What is the appropriate diagnostic workup and treatment approach for congenital and acquired diaphragmatic hernia in neonates, children, and adults, including criteria for surgical repair versus conservative management?

Diaphragmatic Hernia: Diagnostic Workup and Treatment Approach

All complicated diaphragmatic hernias require surgical repair, with laparoscopic approach preferred for hemodynamically stable patients and open repair reserved for unstable patients or those requiring damage control surgery. 1

Classification and Epidemiology

Diaphragmatic hernias are classified into two main categories 1:

Congenital Diaphragmatic Hernia (CDH)

• Bochdalek hernia accounts for 95% of CDH cases, occurring posterolaterally with 85% on the left side and 15% on the right 1
• Occurs in 1 in 2000-3000 newborns 2
• In adults, CDH has an incidence of 0.17% and presents at an average age of 40 years 1
• Results from incomplete diaphragm development during the eighth week of gestation 1

Acquired Diaphragmatic Hernia (ADH)

• Traumatic hernias are most common, occurring in 1-5% of vehicle crash victims and 10-15% of penetrating lower chest injuries 1
• Penetrating trauma accounts for 65% of traumatic cases but creates smaller defects than blunt trauma 1
• Overall diaphragmatic rupture occurs in 2.1% of blunt trauma and 3.5% of penetrating trauma 1

Diagnostic Workup

Gold Standard Imaging

CT scan of the chest and abdomen is the diagnostic gold standard for evaluating complicated diaphragmatic hernia. 1 This imaging modality allows assessment of:

• Defect size and location 3
• Herniated organs and their position 3
• Degree of pulmonary hypoplasia 3
• Associated anomalies 3

Essential Cardiac Evaluation

Echocardiography is mandatory in all cases to evaluate pulmonary hypertension severity and associated congenital heart disease, which directly determines survival. 3 This is particularly critical because:

• Pulmonary hypertension coexists with CDH in 63% of cases 3
• Mortality reaches 45% when pulmonary hypertension is present 3

Clinical Presentation Pitfalls

The diagnosis is frequently missed in acute settings due to 1:

• Rarity of the condition
• Nonspecific clinical findings
• Low clinical suspicion

Right-sided CDH is particularly challenging as the liver may mimic pleural effusion or consolidation on imaging. 3

Treatment Approach: Surgical Indications

Universal Surgical Recommendation

Surgical repair is advised for all adult CDH patients to avoid entrapment and strangulation of abdominal viscera, regardless of symptoms. 4 Even asymptomatic cases discovered incidentally require repair 5.

Neonatal CDH Management

Immediate intubation is required in pediatric patients with CDH to minimize peak inspiratory pressure and avoid large tidal volumes. 6

Ventilation Strategy

• Minimize peak inspiratory pressure and avoid large tidal volumes (Class I; Level of Evidence B) 6
• High-frequency oscillatory ventilation is a reasonable alternative when there is poor lung compliance, low volumes, and deficient gas exchange (Class IIa; Level of Evidence A) 6

Adjuvant Therapies

• Inhaled nitric oxide (iNO) may be used to improve oxygenation in infants with severe pulmonary hypertension, but use with caution in suspected left ventricular dysfunction (Class IIa; Level of Evidence B) 6
• ECMO is recommended for patients with severe pulmonary hypertension who do not respond to medical therapy (Class I; Level of Evidence B) 6

Surgical Technique Selection

Hemodynamically Stable Patients

Laparoscopic repair is the best treatment option for stable patients with complicated diaphragmatic hernias. 1 Benefits include:

• Early diagnosis of small diaphragmatic injuries from thoraco-abdominal trauma 1
• Reduced postoperative complications 1
• Excellent long-term results with low recurrence rates 4

Hemodynamically Unstable Patients

Open repair is considered necessary in the majority of unstable patients. 1 Indications for open approach include:

• Hemodynamic instability 1
• Need for exploratory laparotomy 1
• Lack of laparoscopic skills or equipment 1
• Damage control surgery requirements in critical patients 1

Mesh Reinforcement

Biological and bioabsorbable meshes are preferred for complicated DH repair as they reduce recurrence rates. 1 Suture repair with mesh reinforcement is the preferred technique 4.

Life-Threatening Complications

Complicated DH can present with 1:

• Incarceration, perforation, or strangulation of herniated organs
• Respiratory failure from lung compression
• Cardiac tamponade from heart compression
• Tension gastrothorax (particularly in late-presenting pediatric cases) 7

Common Pitfall: Late-presenting CDH with tension gastrothorax can be misdiagnosed as tension pneumothorax on chest x-ray. Always place a nasogastric tube before chest tube placement if excessive vomiting is present, and obtain barium studies if intrathoracic stomach is suspected. 7