Experimental Evaluation of a New Single Wire Tantalum Coil Coronary Stent (Wiktor-iª)

To improve scaffolding properties, a new more densely woven Wiktor stent, the Wiktor-iª stent, was developed. Although the metal coverage remains still low compared to other stents, increased metal/vessel area raises the concern of increased thrombogenicity and neointimal hyperplasia. In this study we evaluated the Wiktor-i stent in a porcine peripheral and coronary model and compared the thrombogenicity and neointimal hyperplasia with the Wiktor-GX coronary stent. In a first study, a Wiktor-i and a Wiktor-GX coronary stent were implanted symmetrically in a preselected side branch of the right and left iliac artery of 10 healthy pigs. Quantitative vessel analysis showed comparable data before, immediately after and at follow-up. Hyperplasia measured by morphometry was also comparable in both groups (Wiktor-GX: 1.43 mm2 vs. Wiktor-i: 1.17 mm2, NS). Also, area stenosis was very similar (Wiktor-GX: 32% vs. Wiktor-i: 29%, NS). In a second study, 20 Wiktor (Wiktor-i: n=10, Wiktor-GX: n=10) coronary stents were implanted in the right coronary artery of 20 healthy pigs. Quantitative coronary analysis before, immediately after and at follow-up was comparable in both stents. The hyperplasia measured morphometrically was also comparable in both stents. (Wiktor-GX: 1.51 +/- 0.47 mm2 vs. Wiktor-i: 1.46 +/- 0.66 mm2, NS). Also the area stenosis was not significantly different (Wiktor-GX: 31% vs. Wiktor-i: 35%). In conclusion, this study shows that the increased metal/vessel area of the Wiktor-i stent does not result in an increased neointimal hyperplasia. Both stents show to be very biocompatible when implanted in porcine coronary and peripheral vessels.