In a newborn with congenital diaphragmatic hernia, how should surgical repair be performed, including timing after stabilization, preferred approach, and techniques for closing the diaphragmatic defect?

Surgical Management for Congenital Diaphragmatic Hernia

Surgery for congenital diaphragmatic hernia should be performed after physiological stabilization (not emergently), using an open abdominal approach in most cases, with primary repair using interrupted non-absorbable sutures for small defects and biosynthetic/biological mesh reinforcement for defects larger than 3 cm.

Timing of Surgery

Delayed repair after stabilization is the current standard of care 1, 2. The era of emergent CDH repair is over—this shift from aggressive early intervention to permissive hypercapnea and elective repair has dramatically improved survival from 50% to near 80% 3.

Operate when the infant achieves:

• Mean arterial blood pressure normal for gestational age
• Preductal oxygen saturation 85-95% on FiO2 <50%
• Lactate <3 mmol/L
• Urine output >2 mL/kg/h 4

While most centers delay 24-48 hours or longer, some stable patients may benefit from earlier repair to reduce hospital stay 2. However, prioritize physiological stability over arbitrary timing.

Surgical Approach

For unstable patients or those requiring laparotomy: Use open abdominal approach 1. This remains the gold standard, particularly for large defects 2, 5.

For stable patients with smaller defects: Minimally invasive surgery (thoracoscopy or laparoscopy) can be considered, but only in experienced hands 6, 4. Thoracoscopic repair shows shorter hospital stays (13 vs 19 days), faster ventilator weaning (4 vs 6 days), and earlier feeding (4 vs 7 days) 6. However, MIS has higher recurrence rates and a steep learning curve 2.

Key selection criteria for thoracoscopic approach:

• Weight >2.0 kg
• Liver remains in abdomen
• No intestinal obstruction
• No severe cardiopulmonary anomalies
• Not requiring high-frequency oscillation or ECMO 4

Common pitfall: Attempting MIS in unstable patients or with large defects increases recurrence risk. When in doubt, choose open repair.

Repair Technique

Primary repair with interrupted non-absorbable sutures (2-0 or 1-0) in two layers should always be attempted first 1. This provides a flat surface and prevents mesh extrusion.

For defects >3 cm or when edges cannot be approximated without tension:

• Use mesh reinforcement to avoid the 42% recurrence rate seen with primary repair under tension 1
• Biosynthetic or biological meshes are preferred over synthetic materials due to lower recurrence rates, higher infection resistance, and reduced displacement risk 1
• Mesh should overlap defect edges by 1.5-2.5 cm 1
• Avoid primary closure if the distance between diaphragm edge and chest wall exceeds 3-4 cm 1

For very large defects (>8 cm or >20 cm²), mesh interposition is necessary 1. The diaphragm can be reattached to ribs by encircling them for fixation, even at higher rib levels than anatomical 1.

Mesh fixation: Use transfascial sutures or tackers, but avoid tackers near the pericardium due to cardiac injury risk 1.

Special Considerations for CDH

Fundoplication: The incidence of gastroesophageal reflux after CDH repair reaches 62% 1. Fundoplication should be performed during congenital hernia repair 1. Nissen and Toupet techniques have similar efficacy, though some data suggest lower recurrence with Toupet 1.

Hernial sac excision: This remains controversial 1. Retention causes no obvious complications in most cases, but excision may reduce recurrence when colon or stomach is contained within the sac. Weigh this against risks of pneumomediastinum or mediastinal structure injury.

For unstable patients: Damage Control Surgery is life-saving when the patient has intraoperative instability, hypothermia, coagulopathy, or acidosis 1. Leave the abdomen open if the diaphragm cannot be closed to prevent compartment syndrome.

ECMO Considerations

Surgery on ECMO poses bleeding risks but may offer survival benefits in select cases 2, 5. This decision requires balancing anticoagulation risks against the potential for successful repair in critically ill infants.

Recurrence Prevention

Recurrence is a major concern, especially with large defects and patch repairs 2. Prevention strategies:

• Ensure tension-free repair
• Use appropriate mesh (biological/biosynthetic preferred)
• Adequate mesh overlap (1.5-2.5 cm)
• Avoid absorbable sutures for primary repair 1
• Meticulous surgical technique

For recurrences, open reoperation is standard, with MIS reserved only for select cases 2.