Endoscopic and Manometric Characteristics of the Gastroesophageal Valve in Lateral Decubitus and Upright Positions in Clinically Normal Patients

Background: The relationship between body position and the gastroesophageal junction (GEJ) has been subject to intense interest in its role in gastroesophageal reflux disease (GERD). Few studies have looked at the position related changes of the gastroesophageal valve (GEV) in asymptomatic individuals.
Purpose: To define the normal physiology of the GEJ in left lateral decubitus (LLD) and upright position in asymptomatic individuals.
Methods: Ten healthy asymptomatic volunteers with no previous history of GERD confirmed by 2 validated GERD questionnaires were studied. Subjects underwent high resolution manometry in both LLD and upright positions. Following this, upper endoscopy was performed in the same two positions with detailed observation and grading of the GEV according to Hill (Grade 1–4; 1=normal closed valve, 4=open valve, associated hiatus hernia). A Medtronic 48 hour pH probe was placed 6 cm above the endoscopic GEV at the completion of the endoscopy.
Results: All volunteers completed the three investigations in two positions. Mean age 27 years. Four out of 10 patients were noted to have abnormal 48 hour pH studies (DeMeester score >15). No hiatus hernias were noted in any patients. Endoscopically, there was an overall increase in mean Hill Grade when patients were moved from LLD to upright position (1.6, 2.3, p=0.001, respectively), with no significant differences between normal and abnormal pH patients. In the abnormal pH group, on endoscopy 75% were found to have prolonged transient opening of the GEV on passive retroflexed observation in LLD position, compared with 16.7% of normal pts (p=0.1). This was not observed in upright position. Manometrically, this was correlated with a non significant trend toward lower mean LES resting pressure and shorter intra-abdominal LES length for the abnormal pH patients in all positions compared to normals.
Conclusions: In general, the endoscopic Hill grade of the GEV does not correlate with the manometric findings in either LLD or upright positions. However, endoscopic observation of transient GEV opening in LLD position may be due to shortening of the intra-abdominal LES and may predict early stages of GERD. High resolution manometric findings are better predictors of early GERD, with a shorter and weaker LES in abnormal pH patients compared to normals. Further research of the baseline anatomic and physiologic changes of the LES related to position may help to better the earliest changes in the development of GERD.

Session: Podium Presentation

Program Number: S106

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