恶性胆道梗阻金属支架堵塞后再次置入金属和塑料支架的比较

背景：在堵塞的支架中再次置入金属或塑料支架可解决支架的堵塞问题,然而关于支架间如何搭配组合将使患者受益更大却一直存在着争论。 目的：对比恶性胆道梗阻金属支架堵塞后再次在其内置入不同种类支架之间的临床效果。 方法：收集在南昌大学第二附属医院行经内镜胆道金属支架置入的,且在原支架堵塞后再次在其内置入另一支架的中、低位胆道恶性梗阻患者83例,并根据原支架与再次置入支架的不同搭配组合形式,将以上患者分为3组,即覆膜金属支架组、无覆膜金属支架组和塑料支架组。 结果与结论：在原金属支架堵塞后,再次置入覆膜金属支架的通畅时间显著长于塑料支架(P < 0.05);覆膜金属支架组的支架累计通畅时间显著长于无覆膜金属支架组(P < 0.05-0.01)。提示经内镜置入胆道金属支架治疗中、低位胆道恶性梗阻时,在原金属支架和支架堵塞后再次置入金属支架时,使用≥1根覆膜支架的累计通畅时间显著长于先后2次置入无覆膜金属支架者。     

生物降解消化道支架和金属消化道支架的应用价值

背景：消化道内镜下介入治疗是近20年发展起来的微创伤治疗新技术,已成为治疗消化道狭窄或梗阻的首选方法。 目的：总结分析生物降解消化道支架和金属消化道支架的应用价值。 方法：以“消化道、生物材料、金属支架、复合材料、复合支架”为中文关键词,采用计算机检索中国期刊全文数据库、PubMed数据库1993-01/2010-11相关文章。纳入生物消化道支架-金属消化道支架的应用等相关的文章,排除重复研究或Meta分析类文章。 结果与结论：共入选25篇文章进入结果分析。消化道狭窄采用内镜下高频电凝电切,微波、探条扩张等均有一定效果, 但有疗效短需反复治疗的缺点。金属内支架置入具有操作简便,创伤小,并发症少,且相对费用较低的优点。可降解支架可以解决良恶性狭窄的再通及瘘口的封堵等,在消化道疾病中的应用已经显示其有效的扩张性及临床安全性,但其材料的选择、支架的设计及降解时间的调节等都需要通过未来更多的临床应用来评估。     

脑血管置入材料的生物相容性及并发症

背景：虽然支架置入技术的发展为脑血管疾病提供了较为有效的治疗手段,但其安全性和有效性还有待进一步验证。 目的：阐述脑血管支架与宿主间的生物相容性,分析支架置入并发症的原因,并探讨管理方法。 方法：以 “脑血管病,支架,生物相容性,并发症”和“Cerebrovascular disease,stents,biocompatibility,complication” 为检索词,计算机检索中国期刊全文数据库、PubMed数据库(1993-01/2010-11) 与脑血管支架生物相容性、支架置入治疗并发症相关的文章,按纳入和排除标准对文献进行筛选,重点对18 篇文章进行分析讨论。 结果与结论：脑血管支架临床应用较多的是颅内支架,由于血管的管径限制支架的直径,不同病变对支架直径的要求不同。支架置入并发症主要有腹膜后血肿,颈动脉窦反应,高灌注综合征,脑血管痉挛和血栓形成。在各种脑血管支架中,金属支架生物相容性较差,聚合物支架、涂层支架和药物支架生物相容性均好于金属支架,能有效的预防支架置入后的再狭窄。治疗过程中进行充足的置入前准备,选择合适的支架类型,严格遵循适应证,支架置入中仔细观察病情变化,置入后良好的监测和管理可预防并发症的发生。     

