Читать книгу The Esophagus - Группа авторов - Страница 148

The diaphragm contributes to LES pressure and especially to antireflux barrier function [281, 389]. The crural diaphragm coordinates with LES relaxation during swallowing and with TLESRs [383, 390]. A hiatus hernia separates the contribution of the diaphragm to the antireflux barrier function, the hernia acting as one contributing factor to gastroesophageal reflux. Using HRM, morphology of the EGJ has been categorized into three subtypes based on the relationship between the crural diaphragm and the intrinsic LES: type 1, where diaphragm and LES are superimposed; type 2, where separation is 2 cm or less; and type 3, where separation is 3 cm or higher [391]. These EGJ morphology phenotypes demonstrate an increasing gradient of esophageal acid exposure as separation increases between the intrinsic LES and the crural diaphragm [392, 393].