What is the recommended prenatal diagnosis and management approach for a fetus diagnosed with bronchopulmonary sequestration?

Prenatal Diagnosis and Management of Fetal Bronchopulmonary Sequestration

Diagnostic Approach

Bronchopulmonary sequestration (BPS) should be diagnosed prenatally via ultrasound by identifying an echogenic lung mass with arterial blood supply from a clearly identifiable systemic artery (typically the descending aorta) rather than the pulmonary artery. 1, 2

Key Diagnostic Features

• Ultrasound findings: Look for an echogenic intrathoracic mass with Doppler demonstration of systemic arterial supply, most commonly from the thoracic or abdominal aorta 1, 2
• Calculate the CVR (congenital cystic adenomatoid malformation volume ratio): This measurement predicts risk of complications—CVR >1.6 is associated with significantly higher rates of hydrops (58.3%) and postnatal respiratory symptoms (83.3%) compared to CVR ≤1.6 2
• MRI can be used when ultrasound findings are equivocal or to better characterize the lesion and associated complications, particularly in cases of suspected torsion with tension hydrothorax 3
• Serial monitoring: Perform ultrasound surveillance every 2-4 weeks to assess for development of pleural effusion, hydrops fetalis, or spontaneous regression 1, 2

Management Algorithm

For BPS Without Pleural Effusion or Hydrops (70% of cases)

Expectant management is appropriate, as spontaneous regression occurs in approximately 65% of cases without intervention. 2, 4

• Continue serial ultrasound monitoring every 2-4 weeks until delivery 1, 2
• Deliver at term (median 38-39 weeks) at a tertiary center with pediatric surgical capability 1, 2
• Approximately 55% will require postnatal sequestrectomy despite prenatal regression 2, 4
• Even when complete prenatal regression occurs, neonatal pleural effusion can recur rapidly after birth, requiring close postnatal monitoring and potential early surgical intervention 5

For BPS With Large Pleural Effusion or Hydrops (30% of cases)

Fetal intervention is indicated for large unilateral pleural effusions causing hydrops fetalis, with ultrasound-guided laser coagulation of the feeding artery being superior to pleuroamniotic shunting. 6, 7, 4

First-Line Intervention: Laser Ablation of Feeding Vessel

• Ultrasound-guided laser photocoagulation of the systemic feeding artery achieves complete regression in 80% of cases, compared to 0% with shunting 4
• Allows delivery at term (median 39 weeks) versus preterm delivery with shunting (median 37 weeks) 4
• Reduces need for postnatal surgery to 20% compared to 83% with shunting 4
• All cases requiring intervention should be referred to a tertiary fetal treatment center with expertise in fetal therapy 6, 7

Alternative: Thoracoamniotic Shunting

• Consider needle drainage or thoracoamniotic shunt placement for large unilateral pleural effusions when laser ablation is not available or technically not feasible 6, 7, 1
• If gestational age is advanced (near term), consider needle drainage immediately prior to delivery rather than shunt placement 6, 7
• Shunting can improve survival to >50% in cases with hydrops, but does not typically result in complete regression of the BPS 6, 4

Prenatal Steroid Therapy

• Multiple courses of maternal corticosteroids (betamethasone 12.5 mg IM every 24 hours for 2 doses) may be attempted for recurrent pleural effusions, though efficacy is variable and effusion may recur postnatally despite prenatal resolution 5
• Standard antenatal corticosteroids for fetal lung maturation should be administered between 24-34 weeks if preterm delivery is anticipated 6

Postnatal Management

Immediate Neonatal Period

• Deliver at a tertiary center with neonatal intensive care and pediatric surgical capabilities 6, 1
• Close monitoring in first 24-48 hours is critical, as pleural effusion can recur rapidly even after complete prenatal regression 5
• Be prepared for immediate thoracentesis or chest tube placement if respiratory distress develops 5

Surgical Timing

• Asymptomatic neonates: Elective sequestrectomy can be performed at 3-6 months of age or deferred with close follow-up 1, 2
• Symptomatic neonates: Early total resection (within days to weeks) is indicated for persistent or recurrent pleural effusion, respiratory distress, or feeding difficulties 5
• Surgical outcomes are excellent with minimal morbidity when performed at experienced centers 1, 2

Critical Pitfalls to Avoid

• Do not assume prenatal regression means no postnatal intervention will be needed—approximately 55% still require surgery, and effusions can recur rapidly after birth 5, 2
• Do not delay referral to a fetal treatment center when CVR >1.6 or any pleural effusion develops, as hydrops can develop quickly 2, 4
• Do not use pleuroamniotic shunting as first-line therapy when laser ablation is available, as outcomes are significantly inferior 4
• Do not perform multiple prenatal interventions without considering early delivery if near viability, as repeated procedures carry cumulative risks 5