CorMatrix Cardiovascular, Inc, Roswell, Ga.
Saint Joseph's Translational Research Institute, Atlanta, Ga.
J Thorac Cardiovasc Surg. 2014 Jul;148(1):333-340.e1. doi: 10.1016/j.jtcvs.2013.10.048. Epub 2013 Dec 19.
A novel bioprosthetic tricuspid valve was constructed from an acellular extracellular matrix (ECM) bioscaffold. The valve's mechanical functionality and potential for histologic regeneration was evaluated in an ovine model.
The native tricuspid valves of 4 domestic sheep were excised and replaced with bioprosthetic valves constructed from the ECM bioscaffold material shaped into the form of a tube. In vivo function was assessed over time by transthoracic echocardiography. Animals were euthanized at 3, 5, 8, and 12 months after valve implantation, and explanted valves were examined for gross morphology and by qualitative histopathologic analysis.
All 4 sheep survived until the specified date. Forward flow by echocardiography was normal with trivial to mild regurgitation. Annular morphology and mobility of the leaflets appeared normal with excellent leaflet coaptation. Explanted valves were grossly normal at all time points and showed evidence of progressive tissue remodeling and integration at the host-tissue interface. Histopathologic analysis demonstrated massive host-cell infiltration, structural reorganization of the ECM bioscaffold, elastin generation at the annulus by 3 months, and increased collagen organization and glycosaminoglycan presence in the leaflets by 5 months, with no evidence of foreign body response.
When implanted in the form of a tubular valve, the acellular ECM bioscaffold demonstrates feasibility as a biomechanically sound bioprosthetic tricuspid valve replacement with evidence of progressive endothelialization and constructive tissue remodeling.
我们构建了一种新型的无细胞细胞外基质（ECM）生物支架瓣叶，用于构建生物假体三尖瓣。我们评估了该瓣膜在绵羊模型中的机械功能和组织再生潜力。
我们从 4 只绵羊的原生三尖瓣中取出瓣膜，并将其替换为 ECM 生物支架材料制成的管状生物假体瓣膜。通过经胸超声心动图评估体内功能随时间的变化。在瓣膜植入后 3、5、8 和 12 个月，对动物进行安乐死，并对植入的瓣膜进行大体形态和定性组织病理学分析。
所有 4 只绵羊均存活至指定日期。超声心动图显示前向血流正常，仅有轻微至轻度反流。瓣环形态和瓣叶活动度正常，瓣叶对合良好。在所有时间点，植入的瓣膜大体上均正常，在宿主组织界面处显示出进行性组织重塑和整合的迹象。组织病理学分析显示大量宿主细胞浸润，ECM 生物支架的结构重排，3 个月时在瓣环处生成弹性蛋白，5 个月时瓣叶中胶原蛋白组织增加和糖胺聚糖存在，无异物反应证据。
以管状瓣膜的形式植入时，无细胞 ECM 生物支架具有作为机械性能良好的生物假体三尖瓣置换物的可行性，具有进行性内皮化和建设性组织重塑的证据。
