nitinol and Carotid-Stenosis

The primary purpose of this study was the composite of major adverse events through 30 days post-index procedure or ipsilateral stroke from 30 days to 1 year (365 days). Presented here is the composite of death, stroke, and myocardial infarction (MI) through 30 days.. Rates of minor stroke have been higher with carotid artery stenting (CAS) compared with carotid endarterectomy (CEA). The study hypothesized that a stent with mesh covering may improve plaque stabilization during CAS, reduce plaque protrusion, and lead to reduced stroke rates.. The SCAFFOLD trial, a prospective, multicenter, single-arm clinical trial evaluating the GORE carotid stent (GCS), enrolled patients at increased risk for adverse events from CEA with severe carotid artery stenosis (defined as symptomatic ≥50% or asymptomatic ≥80%). The SCAFFOLD trial screening committee was implemented to determine adherence to the study protocol. Patients were evaluated for the primary endpoint, the composite of death, stroke, and MI through 30 days.. A total of 312 patients were enrolled, treated, and reviewed by the SCAFFOLD trial screening committee, of which 265 were included in the primary analysis population. The 30-day rate of death, stroke, or MI was 3.0% (95% confidence interval: 1.3% to 5.9%) and the stroke or death rate was 1.5%. The 30-day stroke rate was 1.1%. The 2 deaths in the study were not stroke related.. Low death, stroke, or MI rates were demonstrated with GCS in patients at high risk for CEA. The 30-day stroke rate of 1.1% suggests that the carotid stent mesh covering may reduce the neurologic events associated with CAS when used in appropriately selected patients.

Topics: Aged; Aged, 80 and over; Alloys; Carotid Stenosis; Endarterectomy, Carotid; Endovascular Procedures; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prospective Studies; Prosthesis Design; Risk Assessment; Risk Factors; Self Expandable Metallic Stents; Severity of Illness Index; Stroke; Time Factors; Treatment Outcome; United States

To evaluate patients characteristics, procedural details, perioperative outcomes, and midterm results of carotid artery stenting (CAS) performed with the Roadsaver/Casper stent (Terumo Corp, Tokyo, Japan) as compared to concurrent patients treated with other commercially available carotid stents.. This is a single-center, retrospective, nonrandomized study including 200 consecutive patients who underwent a total of 205 elective CAS procedures due to severe internal carotid artery stenosis between April 2015 and December 2018. Procedural data and outcomes for patients treated with the Roadsaver/Casper stent implantation (100 procedures, in 97 patients) vs first-generation carotid stents implantations (90 procedures, in 88 patients) were compared. Fifteen patients were treated with CGuard carotid stent (InspireMD, Tel Aviv, Israel), and outcomes were reported separately. Primary endpoints were the occurrence of major adverse cerebrovascular events (MACE), including death, ipsilateral stroke, and transitory ischemic attack (TIA). Secondary endpoints were the rate of intrastent stenosis, the need for reintervention, and the occurrence of adverse cardiovascular events, including myocardial infarction, arrhythmias, and need for inotropic support.. No difference in demographics and preoperative risk factors were observed between patients treated with and without the Roadsaver/Casper stent. The mean procedure time was shorter in the Roadsaver/Casper group (40.7±16.9 vs 49.4±27.3 minutes; p=0.008), while radial percutaneous access was more frequent (24% vs 5%; p<0.001). The rate of stroke/TIA/death at 30 days was 3% in the Roadsaver group vs 1% in the first-generation stent group (p=0.623). The primary patencyrate was 100% and 93.4% at 1- and 3-year of follow-up in the Roadsaver/Casper groupand 99% and 94.3% in the other stent group, respectively (p=0.95).. In this real-world cohort of patients undergoing CAS, the Roadsaver/Casper stent was used to treat more symptomatic and vulnerable carotid plaques as compared to other carotid stents. Nevertheless, patients treated with this low-profile dual-layer micromesh stent showed low events rates at both 30 days and follow-up, similar to that observed for other stents.

Topics: Alloys; Carotid Arteries; Carotid Stenosis; Humans; Retrospective Studies; Risk Factors; Stents; Stroke; Treatment Outcome

Endovascular treatment of carotid artery stenosis is a valuable alternative to open surgery, and the evolution of stent materials and cerebral protection devices significantly decreased postoperative neurological complications. Among these, the introduction of nitinol double-layer micromesh stent seems to guarantee a reduced perioperative and postoperative cerebral embolization. Long-term results are however still not available to make a global evaluation of these stents. We present the case of a 66-year-old female patient treated for asymptomatic carotid stenosis complicated by a symptomatic partial stent thrombosis occurred three months after carotid artery stenting.

Topics: Aged; Alloys; Anticoagulants; Asymptomatic Diseases; Carotid Stenosis; Computed Tomography Angiography; Embolic Protection Devices; Endovascular Procedures; Female; Humans; Platelet Aggregation Inhibitors; Prosthesis Design; Stents; Surgical Mesh; Thrombosis; Time Factors; Treatment Outcome

Stroke due to the release of embolic debris during the placement of a stent to correct carotid artery stenosis is a constant procedural and peri-procedural threat. The new all metal Casper stent has been created with two layers of nitinol, the inner layer of which has pores diminutive enough to prevent embolic release.. To evaluate the safety, effectiveness, and utility of the double layer nitinol Casper carotid artery stent in the treatment of patients with severe carotid artery stenosis.. 19 patients with severe internal carotid artery stenosis, 14 symptomatic and 5 asymptomatic, were treated with the Casper stent. After stent placement, angiographic and cone beam CT images were recorded in all patients.. The unique low profile delivery system allowed for easy stent placement, re-sheathing, and repositioning of the stent. The large cell external layer produced excellent apposition to the artery wall. The inner layer prevented prolapse of atherosclerotic debris through the device. Plaque coverage was achieved; residual stenosis ranged from 0% to 20%. Long term angiographic follow-up in 5 patients showed wall apposition of the device covering the lesion and no restenosis. There were no procedure related complications. Two patients experienced a delayed ischemic stroke, likely related to inconsistent medical management.. The Casper has been an excellent stent for the treatment of internal carotid artery stenosis and its internal micromesh layer has been effective in preventing plaque prolapse. It provides the flexibility of large cell stents and the inner layer provides maximum protection against plaque prolapse.

