OVERVIEW

What is Bronchopulmonary Sequestration?

Bronchopulmonary sequestration (BPS) refers to abnormally developed lung tissue within the lungs that lacks normal lung function but has an independent abnormal blood supply system and is not properly connected to the normal tracheobronchial tree. It is commonly referred to as "sequestered lung."

It may be accompanied by developmental abnormalities of the foregut (i.e., the esophagus and stomach) and diaphragm, hence the name bronchopulmonary sequestration.

Is Bronchopulmonary Sequestration Common?

No, it is uncommon.

For congenital pulmonary airway malformations (CPAM), the overall incidence is approximately 1/40,000 to 1/10,000. This category includes various lung airway malformations such as congenital pulmonary airway malformation (CPAM), congenital lobar emphysema, and bronchopulmonary sequestration. Therefore, bronchopulmonary sequestration is considered a rare malformation.

Is Bronchopulmonary Sequestration the Same as Congenital Pulmonary Airway Malformation?

No, they are not the same disease.

Congenital pulmonary airway malformation (CPAM) and bronchopulmonary sequestration both belong to congenital pulmonary airway malformations. CPAM is characterized by the formation of cysts of varying sizes, causing "adenomatoid" changes in the terminal bronchioles. Although the alveolar tissue in these malformations lacks normal gas exchange function, it remains connected to the tracheobronchial tree, which distinguishes it from sequestered lung.

What Are the Types of Bronchopulmonary Sequestration?

Bronchopulmonary sequestration is typically divided into two types:

• Extralobar Sequestration (ELS): Extralobar bronchopulmonary sequestration is completely independent of normal lung tissue and is enclosed by its own pleura, whereas intralobar sequestration is mixed with surrounding normal lung tissue. ELS is more common in boys than girls (approximately 2–3:1) and occurs more frequently on the left side. It may be associated with conditions such as congenital diaphragmatic hernia, spinal deformities, and congenital heart disease.
• Intralobar Sequestration (ILS): Intralobar bronchopulmonary sequestration is commonly found in the posterior basal segment of the lower lobes, with the left side being more frequently affected than the right.

SYMPTOMS

What are the common manifestations of bronchopulmonary sequestration?

Some babies are typically detected during prenatal examinations. In prenatal ultrasound, bronchopulmonary sequestration appears as a well-defined, hyperechoic homogeneous mass. Characteristic prenatal diagnostic features include identifying systemic arterial blood supply or arteries from the aorta to the fetal lung lesion via color Doppler signals.

Since bronchopulmonary sequestration lacks normal bronchial communication, extralobar sequestration often shows no obvious symptoms and is usually discovered during prenatal or postnatal checkups. In contrast, intralobar sequestration disrupts the normal arrangement of bronchioles in the lung lobe, potentially creating abnormal "dead spaces." This often manifests as recurrent lung infections or even abscess formation within the sequestration, leading to symptoms such as fever, cough, and pneumonia.

In rare cases, abnormal blood supply—due to significant arteriovenous shunting (slow pulmonary arterial blood flow into pulmonary veins) within the sequestration or massive hemoptysis causing blood loss or intrathoracic hematoma—may result in heart failure (high-output heart failure).

Can bronchopulmonary sequestration cause miscarriage or affect the fetus?

For lung lesions detected during pregnancy, their impact on the fetus primarily depends on their size. Most newborns with bronchopulmonary sequestration are asymptomatic or develop symptoms after birth, allowing for postnatal surgical intervention.

Excessively large lesions can cause significant mass effects, such as mediastinal shift leading to obstructed venous return and cardiac compression. This may ultimately present as fetal hydrops, severely impairing development or causing miscarriage. In such cases, prenatal treatments—including early delivery with immediate postnatal resection or fetal surgery—are required.

Does bronchopulmonary sequestration affect infant development?

Asymptomatic bronchopulmonary sequestration does not initially impact infant development, which is why the age of discovery varies widely, with cases reported from infancy to adulthood.

However, bronchopulmonary sequestration with respiratory symptoms can impair lung function due to recurrent infections or significant mass effects, thereby affecting infant development.

CAUSES

What causes bronchopulmonary sequestration?

The etiology of pulmonary sequestration is not fully understood, and there are no clear teratogenic factors.

Current pathological studies suggest that bronchopulmonary sequestration arises from the formation of accessory lung buds at the caudal end of normal lung buds. The primitive bronchial tree begins as a ventral diverticulum of the foregut at 3 weeks, bifurcates into left and right lung buds around day 26, and forms the definitive lobes of the lung between the 5th and 8th weeks of gestation. Therefore, bronchopulmonary sequestration likely occurs during early pregnancy.

DIAGNOSIS

How is bronchopulmonary sequestration diagnosed?

It can be detected during fetal ultrasound examination, as early as 16 weeks of gestation, presenting as a well-defined triangular echogenic mass in the lower thorax or upper renal region of the abdomen. Accurate prenatal diagnosis requires visualization of its feeding artery, where Doppler ultrasound may be helpful. Prenatal magnetic resonance imaging (MRI) can further clarify the diagnosis.

For a child with recurrent respiratory infections and lung shadows on chest X-ray, contrast-enhanced computed tomography (CT) can help confirm the diagnosis.

During diagnosis and treatment, imaging findings may have certain limitations. Definitive diagnosis often requires surgical intervention and pathological examination. Possible differential diagnoses include pulmonary adenomatoid malformation, bronchogenic cyst, enteric duplication cyst, and mediastinal tumors.

What tests are needed for bronchopulmonary sequestration?

