FilterWire EZ Research Articles

Safety and Risk Factors of Carotid Artery Stenting with Simple Distal Filter Protection: A Single-Center Retrospective Study.

Carotid artery stenting embolic protection devices offer various options, among which distal filter protection is the simplest and easiest to handle. However, compared to balloon protection systems, distal filter protection has more embolic complications. Therefore, we explored the risk factors of distal filter protection, intending to achieve a safer carotid artery stenting. This retrospective study was conducted to identify prognostic factors following carotid artery stenting with only distal filter protection from July 2010 to June 2021. Information on patient background, procedures and devices, and complications was collected using medical records. The data pertaining to 187 patients were analyzed after excluding the data of patients in whom other protection devices (8 cases) were used. We used FilterWire EZ as the first choice for embolic protection device and SpiderFX when the patients had difficult-to-cross lesions. The patients' mean age was 71.9 ± 6.9 years, and 72 (38.5%) were symptomatic. Symptomatic (odds ratio: 2.02, p = 0.035) and difficult-to-cross lesions (odds ratio: 3.63, p = 0.0013) were factors independently associated with symptomatic complications. This retrospective single-center study established independent prognostic factors for carotid artery stenting with distal filter protection. For patients with symptomatic lesions and severe stenosis or bends that are difficult to pass through, it is necessary to be careful when performing carotid artery stenting with distal filter protection.

Reconsidering the Treatment Strategy for Carotid Artery Stenting with FilterWire EZ: Focusing on the Risk Factors for Flow Impairment during the Procedure

FilterWire EZ（FW-EZ）でのcarotid artery stenting（CAS）においてflow impairmentを起こす要因は明確ではない．本研究ではFW-EZにおけるflow impairmentを起こす要因について後方視的に評価を行い，FW-EZでのCASの治療適応について再検討した．

Complications and failure modes of coronary embolic protection devices: Insights from the MAUDE database.

There is limited data on complications associated with the use of coronary embolic protection devices (EPDs). We queried the Manufacturer and User Facility Device Experience database between November 2010 and November 2020 for reports on coronary EPDs: Spider FX (Medtronic, Minneapolis, MN) and Filterwire EZ (Boston Scientific, Natick, MA). We retrieved 119 reports on coronary EPD failure (Spider FX n = 33 and Filterwire EZ n = 86), most of which (78.2%) occurred during saphenous vein graft interventions. The most common failure mode was inability to retrieve the EPD (49.6%), with the filter trapped against stent struts in 76.2% of the cases. Other device complications included filter fracture (28.6%), failure to cross (7.6%), failure to deploy (7.6%), and failure to recapture the filter (3.4%). Filter fracture (54.5 vs. 29.1%) and failure to recapture (9.1 vs. 2.1%) were more commonly reported, while failure to deploy the filter (0 vs. 10.5%) was less commonly reported with the Spider-FX. The most common modes of failure of coronary EPDs are the failure of retrieval (49.6%), followed by the filter fracture (28.6%). When using EPDs, careful attention to the technique is essential to avoid failures and subsequent complications.

Very Low Rate of New Brain Lesions After Vulnerable Carotid Artery Stenting Cases Using Only FilterWire EZ as Distal Embolic Protection

Although carotid artery stenting (CAS) has been widely acknowledged as an effective alternative option for patients at high risk of carotid endarterectomy, embolic stroke is a major complication of CAS. Several reports have emphasized that distal protection filter alone is associated with a high risk of embolic complications of CAS with vulnerable plaque. Thus, relatively complicated protection systems have recently been recommended to prevent distal embolic complications. However, those protection systems require many steps, which, themselves, can also cause complications. The FilterWire EZ embolic protection device (EPD) for use in CAS was approved for national health insurance coverage in Japan in 2010. Since then, we have been using it as an EPD in all CAS procedures, even those with vulnerable plaque. The medical records of 80 patients who had undergone CAS from February 2014 to September 2019 at Moriyama Memorial Hospital were retrospectively reviewed. Emergent cases with distal mechanical thrombectomy were not included. We enrolled patients whose target lesion was vulnerable as evaluated by magnetic resonance imaging and who had undergone diffusion-weighted imaging studies the next day. Of the 80 patients, 60 had met the inclusion criteria. No symptomatic embolic complications developed, and only 5 patients (8.3%) had shown new lesions on diffusion-weighted imaging after CAS. The rate of new lesions after CAS with vulnerable plaque was much lower than that in previous studies. We meticulously analyzed the data to determine the predictive factors. The FilterWire EZ as an EPD for CAS is quite safe, even for vulnerable carotid stenosis.

