Congenital diaphragmatic hernia (CDH) is herniation of abdominal organs (bowel, stomach, spleen, liver) into the thorax through a congenital defect in the diaphragm. Bochdalek type (posterolateral defect, 70-75% left side, 20-25% right side) is most common. Morgagni type (anterior, retrosternal) is rarer (2-5%). CDH is a serious neonatal emergency — abdominal organs in the thorax impede lung development causing pulmonary hypoplasia and pulmonary hypertension. CXR shows bowel loops in the thorax, absent or hypoplastic ipsilateral lung, contralateral mediastinal shift, and loss of diaphragmatic contour. Prenatal US (from 20 weeks) may show stomach or bowel in the thorax. Mortality is 30-40% (depending on degree of pulmonary hypoplasia and pulmonary hypertension). Treatment is stabilization (ECMO may be required) followed by surgical diaphragmatic repair.
Age Range
0-0.1
Peak Age
-
Gender
Male predominant
Prevalence
Uncommon
CDH pathophysiology involves two fundamental mechanisms: (1) Anatomical defect — in Bochdalek type, failure of pleuropericardial membrane closure leads to a posterolateral diaphragmatic defect. Abdominal organs herniate into the thorax through this defect driven by positive intra-abdominal pressure. (2) Pulmonary developmental impairment — abdominal organs in the thorax mechanically impede ipsilateral lung development causing pulmonary hypoplasia; this results not only from mechanical compression but also from disrupted intrauterine lung fluid dynamics and inadequate vascular bed development. The hypoplastic lung has an insufficient pulmonary vascular bed — vascular smooth muscle hypertrophy and abnormal vascular reactivity lead to pulmonary hypertension. CXR findings directly reflect this pathophysiology: bowel loops in thorax — hernia content; absent ipsilateral lung — pulmonary hypoplasia; mediastinal shift — mass effect of herniated organs; diaphragmatic contour loss — diaphragmatic defect. The most important prognostic determinant is degree of pulmonary hypoplasia — lung-to-head ratio (LHR) is used in prenatal assessment.
The signature finding of CDH is bowel loops in the thorax on CXR with loss of ipsilateral diaphragmatic contour. The combination of these two findings confirms CDH diagnosis. On CXR taken immediately after birth, if bowel loops are not yet gas-filled, homogeneous opacity and diaphragmatic loss are seen — typical multiple bubble appearance emerges as bowel gains gas within hours. When NGT is placed, tube tip in the thorax (stomach in thorax) supports diagnosis. In right-sided liver herniation, the bubble appearance may be absent — homogeneous opacity and mediastinal shift are seen. Differential from congenital cystic lung malformations (CPAM, sequestration) is needed.
The most characteristic CXR finding is bowel loops in the left hemithorax (Bochdalek type, 75% left). Gas-filled bowel loops appear as multiple radiolucent (black) round structures in the thorax — this 'bubble' appearance must be distinguished from lung aeration. The left diaphragmatic contour is lost or appears irregular. If the stomach has herniated into the thorax, the nasogastric tube tip is seen in the thorax (if placed). In right-sided hernia, the liver appears as a homogeneous soft tissue opacity in the thorax — may not show the prominent 'bubble' appearance like bowel loops. On CXR immediately after birth, bowel loops may not yet be gas-filled — a homogeneous opacity is seen in the thorax, and the typical appearance emerges as bowel gains gas within hours.
Report Sentence
Gas-filled bowel loops are seen in the left/right hemithorax with loss of ipsilateral diaphragmatic contour; findings are consistent with congenital diaphragmatic hernia (Bochdalek type).
Mass effect of herniated organs pushes mediastinal structures (heart, great vessels, trachea) to the contralateral side. In left CDH, mediastinal shift is to the right — heart is displaced toward the right hemithorax (dextroposition). In right CDH, shift is to the left. The contralateral lung is also partially compressed by pressure effect with decreased aeration. Significant mediastinal shift can cause hemodynamic instability — compression of great vessels reduces cardiac output. CXR shows tracheal and cardiac deviation to the contralateral side.
Report Sentence
Mediastinal structures are displaced to the contralateral side with compression of the contralateral lung; mass effect of herniated organs is prominent.
CDH can be recognized on prenatal US (typically at 18-24 week anomaly scan). In left CDH, the most common finding is the stomach seen in the thorax as a cystic structure — stomach appears as fluid-filled anechoic structure in thorax. Bowel loops may also be seen in thorax. Heart is displaced contralaterally. Pulmonary hypoplasia assessment: lung-to-head ratio (LHR) — contralateral lung area / head circumference ratio is a prognostic determinant (LHR <1.0 poor prognosis). Liver herniation (liver up) is a poor prognostic factor. Polyhydramnios (80%) results from bowel obstruction.
Report Sentence
On prenatal US, cystic structure (stomach) and/or bowel loops are seen in the left/right hemithorax with ipsilateral lung hypoplasia; findings are consistent with congenital diaphragmatic hernia.
