Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
Ultrasound Obstet Gynecol. 2010 Nov;36(5):548-52. doi: 10.1002/uog.7683.
This study was carried out to determine the feasibility of defining the position of the right subclavian artery (RSA) by fetal echocardiography between 16 and 23 weeks of gestation, and the association between an aberrant right subclavian artery (ARSA) and chromosomal and cardiac defects.
We examined the position of the RSA in all patients who attended our unit for a fetal cardiac scan. The assessment was carried out using a transverse view of the fetal chest sweeping up from the level of the aortic arch, using color flow mapping. An ARSA was diagnosed when this vessel was not seen in the normal position and an arterial vessel was seen crossing behind the trachea towards the right arm, arising as a fourth branch of the aortic arch, at a lower level than normal.
The course of the RSA could be identified in more than 95% of the 2799 fetuses examined between 16 and 23 + 6 weeks of gestation. An ARSA was found in 43 fetuses. The incidence was 1.5% in normal fetuses, 28.6% in fetuses with trisomy 21, 18.2% in fetuses with trisomy 18 and 8% in fetuses with other chromosomal defects. There was an association between an ARSA and cardiac defects in seven of the 43 fetuses (16%), and three of these seven fetuses had a normal karyotype.
Assessment of the RSA by a fetal cardiologist is possible in almost all cases. The finding of an ARSA is much more common in fetuses with chromosomal defects, in particular trisomy 21 (where the prevalence of an ARSA was 29%), compared with euploid fetuses. Moreover, the presence of an ARSA may be associated with an increased incidence of intracardiac malformations. Examination of the position of the RSA is likely to become a routine ultrasound marker for chromosomal abnormalities in the second trimester of pregnancy.
本研究旨在确定在 16 至 23 孕周通过胎儿超声心动图定义右锁骨下动脉（RSA）位置的可行性，以及异常右锁骨下动脉（ARSA）与染色体和心脏缺陷之间的关系。
我们检查了所有在我们单位进行胎儿心脏扫描的患者的 RSA 位置。使用从主动脉弓水平向上的胎儿胸部横切面进行评估，使用彩色血流映射。当未在正常位置看到该血管并且看到一条动脉血管穿过气管向右臂时，诊断为 ARSA，该动脉血管在较低水平处作为主动脉弓的第四分支出现。
在 16 至 23+6 孕周的 2799 例胎儿中，超过 95%的胎儿可以识别 RSA 的走行。在 43 例胎儿中发现了 ARSA。在正常胎儿中发生率为 1.5%，在 21 三体胎儿中为 28.6%，在 18 三体胎儿中为 18.2%，在其他染色体缺陷胎儿中为 8%。在 43 例胎儿中有 7 例（16%）存在 ARSA 与心脏缺陷之间的关联，其中 7 例中有 3 例具有正常核型。
胎儿心脏病专家对 RSA 的评估几乎在所有情况下都是可行的。在染色体缺陷的胎儿中，特别是在 21 三体（ARSA 的患病率为 29%）中，ARSA 的发现更为常见与正常胎儿相比。此外，ARSA 的存在可能与心脏畸形的发生率增加有关。在妊娠中期，检查 RSA 的位置可能成为染色体异常的常规超声标志物。