金属胆道支架在恶性胆道梗阻治疗中的临床应用

目的：探讨金属胆道支架置人结合肿瘤区域化疗在恶性胆道梗阻治疗中的应用价值。方法：46例不能根治切除的恶性胆管梗阻患者中，42例行经皮肝穿刺胆道引流（PTCD）后支架置放术，另4例行经腹胆道支架置放术。支架置放术后，36例采用皮下埋置化疗泵化疗药物注射，8例采用分次动脉插管化疗药物灌注。结果：经PTCD成功后支架置人成功率95．2％，经腹支架置人成功率100％。结论：金属胆道支架置人成功率高，手术损伤，支架通畅率高，结合肿瘤区域化疗，可进一步提高疗效。     

颅内动脉狭窄支架置入与植入材料的生物相容性

背景：颅内动脉狭窄支架按照结构和材质可将血管内支架分为金属支架、聚合物支架、涂层支架等类型。那么哪一种支架更具临床应用价值呢？ 目的：对颅内动脉狭窄支架置入治疗的理论、应用、并发症及疗效进行评定,并分析植入材料的生物相容性。 方法：应用计算机应用计算机检索PubMed数据库及西文生物医学期刊文献数据库(EMCC)2000-01/2010-10 期间的相关文章,检索词为“Intracranial arterial stenosis,stent Implantation”,并限定文章语言种类为English。同时计算机检索中国期刊全文数据库(CNKI)等2000-01/2010-10期间的相关文章,检索词为“颅内动脉狭窄,支架置入”,并限定文章语言种类为中文。此外还手工查阅相关专著数部。纳入不同材料支架置入治疗颅内动脉狭窄的研究,包括基础研究、临床应用、并发症及材料的生物相容性评定。初检得到151篇文献,根据纳入标准选择33篇文章进行分析。 结果与结论：颅内动脉狭窄的支架置入治疗较单纯药物治疗有明显的优势。近年来,随着冠脉支架及Wingspan支架的运用,支架治疗颅内动脉狭窄已成为一种安全有效的方法。虽然支架置入治疗后会发生不同并发症如再狭窄、脑出血高灌注综合征、缺血性脑卒中等,但支架治疗颅内动脉狭窄在短期及中期有很好的疗效,同时远期疗效还有待进一步研究。提示,支架置入治疗颅内动脉狭窄是一种安全的方法,短、中期内有效,但远期疗效有待进一步研究。药物涂层支架和Wingspan 支架与人体的生物相容性并没有显著差异,尚待进一步论证。     

不同类型脑血管支架材料的特点及临床应用

背景：随着基础研究、临床应用,以及血管支架材料的不断发展,血管内支架置入治疗已被广泛应用于脑血管疾病治疗中。 目的：综述这几种支架材料的特点及临床应用情况。 方法：应用计算机检索CNKI数据库、万方数据库、PubMed数据库从建库到2014年3月的相关文献,中文检索关键词为“脑血管病,支架,生物相容性”,英文检索关键词为“cerebrovascular disease,stents,biocompatibility”。 结果与结论：按释放方式可将脑血管支架分为球囊扩张式支架与自膨式支架。最初应用的支架材料主要为裸金属材料,由记忆合金、医用不锈钢、钽、钴、镍钛合金等制成。由于金属支架置入后会释放金属离子,易致血栓形成,再狭窄率高,后来对其表面进行改性,出现了涂层支架与覆膜支架。支架置入治疗的围手术期并发症主要有过度灌注综合征、急性血栓形成、血管破裂和远端血管栓塞、血管痉挛和穿刺相关并发症,远期并发症主要是支架置入后再狭窄问题。相信随着科技的进步,支架材料和制作工艺的不断改进,血管支架置入治疗将更加安全有效。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

