INTRODUCTION — Congenital diaphragmatic hernia (CDH) is a developmental defect of the diaphragm that allows abdominal viscera to herniate into the chest. Affected neonates usually present in the first few hours after birth with respiratory distress that can range from mild to life-threatening. With improvements in antenatal diagnosis and neonatal care, survival has improved. However, infants with CDH continue to have a considerable risk of mortality and morbidity.
The clinical manifestations, diagnosis, management, and prognosis for neonates with CDH will be reviewed here. The pathogenesis, anatomy, incidence, and prenatal management of CDH are discussed separately. (See "Congenital diaphragmatic hernia: Prenatal issues".)
IMPACT ON PULMONARY DEVELOPMENT — Because herniation occurs during a critical period of lung development, clinical manifestations of CDH result from the pathologic effects of the herniated viscera on lung development. With rising severity of lung compression, there are corresponding decreases in bronchial and pulmonary arterial branching, resulting in increasing degrees of pulmonary hypoplasia. Pulmonary hypoplasia is most severe on the ipsilateral side. However, pulmonary hypoplasia may develop on the contralateral side if the mediastinum shifts and compresses the lung. Arterial branching is reduced, resulting in muscular hyperplasia of the pulmonary arterial tree, which contributes to the increased risk of pulmonary hypertension (PH) [1].
CLINICAL MANIFESTATIONS
Prenatal presentation — Many patients with CDH are identified through routine prenatal ultrasound Prenatal ultrasound can also identify other associated anomalies (eg, cardiac abnormalities). Prenatal presentation and diagnosis are discussed in greater detail separately. (See "Congenital diaphragmatic hernia: Prenatal issues", section on 'Prenatal diagnosis'.)
Postnatal findings
●Presentation – Postnatally, infants with CDH most often present with respiratory distress in the first few hours or days of life. Less commonly, a small subset of patients with CDH have minimal or no symptoms in the newborn period and present later in life. (See 'Late presentation' below.)
In patients who present as neonates, the degree of respiratory distress depends upon the severity of lung hypoplasia and the development of pulmonary hypertension (PH). Postdelivery, hypoxemia and acidosis increase the risk of PH by inducing a reactive vasoconstrictive element to the preexisting fixed arterial muscular hyperplasia component. In some cases, pulmonary hypoplasia is so severe as to be incompatible with life. (See 'Impact on pulmonary development' above and "Persistent pulmonary hypertension of the newborn (PPHN): Clinical features and diagnosis", section on 'Pathogenesis'.)
●Physical findings – Physical findings include a barrel-shaped chest, a scaphoid-appearing abdomen (because of loss of the abdominal contents into the chest), and absence of breath sounds on the ipsilateral side. In patients with a left-sided CDH, the heartbeat is displaced to the right because of a shift in the mediastinum.
●Laterality – In most cases of CDH, herniation occurs on the left. Right-sided CDH occurs in approximately 15 percent of cases and bilateral herniation in 1 to 2 percent [2-4]. There may be a higher incidence of pulmonary complications associated with right- versus left-sided CDH [3]. Bilateral herniation is associated with a high mortality rate [4].
●Associated conditions – Associated anomalies are seen in approximately 50 percent of CDH cases and include chromosomal abnormalities, congenital heart disease, and neural tube defects. (See 'Echocardiography' below and "Congenital diaphragmatic hernia: Prenatal issues", section on 'Associated fetal abnormalities'.)
DIAGNOSIS
Prenatal — Many cases of CDH are diagnosed prenatally by routine antenatal ultrasound screening. This is discussed separately. (See "Congenital diaphragmatic hernia: Prenatal issues", section on 'Prenatal diagnosis'.)
Postnatal
Chest imaging — While most infants with CDH are diagnosed prenatally, a small subset present postnatally with respiratory distress. In these infants, the diagnosis is made by chest imaging.
Chest radiograph findings include:
●Herniation of abdominal contents (usually air- or fluid-containing bowel) into the hemithorax with little or no visible aerated lung on the affected side (image 1)
●Displacement of mediastinal structures (eg, heart) towards the contralateral lung
●Compression of the contralateral lung
●Reduced size of the abdomen with decreased or absent air-containing intra-abdominal bowel
●If the CDH is right sided, the liver may be the only herniated organ, appearing as a large thoracic soft tissue mass with absent intra-abdominal liver shadow
The diagnosis may be facilitated by placement of a feeding tube, as chest radiography may show the feeding tube within the thoracic cavity or deviation from its expected anatomic course [5].
Echocardiography — All neonates with CDH should undergo echocardiography early in the postnatal course to detect any associated cardiac anomalies, evaluate ventricular function, and to assess for pulmonary hypertension (PH) (image 2A-B).
●Congenital heart disease – Approximately 10 percent of patients with CDH have associated congenital heart defects [6]. The most commonly reported defects include ventricular septal defects, aortic arch obstruction, univentricular defects (eg, hypoplastic left heart syndrome [HLHS]), and tetralogy of Fallot [6].
Infants with associated severe cardiac anomalies are at considerably higher risk for morbidity and mortality and these findings may have an impact on management decisions [6-9]. The prognosis is particularly poor for infants with comorbid HLHS. (See "Hypoplastic left heart syndrome: Management and outcome", section on 'Outcome'.)
In a study from the Congenital Diaphragmatic Hernia Study Group (CDHSG) that included >2500 patients with CDH born between 1995 and 2005, 11 percent had associated hemodynamically significant cardiac defects (excluding patent ductus arteriosus and atrial septal defects) [6]. Mortality was nearly two-fold higher among patients with versus without associated cardiac defects (59 versus 30 percent, respectively).
