Development of a New Hybrid Biodegradable Drug-Eluting Stent for the Treatment of Peripheral Artery Disease

Abstract

This study aimed to develop a new biodegradable stent for peripheral artery disease (PAD) that could provide sufficient radial force to maintain long-term patency and flexibility. All self-expandable hybrid biodegradable stents were designed by using a knitting structure composed of poly-L-lactic acid (PLLA) and nitinol. Four different types of stents were implanted in 20 iliac arteries in 10 mini pigs as follows: a bare-metal stent (BMS) (group 1, n=5), a drug-free hybrid stent (group 2, n=5), a 50% (50: 100, w/w) paclitaxel (PTX)/poly-lactide-co-glycolic acid (PLGA; fast PTX-releasing form) hybrid stent (group 3, n=5), and a 30% (30: 100, w/w) PTX/PLGA (slow PTX-releasing form) hybrid stent (group 4, n=5). We performed follow-up angiography and intravascular ultrasonography (IVUS) at 4 and 8 weeks. In a comparison of groups 1, 2, 3, and 4, less diameter stenosis was observed in the angiographic analysis for group 4 at the 4-week follow-up (19.0% ± 12.7% versus 39.3% ± 18.1% versus 46.8% ± 38.0% versus 4.8% ± 4.2%, resp.; p=0.032). IVUS findings further suggested that the neointima of the patients in group 4 tended to be lesser than those of the others. Our new biodegradable 30% PTX/PLGA (slow-releasing form) stent showed more favorable results for patency than the other stent types.