These lesions may be detected on antenatal ultrasound or postnatal chest X-ray. The systemic blood supply must be delineated using ultrasound, CT, or MRI.

ELS is generally asymptomatic but is often detected earlier than intralobar sequestrations. Both ILS and ELS may be detected antenatally and may resolve. Symptomatic infants with large sequestrations may present with respiratory distress, feeding difficulties, or cardiac failure if the sequestered lobe is associated with significant arteriovenous or left-to-right shunting [70]. Hydrops may result from severe cardiac failure in utero, and pulmonary hypoplasia and pulmonary hypertension may be associated with large lesions, as in CCAM.

Respiratory support should be instituted as required, and the systemic blood supply defined on imaging as the first step. Surgical excision is generally advocated. The timing of surgery depends on the clinical situation. Complications such as infection and cardiovascular compromise due to shunting should be treated before resection.

As for CCAM, thoracotomy is the standard approach for pulmonary sequestrations. Thoracoscopic resection is a viable alternative due to the relatively smaller size of the lesions. A laparotomy or laparoscopic approach is required for infradiaphragmatic lesions. Additional therapeutic interventions have been reported anecdotally including radiofrequency ablation and coil embolization [77].

The anomalous systemic vessels can be fragile elastic vessels with significant blood flow. Careful dissection and meticulous control are required to prevent hemorrhage. Control of the systemic blood supply during surgery is critical especially when the origin of the vessel is on the opposite aspect of the diaphragm to the operative field (infradiaphragmatic vessel for intrathoracic lesions). A loss of control can result in retraction of the vessel out of the operative field and catastrophic hemorrhage. A crossmatch should be available for all of these neonates.

These are similar to CCAM. Neonates with severe pulmonary hypertension should be optimized medically before surgery.

CLE may be detected antenatally but is difficult to distinguish from CCAM. Postnatally there is often early respiratory distress and clinical signs suggestive of pneumothorax. A CXR may show lobar hyperinflation, mediastinal shift, and flattening of the ipsilateral diaphragm. Ultrasound can help distinguish from a tension pneumothorax, or if stable enough, CT or MRI scan will confirm the diagnosis. If the neonate is stable, then a preoperative echocardiogram should be also performed.

The primary treatment is lobectomy, which may be required on an emergent basis before a full preoperative workup can be performed. More recently, segmental lung resection has proven successful in preserving lung without an increased incidence of a recurrence [78]. Positive pressure ventilation worsens the hyperinflation, and if respiratory support is required preoperatively, then HFOV may be preferred. A chest drain should never be inserted as it may cause preferential ventilation of the abnormal lung leading to respiratory failure.

Induction of anesthesia with positive pressure ventilation may cause rapid deterioration due to air trapping. If possible, spontaneous ventilation should be maintained until one-lung ventilation has been achieved or until the chest is opened. Anesthesia should be introduced by inhalation, and lines placed while spontaneous ventilation is maintained. Muscle relaxants may be administered, but in these neonates, the inspiratory pressure should be minimized [79]. Alternatively, muscle relaxants may be avoided and intubation achieved using a combination of inhalational anesthesia, intravenous propofol with topical lidocaine (3 mg/kg) administered to the cords [54, 80]. The thoracotomy instruments and the surgeon must be ready in the event that urgent thoracotomy and decompression become necessary.

First classified in 1929, and modified in 1953, five common types of EA/TEF have been described, although it is probably more appropriate to describe the conditions anatomically [81, 82, 85] (see Fig. 10.3) (Table 10.2).

The length of the gap between proximal and distal esophagus is variable, as is the position of fistula (or fistulae) within the trachea. These anatomical variations have important implications for surgical strategy and anesthesia management. In one series, the fistula was mid-tracheal in 61 %, at or just above the carina in 33 %, cervical in 8 %, and bronchial in 1 %. There was more than one fistula in 3 % of patients [85, 86]. In the “H”-type TEF, the fistula is typically in the cervical region, whereas in EA with a proximal fistula, the fistula is usually 1–2 cm from the blind-ending upper pouch [83].

Neonates with EA/TEF are often born premature, with low birth weight (Fig. 10.4) [82]. Approximately 50 % of neonates with EA/TEF have associated anomalies, an incidence that increases with decreasing birth weight (<2,500 g) and with pure EA. In contrast, anomalies are less common in those with an isolated H-type fistula [82, 83, 87, 88]. The most common anomalies associated with EA/TEF are cardiac anomalies (29 %), followed by duodenal atresia and anorectal anomalies (14 %), genitourinary anomalies (14 %), intestinal malrotation (13 %), chromosomal abnormalities (trisomies 21, 18, and 13q deletion) (4 %), vertebral and skeletal anomalies (10 %), and specific-named associations (see below). The most common cardiac defects are atrial or ventricular septal defects or tetralogy of Fallot [88, 89] (Fig. 10.5) [90]. A right-sided aortic arch is present in 2.5–5 % of infants with EA/TEF [91].

