Demographic Factors in Pharyngoesophageal Segment Size: A Scoping Review

The Pharyngoesophageal Segment (PES) is situated at the junction of the pharynx and esophagus, regulating the passage of bolus from the pharynx into the esophagus during swallowing and preventing aspiration into the airway. Decreased opening of this sphincter can result in significant swallow impairment. Knowledge of normal PES size can be critical for diagnostic purposes and treatment planning. This systematic review seeks to aggregate the evidence correlating PES size with demographic factors, including age, sex, and obesity status.

A search performed on PubMed, Embase, Cochrane, and Ovid included literature published before August 18, 2025.

Inclusion criteria were healthy adult populations (including cadavers). Publications investigating only animal, pediatric, or pathologic populations or that did not include demographic comparisons were excluded.

A total of 5815 studies were retrieved, and 679 subjects across 10 studies met the inclusion criteria. Diverse parameters were measured, including PES area, diameter, lateral diameter, and anterior-posterior diameter. With varying parameters, different bolus sizes, and few papers, conclusive findings on PES size were not found. Studies that reported the mean size for each demographic group recorded a greater male PES size than female. The data conflicted regarding a greater PES size in elderly or non-elderly populations. Mean data regarding obesity and height were not reported but were noted not to significantly impact PES size.

Many research gaps exist in defining normal PES size. Further research is needed to better elucidate issues like age-related differences, as well as measurement parameters and techniques.