7 Interesting Facts of Congenital Diaphragmatic Hernia
- Congenital diaphragmatic hernia is a diaphragmatic defect, present since birth, that allows herniation of abdominal organs into the thoracic cavity
- Most cases are identified at routine prenatal ultrasonography; postnatal presentation is with respiratory distress beginning acutely after birth
- Uncommonly, condition is asymptomatic in neonatal period and presents later in life with symptoms such as abdominal pain, cough, dyspnea, or symptoms of bowel obstruction
- Diagnosis is established on the basis of clinical and radiologic findings
- In the neonate, pulmonary hypoplasia and pulmonary hypertension resulting from herniation of abdominal viscera into the chest constitute the most significant clinical issue (not the diaphragmatic defect itself)
- Initial management is supportive and is aimed at reducing compression of lungs and providing ventilatory and hemodynamic support
- Surgical repair in neonates is usually undertaken 1 to 2 weeks after birth and involves primary or patch closure of diaphragm via open transabdominal approach
- Surgical repair is also indicated in cases of delayed diagnosis; may be performed by open approach (transthoracic, transabdominal, or thoracoabdominal) or by minimally invasive surgery (via thoracoscopy or laparoscopy)
Pitfalls
- Be aware of possible late presentation in adults with nonspecific gastrointestinal signs and symptoms or (rarely) strangulated herniated viscera
- Congenital diaphragmatic hernia is a diaphragmatic defect, present since birth, that allows herniation of abdominal organs into the thoracic cavity
Classification
- Classification by location
- Posterolateral hernia (Bochdalek hernia)
- Often accompanied by herniation of stomach, intestines, liver, and/or spleen into thoracic cavity
- Constitutes 80% to 90% of all congenital diaphragmatic hernias
- About 85% of Bochdalek hernias are left-sided, about 10% are right-sided, and about 5% are bilateral
- Anterior retrosternal or parasternal hernia (Morgagni hernia)
- Allows herniation of liver or intestines into thoracic cavity
- Constitutes 2% of all congenital diaphragmatic hernias
- Often asymptomatic during newborn period, presenting later (with pain, cough, and dyspnea)
- Posterolateral hernia (Bochdalek hernia)
- Classification by size, according to the Congenital Diaphragmatic Hernia Study Group
- A: diaphragmatic defects are entirely surrounded by muscle
- B: less than 50% of chest wall devoid of diaphragm tissue
- C: more than 50% of chest wall devoid of diaphragm tissue
- D: complete or near complete absence of diaphragm
- Classification by phenotype
- Isolated
- 50% to 60% of congenital hernias are isolated and no other abnormalities are present
- Complex (syndromic)
- 30% to 40% of cases are associated with other abnormalities, either as part of a known syndrome or (more often) in a sporadic combination
- In many of the cases with a known syndrome and in some of the cases without, a chromosomal abnormality is present
- Isolated
Clinical Presentation
History
- Most cases are identified prenatally at routine prenatal ultrasonography
- Typically postnatal presentation is respiratory distress beginning acutely after birth
- Degree of respiratory compromise depends on severity of lung compression and pulmonary hypoplasia and on development of pulmonary hypertension
- 5% to 10% of patients are asymptomatic in neonatal period and may present later in life with the following symptoms:
- Abdominal pain or discomfort
- Respiratory symptoms, including cough, chest pain, and dyspnea or even respiratory distress
- Obstructive symptoms, including dyspepsia, nausea, vomiting, bloating, constipation, obstipation, postprandial fullness, dysphagia, and retching
- Rarely, patient can present with serious complications of strangulated herniated viscera
Physical examination
- Findings include:
- Scaphoid abdomen
- Barrel chest
- Absent breath sounds
- Displaced heartbeat owing to mediastinal shift
- May be associated with other congenital anomalies
Causes
- Common congenital defect; believed to be due to incomplete fusion of pleuroperitoneal folds during early fetal development
- Mechanism and exact time of occurrence during development have not been conclusively determined
- Resulting defect in diaphragm and herniation of abdominal organs into thoracic cavity interfere with fetal lung development, leading to pulmonary hypoplasia and pulmonary hypertension
- Occurs in approximately 1 in 3500 live births (ranging from 1 in 300 to 1 in 5000); the prevalence in stillborn fetuses and neonatal deaths is unknown
