雷帕酶素和巴曲酶复合药物涂层支架预防支架内再狭窄的实验研究

目的评价裸支架、巴曲酶支架、雷帕酶素支架、雷帕酶素和巴曲酶复合药物涂层支架（rapamycin-batroxobin eluting stent,RBES）抑制内膜增生的作用以及预防支架内再狭窄的效果。方法采用微喷法制备雷帕酶素和巴曲酶复合药物涂层支架,将裸支架、巴曲酶支架和雷帕酶素支架做为对照,复合药物组减少术后服用氯吡格雷的剂量和时间。于支架置入后3、7、28d截取支架段血管连同邻近的近端正常血管段,通过病理组织学分析和聚合酶链反应技术检测支架局部内膜增生情况。结果复合药物支架、雷帕酶素支架在再狭窄率、冠脉狭窄程度、管腔面积、新生内膜面积方面与裸支架组、巴曲酶支架组有显著差异（P<0.05）。复合药物支架组与雷帕酶素组在再狭窄率、冠脉狭窄程度、管腔面积、新生内膜面积方面无显著差异。裸支架组、巴曲酶支架组在再狭窄率、冠脉狭窄程度、管腔面积、新生内膜面积方面无显著差异。正常血管段在各个时间段增殖细胞核抗原（PCNA）mRNA均呈现无明显差异的低表达。裸支架、巴曲酶支架、雷帕酶素支架和复合药物支架置入后3d局部血管壁PCNA mRNA即呈现高表达,裸支架、巴曲酶支架显著高于正常血管段。雷帕酶素支架和复合药物支架略高于正常血管段,显著低于裸支架、巴曲酶支架,巴曲酶支架略低于裸支架;复合支架略低于雷帕酶素支架。结论复合药物支架置入可在一定程度上抑制内膜的增生反应,预防支架内再狭窄。     

葛根素对大鼠主动脉球囊损伤后血小板活化及凝血酶受体表达的影响

目的研究球囊损伤后血管内膜增生的过程、血小板活化水平、凝血酶受体mRNA的变化及葛根素的影响。方法将72只雄性W istar大鼠随机分为对照组、手术组和葛根素治疗组,分别在术后3、7、14和28 d通过组织学检查、放射免疫法和逆转录聚合酶链反应技术检测内膜增生的情况、血小板表面GMP-140的数目、凝血酶受体mRNA的水平及葛根素〔50 mg/(kg.d)〕腹腔注射对它们的影响。结果①凝血酶受体mRNA在正常血管组织表达极弱,球囊损伤术后3 d已显著增加,术后14 d达峰值,术后28 d开始下降。②GMP-140于术后3 d明显升高,术后7 d开始下降。③术后3 d已有增殖的血管平滑肌细胞移行至内膜层;术后7 d内膜开始增生;术后14 d血管平滑肌细胞的增殖及内膜增生更为明显;术后28 d血管平滑肌细胞的增殖明显减弱,细胞外基质增加,内膜继续增生。④使用葛根素后血小板表面GMP-140的数目减少,血管平滑肌细胞的增殖减弱,但凝血酶受体mRNA表达及内膜增生程度未见明显变化。结论血管内皮损伤后内膜增生的过程中血小板活化、凝血酶受体mRNA表达增加,葛根素抑制血小板的活化及血管平滑肌细胞的增殖,但对凝血酶受体mRNA的表达及内膜增生的程度无明显影响。     

