A Bochdalek hernia is the most common type of congenital diaphragmatic hernia (CDH), a defect in the diaphragm present from birth. This structural gap allows abdominal organs, such as the intestines, stomach, or liver, to move into the chest cavity. Accounting for 80% to 95% of all CDH cases, Bochdalek hernias typically occur on the left side (about 85% of cases). The resulting compression of developing lung tissue often leads to life-threatening respiratory problems immediately after birth.
Anatomy and Developmental Origin
The diaphragm forms between the seventh and tenth weeks of gestation through the fusion of four different structures. A Bochdalek hernia arises from the failure of the posterolateral opening, known as the foramen of Bochdalek, to close completely. This failure creates a persistent opening allowing abdominal contents to migrate into the thoracic space.
The herniation mechanically compresses the developing fetal lungs, restricting growth and causing pulmonary hypoplasia. The severity of respiratory distress in the newborn is directly proportional to the degree of lung underdevelopment. Defects occur more frequently on the left side because the right side closes earlier and the liver acts as a protective barrier.
Signs and Identification
Identification can occur before birth via routine medical imaging or immediately after delivery due to severe symptoms. Prenatal diagnosis is often made during a standard fetal ultrasound. The ultrasound may reveal abdominal organs, such as the stomach, within the chest cavity, or a shift of the heart away from the hernia. Excess amniotic fluid, known as polyhydramnios, can also indicate the condition.
Most symptomatic cases are identified in newborns presenting with severe cardiorespiratory distress shortly after delivery. Newborns often exhibit rapid breathing (tachypnea) and a blue discoloration of the skin (cyanosis) due to insufficient oxygen. A physical examination may reveal a scaphoid, or sunken, appearance of the abdomen, as the organs have relocated to the chest. Diagnosis is confirmed postnatally using a chest X-ray, which shows abdominal viscera in the chest cavity and a displaced heart.
Immediate Medical Management
Immediate medical management focuses on stabilizing the infant’s breathing and circulation before surgical repair. Upon diagnosis, the infant is intubated and placed on mechanical ventilation for respiratory support. A specific care strategy is used to avoid excessive pressure and over-expansion of the small, underdeveloped lungs, which could cause further injury.
Stabilization primarily involves addressing persistent pulmonary hypertension (PPHN), a common and severe complication. If standard ventilation is insufficient, specialized life support known as Extracorporeal Membrane Oxygenation (ECMO) may be used. ECMO acts as a temporary heart and lung bypass, oxygenating the blood outside the body to allow the lungs to rest and recover.
Surgical repair is performed once the infant is medically stable, often delayed several days after birth to allow the lungs and pulmonary vasculature to improve. The procedure involves moving the herniated abdominal organs back into the abdominal cavity and closing the defect in the diaphragm. The surgeon may close the hole directly with sutures, or a synthetic patch may be needed if the defect is too large.
Long-Term Health Considerations
Survivors often face chronic health issues requiring specialized long-term follow-up. The most significant concern is the residual effect of pulmonary hypoplasia, which leads to chronic lung disease and the need for supplemental oxygen or ongoing respiratory therapies. Impaired lung function can persist into childhood and adulthood, requiring continuous monitoring by pulmonologists.
Persistent pulmonary hypertension of the newborn (PPHN) can also have lasting effects on the heart and lungs, necessitating continued management to avoid complications. Gastrointestinal issues are also common, with a high prevalence of gastroesophageal reflux disease (GERD) seen in 30% to 80% of survivors. This reflux is related to the abnormal positioning of the stomach and the effects of the diaphragmatic repair.
Children who survive this condition are at risk for developmental and growth delays, highlighting the need for a multidisciplinary approach to care. Teams involving specialists like gastroenterologists, pulmonologists, and developmental pediatricians are necessary to monitor growth, manage feeding difficulties, and address any neurodevelopmental impairments. Recurrence of the hernia is also a possibility, especially with larger defects or those repaired with a patch, requiring ongoing radiological surveillance.