nitinol and Embolism

A novel, low-profile filter embolic protection device was deployed in 26 patients who underwent stent deployment for saphenous vein graft stenoses in a multicenter trial. Major adverse cardiovascular events were observed in only 2 patients (7.7%) and angiographic flow grades were improved.

Topics: Aged; Alloys; Coronary Angiography; Embolism; Female; Filtration; Graft Occlusion, Vascular; Humans; Male; Saphenous Vein; Stents; 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 the setting of ST-elevation myocardial infarction (STEMI), epicardial vasoconstriction and thrombus load may lead to stent undersizing and malapposition after primary percutaneous coronary intervention (PPCI), which can both be responsible for stent thrombosis or restenosis. Aggressive stent deployment can, on the other hand, cause distal embolisation and the no-reflow phenomenon. The purpose of our study was to evaluate the safety and feasibility of a novel self-expanding stent by assessing the clinical, angiographic and intravascular outcomes after stent deployment at three days and at six months follow-up.. This prospective, multicentre, non-randomised study enrolled 25 STEMI patients undergoing PPCI; a nitinol, self-expanding, coronary stent (STENTYS® stent; STENTYS, Paris, France) was used in all patients. Angiography and intravascular ultrasound (IVUS) or optical coherence tomography (OCT) were performed immediately after stent deployment, after three days and at six months. Primary safety endpoints were mortality, reinfarction, stent thrombosis and stroke at discharge and at six months. The primary feasibility endpoints were technical, device and procedural success, and stent apposition at three days and six months. Secondary endpoints included distal embolisation, binary restenosis, ischaemia-driven target lesion revascularisation (TLR) and late lumen loss (LLL). There were no adverse events at discharge or at six months. Technical, device and procedural success were 100%, 96% and 96%, respectively. IVUS showed a significant vasodilatation distal to the culprit lesion at three-day follow-up (+19%), with a concordant expansion of the implanted stent (+18%), p≤0.001 for both values. One case of distal embolisation was reported. There were no cases of late stent malapposition at six months. In-stent and in-segment LLL were 0.71±0.71 mm and 0.58±0.61 mm. Binary restenosis was 25%, ischaemia-driven TLR was 12%.. This study shows that the use of the STENTYS® self-expanding stent is safe and feasible in STEMI patients. Three days after the procedure, the stent expanded to the same extent as the epicardial vasodilatation and appeared completely apposed to the vessel wall. This could be of benefit in preventing stent thrombosis in the setting of STEMI.

Topics: Adult; Aged; Alloys; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Embolism; Europe; Feasibility Studies; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prospective Studies; Prosthesis Design; Recurrence; Stents; Thrombosis; Time Factors; Tomography, Optical Coherence; Treatment Outcome; Ultrasonography, Interventional

The purpose of this study was to evaluate the safety and efficacy of debris-capture for distal protection using the FilterWire EZ Embolic Protection System (Boston Scientific, Mountain View, CA) with the additional aim to further define the incidence of distal embolization during superficial femoral artery (SFA) interventions. A prospective, single-centre registry was designed to evaluate the performance of the FilterWire EZ in capturing debris during standard SFA percutaneous intervention. The PRO-RATA study included 30 patients suitable for PTA (Fontaine IIb to III or Rutherford I to II classification). The primary end points were occurrence of distal embolization or decreased runoff, improvement in ankle-brachial index ankle-brachial index (ABI) after the procedure, and number of filters containing emboli. Secondary end points included major adverse events (i.e., procedure- or device-related death and/or clinical target lesion revascularisation), device delivery, deployment success, and incidence of embolic recovery (patients with device success exhibiting embolic protection in the filter). Procedural success was determined as ≤30% residual stenosis with no worsening of distal runoff as determined on angiography. A total of 29 patients (age 66.2 ± 12 years; total no. of limbs = 30; total no. of lesions = 30) suitable for PTA were enrolled in the study between February 2007 and March 2008. There were 26 patients with claudication (Fontaine IIB) and 3 patients with stage IV peripheral vascular disease. In one patient, lesions in both legs were treated. No procedural or device-related complications occurred. The average degree of stenosis was 86 ± 7%. Stenosis length ranged from 8 to 88 mm. The average degree of residual stenosis was 10 ± 10%. ABI improved from 0.56 ± 0.16 to 0.92 ± 0.19 (P < 0.05). No restenosis or dissection was seen at 1-month ultrasound follow-up. Macroscopic debris was found in 27 of 30 filters of all distal protection devices used in all 29 patients. Debris particle size ranged from 90 to 2000 μm (1200 ± 640). Histological debris analysis showed platelets, erythrocytes, inflammatory cells, extracellular matrix, and cholesterol as being the major components of emboli. Additional immunochemistry showed no correlation between lesion morphology and debris components. The FilterWire EZ is easy and safe to handle. The system caused no complications. In all cases, macroscopic debris was captured. Using a distal protection device during fem