犬冠状动脉支架植入术后细胞凋亡及凋亡相关基因蛋白表达的变化

目的观察犬冠状动脉支架植入术后血管内膜凋亡及凋亡相关基因蛋白表达的动态变化.方法15只犬进行冠状动脉左回旋支支架植入术,前降支相应血管作为对照,分别于术后1周、4周和12周处死,进行病理学检查、TUNEL法和透射电镜检测凋亡细胞、PCNA和Bcl-xl免疫组织化学染色以及Bcl-xl蛋白质印迹杂交.结果支架植入术后1～12周内膜面积持续增加;正常血管未见凋亡细胞和PCNA阳性细胞,术后1周内膜中凋亡细胞阳性率和PCNA阳性细胞率均达高峰,术后4周和12周不断降低,但凋亡细胞阳性率在各时间段均低于PCNA阳性细胞率;Bcl-xl免疫组织化学染色和蛋白印迹杂交均显示正常对照血管偶见表达,术后1周在内膜中表达增加,术后4周在内膜中大量表达,并可维持至12周.结论细胞凋亡相对不足可能是支架植入术后再狭窄形成的一个原因,Bcl-xl在内膜中高表达可能是造成细胞凋亡相对不足的因素之一.     

新型血管内可吸收镁合金支架的实验研究

目的评估自行设计制作的新型血管内可吸收镁合金支架的生物相容性、有效性和安全性。方法杂种犬35只,每只犬均于冠状动脉和股动脉置入可吸收镁合金支架1枚,分别于术后1、3、5 d和1、2、3、4周,每个时间点5只犬,复查冠状动脉和股动脉,血管造影后取材,分离支架段血管行组织病理观察及计算机图像分析,测量内弹力板面积、管腔面积、内膜增生面积及内膜增生面积百分比。结果 51枚支架成功置入35只犬的冠状动脉和股动脉,各时间点冠状动脉及股动脉造影均证实管腔通畅,无狭窄病变,无血栓形成。组织病理显示,支架置入术后1、3、5 d无内膜增生,仍有支架残留;1周支架完全降解;2周开始出现内膜增生,3周至4周内膜增生相对明显。各时间点均未见明显炎性反应和血栓形成;术后2、3、4周,内膜增生面积分别为(0.04±0.03)mm~2,(0.10±0.03)mm~2,(0.15±0.04)mm~2;内膜增生面积百分比分别为(1.84±1.18)%,(3.72±1.12)%,(6.29±3.36)%,差异有统计学意义(P<0.05)。结论血管内可吸收镁合金支架具有良好的生物相容性,安全有效,易操作,再狭窄程度轻,临床应用前景好。     

冠状动脉损伤修复中Ⅲ型胶原的表达及其与血管平滑肌细胞增生的关系

目的探讨血管损伤修复中Ⅲ型胶原的表达规律及其与血管平滑肌细胞(VSMC)增生的关系.方法26只犬冠状动脉内置入过大钽丝支架建立再狭窄模型,分别于术后7d、14d和28d处死动物,用透射电镜及免疫组化染色技术观察新生内膜中Ⅲ型胶原表达和VSMC特征,并用图象处理技术对Ⅲ型胶原的染色密度作定量分析.结果支架置入后7d以VSMC移行增生为主,14d时VSMC增生达高峰并有较多胶原表达,28d时VSMC由合成型逐渐转变为收缩型并表达大量胶原,Ⅲ型胶原在不同时间阶段的表达量具有显著差异(P<0.05).结论Ⅲ型胶原可能在再狭窄形成的后期内膜增生中起重要作用.     

雷公藤内酯醇涂层支架对猪冠状动脉内皮结构和再狭窄的影响

目的观察雷公藤内酯醇涂层支架（triptolide）置入猪冠状动脉后,血管内膜增殖过程中NF-κB、ki67表达的变化,探讨该药物支架对血管内皮的影响。方法将8只猪进行冠状动脉支架置入术,将雷公藤内酯醇涂层支架和裸支架组对照,置入前降支、回旋支、右冠脉近端。术后12周处死动物,采用光镜观察内膜增生情况,扫描电镜观察内皮修复情况,免疫组织化学法检测平滑肌细胞NF-κB、ki67表达。结果术后12周,triptolide组血管内膜增生[(内膜厚度（0.12±0.05）mm]、内膜面积[（1.17±0.25）mm2]明显小于对照组[内膜厚度[（0.35±0.11）mm,P<0.01],内膜面积[（1.81±0.36）mm2,P<0.05];电镜显示血管内膜表面的内皮细胞较对照组分布更紧密,排列更整齐,覆盖更完整;药物组NF-κB、ki67表达量显著低于对照组。结论雷公藤内酯醇涂层支架可抑制猪冠状动脉平滑肌细胞增殖,有效控制局部炎性活动,抑制内膜增殖。     