Several disorders have been associated with EA/TEF [82]. The VATER/VACTERL association, an association of unknown etiology, is defined by the presence of at least three of the following congenital malformations: vertebral defects, anorectal anomaly, cardiac defects, TEF, renal anomalies, and limb (radial) abnormalities [90, 92, 93]. Approximately 47 % of neonates with EA have VACTERL anomalies.

VACTERL-H association is the VACTERL association with hydrocephalus, although hydrocephalus is often listed as a non-VACTERL anomaly (see above). CHARGE syndrome is an autosomal dominant disorder caused by a mutation on chromosome 7. It is associated with TEF, coloboma, cardiac defects, choanal atresia, neurocognitive and growth impairment, and genital, ear, and cranial nerve defects. Potter’s syndrome, which is associated with renal agenesis, pulmonary hypoplasia, dysmorphic facies, and Schisis association, which is associated with omphalocele, cleft lip and/or palate, and genital hypoplasia, may also be associated with EA/TEF. EA/TEF is also associated with CATCH syndrome (22q deletion that includes cardiac defects, abnormal facies, thymic aplasia, cleft palate, and hypocalcaemia). Of the trisomy syndromes [13, 20], EA/TEF is most often associated with Edwards syndrome (trisomy 18). Feingold syndrome (dominant inheritance) is similar to VACTERL syndrome but features microcephaly and learning difficulties [82]. Other syndromes associated with EA/TEF include DiGeorge sequence, Pierre Robin sequence, Fanconi syndrome, and polysplenia [58].

Non-VACTERL anomalies are being reported in association with EA/TEF with increasing frequency. Such anomalies include single umbilical arteries, genital defects, digital defects, neurologic anomalies, and respiratory tract defects [90, 94].

EA may be suspected antenatally in the presence of polyhydramnios with a small or absent gastric bubble or associated abnormalities present in the fetus. Most cases, however, present after birth. A history of polyhydramnios should prompt the pediatrician to pass a size 8–10 Fr orogastric tube immediately after birth. The tube cannot pass the upper esophagus (EA). The diagnosis is strongly suspected in the first few hours after birth if an orogastric tube cannot be passed and mucous that accumulates in the upper airway cannot be cleared by swallowing. The neonate chokes or becomes cyanosed if it attempts to feed. Aspiration pneumonia due to delayed diagnosis was common decades ago but is quite uncommon in modern medicine.

The diagnosis of EA/TEF should be confirmed on plain X-ray of the chest and abdomen. A coiled nasogastric tube will be identified in the upper third of the esophagus (level T2–T4); air in the gastrointestinal tract indicates the presence of a distal TE fistula. A gasless gastrointestinal tract suggests the absence of a distal fistula, although a proximal fistula remains a possibility. Other abnormalities such as vertebral anomalies (usually in the lower thoracic region) or the “double bubble” of duodenal atresia can also be detected on preoperative films. A thorough clinical examination is important to exclude associated anomalies and the presence of coexisting problems, such as respiratory distress syndrome in premature infants. An echocardiogram is strongly recommended before surgery to identify cardiac defects and the position of the aortic arch. If the neonate has passed urine (thus excluding bilateral renal agenesis), then a renal US can be delayed until after surgery.

An H-type TEF is infrequently detected in the neonatal period but should be suspected with a history of recurrent chest infection due to repeated aspiration.

It is helpful to stratify neonates with EA/TEF according to risk. The original stratification by Waterson was based on birth weight, associated anomalies, and the presence of pneumonia [83]. Neonatal care has improved leading to a current risk stratification that is based solely on birth weight and the presence of cardiac anomalies [88, 89, 95]. Improved outcomes have resulted in survival rates exceeding 98 % in neonates with birth weights >1,500 g and without major cardiac anomalies, 82 % with birth weights <1,500 g or major cardiac anomalies, and 50 % with birth weights <1,500 g and major cardiac anomalies [95]. A four-part classification has been suggested more recently, with prediction of 100 % survival in neonates with birth weights >2,000 g without cardiac anomalies and 40 % survival in high-risk neonates with birth weights <2,000 g with major cardiac anomalies [89]. The premature infant with a major cardiac anomaly remains a high risk. Parents of infants with bilateral renal agenesis or major complications of prematurity such as grade IV intraventricular hemorrhage should be given the option of nonoperative treatment.

Initial management of neonates with EA/TEF is to prevent aspiration of oral secretions before definitive surgery. A 10Fr double-lumen oro-esophageal Replogle tube should be inserted into the upper pouch and placed on continuous suction, or secretions should be cleared frequently by naso-esophageal tube suction. The neonate should be given maintenance intravenous fluids and nursed 30° head up or in the decubitus position. Blood should be crossmatched and available for surgery. If preoperative ventilation is required, inspiratory pressures should be kept to a minimum, if possible placing the tip of the tracheal tube distal to the fistula (see below). Premature infants should receive surfactant according to standard protocols.

