Feasiblity Study on the Longitudinal Section of the Fetal Esophagus by Prenatal Ultrasound between 21 and 23 Gestational Weeks

Abstract

Background: Prenatal esophageal atresia (EA) diagnosis may improve outcomes by optimizing prenatal and postnatal care. This study evaluated the feasibility of direct antenatal visualization of normal longitudinal esophageal sections using two-dimensional ultrasound between 21 and 23 gestational weeks. Methods: A detailed prenatal anatomic survey was performed, followed by dedicated esophageal imaging. The latter was performed as follows: coronal sections of the thoracic aorta were obtained; the sound beam was then moved ventrally; and strip-shaped high echoes with three or more hyperechoic layers were identified as the esophagus. Images showing the longest esophageal segment were used to measure the esophageal length and angle (between the thoracic aorta and esophagus). Results: Longitudinal esophageal sections were visualized in 94.0% (n = 205/218) of patients. The visualization rates between fetuses in different positions were statistically significant (p < 0.05). Two tubular patterns of longitudinal fetal esophagus sections were observed when collapsed on ultrasound: a tubular structure composed of three hyperechoic layers (40.4%, 88/218); and a tube composed of multilayered hyperechoic structures (59.6%, 130/218). Swallowing actions were observed in 28 cases (12.8%, 28/218). The fetal esophagus was fluid-filled and exhibited an appearance similar to a tram-track sign. The time taken to visualize the longitudinal esophageal section was 21.3 ± 13.1 sec (range 3–60 sec). Conclusions: Direct antenatal visualization of a normal fetal esophagus is feasible, and recommended when suspecting EA on routine fetal ultrasound, to improve diagnostic specificity.

Keywords

• longitudinal section
• fetal esophagus
• prenatal ultrasound