The fetal esophagus: anatomical and physiological ultrasonographic characterization using a high‐resolution linear transducer

Abstract

Objective To study the sonographic anatomy and physiology of the human fetal esophagus during the mid-trimester of pregnancy using a high-resolution linear transducer. Methods

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“…Transient relaxations of the lower esophageal sphincter, independent of swallowing and lasting for 3.2–30 s, have been reported in preterm infants (28–36 gestational weeks)9. This is in line with our observation of frequent and long lasting fluid‐filling of E2, and also with ultrasound studies reporting no Doppler signals within the fluid‐filled esophagus1, 2.…”

“…Although this study was retrospective in nature and the MRI examinations were not devoted to visualizing the esophagus, we obtained similar results with respect to visualization of segment E2 as have prospective ultrasound studies1, 2. However, ultrasound is superior in visualizing esophageal segment E1 before 26 gestational weeks2, while we believe that MRI seems to be better afterwards. Furthermore, we also observed the simultaneous opening of the whole fetal esophageal lumen, as reported sonographically in 19–26‐week fetuses2, in third‐trimester fetuses.…”

“…However, ultrasound is superior in visualizing esophageal segment E1 before 26 gestational weeks2, while we believe that MRI seems to be better afterwards. Furthermore, we also observed the simultaneous opening of the whole fetal esophageal lumen, as reported sonographically in 19–26‐week fetuses2, in third‐trimester fetuses.…”

“…While the normal fetal esophagus has been studied with ultrasound1, 2, and fetal magnetic resonance imaging (MRI) has been used in cases of esophageal atresia3–6, there has been no systematic MRI study of the fetal esophagus. Previous studies using MRI found the esophagus difficult to visualize7 or it was observed infrequently8.…”

Esophageal obstruction—prenatal detection rate and outcome

“…It is possible to visualize the normal fetal esophagus during the first trimester27 and the esophagus can be detected in approximately 90% of normal fetuses in the second and third trimesters28, 29. Although prenatal diagnosis of esophageal atresia had already been described in the early 1980s11, 30, 31, the rate of prenatal detection has been reported to be low (9–42%)2, 7, 9, 10, 32 and the diagnosis is usually not made before the third trimester.…”