缬沙坦涂层支架对支架术后再狭窄中胶原沉积的影响

目的评价缬沙坦涂层支架对支架置入后新生内膜中胶原沉积的影响及其预防支架内再狭窄的可行性。方法18只新西兰大白兔分为裸支架组,载体涂层支架组,缬沙坦涂层支架组3组。采用多层涂布技术制备缬沙坦涂层支架和载体涂层支架。分别将裸支架、载体涂层支架及缬沙坦涂层支架置入兔腹主动脉。术前、术后及支架置入3个月后分别行定量腹主动脉造影(QCA)测量血管直径。3个月后处死实验兔,分别测定3组支架血管段的管腔面积,内外弹力膜围绕面积,新生内膜面积及最大内膜厚度并做比较。将支架血管段进行MASSON染色,观察胶原沉积情况,天狼星红-苦味酸染色进一步观察胶原的类型。结果裸支架组(n=8),载体涂层支架组(n=8),缬沙坦涂层支架组(n=10),QCA测量的术前、术后及3个月后腹主动脉直径相似。缬沙坦组管腔面积最大,新生内膜面积最小,裸支架组、载体涂层支架组、缬沙坦涂层支架组平均管腔面积分别为(4345548±125822)μm2,(4302061±167952)μm2,(5016269±207934)μm2,平均新生内膜面积分别为(1119635±163503)μm2,(1135636±136555)μm2,(441577±74099)μm2,平均最大内膜厚度分别为(240±30)μm,(192±21)μm,(116±12)μm。MASSON染色可见新生内膜中主要是胶原沉积,天狼星红-苦味酸染色发现胶原沉积主要为Ⅲ型胶原,间或有Ⅰ型胶原。结论缬沙坦涂层支架主要是通过抑制胶原沉积抑制支架置入后血管内膜增生发挥其防治支架内再狭窄作用的。

Valsartan eluting-stents inhibited neointimal hyperplasia by decreasing collagen deposition in rabbits

OBJECTIVE: To assess the effect of valsartan eluting-stents on restenosis and collagen deposition in neointima hyperplasia in rabbits. METHODS: Valsartan eluting-stents and the carrier eluting-stents were made with patented multi-layers coating techniques. Bare stents (n = 8), carrier eluting-stents (n = 8) and valsartan eluting-stents (n = 10) were implanted into rabbit abdominal aortas, respectively. Quantitive angiography (QA) was performed before, immediately post and 3 months after stents implantations to determine the diameter of aortas. Rabbits were killed 3 months post stents implantation and the cross sections of the stented vessels were analyzed for neointimal formation: luminal area (LA), neointimal area (NIA), inner elastic lumina area (IELA), the maximal inner-membrane thickness (MIT) and percent stenosis. MASSON and picrosirius red staining were performed to observe the collagen deposition in neointima analyzed. RESULTS: The mean aortic diameters measured by QA at different time points were similar between the groups. LA was significantly larger (5 016 269 microm(2) +/- 207,934 microm(2) vs. 4,345,548 microm(2) +/- 125,822 microm(2) and 4,302,061 microm(2) +/- 167,952 microm(2), P < 0.01 vs. valsartan stents) while NIA (441,577 microm(2) +/- 74,099 microm(2) vs. 1,119,635 microm(2) +/- 163,503 microm(2) and 1,135,636 microm(2) +/- 136,555 microm(2)) and MIT (116 microm +/- 12 microm vs. 240 microm +/- 30 microm and 192 microm +/- 21 microm) as well as percent stenosis (8% +/- 2% vs. 20% +/- 2% and 21% +/- 2%) were significantly reduced in valsartan eluting-stents group compared to bare and carrier stents groups. MASSON and picrosirius red staining revealed rich type III collagen deposition in neointima and spare type I collagen patched around stents struts in bare and carrier stents groups and collagen deposition was rarely seen in neointima and stents struts in valsartan eluting-stents group. CONCLUSION: Valsartan eluting-stents inhibited neointimal hyperplasia by decreasing collagen deposition.