Janson Jacques T, Coetzee Andre, Rossouw Gawie, Loftus Izak, Murray Adriaan, Rossouw Pieter, Herbst Philip
Division of Cardiothoracic Surgery, Stellenbosch University, Tygerberg, South Africa.
Division of Anesthesiology and Critical Care, Stellenbosch University, Tygerberg, South Africa.
Ann Thorac Surg. 2017 Aug;104(2):584-592. doi: 10.1016/j.athoracsur.2016.11.060. Epub 2017 Mar 6.
This study evaluated the use of an autologous vein graft, supported by expanded polytetrafluoroethylene (ePTFE) chordae tendineae, to replace an anterior mitral valve leaflet.
A double-layered autologous jugular vein graft, supported by ePTFE chords, was used to create an anterior mitral valve leaflet in 21 sheep. Mitral valve function was monitored with echocardiography for up to 10 months. Surviving sheep were euthanized between 6 and 10 months later, and vein implants were examined histologically.
One sheep died intraoperatively. Fourteen sheep had trace to mild mitral regurgitation (MR), 5 had mild to moderate MR, and 1 had moderate to severe MR. Ten sheep died between 2 days and 6.2 months. Echocardiography at 6 months showed MR progression in 8 of 11 sheep. The vein leaflet developed intimal fibroplasia and fibrous proliferation in response to the increased stress on the tissue, but the vein remained flexible without shortening or contracture. The 6- to 10-month vein implants showed viability with intact endothelium, myofibroblasts, collagen, and elastin. A normal healing pattern was seen at the suture lines, and no calcification was observed in the vein leaflet apart from the ePTFE sutures.
Autologous vein has the potential to function as a mitral valve leaflet substitute because it adapted morphologically and remained viable in the intracardiac position. Technical refinement in creating and implanting the leaflet is needed to improve the progression of MR.
本研究评估了使用由膨体聚四氟乙烯（ePTFE）腱索支撑的自体静脉移植物来替代二尖瓣前叶。
使用由ePTFE腱索支撑的双层自体颈静脉移植物在21只绵羊中构建二尖瓣前叶。用超声心动图监测二尖瓣功能长达10个月。存活的绵羊在6至10个月后实施安乐死，并对静脉植入物进行组织学检查。
1只绵羊在术中死亡。14只绵羊有微量至轻度二尖瓣反流（MR），5只绵羊有轻度至中度MR，1只绵羊有中度至重度MR。10只绵羊在2天至6.2个月之间死亡。6个月时的超声心动图显示11只绵羊中有8只的MR病情进展。静脉瓣叶因组织上增加的应力而出现内膜纤维增生和纤维增殖，但静脉仍保持柔韧，无缩短或挛缩。6至10个月的静脉植入物显示有活力，内皮、肌成纤维细胞、胶原蛋白和弹性蛋白完整。在缝线处可见正常的愈合模式，除了ePTFE缝线外，静脉瓣叶未观察到钙化。
自体静脉有潜力作为二尖瓣叶替代物发挥功能，因为它在形态上适应且在心脏内位置保持存活。需要在构建和植入瓣叶方面进行技术改进以改善MR的病情进展。