The aim of surgery is to restore continuity of the esophagus and ligate the TE fistula, if present. Surgery is usually performed on the first or second day of life if the neonate is stable and does not require respiratory support. Primary esophageal anastomosis is usually possible in EA with distal TEF, although it may be preferable to divide the fistula and place a feeding gastrostomy in a neonate with severe comorbidities such as a duct-dependent cardiac anomaly. Primary esophageal repair can be performed 6–12 weeks after cardiac surgery.

Emergency surgery may be required if the child requires preoperative ventilation, as in the case of the preterm neonate with respiratory distress syndrome. If the lung compliance is poor, gas from the ventilator may preferentially enter the gastrointestinal tract via the fistula. This may lead to gastric distension, deteriorating cardiorespiratory status, and possible gastric rupture. Inadvertent intubation of the fistula must be excluded in cases of severe gastric distention with cardiorespiratory instability [96]. To prevent gastric distention from ventilation via the fistula, some have recommended clamping the distal esophagus as soon as the chest is opened [97]. Decompressive gastrostomy should not be undertaken as a primary intervention as it will lead to a torrential gas leak via the gastrostomy and worsening minute ventilation. The child should undergo emergency transpleural ligation of the fistula, with delayed division of the fistula and possible repair of EA at 8–10 days [83].

Neonates with pure EA or EA with a proximal TEF often have a long gap between proximal and distal ends of the esophagus. A feeding gastrostomy is inserted and the length of the gap estimated radiographically at the time of surgery. If the gap is greater than the vertical height of three vertebral bodies, upper pouch suction is continued postoperatively and delayed primary closure is usually possible by about 12 weeks of age; if the gap is greater than six vertebral bodies, a cervical esophagostomy is often fashioned and the esophagus repaired at a later date. Esophageal replacement surgery is occasionally required [83].

An esophagoscopy or bronchoscopy is often performed at the start of surgery to provide absolute confirmation of the diagnosis, to assess the position of the fistula if present, and to exclude multiple fistulae [86]. A variety of techniques have been described to identify fistulae in neonates: rigid bronchoscopy, esophagoscopy, or flexible fiberoptic bronchoscopy via the tracheal tube. The advantage of using a small flexible bronchoscope is that the scope may also be used to assess the position of the tip of tracheal tube, to pass through the fistula to assist the surgeon in identifying the fistula during surgery, and to assess the airway at the end of surgery to exclude a residual blind-ending tracheal pouch and the severity of the tracheomalacia near the fistula [98].

The traditional approach to repair of EA/TEF is extrapleural via a right posterolateral thoracotomy with the neonate placed in the lateral decubitus position with a roll under the chest to facilitate surgical access. The posterior mediastinum is approached via the 4th and 5th intercostal spaces and the extrapleural route, gently compressing the right lung. The approach is delicate and time consuming but reduces morbidity from an anastomotic leak, should one occur. If a right arch is confirmed on preoperative echo, a left-sided approach should be considered and a double aortic arch may be approached via the standard right thoracotomy [91]. If the child becomes unstable, a transpleural approach may be used.

Thoracoscopic repair has become popular in specialist centers in recent years and, in expert hands, has the same complication rate as open techniques, with comparable blood gases, operating times, and reduced time in intensive care postoperatively [99–101]. Currently recommendations are based on large case series, since no randomized controlled trials have compared the two techniques [34, 35, 102]. For thoracoscopic repair, the child is placed semiprone with the right side of the chest elevated at 45° so that the structures may be easily visualized. Lung deflation is produced by CO₂ insufflation, and care should be taken to minimize hypercarbia, as described previously.

Major concerns during open or thoracoscopic surgery include accurate identification of anatomical structures and cardiorespiratory instability due to OLV and distortion of the trachea. The anesthesiologist may be asked to push on the Replogle tube to help identify the proximal esophageal pouch. Test occlusion of the fistula is good practice to ensure that the right lung can still be inflated and that a vital structure (e.g., the pulmonary artery or main bronchus) has not been clamped in error. If the neonate does not tolerate OLV, surgery may have to proceed with intermittent two-lung ventilation once the neonate recovers. This requires good communication between the anesthesiologist and surgeon. Increased FiO₂ and hand ventilation may be required, but respiratory compromise usually improves after ligation of the fistula. The integrity of tracheal repair can be checked by instilling warm saline in the chest during a sustained inflation to identify an air leak by the presence of air bubbles. The lower esophagus should not be aggressively mobilized in order to avoid devascularization, as this may cause later problems with esophageal motility. A gas leak from the upper pouch during esophageal anastomosis should raise suspicion of an upper pouch fistula. Dissection of the upper pouch helps to identify a proximal fistula, if one is present, and allows mobilization of the esophagus to minimize tension of the repair. If there is significant tension at the anastomosis, the neonate should remain paralyzed and the lungs ventilated mechanically for approximately 5 days postoperatively [83]. A transanastomotic tube (TAT tube) placed under direct vision before the anastomosis is completed facilitates early feeding and should be clearly marked to preclude accidental removal postoperatively.