血管内支架材料特点与缺血性脑卒中的治疗效果

背景：新型血管内支架材料是目前脑血管疾病介入治疗的研究热点。 目的：分析血管内支架材料学特征及缺血性脑卒中治疗效果。 方法：第一作者于2012年12月应用计算机检索数据库的相关文章,中文检索词为“缺血性脑卒中;血管内支架;支架材料;介入治疗”,检索时间范围在2003至2012年,共检索到相关文献120篇,符合纳入标准并用于分析的文献24篇。 结果与结论：①金属裸支架在血液中长期存放有腐蚀、金属离子溶出和凝血性等现象,为解决金属材料存在的问题,可以通过金属支架表面改性来处理,提高金属材料的血液相溶性。②药物支架是将治疗药物涂于支架表面,使药物能够持续并高浓度的释放,防止支架置入后再狭窄。③覆膜血管内支架是在金属支架外表覆以可降解或不可降解的聚合物薄膜,抑制血管内皮增生,对血管平滑肌细胞具有良好的生物相容性,可以预防血管支架置入后再狭窄。血管内支架治疗可以降低缺血性脑卒中的风险,是一种安全有效的治疗手段,同时还可以改善缺血性脑病患者的认知功能障碍。基因及细胞种植支架材料在防治脑血管介入后再狭窄方面也具有一定优势,是血管内支架材料研究的新方向。     

国内外胰管支架材料发展状况及临床应用北大核心

背景:近年来,随着人们饮食习惯和生活习惯的改变,慢性胰腺炎发病率显著增高,内镜下胰管支架治疗慢性胰腺炎展现出良好的临床前景。目的:介绍各种支架材料的利弊,阐述国内外胰管支架材料发展状况及临床应用。方法:以"慢性胰腺炎,胰管支架"为中文检索词,以"chronic pancreatitis,pancreatic stent"为英文检索词,应用计算机在中国期刊全文数据库和Pub Med数据库检索2005年1月至2016年11月的相关文章,筛选出可用于体内外及临床研究的内镜下新型材料胰管支架。结果与结论:(1)内镜下胰管支架置入作为慢性胰腺炎的有效治疗手段之一,已成为国内外专家的共识,其中胰管支架材料的开发和应用显得尤为重要;(2)根据胰管支架材料的不同,可将胰管支架分为塑料支架、自膨胀金属支架、具有生物可降解性的支架;(3)塑料胰管支架与自膨胀金属胰管支架虽已广泛应用于临床,但其存在支架与胰管契合度欠佳、支架移位且需二次手术取出等问题;(4)生物可降解性的支架材料可在预期时间内于胰管中完全降解,避免了支架置入术后的诸多并发症。故具有生物可降解性的支架材料的开发及应用已成为国内外专家的研究热点。     

药物涂层支架在老年冠状动脉相关疾病治疗中的应用及评价

背景：药物涂层支架由于显著降低了冠脉内支架置入再狭窄的问题,使其应用范围不断扩大。 目的：从材料学及临床应用方面阐述如何提高老年心血管疾病中药物涂层支架的相容性。 方法：以 “药物涂成;心血管支架;生物相容性;老年;介入”为中文关键词;采用计算机检索1995-01/2010-10万方数据库及中国知网数据库相关文章。纳入与老年心血管疾病介入治疗中药物涂层的相关文章;排除重复研究或Meta分析类文章。以25篇文献为主重点分析了药物涂层支架在老年心血管疾病介入治疗中相容性。 结果与结论：老年冠状动脉粥样硬化性心脏病患者正日益增多,支架置入治疗疗效及应用价值在此领域已经得到循证医学的验证,但由于老年患者的年龄、身心状况等问题,以及长期置入支架后会导致血栓、动脉瘤、支架移位等并发症,所以老年患者置入支架的安全性及生物相容性有较高的要求。药物涂层支架的出现,将心血管介入治疗手段与局部缓释技术完美结合起来,大幅减低传统支架血管再狭窄概率,提高了置入后的生物相容性,为老年心血管疾病带来很好的治疗前景。     

