Bronchopulmonary Sequestration (BPS)
Bronchopulmonary sequestration (BPS) is a cystic mass of nonfunctioning pulmonary tissue that receives its blood supply from the systemic circulation, according to specialists at the University Center for Fetal Medicine. There are two types of BPS: intralobar and extralobar.
BPS can be seen on a routine prenatal ultrasound. Once noted, referral to a tertiary care center is indicated for additional testing to rule out other anomalies and complications and to follow the growth of this mass.
The prenatal evaluation should include a high-resolution ultrasound, including doppler evaluation to look for a systemic blood vessel supplying the mass, and fetal MRI to define the anatomy, aid in diagnosis and rule out complications like fetal hydrops. In addition, fetal echocardiogram should be performed to rule out cardiac anomalies and evaluate cardiac function.
A MRI (right) shows a left lower intralobar sequestrian indicated by the arrow. Ultrasound doppler also demonstrated a large systemic feeding vessel arising from the descending aorta.
The growth of these masses is variable until the time of delivery. Once detected, these lesions should be followed closely throughout gestation. If there is mass effect on the mediastinum, then delivery should occur at a tertiary care center where a pediatric surgeon, neonatal intensive care unit (NICU) and extracorporeal membrane oxygenation (ECMO) are available.
Treatment of BPS varies from case to case. Fetal intervention may be needed if the fetus develops hydrops. Treatment of the fetus depends on gestational age and the type of BPS. Fetuses developing hydrops at 30 weeks or later may be considered for early delivery and resection of the mass at birth using a specialized delivery called the EXIT procedure. Fetuses with intrathoracic BPS who develop hydrops prior to 30 weeks may be candidates for fetal surgery to resect the mass, or if there is a large pleural effusion, the placement of a thoracoamniotic shunt to relieve the pressure.
Treatment also varies due to the type of lesion. The newborn should be examined thoroughly for respiratory distress. If no symptoms are present, the newborn may be able to undergo surgical resection at approximately one month of age. Newborns who exhibit symptoms will require resection of the mass in the newborn period. Recovery time and length of hospital stay depend on the condition of the baby.