犬肺动脉支架置入的实验研究

目的通过支架置入的成功率及生物相容性的实验动物研究,对肺动脉支架置入的可行性进行评价。 方法成年杂种犬8只,随机分为2组,每组4只。全麻下采用介入技术在其右肺下叶动脉置入Cook Zliver 635自膨式血管支架。实验组1术前2天～术后12周使用抗凝药,实验组2术前2天～术后6周使用抗凝药。所有动物,术前及术后即刻、术后6周、12周行DSA检查;术后6周、12周行CT肺动脉造影;术前及术后6周、12周进行肺动脉压力、潮气量及血气分析测定,12周时将动物处死取标本。评价支架置入过程、术后影像学表现、标本的组织病理学改变,对技术成功率、支架内皮覆盖、支架置入后狭窄率和潮气量、血气分析等参数进行统计学处理。采用SPSS 13. 0软件包进行分析,测最数据采用配对t检验及Friedman检验方法进行分析。 结果8只实验动物均顺利置入血管支架于右肺动脉内,支架释放过程顺利,支架膨胀良好、位置满意。术后影像学检查8只动物支架均未见狭窄、移位、变形、断裂等改变,但CT肺动脉造影显示其中2例支架近端未能完全贴紧血管壁。肺动脉压、潮气量、血气分析检查未发现显著改变。4例支架完全内皮化,4例支架未能完全内皮化(所有未完全内皮化的支架皆为远端内皮化,近端未内皮化,1例内皮化约30%、2例内皮化约50%、1例内皮化约70%),支架远端较近端更易形成内皮化,内皮化程度与实验组无关。被支架覆盖开口的分支血管皆未堵塞,血管内皮绕过血管分支开口处生长。 结论自膨式血管支架可以顺利置入犬肺动脉,对呼吸功能、右心功能无显著影响。肺动脉的血管支架置入是安全可行的。     

Willis覆膜支架治疗犬颈内动脉虹吸段动脉瘤的影像学和组织病理学研究

目的建立一种犬颈动脉虹吸段(CS)动脉瘤模型,并观察12个月以测试新型Willis颅内覆膜支架系统的机械性能;评价植入支架在弯曲段血管内的组织学反应。方法通过外科手术方法建立12只犬24枚颈动脉直段侧壁囊性动脉瘤(A组),和12只犬12枚CS动脉瘤(B组)。每枚动脉瘤行1枚覆膜支架植入治疗。以血管造影方法评价支架植入即刻,1、3、6和12个月随访动脉瘤闭塞、支架内漏、支架成角、载瘤动脉是否通畅及再狭窄率等情况。支架段血管行光镜和扫描电镜检查,评价动脉瘤腔内血栓形成,内膜增生和内皮化情况。结果B组中,支架植入即刻血管造影显示2枚动脉瘤存在轻度内漏,3枚支架存在轻度成角现象;12个月时随访,内漏均消失,1支载瘤动脉发生闭塞,3支载瘤动脉有轻度狭窄(<50%)。A组中,1支载瘤动脉闭塞,2支载瘤动脉轻度狭窄(<50%)。电镜检查所有支架内均有新生内膜形成,动脉瘤腔内均充满血栓。B组动物,12个月时才完成完全内皮化过程,内皮细胞排列与血流动力学方向具有很强的相关性。结论应用Willis覆膜支架治疗犬CS动脉瘤方法学上可行。与直段血管相比,弯曲段血管内覆膜支架植入后,支架内皮化时间延长。     

