The Relationship Between Somatic Growth and In Vivo Esophageal Segmental and Sphincteric Growth in Human Neonates

Background: Measurement of aerodigestive tract length is an important determinant for accurate placement of esophageal probes and gavage tubes at the desired location. The relationship of esophageal body, upper esophageal sphincter (UES) and lower esophageal sphincter (LES) lengths with somatic growth in neonates is not well understood. Objectives: Our objectives were to (1) evaluate a relationship between segmental esophageal lengths and somatic growth parameters and (2) ascertain the relationship between segmental esophageal lengths and gestational age (GA) and postmenstrual age (PMA) in preterm and full‐term born human neonates. Design/Methods: One hundred esophageal manometry studies were performed in 75 infants (30‐60 weeks PMA) and the high‐pressure zones of LES and UES identified. The distance from nares to LES and from nares to UES, esophageal body length, length of UES and LES derived from the manometry studies were correlated with somatic growth parameters. Growth rate of different esophageal segments was also determined in 26 subjects that underwent longitudinal studies. Analysis of variance and linear regression analysis were performed. Results: Seventy‐five neonates of 23.0‐40.6 weeks gestational age (0.6‐4.4 kg) were studied at 29.1‐58.6 weeks PMA (1.0‐6.4 kg). Significant correlation ( P < 0.001) of PMA and physical growth parameters with the growth of nares‐LES ( R 2 = 0.8), esophageal body length ( R 2 = 0.6) and nares‐UES ( R 2 = 0.4) were noted. Nares‐to‐LES length increased at a rate of 0.25 cm/wk PMA during 33.0‐36.0 weeks of age. Conclusions: In vivo esophageal segmental lengths correlated strongly with somatic growth parameters and PMA in neonates. We speculate that this approach has many practical applications with the use of esophageal probes and catheters.