Angiographic follow-up and clinical experience with the flexible Tantalum Cordis stent

Biological characteristics of the MG-63 human osteosarcoma cells on composite tantalum carbide/amorphous carbon films

Tantalum (Ta) is a promising metal for biomedical implants or implant coating for orthopedic and dental applications because of its excellent corrosion resistance, fracture toughness, and biocompatibility. This study synthesizes biocompatible tantalum carbide (TaC) and TaC/amorphous carbon (a-C) coatings with different carbon contents by using a twin-gun magnetron sputtering system to improve their biological properties and explore potential surgical implant or device applications. The carbon content in the deposited coatings was regulated by controlling the magnetron power ratio of the pure graphite and Ta cathodes. The deposited TaC and TaC/a-C coatings exhibited better cell viability of human osteosarcoma cell line MG-63 than the uncoated Ti and Ta-coated samples. Inverted optical and confocal imaging was used to demonstrate the cell adhesion, distribution, and proliferation of each sample at different time points during the whole culture period. The results show that the TaC/a-C coating, which contained two metastable phases (TaC and a-C), was more biocompatible with MG-63 cells compared to the pure Ta coating. This suggests that the TaC/a-C coatings exhibit a better biocompatible performance for MG-63 cells, and they may improve implant osseointegration in clinics.

Zotarolimus (ABT-578) eluting stents

Drug-eluting stents have revolutionized the field of interventional cardiology and have provided a significant innovation for preventing coronary artery restenosis. Polymer coatings that deliver anti-proliferative drugs to the vessel wall are key components of these revolutionary medical devices. This article focuses on the development of stents which elute the potent anti-proliferative agent, zotarolimus, from a synthetic phosphorylcholine-based polymer known for its biocompatible profile. Zotarolimus is the first drug developed specifically for local delivery from stents for the prevention of restenosis and has been tested extensively to support this indication. Clinical experience with the PC polymer is also extensive, since more than 120,000 patients have been implanted to date with stents containing this non-thrombogenic coating. This review provides background on pre-clinical studies with zotarolimus, on the development of the biocompatible PC polymer and on the clinical trials conducted using two stent platforms which deliver this drug to patients with coronary artery disease.

Tantalum as a buffer layer in diamond-like carbon coated artificial hip joints

The acid resistance of tantalum coated and uncoated human hip joint prostheses was studied with commercial CrCoMo acetabular cups. The samples were exposed to 10% HCl solution and the quantities of dissolved Cr, Co, and Mo were measured with proton-induced X-ray emission (PIXE). The absolute quantities were obtained with the use of Cr and Se solution standards. Tantalum coatings (thicknesses 4-6 microm) were prepared in vacuum with magnetron sputtering. Tantalum coating decreased the corrosion rate by a factor of 10(6). As a spinoff from recent wear tests on artificial hip joints it was shown that tantalum has excellent mechanical properties as an intermediate layer of diamond-like carbon (DLC) coatings. When tantalum was tested together with DLC on three metal-on-metal hip joint pairs in a hip simulator, no observable defects occurred during 15 million walking cycles with a periodic 50-300-kg load (Paul curve).

Multicenter evaluation of the phosphorylcholine-coated biodivYsio stent in short de novo coronary lesions: The SOPHOS study

AIMS: The BiodivYsio trade mark stent (Biocompatibles Ltd, Farnham, UK) is coated with a phosphorylcholine (PC)-containing copolymer to confer biocompatibility. The SOPHOS (Study Of PHosphorylcholine coating On Stents) study was designed to assess the safety and efficacy of this novel coronary stent and by indirect comparison to indicate equivalence with other formal stent studies. METHODS AND RESULTS: Patients with angina and a single short (#x2A7F;12 mm) de novo lesion in a native coronary artery of >/=2.75 mm diameter were included. A total of 425 patients were allocated in 24 centers. Clinical data were collected at one-, six- and nine-month follow-up. Angiography was performed before and after the stent implantation. In addition, in the first 200 patients (SOPHOS A) angiography was routinely performed at six months. The following 225 patients (SOPHOS B) were merely followed up clinically. The primary end-point of the study, the six-month MACE-rate (MACE = Major Adverse Cardiac Events) was 13.4% (two cardiac death; five Q-wave/nine non-Q-wave myocardial infarctions (MI); nine CABG and 32 target lesion revascularization (TLR), which is similar to the calculated 15% MACE-rate in comparable reference studies. Secondary end-points included among others restenosis at six months in the SOPHOS A population. The target vessel diameter was 2.98 +/- 0.48 mm. Minimal lumen diameter pre/post procedure and at follow-up was 1.00 +/- 0.32, 2.69 +/- 0.37, 1.91 +/- 0.71 mm, respectively. The binary restenosis rate (>/=50% diameter stenosis at follow-up) was 17.7%. CONCLUSION: The coronary BiodivYsio stent is safe and effective as a primary device for the treatment of native coronary artery lesions in patients with stable or unstable angina pectoris. Clinical and angiographic results are in the statistical range of equivalence with comparable studies with other current stents.

Preliminary experience with the V-flex plus coronary stent: immediate and one-month clinical outcome

Procedural and 1-month outcome data following implantation of the V-Flex Plus stent in our first 54 consecutive patients (35 male; mean age, 62 years) are described. Sixty-four stents were implanted for 60 mainly complex lesions; 48% were left anterior descending; 20%, circumflex; 27%, right coronary artery; and 5%, saphenous vein graft. The Indication for stenting was elective in half of the patients and for a suboptimal result or as a bailout procedure in the other half. The stents were deployed at a mean of 12 atm (range, 6-18) and postdilatated to a mean of 15 atm (range, 8-20). Pre- and postdilatation balloon sizes were 2.96 +/- 0.57 mm and 3.16 +/- 0.34 mm, respectively. The procedural success rate was 98%. There were no deaths or Q-wave myocardial infarctions. One patient suffered a non-Q-wave myocardial infarction and another developed a femoral false aneurysm. At 1-month follow-up, there were no additional events, in particular no revascularization procedures. Eighty-nine percent of patients were free of angina. Implantation of the V-Flex Plus stent is safe and effective with an excellent early success rate comparable to that of published randomized trials and registries of carefully selected patients.