ABSTRACT
Each swallow induces a wave of inhibition followed by contraction in the esophagus. Unlike contraction, which can easily be measured in humans using high-resolution manometry (HRM), inhibition is difficult to measure. Luminal distension is a surrogate of the esophageal inhibition. The aim of this study was to determine the effect of posture on the temporal and quantitative relationship between distension and contraction along 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. Topographical plots of distension and contraction were visualized along the entire length of the esophagus. Distension was also measured from the US images during 10-ml swallows at 5 cm above the lower esophageal sphincter. Each swallow was associated with luminal distension followed by contraction, both of which traversed the esophagus in a sequential/peristaltic fashion. Luminal distension (US) and esophageal contraction amplitude were greater in the Trendelenburg compared with the supine position. Length of esophageal breaks (in the transition zone) were reduced in the Trendelenburg position. Change in posture altered the temporal relationship between distension and contraction, and bolus traveled closer to the esophageal contraction in the Trendelenburg position. Topographical contraction-distension plots derived from HRMZ recordings is a novel way to visualize esophageal peristalsis. Future studies should investigate if abnormalities of esophageal distension are the cause of functional dysphagia. NEW & NOTEWORTHY Ascending contraction and descending inhibition are two important components of peristalsis. High-resolution manometry only measures the contraction phase of peristalsis. We measured esophageal distension from intraluminal impedance recordings and developed novel contraction-distension topographical plots to prove that similar to contraction, distension also travels in a peristaltic fashion. Change in posture from the supine to the Trendelenburg position also increased the amplitude of esophageal distension and contraction and altered the temporal relationship between distension and contraction.
