Pathophysiology of Gastroesophageal Reflux Disease and Hiatal Hernia

The role of hiatus hernia in the pathophysiology of gastro-esophageal reflux has recently been reevaluated. In particular, the correlation between hiatus hernia and higher degrees of gastro-esophageal reflux has been demonstrated. A) The LES pressure is the result of the superimposition of the two branches of the right pillar of the diaphragmatic hiatus to the intrinsic sphincteric area localized in the distal esophagus and proximal stomach. The loss of synergy between the intrinsic and the extrinsic components of the gastro-esophageal junction caused by hiatus hernia impairs the mechanical properties of the gastro–esophageal barrier. In the case of orad migration of the gastro-esophageal junction above the diaphragm, the increases of intra-abdominal pressure do not correspond to equal increases of the pressure the LES complex because the diaphragmatic pinchcock does not strengthen the intrinsic sphincter and the lower esophagus is influenced by the negative intrathoracic pressure and not by the increased intra-abdominal pressure. B )Axial hiatus hernias, characterized by the permanent supradiaphragmatic position of the gastro-esophageal junction and not the more common sliding hiatus hernia, are associated with severe gastro-esophageal reflux disease. The distance between the gastro-esophageal junction and the diaphragm and not the size of the hernia per se influences the degree of cardial incontinence and the severity of gastro-esophageal reflux disease. C ) When cardial incontinence is caused by a significant anatomical disorder such as in the case of the permanent axial migration of the gastro-esophageal junction across or above the diaphragm, it is reasonable to add this condition, if it is associated with severe and persistent gastro-esophageal reflux disease, to the list of indications for anti-reflux surgery. D) The barium swallow is again essential for the preoperative work up: it alerts the patient and surgeon to the possibility of facing a case in which a more complex technique such as the Collis gastroplasty could be required if the radiological orad migration of the gastro-esophageal junction corresponds to a true short esophagus. This awareness is crucial in order to illustrate properly to the patient the risks of surgery and the expected results and to plan the operation.