History• In 1946, Gross reported the first successful repair of aneonatal diaphragmatic hernia in the first 24 hours of life.• for the next decade addressed congenital diaphragmatichernia as a surgical problem and discussed various technicalaspects of surgical repair, including techniques required toclose large defects• In the 1960s, however, Areechon and Reid observed that thehigh mortality rate of congenital diaphragmatic hernia wasrelated to the degree ofpulmonary hypoplasia at birth.[
• Over the past 20 years, pulmonary hypertension andpulmonary hypoplasia have been recognized as the 2cornerstones of the pathophysiology of congenitaldiaphragmatic hernia.• recent years, evidence suggests that cardiac maldevelopmentmay further complicate the pathophysiology of congenitaldiaphragmatic hernia.
Pathophysiology3 basic types of congenital diaphragmatic hernia– posterolateral Bochdalek hernia (occurring at approximately 6 weeksgestation)– anterior Morgagni hernia– hiatus hernia• right-sided hernias (13% of cases), only the liver and aportion of the large bowel tend to herniate.• Left-sided hernias allow herniation of both the small andlarge bowel and intraabdominal solid organs into the thoraciccavity• Bilateral hernias are uncommon and are usually fatal
• Congenital diaphragmatic hernia is characterized by a variabledegree of pulmonary hypoplasia associated with a decrease incross-sectional area of the pulmonary vasculature andalterations of the surfactant system• lungs have a small alveolar capillary membrane for gasexchange, which may be further decreased by surfactantdysfunction• parenchymal disease, increased muscularization of theintraacinar pulmonary arteries appears to occur.• very severe cases, left ventricular hypoplasia is observed.• Pulmonary capillary blood flow is decreased because of thesmall cross-sectional area of the pulmonary vascular bed• flow may be further decreased by abnormal pulmonaryvasoconstriction.
Epidemiology• occurs in 1 of every 2000-3000 live births and accounts for 8%of all major congenital anomalies.• risk of recurrence of isolated (ie, nonsyndromic) congenitaldiaphragmatic hernia in future siblings is approximately 2%.• Familial congenital diaphragmatic hernia is rare (< 2% of allcases), and both autosomal recessive and autosomaldominant patterns of inheritance have been reported.• a recognized finding in Cornelia de Lange syndrome• occurs as a prominent feature of Fryns syndrome, anautosomal recessive disorder with variable features, includingdiaphragmatic hernia, cleft lip or palate, and distal digitalhypoplasia
Mortality/Morbidity• "hidden mortality" for this condition, which refers to infantswith congenital diaphragmatic hernia who die in utero orshortly after birth, prior to transfer to a surgical site• population-based study from Western Australia indicated thatonly 61% of infants with congenital diaphragmatic hernia arelive born– nearly 33% of pregnancies that involved a fetus with congenitaldiaphragmatic hernia were electively terminated– most of the pregnancies (71%) were terminated because of thepresence of another major anomaly Mortality after live birth is generally reported to range from 40-62%, presence of associated anomalies has consistently been associatedwith decreased survival; other associations with poor outcome includeprenatal diagnosis, prematurity, low birth weight, andearlypneumothorax
• Keller et al found that infants with congenital diaphragmatichernia who have poor outcomes (death or discharge onoxygen)– have higher plasma levels of endothelin-1, which is dysregulated inpulmonary hypertension.– Severity of pulmonary hypertension was also associated withincreasing endothelin-1 levels. Most studies report that congenital diaphragmatic hernia occursequally in males and females. usually a disorder of the newborn period, as many as 10% of patientsmay present after the newborn period and even during adulthood Outcome in patients with late presentation of congenitaldiaphragmatic hernia is extremely good, with low or no mortality.
Clinical PresentationCauses• diaphragm initially develops as a septum between the heartand liver, progresses posterolaterally, and closes at the leftBochdalek foramen at approximately 8-10 weeks gestation• herniation of viscera in severe congenital diaphragmatichernia is believed to occur during the pseudoglandular stageof lung development.• Lung compression results in pulmonary hypoplasia that ismost severe on the ipsilateral side, although both lungs maybe abnormal• Pulmonary hypoplasia is associated with fewer bronchialgenerations, alveoli, and arterial generations.