Topics: Aged; Alloys; Angiography; Angioplasty; Embolism; Female; Femoral Artery; Filtration; Humans; Immunohistochemistry; Leg; Male; Peripheral Vascular Diseases; Prospective Studies; Registries; Stents; Treatment Outcome

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

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

Percutaneous transluminal renal angioplasty and stent placement with use of a coronary protection device was performed in a total of four patients with hypertension (n = 4) and/or renal insufficiency (n = 3) referred for revascularization of five renal arteries. Renal revascularization was successful in all five renal arteries (100%), but renal revascularization under protection by the FilterWire EX was achieved in only three of five renal arteries (60%). In one of these three, only a suboptimal seal was achieved between the vessel wall and the filter basket. Nevertheless, use of the device was safe and fibrin and/or cholesterol fragments were retrieved from three renal arteries. The FilterWire EX needs to be modified for the renal circulation to achieve the full theoretical advantages of these systems in this vascular bed.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Cholesterol; Embolism; Female; Fibrin; Filtration; Humans; Hypertension; Male; Middle Aged; Polyurethanes; Renal Artery Obstruction; Renal Insufficiency; Retrospective Studies; Stents; Treatment Outcome

To assess the technical feasibility and efficacy of distal embolus protection with an intra-aortic filter during stent-graft repair in a patient diagnosed with a shaggy aorta.. In a 75-year-old man with a severely atherosclerotic thoracic aortic aneurysm, stent-graft repair was combined with transposition of the arch branches to the ascending aorta under thoracotomy. A filtration-type embolus protection device with a nitinol basket and polyester fabric was introduced through a 12-F sheath and opened in the supraceliac aorta during the stent-graft procedure; it was safely pulled back into the sheath after the stent-grafts were implanted. The stent-graft repair was successful, and abundant atheromatous debris was captured in the filter. Neither procedure-related embolic events nor neurological deficits were observed.. Use of the intra-aortic filter device to prevent distal embolism during thoracic stent-graft repairs may be feasible and efficacious in severely atherosclerotic patients.

Topics: Aged; Alloys; Aortic Aneurysm, Thoracic; Atherosclerosis; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Contrast Media; Embolism; Feasibility Studies; Humans; Male; Prosthesis Design; Stents; Tomography, X-Ray Computed; Treatment Outcome

Distal embolization of plaque particulate liberated during stenting may cause periprocedural complications. The number, size, and volume of debris released during stenting, however, have not been quantified, rendering embolic protection approaches empiric. We used a novel method of microparticle size assessment to measure volume and characterize individual sizes of particles captured by the PercuSurge GuardWire balloon or a vascular filter during saphenous vein graft stenting.. Braided nitinol filters (average distal pore size 100 microns) were used in 47 saphenous vein grafts in 44 patients. The PercuSurge GuardWire was used in 17 saphenous vein grafts in 16 patients. Particulate debris was subjected to microparticle size analysis (RapidVue, Beckman Coulter). All samples contained particulate debris. For both filter and GuardWire populations, most particles were <100 microm in longest dimension (87% and 90% of particles, respectively), and the distribution of particle sizes was identical. Total embolic load per lesion for both filters and GuardWire aspirates was also similar: median embolic load per filter was 16 mm3 (range 2 to 84 mm3). Median embolic load per GuardWire was also 16 mm3 (range 7 to 42 mm3). Histopathologic analysis demonstrated that most samples contained plaque elements and platelet-rich thrombus.. During saphenous vein graft interventions, particulate retrieved with a vascular filtering device or an occlusion balloon was similar in amount and character. This supports the notion that unless soluble mediators play an important role in adverse acute clinical events after stenting, the clinical efficacy of filtering devices may be equal to that of occlusion devices.

