Barnhart G R, Jones M, Ishihara T, Chavez A M, Rose D M, Ferrans V J
J Thorac Cardiovasc Surg. 1982 Apr;83(4):618-31.
We compared the clinical, hemodynamic, and morphological findings in 18 young sheep in which porcine valvular bioprosthesis (eight animals) and bovine pericardial bioprostheses (10 animals) were implanted in the tricuspid position. At the time of terminal elective studies (mean of 5.2 +/- 0.2 months after implantation), six animals had ascites, 16 had hepatic congestion, and four had bioprosthetic valvular infection. Hemodynamic studies (n = 10) showed that the tricuspid transvalvular mean diastolic gradients were not different at implantation and at termination of the study (4.7 +/- 0.8 versus 4.9 +/- 0.9 mm Hg); however, tricuspid valve end-diastolic gradients increased from 1.2 +/- 0.6 to 3.9 +/- 0.5 mm Hg (p less than 0.01). Each of the 18 valves had calcific deposits. Quantitative studies revealed that implanted porcine valvular bioprosthesis (n = 7) contained a mean of 323 +/- 165 mg of calcium/gm of dry weight of cuspal tissue, in contrast to 0.2 mg/gm in unimplanted porcine valvular prostheses. Similarly, implanted bovine pericardial bioprostheses (n = 6) contained a mean of 421 +/- 115 mg of calcium/gm of dry weight of cuspal tissue, in contrast to 0.3 mg/gm im unimplanted bovine pericardial bioprostheses. Morphological findings in both types of bioprostheses included calcific deposits, collagen degeneration, leaflet immobilization and retraction, and fibrous sheaths. The latter were more extensive in bovine pericardial bioprostheses than in porcine valvular bioprostheses. We conclude: (1) that the pathological alterations which develop in bovine pericardial bioprostheses are generally similar to those in porcine valvular bioprostheses, but may be more severe; (2) that these alterations lead to physiological and clinical sequelae similar to those of bioprosthetic valvular failure in human subjects; and (3) that young sheep constitute an excellent experimental model for in vivo testing of bioprosthetic cardiac valves.
我们比较了18只幼羊的临床、血流动力学和形态学结果，这些幼羊的三尖瓣位置分别植入了猪瓣膜生物假体（8只动物）和牛心包生物假体（10只动物）。在终末期选择性研究时（植入后平均5.2±0.2个月），6只动物出现腹水，16只出现肝充血，4只发生生物假体瓣膜感染。血流动力学研究（n = 10）显示，三尖瓣跨瓣平均舒张期梯度在植入时和研究结束时无差异（4.7±0.8与4.9±0.9 mmHg）；然而，三尖瓣舒张末期梯度从1.2±0.6增加到3.9±0.5 mmHg（p＜0.01）。18个瓣膜均有钙化沉积。定量研究表明，植入的猪瓣膜生物假体（n = 7）每克瓣叶组织干重平均含323±165毫克钙，而未植入的猪瓣膜假体为0.2毫克/克。同样，植入的牛心包生物假体（n = 6）每克瓣叶组织干重平均含421±115毫克钙，而未植入的牛心包生物假体为0.3毫克/克。两种生物假体的形态学结果包括钙化沉积、胶原退变、瓣叶固定和回缩以及纤维鞘。后者在牛心包生物假体中比在猪瓣膜生物假体中更广泛。我们得出结论：（1）牛心包生物假体发生的病理改变通常与猪瓣膜生物假体相似，但可能更严重；（2）这些改变导致的生理和临床后果与人体生物假体瓣膜功能衰竭相似；（3）幼羊是生物假体心脏瓣膜体内测试的优秀实验模型。
