nitinol and Carotid-Artery-Diseases

The number of peripheral procedures is increasing at a rapid pace and in a variety of vessels. This review will discuss current findings in carotid intervention and drug-eluting stents in superficial femoral arteries (SFA).

Topics: Alloys; Carotid Artery Diseases; Coronary Restenosis; Drug-Eluting Stents; Endarterectomy, Carotid; Femoral Artery; Humans; Immunosuppressive Agents; Risk Factors; Sirolimus; Stents; Vascular Patency

This study sought to evaluate the feasibility of the CGuard Carotid Embolic Protective Stent system-a novel thin strut nitinol stent combined with a polyethylene terephthalate mesh covering designed to prevent embolic events from the target lesion in the treatment of carotid artery lesions in consecutive patients suitable for carotid artery stenting.. The risk of cerebral embolization persists throughout the carotid artery stenting procedure and remains during the stent healing period.. A total of 30 consecutive patients (age 71.6 ± 7.6 years, 63% male) meeting the conventional carotid artery stenting inclusion criteria were enrolled in 4 centers in Germany and Poland.. The primary combined endpoint was the procedure success of the CGuard system and the number and volume of new lesions on the ipsilateral side assessed by diffusion-weighted magnetic resonance imaging at 48 h post-procedure and at 30 days. The secondary endpoint was 30-day major adverse cardiac or cerebrovascular events (death, stroke, or myocardial infarction). Protection devices were used in all procedures. Procedure success was 100%, with 0% procedural complications. The 30-day major adverse cardiac or cerebrovascular events rate was 0%. New ipsilateral ischemic lesions at 48 h occurred in 37.0% of patients and the average lesion volume was 0.039 ± 0.08 cm(3). The 30-day diffusion-weighted magnetic resonance imaging showed complete resolution of all but 1 periprocedural lesion and only 1 new minor (0.116 cm(3)) lesion in relation to the 48-h scan.. The use of the CGuard system in patients undergoing carotid artery stenting is feasible. In addition, the benefit of using CGuard may extend throughout the stent healing period.

Topics: Aged; Alloys; Angioplasty; Carotid Artery Diseases; Diffusion Magnetic Resonance Imaging; Embolic Protection Devices; Feasibility Studies; Female; Germany; Humans; Intracranial Embolism; Male; Middle Aged; Poland; Polyethylene Terephthalates; Prospective Studies; Prosthesis Design; Risk Factors; Stents; Stroke; Surgical Mesh; Time Factors; Treatment Outcome

Saccular aneurysm of the extracranial internal carotid artery is rare. We present a 56-year-old lady presented with a progressively enlarging pulsatile swelling over the right neck, and the right internal carotid artery aneurysm was successfully treated with trans-carotid endovascular stenting of right common to right carotid artery using a self-expanding nitinol base ePTFE covered stent (COVERA Plus™ stent, Bard, Tempe, USA). The external carotid artery was prophylactically embolised to prevent back bleeding. New generation covered stents have consistently improved flexibility and conformability, and this is to our knowledge the first reported case in the world's literature of using this type of self-expanding nitinol base ePTFE covered stent in endovascular stenting of carotid artery aneurysms, with excellent short-term results.

Topics: Aneurysm; Carotid Artery Diseases; Carotid Artery, Internal; Endovascular Procedures; Female; Humans; Middle Aged; Stents; Treatment Outcome

Our group recently developed a novel covered carotid stent that can prevent emboli while preserving the external carotid artery (ECA) branch blood flow. However, our recent in vitro side-branch ECA flow preservation tests on the covered stents revealed the need for further stent frame design improvements, including the consideration to crimp the stent to a low profile for the delivery of the stent system and having bigger cells. Hence, the current work aims to design new bare metal stents with bigger cell size to improve the crimpability and to accommodate more slits so that the side-branch flow could be further increased. Three new stent designs were analyzed using finite element analysis and benchmarked against two commercially available carotid stents in terms of their mechanical performances such as crimpability, radial strength, and flexibility. Results indicated that the new bare metal stent designs matched well against the commercial stents. Hence our new generation covered stents based on these designs can be expected to perform better in side-branch flow preservation without compromising on their mechanical performances.

Topics: Alloys; Angioplasty; Blood Flow Velocity; Carotid Artery Diseases; Computer Simulation; Computer-Aided Design; Finite Element Analysis; Materials Testing; Models, Cardiovascular; Prosthesis Design; Prosthesis Failure; Regional Blood Flow; Stents; Stress, Mechanical

