Pathology of Substitute Heart Valves: New Concepts and Developments
Pathology of Substitute Heart Valves: New Concepts and Developments
复制标题
替代心脏瓣膜的病理学：新概念和发展
作者：
F. Schoen;R. Levy
所有类型的当代心脏瓣膜替代物都存在限制其成功的缺陷和并发症。机械瓣膜和生物瓣膜具有固有的阻塞性，尤其是小尺寸瓣膜。机械瓣膜与血栓栓塞问题有关;几乎所有机械瓣膜接受者使用的长期抗凝治疗都会导致一些人出血。钙化限制了猪和心包生物瓣膜、同种异体移植瓣膜和尚处于实验阶段的三叶聚合物瓣膜的成功。猪、心包和同种异体瓣膜中钙化的主要机制是细胞介导的，在移植细胞的膜和细胞器中成核。在聚合物瓣叶瓣膜中，钙化是外在的（粘附血栓中）和内在的（固体弹性体中的表面下和非细胞）。尽管如此，除了少数值得注意的例外，当代机械瓣膜是耐用的。人工瓣膜和生物瓣膜的其他重要潜在并发症包括瓣周漏、心内膜炎或外源性功能干扰。此外，主动脉瓣同种异体移植物经历进行性非钙化变性、撕裂、下垂和/或回缩。对取出的长期冷冻保存的同种异体移植物外植体的研究显示出严重退化，正常结构细节变形，内皮和深层结缔组织细胞丢失，以及可变的炎性细胞结构。因此，它们是形态学上不可存活的瓣膜，其功能的结构基础似乎主要与大量保存的胶原蛋白有关，并且它们不太可能具有生长、重塑或表现出活性代谢功能的能力。由于瓣尖固有钙化是导致人工生物瓣膜再次手术的主要病理过程，因此应积极防止矿物质沉积物形成。最有前景的抗钙化技术是使用清洁剂（如十二烷基硫酸钠、2-氨基油酸、阳离子（如Fe 3+或Al 3+））或二膦酸盐药物（如乙烷羟基二膦酸盐）或醛的组织保存替代品（如聚环氧化物化合物或染料介导的光氧化处理）对戊二醛固定的组织进行植入前处理。正在研究的有前景的创新概念包括生物瓣膜支架设计和组织安装技术的改良，以减少瓣尖应力，组织治疗以增强内皮化，无支架猪瓣膜和最低交联自体心包瓣膜。（J Card Surg 1994; 9[Suppl]：222-227）
All types of contemporary cardiac valve substitutes suffer deficiencies and complications that limit their success. Mechanical and bioprosthetic valves are intrinsically obstructive, especially in small sizes. Mechanical valves are associated with thromboembollc problems; the chronic anticoagulation used in virtually all mechanlcal valve recipients causes hemorrhage in some. Calcification limits the success of porcine and pericardial bio‐prostheses, allograft valves, and the yet experimental trileaflet polymeric prostheses. The predominant mechanism of calcification in porcine, pericardial, and allogratt valves is cell mediated, being nucleated at the membranes and in organelles of the transplanted cells. In polymeric leaflet valves, calcification is both extrinsic (in adherent thrombus) and Intrinsic (subsurface and acellular in the solid elastomer). Nevertheless, except for a few notable exceptions, contemporary mechanical valves are durable. Other Important potential complications of prosthetic and bioprosthetic valves include paravalvular leak, endocarditis, or extrinsic interference with function. Moreover, aortic valvular allografts undergo progresshe noncalclfic degeneration, tearing, sagging, and/or retraction. Studies of retrieved long‐term cryopreserved allograft explants demonstrate severe degeneration, with distortion of normal architectural detail, loss of endothelial and deep connective tissue cells, and variable inflammatory cellularity. Thus, they are morphologically nonviable valves, whose structural basis for function seems primarily related to the largely preserved collagen, and they are unlikely to have the capacity to grow, remodel, or exhibit active metabolic functions. Since calcification intrinsic to the cusps is the major pathologic process necessitating bioprosthetic valve reoperations, efforts to prevent formation of mineral deposits are active. The most promising anticalcification techniques are preimplantation treatments of glutaraldehyde fixed tissue with either detergents such as sodium dodecyl sulfate, 2‐amino oleic acid, cations such as Fe3+ or Al3+, or dlphosphonate drugs such as ethane hydroxydiphosphonate, or tissue preservation alternatives to aldehydes, such as polyepoxide compounds or dye mediated photooxidation treatment. Promising innovative concepts also under Investigation include modifications of bioprosthetic valve stent design and tissue mounting techniques to reduce cuspal stresses, tissue treatments to enhance endothelialization, nonstented porclne valves, and minimally cross‐linked autologous pericardial valves. (J Card Surg 1994; 9[Suppl]:222–227)
DOI：
10.1002/jbm.820271203
发表时间：
1993-12-01
期刊：
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH
影响因子：
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作者：
HIRSCH, D;DRADER, J;LEVY, RJ
通讯作者：
LEVY, RJ