主动脉半周覆膜支架生物相容性及封堵效果的实验研究

目的 探索自制主动脉半周覆膜支架置入犬主动脉后的组织相容性及对肾动脉开口的封堵效果.方法 选用15条健康杂种犬,自制主动脉半周覆膜支架规格为16 mm×60 mm、人工血管长度为4 cm.经股动脉置入半周覆膜支架,随机封堵左或右侧肾动脉,尔后行主动脉造影及增强CT检查明确主动脉血流情况及肾脏供血情况.术后1,4,8,12和16周,随机选取3条犬复查主动脉造影及增强CT,随后处死、获取主动脉标本,分别对正常腹主动脉、裸支架处腹主动脉、覆膜支架处腹主动脉进行光镜及电镜的观察.结果 15条犬均成功地置入主动脉半周覆膜支架,分别封堵7条右肾动脉及8条左肾动脉,其余主动脉分支未受累.术中未发生血管破裂.主动脉造影及CT复查显示支架无移位,封堵肾动脉无血供,主动脉及其他分支血流正常.术后16周正常腹主动脉、裸支架处腹主动脉、覆膜支架处腹主动脉内膜厚度分别为85.7 μm、943.1 μm及2481.2 μm,相应中膜厚度为1401.5 μm、615.1 μm及593.6 μm,封堵侧肾脏缩小.结论 自制主动脉半周覆膜支架的组织相容性及封堵效果良好.主动脉半周覆膜支架具有应用于临床病例的可行性.     

原位肝移植术后肝动脉狭窄的介入放射学治疗

目的 对肝移植术后肝动脉狭窄的早期诊断及介入治疗进行初步的探讨和分析。资料与方法 回顾性分析本院1998年9月至2004年1月进行的450例原位肝移植术后34例肝动脉狭窄、闭塞的诊断及介入治疗资料。对33例肝动脉狭窄的病例行球囊导管扩张治疗，3例扩张治疗无效的患者及1例球囊扩张后出现肝动脉内膜撕裂的患者行内支架置人治疗；1例肝动脉狭窄伴吻合口破裂出血的患者直接行内支架置入治疗。结果 30例肝动脉狭窄的介入治疗获得成功，4例患者介入治疗失败。治疗成功的病例术后预后良好，肝功能有明显改善。治疗失败的病例预后不良。结论 介入治疗方法对肝移植术后肝动脉狭窄的早期诊断及治疗具有较大的应用价值，肝动脉狭窄应首选球囊扩张治疗，必要时采用内支架置入治疗。     

颅内动脉瘤用纳米电纺覆膜支架初步实验研究

目的 动物实验研究评价新型颅内动脉瘤用纳米电纺覆膜支架的力学性能和生物相容性.方法 10只健康成年比格犬中共植入20枚纳米电纺覆膜支架,其中10枚0.10 mm丝径支架植入左侧锁骨下动脉(A组),10枚0.15 mm丝径支架植入右侧锁骨下动脉(B组).支架植入术后即刻和术后2、4、6周分别作血管造影随访.支架段血管作组织学病理检查,评价支架内皮化和内膜增生情况.结果 A组支架植入后即刻造影示7枚支架内漏,随访期间2枚支架内漏消失,5枚仍残留内漏;B组支架植入后即刻造影示1枚支架内漏,随访期间内漏消失,3枚支架发生轻度狭窄(狭窄程度＜50％).组织病理学检查显示,B组术后2周血管壁呈慢性炎性反应,术后4周支架内表面部分血管内皮化,术后6周支架内表面基本实现血管内皮化.结论 本实验研究初步证明纳米电纺覆膜支架治疗颅内动脉瘤的有效性和可行性,具有重要临床应用价值.但该支架尚处于初始研究阶段,有待进一步远期观察和研究.     

犬胸主动脉内分体式覆膜支架置入的实验研究

目的 评价分体式覆膜支架置于犬胸主动脉内的技术可行性及支架的生物相容性..方法 成年杂种犬12只,随机分为3组,每组4只.切开右侧股动脉,经犬右侧股动脉将分体式覆膜支架置于犬胸主动脉内,且使外层移植物的近端至少接近左锁骨下动脉开口的远端,观察支架释放的技术可行性.按照实验分组分别于术后4、8和12周血管造影复查分体式覆...     

