小口径人工血管血液相容性

学术背景：大口径人造血管的研究已取得突破性进展，在临床上得到广泛应用。而在小口径人造血管（直径小于6mm）研究方面，由于存在血管栓塞以及生物相容性等方面的核心问题没有得到有效解决，离实际应用还有很大的距离。目的：简单介绍人造血管的研究现状，分析小口径人造血管研制中存在的问题，阐述如何提高血液相容性方法。检索策略：应用计算机检索中国知网（www．cnki.net）及Medline（www.pubmed.com）1975-01／2007-08有关小口径人造血管血液相容性方面的文献，中文检索词“人造血管，聚氨酯，血液相容性”：英文检索词“Vascular grafts，Polyurethane，Blood Compatibillty”。初检得到143篇文献，包括中文28篇，英文115篇。文献评价：阅读标题和摘要进行初筛，排除因研究目的与本研究无关者54篇，内容重复性的研究64篇，保留25篇中英文文献进一步分析。其中动物实验和在体、离体、细胞学实验13篇，综述、述评、讲座类文献12篇。资料综合：①以往用于人造血管制造的主要材料有涤纶、聚四氟乙烯、真丝等，而具备良好的顺应性、耐磨性、弹性、生物相容性及一定的抗凝血性的聚氨酯则是目前被研究最多的人造血管制造材料。②小口径人造血管存在的主要问题是人造血管完全没有抗血栓性，血液流经内腔时，由于血流量小，流速慢，在人造血管腔面易形成附壁血栓，随之血凝亢进，血流更缓慢，血栓层增厚，最终导致人造血管闭塞。③在解决材料的血液相容性问题上，人们对材料表面的修饰研究得较多，然而，处于生物系统中的材料由于接触到体液、有机大分子、酶、自由基、细胞等多种因素，其生物学环境极为复杂，表面修饰的方法对血液相容性的改善有限。因此，应用组织工程的方法在材料表面原位培养人体内皮细胞使材

Blood compatibility of small-caliber vascular grafts

BACKGROUND： At present, a breakthrough study has been achieved for the big-caliber vascular grafts, which have been widely applied in the clinical practice. While there are still some unsolved key problems in field of the small-caliber （less than 6 mm diameter） vascular grafts, such as vascular embolism and histocompatibility, which obstructs the practical use of small-caliber vascular grafts. OBJECTIVE： To introduce the current study of vascular grafts, analyze the problems of designing small-caliber vascular grafts, and explain the method of enhancing blood compatibility. RETRIEVAL STRATEGY： A computer-based search was undertaken in www.cnki.net and Medline （www.pubmed.com） to identify the articles about the blood compatibility of small-caliber vascular graft between January 1975 and August 2007, with the key words of ＂Vascular grafts, Polyurethane, Blood compatibility＂ in Chinese and English. After the primary check, a total of 143 articles were collected, including 28 Chinese ones and 115 English ones. LITERATURE EVALUATION： The titles and abstracts were screened preliminarily, then there were 54 articles excluded due to unrelated objectives and 64 articles deleted due to repeated contents, finally 25 literatures were involved in the analysis, including 13 ones regarding animal experiments, and in vivo, ex vivo, cytological trials, 12 ones regarding reviews, commentaries and lectures. DATA SYNTHESIS： 1.The materials for blood vessel prosthesis are mainly dacron, polytef, natural silk and so on, while polyurethane with good compliance, abradability, elasticity, biocompatibility and anticoagulant property, has gained much attraction.2.Small-caliber vascular grafts are absents in the antithrombotic effect, and may result in vascular occlusion of grafts through mural thrombosis occurred in lumen of blood vessel, which induces the blood coagulation hyperfunction, slows the blood flow, and thickens thrombus layer.3.As for the blood compatibility, there are many studies about the surface modifi