We aimed to evaluate the feasibility and safety of performing percutaneous carotid stent implantation with a newly designed double-layer stent using transradial slender 5Fr techniques. We recruited 10 consecutive patients who underwent percutaneous carotid stenting using nitinol double-layer micromesh (Roadsaver) stents. Mean age of patients was 66 years. Seven patients had ≥2 high-risk criteria according to SAPPHIRE classification. Indication was neurologic symptoms in 7 and severe lesion without symptoms in 3 cases. Type 2 aortic arch was present in 8 patients and type 1 in 2 patients. Access was right radial artery in 9 cases and right ulnar artery in 1 case. Right carotid artery was stented in 4 cases and left carotid artery in 6 cases. Embolic protection device (EPD) was used in 6 cases. Nine stents were successfully delivered using 5Fr destination sheath (n = 7) or shuttle sheath (n = 2), and 1 was implanted using Mo-Ma 8Fr proximal EPD. Procedural success was obtained in all cases with only 1 case of temporary vasospasm due to distal EPD. Total procedural time was 21 minutes (13 to 30 minutes) with filter time of 5 ± 1 minutes. Fluoroscopy time was 8 minutes (5 to 12 minutes) and contrast volume was 150 ml (100 to 200 ml). Hospital stay was 1 ± 1 day with 4 patients discharged on the same day of the procedure. Using right transradial approach and slender 5Fr techniques, this new double-layer micromesh stent can be implanted in left and right carotid arteries with promising results.

Topics: Aged; Aged, 80 and over; Alloys; Carotid Artery Diseases; Catheterization, Peripheral; Cohort Studies; Embolic Protection Devices; Feasibility Studies; Female; Fluoroscopy; Humans; Length of Stay; Male; Middle Aged; Operative Time; Prospective Studies; Radial Artery; Stents; Surgical Mesh

To evaluate the efficacy, tolerance, and outcomes of covered stents in the treatment of carotid blowout syndrome (CBS) in head and neck cancer patients.. Individual retrospective cohort study.. We retrospectively reviewed the medical and image files of all 20 consecutive head and neck cancer patients treated with covered stent grafts for CBS. Six acute, 12 impending, and two threatened cases of CBS were treated in patients who all had previously received radiation therapy. We evaluated the feasibility, hemostatic efficacy, survival without bleeding, and complications.. The etiologies of CBS were as follows: group 1, 13 carotid axis (common or internal carotid artery) pseudoaneurysms and one rupture; group 2, six patients with no identifiable source of bleeding on angiography but with a threatened carotid axis on computed tomography (CT). In all patients, a polytetrafluoroethylene-covered nitinol stent graft (Fluency; Bard/Angiomed GmbH & Co, Karlsruhe, Germany) was successfully placed. All of the stents were patent at the end of the procedure. Immediate hemostasis was achieved in the six hemorrhagic cases. Immediate transient ischemic attacks were observed in two patients, and carotid sinus syndrome was observed in one patient. Post-treatment bleeding was observed in five patients in group 2 and no patients in group 1. Survival without bleeding was 251 days in group 1 and 35 days in group 2. During follow-up, three asymptomatic stent thromboses occurred at a mean of 58 days.. Covered stent placement is highly feasible and proved effective without major complications in CBS due to carotid axis bleeding.

Topics: Adult; Aged; Alloys; Blood Vessel Prosthesis Implantation; Carotid Artery Diseases; Female; Head and Neck Neoplasms; Humans; Male; Middle Aged; Polytetrafluoroethylene; Retrospective Studies; Risk Factors; Rupture, Spontaneous; Stents; Syndrome

Stent-assisted coiling is an accepted endovascular treatment (EVT) for wide-necked intracranial aneurysms. The Neuroform stent (Target Therapeutics, Fremont, Calif) is a flexible nitinol self-expandable stent that was designed to potentially overcome the limitations of balloon expandable coronary stents in the intracranial circulation. The aim of this study was to reenforce the use of this stent for EVT of wide-necked cerebral aneurysms.. Between March 2005 and March 2008, 24 patients harboring wide-necked cerebral aneurysms were treated with stent reconstruction of the aneurysm neck. Inclusion criteria restricted the group to adult patients with wide-necked intracranial aneurysms (ruptured and unruptured lesions). Immediate postprocedure angiography studies were performed to determine successful coil occlusion of the aneurysm as well as patency of the parent vessel. We assessed the clinical history, aneurysm dimensions, and technical detail of the procedures, including any difficulties with stent placement and deployment, degree of aneurysm occlusion, and complications. Clinical outcome was assessed with the Glasgow Outcome Scale (GOS).. The stent was easily navigated and precisely positioned in 24 of 26 cases. However, technical difficulties occurred in 9 patients, including difficulties in crossing the stents interstice in 6 cases, inadvertent stent delivery (n = 1), and incapacity of stent delivery (n = 1) and incapacity of crossing the neck (n = 1). These latter 2 cases were classified as failures of the stent-assisted technique. A single procedural complication occurred, involving transient nonocclusive intrastent thrombus formation, which was treated uneventfully with abciximab. Seventeen patients experienced excellent clinical outcomes (GOS 5), with good outcomes (GOS 4) in 5 patients and a poor outcome (GOS 3) in 2 patients. There were no treatment-related deaths or neurologic complications (mean clinical follow-up, 12 months). Angiographic results consisted of 17 complete occlusions, 4 neck remnants, and 3 incomplete occlusions.. The Neuroform stent is very useful for EVT of wide-necked intracranial aneurysms because it is easy to navigate and to deploy accurately. In most cases, the stent can be deployed precisely, even in very tortuous carotid siphons. Although in some cases delivery and deployment was challenging, clinically significant complications were not observed.