●PH and ventricular function – In addition to evaluating cardiac anatomy, the echocardiogram assesses ventricular function and estimates the right ventricular pressure to establish if there is evidence of PH (image 2B). The echocardiographic assessment for determining the presence and severity of PH in neonates is discussed separately. (See "Persistent pulmonary hypertension of the newborn (PPHN): Clinical features and diagnosis", section on 'Severity of PH'.)
Neonates with severe biventricular dysfunction often require extracorporeal membrane oxygenation (ECMO) therapy and have a high risk of morbidity and mortality [10,11]. (See 'Extracorporeal membrane oxygenation' below.)
LATE PRESENTATION — Infrequently, mild CDH defects present after the neonatal period. In a case series of 15 children who presented late with CDH, the mean age at presentation was 18 months (range 38 days to 10 years) [12]. The main presenting symptoms were respiratory complaints in 40 percent of patients, gastrointestinal (GI) symptoms in 40 percent, and both respiratory and GI symptoms in 20 percent. One-third of the patients had failure to thrive. The diagnosis was made by chest radiography in six patients, and the other patients were diagnosed by gastrointestinal contrast series or computed tomography. Primary repair was successful in all patients and all patients were alive and clinically well at an average follow-up of two years.
DIFFERENTIAL DIAGNOSIS — The differential diagnosis of neonatal CDH includes other causes of neonatal respiratory distress, including infections (sepsis, pneumonia) and noninfectious etiologies (table 1). CDH is differentiated from these conditions by the characteristic chest radiograph finding of herniated abdominal contents into the thorax (image 1). (See "Overview of neonatal respiratory distress and disorders of transition".)
PRENATAL MANAGEMENT — The prenatal management of CDH is discussed separately. (See "Congenital diaphragmatic hernia: Prenatal issues", section on 'Pregnancy management'.)
POSTNATAL MANAGEMENT — Management of CDH encompasses:
●Preoperative medical management, consisting of stabilization of the infant’s oxygenation, blood pressure, and acid-base status, especially those with pulmonary hypoplasia and pulmonary hypertension (PH). (See 'Preoperative medical management' below.)
●Surgical repair, which includes closure of the diaphragmatic defect and reduction of the viscera into the abdominal cavity (picture 1). The severity of pulmonary impairment dictates the timing of surgery. (See 'Surgery' below.)
Preoperative medical management — The available observational evidence suggests that outcomes for infants with CDH are improved when they are managed initially with medical management, deferring surgical repair until their respiratory status and PH have improved [13-16]. Initial supportive medical management consists of mechanical ventilation, hemodynamic support, and pulmonary vasodilator therapy, if needed. Patients who are refractory to these measures may require extracorporeal membrane oxygenation (ECMO).
Initial interventions — The following interventions are initiated in the delivery room when the diagnosis is made or suspected [17]:
●Intubation and ventilation – Prenatally diagnosed patients are intubated in the delivery room. This avoids the use of oronasal positive pressure (eg, bag-mask ventilation), which can distend the stomach and compress of lungs. The aim of mechanical ventilation is to avoid high pressures to minimize lung injury. Conventional mechanical ventilation (CMV) with pressure-limited breaths is used initially in most cases, though high-frequency ventilation (HFV) may be preferred in patients with severe CDH defects, as discussed below. (See 'Ventilation' below.)
●Nasogastric tube – In the delivery room, a nasogastric tube is placed and connected to continuous suction to decompress abdominal contents and reduce lung compression.
●Arterial and venous access – The infant should have an umbilical artery catheter (UAC) placed for frequent monitoring of blood gases and blood pressure (BP). In addition, an umbilical vein catheter (UVC) is placed for administration of fluids and medications. In patients with the liver in the chest, the UVC is often difficult to position, and, therefore, once the patient is stabilized, other venous access should be obtained.
●Hemodynamic support – Hemodynamic support includes isotonic fluids and inotropic agents (eg, dopamine). The goal is to maintain BP at the upper limits of normal (ie, mean BP 45 to 55 mmHg) to minimize right-to-left shunting. In some cases, hydrocortisone may be used for neonates with refractory shock [18]. These interventions are discussed separately. (See "Neonatal shock: Management".)
●Selective use of surfactant – We use surfactant in the following clinical scenarios:
•In preterm neonates ≤34 weeks gestation with chest radiographic findings of alveolar atelectasis suggestive of respiratory distress syndrome (RDS) (see "Respiratory distress syndrome (RDS) in preterm infants: Management", section on 'Surfactant therapy').
•In newborns who underwent fetal tracheal occlusion when the release of the occlusion is less than 48 hours prior to delivery. (See "Congenital diaphragmatic hernia: Prenatal issues", section on 'Fetal endoscopic tracheal occlusion (FETO)'.)
We do not administer surfactant routinely in all infants with CDH since the available evidence suggests it does not improve outcomes in term neonates with CDH [19,20].
Ventilation — Once the diagnosis of CDH is made, patients are intubated and mechanically ventilated to prevent gastric distension and lung compression. The ventilation strategy aims to minimize trauma to hypoplastic lungs [21,22].
Conventional versus high frequency — The choice of initial ventilation modality (CMV versus HFV) depends on the severity of the CDH defect.
●Severe CDH defect (right-sided and/or thoracic liver position) – For infants with a thoracic liver position or a severe right sided CDH, we typically administer an initial FiO2 of 0.5 during the delivery room resuscitation and transition to HFV once the endotracheal tube is secured [23]. We also use HFV for neonates who are refractory to CMV. We target a mean airway pressure (MAP) of 11 to 13 cm H2O (titrated based on lung expansion on chest radiograph) and a frequency of 6 to 8 Hertz (higher frequency is used for smaller or preterm infants). (See "Approach to mechanical ventilation in very preterm neonates", section on 'Initiating and titrating HFV'.)
Although the indications for HFV are not clearly defined, the use of early HFV for this high-risk population is supported by retrospective observational data [24-26].