脑血管支架种类及材料学特点与支架置入后的补体反应

目的:探讨脑血管支架材料学特点及补体反应与支架置入后并发症的关系。方法:以"脑血管支架,生物材料,生物相容性,再狭窄,补体反应"为中文检索词;以"rebrovascular disease,stent,therapy,complement"为英文检索词,采用计算机检索Pubmed数据库(http://www.ncbi.nlm.nih.gov/PubMed)及维普数据库(http://www.cqvip.com/)2000-01/2008-12有关脑血管支架材料学特点与支架置入后补体反应的文章;排除重复研究及Meta分析类文章。以24篇文献为主重点探讨了脑血管支架材料学特点及补体反应与支架置入后并发症的关系。结果:金属支架的生物相容性较差,聚合物支架、涂层支架和药物支架的生物相容性较好。脑血管支架作为治疗颅内外血管性疾病的一个重要手段,可降低颅内外动脉狭窄患者缺血性脑卒中的风险,但支架置入后的并发症如再狭窄等问题严重阻碍着该技术的进一步发展,免疫炎症反应在缺血性脑损伤机制中起着重要作用,生物材料对补体系统也有明显的影响。结论:选用合适的生物医用材料,脑血管支架置入治疗可明显降低脑血管病的死亡率。但要注意脑血管支架置入过程中以及置入后可能发生的并发症,给予积极的防治是非常重要的。研制新的生物医用材料,同时检测补体系统相关指标,将会提高脑血管支架置入治疗的成功率。     

Biliary stent replacement cytology

Using fluoroscopic guidance, polyethylene biliary stents are replaced endoscopically or percutaneously when bile duct stenosis recurs. To improve the sensitivity of conventional biliary cytology, we examined cells recovered from removed stents. Biliary stents removed endoscopically from each of 11 patients were rinsed with saline; next, the rinse was centrifuged and the sediment smeared and Papanicolaou stained. Three patients with choledocholithiasis had biliary stent replacement cytology (BSRC) to exclude a neoplastic etiology. Eight patients with clinicoradiologic evidence of hepatobiliary or pancreatic carcinoma had BSRCs performed for pathologic documentation of carcinoma. BSRC from six of eight patients with clinicoradiologically malignant biliary strictures contained malignant cells, predominantly in loose clusters, but also singly (sensitivity 75%, specificity 100%; positive predictive value 75%, negative predictive value 60%). Reparative epithelial atypia was also present in all cases. BSRC from two patients with clinicoradiological evidence of carcinoma of the biliary region and from three with choledocholithiasis contained only bile pigment, leukocytes, and benign epithelial cells. The sampling of cells which have accumulated on, or in biliary stents, improves the sensitivity of biliary cytology. This is most applicable when 1) a patient is inoperable, 2) tissue biopsy is neither feasible nor diagnostic, 3) prior brush, suction, percutaneous, or endoscopic needle aspiration cytology is inconclusive, and 4) permanent metal stent is needed. Diagn. Cytopathol. 61:233–237, 1997. © 1997 Wiley-Liss, Inc.     

Polymeric photosensitizer-embedded self-expanding metal stent for repeatable endoscopic photodynamic therapy of cholangiocarcinoma

Photodynamic therapy (PDT) is a new therapeutic approach for the palliative treatment of malignant bile duct obstruction. In this study, we designed photosensitizer-embedded self-expanding nonvascular metal stent (PDT-stent) which allows repeatable photodynamic treatment of cholangiocarcinoma without systemic injection of photosensitizer. Polymeric photosensitizer (pullulan acetate-conjugated pheophorbide A; PPA) was incorporated in self-expanding nonvascular metal stent. Residence of PPA in the stent was estimated in buffer solution and subcutaneous implantation on mouse. Photodynamic activity of PDT-stent was evaluated through laserexposure on stent-layered tumor cell lines, HCT-116 tumor-xenograft mouse models and endoscopic intervention of PDT-stent on bile duct of mini pigs. Photo-fluorescence imaging of the PDT-stent demonstrated homogeneous embedding of polymeric Pheo-A (PPA) on stent membrane. PDT-stent sustained its photodynamic activities at least for 2 month. And which implies repeatable endoscopic PDT is possible after stent emplacement. The PDT-stent after light exposure successfully generated cytotoxic singlet oxygen in the surrounding tissues, inducing apoptotic degradation of tumor cells and regression of xenograft tumors on mouse models. Endoscopic biliary in-stent photodynamic treatments on minipigs also suggested the potential efficacy of PDT-stent on cholangiocarcinoma. In vivo and in vitro studies revealed our PDT-stent, allows repeatable endoscopic biliary PDT, has the potential for the combination therapy (stent plus PDT) of cholangiocarcinoma.     

