背景:孤立的左锁骨下动脉(ILSA)的发生相对罕见,ILSA是由第六左弓的背节持续引起的,胚胎发育过程中,第四弓动脉消退,左侧第七节间动脉远端左背主动脉中断。左锁骨下动脉通过动脉导管与肺动脉相连,可以关闭或通畅。这种异常可导致先天性锁骨下动脉盗血综合征和椎基底动脉供血不足。
方法:我们报道了3例患有ILSA和心内畸形的胎儿。其中,1例疑似通过超声心动图诊断为ILSA,而另外两例没有确诊,但在尸检时被意外发现.我们还对其产前筛查进行了文献综述,诊断,管理,和结果。我们的三个病例通过WES-Trio(全外显子组测序)进行了测试。全球,英国文献报道的ILSA病例尚未被WES检测到。在我们的两个病例中发现了可能的致病结果。虽然不能解释我们发现的心内畸形,这将有助于将来探索病因。
结论:产前超声心动图检测和诊断ILSA是一项新的挑战,对胎儿的预后有不同的影响。当发现右主动脉弓的心内畸形时,我们需要进行非常规的超声扫描,并结合CDFI来找到左锁骨下动脉的起源。虽然暂时找不到病因,但是我们的遗传结果可以帮助产前遗传咨询。
BACKGROUND: The occurrence of Isolated left subclavian artery (ILSA) is relatively rare, ILSA is caused by the persistence of the dorsal segment of the sixth left arch, with regression of the fourth arch artery and interruption of the left dorsal aorta at the distal end of the seventh intersegmental artery on the left side during embryonic development. The left subclavian artery is connected to the pulmonary artery through an arterial duct, which can be closed or unobstructed. This abnormality can lead to congenital subclavian steal syndrome and vertebrobasilar artery insufficiency.
METHODS: We reported three fetuses with ILSA and intracardiac malformation. Among them, one case was suspected to be diagnosed with ILSA by echocardiography, while the other two cases were not diagnosed, but were accidentally discovered during autopsy. We have also conducted a literature review of its prenatal screening, diagnosis, management, and outcomes. Our three cases were tested by WES-Trio (whole exome sequencing). Worldwide, the ILSA cases reported in English literature have not been detected by WES. And likely pathogenic results were found in our two cases. Although it could not explain the intracardiac malformation we found, it will help to explore the etiology in the future.
CONCLUSIONS: Prenatal echocardiography detection and diagnosis of ILSA is a new challenge, which has different effects on the prognosis of the fetus. When finding intracardiac malformation with right aortic arch, we need to perform an unconventional view of ultrasound scanning and combine with CDFI to find the origin of the left subclavian artery. Although we cannot find the cause of the disease temporarily, but our genetic results can help prenatal genetic counseling.