Risk factors and/or associations
Age
- Majority of congenital diaphragmatic hernias are diagnosed prenatally or shortly after birth
- 5% of cases are diagnosed in childhood or adulthood
Sex
- Males have a slightly higher risk for developing congenital diaphragmatic hernias (62% of patients are male)
Genetics
- Most cases are sporadic, but there is increasing evidence of genetic causes among these cases
- Some familial clusters suggest autosomal recessive, autosomal dominant, or X-linked inheritance
- 10% of all patients have a chromosomal abnormality, most often trisomy 13, 18, or 21 or tetrasomy 12p
- Other chromosomal abnormalities found in association with congenital diaphragmatic hernia include:
- Diaphragmatic hernia, congenital (OMIM %142340)
- Diaphragmatic hernia 2 (OMIM %222400)
- Diaphragmatic hernia 3 (OMIM #610187)
- Other chromosomal abnormalities found in association with congenital diaphragmatic hernia include:
- 10% of patients have an underlying syndrome, such as:
- Fryns syndrome (OMIM %229850)
- More than 80% of patients have diaphragmatic hernia
- Donnai-Barrow syndrome (OMIM #222448)
- 70% of patients have diaphragmatic hernia
- Matthew-Wood syndrome (OMIM #601186)
- 50% of patients have diaphragmatic hernia
- Cornelia de Lange syndrome (5 OMIM entities)
- Up to 5% of patients have diaphragmatic hernia
- Fryns syndrome (OMIM %229850)
Other risk factors/associations
- Advanced paternal age (but not maternal age) has been associated with an increased risk for congenital diaphragmatic hernia
Diagnostic Procedures
Primary diagnostic tools
- Often diagnosed prenatally by visualization of abdominal organs within the thoracic cavity or through other suspicious findings (eg, mediastinal shift, abnormal heart position) on routine prenatal ultrasonography
- Fetal MRI provides additional information about degree of lung hypoplasia and liver herniation in moderate to severe cases
- Suspect diagnosis postnatally on the basis of respiratory distress and absence of breath sounds in the neonate; confirm by chest and abdominal radiography
- Additional evaluation includes fetal/neonatal echocardiography to identify associated cardiac abnormalities and assess for pulmonary hypertension and shunting
- In adults with a previously missed diagnosis, signs and symptoms are nonspecific and diagnosis may be based on findings from chest and abdominal radiography, CT, or MRI, as well as from upper gastrointestinal tract barium series
Imaging
- Fetal ultrasonography
- Most congenital cases are detected on routine prenatal ultrasonography
- Definitive diagnosis is based on presence of abdominal organs within thorax
- Other suggestive findings include:
- Pleural effusion
- Mediastinal shift
- Abnormal position of heart
- Absence of stomach below diaphragm
- Small abdominal circumference
- Polyhydramnios
- Additional evaluation includes fetal/neonatal echocardiography to identify associated cardiac abnormalities and assess for pulmonary hypertension and shunting
- Fetal MRI
- Assesses lung volume and extent of liver herniation, which have prognostic value
- Best method to detect discontinuities of diaphragmatic tissue and to estimate size of defect
- Chest and abdominal radiography
- Findings may include:
- Minimal or no aerated lung on affected side
- Mediastinal shift suggesting a unilateral large hernia
- Soft tissue opacity with or without an air-fluid level within chest
- Bowel loops running in unusual vertical patterns
- Displacement or upward deformity of transverse colon
- Absent intra-abdominal bowel loops
- Negative radiographic findings do not exclude diaphragmatic hernia because herniation of abdominal contents may be intermittent
- Findings may include:
- Chest and abdominal CT scan
- May show diaphragmatic defect and show abdominal viscera in thorax
Differential Diagnosis
Most common
- Bronchogenic cysts
- Rare bronchopulmonary foregut malformation, filled with fluids or soft tissue
- Most are asymptomatic and discovered only incidentally; large cysts may cause respiratory distress and chest pain
- Similar clinical signs and symptoms include chest pain, cough, dyspnea, and respiratory distress
- Obstructive symptoms (eg, nausea, vomiting, dysphagia, abdominal pain) are typically absent
- Appearance on radiography and MRI may be similar to that of diaphragmatic hernia
- Exploratory surgery identifies an existing cyst or herniation
- Congenital pulmonary airway malformation (congenital cystic adenomatoid malformation)
- Abnormal cell proliferation in lung and decreased cell death; often an entire lobe is replaced by abnormal tissue