●Less severe defect (left-sided and abdominal liver position) – We administer an initial FiO2 of 0.3 during the delivery room resuscitation and transition to CMV as soon as the endotracheal tube is secured. CMV management consists of pressure-limited ventilation with target PIP <25 cm H2O and PEEP of 5 cm H2O, aiming for tidal volumes of 4 to 6 mL/kg. Ventilator settings can then be adjusted as needed to achieve gas exchange targets. (See "Overview of mechanical ventilation in neonates", section on 'Conventional mechanical ventilation (CMV)'.)
There are few data comparing CMV and HFV in neonates with CDH [27,28]. In a randomized trial of 171 infants with prenatally diagnosed CHD (left-sided in 87 percent), rates BPD or death were lower in those assigned to CMV compared with HFV (45 versus 54 percent); however, the finding was not statistically significant (odds ratio 0.62, 95% CI 0.25-1.55) [27]. Patients in the CMV group had fewer ventilator days (median 10 versus 13 days) and decreased need for ECMO (18 versus 30 percent). Among patients managed at non-ECMO centers, one-third of those assigned to CMV subsequently transitioned to HFV. These data support the initial use of CMV in most patients with left-sided CDH, particularly those with less severe defects. (See "Overview of mechanical ventilation in neonates", section on 'High-frequency ventilation (HFV)'.)
Gas exchange targets — Our ventilation strategy uses the minimal settings necessary to maintain preductal oxygen saturations (SpO2) >85 percent or preductal partial pressure of oxygen (PaO2) >30 mmHg. We use a strategy of permissive hypercapnia, aiming for partial pressure of carbon dioxide (PaCO2) between 45 and <65 mmHg and an arterial pH >7.25 to 7.4 [20,29,30]. Blood gases are obtained frequently to guide ventilator adjustments.
Sedation and neuromuscular blockade — Sedation is appropriate for neonates who have significant agitation and/or ventilator dyssynchrony despite efforts to optimize ventilator settings (eg, using a patient-triggered mode). The approach is generally similar to the approach used for infants with persistent pulmonary hypertension of the newborn (PPHN), as discussed separately.(See "Persistent pulmonary hypertension of the newborn (PPHN): Management and outcome", section on 'Sedation and neuromuscular blockade'.)
There may be an advantage to allowing the infant to maintain a spontaneous contribution to minute ventilation [31]. Thus, sedation should be titrated to maintain a state that preserves spontaneous respiration, if possible. Neuromuscular blocking agents are used only when necessary (eg, significant ventilator dyssynchrony despite optimization of ventilator settings and sedation).
Management of pulmonary hypertension — Management of PH includes:
●Hemodynamic support – Patients with severe PH (ie, associated with ventricular dysfunction and/or or systemic hypotension) require prompt administration of inotropic agents. The goal is to maintain BP at the upper limits of normal (ie, mean BP 45 to 55 mmHg) to minimize right-to-left shunting. (See "Persistent pulmonary hypertension of the newborn (PPHN): Management and outcome", section on 'Hemodynamic support' and "Neonatal shock: Management", section on 'Vasoactive agents'.)
●Pulmonary vasodilator therapy – A trial of pulmonary vasodilator therapy is appropriate for patients with PH that is associated with significant hypoxemia from right-to-left shunting (ie, preductal SpO2 <85 percent or pre- to postductal SpO2 differential >10 percent) despite optimizing ventilatory support and sedation [32]. Inhaled nitric oxide (iNO) is the preferred initial agent in most cases. The approach is generally similar to the management of infants with PPHN, as discussed separately. (See "Persistent pulmonary hypertension of the newborn (PPHN): Management and outcome", section on 'Inhaled nitric oxide (iNO)'.)
Although iNO has been shown to reduce the need for ECMO in neonates with other forms of PPHN, the available clinical trials and observational studies have not consistently demonstrated benefit of iNO in infants with CDH [22,33-36]. Nevertheless, it is commonly used in clinical practice since limited data and clinical experience suggests that it may avoid the need for ECMO in some infants [32].
Other pulmonary vasodilators (eg, phosphodiesterase type 5 inhibitors [eg, sildenafil], prostacyclin analogues [eg, treprostinil, iloprost], and endothelin receptor antagonists [eg, bosentan]) are occasionally used in patients with CDH to treat refractory or persistent PH [37,38]. Additional details on these agents are provided separately. (See "Pulmonary hypertension in children: Management and prognosis", section on 'Specific agents for targeted PH therapy'.)
Use of prostaglandin E1 (PGE1) has also been described as a strategy to unload the right ventricle in patients with severe PH due to CDH [38].
●Impact on timing of surgery – Surgical repair is usually deferred until there is improvement in PH (ie, at a minimum, estimated right ventricular pressure [RVp] on echocardiogram should be <80 percent of the systemic blood pressure) [39]. This is discussed below. (See 'Timing' below.)
Extracorporeal membrane oxygenation — Where available, ECMO is an option for infants who have refractory respiratory and/or hemodynamic instability despite optimal medical therapy (including ventilatory support, inotropic support, and iNO). Such patients are unlikely to survive without ECMO. ECMO is used support the patient until the lungs open and PH resolves, which may take weeks.
●Criteria – The primary indication for ECMO is failure of medical therapy [13,21,40]. Optimally, ECMO should be considered in patients who are thought to have reversible respiratory disease and PH. However, in practice, predicting the reversibility of lung disease is often not possible [41]. Thus, we generally consider ECMO an option for most neonates with refractory respiratory or hemodynamic instability, provided there are no contraindications.