Topics: Aged; Aged, 80 and over; Alloys; Carotid Stenosis; Embolism; Female; Humans; Male; Middle Aged; Prosthesis Design; Stents; Stroke; Surgical Mesh; Treatment Outcome

In vitro models have suggested that stents affect atherosclerotic plaques symmetrically because of their outward radial forces. We evaluated the effects of stents on carotid plaque and the arterial wall using carotid ultrasound in carotid stenting patients to see whether these effects were borne out in vivo.. From a carotid stent database, 30 consecutive patients were selected. All had carotid Doppler ultrasound performed pre- and poststenting. The diameters of the lumen at the level of stenotic plaque pre- and poststenting, the dorsal and ventral plaque thickness, and of the outer arterial wall diameter were measured. Plaque thickness was measured at the level of maximal stenosis. Nonparametric tests were used to determine whether the stent effect and luminal enlargement were based on wall remodeling or on total arterial expansion.. The patients were followed for an average of 22 months. Eighteen patients were male, with an average age of 70 years. A total of 87% of patients were symptomatic ipsilateral to the side of stenosis. Nine patients had angioplasty intraprocedurally. The luminal diameter increased poststenting in the region of severe stenosis. Plaque thickness, both ventrally and dorsally, decreased poststenting, with no significant difference between the ventral and dorsal plaque effects. The outer arterial wall diameters did not change. The measured lumen in the stent increased over time poststenting.. Self-expanding nitinol stents alter the baseline ventral and dorsal plaque to a significant degree and do not significantly affect the native arterial wall and the overall arterial diameter.

Topics: Aged; Alloys; Blood Vessel Prosthesis; Carotid Stenosis; Female; Humans; Male; Middle Aged; Plaque, Atherosclerotic; Stents; Ultrasonography, Doppler

In this study, a polymeric membrane has been designed and developed for carotid stents to prevent detachment of emboli from the arterial wall and subsequent stroke, while maintaining side-branch flow. Prototypes of different geometrical design parameters have been fabricated and their performance has been evaluated in vitro under physiological pulsatile flow condition in a life-size silicone anastomotic model of carotid artery bifurcation. These evaluations include both quantitative and qualitative experimental (in vitro) assessments of emboli prevention capability, side-branch flow preservation, and flow visualization. The covered stents with the novel membrane demonstrated significantly higher emboli prevention capability than the corresponding bare nitinol stent as well as some earlier related designs, while preserving more than 93% of the original flow of the external carotid artery (ECA). Flow in the ECA through these covered stents was uniform without evidence of undesirable flow recirculation or retrograde flow that might predispose the vessel wall to intimal thickening and atherosclerotic plaque formation. This study demonstrated the potential of these novel covered stent designs for the treatment of carotid atherosclerotic stenosis and prevention of late embolic stroke. However, further in vivo investigations of biological effects and mechanical performance of this covered stent design (e.g., its thrombogenicity potential and biocompatibility) are warranted.

Topics: Alloys; Blood Flow Velocity; Carotid Arteries; Carotid Stenosis; Coated Materials, Biocompatible; Humans; Membranes, Artificial; Models, Anatomic; Models, Cardiovascular; Polymers; Prosthesis Design; Pulsatile Flow; Stents; Stroke; Thromboembolism

Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.

Topics: Alloys; Animals; Carotid Stenosis; Cell Adhesion; Cell Proliferation; Cells, Cultured; Chemokine CXCL1; Endothelium, Vascular; Mice; Oligopeptides; Stents

Several randomized trials of patients with carotid stenosis show increased adverse neurological events with stenting versus endarterectomy in the 30-day post-procedure. This study examines the incidence of new ischaemic lesions in patients treated in our centre using the new Roadsaver stent.. Between September 2015 and January 2016, 23 consecutive patients (age 74.3 ± 7.3 years, 17.4 % female) underwent carotid artery stenting with the Roadsaver stent, a nitinol double-layer micromesh device. A distal protection device was used in all cases. Diffusion-weighted magnetic resonance imaging was performed 24 h before, and 24 h and 30 days after the procedure. The 24-h post-procedure imaging showed 15 new ipsilateral ischaemic lesions in 7 (30.4 %) patients: median volume 0.076 cm. Protected stenting with micromesh Roadsaver stent showed good safety and efficacy in the treatment of carotid stenosis, with a low incidence of delayed embolic events and new ipsilateral ischaemic brain lesions. These preliminary results are encouraging, but need to be confirmed with larger populations.

