PEDIATRIC GASTROENTEROLOGY, HEPATOLOGY & NUTRITION Esophageal Bolus Transit in Newborns with Gastroesophageal Reflux Disease Symptoms: A Multichannel Intraluminal Impedance Study

Purpose: The aim of this study was to evaluate bolus transit during esophageal swallow (ES) and gastroesophageal reflux (GER) events and to investigate the relationship between the characteristics of ES and GER events in a pop-ulation of term and preterm newborns with symptoms of gastroesophageal reflux disease (GERD). Methods: The study population consisted of term and preterm newborns referred to combined multichannel intra-luminal impedance (MII) and pH monitoring for GERD symptoms. The frequency and characteristics of ES and GER events were assessed by two independent investigators. Statistical significance was set at p＜0.05. Results: Fifty-four newborns (23 preterm) were included in the analyses. Median bolus head advancing time cor-rected for esophageal length (BHATc) was shorter during mealtime than during the postprandial period (median, interquartile range): 0.20 (0.15-0.29) s/cm vs. 0.47 (0.39-0.64) s/cm, p＜0.001. Median bolus presence time (BPT) was prolonged during mealtime: 4.71(3.49-6.27) s vs. 2.66 (1.82-3.73) s, p＜0.001. Higher BHATc (p=0.03) and prolonged BPT (p＜0.001) were observed in preterm newborns during the postprandial period. A significant positive correlation between BHATc and bolus clearance time was also observed (ρ=0.33, p=0.016). Conclusion: The analysis of ES and GER events at the same time by MII provides useful information to better under-stand the physiopathology of GERD. In particular, the analysis of BHATc during the postprandial period could help clinicians identify newborns with prolonged esophageal clearance time due to impaired esophageal motility, whic