Topics: Adult; Aged; Alloys; Aneurysm, Ruptured; Carotid Artery Diseases; Cerebral Angiography; Embolization, Therapeutic; Equipment Design; Female; Glasgow Outcome Scale; Humans; Intracranial Aneurysm; Male; Middle Aged; Stents; Tomography, X-Ray Computed; Treatment Outcome

Large, symptomatic aneurysms of the cavernous internal carotid artery (ICA) can be successfully treated by a combination of aneurysm coiling and occlusion of the parent vessel.. We describe the use of an Amplatzer (AGA medical corporation, Plymouth, MA, USA) detachable nitinol vascular plug to occlude the ICA in four patients with symptomatic cavernous ICA aneurysms.

Topics: Aged; Alloys; Aneurysm; Angioplasty; Carotid Artery Diseases; Carotid Artery, Internal; Cohort Studies; Embolization, Therapeutic; Female; Humans; Middle Aged; Radiography

Evaluation of the use of covered stents in treating pseudoaneurysms of the cervical and intracranial/extradural carotid artery and determination of the periprocedural and short- to mid-term complication rate.. 8 patients with 9 spontaneous dissecting aneurysms of the cervical carotid artery--5 of which were symptomatic--plus one patient with ofthalmoplegia due to an aneurysm of the cavernous carotid artery were studied. While the latter was treated with a PTFE-covered balloon-mounted stainless steel stent (Jostent/Graftmaster), a self-expanding PTFE-covered Nitonol Stent (Symbiot) was used in all other cases. Intervention was performed with local anesthesia. Aspirin and Clopidogrel were both used as antiplatelet drugs. Clinical signs and symptoms and vascular imaging with DS, MR, CT angiography and ultrasound were recorded during patient follow-up, with a mean follow-up period of 14.6 months (4 - 30).. We were able to treat 8 out of 10 aneurysms (80%) using covered stents. The aneurysms were immediately occluded and the associated stenoses of the parent vessel were eliminated. No clinically relevant complications occurred during the procedure or in the follow-up interval. In two cases, elongation of the carotid artery prevented the stent from being positioned over the aneurysm neck. These cases were shown to be stable with the use of antiplatelet drugs.. Covered stents can be used in the treatment of pseudoaneurysms of the carotid artery as an alternative to long-term antithrombotic medication or surgery. In our study treatment was effective (80%) and free of complications in the short- and mid-term follow-up. Possible indications, technique and the use of imaging modalities for patient follow-up are discussed.

Topics: Adult; Alloys; Angiography, Digital Subtraction; Angioplasty; Aortic Dissection; Aspirin; Carotid Artery Diseases; Carotid Artery, External; Cerebral Angiography; Clopidogrel; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Platelet Aggregation Inhibitors; Polytetrafluoroethylene; Stents; Ticlopidine; Time Factors; Tomography, X-Ray Computed; Treatment Outcome

The Neuroform stent is a self-expanding nitinol stent designed for use in wide-necked intracranial aneurysms. Heating and imaging artifacts were evaluated by using a porcine carotid artery aneurysm model in a 3T MR system. A suspended Neuroform stent was tested for deflection. No heating was measured, and no evidence of deflection of the stent was found. Imaging artifacts were minimal. MR imaging in patients with Neuroform stent-treated aneurysms is safe and feasible.

Topics: Alloys; Animals; Artifacts; Carotid Artery Diseases; Contraindications; Disease Models, Animal; Equipment Failure Analysis; Equipment Safety; Heating; Intracranial Aneurysm; Magnetic Resonance Imaging; Phantoms, Imaging; Stents; Swine

To evaluate different vein graft-coated stent systems in the endovascular treatment of experimental arteriovenous fistulae (AVF) in a canine model.. Bilateral carotid-to-external jugular vein AVF were created. Two balloon-expandable tantalum stents (Strecker stent), two self-expanding nitinol stents (Strecker stent), and one stainless-steel stent (Wallstent) were coated with autologous vein grafts and placed using a transfemoral approach. Angiography was performed immediately after stent placement and at week 1 and 3, as well as at months 3, 6, and 9. All stents were removed and underwent histologic examination.. Occlusion of the AVF succeeded with the Wallstent and both tantalum stents. The nitinol stents were misplaced, maintaining the AVF. One undersized tantalum stent and the Wallstent were occluded after 3 weeks. One nitinol stent was occluded at 3 months, whereas the two remaining stents were patent during the whole observation period. No inflammatory tissue response was seen, and no host-versus-graft reaction was present.. Preparation and implantation of vein graft-coated stents, especially in the case of self-expanding stent systems, is cumbersome. This restricts the common use of such a coating, which shows an excellent biocompatibility. Vein graft-coated stents might be of use in infected endangered vessels.

Topics: Alloys; Anastomosis, Surgical; Animals; Arteriovenous Fistula; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Carotid Artery Diseases; Carotid Artery, Common; Dogs; Jugular Veins; Prosthesis Design; Radiography; Stainless Steel; Stents; Tantalum; Time Factors