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Anatomy Review6 min read

Diaphragm Anatomy and Hiatal Hernia Repair: A Surgical Tech's Review

A focused anatomy review of the diaphragm and esophageal hiatus relevant to hiatal hernia repair and antireflux surgery.

January 16, 2026

The Diaphragm as More Than a Breathing Muscle

The diaphragm is best known as the primary muscle of respiration, but from a surgical anatomy standpoint, it is equally important as the dome-shaped structure separating the thoracic and abdominal cavities, penetrated by several critical openings that allow structures to pass between the two compartments. The esophageal hiatus, the opening through which the esophagus passes to join the stomach, is the anatomical focus of hiatal hernia repair.

The Esophageal Hiatus and Diaphragmatic Crura

The esophageal hiatus is formed primarily by the right and left diaphragmatic crura, muscular bands that arise from the anterior surface of the lumbar vertebrae and curve around to form a sling-like opening. When these crura weaken or the opening enlarges, part of the stomach can migrate upward into the thoracic cavity, producing a hiatal hernia, and surgical repair fundamentally involves narrowing this opening back down by suturing the crura together, a step called crural repair or cruroplasty.

Types of Hiatal Hernias

A sliding hiatal hernia, the most common type, occurs when the gastroesophageal junction itself slides upward through the hiatus into the chest. A paraesophageal hernia is different and generally considered more surgically significant, since the gastroesophageal junction stays in its normal position while a portion of the stomach herniates alongside the esophagus, which carries a risk of the herniated stomach becoming twisted or strangulated, a surgical emergency.

The Fundoplication Component

Hiatal hernia repair is frequently paired with a fundoplication, most commonly a Nissen fundoplication, in which the gastric fundus is wrapped around the distal esophagus and sutured in place to reinforce the lower esophageal sphincter and prevent reflux. Understanding that these are typically two related but distinct steps, first narrowing the hiatal opening, then reinforcing the sphincter mechanism with the fundoplication wrap, helps a surgical tech anticipate the instrument and suture sequence throughout the case.

Vagus Nerve Preservation

The anterior and posterior vagus nerve trunks run directly along the esophagus through the hiatus, and careful dissection to preserve these nerves is a defining technical challenge of this surgery, since injury can cause significant postoperative gastric motility problems. This proximity is why these procedures, whether performed open or laparoscopically, require meticulous, slow dissection in this specific anatomical region.

  • The diaphragmatic crura form the esophageal hiatus and are surgically narrowed during repair
  • Sliding hernias involve upward migration of the gastroesophageal junction itself
  • Paraesophageal hernias carry strangulation risk and are considered more surgically urgent
  • Fundoplication reinforces the lower esophageal sphincter after hiatal repair
  • The vagus nerve trunks require careful preservation throughout the dissection

Recognizing Recurrence Risk

Even with careful crural repair and fundoplication, hiatal hernias can recur over time, particularly in patients with significant obesity, chronic coughing, or other conditions that create persistent increased intra-abdominal pressure against the surgical repair. Understanding that recurrence risk exists helps explain why some surgeons use mesh reinforcement of the crural repair in higher-risk patients, a decision that involves weighing the benefit of reduced recurrence against a small but recognized risk of mesh-related complications specific to this anatomical location.

The surgical technologist supporting these cases should be aware that mesh use is not universal across all hiatal hernia repairs and should confirm with the surgeon during preoperative discussion whether mesh reinforcement is planned for a specific patient, since this affects both instrument and supply preparation for the case.

Recognizing Recurrence Risk

Even with careful crural repair and fundoplication, hiatal hernias can recur over time, particularly in patients with significant obesity, chronic coughing, or other conditions that create persistent increased intra-abdominal pressure against the surgical repair. Understanding that recurrence risk exists helps explain why some surgeons use mesh reinforcement of the crural repair in higher-risk patients, a decision that involves weighing the benefit of reduced recurrence against a small but recognized risk of mesh-related complications specific to this anatomical location.

The surgical technologist supporting these cases should be aware that mesh use is not universal across all hiatal hernia repairs and should confirm with the surgeon during preoperative discussion whether mesh reinforcement is planned for a specific patient, since this affects both instrument and supply preparation for the case.

Patients presenting for revision surgery after a prior hiatal hernia repair has recurred often involve additional technical complexity due to scar tissue from the original operation, and the surgical technologist should anticipate a potentially longer, more dissection-intensive case in this specific clinical scenario compared to a straightforward primary repair.

Anatomy That Connects Multiple Surgical Specialties

The diaphragm and hiatal region sits at a genuine crossroads between general surgery, thoracic surgery, and gastroenterology, and understanding this anatomy thoroughly provides a foundation useful across several related surgical specialties a technologist might encounter throughout a varied career.

This cross-specialty relevance reflects a broader pattern worth recognizing throughout anatomy study generally, where mastering a single well-understood anatomical region often provides transferable value across procedures that might initially seem unrelated on the surface.

Review gastrointestinal anatomy further in our related content, and explore laparoscopic instrumentation in our laparoscopic instruments guide. Strengthen your anatomy foundation with our full CST exam prep program.

This content is for educational purposes only. SurgicalTechPrep is independently developed and is not affiliated with, endorsed by, or sponsored by NBSTSA, AST, or any official certification body. All clinical information should be verified with current standards of practice.

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