INTRAARTERIAL BIOCOMPATIBILITY OF POLYETHYLENE TEREPHTHALATE SELF-EXPANDABLE STENTS IMPLANTED IN PORCINE PERIPHERAL ARTERIES

Rationale and Objectives. We tested deployment feasibility and intraar terial biocompatibility of polyethylene terephthalate (PET) self-expan dable vascular stents in a porcine peripheral artery model. Methods. T o assess the thrombogenicity and neointimal response to oversized PET self-expandable stents, we implanted 10 stents in porcine common iliac arteries, followed by a G-mm balloon inflation to 6 atm. Results. All pigs survived until the study termination 6 weeks after stent implant ation. Control angiography revealed stent closure in three pigs. Minim al stent luminal diameter (MSLD) was measured using a semiautomated ed ge detection algorithm. The difference in MSLD after stent implantatio n and at control after 6 weeks was not significant (4.9 +/- 0.5 mm --> 4.7 +/- 1.0 mm). Histopathologic examination showed signs of thrombot ic occlusion and revascularization in occluded stents. In patent stent s only a mild fibromuscular neointimal response was seen. Conclusion. PET self-expandable stents implanted in porcine iliac arteries are pos sibly thrombogenic but do not lead to a significant neointimal respons e.