Topics: Aged; Aged, 80 and over; Alloys; Brain Ischemia; Carotid Stenosis; Diffusion Magnetic Resonance Imaging; Equipment Design; Female; Humans; Incidence; Male; Middle Aged; Prospective Studies; Recurrence; Stents; Stroke; Treatment Outcome

Stent design may influence the outcomes, suggesting that adverse event rates vary according to free cell area and cell design. Open cell design technology of self-expandable stents, dedicated for carotid revascularisation has better deliverability, although closed cell technology is expected to cause fewer thromboembolic events.. To evaluate the feasibility and vascular response of novel, hybrid cell, self-expandable nitinol stents (MER®, Balton, Poland) implanted into porcine carotid arteries. Hybrid cell design combines open and closed cell technology.. All tested stents were implanted with 10% overstretch into 10 carotid segments of Polish domestic pigs. Control angiography was obtained immediately before and after vascular interventions as well as 28 days after the procedure. Thereafter, animals were sacrificed, and the treated segments were harvested and evaluated in the independent histopathology laboratory.. All stents were easily introduced and implanted, showing good angiographic acute outcome. At 28 days, in the angiography, all vessels were patent with no signs of thrombi or excessive neointimal formation, with the late lumen loss of -0.11 ± 0.3 mm and percentage diameter stenosis 10.18 ± 8.1%. There was a 10% increase in the vessel reference diameter when compared to baseline (4.57 ± 0.5 vs. 4.96 ± 0.3 mm, p < 0.01). In the histopathology, mean area stenosis was 17.4% and mean intimal thickness was 0.20 mm. At histopathology, the mean injury, inflammation, and fibrin scores were low. Endothelialisation was complete in all stents, and neointimal tissue appeared moderately mature as shown by the moderate mean neointimal smooth muscle score. Nonetheless, histopathology shows one stent affected by peri-strut granulomas and one stent affected by marked mineralisation.. The novel Polish self-expandable nitinol carotid stent with hybrid cell technology shows optimal biocompatibility and a vascular healing profile, and therefore may be introduced for first-in-man application.

Topics: Alloys; Angioplasty; Animals; Carotid Arteries; Carotid Stenosis; Hybrid Cells; Hyperplasia; Materials Testing; Models, Animal; Neointima; Patient Safety; Prosthesis Design; Stents; Sus scrofa

To investigate the possible role of stent selection and procedure-related vessel diameter changes in the development of persisting hemodynamic depression (PHD) and to demonstrate the effectiveness and safety of permanent pacemaker implantation in patients with refractory PHD.. Data from 584 procedures performed in 542 patients (398 men; mean age 67.3 years) between 2008 and 2011 using Wallstent, Precise, and Xact stents in a nonrandomized fashion were analyzed retrospectively. Cardiovascular risk factors and lesion, stent, and balloon characteristics were collected, and the pre- and postprocedure diameters of the common carotid artery (CCA) and internal carotid artery were measured. PHD was defined as any episode of hypotension (systolic blood pressure <90 mm Hg) and/or bradycardia (heart rate <60/min) lasting >6 hours. Risk factors for PHD were sought using logistic regression analyses; the results are presented as the odds ratio (OR) and 95% confidence interval (CI).. The incidence of PHD was 37.0% (216/584). Refractory PHD was encountered in 9 patients; among these, 6 were successfully treated with pacemaker implantation. A history of prior ipsilateral carotid endarterectomy (OR 0.44, 95% CI 0.22 to 0.87, p=0.019) and the presence of a contralateral high-grade stenosis (OR 0.12, 95% CI 0.02 to 0.95, p=0.045) were independent protective factors, while calcification (OR 1.5, 95% CI 1.03 to 2.18, p=0.034), involvement of the carotid bulb (OR 2.56, 95% 1.62 to 4.03, p<0.001), and implantation of a nitinol stent (adjusted OR 1.62, 95% CI 1.12 to 2.34, p=0.011) were independent risk factors for developing PHD after carotid artery stenting. The ratio of the post-/preprocedure CCA diameter (p=0.002), the stent to CCA diameter ratio (p=0.009), and the presence of residual stenosis (p=0.009) were significantly higher in the PHD group.. Stent selection and procedure-related changes in vessel diameter may have an influence on the development of PHD. Permanent pacemaker implantation is an effective treatment option in patients with refractory PHD.

Topics: Aged; Alloys; Angioplasty, Balloon; Body Mass Index; Bradycardia; Carotid Artery, Common; Carotid Artery, Internal; Carotid Stenosis; Female; Hemodynamics; Humans; Hypertension; Incidence; Male; Middle Aged; Platelet Aggregation Inhibitors; Postoperative Care; Preoperative Care; Retrospective Studies; Risk Assessment; Risk Factors; Stents; Treatment Outcome

Carotid artery stenting (CAS) has grown as a possible alternative for the treatment of extracranial cerebrovascular disease in the past decade. A preexisting contralateral carotid artery occlusion has been described as a risk factor for inferior outcomes after carotid endarterectomy, but its impact on CAS outcomes is less understood.. A retrospective review of 417 CAS procedures performed between May 2001 and July 2010 at a single center using self-expanding nitinol stents and mechanical embolic protection devices was conducted. Patients were divided into two groups, those with a preexisting contralateral carotid occlusion (group A, n = 39) versus those without a contralateral occlusion (group B, n = 378). Patient demographics and comorbidities as well as 30-day and late death, stroke, and myocardial infarction (MI) rates were analyzed. Mean follow-up was 4 years (range: 0-9.4 years).. Overall, mean age of the 314 men and 103 women was 70.5 years. In group A, there were two (5.1%) octogenarians and nine patients (23.1%) with symptomatic disease as compared with group B with 53 (14%) octogenarians and 121 (32%) patients with symptomatic disease. The overall 30-day death, stroke, and MI rates were 0.5%, 1.9%, and 0.7%, respectively. When comparing group A with group B, these results were not significantly different: death (0% vs. 0.5%), stroke (2.6% vs. 1.9%), and MI (0% vs. 0.8%). Long-term outcomes for groups A and B were also not significantly different: death (25.6% vs. 22.2%), stroke (5.3% vs. 3.4%), and MI (15.4% vs. 14%) (p = nonsignificant).. A preexisting contralateral carotid artery occlusion does not seem to adversely impact CAS outcomes.