Early complications at EA/TEF repair include tracheobronchomalacia (20–40 %), anastomotic leak (15–20 %), anastomotic stricture (30–50 %), and recurrent fistula (10 %) [103]. Tracheomalacia is due to abnormal cartilage in the region of the fistula and often produces a typical barking cough. In severe cases, the child may develop recurrent chest infections or “near death” episodes due to acute airway collapse, and emergency aortopexy may be required in the first few months after repair [83]. An early anastomotic leak may cause a tension pneumothorax; a chest drain should be inserted and the leak explored and repaired. Late complications include gastroesophageal reflux (severe reflux in 40 %) and recurrent chest infections, probably related to gastroesophageal reflux [82]. Long-term respiratory complications including bronchiectasis may result from aspiration, GERD, and chest wall abnormalities [104]. Both the parents and their neonate are at risk for psychological and traumatic stress (including post-traumatic stress disorder) [105]. These are long-term issues centered around feeding difficulties, multiple painful procedures and surgeries, feeding, and airway issues.

Anesthetic considerations include general factors relating to the thoracotomy or thoracoscopic surgery in neonates and the high incidence of comorbidity. Specific considerations include airway management and positioning the tracheal tube in the presence of a tracheal fistula. Selective OLV is not usually required as the surgeon can easily compress the lung to access the fistula. Every neonate should have a preoperative echocardiogram to identify the presence of a congenital heart defect that may range from a patent ductus arteriosus or ASD/VSD to a hypoplastic left heart. Failure to be aware of the presence of a congenital heart defect during one-lung anesthesia for an EA/TEF repair could lead to catastrophic complications including hypoxia, hypotension, and cardiac arrest.

The main anesthesia complications relate to inadvertent intubation of the fistula or preferential ventilation of the fistula causing gastric distension and desaturation [95, 106, 107]. As described above, the fistula may vary in position; two-thirds occur in the mid-trachea and one-third occur at or near the carina. The majority of complications have been described with large fistulae, particularly when they occur near the carina.

The traditional technique to secure the airway in these neonates has been to intubate the trachea while the neonate remains awake and maintain spontaneous respiration until the fistula was controlled. However, this is no longer recommended. A variety of anesthetic techniques and techniques of airway management have been described [82, 98, 106–109]. Most advocate inhalational or intravenous induction, according to personal preference, with muscle relaxant and gentle mask ventilation before intubating the trachea [98, 106–108].

Several approaches have been popularized to position the tracheal tube while avoiding intubating the tracheoesophageal atresia. One popular technique is to deliberately intubate the right main bronchus after general anesthesia is induced and then withdraw the tube until bilateral air entry is confirmed. This ensures the tracheal tube is below the fistula but does not prevent intubation of a large fistula at the carina [96]. Alternatively, rigid bronchoscopy (or flexible bronchoscopy after intubation) may be used to demonstrate the precise level of the fistula (or exclude multiple fistulae) and then plan the intubation strategy. If the fistula is mid-tracheal, the tip of the tracheal tube is ideally positioned just below the fistula, with the bevel facing anteriorly (to avoid ventilating the fistula since the origin of the fistula is the posterior tracheal wall) and gentle positive pressure ventilation used. If the fistula is at the carina, the tracheal tube may still be placed at the mid-tracheal level, provided the fistula is small. The tracheal tube should be fixed carefully and the position of the tube checked again after positioning for surgery to make sure that the dependent lung remains ventilated.

In the unusual situation of a large fistula at the level of the carina resulting in preferential gastric ventilation, some authors suggest passing a 2 or 3Fr Fogarty embolectomy catheter through the fistula into the stomach via the rigid bronchoscope; the balloon of the Fogarty catheter is then inflated to occlude the fistula. The tracheal tube is positioned alongside the Fogarty catheter [106]. This may not be a suitable technique if the child is very small or unstable. In such a case, the surgeon should proceed directly to thoracotomy to ligate the fistula as quickly as possible. Alternately, the chest may be opened rapidly and the distal esophagus ligated below the fistula [97]. If the stomach becomes very distended before the fistula is occluded, the tracheal tube should be disconnected intermittently to decompress the stomach via the airway.

Analgesia may be managed using an opioid-based technique such as fentanyl or remifentanil intraoperatively and morphine IV postoperatively, particularly for the child with long-gap EA who will remain ventilated postoperatively. Regional techniques using caudal catheters have been described and are most suitable for low-risk infants who are likely to be extubated in the immediate postoperative period. Many pediatric surgeons prefer a controlled extubation by anesthesia immediately postoperatively to reduce the risk/need for emergency reintubation that may damage the surgical closure.