颅内动脉支架动物模型的初步建立

目的在犬的颅内血管内置入支架,建立颅内支架的活体模型。材料与方法在行犬的血管造影后,将支架置入其基底动脉内。存活的动物被观察4周,复查造影后有计划地处死动物以获得置入支架的部分血管。结果12只犬行血管造影,其中6只犬的基底动脉成功置入6枚支架。随访观察后,成功地从6只犬颅内取出支架。结论建立颅内支架活体模型,为颅内动脉支架术后血管反应的进一步研究提供了一个可靠的技术平台。     

三种覆膜支架治疗犬颈动脉囊状动脉瘤的实验研究

目的 探讨颅内覆膜支架治疗犬颈动脉囊状动脉瘤的可行性、安全性和疗效。方法 采用外科手术方法在20只犬中建立犬颈动脉囊状动脉瘤模型36枚，应用血管内技术放置聚氨酯膜支架(PUM-SSS)、可膨胀聚四氟乙烯膜支架(ePTFEM-SSS)、生物膜支架(BM-SSS)各12枚，支架置人后即刻及术后2、4和12周分别进行血管造影随访，并进行组织病理学检查及统计学分析。结果PUM-SSS、ePTFE-SSS和BM-SSS的完全开放率分别为25．O％、41．7％和91．7％，PuM-SSS、ePTFE-SSS分别和BM-SSS比较有非常显著的差异。组织学分析表明，支架置放后2周BM-SSS内皮化开始，12周3种支架内皮化基本完成；所有治疗的动脉瘤瘤腔内均见血栓形成，载瘤动脉内膜增厚；支架附着处血管见不同程度的细胞变性；金属支架未见到腐蚀。结论 覆膜支架是一种新的简单、安全、有效的治疗犬颈动脉囊状动脉瘤的方法。生物膜支架具有更好的血液相容性和血管开通率，是一种较理想的覆膜支架。     

介入治疗肝移植术后肝动脉并发症的初步经验

目的总结采用介入方法治疗肝移植术后并发肝动脉狭窄及血栓形成的初步经验。方法对4例肝移植术后并发肝动脉狭窄或血栓形成的患者行球囊扩张、经动脉溶栓、内支架置入术。结果1例肝动脉狭窄的患者经球囊扩张后临床症状缓解;3例肝动脉血栓形成患者经动脉溶栓后即刻肝动脉血流得到恢复;1例患者溶栓后3d发生吻合口出血,置入带膜支架,症状缓解,1d后肝动脉再次闭塞,2周后行第2次肝移植。结论采用介入方法对肝移植术后并发肝动脉狭窄或血栓形成的患者进行治疗是可行的,但必须谨慎实施,以避免发生出血等并发症。     

冠状动脉造影及支架置入术在冠心病诊断与治疗的临床应用

目的　评价冠状动脉造影及支架置入术在冠心病诊断与治疗的临床应用价值。方法　对 40例 47支冠状动脉病变内置入 5 6只支架 ,其中置入前降支 2 9只 ,右冠状动脉 1 8只 ,左回旋支 9只。结果　 40例全部置入成功 ,置入后经冠状动脉造影证实狭窄消失 ,即刻效果良好 ,由术前狭窄 ( 88.9± 8.1 ) %减至术后残余狭窄 ( 5 .6± 5 .1 ) %,支架置入成功率 1 0 0 %。术后低血压反应 2例 ,血肿 3例。结论　冠状动脉造影及支架置入术是冠心病诊断与治疗的一种安全可靠、效果良好的介入性诊断治疗方法 ,值得临床广泛应用。     

动脉粥样硬化性缺血性肾病的血管内介入方法选择和疗效探讨

目的评价动脉粥样硬化性肾动脉狭窄血管内介入治疗的方法和临床疗效。方法28例肾动脉狭窄采用导引导管法(A组19例)和导丝交换法(B组9例)，行经皮肾动脉内支架成形术，共植入支架31枚(Palmaz支架22枚，Wallstent4枚，Symphony支架5枚)。随访6个月～1年，观察血压、血肌酐、抗高血压药用药情况，并与术前比较。结果两组肾动脉内支架成形术技术成功率为100％，B组中有2例患者术中发生肾动脉远端分支栓塞，两组共有4支血管发生再狭窄。结论导引导管法肾动脉内支架是动脉粥样硬化性肾动脉狭窄介入治疗首选方法；维护肾功能是该治疗的首要目的。     

