Esophageal hiatus

The esophageal hiatus is an opening in the muscular part of the diaphragm. It is located at the vertebral level T10 and lies slightly to the left of the midline.

The esophagus is the principal structure passing through the esophageal hiatus as it continues from the thorax into the abdomen to join the stomach. Accompanying the esophagus through this opening are the anterior and posterior vagal trunks, oesophageal branches of the left gastric vessels, and lymphatic vessels.

Unlike the aortic hiatus, the esophageal hiatus is surrounded by muscular fibres of the diaphragm. Anatomically, the esophageal hiatus lies anterior to the aortic hiatus and superior to the central tendon of the diaphragm. During inspiration, contraction of the diaphragmatic muscle fibres exerts a sphincter-like effect around the oesophagus, contributing to the prevention of gastroesophageal reflux. This physiological mechanism complements the action of the lower oesophageal sphincter. Weakness or enlargement of this opening may lead to a hiatal hernia, in which part of the stomach protrudes into the thoracic cavity.