Blood loss during surgery is usually minimal; intravenous crystalloid such as Ringer’s is ideal and fluid volume of 10–20 ml/kg is usually required. The blood glucose concentration should be measured [24]. Broad-spectrum antibiotics should be given before skin incision and continued postoperatively. Secure intravenous access should be obtained, and some prefer arterial access to monitor blood pressure beat to beat and to sample the blood gases during one-lung ventilation, particularly in infants with significant comorbidity. Neonates with cardiac disease have a greater incidence of critical events such as desaturation or the need for new inotropic support compared with those without cardiac disease as well as a 57 % mortality during the hospitalization for those with ductal-dependent congenital heart disease [87]. These data underscore the need for a preoperative echocardiogram to identify a possible cardiac defect in all neonates with EA/TEF and, if a heart defect is present, to discuss the need for central venous access. Phenylephrine should be prepared to treat a “tet spell” in a neonate with an unrepaired tetralogy of Fallot.

The diaphragm develops during weeks 4–8 from four embryological elements. A Bochdalek hernia results from failure of closure of the pleuroperitoneal canals during early embryonal life, often with early in-growth of the liver through the defect. The exact cause for CDH remains unknown but may be associated with genetic factors that lead to failure in cell migration, myogenesis and formation of connective tissue, or abnormalities of the retinoid signaling pathway, which is important in the development of the diaphragm. CDH may occur as an isolated abnormality (often associated with a mutation on chromosome 15q26) or occasionally associated with syndromes such as Pallister-Killian, Fryns syndrome, Cornelia De Lange, or Edwards syndrome [111]. Abnormal karyotyping has been reported in 16 % of neonates with CDH, in 4 % of those without anomalies, and 39 % of those with anomalies [114, 115].

The diagnosis of CDH is made by antenatal ultrasound in ~70 % of cases, due to the presence of intrathoracic bowel loops or stomach, often signaled by a history of maternal polyhydramnios [114, 116]. All cases should be referred to a specialist center. The fetus should be screened for associated anomalies and the family provided with antenatal counseling, particularly if there are features associated with a poor prognosis (see below) [117, 118]. Antenatal MRI scans may provide further prognostic information about lung volume, liver herniation, left ventricular mass, and pulmonary diameter, but is not routine [111].

Postnatally, the neonate may present with an exacerbation of their respiratory distress. Symptoms may range from mild to severe, depending on severity of the CDH. The abdomen is scaphoid as the intestine is in the chest, and breath sounds are reduced on the affected side. The diagnosis is confirmed by X-ray of the chest and abdomen, which helps differentiate from other chest pathologies such as CCAM. A nasogastric tube should be placed before imaging as this may lie or curl above the diaphragm if the stomach is in the chest. An echocardiogram should be sought to delineate associated cardiac abnormalities and to estimate the severity of the pulmonary hypertension [119]. Serial cranial ultrasound should be performed to exclude an intracranial bleed.

Despite the advances in the medical and surgical management of this condition, the overall mortality remains at 21–48 %. However, specialist centers with a large number of cases have better survival rates of up to 80 % live births [120]. Mortality in nonsyndromic infants is primarily related to pulmonary hypoplasia and pulmonary hypertension and, as surrogate markers of severity, the need for ECMO/HFOV or for patch repair [121]. Right-sided, bilateral, or large defects, a lung to head ratio of 1.0 or less, and the presence of the liver in the chest portend worse outcomes, as do prematurity, chromosomal anomalies, severe cardiac defects (particularly transposition of the great arteries or single ventricle physiology), and spinal anomalies [122, 123]. In an effort to establish a standardized scoring system, an international consensus concluded that the size of the diaphragmatic defect (as a surrogate for the severity of pulmonary hypoplasia and hypertension) and the severity of the cardiac defect may predict outcome [124]. ECMO required for more than two weeks or associated with renal complications, or persistent pulmonary hypertension for more than 3 weeks are also associated with high mortality [117, 118, 120, 121].

Morbidity associated with CDH in the longer term includes ongoing respiratory problems with recurrent infections and reduced exercise capacity compared with age-matched peers, neurocognitive defects secondary to neonatal hypoxia or intracranial hemorrhage, and visual impairment and deafness, possibly related to intensive care management. Gastroesophageal reflux is common and may require medical or surgical intervention. Recurrence rates of up to 50 % are reported in CDH especially if an initial patch repair is required. Scoliosis and chest wall deformity may also occur [111].

Prenatal treatment for CHD has been trialed with varying success. The most promising treatment is fetal endoscopic tracheal occlusion (FETO) with a balloon for babies with poor prognosis based on lung measurements. FETO prevents the egress of lung fluid from the fetal lung and improves lung growth and reduces vascular resistance. The tracheal balloon is either removed before delivery, by ex-utero intrapartum treatment (EXIT), or punctured immediately after delivery by tracheoscopy or percutaneous puncture [125, 126]. Promising results have been reported, but the complication rate is relatively high and may include previously unrecognized conditions such as tracheomegaly or bronchomegaly [127]. Premature delivery contributes to the poor outcomes of FETO [125]. In a randomized controlled trial of FETO, survival in neonates with isolated severe CDH is improved [125, 126, 128].