大鼠胸主动脉内皮损伤后内膜增生及PDGF-BB、PCNA、P16表达的变化

目的研究大鼠血管内皮损伤后内膜增生情况及血小板衍生生长因子-BB(PDGF-BB)、增殖细胞核抗原(PCNA)和抑癌基因P16的表达变化过程。方法选用雄性SD大鼠24只,球囊剥脱大鼠胸主动脉内皮,并随机将大鼠分为术后2 d、7 d、14 d、28 d处死4个组,每组6只。摘除胸主动脉,通过组织学检查和免疫组化技术检测内膜增生情况、PDGF-BB、PCNA、P16表达的变化。结果内皮损伤后2 d无血管内膜增厚,7 d内膜开始增生,28 d血管平滑肌细胞(VSMC)的增殖减弱,但细胞外基质增加,内膜继续增生;PDGF-BB、PCNA的表达均于术后2 d开始升高,PCNA的表达在术后7 d达高峰,而PDGF-BB在术后14 d达到高峰,P16在术后各时间点的表达变化不显著。结论 PDGF-BB、PCNA和P16的表达变化规律为寻找有效控制再狭窄的药物提供了理论依据。     

涂层支架局部导人c-myc反义寡核苷酸的在体分布研究及对细胞凋亡的影响

目的以国产铂-铱合金支架明胶蛋白涂层为载体,吸附c-myc ASODN,观察c-myc A-SODN局部应用后药物在组织中的分布,探讨c-myc ASODN对细胞增殖和凋亡的影响,寻求防治再狭窄的有效途径.方法将携带羧基荧光素(FAM)标记c-myc ASODN的国产铂铱合金明胶蛋白涂层支架(550μg/支架)置入兔颈动脉(n=6),术后45min、2h、6h分别处死2只动物,取靶布.另取32只家兔,对照组置入明胶蛋白涂层支架,处理组置入明胶蛋白涂层支架携带c-myc ASODN(n约=16).术后7、14、30、90d(n约=4),取置入支架血管,行HE、Weigert弹力纤维及Masson三色胶原纤维染色.c-myc蛋白免疫组化染色及原位杂交,采用透射电镜和未端脱氧核苷酸转移酶介导的dUTP缺口末端标记法(TUNEL)检测细胞凋亡,计算机图像分析测量平均新生内膜厚度和新生内膜面积,免疫组化和原位杂交平均阳性光密度和阳性表达面积.结果给药后45min、2h、6h镜下观察药物主要分布于靶点血管的中膜,随后弥散至外膜.对照组和处理组术后7d各有一例不完全性血栓形成,所有支架置入血管段均有不同程度新生内膜增生,偶见炎症细胞浸润,无异物巨细胞聚集.随观察时间延长,两组平均新生内膜厚度与新生内膜面积呈持续增加趋势;新生内膜面积均较对照组小,(P均＜0.001).术后7、14d均未观察到VSMC凋亡,术后30d在新生内膜中观察到明显的细胞凋亡,90d时单位面积内凋亡细胞数显著高于30d.30d时透射电镜观察到典型的凋亡细胞.对照组新生内膜中c-myc蛋白免疫组化及原位杂交均为阳性,处理组术后7、14d为阴性,30、90d为弱阳性.结论在短时间的观察中,发现明胶蛋白涂层支架介导的局部给药简便、可行,且药物主要分布于靶点血管壁中.c-myc A-SODN在体导入后,从c-myc mRNA和蛋白水平,均可显著抑制c-myc原癌基因的表达,抑制VSMC增殖,诱导VSMC凋亡,可用于防治支架内再狭窄.     

