Partial Anomalous Pulmonary Venous Return

  • Etiology: congenital
  • Imaging:
    — Most common form is anomalous drainage of right superior pulmonary vein into superior vena cava which is often associated with superior sinus venosus atrial septal defect
    — Another form is Scimitar syndrome / hypogenetic lung syndrome which is right sided with pulmonary veins (forming scimitar vein) draining typically to inferior vena cava or inferior vena cava / right atrium junction with hypoplasia of right lung and right pulmonary artery, in 66% Scimitar vein drains entire right lung, in 33% Scimitar vein drains only part of right lung (usually right upper lobe), 20% of Scimitar veins are obstructed
    — Findings that constitute Scimitar syndrome – right lung hypoplasia / right pulmonary artery hypoplasia / bronchial + lobation anomalies, horseshoe / crossover lung + diaphragm abnormalities, aberrant systemic arterial supply +/- sequestration
  • Clinical: causes left to right shunt

Cases of Partial Anomalous Pulmonary Venous Return

CXR and angiogram of partial anomalous pulmonary venous return
CXR AP (above) shows a hypoplastic right lung, AP arterial (left) and venous (right) phases of a pulmonary artery angiogram show a right pulmonary (scimitar) vein draining into the inferior vena cava.