肝素与阿魏酸钠对自体移植静脉内膜增生的影响

目的:采用袖套法改良大鼠自体移植静脉内膜增生模型,观察肝素与阿魏酸钠对移植静脉内膜增生的影响,以减少再狭窄率,为防治桥管再狭窄提供理论依据。方法:采用袖套法将大鼠自体颈外静脉移植入同侧颈总动脉,分别给予肝素(800 U/kg,ip,bid)、阿魏酸钠(100 mg.kg-1.d-1,iv)及两者联合用药至术后2周。应用病理形态学方法通过计算机图像分析,观察术后各组大鼠移植静脉内膜增生情况及药物对其影响;应用增殖细胞核抗原(PCNA)免疫组织化学方法检测移植静脉血管平滑肌细胞(VSMC)中PCNA表达的变化。结果:阿魏酸钠组和阿魏酸钠加肝素组与移植对照组相比,移植静脉内膜增生程度显著减轻(均P<0.05),PCNA阳性细胞比例显著下降(均P<0.05);肝素组与移植对照组相比,移植静脉内膜增生受到一定的抑制,但差异无统计学意义,肝素组移植静脉PCNA阳性细胞比例与移植对照组相比差异无统计学意义。结论:阿魏酸钠能显著抑制移植静脉内膜增生,而肝素无显著抑制作用;袖套法静脉移植模型设计科学,手术操作简便,成功率高。     

兔自体颈动脉移植于静脉后形态学及分子改变

目的以往的研究已证实动脉移植到静脉后，即使在高血脂状态下，也不发生粥样硬化，而是发生萎缩样改变，提示了血流动力学特别是切应力在动脉粥样斑块形成和血管重构中的作用。为探讨移植后动脉重构的机理，该文对移植动脉段进行了细胞分子生物学研究。方法建立动脉移植到静脉的新西兰白兔模型，6个时间点后取材，HE染色光镜下观察血管内、中膜厚度与面积；扫描电镜观察内皮变化，透射电镜观察超微结构改变；TUNEL方法观察细胞凋亡状况，RT－PCR检测基因表达水平。结果HE染色发现移植动脉在极低切应力状态下，随时间推移，除管壁发生“类静脉化”的萎缩样改变外，管腔面积先减小后增加；TUNEL结果显示移植动脉发生了细胞凋亡，而且凋亡先发于血管内膜细胞，进而过度到中层，最后累及外膜；通过弹力纤维和胶原纤维双染色证实，弹力纤维在整个过程中并未有显著数量改变，而胶原纤维却发生崩解，最终导致管壁萎缩；术后一周移植动脉的MMP2和MMP9表达明显增高，以后渐下降。结论低切应力作用于血管内膜层细胞致使其凋亡继而由内而外信号转递的过程，这构成了移植动脉发生萎缩样变的基础；胶原纤维的崩解在移植动脉萎缩样变过程中也发挥了重要作用，伴随着MMP表达的上凋。     

不同保存液对静脉移植物的保护作用研究

目的 探究搭桥过程中不同保存液对血管的近期及远期保护作用.方法 健康新西兰大耳兔48只,分4组.A组：GV液（维拉帕米＋硝酸甘油）组,B组：肝素化全血组,C组：罂粟碱组及D组：对照组（林格液＋肝素）.取兔颈外静脉,分别放置于不同保存液中,30 min后移植至颈内动脉.于7 d、14 d、28 d取出移植物,HE染色观察不同时期内皮增厚及中膜增生情况,计算I/M值.同时取5只兔股静脉,粗细均匀,分为40段约0.5 cm长短静脉,分别放入1 ml不同保存液中,30 min后取出静脉,Elisa法测量1 ml保存液中内皮素（ET-1）含量,HE染色观察短期保存后内皮细胞破坏情况.结果 14 d及28 d时各组比较,A组及B组血管内皮破坏及内膜增厚最轻,C组及D组内皮破坏及增生最为严重.第2周及第4周时A组及B组I/M值比较差异无统计学意义,与C组及D组比较差异有统计学意义（P＜0.05）.Elisa法测定ET-1含量,A组释放量较B组、C组、D组均明显降低（P＜0.01）,A组及B组短期保存后的血管内皮破坏情况较C组、D组要轻,内皮细胞覆盖率较高.结论 GV保存液及肝素化全血保存液可以更好地保护血管内膜,A组保存液较B、C、D组的ET-1释放量更少.     