Topics: Aged; Alloys; Angiography; Blood Vessel Prosthesis Implantation; Carotid Stenosis; Female; Follow-Up Studies; Humans; Male; Neural Tube Defects; Postoperative Complications; Retrospective Studies; Risk Factors; Stents; Stroke; Survival Rate; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Duplex; United States

To assess the differences in radial force of carotid stents and whether the length of the lesion influences the measurements.. Different models of tapered stents of similar size (length, 30 mm) were used. The tapered nitinol Acculink, Protégé, and Cristallo Ideale carotid artery stents and the straight, braided Elgiloy carotid Wallstent were compared. A measurement device consisting of three film loops along the stent body connected to aluminium rods with copper strain gauges was developed. Five stents of each type were deployed within 3-mm stenoses in simulated long (26 mm) and short (8 mm) stenoses.. In the short stenosis simulation, the greatest radial force was seen in the Protégé stent, at 3.14 N ± 0.45, followed by the Cristallo Ideale stent (1.73 N ± 0.51), Acculink (1.16 N ± 0.21), and Wallstent (0.84 N ± 0.10; P < .001). In the long stenosis simulation, peak radial force again was highest in the Protégé stent (1.67 N ± 0.37), but the Acculink stent was second (0.95 N ± 0.12) and the Wallstent third (0.80 N ± 0.06). The Cristallo Ideale stent, in contrast to the short stenosis simulation, produced the least radial force (0.44 N ± 0.13) in the long stenosis simulation (P = .001).. Radial forces exerted by carotid stents vary significantly among stent designs. Differences between stent types are dependent on the length of the stenosis. An understanding of radial force is necessary for a well-considered choice of stent type in each individual patient.

Topics: Alloys; Angioplasty; Carotid Stenosis; Humans; Materials Testing; Prosthesis Design; Stents; Stress, Mechanical; Transducers, Pressure

Topics: Alloys; Carotid Stenosis; Equipment Design; Humans; Polytetrafluoroethylene; Stents; Stroke; Treatment Outcome

Topics: Aged; Alloys; Angioplasty, Balloon; Carotid Artery, Internal; Carotid Stenosis; Humans; Male; Prosthesis Design; Prosthesis Failure; Stents; Tomography, X-Ray Computed

Previously, the Stenting and Angioplasty with Protection of Patients with High Risk for Endarterectomy (SAPPHIRE) randomized trial showed that carotid artery stenting (CAS) was not inferior to carotid endarterectomy (CEA) in the treatment of high-surgical risk patients.. The primary objective of the SAPPHIRE Worldwide Registry is to evaluate 30-day major adverse events (MAE) after CAS performed by physicians with varied experience and utilizing a formal training program. Data will be analyzed on the overall patient population and by high-risk inclusion criteria.. SAPPHIRE Worldwide is a multicenter, prospective, postapproval registry to evaluate CAS with distal protection in patients at high-risk for surgery using the Cordis PRECISE Nitinol Stent and ANGIOGUARD XP/RX Emboli Capture Guidewire. Participating physicians are encouraged to treat patients according to their standard of practice and consistent with current Food and Drug Administration-approved labeling.. Enrollment began in October 2006. Data are available on the first 2,001 patients enrolled and followed to 30 days. Of these patients, the mean age was 72.2 +/- 9.75 yr; 62% were male; and 27.7% were symptomatic. Entry criteria for surgical high-risk included anatomic (n = 716), physiologic (n = 918), or both risk factors (n = 327). At 30-day follow-up, the MAE was 4.4% (death 1.1%, stroke 3.2%, MI 0.7%) for the overall population. Patients with anatomic risk had a significantly lower 30-day MAE than patients with physiologic risk (2.8% vs. 4.9%, P = 0.0306), respectively.. While the number of physicians performing CAS continues to increase, MAE rates seen in this registry (4.4%) are well within an acceptable range, as was first seen in the SAPPHIRE randomized trial (4.8%). A significant decrease in MAE was seen in patients with anatomic risk compared with physiologic risk factors. The SAPPHIRE Worldwide Registry supports the use of CAS as an alternative to CEA in patients who are at high-risk for surgery due to anatomic risk factors.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty; Canada; Cardiovascular Diseases; Carotid Stenosis; Clinical Competence; Education, Medical; Embolism; Endarterectomy, Carotid; Female; Humans; Logistic Models; Male; Middle Aged; Odds Ratio; Patient Selection; Practice Guidelines as Topic; Prospective Studies; Prosthesis Design; Registries; Risk Assessment; Risk Factors; Stents; Time Factors; Treatment Outcome; United States

Topics: Alloys; Angioplasty; Cardiovascular Diseases; Carotid Stenosis; Clinical Competence; Education, Medical; Endarterectomy, Carotid; Humans; Patient Selection; Practice Guidelines as Topic; Prospective Studies; Prosthesis Design; Risk Assessment; Risk Factors; Stents; Time Factors; Treatment Outcome