In our practice, ECMO is offered to patients who meet the following criteria [42]:
•Pulmonary hypoplasia and PH that are refractory to medical management (defined as ≥1 of the following):
-Inability to maintain preductal SpO2 SpO2 >85 percent or postductal PaO2 >30 mmHg despite optimal ventilator settings and iNO
-Requiring PIP >28 cm H2O or MAP >15 cm H2O to achieve gas exchange targets
-Hypotension that is resistant to fluid and inotropic support
-Inadequate oxygen delivery with persistent metabolic acidosis
•None of the following contraindications to ECMO:
-Birth weight <2 kg
-Gestational age (GA) <32 weeks (eligibility for infants 32 to 34 weeks GA is determined on a case-by-case basis)
-Intracranial hemorrhage greater than grade I
-Underlying life-limiting condition (eg, severe chromosomal aneuploidies)
Head ultrasonography should be performed prior to placing the infant on ECMO. Intracranial hemorrhage of grade II or higher is generally a contraindication to ECMO since the hemorrhage is likely to expand with continuous anticoagulation required for ECMO.
We do not consider comorbid congenital heart disease to be a contraindication to ECMO. However, the decision must be carefully weighed in infants with severe heart defects (eg, hypoplastic left heart disease) since outcomes for these neonates are generally poor. (See 'Echocardiography' above.)
There have been reports of patients with CDH with associated cardiac disease, low-grade intracranial hemorrhage, and prematurity who have been placed on ECMO and survived [7,43-45].
●Weaning – Based upon clinical stability and tolerance to care, we will gradually increase ventilator settings, follow tidal volumes, and perform trials of decreasing the ECMO flow guided by echocardiographic findings.
If the tidal volumes remain low and lung fields are opacified on chest radiograph, we obtain chest ultrasound to assess for pleural effusions. If large pleural effusions are present, they are drained with tube thoracostomy.
Other interventions to improve lung volumes may include endotracheal tube change, bronchoscopy, and lavage to clear plugs.
Once the lungs are open, if PH persists despite these measures while attempting to wean ECMO support, we consider additional pulmonary vasodilator therapy [37,38].
After optimizing cardiorespiratory support, additional attempts are made at weaning ECMO support.
●Withdrawal – The main reasons for withdrawal of ECMO support are intracranial hemorrhage and lack of response to therapy:
•Development or extension of intracranial hemorrhage – In our practice, head ultrasounds are performed daily for the first five days and then every other day while on ECMO to detect and monitor any extension of intracranial hemorrhage. In addition, head ultrasounds are performed urgently if the neonate has seizures, change in neurologic status, or following any significant clinical event (eg, surgical repair of CDH, and episodes of hypotension or hypertension). Patients on ECMO are often sedated and obtaining an accurate neurologic clinical assessment can be challenging. Therefore, we also use video electroencephalography (EEG) and portable computed tomography (CT) to assist in decisions regarding discontinuation of ECMO when the findings on ultrasound are equivocal.
•Poor response to therapy – In a small subset of patients with severe pulmonary hypoplasia and PH, there is no response to therapy of any kind, including to ECMO. In this group, support is often withdrawn. In our practice, we utilize a step-wise approach of interventions to improve pulmonary function and do not set an arbitrary time for PH resolution [46]. The decision to withdraw ECMO support in this setting is individualized and made in collaboration with the multidisciplinary care team and parents/caregivers.
●Efficacy – The efficacy of ECMO for neonates with severe PH due to CDH is supported by observational studies that suggest survival among these severely affected infants has improved since the use of ECMO was introduced [41,43,47-50]. It is important to recognize that outcomes for infants managed with ECMO vary depending on the selection criteria used, which can vary by institution. Indeed, as selection criteria have become less restrictive, reported rates of survival for infants with CDH managed with ECMO have declined somewhat. The likely explanation for this finding is that more recent cohorts represent a higher-risk population. In a report from the Extracorporeal Life Support Organization (ELSO) registry on the use of ECMO in infants with CDH over a 25-year period, survival declined from 62 percent in the earlier era (1986 to 1990) to 49 percent in the later era (2006 to 2010) [51]. The trend was attributed to changes in selection criteria for ECMO and inclusion of more high-risk patients in the later era.
Data supporting the use of ECMO in patients with PPHN more broadly are discussed separately. (See "Persistent pulmonary hypertension of the newborn (PPHN): Management and outcome", section on 'Extracorporeal membrane oxygenation (ECMO)'.)
Surgery
Timing — With a better understanding of the pathophysiology and variation in the degree of pulmonary impairment, the timing of surgery has shifted from early surgical intervention to delaying surgical correction until the patient has been stabilized medically [20]. The timing of surgery depends on the severity of pulmonary impairment:
●Patients without pulmonary hypoplasia or PH – For patients with only mild symptoms on minimal support, in whom there is no evidence of PH or pulmonary hypoplasia, repair is typically undertaken at 48 to 72 hours of age.
●Patients with reversible PH (not requiring ECMO) – For patients with mild to moderate pulmonary hypoplasia and reversible PH, the timing of repair is delayed until PH is resolved and pulmonary compliance improves [39,52]. The time course is variable and depends on the response to medical management (stabilization of blood pressure, oxygenation, and correction of acidosis). Most patients in this category demonstrate initial lability, but then stabilize, allowing repair after 5 to 10 days. (See 'Initial interventions' above and 'Ventilation' above.)
For patients with CDH who do not require ECMO, the timing of surgery does not appear to be an independent predictor of mortality after adjusting for confounding factors. This was demonstrated in a report from the CDHSG registry that included 1385 neonates with CDH who did not require ECMO; 40 percent underwent repair in the first three days after birth, 40 percent underwent repair on day of life 4 through 7, and 20 percent underwent repair after day 7 [53]. Crude mortality rates were lowest for those repaired on day of life 0 to 3 (4 percent) and highest for those repaired after day of life 7 (12 percent). However, after adjusting for other factors (birth weight, CDH defect size, liver location, comorbid cardiac defects, need for pulmonary vasodilator therapy, and type of repair [primary versus patch]), timing of surgery was not independently associated with mortality risk (odds ratio 1.4, 95% CI 0.8-2.6).
