Pulmonary Vein Stenosis

Pulmonary vein stenosis (PVS) is a rare condition in which the veins that carry blood from the lungs back to the heart are narrowed. This is a different condition than pulmonary valve stenosis and peripheral pulmonary stenosis.

Sometimes, PVS can occur as a complication of another heart or lung problem. While the exact cause of pulmonary vein stenosis is not known, current research suggests that abnormal or turbulent blood flow that alters a force called shear stress is one of the primary causes of pulmonary vein stenosis. There may be multiple different reasons for abnormal shear stress on the walls of the pulmonary veins.

Some children will need many interventions — including cardiac catheterization or surgery — to restore blood flow to the heart, as pulmonary vein stenosis tends to recur and can worsen over time.

Pulmonary vein stenosis can occur in several forms. Generally, pulmonary vein stenosis is grouped into the following categories:

Intraluminal pulmonary vein stenosis

This is a common type of pulmonary vein stenosis that is caused by an abnormal thickening of the walls in the pulmonary veins. (The term “intraluminal” means “within the lumen,” the central opening that allows blood to flow into the vein.)

The narrowing is believed to be linked to an abnormal overgrowth of connective tissue cells — the cells that help our bodies repair and close wounds — within the pulmonary veins.

Isolated pulmonary vein stenosis

Isolated pulmonary vein stenosis occurs when a baby has no other defects or problems in the heart or lungs at birth, but then has sudden, often rapidly progressing, symptoms in early infancy. Babies with this type of pulmonary vein stenosis can seem healthy for several weeks before suddenly having difficulty breathing and low oxygen levels.

Pulmonary vein stenosis as a secondary complication

Some children develop pulmonary vein stenosis as a secondary complication of another heart or lung problem. Often, their pulmonary vein stenosis is discovered after they have already been diagnosed with a condition like complex congenital heart disease or chronic lung disease.

Symptoms of pulmonary vein stenosis can occur very suddenly, especially in infants, or may progress gradually over time. In both cases, symptoms may include:

• Shortness of breath
• Rapid heartbeat
• Rapid, shallow breathing
• Fatigue
• Poor appetite
• Pale or “washed-out” skin hue
• Blue-tinged appearance, called cyanosis, of the skin, lips, or nail beds

Pulmonary vein stenosis is typically diagnosed with one or more of the following procedures:

• An echocardiogram, which uses sound waves to make a moving picture of the heart’s structure and function
• Cardiac catheterization, which uses a small, flexible tube threaded up to the heart to give very detailed information about the structures within the heart and lungs
• A computed tomography (CT) scan, a non-invasive procedure using X-ray equipment and powerful computers to produce detailed, cross-sectional images of a particular area of the body (such as the chest cavity)
• A pulmonary blood flow scan, or lung scan, which uses an injectable dye and a special camera to track the flow of blood through your child’s lungs

Your child's exact treatment plan will be determined by:

• What other heart or lung problems they may have
• Symptoms and overall health
• Number of pulmonary veins affected
• Extent of narrowing within the pulmonary veins
• Your family's preferences

In many cases, multiple interventions will be necessary over time, since the narrowing process can recur and become more pronounced even after catheterization or surgery. Children with pulmonary vein stenosis typically need one or more of the following procedures to combat the harmful narrowing process and restore adequate flow of oxygen-rich blood to the heart.

Cardiac catheterization

Cardiac catheterization uses a thin tube, called a catheter, which is threaded from a vein or artery into the heart. The catheter is used to open narrowed passageways in the pulmonary veins and create new passageways if needed. There are two types of catheterization commonly used to treat PVS.

• Balloon dilation: The most common interventional catheterization procedure used here at Boston Children's is balloon dilation. With the child under sedation, a small, flexible catheter is inserted into a blood vessel, most often in the groin. Using tiny, highly precise cameras and tools, clinicians guide the catheter up into the inside of the heart and then into the affected areas of the pulmonary veins. A deflated balloon at the tip of the catheter is inflated once the tube is in place, and this balloon stretches the constricted area open, reversing the problematic narrowing.
• Balloon dilation and stent placement: The effects of balloon dilation can be amplified for some children with pulmonary vein stenosis by using a combination of balloon dilation and the placement of a balloon-expandable stent — a small, stainless steel tube. The stent is attached to the balloon dilation catheter as it is fed into the narrowed parts of the pulmonary veins.

The protective covering is removed when the catheter is in place, and the balloon is then inflated. The balloon affixes the stent within the pulmonary vein, stretching the narrowed area and propping it open.

Children may need several interventional catheterizations over time as they grow, since the narrowing process tends to recur and can become progressively worse.

Open-heart surgery

Some children may need open-heart surgery to widen the narrowed areas of the pulmonary veins to allow blood to flow from the lungs to the heart.

Drug therapy

The PVS team may recommend targeted drug therapy for your child in an effort to slow or stop the pulmonary vein stenosis from recurring. Our team will help decide on an individualized plan in which your child may receive medical therapy for a minimum of six months, depending on the severity of PVS, and would require monthly blood work.

Lung transplant

In some cases, the damage caused by PVS cannot be managed with cardiac catheterization or surgery. These children may need a lung transplant to replace the lungs and pulmonary veins.

Boston Children’s Hospital has a dedicated Pulmonary Vein Stenosis Program whose expert clinicians have decades of experience treating children, adolescents, and adults with this condition.

Our specialized training in pediatric cardiology means that we understand the particular challenges, circumstances, and intricacies of working with young people with pulmonary vein stenosis. In addition to our medical expertise, we provide patient-centered care that always recognizes your child as an individual — and we offer resources to meet the needs of your entire family.

Over the past two decades, our team has been at the forefront of research to learn more about this rare condition and discover treatment options for patients. In addition to developing new techniques to treat PVS in the catheterization lab and operating room, our team has started using drug therapy to treat intraluminal pulmonary vein stenosis.