Prenatal ultrasound is recommended as the primary diagnostic method for evaluating suspected thoracic masses in the fetal stage.

Bronchopulmonary sequestration typically appears as a hyperechoic chest mass on ultrasound. Doppler ultrasound can detect abnormal arteries and draining veins, confirming the diagnosis. If evaluation is challenging, magnetic resonance imaging (MRI) is recommended for further assessment.

After birth, if bronchopulmonary sequestration is suspected, computed tomography (CT) can reveal parenchymal abnormalities associated with the condition. The typical appearance is a complex mass with or without cystic changes. Sometimes, it may present as a large fluid-filled or air-filled microcyst or a large cavitary lesion with air-fluid levels. More importantly, CT can identify abnormal arterial supply and venous drainage.

TREATMENT

Which department should I visit for bronchopulmonary sequestration?

For suspected bronchopulmonary sequestration, thorough prenatal evaluation by obstetricians and ultrasonographers is required, followed by a comprehensive consultation with a pediatric cardiothoracic surgery specialist.

Can bronchopulmonary sequestration heal on its own?

Bronchopulmonary sequestration is a congenital lung malformation that does not resolve spontaneously. However, some children may remain asymptomatic, and the condition may go undetected during prenatal exams, potentially remaining unnoticed until adulthood.

How is bronchopulmonary sequestration treated?

For asymptomatic children with confirmed bronchopulmonary sequestration, no medication can improve the condition. Typically, evaluation by a cardiothoracic surgery specialist at 6–12 months of age is recommended, followed by elective surgical treatment. In rare cases where prenatal evaluation indicates significant fetal impact, postnatal assessment of respiratory compression symptoms may be necessary, with emergency surgery required to relieve mass effects if needed.

For patients diagnosed due to respiratory infection symptoms, antibiotic treatment is advised first, followed by surgical timing evaluation after infection control.

What surgical methods are available for bronchopulmonary sequestration?

Surgical options include traditional lateral thoracotomy with intercostal resection and minimally invasive resection (thoracoscopic bronchopulmonary sequestration removal).

With advancements in medical technology and equipment, minimally invasive resection is now feasible for eligible cases, offering faster recovery, less trauma, and smaller scars. However, it requires specialized perioperative surgical and anesthetic techniques and equipment. Traditional surgery, while mature and less technically demanding, involves greater trauma and more noticeable scarring.

What are the common risks of surgical treatment for bronchopulmonary sequestration?

In major pediatric medical centers, this surgery is technically mature but remains high-risk in pediatric thoracic surgery. Common risks include trauma to surrounding tissues, pleural effusion, pneumothorax, and bleeding.

Systematic reviews suggest that asymptomatic children with pulmonary airway malformations benefit more from early surgical intervention. Delaying surgery until symptoms appear increases the likelihood of complications.

Does surgery for bronchopulmonary sequestration affect lung function?

Outcomes vary depending on surgical approach and age. With advancements in enhanced recovery after surgery, most children can be discharged within a week postoperatively, gradually resuming light exercise, a healthy diet, and regular routines.

Postoperative studies indicate that for intralobar sequestration resection performed before age 1, early effects may include reduced exercise tolerance and susceptibility to wheezing. However, with rehabilitation, long-term lung function can normalize. Extralobar resection shows no significant impact.

However, older surgical age and preoperative recurrent lung infections may lead to long-term declines in lung function.

DIET & LIFESTYLE

What should patients with bronchopulmonary sequestration pay attention to in diet and daily life?

For symptomatic children, timely medical evaluation of surgical options and timing is necessary. While awaiting surgery, avoid crowded, enclosed spaces to reduce the risk of respiratory infections and maintain a balanced diet. During postoperative recovery, engage in gradual, moderate exercise to improve lung function.

Does bronchopulmonary sequestration require follow-up examinations? How?

For children who have not yet undergone surgery, surgical timing and plans should be assessed at 6–12 months of age.

For children who have recovered well after surgery, a chest X-ray and pulmonary function test are recommended one year post-operation to assess lung condition. During long-term follow-up, chest X-rays and pulmonary function tests should be performed every 2–3 years.

Is bronchopulmonary sequestration hereditary? Will it affect future fertility?

No, it is not hereditary and does not affect fertility.

Bronchopulmonary sequestration is not a chromosomal disorder and therefore has no direct hereditary tendency. There is currently no evidence suggesting a genetic risk or any impact on fertility.

Can children with bronchopulmonary sequestration travel by plane, train, or high-speed rail?

Yes.

Children with bronchopulmonary sequestration can safely use public transportation such as planes, trains, or high-speed rail. Since the abnormal tissue is not connected to the normal bronchial tree, the risk of emergencies due to air pressure changes is not increased.

Is the treatment for bronchopulmonary sequestration expensive?

Treatment costs for bronchopulmonary sequestration are relatively high.

Bronchopulmonary sequestration is a type of congenital lung malformation, and some national financial aid is available for treating congenital structural anomalies. For details, consult the local hospital's medical insurance department.

PREVENTION

Can Bronchopulmonary Sequestration Be Prevented?

No.

Since there is no clear cause of the disease, there are no preventive measures for bronchopulmonary sequestration. However, following national guidelines for prenatal care and adopting scientific approaches to pregnancy can promote healthy births.

Does Bronchopulmonary Sequestration Recur?

Generally, it does not recur.

Most cases of bronchopulmonary sequestration can be completely removed without recurrence. However, in rare cases of intralobar sequestration where segmental resection is performed, it may be difficult to fully expose the lesion boundaries during surgery, potentially leaving residual tissue and leading to recurrence.