What is pulmonary vein stenosis?

Pulmonary vein stenosis is a rare and chronic condition that affects the blood vessels that deliver newly oxygenated blood from the lungs back into the heart. When any of these four veins are narrowed or blocked, the heart does not receive the oxygenated blood it needs, leading to serious health complications affecting the heart, lungs and other body organs.

Children with pulmonary vein stenosis require intervention – typically cardiac catheterization or heart surgery (and sometimes both) – to restore adequate blood flow to the heart. In some cases, repeated cardiac catheterizations are needed. Without careful monitoring and treatment as needed, symptoms of pulmonary vein stenosis will worsen. It can lead to pulmonary hypertension (high lung pressure), heart failure, and death.

Pulmonary vein stenosis is different than pulmonary stenosis, which affects the function of the pulmonary valve.

Cause of pulmonary vein stenosis

The exact cause of pulmonary vein stenosis (PVS) remains unknown. In some cases, the condition may be congenital (occurring from birth), in other cases, a child may develop PVS as a complication to another heart or lung issue, or after heart surgery. Patients can have stenosis (a partial blockage) or atresia (a full blockage) of one, multiple, or all pulmonary veins. PVS occurs as a result of the thickening of the interior walls of the pulmonary veins, blocking steady blood flow. The wall thickening is caused by an overgrowth of cells which typically promote wound healing and repair (myofibroblast-like cells).

Types of patients with pulmonary vein stenosis

There are three main types of patients who have pulmonary vein stenosis.

Primary or Isolated PVS often happens in infancy in a baby with no history of heart or lung defects at birth. Weeks after birth, these babies suddenly develop symptoms – such as low oxygen levels and difficulty breathing – that progress rapidly and can be life-threatening if not correctly identified and treated.

PVS associated with congenital heart disease can occur in patients who require surgical repair of a congenital heart defect. Patients who undergo surgical repair of veins that do not connect normally to the heart are at a higher risk of developing PVS.

PVS is associated with lung disease, particularly in patients born prematurely who develop chronic lung disease as a result of bronchopulmonary dysplasia.

Signs and symptoms of pulmonary vein stenosis

Symptoms of pulmonary vein stenosis can vary depending on the cause, type, and severity. In most cases – particularly among infants with more than one pulmonary vein affected – symptoms appear suddenly after birth, can cause significant damage, and have a high mortality rate. In less-severe cases – e.g., when only one or two pulmonary veins are partially blocked – the abnormal signs and symptoms of pulmonary vein stenosis may appear more gradually.

Symptoms may include:

• Breathing differences (e.g., shortness of breath, shallow breathing, panting)
• Feeding intolerance
• Cardiac issues (e.g., rapid heartbeat, pulmonary hypertension, heart failure)
• Abnormally pale or blue-tinged skin
• Coughing up blood

About half of all patients with pulmonary vein stenosis will have an additional associated heart or lung condition.

Testing and diagnosis of pulmonary vein stenosis

Pulmonary vein stenosis may be suspected in infants and children with a combination of symptoms listed above. To determine the severity of the child’s condition and plan the best treatment, clinicians at Children’s Hospital of Philadelphia (CHOP) may order several diagnostic tests including:

• Pulse oximetry, which monitors the amount of oxygen in the blood
• A chest x-ray to look at the lungs
• Echocardiogram (sometimes called an "echo" or ultrasound), which uses sound waves to see the internal structure of the heart and its function
• Electrocardiogram (ECG), which measures the electrical activity in the heart
• A lung perfusion scan uses X-ray to quantify the amount of blood flow to each lung
• A computed tomography (CT) scan, which uses X-rays and computers to produce cross-sectional images of the chest
• Cardiac MRI, which creates a three-dimensional picture of the heart arteries and veins
• Cardiac catheterization, in which a thin, flexible tube (catheter) is inserted through a vein in the leg and into the heart to provide detailed information about the structure and function within the heart and lungs. During the catheterization, a small (2mm) ultrasound probe can be inserted in the pulmonary veins to look at the wall of the veins (i.e. intravascular ultrasound).

Treatment for pulmonary vein stenosis

CHOP has a dedicated Pulmonary Vein Stenosis Program that includes pediatric cardiac specialists and cardiac catheterization experts who work together to diagnose, treat, and monitor patients with this rare and often misunderstood condition.

Treatment for pulmonary vein stenosis will depend on several factors, including how many pulmonary veins are affected, the degree of blockage, severity of symptoms, and other factors, such as the patient’s age, other associated diagnoses, and overall health. At CHOP, we provide patient-centered care that focuses on your child and providing your family with the educational and support resources you need to best support your sick child.

Your child’s treatment will be determined based on:

• Their symptoms and overall health, including if they have other heart or lung problems
• The number of pulmonary veins affected
• The degree of narrowing within the pulmonary veins
• Your family’s preferences

At CHOP, pulmonary vein stenosis is treated with a combination of interventions, including cardiac catheterization procedures, drug therapy, and cardiac surgery. In most cases, children with pulmonary vein stenosis will require multiple interventions over time to combat vein narrowing, and worsening symptoms and to restore the flow of oxygen-rich blood to the heart.

Cardiac catheterization

Cardiac catheterization, may be used as a treatment in addition to a testing. During cardiac catheterization, an interventional cardiologist inserts a thin tube (catheter) into a vein in the child’s leg, and then guides it to the child’s heart. The catheter – with a balloon on the end of it – is briefly inflated to open the narrow vein, then deflated and withdrawn.

In some cases, a combination of balloon dilation and an expandable stent is used to open the narrowed part of the affected pulmonary vein and prop it open for blood to flow properly from the lungs to the heart. Multiple interventional cardiac catheterizations may be needed as the child grows and as narrowing or symptoms recur.

Surgery

When cardiac catheterization cannot adequately relieve the symptoms of pulmonary vein stenosis, open-heart surgery may be needed to relieve an obstruction or widen the narrowed areas of the pulmonary veins. The goal of surgery for PVS is to improve blood flow from the lungs to the heart.

Drug therapy

Medication or drug therapy may be recommended for your child to slow or halt the progression of pulmonary vein stenosis. Depending on the severity of your child’s condition, drug therapy may be recommended, typically for at least 12 months, with regular blood work and monitoring.

Transplant

In very rare cases when a child’s lungs have been significantly damaged by pulmonary vein stenosis and other treatments have not helped enough, a lung transplant to replace the lungs and pulmonary veins may be recommended.

Follow up care for pulmonary vein stenosis

Children with pulmonary vein stenosis will require lifelong follow up care and repeated treatment as needed. It’s important for individuals with PVS to continue regular checkups with a cardiologist throughout their lives. Some individuals will require medication and may need to limit their physical activity. At Children’s Hospital of Philadelphia, our pediatric cardiologists follow patients until they are young adults and coordinate care with primary care physicians. Adult patients may be then transitioned to the Philadelphia Adult Congenital Heart Center, a joint program run by CHOP and the University of Pennsylvania.

Outlook for patients with pulmonary vein stenosis

A generation ago, PVS was fatal for most children with the condition. Today, the outlook for these children is improving. Advanced screening, innovative interventions, and cutting-edge treatments have made survival possible for about 70% of children diagnosed with pulmonary vein stenosis.

Early diagnosis is crucial to getting infants and young children with PVS the interventions and treatments they need to continue growing and developing.