A Systematic Review and Meta-Analysis of Randomized Trials and Prospective Studies Comparing Covered and Bare Self-Expandable Metal Stents for the Treatment of Malignant Obstruction in the Digestive Tract

Background: Self-expandable metal stents (SEMS) are widely used for the palliative treatment of malignant gastrointestinal obstruction. Our aim was to evaluate the evidence comparing covered and bare SEMS in the digestive tract using meta-analytical techniques.Methods: A literature search was performed using PubMed, Cochrane Library, and Embase databases for comparative studies assessing the two types of stents. The primary outcomes of interest were stent patency and patient survival; second outcomes included technical success, clinical success, tumor ingrowth, tumor overgrowth, and stent migration. A random-effects model was conducted. Pooled analysis was done separately based on the different segments of the digestive tract.Results: Eleven studies (8 randomized controlled trials and 3 prospective cohort studies) including a total of 1376 patients were identified. Covered SEMS were equivalent to bare SEMS in terms of technical success, clinical success, stent patency (gastroduodenal obstruction: HR =0.87, 95% CI 0.53-1.42; colorectal obstruction: HR =0.89, 95% CI 0.18-4.45; biliary obstruction: HR =0.73, 95% CI 0.41-1.32) and survival rates (esophageal obstruction: HR =1.80, 95% CI 0.73-4.44; gastroduodenal obstruction: HR =0.83, 95% CI 0.55-1.26; biliary obstruction: HR =0.99, 95% CI 0.77-1.28), although bare stents were more prone to tumor ingrowth (esophageal obstruction: RR =0.10, 95% CI 0.01-0.77; gastroduodenal obstruction: RR =0.12, 95% CI 0.03-0.55; colorectal obstruction: RR =0.21, 95% CI 0.06-0.70; biliary obstruction: RR =0.21, 95% CI 0.06-0.69), whereas covered stents had the higher risk of stent migration (gastroduodenal obstruction: RR =5.01, 95% CI 1.53-16.43; colorectal obstruction: RR =11.70, 95% CI 2.84-48.27; biliary obstruction: RR =8.11, 95% CI 1.47-44.76) and tumor overgrowth (biliary obstruction: RR =2.03, 95% CI 1.08-3.78).Conclusion: Both covered and bare SEMS are comparable in efficacy for the palliative treatment of malignant obstruction in the digestive tract. Each type of the stents has its own merit and demerit relatively.     

In vivo and in situ evaluation of a wireless magnetoelastic sensor array for plastic biliary stent monitoring

This paper presents the in vivo and in situ evaluation of a system that wirelessly monitors the accumulation of biliary sludge in a plastic biliary stent. The sensing element, located within the stent, is a passive array of magnetoelastic resonators that is queried by a wireless electromagnetic signal. The in vivo and in situ testing uses commercially-available plastic biliary stents, each enhanced with an array of ribbon sensors (formed from Metglas? 2826 MB). The sensor array is approximately 70 mm long and contains individual resonators that are 1 mm in width and have lengths of 10 mm, 14 mm, and 20 mm. The array is anchored into the 2.8 mm inner-diameter stent using a thermal staking technique. For the in situ testing, an instrumented stent is placed in various locations within the abdominal cavity of a female domestic swine carcass to evaluate the wireless range of the system; these results show that a wireless signal can be obtained from a range of at least 7.5 cm from a sensor array covered in bile. The in vivo testing includes the endoscopic implantation of an instrumented stent into the bile duct of a swine. After implantation, the swine was housed for a period of 4 weeks, during which the animal showed no ill effects and followed the expected growth curve from 29 kg to 42 kg. At the conclusion of the in vivo test, the animal was euthanized, and the instrumented stent explanted and examined. The results presented in this paper indicate that the monitoring system does not adversely affect the health of the animal and can feasibly provide sufficient wireless range after implantation.