Esophageal Hiatus

The esophageal hiatus is an opening in the diaphragm through which the esophagus passes from the thoracic cavity into the abdominal cavity. It is located in the muscular part of the diaphragm and also transmits the anterior and posterior vagal trunks, as well as small esophageal blood vessels and lymphatics. This hiatus plays an important role in maintaining the competence of the gastroesophageal junction and preventing reflux.

Location

• Vertebral level: T10
• Position: In the muscular portion of the diaphragm, slightly to the left of the midline

Structures Passing Through

• Esophagus
• Anterior vagal trunk (mainly from the left vagus nerve)
• Posterior vagal trunk (mainly from the right vagus nerve)
• Esophageal branches of the left gastric artery and vein
• Lymphatic vessels

Muscular Composition

The esophageal hiatus is formed by the right crus of the diaphragm. Fibers from the right crus loop around the esophagus, creating a sphincter-like mechanism that contributes to the prevention of gastroesophageal reflux. These muscle fibers act in coordination with the lower esophageal sphincter (LES) and intra-abdominal pressure to maintain closure of the gastroesophageal junction.

Function

• Allows passage of the esophagus and associated structures between the thorax and abdomen
• Contributes to the anti-reflux barrier at the gastroesophageal junction
• Contracts during inspiration and increased intra-abdominal pressure to help maintain LES competence

Relations

• Anterior: Pericardium and heart
• Posterior: Vertebral bodies and thoracic aorta
• Right: Right crus of the diaphragm
• Left: Fundus of the stomach (below)

Clinical Significance

• Hiatal hernia: Weakness or widening of the esophageal hiatus can allow part of the stomach to herniate into the thorax, leading to reflux and discomfort
• Gastroesophageal reflux disease (GERD): Dysfunction of the hiatus or surrounding diaphragm can compromise the anti-reflux barrier
• Surgical landmark: During fundoplication or esophagectomy, the hiatus is a key anatomical feature

Associated Sphincter Mechanism

The esophageal hiatus, lower esophageal sphincter (LES), and diaphragmatic crura together form a functional sphincter. This barrier helps prevent the regurgitation of gastric contents into the esophagus, especially during changes in intra-abdominal pressure such as coughing, bending, or straining.

Topographic Summary

• Location: T10 vertebral level, left of midline
• Formed by: Right crus of the diaphragm
• Transmits: Esophagus, vagal trunks, esophageal vessels, lymphatics
• Clinical role: Part of anti-reflux mechanism; site of hiatal hernias