# Preliminary Characterization of Proximal Versus Distal Esophageal Function in Healthy, Asymptomatic Adults

## TL;DR

This study measures normal esophageal function in healthy adults using a new method to compare upper and lower esophageal pressures in different body positions.

## Contribution

The paper introduces the first quantification of normal proximal esophageal function using high-resolution manometry in both supine and upright positions.

## Key findings

- Proximal esophageal pressures and contraction times differ significantly between supine and upright positions.
- Distal esophageal measurements fell within normal ranges, while proximal measurements showed statistical differences.
- This is the first study to use HRM to measure proximal esophageal function in two body positions.

## Abstract

The reference standard for the assessment of esophageal motility and sphincter function is high‐resolution esophageal manometry (HRM). Diagnostic values for HRM are determined by the Chicago Classification (CC v4.0), which is based almost entirely on distal esophageal function without measures to address the proximal esophageal segment. Therefore, we sought to determine normal HRM values for proximal esophageal function when obtained in the standard HRM positions (supine and upright).

Healthy, asymptomatic adults (≥ 18 years) were recruited. All participants completed a standard protocol. CC v4.0 measurements, along with a proximal contractile integral (PCI) (millimeters mercury‐seconds‐centimeters[mmHg‐s‐cm]), temporal measures of proximal and distal contractility (seconds), and lengths of proximal and distal esophagus (centimeters), were performed. Summary statistics, tests of normality, and paired two‐sided t‐tests were performed.

HRM data from 30 participants were included. Mean supine PCI was 423.9 mmHg‐s‐cm with a mean contraction time of 3.2 s and a mean length of 5.5 cm. The mean upright PCI was 183.9 mmHg‐s‐cm with a mean contraction time of 2.2 s, and a mean length of 4.5 cm. All proximal values were significantly different comparing the two positions (PCI p < 0.0001; time p < 0.0001; length p < 0.0001). All distal measurements fell within the ranges of normal, and all measures for contractile integral, contraction time, and contraction length were statistically significantly different (p < 0.0001 for all) comparing proximal versus distal measurements.

These preliminary data represent our first attempt to quantify normal proximal esophageal function using HRM measurements of contractile vigor, contraction length, and time.

Swallowing pressures in the upper 1/3 (proximal) and lower 2/3rd (distal) esophagus are impacted in seated compared to laying down.This article is the first attempt to measure these different pressures using a catheter inserted through the nose and into the esophagus and stomach using a technology called High‐Resolution Esophageal Manometry.

Swallowing pressures in the upper 1/3 (proximal) and lower 2/3rd (distal) esophagus are impacted in seated compared to laying down.

This article is the first attempt to measure these different pressures using a catheter inserted through the nose and into the esophagus and stomach using a technology called High‐Resolution Esophageal Manometry.

The preliminary data represent the first attempt to quantify normal proximal esophageal function using HRM pressure and temporal contractility measurements in two positions. All proximal values (PCI, contraction time, and contraction length) were significantly different when comparing the two positions (PCI p < 0.0001; time p < 0.0001; length p < 0.0001).