What are the management options for congenital anomalies of the lungs?

Congenital Anomalies of the Lungs: Management Options

Classification and Diagnostic Framework

The management of congenital lung anomalies must begin with accurate classification using the chILD Research Network (chILDRN) scheme, which divides disorders into "Disorders More Prevalent in Infancy" and "Disorders Not Specific to Infancy." 1

Major Categories of Congenital Lung Anomalies

Diffuse Developmental Disorders include the most severe malformations 1:

• Acinar dysplasia
• Congenital alveolar dysplasia (ACD)
• Alveolar-capillary dysplasia with pulmonary vein misalignment

Growth Abnormalities encompass 1:

• Pulmonary hypoplasia (often associated with congenital diaphragmatic hernia, oligohydramnios, or thoracic dystrophies) 1
• Chronic neonatal lung disease including bronchopulmonary dysplasia
• Structural changes with chromosomal abnormalities (particularly Trisomy 21) 1
• Congenital heart disease-associated pulmonary changes 1

Congenital Parenchymal Malformations include 2, 3:

• Congenital pulmonary airway malformations (CPAM, formerly CCAM)
• Bronchopulmonary sequestration
• Congenital lobar emphysema/overinflation
• Bronchogenic cysts
• Isolated congenital bronchial atresia

Airway Structural Anomalies comprise 1, 4:

• Williams-Campbell syndrome (bronchomalacia)
• Mounier-Kuhn syndrome (tracheobronchomegaly)
• Congenital tracheal stenosis
• Tracheal agenesis

Surfactant Dysfunction Disorders include genetic mutations in 1:

• SFTPB (surfactant protein B deficiency)
• SFTPC (surfactant protein C mutations)
• ABCA3 mutations
• Thyroid transcription factor 1 (TTF-1/Nkx2.1) defects

Diagnostic Evaluation Algorithm

Initial Assessment

All patients with suspected congenital lung anomalies require chest radiography as the first-line imaging study, though it rarely provides a specific diagnosis. 1

For patients meeting chILD syndrome criteria (infants <2 years with diffuse lung disease, three of four criteria including respiratory symptoms, hypoxemia, diffuse abnormalities on imaging, or failure to thrive after excluding common causes), diagnostic testing to determine the exact diagnosis is strongly recommended. 1

Advanced Imaging

Thin-section CT scanning with controlled ventilation HRCT (CVHRCT) is suggested to optimally characterize the nature and distribution of lung disease, though this requires sedation or general anesthesia. 1 CT angiography confirms the diagnosis in the first few months of life for most congenital parenchymal malformations 2.

Chest CT is the optimum postnatal diagnostic imaging modality when chest radiography is not definitive. 5

Cardiac Evaluation

Echocardiography is strongly recommended for all patients with chILD syndrome to detect congenital cardiac anomalies, vascular anomalies, and pulmonary hypertension, as these significantly affect survival and management. 1 Approximately 40% of patients with 22q11.2 deletion syndrome have congenital heart disease, predominantly conotruncal defects 1.

Scimitar syndrome (right lung hypoplasia with anomalous pulmonary venous return) is frequently associated with pulmonary arterial hypertension and requires comprehensive cardiovascular assessment. 1

Genetic Testing

For infants presenting with diffuse lung disease and features suggesting surfactant dysfunction, genetic studies should be pursued and may precede lung biopsy if time permits. 1

Genetic testing should target 1:

• SFTPB mutations in neonates with respiratory distress syndrome pattern
• SFTPC mutations in patients with chronic pneumonitis of infancy (CPI) pattern
• ABCA3 mutations in patients with pulmonary alveolar proteinosis (PAP) variant pattern
• TTF-1/Nkx2.1 mutations

Lung Biopsy

Lung biopsy provides definitive diagnosis when non-invasive testing is inconclusive, particularly for surfactant dysfunction disorders and alveolar-capillary dysplasia. 1

Management Strategies

Surgical Management

Complete surgical resection (lobectomy) is the procedure of choice for most congenital parenchymal malformations and is the gold standard for symptomatic lesions. 5, 2

For asymptomatic congenital pulmonary airway malformations, bronchopulmonary sequestration, and bronchogenic cysts, early surgical resection is increasingly recommended to minimize risk of recurrent infections, pneumothorax, and potential malignant transformation. 2, 6 The malignant potential is particularly concerning for CPAM, where adenocarcinoma development has been documented 3.

Thoracoscopic resection is more amenable in adults with completely benign lesions, while thoracotomy may be required for complex cases. 6

Timing of surgery may be delayed in patients with bilateral lung involvement or those requiring extended respiratory support to increase pulmonary reserve. 5

Medical Management

For alveolar-capillary dysplasia, lung transplantation is the only potential route to long-term survival, as the natural history is usually relentless despite pulmonary arterial hypertension pharmacotherapy. 1

Extracorporeal membrane oxygenation (ECMO) can be used pre- and postoperatively as an adjunct in treating associated persistent pulmonary hypertension. 5

The role of pulmonary arterial hypertension pharmacotherapy in patients whose primary abnormality is developmental lung disease remains speculative and is not well-established. 1

Conservative Management Considerations

Expectant management has been suggested by some surgeons for asymptomatic lesions, as the true incidence of adverse outcomes including malignancy remains unknown. 2 However, this approach requires:

• Planned follow-up with serial imaging
• Proper transition to adult care
• Patient education about warning signs (recurrent infections, hemoptysis, pneumothorax)

Special Populations and Associated Conditions

Bronchiectasis-Associated Congenital Anomalies

Williams-Campbell syndrome and Mounier-Kuhn syndrome are diagnosed based on characteristic CT features, though data describing their incidence in adults is limited to case reports. 1

Cardiac-Associated Anomalies

When patent ductus arteriosus coexists with coarctation aortica, closure of the PDA is indicated if there is left ventricular volume overload or pulmonary hypertension, even with net left-to-right shunt. 7

Congenital heart disease patients with 22q11.2 deletion syndrome require multidisciplinary perioperative management due to increased complication risk including prolonged mechanical ventilation. 1

Critical Pitfalls and Complications

Pulmonary hypertension is the most common cause of mortality in congenital lung malformations and must be aggressively identified and managed. 5

Misdiagnosis is common in adults with congenital lung anomalies, as these lesions often mimic other thoracic pathology and may present acutely. 6

Incomplete resections in childhood may lead to recurrent presentations in adulthood, requiring reoperation. 6

KRAS somatic mutations have been confirmed in CPAM and are under investigation as mechanisms for malignant transformation. 2

Follow-Up and Monitoring

All patients require planned follow-up regardless of management strategy chosen, with proper transition from pediatric to adult care. 2

Patients with congenital heart disease require long-term cardiac follow-up, as many require reintervention in childhood or adolescence. 1

Even patients without structural heart disease may develop dilated aortic root and arrhythmias, warranting periodic surveillance. 1