PDF | Introduction. The Congenital Diaphragmatic Hernia (CDH) is an anatomical structural defect, which allows passage of the abdominal viscera into the chest. PDF. Sections. Abstract; INTRODUCTION; RESEARCH TRENDS Congenital diaphragmatic hernia (CDH) is an anatomical defect in the. Defects involving an abnormal development of the diaphragm are referred to as congenital diaphragmatic hernias (CDH). Within this group, Bochdalek hernias.
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The purpose of this overview is to increase the awareness of clinicians regarding congenital diaphragmatic hernia and its genetic causes and. Congenital Diaphragmatic hernia (CDH) is a condition characterized by a defect in the diaphragm leading to protrusion of abdominal contents. Posterolateral Bochdalek diaphragmatic hernia in adults. Hernia diafragmática posterolateral de Bochdalek en el adulto. José Maximiliano Garófano-Jerez1,2.
A study by Noble and colleagues 13 using in vitro cells under the influence of nitrofen demonstrated a diminished efficacy of each isoform of the RADLH2 enzymes required to create retinoic acid RA. Similar to nitrofen, there are other compounds that induce a diaphragmatic defect similar to that of CDH In Wilson et al.
Babiuk RP et al.
Moreover it is still not clear if the pathologic features in the lung development pulmonary hypoplasia related to CDH surge from a primary defect in pulmonary development or from the diaphragm defect.
Thus, according to Keijzer and colleagues, two independent events contribute to the formation of pulmonary hypoplasia. Likewise, there have been similar studies with nitrofen demonstrating the dual hit hypothesis 16 , Nonetheless, this does not rule out the possibility that other pathways may contribute to the pathology of this condition. Likewise, there has been much investigation into finding the genes thought to be involved in the development of CDH, as some of the genes regulated by RA i.
Supporting this, a study in mice that induced ablation of this gene in specific tissues revealed that mice developed diaphragmatic hernia When a chromosomal anomaly is associated with CDH, these patients typically have a very poor prognosis compared with isolated CDH Deletion of 15q26 is the most frequently found of the chromosomal aberrations 20 - These patients have similar phenotypes to Fryns syndrome, presenting with growth retardation, left sided CDH, heart anomalies and specific facial features It has also been noted that when certain regions in chromosomes such as 15q Missing a copy of any of these genes could cause a diaphragm defect.
Surgically induced models The surgically induced model is when the diaphragmatic defect is surgically created.
This model has been utilized for the study of therapeutic interventions, and is often considered less informative as the procedure is typically performed on previously normal animals with normal lungs and diaphragm. One parameter is the position of the liver. Beck et al.
They measured the LHR as the ratio of the contralateral lung area to the head circumference.
The first 6 h of life of newborns are critical for predicting the outcome of the patient. It is theorized that if in the first 6 h of birth the patient does not have any symptoms then there is a reasonable lung function and therefore is likely to have higher survival rates.
Conversely, if the patient has respiratory distress within the first 6 h of birth then the patient has a higher propensity for having pulmonary hypoplasia and thus higher mortality rates Hayakawa et al. It is now known that the mortality of these infants is due to pulmonary complications related to pulmonary hypoplasia and pulmonary hypertension, and that infants initially managed with surgical repair have increased mortality rates due to these complications Currently the initial approach to the management of CDH is focused on the restoration of optimal respiratory function prior to surgical repair.
Nakayama et al. Several treatment strategies have been proposed that focus on restoring pulmonary function, either by ventilation modalities, medically with surfactant, steroids, growth factors, 32 vitamin A or with new intrauterine strategies like the fetoscopic tracheal occlusion FETO.
Chest x-ray shows visible bowel gas above the diaphragm accompanied by a mediastinal shift.
Rarely, older children or adults with inconspicuous congenital diaphragmatic defects can be suspected because of respiratory or gastrointestinal symptoms including chronic cough, recurrent pulmonary infections, pleural effusions, pneumonia, or dysphagia. Intestinal obstruction and volvulus may be presenting symptoms, as abnormalities in the usual intestinal rotation during fetal development are common.
Finally, some individuals may be diagnosed incidentally by plain chest radiographs or other imaging procedures. In these individuals, the degree of respiratory symptoms is correlated with the degree of pulmonary hypoplasia and can be limited. Clinical Manifestations Respiratory Compromise Infants with CDH often present in the neonatal period with severe respiratory distress, occasionally after a stable period of hours followed by acute respiratory distress.
