Critical Pulmonary Stenosis.

Critical pulmonary stenosis is a severe narrowing of the right ventricular outflow, leading to severe obstruction of blood flow from the right ventricle to the pulmonary artery often requiring the need for ductal patency to provide adequate pulmonary blood flow following birth. Diagnosis relies on echocardiography, with percutaneous balloon valvuloplasty as the preferred treatment and surgery for select cases. Long-term follow-up is essential due to risks of restenosis, pulmonary regurgitation, and reintervention, while advances in fetal therapy and valve replacement offer promising future improvements in outcomes.