Medical management of CDH has changed dramatically over the last two decades, from a strategy of early emergency surgery with aggressive hyperventilation to reduce pulmonary hypertension to optimizing the cardiorespiratory status using a “gentle ventilation” strategy to minimize barotrauma that includes minimum peak inspiratory pressures, maintaining spontaneous ventilation and permissive hypercarbia followed by a planned, surgical intervention [129].

Delivery should be planned at or near a center with pediatric surgical and NICU expertise so that the optimal postnatal respiratory support and timely surgical intervention can be provided. The neonate should be allowed to mature to term to permit maximum maturation of the lung. A nasogastric tube should be passed after delivery to decompress the stomach, central and arterial access obtained, and the warming strategies commence with minimal handling. Pulmonary surfactant has not been shown to be beneficial [130].

Since most neonates require some level of ventilatory support after birth, it seems prudent to intubate their tracheas at delivery. The initial ventilation strategy (conventional or high-frequency oscillation) varies among centers in the absence of randomized controlled trials [131]. The aim should be to achieve pre-ductal SpO₂ 85–95 %, post-ductal SpO₂ >70 %, arterial pCO₂ 45–60 mmHg, and pH > 7.25. If a conventional ventilation strategy is used, the initial settings should include a peak inspiratory pressure (PIP) 20–25 cmH₂O, positive end-expiratory pressure (PEEP) 2–5 cmH₂O, and a frequency 40–60 breaths per minute with minimum required inspired oxygen to maintain the threshold oxygen saturation. Prolonged use of muscle relaxants is ideally avoided, and the neonate should be allowed to breathe spontaneously between assisted breaths. If HFOV is used, the initial settings should include a mean airway pressure 13–17 cmH₂O, frequency 10 Hz, amplitude (∆P) 30–50 cmH₂O, and I:E ratio 1:1. Hyperinflation of the lungs should be avoided (<8 ribs on unaffected side on chest X-ray).

Echocardiography should be performed to estimate the pulmonary artery pressure, direction of shunting across the arterial duct/foramen ovale, myocardial contractility, the presence of a congenital heart/vascular defect, and the response to treatment. The oxygenation index (OI) should be calculated (OI = mean airway pressure (cmH₂O) × FiO₂ × 100/PaO₂ (mmHg)). Inhaled nitric oxide (iNO) 10–20 ppm may be indicated if the OI is >20 or the pre-post-ductal oxygen saturation difference is >10 %. The use of iNO is controversial and response should be assessed using echocardiography. Prostacyclin or prostaglandin E1 (PGE1) should be considered if there is no response to iNO. Many units use PGE1 routinely to prevent closure of the arterial duct and to off-load the right ventricle. Sildenafil or milrinone may be indicated if pulmonary hypertension is refractory to treatment or persistent [132], but may cause systemic hypotension [130]. Endothelin receptor antagonists (bosentan) and tyrosine kinase inhibitors (imatinib) are currently under investigation. Fluid boluses may be required if peripheral perfusion is poor or hypotension is present. If cardiovascular instability persists, inotropes may be required to increase the mean arterial pressure to the upper normal range in order to reduce right to left shunting across the arterial duct.

Venoarterial extracorporeal membrane oxygenation (ECMO) may be offered in some centers as temporary stabilization and support in cases of severe cardiorespiratory failure. Specific ECMO criteria vary between centers; current European criteria for ECMO include inability to maintain pre-ductal saturation >85 % or post-ductal saturation >70 %, respiratory or metabolic acidosis with a pH < 7.15, need for aggressive ventilation, or refractory systemic hypotension [133]. The neonate should be >2 kg and >35 weeks gestation, have no lethal congenital abnormalities, have no irreversible organ dysfunction (including neurological injury), and have no contraindication to systemic anticoagulation.

The objectives of surgery in the management of CDH are to reduce the herniated contents safely into the abdomen and repair the defect. Ideally, surgery should be delayed until the neonate is stable, that is, off inotropes (with the possible exception of dopamine) for 24 h. Some have used “stability” criteria to determine the neonate’s eligibility for surgery; however these criteria may be more appropriate for determining the timing, rather than eligibility, for surgery [134]. Surgical intervention is possible while the neonate is on ECMO, although early studies suggested that the mortality was increased because of a greater risk of bleeding. Many centers undertake surgery only after weaning the neonate from ECMO, although some have achieved acceptable mortality rates repairing CDH on ECMO by limiting the use of anticoagulants and using antifibrinolytics [135]. For large defects, a patch repair may be required as a dome shape rather than a flat repair. Surgery may be performed by using an open technique (usually laparotomy) or a minimally invasive technique.