PC058. A Novel Aortic Arch Flow Model to Test the Efficacy of Cerebral Embolic Protection Devices Using Transcranial Doppler

Clinically apparent stroke occurs in up to 6% of patients undergoing thoracic endovascular aortic repair and up to 4% of patients undergoing carotid artery stenting. However, clinically silent cerebral infarction is seen on postoperative diffusion-weighted magnetic resonance imaging in >60% of patients undergoing thoracic endovascular aortic repair and leads to an increased risk of future stroke and dementia. Embolic protection devices are associated with lower stroke rates and smaller volume of ischemic lesions on diffusion-weighted magnetic resonance imaging. We created a novel aortic arch flow model and tested the efficacy of the FilterWire EZ (Boston Scientific, Marlborough, Mass) using transcranial Doppler ultrasound. By employing a three-dimensional printed aortic arch, we created a closed-circuit flow model that can simulate continuous and pulsatile blood flow (Fig, A-C). Dissolved cornstarch particles simulate circulating red and white blood cells, which typically range in size from 6 to 15 μm, to provide a background signal for detection of solid and gaseous emboli on transcranial Doppler ultrasound (Fig, D and E). A 38-μm filter placed in series ensures that injected microparticles do not recirculate and the circuit is deaired. We then prepared and deployed a FilterWire EZ, a uniform 110-μm pore filter commonly used during carotid artery stenting, according to the instructions for use. Embozene Microspheres (Boston Scientific) of known sizes were diluted in saline to 1 mL of particles per 10 mL of solution. High-intensity transient signals (HITS) were recorded during filter deployment, injection of 1 mL of solution, and filter retrieval. This process was repeated for Embozene particles of 75-, 100-, 250-, and 400-μm diameters. Each continuous 1-second shower of emboli was counted as 15 HITS. Despite preparation of the FilterWire EZ according to instructions for use, there were on average 41 ± 7 (range, 31-49) HITS during filter deployment and 7 ± 7 (range, 1-17) HITS during filter retrieval. Average number of HITS during injection was 87 ± 130 (range, 4-315), and more HITS were seen distal to the filter on injection of microparticles that were smaller than the 110-μm pore size (142 ± 150 vs 5 ± 1; P = .31). Mean velocity (cm/s) of the fluid decreased by 18% ± 2% after filter deployment and 50% ± 34% during injection of microparticles and returned to baseline after filter retrieval. We created and validated a novel aortic arch flow model. HITS were seen during all stages of the procedure using the FilterWire EZ. This model can be used to test the efficacy of all available embolic protection devices and methods of deairing stent grafts.

Therapeutic mechanism and regularity of “treating angina pectoris from spleen” in Coronary Heart Disease caused by “spleen deficiency and phlegm”

Although Mo.Ma Ultra is an embolic protection device for interrupting the anterograde blood flow to the internal carotid artery, incomplete blood stagnation is often observed. We report the effectiveness of the combined use of a distal filter protection device and Mo.Ma Ultra (Medtronic, Minneapolis, MN).Our case series comprises 10 consecutive patients (11 carotid arteries) who underwent carotid artery stenting (CAS) using Mo.Ma Ultra and FilterWire EZ (Boston Scientific, Natick, MA).The superior thyroid artery originated from the proximal side of the bifurcation of the common carotid artery, except for 1 artery. Although complete blood stagnation was observed in 6 arteries, filter debris was detected in 3 of these 6 arteries. Positive postoperative findings on diffusion-weighted magnetic resonance imaging were observed in 3 cases (3 arteries). Only 1 patient had transient neurological deficits.The combined use of a distal filter protection device and Mo.Ma Ultra could provide a more reliable embolic protection in CAS.

Adverse events and modes of failure related to the FilterWire EZ Embolic Protection System: Lessons learned from an analytic review of the FDA MAUDE database.