新型生物全降解药物释放支架对小型实验猪冠状动脉内膜的影响

目的探讨由融入无定型磷酸钙纳米颗粒构建的新型生物全降解支架置入小型实验猪后对损伤血管内膜的影响。方法将10只正常小型实验猪随机分为实验组(即融入无定型磷酸钙纳米颗粒构建的新型生物全降解支架组,5只)和对照组(普通聚左旋乳酸支架组,5只),选取合适的冠状动脉随机置入1枚普通聚左旋乳酸支架或新型生物全降解支架。分别于术前和术后28 d取股动脉血采用免疫吸附法行C反应蛋白(CRP)浓度检测。支架置入术后4周所有实验动物行冠状动脉造影复查后,处死动物并取支架置入部位血管固定并行苏木精-伊红染色,观察炎性细胞及炎症积分、内膜增生情况、免疫组织化学核因子(NF)-κB与α-平滑肌肌动蛋白(α-SM-actin)分析。结果实验组与对照组实验动物术后对动物觅食、活动等一般情况无影响。免疫吸附法检测血液CRP浓度显示,两组术前与术后28 d比较差异均无统计学意义,术后两组CRP浓度比较差异无统计学意义。实验组支架置入部位血管炎症细胞(27.32±1.50比54.12±3.99,P<0.05)及炎症积分(1.04±0.17比2.08±0.23,P<0.05)均明显低于对照组。实验组内膜增生面积增加、管腔面积减少、面积狭窄百分比升高及支架置入部位α-SM-actin平均光密度值升高,但差异均无统计学意义。结论新型生物全降解支架具有良好的组织相容性,其于冠状动脉置入后支架部位炎症较普通生物降解支架明显降低,未引起血管平滑肌细胞过度增殖亦不会导致内膜明显增生。     

球囊损伤大鼠主动脉内皮后血小板活化及凝血酶受体表达的变化

目的 探讨经皮冠状动脉腔内成形术后再狭窄的发生机制。方法建立大鼠主动脉内皮球囊损伤模型，分别于术后3天、7天、14天和28天，通过组织学检查、放射免疫法和逆转录一聚合酶链反应技术检测主动脉球囊损伤后内膜增生的情况、血小板表面GMP-140数目和凝血酶受体mRNA表达的变化。结果凝血酶受体mRNA在正常血管组织的表达较弱，球囊损伤术后第3天已显著增加，术后第14天达峰值，术后第28天开始下降。GMP-140于术后第3天明显升高，术后第7天开始下降。内皮损伤术后第3天已有增殖的血管平滑肌细胞移行至内膜层；术后第7天内膜开始增生；术后第14天血管平滑肌细胞的增殖及内膜增生更为明显；术后第28天血管平滑肌细胞的增殖明显减弱，细胞外基质增加，内膜继续增生。结论血管内皮损伤内膜增生的过程中血小板活化．凝血酶受体mRNA表达增加。     

Long-term intracoronary stent placement: Arteriographic and histologic results after 7 years in a dog model

Prosthetic intracoronary stenting has become an important adjunct to balloon angioplasty in the percutaneous treatment of coronary artery disease. However, there are few reports of the long-term histologic consequences of stenting in the world literature. We report the arteriographic, histologic, and ultrastructural examination of a flexible tantalum wire coil stent implanted in the coronary artery of a dog for 7 years. The vessel was arteriographically patent without evidence of either stenosis or ectasia. The stent had been incorporated into the arterial wall, and was covered with a neointima of approximately 100 μm maximum thickness. There was necrosis of the tunica media adjacent to the stent but the inflammatory response was restricted to occasional macrophages in the neointima of the immediate vicinity of the stent wire. The endothelial cell layer was normal in its morphologic appearance. In summary, the flexible tantalum wire coil stent was well tolerated by the host blood vessel and demonstrated acceptable biocompatibility for the 7-year duration of its implantation in the normal dog coronary artery. © 1996 Wiley-Liss, Inc.     

