Lalezari Shirin, Hazekamp Mark G, Bartelings Margot M, Schoof Paul H, Gittenberger-De Groot Adriana C
Department of Anatomy and Embryology, Leiden University Medical Center,, Leiden, The Netherlands.
J Thorac Cardiovasc Surg. 2003 Oct;126(4):1053-60. doi: 10.1016/s0022-5223(03)00971-1.
Transposition of the great arteries is currently treated by performing the arterial switch operation. Dilatation of the neoaortic root is a late complication with unknown cause. Samples of patients with untreated transposition of the great arteries and patients with normally related great arteries were compared to investigate a possible role for vascular remodeling in the dilatation process.
Aortic and pulmonary artery vessel wall and sinus samples were taken from 20 untreated human heart specimens with transposition of the great arteries and 9 age-matched, normal, postmortem human heart specimens, divided into 2 groups according to age. Routine histology and immunohistochemical staining for smooth muscle cell differentiation markers alpha-smooth muscle actin, SM22, and calponin were performed.
This study revealed structural differences between the normal aorta and pulmonary artery in the early group, which became more pronounced in the late group. In the early stage in transposition of the great arteries, no marked differences were seen between the aorta and pulmonary artery. With increasing age, however, there was a pronounced down-regulation of all smooth muscle cell markers in the pulmonary artery.
There is a structural difference between the normal neonatal aorta and pulmonary artery. The great arteries in transposition of the great arteries differ from each other and from normal vessels, indicating a structural vascular difference in transposition of the great arteries. In the pulmonary artery and sinus of untreated transposition of the great arteries, there is a dedifferentiation of smooth muscle cells with increasing age that we could not correlate to altered flow. This structural abnormality might provide an explanation for the neoaortic root dilatation that has been reported as a late complication of the arterial switch operation.
目前大动脉转位通过动脉调转手术进行治疗。新主动脉根部扩张是一种病因不明的晚期并发症。对未经治疗的大动脉转位患者和大动脉关系正常患者的样本进行比较，以研究血管重塑在扩张过程中可能发挥的作用。
从20例未经治疗的大动脉转位人类心脏标本以及9例年龄匹配的正常尸检人类心脏标本中获取主动脉和肺动脉血管壁及窦样本，根据年龄分为2组。进行常规组织学检查以及针对平滑肌细胞分化标志物α-平滑肌肌动蛋白、SM22和钙调蛋白的免疫组织化学染色。
本研究揭示了早期组正常主动脉和肺动脉之间的结构差异，在晚期组中这种差异更加明显。在大动脉转位的早期阶段，主动脉和肺动脉之间未见明显差异。然而，随着年龄增长，肺动脉中所有平滑肌细胞标志物均出现明显下调。
正常新生儿主动脉和肺动脉之间存在结构差异。大动脉转位中的大动脉彼此之间以及与正常血管不同，表明大动脉转位存在结构性血管差异。在未经治疗的大动脉转位的肺动脉和窦中，随着年龄增长平滑肌细胞出现去分化，而我们无法将其与血流改变联系起来。这种结构异常可能为作为动脉调转手术晚期并发症报道的新主动脉根部扩张提供一种解释。