应用覆膜支架治疗自发性外周动脉夹层9例

目的 探讨应用覆膜支架腔内隔绝自发性外周动脉夹层的安全性及有效性.方法 收集9例自发性外周动脉夹层患者,病变在髂动脉6例,锁骨下动脉3例.术前均行CTA检查,明确外周动脉夹层的部位和程度,预定覆膜支架.所有患者经Seldinger穿刺股动脉后进一步造影明确病变,依据造影结果植入覆膜支架.结果 9例患者中,病变在右侧髂总动脉3例,右侧髂外动脉l例,左侧髂总动脉2例,左侧锁骨下动脉3例.夹层长度0.9～3.3 cm,平均1.7 cm.动脉夹层起始部距靶血管开口距离0.5～5,6 cm,平均2.3 em.所有患者均成功植入覆膜支架,1例覆膜支架覆盖左侧非优势椎动脉,术中无明显并发症发生.随访3～32个月,平均18个月,所有患者均无相关并发症发生,彩色多普勒超声复查示支架通畅.结论 应用覆膜支架腔内隔绝自发性外周动脉夹层是一种安全有效的治疗方法.     

Assessment of a Polyester-Covered Nitinol Stent in the Canine Aorta and Iliac Arteries

Purpose: To evaluate the patency and healing characteristics of a woven polyester fabric-covered stent in the canine model. Methods: Twenty-four self-expanding covered stents were placed in the infrarenal aorta and bilateral common iliac arteries of eight dogs and evaluated at 1 (n = 2), 3 (n = 2), and 6 (n = 4) months. Stent assessment was done using angiography prior to euthanasia, and light and scanning electron microscopy. Results: Angiographically, just prior to euthanasia, 8 of 8 aortic and 14 of 16 iliac endovascular covered stents were patent. Histologically, the stented regions showed complete endothelialization 6 months after graft implantation. A neointima had formed inside the stented vessel regions resulting in complete encasement of the fabric-covered stent by 3 months after graft implantation. Medial compression with smooth muscle cell atrophy was present in all stented regions. Explanted stent wires, examined by scanning electron microscopy, showed pitting but no cracks or breakage. Conclusion: The covered stent demonstrated predictable healing and is effective in preventing stenosis in vessels 10.0 mm or greater in diameter but does not completely preclude stenosis in vessels 6.0 mm or less in diameter.     

A new polymer concept for coating of vascular stents using PTFEP (poly(bis(trifluoroethoxy)phosphazene) to reduce thrombogenicity and late in-stent stenosis

OBJECTIVES: We sought to evaluate the new polymer PTFEP (poly(bis(trifluoroethoxy)phosphazene) for (1) its ability to reduce thrombogenicity and late in-stent stenosis and (2) its effect on endothelialization in a rabbit iliac artery model. MATERIALS AND METHODS: Nanocoated ( approximately 50 nm) and bare stainless-steel stents were implanted bilaterally in the iliac arteries of 30 New Zealand White rabbits (1, 4, 8, 12, and 16 weeks follow-up) and evaluated by angiography, light, and scanning electron microscopy. RESULTS: Bilateral stent placement was successful in 27 of 30 rabbits. Thrombus depositions occurred in none of the 27 coated but in 4 of the 27 bare stents (P=0.037). A normal angiogram was obtained in 18 of 22 coated stents at risk for restenosis (follow-up >or=4 weeks) but only in 13 of 22 bare stents (P=0.023). Marked restenosis (luminal loss >30%) was found in 6 bare stents (P=0.011) but not in any coated stents. The neointima was 47.7-73.9 mum on coated and 66.9-115.2 mum on bare stents (statistically significant at 4, 8, and 16 weeks). Scanning electron microscopy detected full endothelialization in all stents from 4 weeks on (22 stents in both groups). CONCLUSION: PTFEP nanocoating successfully showed thromboresistance and reduced late in-stent stenosis. Endothelialization was equal in both stent types. Studies in more human-like models and human feasibility studies in human arteries are encouraged.     

