Schoen F J, Mitchell R N, Jonas R A
Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.
J Heart Valve Dis. 1995 Jul;4 Suppl 1:S72-5; discussion S75-6.
Since structure-function correlations have not been determined for cryopreserved allograft heart valves, we studied 20 explanted valves in place several hours to nine years, as either orthotopic aortic valves/root replacements or right ventricle to pulmonary artery conduits. They were explanted primarily due to growth-related conduit or valve stenosis, valve regurgitation, or infection. Controls included seven unused cryopreserved allograft valves and 16 aortic valves removed from transplanted allograft hearts obtained at either autopsy (n = 15) or retransplantation (n = 1), two days to four years postoperatively, following myocardial rejection (n = 4), graft coronary arteriosclerosis (n = 4), and other (n = 8). Analysis included gross inspection, radiography, light microscopy, electron microscopy, and immunohistochemical studies (to allow identification/localization of endothelial cells, mononuclear inflammatory cells, and T and B lymphocyte subsets). Cryopreserved allograft valves implanted more than one day had progressively severe loss of normal structure and were devoid of surface endothelium and stainable deep connective tissue cells. Inflammatory cellularity varied from none (most valves) to prominent (primarily T lymphocytes in one valve). Transmission electron microscopy of three long term valvular allografts revealed no viable cells, remarkable preservation of the collagenous valve matrix and focal cell-oriented calcification. In contrast, aortic valves from transplanted hearts showed remarkable structural preservation, including layered architecture, endothelium and deep connective tissue cells; inflammatory infiltrates were generally sparse, even in cases with fatal myocardial rejection. We conclude that cryopreserved allograft valves are morphologically non-viable valves, whose structural basis for function seems primarily related to the largely preserved collagen.(ABSTRACT TRUNCATED AT 250 WORDS)
由于尚未确定冷冻保存的同种异体心脏瓣膜的结构-功能相关性，我们研究了20个已植入原位数小时至九年的瓣膜，这些瓣膜作为原位主动脉瓣膜/根部置换物或右心室至肺动脉管道。它们被取出主要是由于与生长相关的管道或瓣膜狭窄、瓣膜反流或感染。对照组包括7个未使用的冷冻保存同种异体瓣膜和16个从尸检（n = 15）或再次移植（n = 1）获得的移植同种异体心脏中取出的主动脉瓣膜，术后两天至四年，分别因心肌排斥反应（n = 4）、移植冠状动脉硬化（n = 4）和其他原因（n = 8）。分析包括大体检查、放射学检查、光镜检查、电镜检查和免疫组化研究（以识别/定位内皮细胞、单核炎性细胞以及T和B淋巴细胞亚群）。植入超过一天的冷冻保存同种异体瓣膜正常结构逐渐严重丧失，表面无内皮细胞且深部结缔组织细胞不可染色。炎症细胞数量从无（大多数瓣膜）到显著（一个瓣膜中主要为T淋巴细胞）不等。对三个长期瓣膜同种异体移植的透射电镜检查显示无活细胞，胶原瓣膜基质保存良好且有局灶性细胞性钙化。相比之下，移植心脏的主动脉瓣膜结构保存良好，包括分层结构、内皮细胞和深部结缔组织细胞；即使在致命性心肌排斥反应的病例中，炎症浸润通常也很稀疏。我们得出结论，冷冻保存的同种异体瓣膜是形态上无活力的瓣膜，其功能的结构基础似乎主要与大量保存的胶原蛋白有关。（摘要截断于250字）