• diaphragmatic defect occurs in the initial stages of diaphragmdevelopment, rather than in the later stages.• Fetal exposure to nitrofen causes a variable amount of lunghypoplasia.• in which 2 insults (one primarily affecting the lungs andanother primarily affecting diaphragm development)contribute to the pathophysiology of congenitaldiaphragmatic hernia.• Congenital diaphragmatic hernia may occur as anonsyndromic or isolated defect.– Less than 2% of such cases are estimated to be familial.– Pedigrees consistent with autosomal recessive, autosomaldominant, and X-linked inheritance patterns have been described.– More than 10% of infants with congenital diaphragmatic hernia havean underlying syndromic diagnosis
• 30% of infants with congenital diaphragmatic hernia, whichhas been described as part of trisomy 13, trisomy 18, trisomy21, and Turner syndrome (monosomy X). Pallister-Killiansyndrome (tetrasomy 12p mosaicism) presents with findingsthat are similar to those of Fryns syndrome, including coarsefacial features, aortic stenosis, cardiac septal defects, andabnormal genitalia. This diagnosis can only be made if akaryotype is determined based on skin biopsy findings.• Chromosome deletions on chromosomes 1q, 8p, and 15qhave been reported in association with congenitaldiaphragmatic hernia. Deletions of chromosomes 8p and 15qappear to be associated with heart malformations.• Deficiencies in vitamin A availability, metabolism, andsignaling have been found to contribute to the developmentof congenital diaphragmatic hernia in animal models and mayalso be relevant in human fetal development
Congenital cystic adenomatoid malformation (CCAM)• is a rare abnormality of lung development. CCAM is a cysticarea within the lung that stems from abnormalembryogenesis. An adenomatous overgrowth of the terminalbronchioles with a consequent reduction in alveolar growthoccurs.• pulmonary hypoplasia may lead to the postnatal developmentof respiratory distress; may be due to pulmonaryhypoplasia, mediastinal shift,spontaneouspneumothorax, and pleural effusions secondary to hydrops.• Polyhydramnios has also been associated with CCAM =elevated intrathoracic pressure that leads to esophagealcompression and the inability to swallow
• Cases are typically identified prenatally by routineultrasonography screening. Most postnatally identified casespresent in the newborn period. CCAM may present in theolder child and adult as an incidental finding or secondary torepeated infectionSsx• Respiratory distress• recurrent pulmonary infections due to bronchialcompression, air trapping, and inability to clear secretions.• Hemoptysis• Dyspnea and chest pain (a feature of pneumothorax, whichhas been described as a presenting feature of CCAM.)• Cough, fever, and failure to thrive have all been reported inassociation with the presentation of CCAM.
• Tachypnea: Tachypnea is the most common sign encounteredin the newborn period, reflecting respiratory distress.• Pneumothorax/air trapping: Signs consistent with apneumothorax or air trapping may be elicited, includingtracheal deviation, which indicates mediastinal shift, shiftedheart sounds, and decreased air entry on the affected side.• Cyanosis• Accessory muscle use• Grunting• Failure to thrive• Chest radiography (usual appearance is of a mass containingair-filled cysts, evident include mediastinal shift, pleural andpericardial effusions, and pneumothoraces)• CT scanning of the thorax (typical appearance is ofmultilocular cystic lesions with thin walls surrounded bynormal lung parenchyma)
• Prenatal ultrasonography (may demonstrate evidence ofhydrops, such as fetal ascites or pleural effusions• Type I lesions (see Histologic Findings) appear as multiplelarge cystic areas in the lung. In type II lesions, multiple smallcysts are evident on ultrasonography.• Perform echocardiography in all newborns with CCAM to ruleout any coexisting cardiac lesions. Furthermore, in infantswith respiratory distress, echocardiography may provideevidence of persistent pulmonary hypertension (eg, right-to-left shunting, increased pulmonary artery pressures).Tx• Surgical intervention is the mainstay of therapy for CCAM