- Most cysts are asymptomatic; very large cysts can cause respiratory distress, mediastinal shifts, and heart compression
- Similar clinical signs and symptoms include chest pain, cough, dyspnea, and respiratory distress
- Obstructive symptoms (eg, nausea, vomiting, dysphagia, abdominal pain) are typically absent
- Appearance on radiography and MRI may be similar to that of diaphragmatic hernia
- Exploratory surgery identifies an existing cyst or herniation
- Cystic teratomas
- Benign tumors consisting of differentiated tissue arising from endoderm, ectoderm, and/or mesoderm
- Small tumors are asymptomatic; larger tumors may displace the heart and occupy lung space, leading to respiratory distress and abdominal pain
- Prenatal ultrasonography and MRI can detect cystic teratomas but may not allow distinction from diaphragmatic hernia
- Exploratory surgery identifies an existing cystic tumor or herniation
What's on this Page
Treatment Goals
- Reduce hernia and repair diaphragmatic defect
- Prevent or reverse pulmonary complications
Disposition
Admission criteria
Adult patients with congenital diaphragmatic hernia who present with respiratory distress or acute abdomen should be hospitalized
Criteria for ICU admission
- Patients with congenital diaphragmatic hernia that is diagnosed before or at birth are managed in the neonatal ICU until recovery after surgery
Recommendations for specialist referral
- Refer patients with prenatally diagnosed fetuses for fetal echocardiography, genetic counseling, close obstetric monitoring, and, possibly, fetal intervention
- Arrange for delivery at a tertiary care center with immediate access to neonatology center, pediatric surgeons, and extracorporeal membrane oxygenation
- Postnatal management involves a multidisciplinary team including pediatric surgeon, developmental pediatrician, nutritionist, and pulmonologist to address respiratory, neurologic, gastrointestinal, and nutritional difficulties
- Referral to an otologist is required to monitor hearing development because 25% of patients with congenital diaphragmatic hernia develop sensorineural hearing loss
- Adult patients with congenital diaphragmatic hernia are typically managed by surgeon
Treatment Options
Prenatal management
- Primarily consists of close obstetric monitoring and careful planning for delivery
- Antenatal corticosteroids may be administered for standard indications to reduce morbidity and mortality associated with preterm delivery
- Routine administration of pre- or postnatal corticosteroids is not recommended
- Fetal endoscopic tracheal occlusion is an emerging technique to prevent or reverse pulmonary hypoplasia
- Procedure typically is performed between 27 and 30 weeks of gestation
- Balloon is endoscopically placed in fetal trachea; when inflated, balloon prevents fluid egress from lung, causing an increase in transpulmonary pressure and stimulating lung growth
- Initial results appear promising and further studies are underway
Postnatal management
- Pulmonary hypoplasia and pulmonary hypertension that result from herniation of abdominal viscera into the chest constitute the most significant clinical issue (not the diaphragmatic defect itself)
- Initial supportive care
- Immediate intubation and artificial ventilation after birth
- Nasogastric tube insertion
- Umbilical arterial and venous catheter placement
- Hemodynamic support with fluids and inotropic agents as necessary
- Inhaled nitric oxide
- Commonly given to improve oxygenation and reduce the need for extracorporeal membrane oxygenation; however, it does not appear to improve outcomes
- Vasodilators such as sildenafil, milrinone, prostacyclin, and bosentan
- Sometimes used to treat severe pulmonary hypertension, but there is minimal evidence to support their use in patients with congenital diaphragmatic hernia
- Extracorporeal membrane oxygenation (if conventional supportive measures have failed)
- However, there is no evidence that this treatment is associated with improved outcomes
- Surgical treatment
- Optimal timing for surgical repair of congenital hernias is unclear, and timing of surgery does not appear to influence outcomes; early intervention (within 8 days after birth) does not increase survival rate
- Typically undertaken 1 to 2 weeks after birth to allow infant’s condition to stabilize and pulmonary vascular reactivity to decrease or resolve
- Criteria indicating readiness for surgical repair may include:
- No shunting episodes
- Ventilator setting with fraction of inspired oxygen less than 50%
- Normal acid-base balance
- Urine output more than 1 mL/kg/hour