大鼠自体移植静脉内膜增生模型的改进

目的改进大鼠自体移植静脉内膜增生模型。方法将36只SD大鼠随机分成实验组和对照组。实验组采用套管法将大鼠白体颈外静脉移植入同侧颈动脉系统。对照组采用吻合法行自体颈外静脉移植,术后均皮下注射肝素800U／kg,2次／d,共5d。观察术后不同时间点两组大鼠移植静脉通畅性、吻合口狭窄及内膜增生情况。结果实验组移植静脉自体移植静通畅性优于对照组,吻合口狭窄程度轻于对照组。结论实验组模型设计科学,操作简便,成功率高。     

人参皂苷Rb1抑制自体静脉移植物内膜平滑肌细胞增生的研究

目的:研究人参皂苷Rb1通过抑制自体静脉移植物增殖细胞核抗原(PCNA)的表达,进而抑制移植物内膜平滑肌细胞过度增生的作用。方法:45只新西兰大白兔随机分为实验组、模型组、对照组,每组15只。应用no-touch外科技术获取颈外静脉后,采用外翻连续缝合方法将颈外静脉吻合至颈总动脉,建立静脉移植桥的动物模型。4周后利用苏木精-伊红染色观察移植静脉血管内膜形态及厚度变化,RT-PCR检测静脉移植血管中PCNA mRNA的表达。结果:光镜下结果显示:移植4周后,实验组、模型组和对照组移植血管的内膜厚度分别为(41.57±2.43)、(73.76±7.83)和(11.38±0.71)μm,各组间差异有统计学意义(P<0.05),移植静脉内膜/中膜厚度比分别为(1.21±0.09)、(1.44±0.12)和(0.28±0.07),各组间差异有统计学意义(P<0.05);移植4周后的实验组、模型组和对照组PCNA mRNA相对含量比值分别是(0.942±0.004)、(0.756±0.003)和(0.574±0.002),各组间差异有统计学意义(P<0.05)。结论:人参皂苷Rb1能够抑制移植血管PCNA mRNA的过度表达,进而有效减轻移植血管内膜增生导致的再狭窄,延长静脉血管桥的使用寿命。     

不同剂量的熊果酸对大鼠静脉桥再狭窄过程中细胞凋亡的影响

目的 研究不同剂量的熊果酸诱导大鼠静脉桥再狭窄过程中内膜和中膜细胞凋亡的作用。方法 SD大鼠60只,体重300～350 g,随机分成UA（熊果酸）0组、UA1组、UA2组和UA3组。将所有实验动物的右侧颈外静脉以套管法移植至右侧颈总动脉上。UA1组、UA2组和UA3组术后首日开始予以熊果酸灌胃,剂量分别为15 mg?kg-1?d-1、30 mg?kg-1?d-1和45 mg?kg-1?d-1,UA0组不予熊果酸干预。术后满第1周、第2周和第4周分三次取材,每次每组随机选取5只大鼠。每条静脉标本随机选取不同位置的切片共5张做TUNEL检测。计算凋亡细胞指数。将4组数据对比研究。结果 1周、2周、4周静脉桥内膜细胞凋亡指数： UA0组（22.0±4.1,18.6±2.8,8.4±3.6）%,UA1组（28.4±2.4,19.2±1.4,9.4±3.5）%,UA2组（35.2±1.7,25.6±2.7,11.6±2.7）%,UA3组（41.5±1.9,28.4±1.8,16.3±1.4）%。1周、2周、4周静脉桥中膜细胞凋亡指数： UA0组（4.0±2.2,2.6±1.5,2.0±0.7）%,UA1组（6.6±2.3,4.2±1.6,2.6±1.1）%,UA2组（7.8±3.7,4.4±2.1,3.4±1.1）%,UA3组（7.6±1.7,4.0±0.8,3.5±0.7）%。内膜细胞凋亡指数比较,时间效应的P＜0.05,组别效应的P＜0.05,交互效应的P＜0.05。中膜细胞凋亡指数比较,时间效应的P＜0.05,组别效应的P＞0.05,交互效应的P＞0.05。结论 熊果酸具有诱导大鼠静脉再狭窄的内膜细胞凋亡的作用,该作用随着熊果酸剂量的增大而加强;而熊果酸不具有诱导静脉桥中膜细胞凋亡的作用。     

