Spectrum of pulmonary sequestration: association with anomalous pulmonary venous drainage in infants.

Pulmonary sequestration is a spectrum of related lesions, each of which may be absent or present: (1) bronchial sequestration of pulmonary parenchyma; (2) arterial supply from systemic circulation; (3) anomalous pulmonary venous drainage to the right atrium; (4) communications between bronchus and esophagus; (5) defects of diaphragm; (6) gross lung anomalies, such as horseshoe lungs or hypoplasia. Any combination of these primary lesions can occur in an individual patient. Diagnosis should be directed towards each component of the spectrum. Of special importance is the venous connection, as anomalous pulmonary venous drainage can involve not only the sequestered segment but the entire ipsilateral lung, making surgical therapy far more complex. Treatment of choice is surgical resection, associated, if needed, with rerouting of the pulmonary venous return. Classification of sequestration of the lung as intra- and extralobar is of secondary importance: these 2 groups do not represent lesions of different embryological significance.