Gastroesophageal Reflux 2D and 3D Steady State CFD Simulations

Gastro-Esophageal Reflux Disease (GERD) is a condition which affects up to 20% of the adult US population on a weekly basis. It is a condition where acid is allowed to flow from the stomach and into the esophagus where it causes damage to the local tissue. In chronic cases the condition can lead to cancer. Dysfunction of the Esophagogastric Junction is indicated as a primary cause. The recently developed Functional Lumen Imaging Probe (FLIP) is designed for assessment of the EGJ. It measures the cross sectional area at eight locations through the junction. This data has been used to construct a series of computational fluid dynamic simulations. These simulations showed a jet of fluid which squirts into the esophagus under the gastric pressure. This jet corresponds with previously gathered anecdotal evidence. The centerline velocities of this jet were measured and this suggested that the jet could travel up to 20 times the minimum diameter of the EGJ into the esophagus before decelerating to 25% of its original velocity. This means that if an EGJ was curved then this jet could impinge on the walls causing a localized area of increased damage to the mucosa compared to the surrounding tissue.