Carpentier A
Département de Chirurgie Cardio-Vasculaire et de Transplantation d'Organes, Hôpital Broussais, Paris.
Bull Acad Natl Med. 1996 Feb;180(2):363-78; discussion 378-80.
This article reports the research which led to the use of animal connective tissues in the construction of valvular prostheses and those which led to the use of electrically stimulated skeletal muscle for cardiac assistance. Although, very different at first glance these research have in common the transformation of biological tissues by physical or chemical means to adapt them to a new function. 1) Once implanted in a different species, animal connective tissues are destroyed by immunological reactions and collagen degeneration. These lesions can be prevented by both maskage of the antigenic groups and intermolecular crosslinking using Glutaraldehyde. The durability of such chemically treated tissues is based upon the stability of the biological material (concept of bioprosthesis) and not upon cell survival or tissue regeneration by host cell ingrowth (concept of graft). The valvular bioprostheses made from Glutaraldehyde treated pericardial tissue, keep after this treatment their advantage of biological tissues: they are not thrombogenic and do not require anticoagulation contrary to mechanical valves. Although they have a limited durability up to 10 to 15 years due to tissue calcification, they represent 40% of the valvular prostheses used in clinical practice today. 2) The clinical use of electrostimulated skeletal muscle has been delayed for a long time because of fatigue lesions. An original protocol of progressive sequential stimulation prior to the use of muscle prevents fatigue by the transformation of type I fatigable myosin into type II non fatigable myosin. The conditionned muscle i.e.: the latissimus dorsi, is then wrapped around the ventricles to either reinforce cardiac contraction or to replace a portion of the heart. In the past 10 years, this new operation of "dynamic cardiomyoplasty", has been performed in 84 patients suffering from the end stage heart failure in our institution and in over 500 patients throughout the world with significant functional improvement.
本文报道了两项研究，一项是关于在心脏瓣膜假体构建中使用动物结缔组织，另一项是关于使用电刺激骨骼肌来辅助心脏功能。尽管乍一看这两项研究差异很大，但它们的共同之处在于通过物理或化学手段对生物组织进行改造，使其适应新的功能。1）一旦植入不同物种，动物结缔组织会因免疫反应和胶原变性而遭到破坏。通过对抗抗原基团以及使用戊二醛进行分子间交联，可预防这些损伤。这种经化学处理的组织的耐久性基于生物材料的稳定性（生物假体概念），而非宿主细胞向内生长实现的细胞存活或组织再生（移植概念）。由戊二醛处理过的心包组织制成的心脏瓣膜生物假体，在这种处理后仍保留生物组织的优势：它们不会引发血栓形成，与机械瓣膜不同，不需要进行抗凝。尽管由于组织钙化，它们的耐久性有限，最多可达10至15年，但它们占当今临床实践中使用的心脏瓣膜假体的40%。2）由于疲劳损伤，电刺激骨骼肌的临床应用长期被推迟。在使用肌肉之前采用渐进式顺序刺激的原始方案，通过将I型易疲劳肌球蛋白转化为II型不易疲劳肌球蛋白来预防疲劳。经过预处理的肌肉，即背阔肌，然后包裹在心室周围，以增强心脏收缩或替代部分心脏功能。在过去10年里，我们机构对84例终末期心力衰竭患者以及全球500多例患者实施了这种新的“动力性心肌成形术”手术，患者功能得到显著改善。
