Treatment Options for Pulmonary Arterial Stenosis

Supportive and Symptomatic Management

Supportive care typically involves oxygen therapy and measures to improve ventilation. Patients with comorbidities such as pulmonary hypertension or chronic pulmonary heart disease may benefit from vasodilators and diuretics to manage symptoms and improve quality of life.

Pharmacological Therapy

Medications play a key role in managing pulmonary arterial hypertension associated with pulmonary stenosis. These drugs aim to reduce pulmonary pressure, improve hemodynamics, and enhance functional capacity.

Endothelin Receptor Antagonists

• Bosentan: This drug is used to treat pulmonary hypertension caused by conditions such as vasculitis, sarcoidosis, or congenital heart defects with left-to-right shunt. It is particularly effective for patients classified as WHO functional class II–IV, helping to improve exercise capacity and delay clinical worsening. Bosentan is administered orally. However, it has teratogenic potential, so it is contraindicated in pregnancy. Women who are breastfeeding should consider discontinuing lactation. Common side effects include headache, edema, elevated liver enzymes, and anemia.
• Macitentan: Another endothelin receptor antagonist, macitentan is indicated for pulmonary hypertension secondary to congenital heart disease or connective tissue disorders. It helps alleviate symptoms and improve long-term outcomes. Like bosentan, it is contraindicated during pregnancy due to potential fetal harm. Side effects may include elevated liver enzymes, peripheral edema, fluid retention, reduced hemoglobin levels, and, in rare cases, pulmonary edema associated with pulmonary veno-occlusive disease or impaired spermatogenesis.

Rho-Kinase Inhibitors

Fasudil: This agent is used in cases of severe pulmonary arterial stenosis associated with congenital heart disease. It effectively lowers pulmonary artery pressure in the short term without compromising systemic circulation. Fasudil is generally well tolerated, although adverse effects may include intracranial or gastrointestinal bleeding, hypotension, facial flushing, elevated liver enzymes, and gastrointestinal symptoms such as nausea and vomiting.

Surgical Interventions

For more severe or complex cases, surgical correction may be necessary to relieve obstruction and restore normal blood flow through the pulmonary arteries.

Pulmonary Valvotomy

This procedure involves establishing cardiopulmonary bypass and performing a longitudinal incision approximately 0.5 cm above the pulmonary valve annulus while the heart is still beating. The fused valve commissures and any adhesions between the valve leaflets and arterial wall are carefully dissected. A vertical incision is made through the fused commissures down to the annulus, sometimes extended into a "T" shape to widen the valve opening. The pulmonary artery incision is then closed, and bypass is discontinued.

Right Ventricular Outflow Tract Patch Augmentation

In cases of severe pulmonary stenosis with underdeveloped valve annulus and significant right ventricular outflow tract obstruction, simple valvotomy may be insufficient. A more extensive approach includes extending the incision into the right ventricular outflow tract, removing hypertrophied myocardial tissue, and using a pericardial patch to enlarge the outflow tract across the valve. Care must be taken during dissection to avoid injury to the posterior pulmonary artery wall or coronary arteries.

Percutaneous Balloon Valvuloplasty

This minimally invasive procedure involves placing a balloon catheter under fluoroscopic guidance. The balloon is inflated at the site of the stenosis to widen the valve orifice. While effective for many patients, the procedure can be technically challenging in cases of extremely small valve openings.

Interventional Therapies

Interventional techniques have become increasingly popular due to their low invasiveness, reduced risk profile, and effectiveness in reducing the severity of pulmonary stenosis. These approaches are suitable for patients with isolated congenital stenosis, complex congenital heart disease involving pulmonary arteries, or acquired forms of pulmonary arterial narrowing.

Patients may be considered candidates for percutaneous pulmonary intervention if they meet the following criteria:

• Three-dimensional CT angiography confirms moderate to severe peripheral pulmonary artery stenosis.
• There is evidence of reduced lung perfusion corresponding to the stenotic area, along with moderate to severe pulmonary hypertension or right heart dysfunction.
• No contraindications to interventional procedures are present.

However, interventional therapy is not suitable for patients with unstable clinical conditions, contrast allergies, or those unable to tolerate the procedure. Each treatment plan should be tailored to the individual patient's anatomy, symptoms, and overall health status.