Prenatal Course and Postnatal Management of Peripheral Bronchial Atresia: Association with Congenital Cystic Adenomatoid Malformation of the Lung

Abstract

Objective: Peripheral bronchial atresia (PBA), a newly identified fetal lung lesion, is often asymptomatic and managed nonoperatively. However, recent studies suggest that bronchial atresia plays a role in the etiology of microcystic maldevelopment present in congenital cystic adenomatoid malformations (CCAM) which require resection to decrease the risk of infection, pneumothorax and malignant degeneration. The purpose of this study was to evaluate the prenatal radiographic and postnatal computed tomography (CT) scan/pathology findings with attention to the pathologic diagnosis of microcystic maldevelopment in infants with the presumptive diagnosis of PBA. Methods: A retrospective review of prenatal and postnatal records of patients diagnosed with fetal lung lesions was performed. Two groups of patients were identified: (1) patients diagnosed with PBA on postnatal CT scan (n = 16), and (2) patients with the pathologically confirmed diagnosis of PBA independent of postnatal CT findings (n = 23). Results: Prenatal ultrasound diagnosis of these lesions included CCAMs, hybrid lesions, bronchopulmonary sequestrations and bronchial atresia. Eleven of the 16 patients in group 1 with the postnatal radiologic diagnosis of PBA underwent surgical resection, 6 of which were found to have microcystic changes consistent with CCAM. Evaluation of the 23 patients in group 2 with pathologically confirmed PBA identified 65% that had evidence of microcystic maldevelopment consistent with the small cyst type of CCAM. Conclusion: Radiographically diagnosed PBA as well as pathologically confirmed PBA is frequently associated with microcystic changes consistent with the small cyst type of CCAM. Thus, operative management should be considered for PBA to decrease CCAM-associated risks.

Open Fetal Surgery for Central Bronchial Atresia

“…It can occur at different levels of the airway resulting in segmental, lobar or mainstem bronchial atresia. It has been suggested to play a role in the etiology of a spectrum of congenital lung abnormalities including CCAMs, bronchopulmonary sequestrations, and congenital lobar emphysema [11,14]. In the majority of cases, bronchial atresia occurs in the distal airways in which case there is a low likelihood of fetal hemodynamic compromise.…”

“…These infants are often asymptomatic at birth and previously have presented in late childhood or early adulthood after suffering recurrent pulmonary infections [15]. However, due to advances in prenatal imaging, patients with distal bronchial atresias, similar to patients with small lobar congenital pulmonary airway malformations (CPAMs), currently are frequently diagnosed prenatally and, if they remain asymptomatic, undergo elective pulmonary resection at 1 month of age due to the risk of infection [11,16]. In contrast, cases of mainstem or lobar bronchial atresia are associated with massive lung hyperplasia, mediastinal shift and contralateral lung hypoplasia with progression to non-immune fetal hydrops and fetal demise [17,18,19].…”

“…These findings were believed to be consistent with a mainstem or lobar bronchial atresia. Bronchial atresias are sometimes histologically associated with CCAM elements and thus the patient received a course of betamethasone in an attempt to mitigate the growth of the lesion and onset of fetal hydrops [3,4,11]. Frequent serial ultrasound examinations documented an enlargement of the mass (CVR of 1.6 to 3.64 from 21 to 24 weeks' gestation) despite a second course of betamethasone at 23 weeks' gestation.…”

Outcomes of Prenatally Diagnosed Lung Lesions in Multigestational Pregnancies

“…Congenital cystic lung lesions are space-occupying masses [4,5] and represent a spectrum of disease. Such lesions may be small and of minimal prenatal clinical significance or may enlarge to cause pathophysiologic derangement via rapid growth and mediastinal compression.…”

“…Although the management and outcomes of fetal chest lesions have been delineated [4,5,9,10,11,12,13], no study has specifically examined the outcomes of multigestational pregnancies complicated by a fetal chest mass. Both the effect of a fetal chest mass on the outcome of the normal twin or triplet and the effect of multiple gestation on the final outcome of the affected fetus are unknown.…”