What is the appropriate evaluation and management of a diaphragmatic hernia (congenital or acquired)?

Evaluation and Management of Diaphragmatic Hernia

For complicated diaphragmatic hernias, CT scan of the chest and abdomen is the diagnostic gold standard, and laparoscopic repair is the preferred surgical approach in hemodynamically stable patients, while open repair with potential damage control surgery is mandatory for unstable patients. 1, 2

Initial Diagnostic Approach

Imaging Strategy

• CT scan of the chest and abdomen serves as the gold standard for diagnosing complicated diaphragmatic hernias, allowing evaluation of defect size, herniated organs, degree of pulmonary hypoplasia, and associated anomalies 1, 2
• For neonates and patients with respiratory signs, begin with anteroposterior and lateral chest radiograph as the initial study 2
• In acute care settings, diaphragmatic hernia is frequently missed because it is rare, presents with nonspecific signs, and clinicians often do not consider it 2

Mandatory Cardiac Assessment

• Routine echocardiography is required for every congenital diaphragmatic hernia (CDH) patient to assess pulmonary hypertension severity and identify associated congenital heart disease 2
• Pulmonary hypertension coexists with CDH in approximately 63% of patients and raises mortality to approximately 45%, making cardiac assessment prognostically critical 2

Classification and Epidemiology

Congenital Diaphragmatic Hernias

• Bochdalek hernia accounts for approximately 95% of CDH, occurring on the posterior left side in approximately 85% of cases and on the right side in approximately 15% 2
• Adult-onset CDH is rare (incidence 0.17%), typically presenting around 40 years of age with nonspecific gastrointestinal and respiratory complaints 2
• Delayed diagnosis occurs in approximately 5-45% of all congenital diaphragmatic hernias 2

Acquired Diaphragmatic Hernias

• Traumatic diaphragmatic hernias are the most common acquired form, affecting 1-5% of motor vehicle crash victims and 10-15% of penetrating lower chest injuries 2
• Penetrating trauma contributes to approximately 65% of all traumatic diaphragmatic hernias but produces smaller defects than blunt trauma 2
• Overall diaphragmatic rupture occurs in 2.1% of blunt trauma cases and 3.5% of penetrating trauma cases 2

Hiatal Hernias

• Type I (sliding) represents approximately 90% of hiatal hernias, where the esophageal hiatus widens allowing herniation of the gastric cardia 2, 3
• Type II (paraesophageal) accounts for approximately 10%, involving gastric fundus herniation while the gastroesophageal junction remains in normal position 2, 3
• Type III combines features of Types I and II 2, 3
• Type IV is a large hernia containing stomach, colon, and spleen 2, 3

Life-Threatening Complications to Recognize

Complicated diaphragmatic hernia may lead to:

• Organ incarceration, perforation, or strangulation 2
• Respiratory failure from lung compression 2
• Cardiac tamponade from heart compression 2
• Tension gastrothorax causing obstructive shock and cardiac arrest 4

Neonatal CDH Management Protocol

Immediate Respiratory Support

• Immediate endotracheal intubation is mandatory to keep peak inspiratory pressures low and avoid large tidal volumes 2
• High-frequency oscillatory ventilation is reasonable when lung compliance is poor, tidal volumes are low, and gas exchange is inadequate 2

Pulmonary Hypertension Management

• Inhaled nitric oxide may improve oxygenation in severe pulmonary hypertension but use cautiously if left ventricular dysfunction is suspected 2
• Extracorporeal membrane oxygenation (ECMO) is recommended for patients with severe pulmonary hypertension unresponsive to medical therapy 2

Surgical Management Algorithm

Patient Stratification by Hemodynamic Status

For Hemodynamically Stable Patients:

• Laparoscopic repair is the preferred approach because it enables early detection of small diaphragmatic injuries and is associated with fewer postoperative complications 1, 2
• Biological and bio-absorbable meshes are preferred for diaphragmatic reinforcement because they reduce recurrence rates compared with synthetic alternatives 2

For Hemodynamically Unstable Patients:

• Open repair is mandatory and should be performed immediately 1, 2
• Damage control surgery is an option in the management of critical and unstable patients 1
• Open repair is also indicated when exploratory laparotomy is required or when laparoscopic expertise or equipment is unavailable 1, 2

Critical Surgical Pitfall: Viscero-Abdominal Disproportion

When large chronic hernias are present, surgeons must anticipate that primary abdominal closure may not be possible 5:

• Multiple operations may be necessary to correct the defect and achieve closure 5
• Extended bowel resection may be required to reduce the volume of abdominal contents 5
• Laparostomy may be needed to reduce the risk of abdominal compartment syndrome and hernia recurrence 5

Key Diagnostic Pitfalls to Avoid

• Do not postpone diagnosis by attributing neonatal respiratory distress to common conditions such as pneumonia or bronchiolitis 2
• Right-sided CDH is particularly challenging as the liver may create a solid appearance mimicking pleural effusion or consolidation 6
• In isolated persistent pulmonary hypertension of the newborn (PPHN), chest radiography shows lung fields without abdominal viscera in the thorax, which is the key distinguishing feature from CDH 6
• Consider iatrogenic anterior diaphragmatic hernia after cardiac surgery requiring pericardial drainage, maintaining a high index of suspicion 7