Characterization of esophageal body and lower esophageal sphincter motor function in the very premature neonate.
OBJECTIVE
To characterize esophageal body and lower esophageal sphincter (LES) motor function in very premature infants.


METHODS
Esophageal manometry was performed in 12 very premature infants 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 micromanometric sleeve assembly (outer diameter, 2.0 mm).


RESULTS
Esophageal pressure waves triggered by dry swallows were predominantly (84%) peristaltic in propagation sequence. All infants showed tonic LES 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) (duration, 21.7 +/- 8.7 seconds; nadir pressure, 0.1 +/- 1.8 mm Hg) occurred on average 2.6 +/- 1.6 times per study; 86% of these relaxations triggered esophageal body common cavity events known to be associated with gastroesophageal reflux.


CONCLUSIONS
Esophageal motor function is well developed in very premature infants. Our data also suggest that TLESR is the predominant mechanism of reflux in these babies.
Omari
T I
TI
Gastroenterology Unit, Women's and Children's Hospital, North Adelaide, Australia.
Benninga
M A
MA
Barnett
C P
CP
Haslam
R R
RR
Davidson
G P
GP
Dent
J
J
D004943:Esophagogastric Junction / Q000502:physiology; D004947:Esophagus / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D019102:Infant, Very Low Birth Weight; D008365:Manometry; D009119:Muscle Contraction; D010528:Peristalsis; D011312:Pressure