Topographicalplotsofesophagealdistensionandcontraction:effectsofpostureonesophageal peristalsisandbolustransport

Abstract

Each swallow induces a wave of inhibition followed bycontractionin the esophagus. Unlikecontraction, which can easily be measured in humans using high-resolution manometry (HRM), inhibition is difficult to measure. Luminaldistensionis a surrogate of theesophagealinhibition. The aim of this study was to determine the effect ofpostureon the temporal and quantitative relationship betweendistensionandcontractionalong the entire length of the esophagus in normal healthy subjects by using concurrent HRM, HRM impedance (HRMZ), and intraluminal ultrasound (US). Studies were conducted in 15 normal healthy subjects in the supine and Trendelenburg positions. Both manual and automated methods were used to extract quantitative pressure and impedance-derived features from the HRMZ recordings.Topographicalplotsofdistensionandcontractionwere visualized along the entire length of the esophagus.Distensionwas also measured from the US images during 10-ml swallows at 5 cm above the loweresophagealsphincter. Each swallow was associated with luminaldistensionfollowed bycontraction, both of which traversed the esophagus in a sequential/peristaltic fashion. Luminaldistension(US) andesophagealcontractionamplitude were greater in the Trendelenburg compared with the supine position. Length ofesophagealbreaks (in the transition zone) were reduced in the Trendelenburg position. Change inposturealtered the temporal relationship betweendistensionandcontraction, andbolustraveled closer to theesophagealcontractionin the Trendelenburg position.Topographicalcontraction-distensionplotsderived from HRMZ recordings is a novel way to visualizeesophagealperistalsis. Future studies should investigate if abnormalities ofesophagealdistensionare the cause of functional dysphagia. NEW & NOTEWORTHY Ascendingcontractionand descending inhibition are two important components ofperistalsis. High-resolution manometry only measures thecontractionphase ofperistalsis. We measuredesophagealdistensionfrom intraluminal impedance recordings and developed novelcontraction-distensiontopographicalplotsto prove that similar tocontraction,distensionalso travels in a peristaltic fashion. Change inposturefrom the supine to the Trendelenburg position also increased the amplitude ofesophagealdistensionandcontractionand altered the temporal relationship betweendistensionandcontraction.