To assess the commonly reported complications and failure modes for FilterWire EZ Embolic Protection Devices (EPD) by analyzing the postmarketing surveillance data from the Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database. EPDs prevent distal embolization of atheroembolic materials during percutaneous interventions resulting in reduced microvascular obstruction and improved microcirculation while maintaining tissue perfusion. The FilterWire EZ EPD (Boston Scientific, Natick, MA) is approved for use in interventions of de novo saphenous vein grafts (SVG) and carotid artery stenosis. Robust data on the commonly reported complications and failure modes associated with the FilterWire EZ device are limited. The MAUDE database was queried from September 1, 2008, through September 30, 2018, for FilterWire EZ system, yielding 474 reports. After exclusion of duplicate and incomplete reports, 464 device reports were included in the final analysis. Device-related adverse events were most commonly reported for carotid (n = 281) and SVG (n = 101) interventions. The most commonly reported major complications were: ischemic stroke (n = 57), vessel perforation or dissection (n = 12), death (n = 8), and myocardial infarction (n = 5). Minor complications included: hypotension (n = 68), bradycardia (n = 41), and vasospasm (n = 27). The most commonly reported failure modes were: detachment and/or damage of the device components (n = 118), device entrapment (n = 90), and stent-related issues (n = 46). Analysis of the MAUDE dataset is helpful in identifying the commonly reported adverse events and failure modes of FilterWire EZ devices. This platform serves as an important tool for both physicians and manufacturers to optimize device performance and clinical outcomes.

500.08 Adverse Events and Modes of Failure Associated with the Filterwire EZ Embolic Protection System; The Utility of the FDA MAUDE Database

Embolic protection devices (EPDs) prevent distal embolization of atherothrombotic material during percutaneous interventions resulting in reduced microvascular obstruction, improved microcirculation, and tissue perfusion. The FilterWire EZ Embolic Protection System (Boston Scientific, Natick, MA) is

Efficiency test of current carotid embolic protection devices

Embolic protection devices were developed to reduce the risk of stroke during carotid artery stenting. The aim of this study was to test the capture efficiency of five embolic protection devices under reproducible in vitro conditions. The setup consisted of silicone tubes representing the vessel modeling round and oval cross sections. Spherical polystyrene particles (150 μm, COOH-coating) were used to simulate the plaque. The particles were inserted in a clean water circuit and either captured by the device or collected in a glass filter. The missed particles were counted by laser obscuration as a measure of device leakage. The systems Angioguard RX, RX Accunet, FiberNet, FilterWire EZ and EmboshieldNAV were analyzed. At the round cross section, FilterWire EZ demonstrated the highest capture efficiency (0% of missed particles) and RX Accunet the lowest, at 34%. The amount of leaked particles increased to 22% for FilterWire EZ and 89% for Angioguard RX during the test with the oval cross profile.

Immunohistochemical Analysis of Debris Captured by Filter-Type Distal Embolic Protection Devices for Carotid Artery Stenting

Little is known about the micro-debris captured in filter-type distal embolic protection devices (EPD) used for carotid stenting (CAS). This study aimed to determine the histological and immunohistochemical characteristics of such debris by using a new liquid-based cytology (LBC) technique. Fifteen patients who underwent CAS using a filter-type distal EPD (FilterWire EZ; Boston Scientific, Marlborough, MA, USA) were included in the study. After gross inspection of each recovered filter device, micro-debris were collected using a new LBC technique (SurePath; TriPath Imaging, Inc., Burlington, NC). Histological and immunohistochemical analysis of the recovered debris was performed. The pre- and postoperative brain magnetic resonance imaging and neurological status of each patient were also reviewed. No patient developed ipsilateral symptomatic stroke due to a thromboembolic event. All 15 patients (100%) had microscopically identifiable debris in the filters, whereas gross inspection detected visible debris only in 5 patients (33.3%). Histological analysis revealed various types of structural components in an advanced atheromatous plaque, including fragments of fibrous cap, calcified plaque, smooth muscle cells, and necrotic tissue fragment infiltrated with monocytes and macrophages. Filter-type EPDs may contribute to reducing the risk of CAS-related embolic events by capturing micro-debris even when gross inspection of the recovered filter shows no visible debris in the device.