●Patients who require ECMO – For infants with severe pulmonary hypoplasia and severe PH who require ECMO, the optimal timing of operative repair is uncertain.
•Surgical repair while on ECMO – In our center, early surgical repair on ECMO is performed selectively in the following circumstances:
-When ventilation prior to ECMO is very poor. Infants in this category are unlikely to be successfully weaned off ECMO without repair.
-When ECMO flow is compromised by the degree of mediastinal shift. In this setting surgical repair is performed to allow adequate ECMO support.
Other centers advocate for early repair in all cases once ECMO is initiated [54-56].
The main disadvantage to early repair on ECMO is that it increases the risk of bleeding complications, which may contribute to mortality [57-59]. Strategies to reduce bleeding complications include perioperative use of aminocaproic acid [54,60], putting fibrin glue on the suture line [61], and avoiding extensive dissection of the diaphragmatic leaves. The downside of using aminocaproic acid is that it may cause thrombosis in the circuit. If this occurs, it may be possible to decannulate the infant without significant clinical compromise.
•Deferring surgery until off ECMO – In our center, we generally favor a strategy of deferring surgery until after the infant’s pulmonary status has improved, PH has resolved, and they are off ECMO. This strategy is used for neonates who demonstrate improvement in pulmonary status and tolerate ECMO weaning. It is also used if the neonate experiences an ECMO-related thrombotic, infectious, or mechanical complication that necessitates discontinuation of ECMO.
We prefer this approach, when possible, because it is associated with lower risk of bleeding complications, shorter duration of ECMO, and possibly improved survival [62-64]. This strategy is particularly effective for neonates who demonstrate a transient period of adequate gas exchange prior to going on ECMO, which occurs in approximately one-half of cases.
Reported survival rates in newborns with CDH managed with this approach of preoperative stabilization, selective use of ECMO, and delayed surgical correction range from 70 to 92 percent [13-16,20,63]. In a retrospective review of 74 patients with CDH managed with ECMO at our center, 55 percent were repaired during ECMO, 23 percent were repaired after decannulation, and 22 percent did not survive to repair [63]. Of patients who underwent repair, survival was higher among those repaired after decannulation (100 versus 44 percent, respectively). Major operative bleeding occurred in 29 percent of patients who underwent repair on ECMO; none of the patients repaired after decannulation experienced major bleeding complications.
Primary versus patch repair — Surgical repair consists of reduction of the abdominal viscera and primary closure of the diaphragmatic defect (picture 1). The size of the defect determines the type of repair. If the diaphragmatic defect is relatively small, it may be repaired with sutures alone (primary repair). For patients with large CDHs, a Gore-Tex patch or split abdominal wall muscle flap repair is often required since primary repair in these patients would create excessive tension and would compromise thoracic compliance [65,66].
(See 'Long-term complications' below.)
If the abdominal wall is difficult to close following reduction of the hernia, the use of a temporary abdominal wall silo or patch may be helpful [67]. In a retrospective review of CDH repairs at a single institution, delayed abdominal wall closure was required in 9 percent of all repairs, including 2 percent of repairs off ECMO, and 40 percent of repairs on ECMO [68]. Delayed abdominal wall closure was associated with an increased need for blood transfusions, higher mortality risk, and longer duration of hospitalization, and higher mortality risk.
Perioperative complications — Perioperative complications of CDH repair include:
●Exacerbation of PH, which may require ECMO support in some cases [69-71].
●Bleeding – The risk is greatest for those who undergo repair while on ECMO, particularly if chest wall closure is delayed [68].
●Infection – The risk of surgical wound infection is highest in patients who undergo patch closure. The muscle flap is a good alternative when the patient has already had infectious complications, since this approach avoids the use of prosthetic material. Other perioperative infectious complications include sepsis and urinary tract infection) [72].
●Chylothorax. (See "Approach to the neonate with pleural effusions", section on 'Iatrogenic'.)
Long-term complications after repair (eg, pulmonary impairment, gastroesophageal reflux, feeding difficulties, poor growth, developmental delay, scoliosis, chest wall deformities, CDH recurrence) are discussed below. (See 'Long-term complications' below.)
FOLLOW-UP — Because of the associated morbidities (ie, pulmonary complications, neurodevelopmental delay, gastroesophageal reflux, hearing loss, and poor growth), follow-up care after discharge from the hospital is critical. Structured follow-up, often involving a multidisciplinary team, facilitates recognition and treatment of these complications. (See 'Long-term complications' below.)
Follow-up care is tailored to the individual and depends on the type of repair (primary versus patch) and the infant’s clinical course during the initial hospitalization. Follow-up generally includes the following [73]:
●Measurement of growth parameters – Weight, length/height, and head circumference should be measured at each routine visit. (See "Care of the neonatal intensive care unit graduate", section on 'Monitoring growth' and "Normal growth patterns in infants and prepubertal children".)
●Chest radiography – Performed at follow-up visits if a patch was used in repair of the defect or if there are respiratory or gastrointestinal symptoms.
●Pulmonary function testing – Performed as clinically indicated. (See "Overview of pulmonary function testing in children".)
●Respiratory syncytial virus (RSV) prophylaxis, as discussed separately. (See "Respiratory syncytial virus infection: Prevention in infants and children".)
●Echocardiography – Performed at follow-up visits if the pre-discharge echocardiogram showed evidence of pulmonary hypertension or other clinically significant abnormalities and/or if the infant has persistent supplemental oxygen requirement. (See "Pulmonary hypertension in children: Classification, evaluation, and diagnosis", section on 'Echocardiography'.)
