ABSTRACT
Anatomy and pathophysiology Stenotic lesions of the pulmonary arterial tree have been estimated to occur in 2-3% of patients with congenital heart disease.1 They are most common in conotruncal abnormalities such as tetralogy of Fallot and pulmonary atresia with VSD, but have been seen in almost all forms of congenital heart disease (CHD). Stenoses may be discrete or associated with long segment hypoplasia, and may be congenital or secondary to a surgical procedure. Post-surgical stenosis is most commonly due to scarring, especially at the site of a shunt, at the ends of a patch arterioplasty, or at the anastomotic sites of unifocalized vessels. Torsion, stretching, or compression of a pulmonary artery may also occur after procedures such as the arterial switch or Norwood operations. Rarely, stenosis can be caused by mediastinal inflammatory disorders (radiation or fibrosing mediastinitis) or extrinsic compression from neoplasm.
