Flueckiger Annina, Strahm Yvonne, Billinger Michael, Meier Pascal, Mettler Daniel, Studer Urs, Schaffner Thomas, Hess Otto M
Swiss Cardiovascular Center, University Hospital, Bern, Switzerland.
J Invasive Cardiol. 2009 Mar;21(3):128-32.
Polymer as carrier substance for drugeluting stents (DES) has been accused of inducing inflammation and hypersensitivity reactions leading to restenosis and stent thrombosis. Thus, a new paclitaxel-eluting stent (PES) with aminoparylene as a carrier substance is tested in the present study.
In 10 pigs, stents were implanted in the epicardial coronary arteries: 1) bare-metal stents (BMS, control stent); 2) cobalt-chromium stents (CCS); and 3) PES. Stent length was 15 mm, and diameter was 3 mm. The animals were restudied after 6 weeks. Quantitative coronary angiography was performed at baseline and follow up. Minimum luminal diameter (MLD) and late loss were calculated in all animals. Histologic vessel lumen, intimal proliferation and restenosis were determined by morphometry. Disruption of the lamina elastica interna (LEI) and inflammatory reactions were assessed by histology.
The MLD at baseline was 2.83 +/- 0.28 mm, and at follow up it was 2.29 +/- 0.44 (p < 0.05; n = 30). Late loss and angiographic restenosis were smallest in the CCS and largest in the PES (ns). Neointimal proliferation was similar for all 3 stents, ranging between 1.38 and 1.64 mm(2) (ns). There was a significant correlation between disruption of the LEI and inflammatory reactions.
PTs with aminoparylene as a carrier substance show similar late loss and angiographic restenosis to that of BM and CCS. The incidence of inflammatory reactions (35% of all histologic sections) is similar in all stents, but highest in PES. The mechanism of this reaction is unclear, but may be either due to the drug itself, the disruption of the LEI or to a hypersensitivity reaction.
聚合物作为药物洗脱支架（DES）的载体物质，被指责会引发炎症和超敏反应，导致再狭窄和支架血栓形成。因此，本研究对一种以氨基聚对二甲苯为载体物质的新型紫杉醇洗脱支架（PES）进行了测试。
在10头猪的冠状动脉心外膜植入支架：1）裸金属支架（BMS，对照支架）；2）钴铬合金支架（CCS）；3）PES。支架长度为15毫米，直径为3毫米。6周后对动物进行再次研究。在基线和随访时进行定量冠状动脉造影。计算所有动物的最小管腔直径（MLD）和晚期管腔丢失。通过形态学测定组织学血管腔、内膜增生和再狭窄。通过组织学评估内弹力膜（LEI）的破坏和炎症反应。
基线时MLD为2.83±0.28毫米，随访时为2.29±0.44（p<0.05；n = 30）。晚期管腔丢失和血管造影再狭窄在CCS中最小，在PES中最大（无显著性差异）。所有3种支架的新生内膜增生相似，范围在1.38至1.64平方毫米之间（无显著性差异）。LEI破坏与炎症反应之间存在显著相关性。
以氨基聚对二甲苯为载体物质的PTs显示出与BM和CCS相似的晚期管腔丢失和血管造影再狭窄。所有支架的炎症反应发生率（占所有组织学切片的35%）相似，但在PES中最高。这种反应的机制尚不清楚，但可能是由于药物本身、LEI的破坏或超敏反应。