The aim of this study was to compare the clinical and ultrasound outcome of carotid artery stenting at 2-year follow-up in patients treated with open-cell nitinol stents versus patients treated with closed cell stainless steel stents.. This was a non-randomized, retrospective study including 123 patients in whom 132 carotid stent-procedures were performed. Nine patients were treated bilaterally. All patients presented with severe asymptomatic (80%) or symptomatic (>70%) carotid artery stenosis and were treated by carotid angioplasty and stent placement with or without filter embolic protection system. Follow-up consisted of physical evaluation at 1, 6, 12 and 24 months and assessment of the stent patency by ultrasound examination at 6, 12 and 24 months after the stent procedure.. In 72 procedures a closed cell stainless steel stent was implanted, in the remaining 60 procedures an open cell nitinol stent was placed. In 8 patients with a stainless steel stent (11%) and in 6 patients with a nitinol stent (10%) a stroke occurred during the follow-up period (P=0.79). Ultrasound examination revealed an in-stent restenosis of 50% to 80% in the stainless steel group (N.=9, 15%) and in the nitinol group (N.=10, 17%) (P=0.7).. At 2-year follow-up after carotid artery stenting, there is no difference in clinical outcome or in stent patency among patients treated with open versus closed cell design stents. Subsequently the type of carotid stent design does not seem to impact the overall midterm outcome after carotid artery stenting.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty; Carotid Stenosis; Female; Humans; Kaplan-Meier Estimate; Male; Prosthesis Design; Recurrence; Reoperation; Retrospective Studies; Risk Assessment; Severity of Illness Index; Stainless Steel; Stents; Stroke; Time Factors; Treatment Outcome; Ultrasonography

CT angiography (CTA) and MR angiography (MRA) are increasingly used methods for evaluation of stented vessel segments. Our aim was to compare CTA, contrast-enhanced MRA (CE-MRA) at 1.5T, and CE-MRA at 3T for the visualization of carotid artery stents and to define the best noninvasive imaging technique as an alternative to conventional angiography for each stent.. CTA and CE-MRA appearances of 18 carotid artery stents of different designs and sizes (4.0 to 10.0 mm) were investigated in vitro. For each stent, artificial lumen narrowing (ALN) was calculated.. With CE-MRA at 3T and at 1.5T, ALN in most nitinol stents was lower than that in the groups of stainless steel and cobalt alloy stents. In most nitinol stents and in both cobalt alloy stents, ALN was lower on CE-MRA at 3T than at 1.5T. In all stainless steel stents, ALN was lower on CTA than on CE-MRA. With CTA and CE-MRA, in most stents ALN decreased with increasing stent diameter.. CTA and CE-MRA evaluation of vessel patency after stent placement is possible but is considerably impaired by ALN. Investigators should be informed about the method of choice for every stent. Stent manufacturers should be aware of potential artifacts caused by their stents during noninvasive diagnostic methods such as CTA and CE-MRA.

Topics: Alloys; Carotid Stenosis; Cerebral Angiography; Cobalt; Humans; In Vitro Techniques; Magnetic Resonance Angiography; Phantoms, Imaging; Reproducibility of Results; Stainless Steel; Stents; Tomography, X-Ray Computed

To assess the effect of stent type on hypotension and bradycardia after carotid artery stent placement.. A retrospective analysis on a prospectively maintained database was conducted in 256 patients (126 men; mean age, 71.8 years +/- 8.6; 194 de novo lesions) undergoing carotid artery stent placement between January 1996 and January 2007 by using self-expanding stents. Braided Elgiloy stents (Wallstents) were used in 44 of the 256 patients (17.2%) and slotted-tube nitinol stents were deployed in 212 (82.8%). Bivariate and multivariable logistic regression models were used to determine the influence of stent design on procedural and 24-hour hypotension and bradycardia.. Procedural hemodynamic depression (HD) was encountered in 73 of the 256 patients (28.5%) due to hypotension in 24 (9.4%), bradycardia in 12 (4.7%), or both in 37 (14.5%) patients. Rates of procedural hypotension were 11.3% with nitinol stents and 0% with braided Elgiloy stents (P = .0188). Persistent postprocedural HD occurred in 91 of the 256 patients (35.5%) due to hypotension in 40 patients (15.6%), bradycardia in 23 (9.0%), or both in 28 (10.9%). Within a multivariable analysis adjusted for clinically relevant factors affecting rates of HD, the use of braided Elgiloy stents was associated with a decreased rate of procedural hypotension (odds ratio: 0.165; 95% confidence interval: 0.038, 0.721; P = .017). Procedural hypotension and bradycardia were not correlated to incidence of major adverse events but were associated with an increased duration of hospital stay (P = .0059 and P = .0335, respectively).. Nitinol stents are associated with a higher risk of hypotension as compared to braided Elgiloy stents during carotid artery stent placement.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Bradycardia; Carotid Stenosis; Female; Hemodynamics; Humans; Hypotension; Incidence; Length of Stay; Logistic Models; Male; Odds Ratio; Prosthesis Design; Retrospective Studies; Risk Assessment; Risk Factors; Stents; Time Factors; Treatment Outcome

Topics: Aged; Alloys; Angiography, Digital Subtraction; Angioplasty, Balloon; Carotid Stenosis; Humans; Male; Prosthesis Design; Prosthesis Failure; Recurrence; Reoperation; Stents; Treatment Outcome

To report the results from a prospective multicenter registry evaluating the safety and performance of a new hybrid stent specifically engineered for carotid indications.. Between October 18, 2006, and March 28, 2007, 124 patients (88 men; mean age 71.8+/-7.3 years, range 52-87) underwent Cristallo Ideale stent implantation at 4 expert sites in Italy and Germany. Eligibility criteria included >60% symptomatic and >80% asymptomatic carotid stenosis. Different cerebral protection devices were utilized (proximal protection and distal filters). The primary endpoint was the rate of 30-day major adverse neurological events, defined as major and minor stroke and neurological death by independent neurological assessment. All adverse events were adjudicated by an independent clinical event committee.. Stent deployment was completed successfully in all the cases without documented technical failure. There were no neurological events during the procedures. Thirty-day follow-up was available for 119 (96.0%) patients [2 (1.6%) were lost to follow-up and 3 (2.4%) died from non-neurological causes unrelated to the device or procedure]. There were no major adverse neurological events within 30 days, but 2 (1.6%) device-/procedure-related transient ischemic attacks were reported (both resolved completely in <24 hours). Four (3.2%) other non-neurological events (anemia requiring transfusion, worsening of pre-existing chronic renal failure, acute access site thrombosis, and monocular vision disturbance) were reported in the study period.. The Cristallo Ideale carotid stent is safe and effective in the periprocedural period. Its newly designed hybrid structure seems to support the rationale of combining adequate plaque scaffolding with high vessel adaptability.