●Brain imaging – Neuroimaging (typically with magnetic resonance imaging) should be performed prior to discharge if there were earlier concerning findings on head ultrasound, if the infant has abnormal neurologic findings (seizures, abnormal examination), or if there are other risk factors for long-term neurodevelopmental impairment (eg, patch repair, use of extracorporeal membrane oxygenation [ECMO]). The subsequent need for neuroimaging is determined based upon the findings of pre-discharge imaging and the infant’s clinical status. (See "Care of the neonatal intensive care unit graduate", section on 'Neurodevelopment'.)
●Hearing screening – This includes newborn hearing screening prior to discharge and formal audiologic testing performed at least once by age 9 months. If these are normal, the patient should have on-going hearing assessments at regular intervals throughout childhood, according to recommendations for the general pediatric population. (See "Screening the newborn for hearing loss" and "Hearing loss in children: Screening and evaluation", section on 'Screening for hearing loss in children'.)
●Developmental screening – All infants who have undergone repair of CDH warrant close neurodevelopmental surveillance. (See "Care of the neonatal intensive care unit graduate", section on 'Neurodevelopment' and "Developmental-behavioral surveillance and screening in primary care".)
●Oral feeding assessment – If there are clinical concerns for oral feeding difficulties and/or aspiration, an oral feeding assessment should be performed by a speech-language pathologist or occupational therapist. Additional testing, if needed, is based on the findings of the clinical assessment. (See "Neonatal oral feeding difficulties due to sucking and swallowing disorders", section on 'Feeding assessment' and "Aspiration due to swallowing dysfunction in children", section on 'Clinical feeding evaluation'.)
●Evaluation for gastroesophageal reflux – Performed if there are concerning symptoms. The evaluation may include upper gastrointestinal contrast fluoroscopy, pH probe, and/or esophagoscopy. (See "Clinical manifestations and diagnosis of gastroesophageal reflux disease in children and adolescents", section on 'Available diagnostic techniques'.)
●Assessment for scoliosis and chest wall deformity – Children who have undergone CDH repair should undergo regular assessments for signs of scoliosis and chest wall deformity. This generally consists of physical examination of the spine and chest wall. Radiographic imaging is obtained with there are concerning findings on examination. (See "Adolescent idiopathic scoliosis: Clinical features, evaluation, and diagnosis", section on 'Scoliosis screening'.)
OUTCOME
Survival — The postnatal survival rate at tertiary centers has improved, with reported survival rates in the contemporary era ranging from 70 to 92 percent [74-80]. The improved survival has been attributed to improvement in prenatal diagnosis and changes in postnatal management (ie, the shift from early surgical intervention to intensive preoperative supportive care aimed at avoiding lung injury, followed by surgical correction once the neonate’s clinical status is stabilized). (See "Congenital diaphragmatic hernia: Prenatal issues", section on 'Prenatal diagnosis' and 'Preoperative medical management' above.)
It is important to recognize that most of the data on survival rates for CDH come from studies that included infants born or transferred to tertiary care centers with available skilled personnel and access to advanced technology (eg, extracorporeal membrane oxygenation [ECMO]). These survival rates do not account for fetal deaths due to CDH, pregnancy termination, or infants who presented to nontertiary centers and did not survive transport [76,81-85]. In two nationwide studies from France and Sweden, the survival rate for CDH was approximately 55 percent when accounting for fetal deaths [85].
Risk factors for mortality include [78]:
●Prematurity and low birth weight – Survival is lower for preterm infants with CDH compared with term infants, and survival decreases with decreasing gestation [86,87]. This was illustrated in a review from the Congenital Diaphragmatic Hernia Study Group (CDHSG, formerly called the CDH Registry) that reported a survival rate of 54 percent for preterm infants compared with 73 percent observed in term infants [86]. Preterm infants were less likely to undergo surgical repair (69 versus 86 percent) and be treated with ECMO (26 versus 33 percent). Survival was higher in preterm infants who underwent surgical repair (77 percent), but this was still lower than in term infants with surgical repair (85 percent). Preterm infants were also more likely to have chromosomal abnormalities (8 versus 4 percent) and major cardiac defects (12 versus 6 percent).
●Defect size – Infants with very large defects have a poorer outcome [74,88-91]. Reports from the CDHSG from 2007 and 2016 demonstrated that defect size is the most reliable predictor of survival [74,88]. Patients diagnosed prenatally have larger defects and consequently have higher morbidity and mortality [92].
●Laterality of the CDH lesion – Right-sided lesions are usually larger and often require a patch or muscle repair [3,93-97]. However, several large case series have reported similar mortality rates for right- versus left-sided lesions despite the difference in size of defect [3,93,96,97]. Bilateral herniation is associated with a high mortality rate [4].
●Associated cardiac abnormalities – Data from the CDHSG showed that patients with major complex cardiac defects (eg, single ventricle physiology, obstructive left heart lesions, and transposition of the great arteries) have a significantly lower survival rate (36 percent) compared with those with either minor heart defects (67 percent) or no heart defect (73 percent) [98].
●Persistent and severe pulmonary hypertension (PH) [69-71,93].
●Need for ECMO [51].
●Site of care and need for transport – Institutions with greater hospital and surgical volume of caring for infants with CDH have better outcomes with lower mortality and fewer days on mechanical ventilations [99]. In addition, neonatal transport of infants with CDH is associated with poorer survival compared with infants who are inborn at a tertiary center with expertise in the management of CDH [100,101]. As a result, delivery of an affected fetus should be performed at a tertiary center, preferably with ECMO capability. (See "Congenital diaphragmatic hernia: Prenatal issues", section on 'Delivery'.)
