Children's Hospital Colorado

Bronchopulmonary Sequestration

What is bronchopulmonary sequestration (BPS)?

Bronchopulmonary sequestration (BPS) is a mass of nonfunctioning lung tissue that does not communicate with the bronchioles, the passages that move air and in out of the lungs.

There are two types of BPS: intralobar (inside a lung lobe) or extralobar (outside of the lung with its own pleural cover). Intralobar BPS is more common, accounting for 75% of cases, and it is located in the lower lobe of the lung in 98% of cases. Extralobar BPS is usually located in the lower part of the chest, closer to the back, with about 90% of masses occurring on the left side.

Bronchopulmonary sequestration can also be intrathoracic (inside the chest) or extrathoracic (outside the chest). These masses receive blood supply from a systematic "feeding" vessel, such as the pulmonary artery, which help them grow. As they increase in size, these masses may cause amniotic fluid to accumulate in the chest or abdomen of the baby, making intervention necessary.

Who gets bronchopulmonary sequestration?

While the cause of BPS is not entirely known, there is a slightly higher chance for male babies to be diagnosed with this condition. It is not believed to be genetic, as there is no familial predisposition. Extralobar BPS is much more common in the fetus and newborn than intralobar BPS.

Bronchopulmonary sequestration may compress lung tissue or push the heart into an abnormal position. Extralobar BPS can also twist, causing surrounding blood vessels to twist as well (called "torsion"). This could cause hydrops, or fluid accumulation, to develop. The BPS may cause extra fluid to build up around the fetus, as well, which is called polyhydramnios.

In some cases, other abnormalities seen in and around the chest and upper abdomen may be associated with BPS. It is less common to see associated abnormalities in the intralobar type of BPS (only 10% of cases), but abnormalities are seen in 60% of cases of extralobar BPS. Because of its size, a BPS mass might result in incomplete development or underdevelopment of a baby's lungs, which could significantly impact the ability to breath after delivery.

How is bronchopulmonary sequestration diagnosed?

Bronchopulmonary sequestration will appear as a bright, white mass in the vicinity of a baby's lungs during routine ultrasound. There will be a clearly defined blood vessel feeding the lesion, which usually confirms the diagnosis of BPS. Usually, however, an ultrasound cannot determine if the BPS is intralobar or extralobar. Sometimes, the ultrasound will show fluid in the lungs, extra amniotic fluid or fluid in two more areas of the body, such as the skin, lungs, heart and/or abdomen (referred to as hydrops).

At least 75% of prenatally diagnosed cases of BPS become smaller spontaneously, while those associated with hydrops (fluid accumulation), pleural effusions (fluid in lung tissue) or mediastinal shift (organ movement) will require intervention during pregnancy or after delivery.

How is bronchopulmonary sequestration treated?

When a chest mass is identified, a very detailed ultrasound is needed to evaluate other potential diagnoses. An amniocentesis (a needle inserted into the amniotic sac under ultrasound guidance to remove some amniotic fluid) may be recommended to test for a genetic/chromosomal abnormality. In severe cases, a family may decide to end the pregnancy if the diagnosis is made prior to 24 weeks of pregnancy.

If the family decides to continue with the pregnancy, arrangements will be made with the Colorado Fetal Care Center team to deliver the baby at our facility. This way, both mother and baby will have access to experts in the field of fetal medicine during and after delivery. Our fetal care team will also manage any complications that may arise.

On top of delivery at our state-of-the-art facility, we also offer different options to treat a fetal BPS, depending on the severity. These treatment options include:

Fetal intervention

Fetuses who develop hydrops prior to 30 weeks of pregnancy may be at significant risk of stillbirth. In those fetuses, fetal intervention (surgical procedures performed while the fetus is still in the uterus) may be necessary. Sometimes, a tube (called a shunt) may be placed to correct hydrops and excessive amniotic fluid (polyhydramnios).

Alternatively, a laser fiber can be inserted under ultrasound guidance to close off the blood supply to a mass. Open fetal surgery may be necessary in extreme cases.

Early delivery

Fetuses beyond 30 weeks of pregnancy may be considered for early delivery followed by removal of the lesion after birth.

What to expect after delivery

Newborn babies who have been diagnosed with BPS may need vigorous stimulation and resuscitation in the minutes after birth. The greatest concern at delivery is the amount of lung development and the newborn's ability to breathe once the umbilical cord is cut. In severe cases, the baby may need to be placed on a breathing machine (ventilator) or a very specialized heart-lung machine, known as ECMO, to uniquely provide oxygen to the blood.

If there is fluid in the chest or abdomen, a tube known as a shunt may need to be placed to drain it. In many cases, babies will need surgery to remove the chest mass, but as many as 75% of cases spontaneously shrink after birth. Monitoring the mass after birth is critical to decide if removal is needed. If the mass grows, the fetal surgery specialists at the Colorado Fetal Care Center will remove it in our specifically-designed fetal surgery suite. After the baby recovers, remaining lung tissue should enlarge to fill the space left from the mass.

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