Effectiveness of the Combined Use of Distal Filter Protection Device and Mo.Ma Ultra: Technical Note

Although Mo.Ma Ultra is an embolic protection device for interrupting the anterograde blood flow to the internal carotid artery, incomplete blood stagnation is often observed. We report the effectiveness of the combined use of a distal filter protection device and Mo.Ma Ultra (Medtronic, Minneapolis, MN). Our case series comprises 10 consecutive patients (11 carotid arteries) who underwent carotid artery stenting (CAS) using Mo.Ma Ultra and FilterWire EZ (Boston Scientific, Natick, MA). The superior thyroid artery originated from the proximal side of the bifurcation of the common carotid artery, except for 1 artery. Although complete blood stagnation was observed in 6 arteries, filter debris was detected in 3 of these 6 arteries. Positive postoperative findings on diffusion-weighted magnetic resonance imaging were observed in 3 cases (3 arteries). Only 1 patient had transient neurological deficits. The combined use of a distal filter protection device and Mo.Ma Ultra could provide a more reliable embolic protection in CAS.

Outcomes between 30 Days and 1 Year after Carotid Artery Stenting Using FilterWire EZ: Clinical Results and Diffusion-weighted MRI Findings in 262 Consecutive Patients

Outcomes between 30 Days and 1 Year after Carotid Artery Stenting Using FilterWire EZ: Clinical Results and Diffusion-weighted MRI Findings in 262 Consecutive Patients

A Manual Carotid Compression Technique to Overcome Difficult Filter Protection Device Retrieval during Carotid Artery Stenting

We investigated the incidence of embolic protection device retrieval difficulties at carotid artery stenting (CAS) with a closed-cell stent and demonstrated the usefulness of a manual carotid compression assist technique. Between July 2010 and October 2013, we performed 156 CAS procedures using self-expandable closed-cell stents. All procedures were performed with the aid of a filter design embolic protection device. We used FilterWire EZ in 118 procedures and SpiderFX in 38 procedures. The embolic protection device was usually retrieved by the accessory retrieval sheath after CAS. We applied a manual carotid compression technique when it was difficult to navigate the retrieval sheath through the deployed stent. We compared clinical outcomes in patients where simple retrieval was possible with patients where the manual carotid compression assisted technique was used for retrieval. Among the 156 CAS procedures, we encountered 12 (7.7%) where embolic protection device retrieval was hampered at the proximal stent terminus. Our manual carotid compression technique overcame this difficulty without eliciting neurologic events, artery dissection, or stent deformity. In patients undergoing closed-cell stent placement, embolic protection device retrieval difficulties may be encountered at the proximal stent terminus. Manual carotid compression assisted retrieval is an easy, readily available solution to overcome these difficulties.

Carotid stenting with distal protection in high-surgical-risk patients: one-year results of the ASTI trial.

This prospective, multicenter, nonrandomized study evaluated the periprocedural and 1-year outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Adapt Carotid Stent plus FilterWire EZ distal protection catheter (Boston Scientific Corporation, Natick, MA). The study enrolled 100 patients (32 symptomatic, 63 asymptomatic, 5 unknown) at high risk for carotid endarterectomy due to prespecified anatomical criteria and/or medical comorbidities. Thirty-day and 1-year follow-up included clinical evaluation, carotid duplex ultrasound, and independent neurologic and NIH stroke scale assessments. One-year endpoints included the composite rate of major adverse events (MAE), defined as death, stroke, and myocardial infarction (MI) and the rates of late ipsilateral stroke (31-365 days), target lesion revascularization, and in-stent restenosis. Of the 100 enrolled patients, technical success was achieved in 90.9 % (90/99). The 30-day MAE rate (5.1 %) consisted of major stroke (2.0 %) and minor stroke (3.1 %); no deaths or MIs occurred. The 1-year MAE rate (12.2 %) consisted of death, MI, and stroke rates of 4.4, 3.3, and 8.9 %, respectively. Late ipsilateral stroke (31-365 days) rate was 1.1 %. Symptomatic patients had higher rates of death (11.1 vs. 1.7 %) and MI (7.4 vs. 1.7 %), but lower rates of major (7.4 vs. 10.0 %) and minor stroke (0.0 vs. 6.7 %), compared with asymptomatic patients. Results through 1 year postprocedure demonstrated that carotid artery stenting with Adapt Carotid Stent and FilterWire EZ is safe and effective in high-risk-surgical patients.