Elevated matrix metalloproteinase expression after stent implantation is associated with restenosis

OBJECTIVE: Matrix metalloproteinases (MMPs) play a key role in intimal growth and is responsible for ventricular remodeling after stent implantation. However, little is known about the relationship between early MMPs expression post-stent implantation and follow-up restenosis. METHODS: We investigated the serial changes of serum MMP-9, MMP-2 and tissue inhibitor of metalloproteinase-1 (TIMP-1) in 16 control subjects with normal coronary angiography (control) and 40 patients before and on the 1st, 3rd and 7th day after uncomplicated stent implantation. Follow-up angiography was performed at 6 months after stent implantation. RESULTS: Serum MMP-2 level was higher in patients with restenosis on the 1st day post-stent implantation and returned to pre-operation level thereafter. Serum MMP-9 levels consistently increased in patients with restenosis up to 7th day post-stent implantation; MMP-9 levels in the 1st, 3rd and 7th day after stent implantation were positively correlated to the late loss index 6 months after stent implantation. CONCLUSIONS: Increased serum MMP-9 level is associated with increased risk of restenosis post-stent implantation.     

Scanning electron microscopic analysis of vessel wall reactions after coronary stenting

High restenosis rates are still a major factor limiting the use of minimal invasive coronary stenting. Tissue reactions to the implanted alloplastic endoprostheses are still barely understood. 18 coronary artery segments 32 hours up to 340 days after stent implantation of 16 patients were post-mortem investigated. The pathomorphological findings of the vessel wall after stent insertion were studied by scanning electron microscopy (SEM). Stent integration can be divided with intraindividual differences in three phases: In the acute phase (<6 weeks) the border between vascular lumen and arterial wall is constituted by a thin, multi-layered thrombus. During the time course of integration, increasing amounts of Smooth Muscle Cells (SMC) and extracellular matrix can be detected. No endothelial cells can be found in the implantation zone. In the intermediate phase (6 weeks to 12 weeks) the neointima consists of extracellular matrix and increasing numbers of SMC. The borderline between lumen and neointima is generated by SMC and extracellular matrix. Increasing amounts of endothelial cells are found on the luminal surface of the stent neointima. Complete reendothelization is first noted in the chronic phase three months after stenting. Matrix structures are increasing whereas the amount of SMC decreases. In all phases of stent incorporation, the alloplastic stent material is covered by a thin (few nanometer) proteinaceous layer.     

Preventive effect of an antiallergic drug,pemirolast potassium,on restenosis after stent placement: quantitative coronary angiography and intravascular ultrasound studies

OBJECTIVES: The preventive effect of pemirolast against restenosis after coronary stent placement was evaluated. METHODS: Eighty-four patients with 89 de novo lesions who underwent successful coronary stenting were assigned to the pemirolast group(40 patients, 45 lesions) and the control group(44 patients, 44 lesions). Administration of pemirolast(20 mg/day) was initiated from the next morning after stenting and continued for 6 months of follow-up. Quantitative coronary angiography was performed immediately after stenting and at follow-up. Angiographic restenosis was defined as diameter stenosis > or = 50% at follow-up. Intravascular ultrasound study conducted at follow-up angiography was used to measure vessel cross-sectional area(CSA), stent CSA, lumen CSA, neointima CSA(stent CSA--lumen CSA), and percentage neointima CSA(neointima CSA/stent CSA x 100%) at the minimal lumen site. RESULTS: There were no significant differences in baseline characteristics between the two groups. Restenosis rate was significantly lower in the pemirolast group than in the control group(15.0% vs 34.1% of patients, 13.3% vs 34.1% of lesions, p < 0.05, respectively). The intravascular ultrasound study at follow-up(36 lesions in the pemirolast group, 33 in the control group) found no significant differences in vessel CSA and stent CSA between the two groups(17.3 +/- 2.2 vs 16.8 +/- 2.4 mm2, 8.6 +/- 1.9 vs 8.4 +/- 1.7 mm2, respectively). However, lumen CSA was significantly larger in the pemirolast group than in the control group(5.5 +/- 1.3 vs 4.4 +/- 1.1 mm2, p < 0.05). Moreover, neointima CSA and percentage neointima CSA were significantly smaller in the pemirolast group(3.1 +/- 1.1 vs 4.0 +/- 1.2 mm2, p < 0.05 and 36.2 +/- 15.9% vs 47.4 +/- 15.6%, p < 0.01). CONCLUSIONS: Pemirolast has a preventive effect against restenosis after stent placement, possibly by inhibiting neointimal hyperplasia.     