●Poor gas exchange in the early postnatal period – Survival is poorer in infants whose highest recorded preductal oxygen saturation is <85 percent in the first 24 hours of life compared with those with higher levels [102,103]. In addition, elevated arterial blood gas PaCO2 (partial pressure of carbon dioxide) >60 mmHg is associated with decreased survival [103-105].
Long-term complications — Late complications include chronic lung disease (CLD), recurrent hernia/patch problems, scoliosis and chest wall abnormalities, gastroesophageal reflux disease (GERD), poor growth, and neurodevelopmental sequelae [106-108].
●Readmission – Hospital readmission is common for patients who undergo surgical repair. This was illustrated by a study using the Nationwide Readmissions Database from 2010 to 2014 that reported almost all of the 511 patients identified with neonatal CDH (n = 495) were readmitted within the first year following birth hospital discharge [109]. One-third of the cohort were readmitted within 30 days of birth hospital discharge. The most common complications associated with readmission were GERD, CDH recurrence, and surgery for gastrostomy tube placement and/or fundoplication.
●CLD and recurrent pulmonary infections – Survivors, especially those treated with ECMO, are at risk for CLD and recurrent respiratory infections [110-114]. Pulmonary function tests are abnormal and the severity of impairment increases with increasing degrees of pulmonary hypoplasia and PH [113-116]. The available studies suggest that rates of CLD and PH decline after 5 years of age; however, pulmonary impairment may persist into adolescence and adulthood [117,118].
●Recurrent hernia – Reported rates of recurrent CDH following repair range from 2 to 13 percent [107,119-122]. Reherniation is usually diagnosed by chest or contrast studies prompted by respiratory or gastrointestinal symptoms. The risk of recurrence is greater for those with large defects [119]. Other reported risk factors include need for ECMO and type of repair (patch versus primary); however, it unclear if these are independent risk factors since both ECMO and patch repair are more likely with large defects [107]. In a report from our center that included 75 infants who underwent primary repair and 74 infants who underwent patch repair, the risk of recurrence of CDH was similar in both groups (4 and 3 percent, respectively) [66].
●Infection – Patches may become chronically infected, requiring removal of the patch and diaphragmatic reconstruction, preferably with native tissue [123].
●GERD – The reported incidence of GERD in patients with CDH ranges from 40 to 50 percent [124-126]. In the available case series, approximately 15 to 20 percent of patients with repaired CDH subsequently required fundoplication surgery for management of GERD [124-127].
Several anatomic factors that may contribute to the development of GERD include [128-130]:
•Disturbance of normal esophageal and gastroesophageal junction due to mediastinal shift and compression
•Shortened intra-abdominal esophagus
•Obtuse angle of His (angle at which the esophagus intersects the stomach at the cardioesophageal juncture)
•Deformation of the diaphragmatic crus by closure
•Pressure changes related to increased work of breathing
•Enlarged liver with gastric compression in cases with persistent pulmonary hypertension
•Abnormal motor tone due to neurologic impairment
●Intestinal obstruction – Obstruction secondary to adhesions occurs in 10 percent of patients with CDH [131-133]. All patients with CDH have malrotation or malfixation of the intestines, and thus, a predisposition to development of volvulus. Rates of this potentially devastating complication vary from 3 to 9 percent [132,134].
●Growth failure – Survivors with CDH are at risk of growth failure and the risk extends into late childhood and adolescence [135,136]. Risk factors include prematurity, ECMO, prolonged ventilation, and oxygen requirement at discharge [112,136-140]. Increased work of breathing, swallowing dysfunction, and GERD may also contribute to poor growth [135,136]. Affected patients may require supplemental feeding via nasogastric or gastrostomy tubes for adequate caloric intake [135,136]. Oral aversion due to GERD may also require gastrostomy feeding.
●Neurodevelopment impairment – Abnormalities detected by cranial imaging include intraventricular hemorrhage (IVH), infarction, periventricular leukomalacia (PVL), and extra-axial fluid collections. Magnetic resonance imaging (MRI) of survivors of severe CDH demonstrates delayed maturation and structural brain abnormalities including PVL and varying degrees of intracranial hemorrhage [141].
These abnormalities likely lead to long-term neurologic complications. Neurodevelopmental impairment has been reported in 30 to 80 percent of patients, and has included both motor and cognitive function [142-151]. Neurocognitive impairment and delay has been reported to persist into school age [142,143,145,152,153]. In particular, hearing loss is common, with reported prevalence of 30 to 50 percent [112,154-156].
One longitudinal study of 47 CDH survivors over the first three years of life demonstrated that most children who had early delays showed improvement in their neurodevelopmental outcome, but children with delays in all domains were the least likely to show improvement [149].
●Chest wall deformities and scoliosis – Chest deformities including pectus excavatum, pectus carinatum, and scoliosis are common, particularly in patients with repaired large CDH [117,157-159]. It remains uncertain whether the deformity is directly related to the use of a patch, or a consequence of the severity of the CDH and subsequent incongruent lung growth.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Pulmonary hypertension in children".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Basics topics (see "Patient education: Congenital hernia of the diaphragm (The Basics)")
SUMMARY AND RECOMMENDATIONS
●Pathophysiology – Congenital diaphragmatic hernia (CDH) is a developmental defect in the diaphragm that allows abdominal viscera to herniate into the chest, thereby compressing the lung and interfering with normal lung development. With increased compression of the developing lung by the herniated abdominal contents, there are corresponding decreases in bronchial and pulmonary arterial branching, resulting in increasing degrees of lung hypoplasia and pulmonary arterial muscle hyperplasia (pulmonary hypertension). (See 'Impact on pulmonary development' above.)
