Pulmonary sequestration

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Pulmonary sequestration
Classification and external resources
Pulmonary-sequestration-001.jpg
ICD-10Q33.2
ICD-9748.5
DiseasesDB32120
eMedicineped/2628 radio/585
MeSHD001998
 
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Pulmonary sequestration
Classification and external resources
Pulmonary-sequestration-001.jpg
ICD-10Q33.2
ICD-9748.5
DiseasesDB32120
eMedicineped/2628 radio/585
MeSHD001998

A pulmonary sequestration (also known as a bronchopulmonary sequestration or cystic lung lesion), is a medical condition wherein a piece of tissue that ultimately develops into lung tissue is not attached to the pulmonary arterial blood supply, as is the case in normally developing lung. As a result, this sequestered tissue is not connected to the normal bronchial airway architecture, and as a result, fails to function in, and contribute to, respiration of the organism.

This condition is usually diagnosed in children and is generally thought to be congenital in nature. More and more, these lesions are diagnosed in utero by prenatal ultrasound.

Symptoms[edit]

Symptoms can vary greatly, but they include a persistent dry cough.

Diagnosis[edit]

Bronchopulmonary sequestration (BPS) is a rare congenital malformation of the lower respiratory tract.

It consists of a nonfunctioning mass of normal lung tissue that lacks normal communication with the tracheobronchial tree, and that receives its arterial blood supply from the systemic circulation.

BPS is estimated to comprise 0.15 to 6.4 percent of all congenital pulmonary malformations, making it an extremely rare disorder.

Sequestrations are classified anatomically.

Intralobar sequestration (ILS) in which the lesion is located within a normal lobe and lacks its own visceral pleura.

Extralobar sequestration (ELS) in which the mass is located outside the normal lung and has its own visceral pleura

The blood supply of 75% of pulmonary sequestrations is derived from the thoracic or abdominal aorta.

The remaining 25% of sequestrations receive their blood flow from the subclavian, intercostal, pulmonary, pericardiophrenic, innominate, internal mammary, celiac, splenic, or renal arteries.

Intralobar sequestration[edit]

Extralobar sequestration[edit]

Imaging[edit]

Chest radiograph[edit]

Ultrasound[edit]

CT[edit]

Chest CT showing pulmonary sequestration

MRI[edit]

Complications[edit]

Failure to have a pulmonary sequestration removed can leads to a number of complications. These include:

Treatment[edit]

Usually the sequestration is removed after birth via surgery. In most cases this surgery is safe and effective; the child will grow up to have normal lung function.

In a few instances, fetuses with sequestrations develop problematic fluid collections in the chest cavity. In these situations a Harrison catheter shunt can be used to drain the chest fluid into the amniotic fluid.

In rare instances where the fetus has a very large lesion, resuscitation after delivery can be dangerous. In these situations a specialized delivery for management of the airway compression can be planned called the EXIT procedure, or a fetal laser ablation procedure can be performed. During this minimally invasive fetal intervention, a small needle is inserted into the sequestration, and a laser fiber is targeted at the abnormal blood vessel going to the sequestration.  The goal of the operation is to use laser energy to stop the blood flow to the sequestration, causing it to stop growing. Ideally, after the surgery, the sequestration steals less blood flow from the fetus, and the heart and lungs start growing more normally as the sequestration shrinks in size and the pleural effusion goes away.  

The treatment for this is a segmentectomy via a thoracotomy.

Pulmonary sequestrations usually get their blood supply from the thoracic aorta. (intrapulmonary sequestration drains via pulmonary veins, extra pulmonary sequestration drains to the IVC)

Sources[edit]

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