食管恶性狭窄内支架治疗和良性狭窄球囊扩张后的随访评价

目的　评价食管恶性狭窄内支架治疗和良性狭窄球囊扩张后的长期随访疗效。方法92例食管狭窄做了内支架或球囊扩张 ,有较完整的随访资料。 5 9例恶性食管狭窄均置入了内支架 ,其中置入支架前后行放射治疗 (简称放疗 )和 (或 )化学药物治疗 (简称化疗 ) 3 7例 ,占 63 % ;3 3例良性食管狭窄做了单纯球囊扩张治疗。内支架置入类型 :国产镍钛记忆合金网孔支架 2 4例 ,带膜支架2 2例 ;国产GianturcoZ形支架 7例 ,带膜支架 4例 ;Ultreflex支架 2例。门诊行食管造影和内窥镜检查随访 78例 ,14例通过电话或信件随访。结果　本组病例经过 1～ 4 1个月的随访观察 ,仅 1例支架发生轻度移位 ,但仍能覆盖病变全长。食管恶性狭窄 17例死亡 ,术后生存时间 2～ 3 0个月 ,平均 8 2个月。死亡原因 :肿瘤多脏器转移 15例 ,心肌梗死 1例 ,其他原因引起死亡 1例。恶性食管狭窄内支架置入后再狭窄 11例 ,因食物在支架内阻塞 1例 ,发生食管 气管瘘 1例 ,因肿瘤组织生长发生狭窄 8例 ,因支架上端组织增生发生狭窄 1例。发生再狭窄的 11例均再次做了内支架置入或球囊扩张治疗。结论　中晚期食管癌内支架置入是解除吞咽困难有效的姑息治疗方法 ,应用带膜支架和同时行放疗、化疗可防止因肿瘤生长而发生再狭窄 ,延缓患者生命。球囊扩     

Late Stent Expansion and Neointimal Proliferation of Oversized Nitinol Stents in Peripheral Arteries

For peripheral endovascular intervention, self-expanding (SE) stents are commonly oversized in relation to target arteries to assure optimal wall apposition and prevent migration. However, the consequences of oversizing have not been well studied. The purpose of this study was to examine the effects of SE stent oversizing (OS) with respect to the kinetics of late stent expansion and the long-term histological effects of OS. Pairs of overlapped 8 × 28-mm Nitinol SE stents were implanted into the iliofemoral arteries of 14 Yucatan swine. Due to variations in target artery size, the stent-to-artery ratio ranged from 1.2:1 to 1.9:1. Lumen and stent diameters were assessed by quantitative angiography at the time of implantation. Following angiographic assessment at 6 months, stented arteries were perfusion-fixed, sectioned, and stained for histological analysis. Immediately following implantation, the stents were found to be expanded to a range of 4.7–7.1 mm, largely conforming to the diameter of the recipient target artery. The stents continued to expand over time, however, and all stents had enlarged to nearly their 8-mm nominal diameter by 6 months. The histological effects of OS were profound, with marked increases in injury and luminal area stenosis, including a statistically significant linear correlation between stent-to-artery ratio and area stenosis. In this experimental model of peripheral endovascular intervention, oversized Nitinol SE stents are constrained by their target artery diameter upon implantation but expand to their nominal diameter within 6 months. Severe OS (stent-to-artery ratio >1.4:1) results in a profound long-term histological response including exuberant neointimal proliferation and luminal stenosis.     

Radial force and wall apposition of balloon-expandable vascular stents in eccentric stenoses: an in vitro evaluation in a curved vessel model

PURPOSE: Important criteria for optimized stent implantation are high radial force and complete apposition of the stent itself. The aim of this study was to develop a simple method to assess these parameters under controlled experimental conditions and to compare vascular stents of different designs with regard to these parameters. MATERIALS AND METHODS: Five balloon-expandable stents of different designs (Jostent Flex, MAC stent, ML-Tristar, ML-Ultra, and S670) were tested. Fourteen stents of each type were implanted in a curved plastic vessel model (curve radius, 10 mm; lumen diameter, 3.5 mm) with use of a balloon inflation pressure of 12 atm. Part of the model was a nonflexible eccentric stenosis which was 2 mm or 8 mm in length. After stent implantation, a stenosis of 10%-70% was induced and radial force of the stent struts was measured at the site of the stenosis. The apposition of the stent to the vessel wall was imaged by high-resolution radiography. RESULTS: Analysis of variance showed significant differences of radial force between the tested stents (P <.001). The ML-Tristar and ML-Ultra stents had the highest radial force with maximum mean values of 687 cN and 846 cN at a stenosis of 70% in the model with the long stenosis. The radial force of the S670 stent was the lowest whereas the MAC stents showed an intermediate radial force. Radial force of the ML-Ultra stent was as much as 3.8 times higher than the force of the S670 stent (P <.001). Fifty percent of the ML-Tristar and ML-Ultra stents did not expand sufficiently to touch the vessel surface at the outer curvature. With an inflation pressure of 17 atm, complete apposition of these stents was achieved. The highest number of apposition irregularities was found in the S670 group (13 of 14 stents), whereas the MAC stents revealed the lowest number of irregular appositions (three of 14 stents). A significant correlation was found between the number of interconnecting struts and the number of irregular apposition events (P <.01). CONCLUSIONS: This model allows an accurate in vitro evaluation of different stent parameters, such as apposition to the vessel wall and radial force. None of the investigated stents showed optimal results with respect to both parameters. The apposition behavior was significantly influenced by the architecture of the stents.     