- Estimated pulmonary arterial pressure less than systemic pressure
- No anasarca
- Normal mean arterial pressure for age
- Preductal oxygen saturation of 85% to 95%
- Off, or ready to come off, extracorporeal membrane oxygenation
- Surgical approach for diaphragmatic repair is selected according to operating surgeon’s preference and experience
- Typically involves primary or patch closure of diaphragm through an open transabdominal approach
- Large defects that cannot be closed by primary repair may be patched with artificial patches (polytetrafluoroethylene, biosynthetic, or composite) or with autologous muscle flaps; oversized, tension-free polytetrafluoroethylene or Gore-Tex patches are preferred owing to reduced rate of recurrence
- Thoracoscopic approach is not recommended in neonates owing to morbidity from hypercapnia and acidosis and to increased incidence of hernial recurrence
- Typically involves primary or patch closure of diaphragm through an open transabdominal approach
Management of late-presenting congenital diaphragmatic hernia in adult patients involves surgical reduction and repair
Nondrug and supportive care
Adults with respiratory distress require intubation and artificial ventilation
Neonates require immediate intubation after birth, followed quickly by artificial ventilation and nasogastric tube placement
- Gentle ventilation with permissive hypercapnia is preferred method
- High-frequency oscillatory ventilation may also be used
Procedures
Diaphragmatic repair and hernia reduction
General explanation
- Herniated viscera are reduced back into abdominal cavity and diaphragmatic defect is closed
- In neonates, transabdominal approach is preferred
- In adults, may be performed by an open approach (transthoracic, transabdominal, or thoracoabdominal) or by minimally invasive surgery (via thoracoscopy or laparoscopy)
- Small defects can be sealed with sutures alone
- Large defects that cannot be closed by primary repair may be patched with artificial patches (polytetrafluoroethylene, biosynthetic, or composite) or with autologous muscle flaps; oversized, tension-free polytetrafluoroethylene or Gore-Tex patches are preferred owing to reduced rate of recurrence
Indication
- Diaphragm defect or injury with or without herniation of abdominal viscera
Complications
- Gastrointestinal perforation
- Hemorrhage
- Chylothorax
- Pneumothorax
- Patch infection
- Gastroesophageal reflux
Comorbidities
- Sensorineural hearing loss (25% of patients)
- Cardiac abnormalities
- Prematurity
Monitoring
- Long-term monitoring is required after congenital diaphragmatic hernia repair for early identification and timely management of associated hearing loss and cardiopulmonary, gastrointestinal, nutritional, neurodevelopmental, and musculoskeletal conditions
Complications
- Pulmonary hypoplasia
- Feeding difficulties
- Failure to thrive
- Persistent pulmonary hypertension
- Chronic lung disease
- Cardiac displacement
- Gastric volvulus and strangulation
- Bowel obstruction
- Reherniation after repair
- Hypotonia and motor disabilities
- Musculoskeletal abnormalities (eg, chest asymmetry, pectus excavatum, scoliosis)
Prognosis
- Without treatment, mortality rate is 100%
- Approximately 31% of patients diagnosed prenatally with congenital diaphragmatic hernia die within the first 24 hours after birth
- Mortality is lower in patients with isolated congenital diaphragmatic hernia than in patients with additional malformations and syndromes
- Survival is influenced by size and location of defect
- Studies suggest that right-sided hernias are associated with greater mortality than left-sided hernias
- Bilateral hernias are always associated with high mortality
- Prolonged need for gastric tube feeding and need for extracorporeal membrane oxygenation correlate with worse condition and worse outcome
- Almost all patients with congenital diaphragmatic hernia have pulmonary hypoplasia that resolves within 2 years of life in those who survive
- Most children will later have no symptoms at rest but will have a higher risk for respiratory decompensation with illness or exercise
- Cognitive, language, and motor domain scores are significantly below average at age 2 years in affected children
- Survival rate of patients presenting later than 30 days after delivery is 100%
Screening
At-risk populations
- All fetuses are routinely screened for malformations, including diaphragmatic herniation
Screening tests
- Routine prenatal ultrasonography
References
Pober BR et al: Congenital diaphragmatic hernia overview. In: Adam MP et al, eds: GeneReviews [internet]. Seattle, WA: University of Washington; 1993-2018