Collagen fiber disruption occurs independent of calcification in clinically explanted bioprosthetic heart valves
Collagen fiber disruption occurs independent of calcification in clinically explanted bioprosthetic heart valves
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DOI：
10.1002/jbm.10293
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发表时间：
2002-12-05
期刊：
影响因子：
--
通讯作者：
Schoen, FJ
中科院分区：
文献类型：
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作者：
Sacks, MS;Schoen, FJ
生物瓣膜(BHV)的耐久性受到组织退化的严重限制，表现为钙化和细胞外基质的机械损伤。对矿化机制的广泛研究已经导致了预防策略的提出，但对于理解非钙化基质损伤的机制的工作很少。本研究验证了一种假说，即机械因素对瓣膜结构基质的钙化非依赖性损伤发生在临床植入物中，并可能导致猪主动脉BHV结构失效。我们用小角光散射法(SALS)定量评估了14个猪主动脉瓣膜生物瓣膜的胶原纤维取向和结构完整性，并与形态分析进行了比较。根据放射学评估，外植体的钙化程度从0(无)到1+(微小)到4+(广泛)不等。使用0.254 mm的网格对整个切除的牙尖进行SALS测试，所产生的结构信息用于生成局部胶原纤维损伤的地图，并与钙化沉积的位置进行比较。所有42个牙尖都有明显的非钙化性结构损伤。在29个钙化的牙尖中，结构损伤与钙化沉积在空间上始终是不同的，其分布通常与体外耐久性试验中发现的猪BHV相似。我们的结果表明，非钙化降解机制依赖于尖端机械，这可能是导致猪主动脉BHV失败的原因之一。(C)2002年威利期刊公司。
The durability of bioprosthetic heart valves (BHV) is severely limited by tissue deterioration, manifested as calcification and mechanical damage to the extracellular matrix. Extensive research on mineralization mechanisms has led to prevention strategies, but little work has been done on understanding the mechanisms of noncalcific matrix damage. The present study tested the hypothesis that calcification-independent damage to the valvular structural matrix mediated by mechanical factors occurs in clinical implants and could contribute to porcine aortic BHV structural failure. We correlated quantitative assessment of collagen fiber orientation and structural integrity by small angle light scattering (SALS) with morphologic analysis in 14 porcine aortic valve bioprostheses removed from patients for structural deterioration following 5-20 years of function. Calcification of the explants varied from 0 (none) to 1 + (minimal) to 4 + (extensive), as assessed radiographically. SALS tests were performed over entire excised cusps using a 0.254-mm spaced grid, and the resultant structural information used to generate maps of the local collagen fiber damage that were compared with sites of calcific deposits. All 42 cusps showed clear evidence of substantial noncalcific structural damage. In 29 cusps that were calcified, structural damage was consistently spatially distinct from the calcification deposits, generally in a distribution similar to that noted in porcine BHV subjected to in vitro durability testing. Our results suggest a mechanism of noncalcific degradation dependent on cuspal mechanics that could contribute to porcine aortic BHV failure. (C) 2002 Wiley Periodicals, Inc.