Laparotomy via an upper abdominal transverse incision allows good access to the length of the diaphragm and can be extended easily if further access is required. The abdominal contents are reduced into the abdomen and the defect is identified. The spleen may require gentle finger reduction rather than simple traction on the gastric and colonic attachments, to avoid damage and bleeding. A hernial sac, which is present in 10–20 % of cases, is usually excised during surgery. Pulmonary sequestrations may also be found, either supra- or subdiaphragmatic, and these are also excised. The hypoplastic ipsilateral lung may be seen via the defect in the chest. The diaphragmatic rim should be mobilized and, if possible, a primary repair performed without tension using nonabsorbable interrupted sutures. If the diaphragm is deficient laterally, then the sutures should incorporate a large bite of rib or muscle to prevent recurrence. If the defect cannot be closed without tension or is very large, a patch repair is required, although this technique is associated with worse short-term and long-term outcomes. A variety of nonabsorbable materials have been used, including Gore-Tex^®, Marlex^®, Dacron^®, and Silastic^®. Nonabsorbable materials have the advantage of cost, reduced bleeding, and easy handling; however they do not grow with the child and may actually shrink over time. These materials are associated with adhesions, increased recurrence, gastroesophageal reflux, and chest wall deformities [135]. Newer biosynthetic patch materials such as collagen lattices with embedded growth factors (Surgisis^®, AlloDerm^®) are under investigation, although they may increase the risk of postoperative small bowel obstruction. Techniques that involve muscular flaps have been described, but they are time-consuming and may be associated with increased bleeding and abdominal wall deformity. Myogenic patches may be developed in the future [135]. A chest drain is not used routinely as the underwater drain may cause overdistension of the hypoplastic lung. Such a drain may be inserted at a later date if a clinically significant effusion develops. The advantage of the abdominal approach is that a Ladd’s procedure can be performed at the same time if the position of the duodenojejunal (D-J) flexure is consistent with malrotation and there is the potential for malrotation.

MIS for CDH has been reported using both laparoscopic and thoracoscopic approaches. The laparoscopic approach enables better instrument handling for the diaphragmatic repair. Reduction of contents against the pneumoperitoneum and the subsequent lack of intra-abdominal space after reduction can be challenging. The thoracoscopic approach is preferred by many and has the advantage that the pneumothorax encourages reduction and there is an excellent view of the diaphragm after reduction. The lateral suture placement can be very difficult due to the rigidity and shape of the thoracic cavity. Initial reports of thoracoscopic repair also suggested an early higher recurrence rate [136]. Right-sided CDH, CDH-associated liver herniation, and the need for patch closure may be better suited for an open procedure. As for thoracoscopic repair, carbon dioxide absorption and acidosis can be problematic during MIS [101]. For this reason, an open surgical approach is probably preferred for neonates with CDH and congenital heart disease, for those who required ECMO, or for those who have continuing systemic right ventricular pressures or require significant inotropic support [137].

It is important to avoid a “flat” diaphragmatic repair during primary or domed patch repair. When the herniated chest contents are reduced into the abdomen, the intra-abdominal pressures may increase to cause abdominal compartment syndrome. If there is evidence of significant venous congestion of lower limbs after closure, then an abdominal wall silo should be left as a laparotomy at the site of the abdominal incision, as for gastroschisis repair. This may be closed a few days later.

Management of pulmonary hypertension and pulmonary insufficiency and the timing of surgery are primary considerations in these neonates. Surgical repair should only be performed in physiologically stable neonates, ideally when inotropic support is no longer required and the neonate has been weaned off ECMO, usually at 2–6 days after birth [120]. If the child becomes unstable on transfer to or in theater before surgery begins, then surgery should be postponed. Some units perform surgery in the NICU, but it remains a contentious issue (see Chap. 13) [135].

A balanced anesthesia technique that includes opioids such as high-dose fentanyl 20–50 mcg/kg [10], muscle relaxants, and an inhalational anesthetic should be used to preclude a pulmonary hypertensive crisis. Nitrous oxide should be avoided. The ventilatory strategy should be the same as in NICU; an intravenous technique will be required if the child is receiving HFOV or remains dependent on ECMO. Invasive monitoring should be continued from the NICU, with transcutaneous carbon dioxide monitoring to supplement direct measurement of arterial PaCO₂, particularly in MIS.