Fetal MRI is used complementary to prenatal US for accurate lung volume assessment, determination of hernia contents (bowel vs liver), and assessment of degree of liver herniation. On T2-weighted sequences, lung parenchyma is high signal (fetal lung fluid is T2 hyperintense) — lung volume is calculated with multiplanar measurements. Bowel loops show variable signal on T2. Liver has intermediate signal on T2 and is easily identified in thorax. Fetal MRI provides more accurate total fetal lung volume (TFLV) calculation than LHR — critical for prognosis determination and surgical planning (FETO — fetal endoscopic tracheal occlusion) decisions.
Report Sentence
On fetal MRI, hernia contents (bowel/liver) are seen in the left/right hemithorax with decreased ipsilateral lung volume; TFLV is calculated as ___ mL.
CT may be performed postnatally for surgical planning and complication assessment (rarely indicated in neonates, more often in stable patients). Contrast-enhanced CT evaluates detailed anatomy of hernia contents (bowel, stomach, spleen, liver, kidney), diaphragmatic defect size, pulmonary vascular development, and associated anomalies. Pulmonary artery diameter and branching pattern indicate the degree of pulmonary hypoplasia. CT angiography shows pulmonary vascular bed in detail. Postoperatively, CT may be used for recurrent herniation, residual defect, and lung development follow-up.
Report Sentence
CT shows abdominal organs (bowel/liver/spleen) herniated into the thorax through a left/right diaphragmatic defect with ipsilateral lung hypoplasia.
Criteria
Posterolateral diaphragmatic defect. 90-95% of all CDH cases. 75% left, 20-25% right, 2% bilateral. Perinatal presentation (respiratory distress at birth).
Distinct Features
Left side: stomach, spleen, bowel, and sometimes left liver lobe herniate. Right side: liver and bowel herniate — liver may have protective effect (partially covering defect). Pulmonary hypoplasia and hypertension are main mortality determinants.
Criteria
Anterior, retrosternal diaphragmatic defect (space of Larrey). 2-5% of all CDH cases. Mostly right side (90%). Generally later diagnosis (infancy/childhood or even adulthood).
Distinct Features
Less severe pulmonary effect — usually no pulmonary hypoplasia. Hernia content mostly omentum and transverse colon. CXR shows opacity in anterior mediastinum — cardiophrenic region. Elective surgical repair.
Criteria
Defects in both diaphragms. <2% of all CDH cases. Generally incompatible with life — bilateral pulmonary hypoplasia.
Distinct Features
Highest mortality. ECMO support usually required. Ventilation very difficult due to bilateral pulmonary hypoplasia. High rate of associated anomalies.
Distinguishing Feature
CPAM is an intrapulmonary cystic lesion — diaphragm is intact. In CDH, there is a diaphragmatic defect and abdominal organs are in thorax. CT evaluates diaphragmatic integrity and differentiates hernia content (bowel vs lung cyst).
Distinguishing Feature
In CLE, hyperinflated lung lobe is seen — diaphragm intact, no abdominal organs. CDH's multiple bubble appearance of bowel loops is distinguished from CLE's uniform hyperinflation.
Distinguishing Feature
Sequestration is lung tissue without normal bronchial connection — has systemic arterial supply. In CDH, abdominal organs are in thorax. CT angiography shows sequestration arterial supply, CDH shows bowel and diaphragmatic defect.
Urgency
emergentManagement
surgicalBiopsy
Not NeededFollow-up
specialist-referralCDH is a serious neonatal emergency. Presents at birth with respiratory distress, cyanosis, and scaphoid abdomen (abdominal organs in thorax, abdomen appears concave). Initial management: endotracheal intubation (mask ventilation contraindicated — inflates stomach/bowel increasing lung compression), nasogastric decompression, surfactant, inhaled nitric oxide (pulmonary hypertension treatment), ECMO (if needed). Surgical repair is performed AFTER HEMODYNAMIC STABILIZATION — emergency surgery is no longer recommended. Surgery: primary diaphragmatic repair or prosthetic patch (Gore-Tex). Mortality 30-40%. Good prognostic factors: LHR >1.4, no liver herniation, late prenatal diagnosis, mild pulmonary hypertension. Long-term issues: bronchopulmonary dysplasia, gastroesophageal reflux, nutritional insufficiency, sensorineural hearing loss, neurodevelopmental impairment.
A serious neonatal emergency. Pulmonary hypoplasia and persistent pulmonary hypertension are the primary determinants of mortality and morbidity. Prenatal diagnosis is critical for fetal intervention and delivery planning (ECMO readiness). LHR and o/e TLV are used for prognosis estimation. FETO (fetoscopic tracheal occlusion) is an experimental treatment option in severe cases. Postnatal stabilization (ECMO, gentle ventilation) is essential before surgery. Long-term complications: chronic lung disease, GERD, neurodevelopmental delay.