Diaphragmatic Hernias
Bochdalek, Morgagni, hiatal (Types I–IV), and traumatic — classification, urgency, and repair principles.
Classification
- Congenital diaphragmatic hernia (CDH)
- Hiatal hernia (acquired)
- Traumatic diaphragmatic hernia
Congenital diaphragmatic hernia (CDH)
Bochdalek hernia — posterolateral (most common CDH)
Failure of closure of the pleuroperitoneal canal — typically on the left side (85%) as the right side closes earlier and is partially protected by the liver. Abdominal viscera herniate into the left chest — small bowel, stomach, colon, and occasionally spleen. The ipsilateral lung is hypoplastic due to compression during development.
Presentation: Neonatal respiratory distress — tachypnoea, cyanosis, absent breath sounds on left, bowel sounds audible in left chest, and scaphoid abdomen. CXR shows bowel loops in the left hemithorax with mediastinal shift to the right.
Immediate management: intubation and nasogastric decompression to reduce bowel distension. Surgical repair is deferred until pulmonary hypertension is stabilised — typically 24–72 hours. Premature repair before stabilisation carries high mortality. ECMO may be required as a bridge to surgery in severe cases.
Repair: Abdominal or thoracoscopic approach. Primary repair preferred using non-absorbable sutures. Synthetic patch (PTFE / Gore-Tex) for large defects where primary closure would be under tension. Survival 70–90% in high-volume centres.
Morgagni hernia — anterior (rare CDH)
Failure of fusion of the sternal and costal components of the diaphragm anteriorly — creates a defect at the foramen of Morgagni, almost always on the right side. Far less common than Bochdalek. Often asymptomatic in adults, discovered incidentally. Contents: omentum and transverse colon. Surgical repair is indicated when diagnosed — laparoscopic repair is now standard.
Hiatal hernia
Widening of the oesophageal hiatus allows herniation of abdominal contents into the posterior mediastinum. The oesophageal hiatus is normally bounded by the right crus and transmits only the oesophagus and vagus nerves.
| Type | Description | Features |
|---|---|---|
| Type I — Sliding (95%) | GOJ slides above the diaphragm into the posterior mediastinum; stomach retains normal orientation | Associated with GORD; treated medically unless refractory; laparoscopic fundoplication if surgical |
| Type II — Rolling / para-oesophageal (true PEH) | GOJ remains below the diaphragm; gastric fundus rolls up alongside oesophagus through the hiatus | Risk of gastric volvulus, strangulation, perforation; elective repair recommended for all fit patients |
| Type III — Mixed | Both GOJ and fundus above the diaphragm | Combines features of Types I and II |
| Type IV | Other abdominal organs herniate in addition to the stomach (omentum, colon, spleen) | Large defect; high risk of complications |
Acute gastric volvulus in a para-oesophageal hernia is a surgical emergency — presents with the Borchardt triad: severe epigastric pain, intractable retching without vomiting, and inability to pass a nasogastric tube. Urgent surgical repair is required. Elective repair should be offered to all fit patients with known PEH before this complication occurs — the risk of acute volvulus is approximately 1–2% per year but carries high mortality when it occurs.
Laparoscopic surgical repair of hiatal hernia consists of: reduction of hernia sac contents into the abdomen → excision of the hernia sac → crural repair (approximation of the right and left crura behind the oesophagus with non-absorbable sutures) → anti-reflux procedure (Nissen 360° fundoplication, or partial wrap for patients with poor oesophageal motility). Mesh reinforcement of the crural repair is used for large defects to reduce recurrence.
Traumatic diaphragmatic hernia
Most commonly caused by blunt trauma (RTA, fall from height). Left-sided in 75–80% — the liver buffers the right hemidiaphragm. Small penetrating injuries may be missed acutely and present months to years later as a chronic diaphragmatic hernia with intestinal obstruction.
Diagnosis: CXR sensitivity for diaphragm rupture is only 40–60% — a normal CXR does not exclude injury. CT is the investigation of choice but still misses up to 30% of injuries. Diagnostic signs on CT: visceral herniation, "collar sign" (constriction of herniated bowel at the defect), "dependent viscera sign" (posteriorly displaced viscera resting against the posterior chest wall). Diagnostic laparoscopy is the gold standard when imaging is inconclusive.
Diaphragmatic injury is rarely isolated — always assume associated injuries to spleen (left-sided), liver (right-sided), and hollow viscera. Haemorrhage control takes priority over diaphragm repair. The diaphragm can be repaired safely after bleeding is controlled — a temporary delay does not worsen outcome.
Repair: Primary repair with non-absorbable interrupted mattress sutures — full-thickness bites essential. Synthetic mesh (PTFE, polyprolene) for large defects. For chronic traumatic hernias, thoracotomy is preferred — adhesions between herniated viscera and pleura require sharp dissection under direct vision.
All clinical content should be verified against current guidelines before clinical application. This resource is intended for revision and educational purposes only.
Standard textbooks
- Shields TW, LoCicero J, Reed CE, Feins RH. General Thoracic Surgery. 7th ed. Lippincott Williams & Wilkins.
- Sellke FW, del Nido PJ, Swanson SJ. Sabiston & Spencer Surgery of the Chest. 9th ed. Elsevier.
- Pearson FG, et al. Thoracic Surgery. 3rd ed. Churchill Livingstone.