Definition & Overview
Pulmonary artery stenosis is the narrowing of the pulmonary artery, a major artery that brings deoxygenated blood from the heart to the lungs. When this artery is blocked, the blood flow is disrupted and the blood gets less oxygen. This is the reason why patients with the condition have bluish skin colour. They also experience fatigue, breathlessness, and chest pain. Unless they seek treatment, the condition can cause serious health problems that can eventually lead to death.
The repair of a narrowed pulmonary artery using different techniques aims to widen the arterial wall to restore normal blood flow.
Who Should Undergo and Expected Results?
The methods used to treat pulmonary artery stenosis depend on the severity of the condition. Mild blockage can be treated using medications. However, if the narrowing is more than 50%, minimally invasive surgical procedures are considered. Typically, patients with this condition suffer from the following symptoms:
- Shortness of breath
- Rapid heart rate
- Heavy or rapid breathing
- Swelling in the abdomen, ankles, feet, and eyelids
To determine the best treatment for the patient, doctors perform various diagnostic procedures to properly assess the severity of the condition. These tests may include electrocardiography (ECG), chest x-ray, echocardiography (producing an echocardiogram), and/or cardiac MRI (magnetic resonance imaging).
How is the Procedure Performed?
The type of treatment for pulmonary artery stenosis depends on the severity of the condition. As mentioned above, mild stenosis can be treated with medications while severe cases may require a procedure called balloon valvuloplasty.
In a balloon valvuloplasty, a catheter is inserted in the vein located in the groin. The catheter is passed through the heart’s right ventricle and positioned to the area where the narrowing is identified. Once there, the catheter inflates the balloon, opening the artery in the process. As it increases in size, the narrowed area is stretched and widened. When the correct width is achieved, the balloon is deflated and the catheter is withdrawn.
In repairing pulmonary stenosis, a patch or a graft that is made of human tissue is used to widen the pulmonary valve in case it is very small. This is useful when the obstruction is not due to any blood clot but caused by thickened muscle tissue usually below the pulmonary valve.
A valve is a membranous structure with tissue flaps that open and close in response to pressure. Their primary function is to ensure that the flow of liquid only goes to a single direction. This means that any liquid that passes through it toward a certain direction will not flow back.
Normally, this procedure only applies to the pulmonary area. But in cases where doctors also identify a need to widen the blood vessels leading to the heart's right ventricle, a transannular patch (a patch across the pulmonary valve connective tissue) is used. This technique covers the wall of the right ventricle as well as treats or widens the pulmonary valve and the pulmonary artery.
Oftentimes, a procedure called cardiac catheterisation is performed to establish exactly the degree of blockage of the passageway. This is done by measuring the difference in blood pressure between the pulmonary artery and the right ventricle.
Possible Risks and Complications
The risks involved in the repair of pulmonary artery stenosis are small because it is minimally invasive. The procedure is also not complicated and usually lasts an hour or less depending on the severity of the condition.
Follow-up is required for most patients especially those who have a severe case of pulmonary artery stenosis. Regular testing will also need to be done to catch early symptoms of recurrence.
Some patients may need to take antibiotic maintenance to avoid any infection to the internal lining of the heart called bacterial endocarditis. This is done to prevent any infections during and after the procedure.
Physical activity can be resumed provided the surgeon has approved the level of activity the patient plans to take. The patient will have to stop any form of physical activity once symptoms, such as chest pain and breathlessness, manifest.
The procedure is also safe for pregnant women, as it does not cause any damage to the foetus. However, surgeons recommend that any signs of stenosis are treated and repaired before pregnancy to avoid any complications that might affect the baby in the womb during and after the procedure. This is because pregnant women with pulmonary artery stenosis have a high risk of developing atrial arrhythmias (abnormal heartbeat) and heart failure.
Despite the risk, balloon valvuloplasty can be performed on pregnant women with less risk to the foetus.
Warnes CA, Williams RG, Bashore TM, Child JS, Connolly HM, Dearani JA, et al. ACC/AHA 2008 Guidelines for the Management of Adults with Congenital Heart Disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to develop guidelines on the management of adults with congenital heart disease). Circulation. 2008 Dec 2. 118(23):e714-833.
Shaath G, Mutairi MA, Tamimi O, Alakhfash A, Abolfotouh M, Alhabshan F. Predictors of re-intervention in neonates with critical pulmonary stenosis or pulmonary atresia with intact ventricular septum. Catheter Cardiovasc Interv. 2011 Sep 27.