The phrenoesophageal ligament (phrenoesophageal membrane) is a fibro-elastic connective tissue band attaching the oesophagus to the margins of the oesophageal hiatus in the diaphragm. It consists of an upper leaf that attaches to the oesophagus 2-4 cm above the hiatus and a lower leaf that attaches below the hiatus. It allows the oesophagus to slide 2-3 cm up and down with swallowing while maintaining a functional seal at the gastroesophageal junction.
Anchors the gastroesophageal junction in its normal subdiaphragmatic position, maintains the lower oesophageal sphincter below the diaphragm (preserving the extrinsic crural compression component of the LOS), and allows physiological sliding of the oesophagus during swallowing.
Attenuation and stretching of the phrenoesophageal ligament is the primary mechanism allowing sliding hiatal hernia formation, where the gastroesophageal junction migrates above the diaphragm. Loss of the crural compression normally provided by the hiatus around the oesophagus, and repositioning of the LOS above the positive-pressure abdominal cavity, both contribute to gastroesophageal reflux disease. Laparoscopic fundoplication and hiatal hernia repair restore the phrenoesophageal anatomy by returning the GEJ below the diaphragm and repairing the hiatal defect.
Age-related attenuation and elevated intra-abdominal pressure progressively stretch the phrenoesophageal ligament, allowing the gastroesophageal junction to herniate above the diaphragm into the posterior mediastinum, producing the sliding hiatal hernia with gastroesophageal reflux managed by proton pump inhibitors and laparoscopic fundoplication for symptomatic cases.