Topics: Aged; Aged, 80 and over; Alloys; Carotid Stenosis; Female; Humans; Male; Middle Aged; Prospective Studies; Prosthesis Design; Registries; Safety; Stents; Stroke; Treatment Outcome

We present the first reported case of a carotid artery stent fracture where a Nitinol stent was used for the management of carotid artery stenosis. An 83-year-old man underwent right carotid artery stenting in July 2005. On follow-up ultrasound, stenosis of the right internal carotid artery was noted. In January 2006, he underwent left carotid artery stenting and at this procedure, precontrast assessment of the right neck revealed a complete fracture through the waist of the stent in the right internal carotid artery. This fractured segment correlated with the area of stenosis reported at the previous ultrasound. In July 2006, this gentleman underwent successful removal of the carotid stent with uneventful carotid endarterectomy and synthetic patch repair. Carotid artery stenting is a newer and alternative modality to carotid endarterectomy for the treatment of carotid artery stenting. More data are emerging to support its safety and efficacy. An unexpected complication can happen with any procedure and complications help define the follow-up management of subsequent patients undergoing this procedure.

Topics: Aged, 80 and over; Alloys; Blood Vessel Prosthesis Implantation; Carotid Artery, Internal; Carotid Stenosis; Device Removal; Endarterectomy, Carotid; Graft Occlusion, Vascular; Humans; Male; Prosthesis Design; Prosthesis Failure; Radiography; Stents; Ultrasonography, Doppler, Color

This study examined whether physicians with varying carotid stent experience would obtain safety and efficacy outcomes as good as those from the pivotal SAPPHIRE trial following participation in a comprehensive carotid stent training program.. This study was performed as a condition of approval study for the PRECISE(R) Nitinol Stent and the ANGIOGUARD XP Emboli Capture Guidewire.. Patients at high surgical risk who were either symptomatic with >or=50% stenosis or asymptomatic with >or=80% stenosis of the common or internal carotid artery received carotid artery stenting with distal emboli protection using the PRECISE Nitinol Stent and the ANGIOGUARD XP Emboli Capture Guidewire. Physicians were qualified based on either prior experience in carotid stenting with the ANGIOGUARD XP Emboli Capture Guidewire or following participation in a formal training program. The primary endpoint of major adverse events (MAE) at 30 days (death, myocardial infarction (MI), or stroke) was tested for non-inferiority compared with an objective performance criterion (OPC) of 6.3% established from the stent cohort of the SAPPHIRE trial.. The 30-day MAE rate was 5.0%, meeting the criteria for non-inferiority to the prespecified OPC (95% CI [3.9%, 6.2%] P<0.001). Asymptomatic patients (N=1,158, 78.2%) had similar outcomes to the overall results (MAE 4.7%). Outcomes were similar across levels of physician experience, carotid stent volume, geographic location, presence/absence of training program.. Utilizing a comprehensive training program, carotid artery stenting by operators with differing experience in a variety of practice settings yielded safety and efficacy outcomes similar to those reported in the SAPPHIRE trial.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty; Cardiovascular Diseases; Carotid Stenosis; Clinical Competence; Device Approval; Education, Medical; Embolism; Equipment Design; Female; Humans; Incidence; Male; Product Surveillance, Postmarketing; Prosthesis Design; Registries; Severity of Illness Index; Stents; Time Factors; Treatment Outcome; United States

The placement of self-expanding nitinol stents in the carotid artery is rapidly emerging as a minimally invasive alternative in the treatment of cervical carotid artery occlusive disease. Fractures of balloon-expandable stents after placement in the carotid artery have been previously documented. The authors report on a single case of early stent fracture and complete mid-body disruption of a self-expanding stent associated with a significant restenosis necessitating repeat intervention after carotid artery stent placement for a de novo atherosclerotic lesion.

Topics: Aged; Alloys; Angiography, Digital Subtraction; Angioplasty, Balloon; Carotid Stenosis; Humans; Male; Prosthesis Design; Prosthesis Failure; Recurrence; Reoperation; Stents; Treatment Outcome

To present a patient in whom severe external carotid artery (ECA) stenosis causing ocular ischemia was treated with a drug-eluting stent.. A 55-year-old woman with severe, diffuse atherosclerosis presented with impaired left ocular perfusion and amaurosis fugax. Duplex ultrasonography and angiography documented bilateral occlusion at the origin of the internal carotid arteries, bilateral subtotal ECA stenoses, and subtotal distal left common carotid artery (CCA) restenosis following endarterectomy. Percutaneous revascularization of the left ECA and CCA stenoses was performed using a short coronary balloon-expandable sirolimus-eluting stent and a self-expanding nitinol stent, respectively. The procedure was uneventful, and the ocular symptoms resolved. At 6 months, the patient remained asymptomatic, with angiographically patent stents.. Drug-eluting stenting may be a novel option to treat symptomatic ECA stenosis.