个体化全覆膜支架封堵食管-胃吻合口瘘、胸腔胃-气道瘘、化学灼伤后食管瘘

目的探讨个体化可取式覆膜支架,封堵食管-胃连接部吻合口瘘和胸腔胃-主支气管瘘及化学灼伤后食管瘘的治疗方法及临床价值。方法667例上消化道良、恶性病变支架植入病例中,食管-胃吻合口瘘63例,胸腔胃－气道瘘11例,化学灼伤后食管瘘17例。瘘口直径0．5～2cm。瘘口部位：食管－胃颈部吻合口瘘7例,食管－胃胸腔内吻合口瘘33例,食管－胃膈下吻合口瘘23例;胸腔胃－右主支气管瘘9例,胸腔胃－气管隆突瘘2例;化学灼伤后食管上段瘘3例,中段瘘9例,下段瘘5例。均在DSA透视下经口腔植入支架,依据残胃大小及瘘口位置,选定下端为大喇叭口径可取式覆膜支架63枚;气管-支气管分叉型全覆膜支架11枚;全覆硅胶膜长管状“Z”型支架18枚。结果63例食管-胃吻合口瘘及11例胸腔胃-气道瘘和17例化学灼伤后食管瘘,共植入支架92枚。支架植入后分别于2、7、12、17、22、30d,口服碘水DSA下透视检查,所有病例均堵瘘成功。支架取出无一例消化道出血、食管破裂、瘘口复发等并发症出现。结论设计个体化可取式覆膜支架,封堵食管-胃连接部吻合口瘘和胸腔胃-气道瘘及化学灼伤后食管瘘临床疗效肯定,具有临床推广应用价值。     

ViabahnTM自膨式覆膜支架腔内修复注射毒品所致股动脉假性动脉瘤9例

目的 初步探讨ViabahnTM自膨式覆膜支架腔内修复治疗注射毒品所致股动脉假性动脉瘤(PSA)的可行性、安全有效性.方法 回顾性分析2014年4月至2015年4月收治的9例注射毒品所致股动脉PSA患者临床资料,病变位于股总动脉6例,股浅动脉3例,均接受ViabahnTM自膨式覆膜支架腔内修复术.记录术中造影表现、植入支架尺寸和支架植入后即刻造影结果.术后随访观察患者症状改善、瘤腔修复效果及内漏、支架感染、支架内狭窄及断裂情况.支架植入前后均作抗感染治疗,术后对腹股沟区软组织感染区作清创及(或)引流术.结果 9例患者均成功植入ViabahnTM自膨式覆膜支架,技术均获成功,无死亡.所有患者术后即刻造影提示瘤腔完全修复,载瘤动脉远端通畅,无内漏发生.术后6、12个月随访时,所有患者均保肢成功,未出现间歇性跛行及肌肉萎缩、乏力.CTA复查显示无内漏,无支架感染、断裂及支架内狭窄发生.结论 在充分抗感染及局部清创引流条件下,ViabahnTM自膨式覆膜支架能迅速覆盖PSA瘤腔破口,挽救患者生命,其较好的柔顺性、贴附性和通过性减少了术后间歇性跛行及支架断裂、支架内狭窄发生率,有望成为注射毒品所致股动脉PSA患者血管重建方法之一.其远期疗效仍需进一步观察和论证.