Variants of the scimitar syndrome

Introduction The scimitar syndrome comprises hypoplastic right pulmonary artery and lung, anomalous right pulmonary venous drainage to the inferior caval vein, aortopulmonary collateral(s) to the right lung, and bronchial anomalies. Aim The aim of this study was to describe the morphological and clinical spectrum of variants from the classical scimitar syndrome in a single institution over 22 years.

In total, 10 patients were recognised. The most consistent feature was an aortopulmonary collateral to the affected lung (90%), but there was considerable variation in the site and course of pulmonary venous drainage. This was normal in 3 (one with meandering course), anomalous right to superior caval vein in 1, to the superior caval vein and inferior caval vein in 2, and to the superior caval vein and the left atrium in 1; one patient had a right pulmonary (scimitar) vein occluded at the insertion into the inferior caval vein but connected to the right upper pulmonary vein via a fistula. There were two left-sided variants, one with anomalous left drainage to the coronary sinus and a second to the innominate vein. Among all, three patients had an antenatal diagnosis and seven presented between 11 and 312 months of age; 90% of the patients were symptomatic at first assessment. All the patients underwent cardiac catheterisation; collateral embolisation was performed in 50% of the patients. Surgical repair of the anomalous vein was carried out in two patients, one patient had a right pneumonectomy, and one patient was lost to follow-up. There was no mortality reported in the remainder of patients during the study period.

The heterogeneity of this small series confirms the consistent occurrence of an anomalous arterial supply to the affected lung but considerable variation in pulmonary venous drainage.