Time-Dependent thickening of the intima in aortocoronary saphenous vein grafts: Clinicopathological analysis of 24 patients

Summary The present study was undertaken to investigate histological changes in aortocoronary saphenous vein grafts (SVGs) and the relationship between intimal thickening of the SVGs and the interval after grafting. The SVGs were divided into five groups according to the degree of intimal thickening and associated luminal narrowing: minimal thickening (0%–10% stenosis), slight thickening (11%–25% stenosis), slight-to-moderate thickening (26%–50% stenosis), moderate thickening (51%–75% stenosis), and severe thickening (76%–100% stenosis). SVGs showing minimal thickening had been implanted for 0–3 weeks, those with slight thickening for 2–13 weeks, those with slight-to-moderate thickening for 5–13 weeks, those with moderate thickening for 30–52 weeks, and those with severe thickening for 30–83 weeks. Thickening of the intima in SVGs (intimal hyperplasia) was time-dependent, and began as early as 2 weeks after the graft surgery. The change was diffuse and concentric, and observed from an aortic root to a coronary site. The major cell type involved in the intimal hyperplasia was the smooth muscle cell.This work was supported, in part, by Grants-in-Aid for Scientific Research A (1993, no. 05770125) and (1994, no. 06770130) from the Ministry of Education, Science, and Culture of Japan.     

Postoperative changes in angiographically normal saphenous vein coronary bypass grafts using intravascular ultrasound

 We examined the process of vessel wall thickening in angiographically normal saphenous vein grafts (SVGs) using intravascular ultrasound. Fifteen SVGs were studied in the early stage (within 1 month postoperatively) and 14 SVGs in the late stage (over 6 months postoperatively). Lumen cross-sectional area (CSA) and vessel CSA were measured. Vessel wall area (VWA) was calculated and %VWA was defined as VWA / vessel CSA. Vessel CSA, VWA, and %VWA were significantly larger in the late stage than in the early stage (28.8 vs 21.6 mm², 15.8 vs 5.3 mm², 55.7% vs 24.9%, respectively) and lumen CSA was smaller in the late stage (12.8 vs 16.2 mm²). VWA correlated with vessel CSA, but not with lumen CSA. The time course of %VWA showed that %VWA in the late stage was a plateau state. From these findings, we concluded that the wall thickening process in SVGs begins within 6 months postoperatively and is accompanied by compensatory vessel enlargement. Received: May 8, 2002 / Accepted: September 6, 2002 Present address Department of Internal Medicine and Therapeutics (A8), Osaka University, Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan Tel. +81-6-6879-3635; Fax +81-6-6879-3645 e-mail: higuchi-yaj@umin.ac.jp Correspondence to Y. Higuchi     

Percutaneous coronary intervention of a saphenous vein graft ostial stenosis in a patient with Bentall procedure

Composite graft replacement of the aortic root and coronary reimplantation with or without coronary artery bypass surgery is the standard treatment for a variety of aortic root pathologies. Previously, percutaneous coronary intervention of either reimplanted coronary arteries or left/right coronary artery through cabrol graft has been described in post-Bentall patients. We describe percutaneous coronary intervention of a saphenous vein graft ostial stenosis in a patient with previous Bentall procedure and a vein graft to right coronary artery, which was complex and challenging.     

移植静脉外膜增生与兔血管再狭窄的相关性

目的 探讨冠状动脉旁路移植术后移植静脉外膜增生与血管再狭窄的相关性.方法 构建20例兔颈动脉旁路移植模型,术后当日行血管彩色多普勒检查,检测移植静脉的通畅性.术后30 d,取出移植静脉,组织病理标本切片、HE染色,测量外膜面积和管腔面积.用统计软件分析外膜面积与管腔面积的相关性.结果 术后当日,血管多普勒证明,所有20例模型移植静脉全部通畅.统计软件分析结果显示,移植静脉外膜面积与管腔面积成直线关系.结论 移植静脉外膜增生与血管管腔再狭窄有相关性.移植静脉外膜增生越重,管腔越狭窄.     

