Longitudinal observation of antenatally detected congenital lung malformations (CLM): natural history, clinical outcome and long-term follow-up.

OBJECTIVE: The objective of the study is to present longitudinal observations in antenatally detected congenital lung malformations (CLM), particularly pulmonary sequestration (PS) and cystic adenomatoid malformation (CAM).

METHODS: Fetuses found to have a CLM on prenatal ultrasound (US) were included in this study and followed up until delivery. In all newborns radiographs and computerized tomography (CT) studies of the thorax were performed. Surgical procedures included sequesterectomy, lobectomy, segmentectomy, and non-anatomic resection. Based on prenatal US findings, intrauterine course, postpartum chest radiographs and CT scans, as well as clinical signs and surgical findings patients were divided into six groups.

RESULTS: Over a period of 6 years, routine prenatal US revealed suggestion of CLM in a series of 35 consecutive fetuses. In six cases pregnancy was terminated or the fetuses suffered fetal demise. Another four fetuses became symptomatic in utero when sequential scanning revealed hydrops, hydrothorax, and enlargement of cysts or polyhydramnios. Three cases in this group received serial therapeutic amniocentesis and serial puncture of either the hydrothorax or intrapulmonary cysts. After postpartum treatment in the intensive care unit surgical procedures were performed uneventfully and confirmed the diagnosis of CAM, PS or hybrid type lesions. In 11 patients US findings were considered to demonstrate spontaneous resolution of the lesion, but disappearance without sequelae could be confirmed only in six infants. Five infants were shown to have persistent CLM on postpartum CT scans. These infants underwent resection of the lesion within the first year of life. In 11 fetuses CLM were continuously demonstrated during pregnancy with only slight changes in size and structure. Postpartum the infants were asymptomatic and were subjected to a systematic plan of diagnostic work-up and treatment. Surgery in these infants revealed a large number of hybrid type lesions (n=5). In three infants, the primary diagnosis of PS or CAM had to be corrected during the diagnostic and therapeutic work-up.

CONCLUSION: CLM are diagnosed antenatally with an increasing frequency and are shown to be quite different from previously applied concepts. The expected clinical outcome is far better than thought to be possible.