Isolated abdominal aortic tortuosity diagnosed by fetal echocardiography

Abstract

Arterial tortuosity syndrome (ATS) is a rare, autosomal recessive, connective-tissue disorder associated with elongation, tortuosity, stenosis, and aneurysms of the large and mid-sized arteries [1]. The symptoms of ATS, such as severe neonatal hypertension [2], can be potentially critical, and close monitoring and extensive vascular imaging are warranted [3]. Although fetal diagnosis of ATS [4] is clinically relevant, it has been rarely reported. We report a case of isolated abdominal aortic tortuosity (iAAT), similar to AAT in ATS, diagnosed by fetal echocardiography. A 36-year-old, 1 gravida 0 para woman with unremarkable medical and family histories was referred to our center at 28 weeks 3 days of gestation for a detailed evaluation for AAT. Fetal ultrasonography revealed normal growth and no other cardiovascular abnormalities. Longitudinal views of two-dimensional fetal echocardiograms revealed a gap between the parallel paths of the thoracic and abdominal aorta (Fig. 1A-1, A-2, Online Animation 1, 2), which is not observed in normal conditions. By sweeping a transducer, we identified that the thoracic aorta descended along a straight left-sided path, while the abdominal aorta turned by > 180° at the infradiaphragmatic level (Fig. 1B-1, B-2). No abdominal aortic stenosis, dilation, or aneurysm was observed, and the lower abdominal aortic flow pattern was normal. Three-dimensional echocardiography clearly revealed aortic tortuosity (Fig. 1C). We tentatively diagnosed the fetus with iAAT. A female infant weighing 2895 g was born at a gestational age of 38 weeks and 6 days with an Apgar score of 8–9. We did not observe any physical abnormality. Her general condition remained fine with good pulsation and perfusion of the lower extremity. Postnatal enhanced computed tomography (CT) at 1 and 21 months (Fig. 1D, E, respectively) confirmed the diagnosis of fetal iAAT made using fetal echocardiography. The infant remained healthy without any symptoms up to 2 years. Genetic testing for ACTA2/MYH11/MYLK/ TGFBRl/TGFBR2/SLC2Al0/COL3Al/EFEMP2/FBN1/ FBN2/FLNA/SMAD3/TGFB2/TGFB3 revealed no mutation in the SLC2A10 gene, which is responsible for ATS, but revealed an unreported mutation in the MYLK gene (MYLK(NM_053025.3):c.1652-4A > G(rs1463457258)) although its pathogenetic significance remains unclear. AAT initiates prenatally in some cases and can be diagnosed by fetal echocardiography [4]. Fetal long-axis views may provide the following clues for diagnosing AAT: a gap between the thoracic and abdominal aortic paths and AAT revealed by sweeping a transducer. Accumulation of information from additional cases of fetal AAT is needed to clarify the long-term changes in the arterial tree structure from the fetal period. Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s1257 4-019-00441 -0) contains supplementary material, which is available to authorized users.