Immunohistochemical phenotypic alterations of rabbit autologous vein grafts implanted under arterial circulation with or without poor distal runoff-implications of vein graft remodeling

Although intimal hyperplasia is a major cause limiting the long-term patency of the vein grafts, its precise mechanisms, including the effect of poor runoff, has not yet been well characterized. We thus designed the present study to try to determine the effect of poor runoff arterial flow to the phenotypic alterations of the graft wall by immnohistochemistry using anti-intermediate filaments (alpha-SM actin, desmin, and vimentin) and anti-myosin heavy chain (SM1, SM2, and SMemb) specific antibodies. Vein grafts implanted under the poor runoff hind limb of rabbits showed enhanced intimal hyperplasia, however, no apparent difference in the cytoskeleton expression, including intermediate filaments and MHC, between two groups until 4 weeks. Interestingly, six of eight vein grafts at 2 weeks after implantation in both groups showed the accumulations of perivascular fibroblast-like phenotype (negative for SM1, alpha-SM actin, and desmin) in some parts of the outer neointima, whereas the inner neointima at 2 weeks and the whole neointima at 4 weeks were mainly occupied by a smooth muscle phenotype (positive for these three). Although the cellular origin of these cells is still unknown, these results suggest that the migration of non-muscle mesenchymal cells is involved in the neointima and thus may provide a clue for better understanding vein graft remodeling.     

RNA干扰沉默生存素基因表达对移植静脉内膜增生的影响

目的研究RNA干扰沉默生存素基因表达对移植静脉内膜增生的抑制作用。方法Wistar大鼠48只,建立自体静脉移植模型,术后随机分为对照组、空载体组s、hRNA对照组s、hRNA组,施加不同的处理因素,在移植12、周取材。比较内膜增生程度,半定量逆转录聚合酶链反应检测生存素基因的mRNA表达,Western blot检测生存素基因的蛋白产物表达,免疫组织化学法检测生存素及增殖细胞核抗原的表达,TUNEL法检测血管平滑肌细胞凋亡的变化。结果移植12、周内膜增生明显,局部转染靶向生存素基因的shRNA表达载体能够明显抑制内膜增生(P<0.05)。血管移植后,对照组及空载体组生存素的mRNA及蛋白产物表达显著增加,而shRNA组却显著减少(P<0.05),血管平滑肌细胞中增殖细胞核抗原表达减少,而TUNEL法阳性细胞明显增加。结论采用RNA干扰沉默生存素基因表达可显著抑制移植静脉的内膜增生,其作用机制可能是通过抑制生存素的基因及蛋白产物表达,从而抑制血管平滑肌细胞增殖,促进其凋亡而实现的。     

改良扩张方法对兔静脉移植物内皮细胞保护作用研究

目的:观察不同扩张方法对兔静脉移植物内皮细胞保护作用。方法:健康纯种新西兰兔72只,按扩张液(空白对照、罂粟碱和罂粟碱+维拉帕米)随机分为A组、B组、C组,每组24只。每组又分为4个亚组,用相同扩张液分别以30mmHg、40mmHg、50mmHg和100mmHg扩张2min,再保存30min。实验终了取静脉,测量扩张后单位面积血管内皮细胞死亡数目,测定内皮细胞功能。结果:相同扩张压力下,扩张后各组均有内皮细胞死亡,但C组明显低于A组和B组(P<0.01);各组内皮细胞功能均有降低,C组明显高于A组、B组(P<0.01)。A组和B组扩张压力在50mmHg时,内皮细胞损伤最轻;而C组以40mmHg最佳(P<0.01)。结论:新的扩张方法可减轻兔静脉移植物内皮细胞损伤。     

Applicability of distal protection for aortocoronary vein graft interventions in clinical practice.

Percutaneous revascularization of diseased saphenous vein grafts is associated with increased risk of adverse events, although the use of distal protection mitigates this to a significant extent. However, anatomic characteristics may preclude the use of such devices in a proportion of vein grafts intended for percutaneous treatment. We reviewed our consecutive experience of saphenous vein graft interventions from 1 May 2001 through 30 April 2002 to determine suitability for distal protection. Relevant angiographic characteristics included lesion within 5 mm of the ostium; lesion < 20 mm from the distal anastomosis; planned distal landing site of the occlusion balloon < 3 mm or > 6 mm in diameter; total occlusion of the vein graft; or lesion in a sequential vein graft distal to the first anastomosis. One hundred twenty-seven patients (140 procedures, 147 vein grafts) were treated. One or more of the angiographic exclusion criteria for a balloon occlusion protection system existed in 57% of grafts, while 42% had exclusions for a filter device. A large number of patients with vein graft disease intended for percutaneous treatment have anatomic exclusions to available distal protection technology.     