Topics: Alloys; Amaurosis Fugax; Angiography, Digital Subtraction; Blood Vessel Prosthesis Implantation; Carotid Artery, Common; Carotid Stenosis; Coated Materials, Biocompatible; Endarterectomy, Carotid; Eye; Female; Humans; Immunosuppressive Agents; Ischemia; Middle Aged; Postoperative Complications; Reoperation; Sirolimus; Stents; Vascular Patency

To report the complications, rescue procedures, and consequences related to the use of an embolus protection filter during carotid artery stenting (CAS).. A retrospective review was undertaken of 72 patients (58 men; mean age 70.0+/-8.2 years, range 56-87) with extracranial atherosclerotic carotid stenosis who underwent 77 CAS procedures under filter protection. Filter-related events and rescue procedures according to each procedural step were retrospectively evaluated on CAS angiograms. In addition, neurological events and outcomes were also assessed.. CAS using a filter was successful in 99% of cases, and the overall rate of minor stroke (n=1), major stroke (0), or mortality (n=1) was 2.6% at 30 days. Filter placement was successful in all cases. However, arterial tortuosity made it difficult for a filter to pass through the stenosis in 1 case; this was overcome with an additional supportive wire (0.018-inch). Filter-related events were flow impairment in 6 (7.8%), filter wedging in the catheter tip in 4 (5.2%), vasospasm >50% narrowing in 7 (9.1%), filling defects within the filter membrane in 5 (6.5%), retrieval failure with the provided retriever in 3 (3.9%), and insecure retrieval without filter collapse in 2 (2.6%). Flow impairment caused drowsy mentality and impaired verbal response in 4, which resolved after prompt filter retrieval. All the cases of filter wedging were resolved with a catheter pulled down into the stented segment to separate the filter element from the catheter tip. Significant vasospasm and filling defects were spontaneously resolved in all cases after filter retrieval. Inability to pass a retriever catheter through a stent was overcome with curved 5-F catheter manipulation in all 3 cases.. The use of a filter during CAS may induce various angiographic or technical events at each step. For a severely stenotic and tortuous carotid lesion with difficult access, a filter may become trapped or irretrievable during flow arrest. Physicians should be aware of the preventive and rescue maneuvers to counter filter-related events, perhaps even considering another type of protection mechanism or carotid endarterectomy.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Atherosclerosis; Blood Vessel Prosthesis Implantation; Carotid Stenosis; Endarterectomy, Carotid; Equipment Design; Equipment Failure; Female; Filtration; Humans; Intracranial Embolism; Male; Middle Aged; Radiography; Retrospective Studies; Risk Factors; Safety; Stents; Stroke; Treatment Outcome; Vascular Patency; Vasospasm, Intracranial

Treatment of dissecting pseudoaneurysms of the distal cervical internal carotid artery with preservation of the parent artery by using stents or coils has become routine. Tortuosity remains a significant obstacle to successful endovascular treatment in some cases. We report the use of a stent-coil technique to treat a nonhealing dissecting pseudoaneurysm and associated stenosis with anatomic preservation of a redundant loop involving the stented arterial segment. This was accomplished by using a Neuroform dedicated intracranial stent.

Topics: Adult; Alloys; Aneurysm, False; Aspirin; Carotid Artery, Internal, Dissection; Carotid Stenosis; Combined Modality Therapy; Dominance, Cerebral; Embolization, Therapeutic; Female; Follow-Up Studies; Humans; Ischemic Attack, Transient; Platelet Aggregation Inhibitors; Radiography; Stents

Conformity between self-expanding Wallstents and vascular anatomy is limited. Because of a lack of longitudinal flexibility, straightening effects on vascular curves occur and may result in stent-induced kinking. Our purpose was to evaluate the conformity of self-expanding stents with the course and endoluminal surface of silicone models of the normal human carotid artery.. Five different types of self-expanding carotid stents were implanted into simplified pulsatile perfused silicone models of the carotid bifurcation. The models embody elastic properties of the vessel wall similar to those of normal human arteries. All stents had the same nominal diameter and length and bridged the external carotid artery origin as well as a consecutive curve at the initial segment of the internal carotid artery. Conventional radiographs of the model were compared before and after stent placement to record changes of shape and course of the silicone artery. Dehiscences between stent filaments and arterial wall were measured on digital subtraction angiograms of the model.. Implantation of braided Wallstents or the Expander with continuous filaments induced considerable straightening effects on the bifurcation angle, as well as on the curves of the internal carotid artery. Segmented designs of modular nitinol stents complied better with vascular tortuosity and showed improved adaption between stent and the endoluminal surface of the model.. Model experiments show that segmented nitinol stents improve the conformity between the prosthesis and vascular anatomy, and confirm new carotid stent concepts as an alternative to the Wallstent.

Topics: Alloys; Angioplasty, Balloon; Carotid Artery, External; Carotid Artery, Internal; Carotid Stenosis; Chromium Alloys; Compliance; Equipment Failure Analysis; Humans; Models, Cardiovascular; Prosthesis Design; Stents

To determine the efficacy of a covered stent prototype designed for protected carotid angioplasty to reduce cerebral embolization.. The covered stent tested is made of nitinol, coated with a polyurethane membrane (MembraX trade mark; porous size 80 micro m). In a bench-top model (flow-rate 650 ml/min, pulsatile flow [dicrote] 123 Pulses/min, pressure 100/60 mm Hg [mean pressure 80 mmHg]) with inserted human carotid (n = 6) stent implantation was performed (8/32 mm). Passed particles (mg) were determined in the effluent of a 100 micro m filter prior to intervention, after stent deployment and after final dilation (5 mm).. When stenting carotid arteries obtained from human cadavers, the highest rate of particle embolization was measured while crossing the lesion with the delivery device (6,8 mg; for all p < 0,05), embolization after additional balloon angioplasty and particle rates measured in the effluent filter prior covered stent placement were significantly lower (3,8 mg; p < 0,05). Branches of the external carotid artery remained patent in all cases.. The introduced concept of covered stent protected carotid angioplasty with the MembraX trade mark prototype has proven promising results for low cerebral embolization rates ex vivo. Further evaluations using an animal model and a miniaturization of the delivery device are warranted prior to human use.

