Esophageal Motility in the Human Neonate

Abstract

After reading this article, readers should be able to: 1. Describe the developmental physiology of esophageal motility. 2. Understand the primary and secondary patterns of esophageal peristalsis. 3. Describe the functions of the upper and lower esophageal sphincters during esophageal bolus transit. The incidence of concomitant feeding and airway-related disorders is high among preterm infants, sick term infants, and infants who have congenital foregut anomalies. Although the lung bud is an offshoot of the primitive foregut, the effects of airway disease on swallowing or gastroesophageal reflux disease and vice versa remain unclear. The esophagus may function merely as a conduit tube between the oropharynx and stomach, but its physiology is complex, belying that simple role. The neonatal literature is replete with controversies pertinent to aerodigestive tract diseases and their management. This article focuses on recent thinking regarding the physiology of neonatal esophageal motility from the standpoint of both basic and clinical science. At 4 weeks of embryonic life, tracheal diverticulum appears at the ventral wall of the foregut, with the left vagus being anterior and right vagus posterior in position. At this stage of development, the stomach is a fusiform tube in which the dorsal side growth rate is greater than ventral side rate, creating greater and lesser curvatures. Embryologically, the airway and lung buds, pharynx, esophagus, stomach, and diaphragm are derived from the primitive foregut and or its mesenchyme and share similar control systems. (1)(2)(3) At 7 weeks of embryonic life, the stomach rotates 90 degrees clockwise, displacing the greater curvature to the left. The left vagus innervates the stomach anteriorly and right vagus innervates the posterior aspect of stomach. At 10 weeks, the esophagus and stomach are in the proper position, and circular and longitudinal muscle layers and ganglion cells are in place. Swallowing ability develops by …