Breath sounds are diminished ipsilateral to the hernia. Almost all individuals with CDH have some degree of pulmonary hypoplasia. The pathogenesis of the pulmonary hypoplasia associated with CDH appears to have both a primary component i. Evidence for the presence of a primary defect in lung development arises mostly from studies in animal models, some of which show that the lung hypoplasia precedes the herniation of abdominal viscera.
Infants with CDH typically require mechanical ventilation and sometimes extracorporeal membrane oxygenation ECMO in the newborn period. Major respiratory complications include tracheobronchomalacia, pneumothorax, and secondary lung infection especially viral pneumonia that could precipitate terminal respiratory failure even months after surgery.
Many infants require ongoing oxygen supplementation and diuretics following surgical correction of CDH. Given the remarkable growth and recuperative capacity of the lung, these treatments can usually be discontinued within the first two years of life.
By early childhood, few children have respiratory symptoms at rest; however, formal testing in older children shows small airway obstruction and diminished blood flow on ventilation-perfusion V-Q scan, especially to the lung ipsilateral to the hernia. Reduced exercise tolerance can be a lifelong problem. Intermittent wheezing requiring bronchodilator use is common in people with CDH, and they are at risk for respiratory decompensation with intercurrent illness.
Pulmonary Hypertension Abnormal pulmonary vascular development and function is a significant problem in infants with CDH. Guidelines for the diagnosis of pediatric pulmonary hypertension were set forth by the American Heart Association and American Thoracic Society [ Abman et al ]; however, individuals with CDH present a unique challenge due to very young age at the onset of PH.
The mechanism of pulmonary hypertension in CDH is not completely understood. The size of the pulmonary vascular bed is decreased in the hypoplastic lungs and the vasculature displays medial and adventitial thickening [reviewed in Harting ]. Notable is the premature differentiation of smooth muscle cells into a contractile phenotype [ Sluiter et al ]. Failure of relaxation of the pulmonary vasculature at birth is a critical component leading to pulmonary hypertension in CDH and it is the consequence of abnormal expression of both vasoconstrictors and vasodilators in distinct but converging pathways [ McCulley et al ].
Some infants and children require long-term high-calorie nutritional supplements.
The main independent predictor of intellectual disability is ECMO treatment. Later, intelligence is reported in the normal range for the majority of individuals with isolated CDH, but educational support in school is often warranted and behavioral issues such as struggling with concentration and attention are common [ Friedman et al , Peetsold et al , Ijsselstijn et al ].
Preschool motor development scores in individuals with CDH are normal or mildly reduced, and improve with age; however, nonfocal neurologic abnormalities such as hypotonia are common, as are motor problems, especially in ECMO survivors [ Nijhuis-van der Sanden et al ].
Nonspecific findings such as cortical atrophy, ventriculomegaly, and intracranial hemorrhage can be seen on neuroimaging studies [ Ahmad et al , Bouman et al , Rasheed et al ]. Musculoskeletal Chest asymmetry is found in as many as half of individuals with CDH. These musculoskeletal abnormalities occur more often following repair of large diaphragmatic defects, possibly as a result of the extra tension exerted on the chest wall during surgical repair.
The fact that SNHL is late-onset and progressive, and therefore is not present on neonatal hearing screening, makes it difficult to compare studies and provide a more precise frequency.
Prognosis Mortality. Prognostic indicators Whether the CDH is isolated or complex. Surgery ; Deslauries J. Chest Surg Clin N Am ; 8: Missed diaphragmatic injuries and their long-term sequelae.
Organ Injury Scaling IV: thoracic, vascular, lung, cardiac and diaphragm. Mansour KA, Trauma to the diaphragm. Chest Surg Clin N Am ; 7: Management of stab wounds to the thoracoabdominal region: a clinical approach. Ann Surg ; Traumatic diaphragmatic injuries: spectrum of radiographic findings.
Radiographics ; Scott JK.
Diagnostic pneumoperitoneum. Br J Dis Chest ; Diaphragmatic injury: a method for early diagnosis. Use of technetiumm albumins colloid to assess competency of hemidiaphragms in children. Clin Nucl Med ; Disruption of the diaphragmatic echoes: a sonographic sign of diaphragmatic disease. J Clin Ultrasound ; Computed tomography in traumatic defects of the diaphragm. Clin Imag ; Traumatic intrapericardial diaphragmatic hernia diagnosed by echocardiography.
Traumatic intrapericardial diaphragmatic hernia. Injury ; Traumatic diaphragmatic hernia presenting as na intercostal hernia: case report. Chicago, American College of Surgeons, Peritoneal lavage in penetrating thoracoabdominal trauma. Delayed traumatic rupture of the diaphragm in pregnancy.