●Clinical manifestations – In many cases, the diagnosis of CDH is known at the time of birth based upon the prenatal ultrasound. Patients not diagnosed prenatally generally present with respiratory distress in the first few hours or days after birth. Physical examination may reveal a barrel-shaped chest, a scaphoid-appearing abdomen because of loss of the abdominal contents into the chest, and the absence of breath sounds on the ipsilateral side. (See 'Postnatal findings' above.)
Less commonly, a small subset of patients with CDH have minimal or no symptoms in the newborn period and present later in life. (See 'Late presentation' above.)
●Diagnosis – The diagnosis is often made prenatally with ultrasound examination. Among infants in whom CDH is not diagnosed in utero, the diagnosis is made by chest radiography showing herniation of abdominal contents (image 1). (See "Congenital diaphragmatic hernia: Prenatal issues", section on 'Prenatal diagnosis' and 'Chest imaging' above.)
All neonates with CDH should undergo echocardiography early in the postnatal course to detect any associated cardiac anomalies, evaluate ventricular function, and to assess for pulmonary hypertension (PH) (image 2A-B). (See 'Echocardiography' above.)
●Initial medical management – Initial management of the neonate includes the following measures (see 'Initial interventions' above):
•Intubation – All newborns with CDH are immediate intubated in the delivery room (or upon diagnosis if the neonate is diagnosed postnatally) to prevent further dilation of abdominal contents. Bag-mask ventilation is avoided since this leads to gastric distension and compression of the lung. (See 'Initial interventions' above.)
•Mehanical ventilation – The mechanical ventilation strategy should avoid high pressures to minimize lung injury. For most neonates, we suggest conventional mechanical ventilation (CMV) with pressure-limited breaths initially rather than other modalities (Grade 2C). High frequency ventilation (HFV) may be preferred for patients with more severe defects; HFV is also used for patients who fail CMV. (See 'Ventilation' above.)
•Gastric decompression – A nasogastric tube is placed in the delivery room and connected to continuous suction for decompression of the stomach and intestines. (See 'Initial interventions' above.)
•Hemodynamic support – Hemodynamic support includes isotonic fluids and inotropic agents (eg, dopamine). The goal is to maintain blood pressure (BP) at the upper limits of normal (ie, mean BP 45 to 55 mmHg) to minimize right-to-left shunting. In some cases, hydrocortisone may be used for neonates with refractory shock. These interventions are discussed separately. (See "Neonatal shock: Management".)
•Pulmonary vasodilator therapy – For patients with PH that is associated with significant hypoxemia from right-to-left shunting (ie, preductal SpO2 <85 percent or pre- to postductal SpO2 differential >10 percent) despite optimizing ventilatory support and sedation, we suggest a trial of inhaled nitric oxide (iNO) (Grade 2C). (See 'Management of pulmonary hypertension' above.)
The approach to using iNO in this setting is similar to the management of neonates with PH due to other causes, as discussed separately. (See "Persistent pulmonary hypertension of the newborn (PPHN): Management and outcome", section on 'Inhaled nitric oxide (iNO)'.)
●Refractory respiratory and/or hemodynamic instability – For infants who have refractory respiratory and/or hemodynamic instability despite optimal medical therapy (including ventilatory support, inotropic support, and iNO), we suggest extracorporeal membrane oxygenation (ECMO) (Grade 2C). Specific eligibility and exclusion criteria for ECMO are provided above. (See 'Extracorporeal membrane oxygenation' above.)
●Timing of surgery – The timing of surgical repair is based upon the degree of pulmonary hypoplasia and PH (see 'Timing' above):
•Patients without pulmonary hypoplasia or PH – For patients with only mild symptoms on minimal support, we suggest early repair (typically within 48 to 72 hours after birth) (Grade 2C).
•Patients with reversible PH (not requiring ECMO) – For patients with mild to moderate pulmonary hypoplasia and reversible PH who are managed without ECMO, we suggest deferring surgery until PH is resolved rather than early repair (Grade 2C). In most cases, repair can be successfully completed after 5 to 10 days.
•Patients who require ECMO – For infants who require ECMO, the optimal timing of operative repair is uncertain. We suggest deferring surgery until after the infant’s pulmonary status has improved, PH has resolved, and they are off ECMO, if feasible (Grade 2C). However, repair on ECMO may be necessary if the defect causes significant mediastinal shift resulting in impaired ECMO flow or if the neonate’s pulmonary hypoplasia is so severe that weaning ECMO is expected to be impossible without surgical repair.
●Surgical repair – Surgical repair consists of reduction of the abdominal viscera and primary closure of the diaphragmatic defect (picture 1). The size of the defect determines the type of repair. Smaller defects may be repaired with sutures alone (primary repair. Large CDHs require patch or muscle flap repair. Potential perioperative complications include PH exacerbations, bleeding, infection, and chylothorax. (See 'Primary versus patch repair' above.)
●Outcome
•Survival – In the contemporary era, survival rates for live-born infants with CDH range from 70 to 92 percent. Risk factors for mortality include prematurity or low birth weight, large size of the defect, associated cardiac defects, severe PH, need for ECMO, birth at a nontertiary center, and poor gas exchange in the early postnatal period. (See 'Survival' above.)
•Long-term complications – Long-term complications in survivors of CDH include chronic lung disease, gastroesophageal reflux, growth failure, CDH recurrence, neurodevelopmental impairment, and chest wall deformities (pectus excavatum, pectus carinatum, and scoliosis). (See 'Long-term complications' above.)
●Follow-up – Structured follow-up, often involving a multidisciplinary team, facilitates early recognition and treatment of the associated complications. (See 'Follow-up' above.)
48 : A critical analysis of extracorporeal membrane oxygenation for congenital diaphragmatic hernia.
49 : The use of extracorporeal membrane oxygenation in infants with congenital diaphragmatic hernia.
101 : Influence of location of delivery on outcome in neonates with congenital diaphragmatic hernia.
آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