Pulmonary vascular malformations.

Pulmonary vascular malformations have historically been diagnosed in a wide range of age groups, but the extensive use of prenatal imaging studies has resulted in the majority of lesions being diagnosed in utero. Among this group of lesions, bronchopulmonary sequestrations (BPS), hybrid lesions with both congenital cystic adenomatoid malformation (CCAM) and BPS, aberrant systemic vascular anastomoses, and pulmonary arteriovenous malformations (PAVM), are the most common. The biologic behavior of these lesions and the subsequent therapy is, in large part, determined by the age of the patient at diagnosis. In the fetus, large BPS or hybrid lesions can result in fetal hydrops and in utero fetal demise. In the perinatal period, pulmonary hypoplasia from the mass effect or air trapping within the cystic component of hybrid lesions can result in life-threatening respiratory distress. In the postnatal period, communication of the lesion with the aero-digestive system can result in recurrent pneumonia. Alternatively, increased pulmonary blood flow from the systemic arterial supply can result in hemorrhage, hemoptysis, or high output cardiac failure. In addition, there have been several reports of malignant degeneration. Finally, the broad spectrum encompassed by these lesions makes classification and subsequent communication of the lesions confusing and difficult. This paper will review the components of these lesions, their associated anomalies, the diagnosis and natural history, and finally, current concepts in the management of pulmonary vascular malformations.