Grewal Nimrat, Gittenberger-de Groot Adriana C, Lindeman Jan H, Klautz Arthur, Driessen Antoine, Klautz Robert J M, Poelmann Robert E
Department of Cardiothoracic Surgery, Leiden University Medical Center, Leiden, The Netherlands.
Department of Cardiothoracic Surgery, Amsterdam University Medical Center, Amsterdam, The Netherlands.
Ann Cardiothorac Surg. 2022 Jul;11(4):380-388. doi: 10.21037/acs-2021-bav-14.
A bicuspid aortic valve (BAV) is the most prevalent congenital cardiac anomaly, in which the valve has only two leaflets, instead of the normal three. Patients with a BAV have an increased risk of aneurysm formation and the development of an aortic dissection. Vascular smooth muscle cells in both the non- and dilated aortic wall are characterized by a maturation defect in all BAV patients, as compared to patients with a tricuspid aortic valve, which can contribute to inherent developmental susceptibility. Besides structural abnormalities of the vascular wall, a turbulent blood flow, caused by bicuspid valve geometry, could expedite the pathological process in the aortic wall, leading to aortopathy. Although the risk for aortopathy is significant, not all BAV patients experience (acute) aortic complications in their lifespan, highlighting the complexity of the pathogenetic process. Recent studies have focused on the embryonic development of semilunar valves and the ascending aortic wall. Their findings highlight that a defect in the embryogenesis could not only explain the development of a malformed aortic valve but also the increased risk for ascending aorta and arch pathology. This review presents an overview of the normal and abnormal development of the aortic valve and the aortic wall: a common defect in early embryogenesis causes the development of a BAV and associated aortopathy.
二叶式主动脉瓣（BAV）是最常见的先天性心脏异常，即该瓣膜只有两个瓣叶，而非正常的三个瓣叶。患有BAV的患者发生动脉瘤形成和主动脉夹层的风险增加。与三尖瓣主动脉瓣患者相比，所有BAV患者的非扩张和扩张主动脉壁中的血管平滑肌细胞均具有成熟缺陷，这可能导致内在的发育易感性。除血管壁结构异常外，二叶式瓣膜几何形状引起的血流紊乱会加速主动脉壁的病理过程，导致主动脉病变。尽管主动脉病变的风险很大，但并非所有BAV患者在其一生中都会经历（急性）主动脉并发症，这突出了发病过程的复杂性。最近的研究集中在半月瓣和升主动脉壁的胚胎发育上。他们的发现突出表明，胚胎发生缺陷不仅可以解释畸形主动脉瓣的形成，还可以解释升主动脉和主动脉弓病变风险增加的原因。本综述概述了主动脉瓣和主动脉壁的正常及异常发育：早期胚胎发生中的常见缺陷会导致BAV及相关主动脉病变的发生。