Topics: Adult; Alloys; Angioplasty, Balloon; Cadaver; Carotid Arteries; Carotid Artery, Common; Carotid Artery, External; Carotid Artery, Internal; Carotid Stenosis; Humans; Intracranial Embolism; Polyurethanes; Stents

Our objective was to assess the technical feasibility and the clinical results of internal carotid artery (ICA) stenting using a nitinol self-expanding stent (SMART stent). In 13 patients 13 high-grade stenoses of the internal carotid artery were treated via an implantation of a SMART stent. In all cases a predilation of the stenosis and a postdilation within the stent were performed. Follow-up examinations were carried out in all patients after a period of 6 months. In each case the implantation of the stent was performed without technical complications. In 12 of 13 cases the stent was placed in the patients' internal carotid artery, in 1 case from the internal to the common carotid artery (CCA). The average degree of stenosis of 78% (70-95%) was reduced to an average of 2.8% (0-21%). The 6-month follow-up angiography showed an average degree of restenosis of 11.8% (0-29%) in 8 of 13 patients. Duplex sonography in the remaining 5 patients demonstrated patent stents. One patient showed brief neurological symptoms during the intervention. No further complications occurred during follow-up time. Treatment of internal carotid artery stenosis with the SMART stent seems technically feasible, safe, and promises long-term patency.

Topics: Aged; Aged, 80 and over; Alloys; Blood Vessel Prosthesis Implantation; Carotid Arteries; Carotid Stenosis; Female; Humans; Male; Middle Aged; Prospective Studies; Radiography; Stents; Treatment Outcome

To evaluate the feasibility, safety, and efficacy of the TRAP Vascular Filtration System (VFS) during carotid interventions as a deterrent to embolic complications.. Thirty-one consecutive patients (18 men; mean age 72 +/- 8 years) gave informed consent to undergo elective percutaneous angioplasty and stenting of the extracranial carotid artery protected by the TRAP VFS, a nitinol basket filter system.. The TRAP VFS was delivered and retrieved safely in all patients; procedural success for carotid stenting was 100%. In 3 (9.7%) cases, the filters were positioned after lesion predilation. Nearly half (13, 41.9%) of the retrieved filters contained visible plaque debris that histology identified as cholesterol crystals, fibrin material, atheromatous plaque, and macrophage foam cells. There were no symptomatic major or minor neurological complications encountered in this cohort during hospitalization.. Our data indicate that percutaneous dilation and stenting of the carotid artery protected by TRAP VFS appears to be feasible, safe, and effective in preventing cerebral embolization.

Topics: Aged; Alloys; Angioplasty, Balloon; Carotid Arteries; Carotid Stenosis; Feasibility Studies; Female; Filtration; Humans; Intracranial Embolism; Male; Prospective Studies; Stents

Angioplasty and stenting are becoming increasingly accepted techniques for the treatment of carotid stenosis. However, the optimal stent for carotid intervention is not known.. We compared the short- and intermediate-term results of carotid stenting using either nitinol or stainless-steel self-expanding stents in 178 high surgical risk patients undergoing carotid stenting at our institution. Of these 178 patients, eighty-nine received stainless-steel stents and 89 received nitinol stents. The groups were similar with respect to age, gender, diabetes, hypertension, left ventricular function, and symptom status. There were more patients with contralateral carotid occlusion in the nitinol stent group. Independent neurological evaluation was performed in all patients pre- and post-carotid stenting.. At 6 months, there was a similar incidence of stroke (3.3% versus 2.2%) in the stainless-steel group and nitinol stent group, respectively. There was higher 6-month mortality noted in the stainless-steel stent group, but there were no neurological deaths in either group.. In a single-center patient cohort with similar baseline characteristics, patients receiving nitinol stents and stainless-steel stents had similar neurological outcomes.

Topics: Aged; Aged, 80 and over; Alloys; Carotid Artery, Common; Carotid Artery, External; Carotid Stenosis; Equipment Safety; Female; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Incidence; Male; Middle Aged; Ohio; Postoperative Complications; Radiography; Stents; Stroke; Survival Analysis; Time Factors; Treatment Outcome

Topics: Alloys; Carotid Artery, Common; Carotid Artery, External; Carotid Stenosis; Equipment Safety; Graft Occlusion, Vascular; Humans; Postoperative Complications; Stents; Stroke; Treatment Outcome

We describe our initial clinical experience using the newly available self-expanding, Nitinol, shape-memory-, alloy-recoverable-technology (SMART) stent in treating carotid artery occlusive disease. Five stents were used in four carotid arteries in four consecutive patients with carotid stenosis of at least 70%. Technical success (<20% residual stenosis) was achieved in all cases. No procedural complications specifically related to use of the SMART stent were encountered. All patients remained symptom-free, with no evidence of transient ischemic attacks or new strokes during an average follow-up period of 6 months. Excellent performance of the SMART stent for the endovascular treatment of carotid artery stenosis has been shown based on our early experience. Validation with greater numbers and longer-term follow-up is required. The specific technical characteristics, potential advantages, and disadvantages of this stent are discussed and compared with other currently used carotid artery stents.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Carotid Stenosis; Female; Humans; Male; Middle Aged; Stents; Vascular Surgical Procedures