Influence of stent design and deployment technique on neointima formation and vascular remodeling

A variety of different stent types is available for the treatment of coronary stenosis. However, in-stent restenosis remains the major limitation for the use of these devices. Intracoronary ultrasound (ICUS) in addition to coronary angiography provides precise measurements of coronary wall dimensions during stent implantation and of intimal hyperplasia during follow-up. The extent of coronary injury during stent implantation was shown to play an important role in neointima formation. It is characterized by endothelial exposure, intima laceration, and media permeation. Stent-induced coronary injury has been considered to depend on stent design and stent strut size with consecutive deep wall laceration. ICUS analysis showed a correlation between the stent design and the amount of neointimal tissue proliferation. The role of adventitial remodeling in the process of restenosis is discussed controversially. Post-procedural stent expansion may provoke adventitial remodeling. The stent design and stenting strategy determines the extent of peri- and post-procedural coronary injury. Post-procedural coronary morphologic changes and changes of the stent geometry depend upon the stent design. Beside further modifications as the use of drug-eluting stents the decrease of stent-related vessel injury should be an important criterion for the development of future stent design.     

Long-term effects of polymer-based, slow-release, sirolimus-eluting stents in a porcine coronary model

BACKGROUND: Stent-based delivery of sirolimus (SRL) has shown reduction in neointimal hyperplasia and restenosis. The purpose of this study was to evaluate the chronic vascular response and the expression of cell cycle regulators after SRL-eluting stent implantation in a porcine coronary model. METHODS: Forty-nine pigs underwent placement of 109 oversized stents (control, n=54, SRL (140 microg/cm(2)), n=55) in the coronary arteries with histologic analysis and Western blot (PCNA, p27(kip1), CD45, MCP-1, IL-2, IL-6, TNF-beta) at 3, 30, 90 or 180 days. RESULTS: At 3 days, the mean thrombus area was similar for control (0.38+/-0.19 mm(2)) and SRL (0.29+/-0.09 mm(2)) stents. After 30 days, the mean neointimal area was significantly less for the SRL (1.40+/-0.35 mm(2)) versus the control stents (2.94+/-1.28 mm(2), p<0.001). At 90 and 180 days, the mean neointimal area was similar for the SRL (3.03+/-0.92 and 3.34+/-0.99 mm(2)) as compared with control stents (3.45+/-1.09 and 3.65+/-1.23 mm(2)). Western blot analysis demonstrated an increased expression of p27(kip1) in the vessel wall at 90 days for the SRL versus control stents (p=0.05) but with increased levels of PCNA in the SRL as compared with control stents (p=0.003). CONCLUSION: SRL-eluting stents favorably modulate neointimal formation for 30 days in the porcine coronary model. Long-term inhibition of neointimal hyperplasia is not sustained presumably due to delayed cellular proliferation despite increased levels of the cyclin-dependent kinase p27(kip1) in the vessel wall.     

