Mainstem bronchial atresia: a lethal anomaly amenable to fetal surgical treatment.

PURPOSE: The purpose of this study was to review the unique imaging characteristics, prenatal course, and outcomes for fetuses with mainstem bronchial atresia (MBA).

METHODS: The records of all patients referred for a fetal lung malformation from 2001 to 2012 and the medical literature were reviewed to identify cases of MBA.

RESULTS: Of 129 fetuses evaluated, 3 were diagnosed prenatally with right-sided MBA. The first had a CCAM-volume ratio (CVR) of 9, hydrops, mirror syndrome, and preterm delivery of a nonviable fetus. The second (CVR 2.6) had ascites, preterm delivery at 34-weeks, and neonatal demise. The third fetus (CVR 5.7) presented with hydrops at 21-weeks, prompting fetal pneumonectomy. Postoperatively, hydrops resolved, and the contralateral lung grew dramatically, but preterm delivery occurred 3 weeks later. Ventilation could not be sustained, and the infant died. Four similar cases of MBA were in the literature, all right-sided. Two fetuses with hydrops delivered at 25-weeks and died immediately. One pregnancy was terminated. One fetus underwent pneumonectomy at 24-weeks but died intraoperatively.

CONCLUSION: MBA is a rare and lethal lesion that must be distinguished from other right-sided lung masses. Fetal pneumonectomy can be performed with resolution of hydrops and compensatory contralateral lung growth, but remains limited by complications of preterm birth.