Topics: Alloys; Calibration; Catheterization; Coronary Artery Bypass; Coronary Artery Disease; Embolism; Equipment Design; Filtration; Foam Cells; Humans; Intraoperative Complications; Microspheres; Particle Size; Randomized Controlled Trials as Topic; Saphenous Vein; Stents; Suction; Thrombosis

The results of infra-inguinal intervention for atherosclerotic occlusive disease have not changed dramatically in the last 15 years despite the advent of many different designs of uncovered stents. "Plain old balloon angioplasty" remains the treatment of choice for short lesions (<3 cm) with good morphologic characteristics. Stents have improved suboptimal angioplasty results somewhat, but results in longer lesions >5 cm have remained poor in most series. Although there are no endografts currently approved for arterial use by the FDA, expanded polytetraflouroethylene (ePTFE) covered endoprostheses are available and their use in the femoropopliteal arteries can dramatically improve the results of endovascular treatment for longer lesions and allow one to treat vascular ruptures and aneurysms. In this article, we will review the published results for the use of endografts in the femoropopliteal arteries and describe what we believe to be the current indications for their use.

Topics: Alloys; Aneurysm; Angioplasty, Balloon; Arterial Occlusive Diseases; Embolism; Femoral Artery; Humans; Polytetrafluoroethylene; Popliteal Artery; Radiography; Stents; Vascular Patency

The authors performed this study to evaluate the (a) ability of a prototype temporary inferior vena caval (IVC) filter to trap and retain emboli in an ex vivo flow circuit, (b) feasibility of filter placement and removal via a superficial vein in sheep, and (c) intermediate-term effects of the filter on the insertion vein and at the filter site.. In an iliocaval circuit, embolus capture with the prototype filter was compared to that with a Greenfield filter. In addition, prototype filters were placed into the infrarenal IVC in six sheep. Placement via a superficial venous route was initially attempted. Inferior vena cavography was performed weekly, and filters were removed after 2, 3, or 4 weeks (n = 2 each). Two weeks after the filters were removed, vena cavograms were obtained, the animals were sacrificed, and the IVC was evaluated at pathologic examination.. The prototype filter captured all emboli, and the Greenfield filter captured 70%-100% of emboli. Successful placement via a superficial venous route was accomplished in only two sheep owing to small vein caliber; four filters were placed via a deep vein. Adverse events included perifilter thrombus, insertion site infection, and caudal migration. Two sheep died before filter removal owing to sepsis and anesthetic complications. The filters in the remaining four sheep were easily and successfully removed. Five sheep had stenosis at the filter site, and fibrosis with acute and chronic inflammation was seen at microscopic examination.. The prototype filter trapped emboli as well as the Greenfield filter. Insertion via a superficial route, however, is possible only if the access vein is of an adequate size.

Topics: Alloys; Animals; Embolism; Equipment Design; Feasibility Studies; Radiography; Sheep; Vena Cava Filters; Vena Cava, Inferior

To assess whether the use of a prosthesis covered by a Dacron sheath might prevent pseudointimal hyperplasia in a transjugular intrahepatic portosystemic shunt (TIPS).. A TIPS procedure was performed in nine pigs, after creation of a portal vein microembolization model of portal hypertension, by using a Dacron-covered nitinol stent. The first centimeter on the lower extremity of this specially made prototype was uncovered, to avoid portal vein thrombosis. Three weeks later, the seven surviving animals underwent transjugular hemodynamic and angiographic follow-up and were then killed for gross and histologic evaluation.. Shunt insertion was possible in all pigs; two died of complications of the procedure. After 3 weeks only two shunts were patent, although a 50%-60% narrowing of the initial portion of the shunt was present; the remaining shunts were occluded. Histologic examination showed pseudointimal hyperplasia associated, in the cases of occlusion, with a luminal thrombosis.. This Dacron-covered stent did not prevent pseudointima formation over the stent and resulted in a high early occlusion rate, probably related to a pronounced tissue fibrotic response likely due to Dacron-induced inflammation.

Topics: Alloys; Angiography; Animals; Disease Models, Animal; Embolism; Equipment Design; Fibrosis; Follow-Up Studies; Graft Occlusion, Vascular; Hemodynamics; Hepatic Artery; Hyperplasia; Hypertension, Portal; Polyethylene Terephthalates; Portal Vein; Portasystemic Shunt, Transjugular Intrahepatic; Stents; Surface Properties; Survival Rate; Swine; Thrombosis; Tunica Intima; Vascular Patency