Evaluation of coronary remodeling after sirolimus-eluting stent implantation by serial three-dimensional intravascular ultrasound

This study evaluates the response of the coronary vessel wall to implantation of the sirolimus-eluting stent (SES), Bx-VELOCITY, by using serial intravascular ultrasound. SESs have a major impact on the inhibition of in-stent neointimal hyperplasia. However, changes in the vessel wall and behind stent struts in animal models and humans have not been evaluated after SES implantation. Thirty-four patients who received a SES (n = 24) or a Bx-VELOCITY bare stent (BS) (n = 10) for single de novo coronary lesions and had serial motorized pullback 3-dimensional intravascular ultrasound were included. Stent, lumen, and vessel volumes were similar in the 2 groups at baseline. At follow-up, significantly larger lumen and lower neointimal hyperplasia volumes (0.7 vs 33 mm(3), p = 0.001) were seen in the SES group compared with the BS group. There was no significant difference between SES and BS in either the vessel volume (+2.4% vs +0.7%, p = NS) or the plaque behind stent volume change (+3.4% vs +2.5%, p = NS) from after the procedure to late follow-up. The stent edges also showed no significant difference between postprocedural and follow-up measurements, either in patients receiving SESs or BSs. No stented or edge segment required redilatation in the SES group, whereas 2 patients underwent repeat percutaneous coronary angioplasty in the BS group. In the SES group, 1 patient (4%) showed late acquired incomplete stent apposition. Thus, the SES is effective in inhibiting neointimal hyperplasia without affecting vessel volume and plaque behind the stent.     

Long-term effects of novel biolimus eluting DEVAX AXXESS plus nitinol self-expanding stent in a porcine coronary model.

OBJECTIVE: The purpose of this study was to evaluate the long-term effects of the DEVAX AXXESS biolimus eluting stent (BES) in a porcine coronary model, compared with those of bare metal stent (BMS) and polymer only stent (POS) controls. BACKGROUND: Excessive neointimal growth has been identified as a major cause of late failure of percutaneous coronary interventions. The effect of drug eluting from self-expanding stents for prevention of neointimal hyperplasia has not been studied before. The DEVAX AXXESS is a self-expanding nickel titanium stent, coated with antiproliferative compound-biolimus. METHODS: Twenty juvenile farm swine, 25-35 kg in weight, 3-6 months in age were used. Each animal received a stent to the left anterior descending artery, left circumflex or right coronary arteries as permitted per anatomy. The chronic vascular response after BES implantation was compared with that after BMS and POS implantation at 28, 90, and 180 days follow-up. RESULTS: The 28-day outcome by quantitative coronary angiography (QCA) showed significant increase in minimal luminal diameter (MLD) in the BES (MLD: 2.90 +/- 0.97, 2.39 +/- 0.90, 1.59 +/- 0.91; P = 0.009) compared with BMS and POS, respectively. By histomorphometric analysis, there was also a corresponding significant reduction in neointimal tissue proliferation in the BES (average neointimal area: 2.78 +/- 0.07, 5.46 +/- 0.66, 8.42 +/- 0.85; P = 0.002) compared with that in BMS and POS controls, respectively at 28-days follow-up. At 90 and 180 days, the mean neointimal area was not significantly different between the BES and the controls. CONCLUSIONS: BES favorably modulates the neointimal tissue formation for 28 days, in the porcine coronary model. Long-term inhibition of neointimal hyperplasia is not sustained most likely because of the delayed cellular proliferation and inflammation in the vessel wall.     

冠状动脉小血管病变中药物球囊的应用进展

既往研究表明,冠状动脉小血管病变在植入药物洗脱支架后容易发生支架内再狭窄和支架内血栓,因此成为近年来冠状动脉介入领域的难题.药物涂层球囊(DCB)作为冠状动脉介入领域中的一种新兴技术,可在不植入支架的情况下将抗增殖药物快速和均匀地释放到血管壁,抑制新生内膜的过度增生.越来越多的研究表明DCB对冠状动脉小血管病变有较好的...