Immediate stent recoil in an anastomotic vein graft lesion treated by cutting balloon angioplasty

Saphenous vein graft (SVG) anastomotic lesions can have significant fibromuscular hyperplasia and may be resistant to balloon angioplasty alone. Stents have been used successfully to treat these lesions. There are no reports of immediate stent recoil following such treatment in the literature. We describe immediate and persistent stent recoil in an anastomotic SVG lesion even after initial and post-deployment complete balloon dilatation of the stent and its successful treatment by cutting balloon angioplasty.     

吡格列酮对高脂血症大鼠主动脉内皮细胞凋亡的作用

目的观察吡格列酮对高脂血症大鼠主动脉内皮细胞凋亡的影响,并探讨其可能的作用机制。方法清洁型SD大鼠26只,随机分为健康对照组(9只)、高脂饮食组(17只),高脂饮食组喂养12周后再随机分为模型组(8只)和吡格列酮组(9只),4周后,检测各组血脂水平,通过免疫组织化学法检测主动脉Bcl-2、Bax的表达,TUNEL染色法观察主动脉内皮细胞凋亡情况,计算细胞凋亡指数。结果 (1)高脂饮食组喂养12周后,血脂明显升高;给药4周后,与模型组比较,吡格列酮组TG、TC水平明显降低(P=0.000);(2)与健康对照组相比,模型组主动脉Bax蛋白表达明显增高(P=0.003),Bcl-2蛋白表达和Bcl-2/Bax比值明显降低(P=0.000);与模型组相比,吡格列酮组主动脉Bax蛋白表达明显降低(P=0.000),Bcl-2蛋白表达(P=0.001)和Bcl-2/Bax比值明显升高(P=0.000),且吡格列酮组主动脉内皮细胞凋亡指数较模型组明显降低,差异有统计学意义(17.5633±7.0584比6.0475±2.2370,P=0.000)。结论吡格列酮可改善高脂血症大鼠血脂水平,调节凋亡蛋白表达,减少主动脉内皮细胞凋亡。     

局部应用没食子儿茶素-3-没食子酸抑制移植静脉内膜增生

目的探讨局部应用没食子儿茶素-3-没食子酸对移植静脉内膜增生的抑制作用及其发生机制。方法应用异硫氰酸荧光素荧光标记技术和高效液相色谱法体外定性和定量测定血管对没食子儿茶素-3-没食子酸的吸收情况。日本大耳白兔20只,随机分为没食子儿茶素-3-没食子酸处理组和对照组(n=10)。建立兔颈外静脉与颈内动脉间置移植模型,移植前没食子儿茶素-3-没食子酸处理组血管在0.1 g/L没食子儿茶素-3-没食子酸中常温保存1 h,而对照组血管保存在生理盐水中。组织学方法测定移植三周后移植静脉血管新生内膜厚度、内膜中膜厚度比,原位DNA断裂位点的3′-羟基末端标记、Ki67免疫组织化学染色测定新生内膜阳性细胞百分比。结果0.1g/L没食子儿茶素-3-没食子酸中保存1 h2、h4、h,静脉血管的吸收量分别为2.9±0.9 mg/g、5.8±2.1 mg/g和8.0±2.3 mg/g,分布在血管壁全层。两组移植血管术后3周的通畅率均为90%(9/10)。移植术后3周没食子儿茶素-3-没食子酸处理组较对照组内膜厚度(41.1±13.6μm比89.9±48.3μm,P<0.01)及内膜/中膜厚度比(0.40±0.18比0.77±0.31,P<0.05)均显著降低,新生内膜Ki67阳性染色平滑肌细胞百分比也显著下降(22.4%±8.6%比8.8%±2.4%,P<0.05),而凋亡细胞百分比(0.40%±0.55%比0.60%±0.89%,P>0.05)无明显变化。结论局部应用没食子儿茶素-3-没食子酸能够抑制移植静脉内膜增生,可能与其抑制内膜平滑肌细胞增殖有关。     

Distal embolization at the site of a stenotic distal anastomosis of a saphenous vein graft,leading to dye entrapment

This case report describes the entrapment of contrast media after recanalization of a recently occluded saphenous vein graft with balloon predilation, thrombectomy and stent implantation. Recanalization of the respective coronary artery was performed, and the entrapped contrast media within the saphenous vein graft progressed to the left circumflex artery. (Int J Cardiovasc Intervent 2003; 5: 84-87)