Pathophysiology of flow impairment during carotid artery stenting with an embolus protection filter

Carotid artery stenting (CAS) is a well-accepted treatment for atherosclerotic stenosis of carotid arteries. Since the occurrence of distal embolization with CAS is still a major concern embolus protection devices (EPD) are usually employed during the procedure. We examined two types of embolus protection filters (Angioguard XP (AG); Filterwire EZ (FW)) and evaluated the function. Thus, the filter was examined postoperatively and the cause of intraoperative flow impairment was evaluated. CAS was performed for 54 patients with carotid artery stenosis (55 lesions: 25 AG; 27 FW; 3 others). After completing CAS the filter membrane was stained with hematoxylin-eosin (HE) solution and removed from the filter strut. Once mounted on a glass slide the filter was evaluated under a microscope. The area occupied with debris was measured and the relationship to intraoperative flow impairment was evaluated. Furthermore, the relationship between perioperative ischemic complications and intraoperative flow impairment was statistically analyzed. Microscopic observation of the slide revealed the pore density of the FW was 1.5 times higher than that of the AG and the filter area of the FW was 2.5 times wider than than the AG. HE staining facilitated characterization of the debris composition. The area occupied with debris was significantly more in the AG (0.241 ± 0.13 cm(2)) than in the FW (0.129 ± 0.093 cm(2)). Thus, fibrin was significantly more precipitated in the AG. Flow impairment occurred in 6 AG cases (24.0 %) and 4 FW cases (14.8 %). It was induced by filter obstruction in the AG and by vasospasms in the FW. Three cases treated with AG (12.0 %) were complicated with cerebral infarction and all of them were related to flow impairment. One FW case (3.7 %) was complicated with cerebral infarction in presence of preserved flow throughout the intervention. Filter function is different according to each design. The cause of flow impairment was attributable to filter obstruction in the AG group and to vasospasms in the FW group. Filter obstruction tends to result in cerebral infarction.

Carotid artery stenting and patient outcomes: the CABANA surveillance study.

ObjectivesThe purpose of the prospective, multicenter, nonrandomized CABANA study was to evaluate periprocedural clinical outcomes in high surgical risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EZ Embolic Protection System by a diverse group of clinicians.BackgroundThere is a need for additional evidence evaluating carotid artery stenting (CAS) performed by operators with various experience and training levels.MethodsThe study enrolled symptomatic (≥50% carotid artery stenosis) and asymptomatic (≥80% carotid stenosis) patients at high risk for carotid endarterectomy. Study centers were grouped into three tiers based on previous CAS experience while individual operators were grouped by their CAS training. The primary endpoint was the 30-day composite of major adverse events [MAEs; including stroke, death, and myocardial infarction (MI)]. Individual event rates were evaluated across the overall study, and by center experience and physician training tier.ResultsOf 1,097 enrolled patients, 1,025 were evaluable for 30-day MAE rate. The stroke rate (3.3%) was a major contributing factor in the overall MAE rate (4.6%). Mortality was 1.3% and the MI rate was 0.5%. There was no statistically significant association between MAE rates among the center experience tiers (P = 0.61) nor among the operator training categories (P = 0.26).ConclusionsCAS with the Carotid WALLSTENT and FilterWire EZ yielded a low 30-day MAE rate that did not differ significantly across operator experience and training levels. Clinicaltrials.gov identifier: NCT00741091. © 2014 Wiley Periodicals, Inc.

E-065 Clinical Treatment Result of Carotid Artery Stenting in Japan: Comparison of Periprocedural Ischemic Complication by Embolic Protection Devices

Carotid artery stenting (CAS) was approved in Japan in October 2007. Since then, several embolic protection devices (EPD) and stents for CAS have become available.We investigated the clinical treatment results...

