Scimitar Syndrome (Anomalous Pulmonary Venous Return (APVR))

The scimitar syndrome was first described in 1836 by Cooper et al. (Cooper 1836). Nevertheless, Halasz et al. introduced the term scimitar to describe the pulmonary vein anomalies of this syndrome in 1956 (Halasz et al. 1956). Eventually, the syndrome was named, characterized, and linked to the scimitar sign in 1960 by Neill et al. (Neill 1960). It is called scimitar (a Turkish sword) due to the appearance of a half crescent in radiological studies caused by pulmonary vein anomaly, with the tip pointing toward the junction of the diaphragm and right heart border. However, this appearance, also known as the Scimitar sign, does not appear in every patient (Gudjonsson and Brown 2006). Scimitar syndrome is characterized by partial or total anomalous venous drainage of the right lung into the inferior vena cava (IVC), right lung hypoplasia, right pulmonary artery malformations, and left-to-right shunt (Vida and Guariento 2020). The incidence is estimated to be 1 to 3 per 100,000 live births (Wang et al. 2022).