What is pulmonary artery stenosis?
Pulmonary artery stenosis is a narrowing (stenosis) that occurs in the pulmonary artery, a large artery that sends oxygen-poor blood into the lungs to be enriched with oxygen. The narrowing may occur in the main pulmonary artery and/or in the left or right pulmonary artery branches. This narrowing makes it difficult for blood to reach the lungs to pick up oxygen. Without enough oxygen, the heart and body cannot function as they should. In an effort to overcome the narrowing, the pressure in the right ventricle (the chamber that pumps blood into the pulmonary arteries) rises to levels that can be damaging to the heart muscle.
What are the symptoms of pulmonary artery stenosis?
If the narrowing in the artery is less than 50 percent, your child may not experience any symptoms. However, if the narrowing of the artery is more than 50 percent, your child may experience any of the following symptoms:
- shortness of breath
- heavy or rapid breathing
- rapid heart rate
- swelling in the feet, ankles, face, eyelids, and/or abdomen
What causes pulmonary artery stenosis?
Pulmonary artery stenosis is a congenital heart defect, meaning it is a defect that is inborn or exists at birth. Stated another way, the defect is an abnormality, not a disease. Pulmonary artery stenosis is often present in combination with other congenital heart defects, such as:
- Tetralogy of Fallot – a four-pronged defect consisting of: 1) a ventricular septal defect, 2) a narrowing at or just beneath the pulmonary valve, 3) a right ventricle that is more muscular than normal, 4) an aorta that lies directly over the ventricular septal defect
- Pulmonary atresia – absence of a pulmonary valve, preventing blood from flowing from the right ventricle into the pulmonary artery and onward to the lungs
- Truncus arteriosus – the formation of only one combined artery instead of the normal two outlets from the heart, the aorta and pulmonary artery
- Pulmonary valve stenosis – problems with the pulmonary valve (for example, development of less than three leaflets, leaflets that may be partially fused together, thick leaflets that do not open all the way) that make it more difficult for the valve leaflets to open and permit blood to flow from the right ventricle to the lungs
- Patent ductus arteriosus – an open passageway between the pulmonary artery and the aorta. Normally, this passageway closes on its own within a few hours of birth, but when it does not, surgery or an outpatient catheter-based procedure is needed to close the opening
Other causes of pulmonary artery stenosis can include: other syndromes that affect the heart (such as rubella syndrome [a group of heart and other health problems in an infant caused by rubella infection in the mother during pregnancy] and Williams syndrome [a group of abnormalities affecting the heart and other organs]) and surgical procedures used to correct other heart defects (for example, pulmonary artery banding - a purposeful narrowing of the artery to reduce blood flow to the lungs).
How is pulmonary artery stenosis diagnosed?
During a routine examination, your child’s doctor may hear abnormal heart sounds (a murmur) when listening to the heart. If abnormal sounds are identified, your doctor will order other tests that can include:
- An electrocardiogram (ECG or EKG) – a test that records the electrical changes that occur during a heartbeat; reveals abnormal heart rhythms (arrhythmias) and detects heart muscle stress
- Chest X-ray – a test to show the size and shape of the heart and lungs and pulmonary arteries
- An echocardiogram – a test that uses sound waves to create a moving picture of the heart’s internal structures
- Doppler ultrasound – a test that uses sound waves to measure blood flow; usually combined with echocardiogram to evaluate both the internal structure of the heart and blood flow across the heart’s valves and vessels
- Cardiac magnetic resonance imaging (MRI) – a test that uses three-dimensional imaging to reveal how blood flows through the heart and vessels and how the heart is working
- CT scan – an x-ray procedure that combines many x-ray images with the aid of a computer to generate cross-sectional views of the heart. Cardiac CT uses the advanced CT technology with intravenous (IV) contrast (dye) to visualize cardiac anatomy, coronary circulation, and great vessels
- Cardiac catheterization – a procedure that involves inserting a thin tube (a catheter) into a vein or artery and passing it into the heart to sample the level of oxygen, measure pressure changes, and make x-ray movies of the heart and its internal structures
- Pulmonary angiography – a dye-enhanced x-ray of the pulmonary arteries and veins of the heart
- Perfusion scan – a test in which the patient is injected with a small amount of a radioactive material. A special machine shows how well blood is flowing through each of the two lungs.
- Additional tests may be ordered as necessary
How is pulmonary artery stenosis treated?
If your child is diagnosed with pulmonary artery stenosis, your pediatrician or primary care doctor will recommend that you meet with a congenital heart specialist (a doctor who has the training and equipment to determine your child’s heart problem and order the necessary special tests, medical care, heart surgery, and follow-up checkups). The best treatment approach will depend on your child’s symptoms as well as other characteristics of the stenosis. Mild to moderate narrowing in one or more pulmonary artery branches usually does not require treatment, but severe cases do require some form of therapy. Available treatments include:
This treatment method consists of moving a balloon dilation catheter into the narrowed area of the artery. The balloon is carefully inflated – first under low pressure and then under higher pressure – until the narrowed area is widened. The balloon is then deflated and removed. Although the narrowing is improved in a majority of patients following balloon dilation, overtime the artery can again become narrow in as many as 15% to 20% of cases, requiring further ballooning. Different types of balloons are currently being developed that will likely lead to better and longer-lasting results.
Balloon dilation and stent placement
In an effort to improve on the results of balloon dilation, a search for a more effective treatment was begun and led to the development of the stainless steel balloon-expandable stent. Stent placement is accomplished by positioning the stent across the narrowed segment of the artery. The stent is mounted on a balloon angioplasty catheter and covered with a sheath as it is moved into position. The sheath then is withdrawn off the stent-balloon angioplasty assembly and the balloon is inflated to its recommended pressure, expanding the stent and anchoring it in place.
The Cutting Balloon™
This procedure is similar to standard balloon dilation but the balloon has been specially designed with small blades running up and down its length. When the balloon is inflated, the blades are activated and they cut through the narrowed area, making the vessel easier to dilate and resulting in a larger opening. Cutting balloons are available in different sizes.
The Cutting Balloon Image with permission, from Boston Scientific Corporation
Various methods of surgical repair of pulmonary artery stenosis are used, the choice of which depends on the characteristics of the stenosis and the surrounding vessels and other structures.
How to find a doctor if you have adult congenital heart disease
Doctors vary in quality due to differences in training and experience; hospitals differ in the number of services available. The more complex your medical problem, the greater these differences in quality become and the more they matter.
Clearly, the doctor and hospital that you choose for complex, specialized medical care will have a direct impact on how well you do. To help you make this choice, read more about our Sydell and Arnold Miller Family Heart & Vascular Institute outcomes. See: About Us to learn more about the Miller Family Heart & Vascular Institute at Cleveland Clinic.
The Center for Adult Congenital Heart Disease in the Sydell and Arnold Miller Family Heart & Vascular Institute is a specialized center involving a multi-disciplinary group of specialists, including cardiologists, cardiac surgeons and nurses from Cardiovascular Medicine, Pediatric Cardiology, Pediatric and Congenital Heart Surgery, Cardiothoracic Surgery, Diagnostic Radiology, Pulmonary, Allergy and Critical Care Medicine, and Transplantation Center, who provide a comprehensive approach to diagnosing and treating adult congenital heart disease.