Mekontso-Dessap Armand, Kirsch Matthias, Guignambert Christophe, Zadigue Patricia, Adnot Serge, Loisance Daniel, Eddahibi Saadia
Institut National de la Santé et de la Recherche Médicale, Faculté de Médecine de Créteil, Créteil, France.
J Thorac Cardiovasc Surg. 2006 Mar;131(3):651-8. doi: 10.1016/j.jtcvs.2005.08.048.
Late graft occlusions after coronary artery bypass grafting have been ascribed to neointimal hyperplasia. Given the pivotal role of smooth muscle cells in the pathogenesis of neointimal hyperplasia and the phenotypic heterogeneity of smooth muscle cells across vessels, we hypothesized that differences in long-term graft patency are at least partly related to differences in smooth muscle cell properties. The aim of the present study was to compare the vascular-wall remodeling of human internal thoracic artery, radial artery, and saphenous vein bypass conduits.
We evaluated the intimal thickening of the human graft segments in organ cultures (histopathology, morphometric, and immunofluorescence analyses) and assessed the properties of cultured smooth muscle cells isolated from these vessels in terms of cell proliferation (tritiated thymidine incorporation), migration (modified Boyden chamber), and collagen synthesis (tritiated proline incorporation).
The total vessel-wall growth index and the intimal growth index were significantly higher for saphenous vein rings than for radial artery and internal thoracic artery rings. Immunofluorescence analyses showed predominant involvement of smooth muscle cells in neointimal growth induced by organ culture of saphenous vein rings. Cell proliferation was significantly higher in saphenous vein smooth muscle cells than in radial artery smooth muscle cells and significantly higher in radial artery smooth muscle cells than in internal thoracic artery smooth muscle cells. Migration of smooth muscle cells from saphenous vein grafts was significantly greater than from internal thoracic artery or radial artery grafts. Collagen synthesis was similar in smooth muscle cells from internal thoracic artery, radial artery, and saphenous vein grafts.
Ex vivo vascular-wall remodeling and smooth muscle cell intrinsic growth and migratory properties are dissimilar between arterial and venous grafts and might shed light on reported angiographic patency rates of these grafts.
冠状动脉旁路移植术后晚期移植物闭塞被认为与新生内膜增生有关。鉴于平滑肌细胞在新生内膜增生发病机制中的关键作用以及不同血管中平滑肌细胞的表型异质性，我们推测长期移植物通畅性的差异至少部分与平滑肌细胞特性的差异有关。本研究的目的是比较人胸廓内动脉、桡动脉和大隐静脉旁路移植管道的血管壁重塑情况。
我们在器官培养中评估了人移植物节段的内膜增厚情况（组织病理学、形态计量学和免疫荧光分析），并从细胞增殖（氚标记胸腺嘧啶核苷掺入法）、迁移（改良博伊登小室法）和胶原合成（氚标记脯氨酸掺入法）方面评估了从这些血管中分离出的培养平滑肌细胞的特性。
大隐静脉环的总血管壁生长指数和内膜生长指数显著高于桡动脉环和胸廓内动脉环。免疫荧光分析显示，平滑肌细胞在大隐静脉环器官培养诱导的新生内膜生长中起主要作用。大隐静脉平滑肌细胞的增殖显著高于桡动脉平滑肌细胞，桡动脉平滑肌细胞的增殖显著高于胸廓内动脉平滑肌细胞。大隐静脉移植物中平滑肌细胞的迁移显著大于胸廓内动脉或桡动脉移植物。胸廓内动脉、桡动脉和大隐静脉移植物的平滑肌细胞中的胶原合成相似。
动脉和静脉移植物的体外血管壁重塑以及平滑肌细胞的内在生长和迁移特性不同，这可能有助于解释这些移植物报告的血管造影通畅率。