Transvenous extraction of an eight-year-old ventricular lead accidentally implanted into the left ventricle

Incorrect implantation of a ventricular pacemaker (PM) lead into the left ventricle (LV) is a known problem associated with permanent pacing. The optimal management of such cases identified late has not been clearly established. Generally acceptable management options are: open-chest cardiac surgery using cardio-pulmonary bypass, chronic anticoagulation and antiplatelet-drugs therapy. Rarely, the problem is solved by percutaneous LV lead extraction. We present a case of a patient with DDD pacing and ventricular lead implanted incorrectly into the LV apex region via an atrial septal defect eight years ago. Chronic PM pocket infection developed after replacement of the device. Both leads were extracted percutaneously, and the embolic protection system (Filter-Wire EZ, Boston Scientific) was used to reduce cerebral circulation embolism. The hardest connective tissue adhesions affecting the lead and the anodal ring were found in the LV. Less dense surrounding fibrous tissue around the lead was present at all levels of the venous course of the lead and in the right atrium. Very small fragments of apparently connective tissue remnants were found in cerebral circulation protection filters, and had been removed after the procedure. We conclude that old, permanently implanted LV leads may be extracted percutaneously, especially when there is an increased risk of cardiac surgery, or where the patient's consent for surgical treatment is lacking. In order to perform the procedure it is recommended to establish a cerebral protection system and intraoperative transoesophageal echocardiography which are mandatory for successful lead removal.

Early ischemic brain lesions after carotid angioplasty and stenting on diffusion-weighted magnetic resonance imaging study

Summary Aim: The aim of the paper is to evaluate the appearance of the new early ischemic lesions in the brain after carotid angioplasty and stenting on diffusion-weighted magnetic resonance imaging, and their relationship with clinical and procedural factors. Methods: Carotid artery stenting (CAS) procedures performed by a single interventional cardiologist in years November 2006 to January 2013 were evaluated retrospectively. In total, 227 procedures for 211 patients (mean age 69.8 ± 8.5 years) were performed, from which 171 (75.3%) for male and 56 (24.7%) for female patients. Seventy-two (34.1%) patients had symptomatic stenosis of carotid artery. The following protection systems to avoid the distal microembolism were used during the CAS: (1) Filters: FilterWire EZ (Boston Scientific Corporation); Emboshield NAV (Abbott Vascular); SpideRX (EV3); Defender (Medtronic); FiberNet Filter (Invatec-Medtronic); (2) Occlusion MoMa Baloon System (Invatec-Medtronic). Acute ischemic damages of the brain before and after CAS procedure were diagnosed using magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) sequences. Sixty-five (30.8%) patients underwent MRI test. Exact and asymptomatic χ2 criteria were applied for testing the hypothesis of inter-dependency of the symptoms. Results: Forty-six (70.8%) patients had new ischemic foci in the brain on MRI DWI after CAS procedures. Among those patients, focal damage of the brain was diagnosed in 36 (78.3%) cases; linear damage of the brain - in 9 (19.6%) patients; ipsilateral damage of the brain - in 37 (80.4%) patients; bilateral damage of the brain - in 16 (34.8%) patients, 38 (82.6%) patients were diagnosed with forebrain damage; 4 (8.7%) patients were diagnosed with damage of brainstem; 5 (10.9%) patients were diagnosed with cerebellum damage. Clinical symptoms of brain damage were diagnosed only for 2 (4.3%) patients. Focal damage of the brain was significantly less frequent only for aortic arch type 1, if compared with aortic arch type 2 and 3: 64.3%, 93.3% and 100.0%, respectively (p < 0.05). Focal damage of the brain occurred least in patients (28.6%) with Emboshield NAV protection type, if compared to other types of protection (71.4-100.0%). Linear >10mmbrain damage was less frequent when using FilterWire EZ, Emboshield NAV and SpideRX protection type. Ipsilateral ischemic brain damage also occurred less frequent when using Emboshield NAV protection type; bilateral damage occurred less frequent when using FilterWire EZ, Emboshield NAV and SpideRX protection type. Ischemic forebrain damage was also diagnosed less often in patients for whom protection type FilterWire EZ and Emboshield NAV was applied. Conclusions: Most frequent findings by MRI after CAS procedures were focal, ipsilateral and forebrain damage (about 80%), but less than 5% patients had clinical symptoms. In the case of aorta arch type 1 focal ischemic damage of the brain was significantly less frequent, then in aortic arch type 2 and 3. The localization and extent of brain damage was associated with the type of protection systems that have been used.

Carotid artery stenting without post-stenting balloon dilatation

PurposeTo evaluate the clinical outcome and MRI findings after carotid artery stenting (CAS) without post-dilatation.MethodsBetween May 2005 and April 2012, a total of 169 consecutive patients (61.4% symptomatic) underwent 176...