotid artery stenting using the MER™ Stent - the OCEANUS study - 30-day and one-year follow-up results

INTRODUCTION

Constant technological progress in the field of carotid stenting translates into improved short- and long-term results of endovascular treatment. The introduction of a new generation, self-expanding, open-cell stent has provided a new treatment option in endovascular management of carotid stenosis.

AIM

To evaluate 30-day and 1-year clinical outcomes of non-consecutive patients with high risk of carotid endarterectomy, who underwent 5F cylinder-tapered MER™ open-cell carotid stent implantation.

MATERIAL AND METHODS

It was a single-arm, prospective study conducted in four experienced catheterisation centres. The use of embolic protection devices was mandatory. The primary endpoint was stroke in 30-day follow-up. The secondary endpoints were 30-day and 1-year cumulative incidence of death, stroke and myocardial infarction, 1-year target vessel revascularisation, procedural success (residual stenosis ≤ 30%), restenosis rate (%DS ≥ 50%), and Serious Adverse Device Effect (SADE) rate in 1-year follow-up.

RESULTS

In total 100 patients were recruited for the study, with the majority being males (n = 61). The mean age was 68.3 ±8.2 years, and most of the patients were asymptomatic (n = 56). In 55 (55%) patients direct stenting was performed, with the use of proximal protection devices in 19 (19%) patients. Mean internal carotid artery/common carotid artery stenosis before and after stent implantation was 81.98 ±9.15% and 12.52 ±8.70%, respectively (p < 0.001). Procedural success was achieved in all cases. One ischaemic stroke was observed at 30 days (1%, primary endpoint). At 1-year follow-up two myocardial infarctions and three deaths occurred with no additional stroke.

CONCLUSIONS

The OCEANUS study indicated the safety and efficacy of the MER™ stent during 30-day and 1-year follow-up in both symptomatic and asymptomatic patients. The majority of patients were event-free. However, larger cohort studies are needed to evaluate MER™ stents in detail.