Surgical repair is usually uneventful and blood loss usually limited (special precautions are required if the child remains on ECMO). Hypotension usually responds to fluid boluses of 10–20 ml/kg balanced salt solution or an increase in the infusion rates of inotropes. Hypotension in the presence of an increasing difference between the pre- and post-ductal SpO₂ values may indicate an intraoperative pulmonary hypertensive crisis. Simple interventions include increasing FiO₂, increasing depth of anesthesia, opioid administration, and correction of the acidosis that are usually effective. iNO should be available in the event of a pulmonary hypertensive crisis unresponsive to these measures. If oxygenation deteriorates intraoperatively, a pneumothorax on the contralateral (good lung) side and an endobronchial intubation must be excluded. At the conclusion of surgery, the neonate should be transferred back to the NICU; the duration of postoperative ventilation is determined by the severity of pulmonary hypoplasia and pulmonary hypertension.

Inguinal hernias occur commonly with a childhood incidence of 0.8–4.4 %. Males are affected 8–10 times more than females. Premature infants have an increased risk of hernias with an incidence of 13 % in neonates born at <32 weeks gestational age (GA) and 30 % in infants <1 kg birth weight [138]. This group also has an increased risk of complications such as obstruction and incarceration. Inguinal hernia is also associated with cystic fibrosis, connective tissue disorders, and abdominal wall defects.

Pyloric stenosis occurs in 1–3:1,000 births and is four to five times more common in males than females and more commonly in firstborn males. The etiology of pyloric stenosis has been elusive, although there is some evidence for a genetic basis for the disease, feeding practices, erythromycin exposure postnatally (or prenatally), sleeping position (prone increases the risk), and possibly infectious moieties [149–152]. The age at which pyloric stenosis presents has been gradually decreasing. Currently, most cases present at 2–5 postnatal weeks, after several days of projectile vomiting [153–155]. Pathological hypertrophy of the inner layer of smooth muscle in the pylorus results in gastric outlet obstruction, which leads to the projectile nature of the vomiting.

Pyloric stenosis is usually an isolated defect. However, in many cases, it is associated with genetic syndromes including Cornelia de Lange and Smith–Lemli–Opitz syndromes as well as chromosome 8 and 17 translocations and (partial) trisomy 9 [150].

Congenital intestinal atresia or stenosis can occur at any point along the gastrointestinal tract. The neonate presents with intestinal obstruction, the timing and specific presenting features relating to the level of the obstruction [173, 174, 265].

Pyloric atresia is an extremely rare condition (1:100,000 live births) representing 1 % of intestinal atresias. Up to 30 % of patients have other associated anomalies including epidermolysis bullosa, aplasia cutis congenita, and esophageal atresia. Presentation is with non-bilious vomiting with a single gastric bubble on abdominal X-ray and no distal gas. Surgery involves a laparotomy to either excise the obstructing membrane or perform a bypass procedure (gastroduodenostomy or gastrojejunostomy) to restore intestinal continuity. The practical considerations are similar to those for duodenal atresia.

Duodenal atresia or stenosis occurs in 1:5,000–1:10,000 live births with a male preponderance. Half of the patients have associated anomalies, commonly trisomy 21 (30–40 %), malrotation (30–40 %), and cardiac anomalies (20 %). Anorectal and genitourinary anomalies, esophageal atresia, and Meckel’s diverticulum are also associated with duodenal atresia and, more rarely, biliary anomalies. Up to 45 % of babies are born prematurely [173]. Duodenal atresia may be classified as follows (Table 10.3).

Small bowel atresia or stenosis is a common cause of neonatal intestinal obstruction occurring in 1:3,000 live births [80]. A stenosis is due to a localized narrowing of the lumen without loss of continuity in the intestine or mesentery (Fig. 10.11). Small bowel atresias are classified into four major types [175, 176] (Table 10.4).

Types II and IIIa occur most commonly. There may be a family history especially in type IIIb atresia. Multiple atresias are not uncommon, with up to 67 % of jejunal atresias and 25 % of ileal atresias having further distal atresias. Chromosomal abnormalities are much less common in the more distal atresias compared to duodenal atresia although 12 % of patients with ileal atresia will also have cystic fibrosis. These patients should have genetic screening and a sweat test performed at an appropriate time postoperatively. There is an association between gastroschisis and small bowel atresias.

This is a very rare cause of intestinal obstruction and represents <10 % of all intestinal atresias. A vascular insult is the likely cause of these atresias. These occur when closing abdominal wall defects especially gastroschises secondary to localized vascular interruption. Applying the Grosfeld classification, most are type IIIa or type I. Associated proximal atresias are common (22 %), and right-sided atresias are associated with Hirschsprung’s disease.

Meconium ileus results from the obstruction of the distal small bowel due to thick inspissated meconium. The majority (90 %) are due to intestinal and pancreatic dysfunction secondary to cystic fibrosis (CF). Up to 25 % of neonates with underlying cystic fibrosis will present with meconium ileus. Once the obstruction has been successfully treated, the infant must be tested for CF. The presence of meconium ileus does not predict a worse, long-term outcome from CF, although almost all children with meconium ileus develop pancreatic insufficiency and will require pancreatic enzyme replacement when feeds are introduced [177]. It is important to involve the respiratory physicians early, even though clinical lung disease is very uncommon in neonates.