Characterization of esophageal body and lower esophageal sphincter motor function in the very premature neonate

Objectives: To characterize esophageal body and lower esophageal sphincter (LES) motor function in very premature infants. Study design: Esophageal manometry was performed in 12 very premature infan ts of 26 to 33 weeks' postmenstrual age (PMA) (body weights of 610-1360 g). Esophageal motor patterns were recorded for 30 minutes with a perfused mic romanometric sleeve assembly (outer diameter, 2.0 mm). Results: Esophageal pressure waves triggered by dry swallows were predomina ntly (84%) peristaltic in propagation sequence. All infants showed tonic LE S contraction; the mean resting LES pressure (LESP) for individual infants ranged from 5.0 +/- 4.1 mm Hg to 20.0 +/- 4.8 mm Hg. In all infants the LES relaxed (duration, 5.8 +/- 3.0 seconds; nadir pressure, 1.8 +/- 2.6 mm Hg) in response to pharyngeal swallows. Transient LES relaxations (TLESRs) (du ration, 21.7 +/- 8.7 seconds; nadir pressure, 0.1 +/- 1.8 mm Hg) occurred o n average 2.6 +/- 1.6 times per study; 86% of these relaxations triggered e sophageal body common cavity events known to be associated with gastroesoph ageal reflux. Conclusions: Esophageal motor function is well developed in very premature infants. Our data also suggest that TLESR is the predominant mechanism of r eflux in these babies.