Prenatal diagnosis of lobar bronchial atresia

Characterization of the Hyperintense Bronchus Sign as a Fetal MRI Marker of Airway Obstruction

Background Fetal MRI-based differential diagnosis of congenital lung malformations is difficult because of the paucity of well-described imaging markers. Purpose To characterize the hyperintense bronchus sign (HBS) in in vivo fetal MRI of congenital lung malformation cases. Materials and Methods In this retrospective two-center study, fetal MRI scans obtained in fetuses with congenital lung malformations at US (January 2002 to September 2018) were reviewed for the HBS, a tubular or branching hyperintense structure within a lung lesion on T2-weighted images. The frequency of the HBS and respective gestational ages in weeks and days were analyzed. Areas under the curve (AUCs), 95% CIs, and P values of the HBS regarding airway obstruction, as found in histopathologic and postnatal CT findings as the reference standards, were calculated for different gestational ages. Results A total of 177 fetuses with congenital lung malformations (95 male fetuses) and 248 fetal MRI scans obtained at a median gestational age of 25.6 weeks (interquartile range, 8.9 weeks) were included. The HBS was found in 79% (53 of 67) of fetuses with bronchial atresia, 71% (39 of 55) with bronchopulmonary sequestration (BPS), 43% (three of seven) with hybrid lesion, 15% (six of 40) with congenital cystic adenomatoid malformation, and 13% (one of eight) with bronchogenic cyst at a median gestational age of 24.9 weeks (interquartile range, 9.7 weeks). HBS on MRI scans at any gestational age had an AUC of 0.76 (95% CI: 0.70, 0.83; P = .04) for the presence of isolated or BPS-associated airway obstruction at histopathologic analysis and postnatal CT. The AUC of HBS on fetal MRI scans obtained until gestational age of 26 weeks (AUC, 0.83; 95% CI: 0.75, 0.91; P < .001) was significantly higher (P = .045) than that for fetal MRI scans obtained after gestational age 26 weeks (AUC, 0.69; 95% CI: 0.57, 0.80; P = .004). Conclusion The hyperintense bronchus sign is a frequently detectable feature at fetal MRI and is associated with airway obstruction particularly before gestational age 26 weeks. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Dubinsky in this issue.

Congenital Lung Malformations: Unresolved Issues and Unanswered Questions

Advances in prenatal and postnatal diagnosis, perioperative management, and postoperative care have dramatically increased the number of scientific reports on congenital thoracic malformations (CTM). Nearly all CTM are detected prior to birth, generally by antenatal ultrasound. After delivery, most infants do well and remain asymptomatic for a long time. However, complications may occur beyond infancy, including in adolescence and adulthood. Prenatal diagnosis is sometimes missed and detection may occur later, either by chance or because of unexplained recurrent or persistent respiratory symptoms or signs, with difficult implications for family counseling and substantial delay in surgical planning. Although landmark studies have been published, postnatal management of asymptomatic children is still controversial and needs a resolution. Our aim is to provide a focused overview on a number of unresolved issues arising from the lack of an evidence-based consensus on the management of patients with CTM. We summarized findings from current literature, with a particular emphasis on the vigorous controversies on the type and timing of diagnostic procedures, treatments and the still obscure relationship between CTM and malignancies, a matter of great concern for both families and physicians. We also present an algorithm for the assessment and follow-up of CTM detected either in the antenatal or postnatal period. A standardized approach across Europe, based on a multidisciplinary team, is urgently needed for achieving an evidence-based management protocol for CTM.

Prenatal and postnatal management of congenital bronchial atresia (CBA): single tertiary center report

OBJECTIVE

To summarize our diagnosis and management experience of congenital bronchial atresia (CBA).

METHODS

A retrospective review was conducted, clinical data were collected of all patients with CBA.

RESULTS

Among the nine patients (5 males and 4 females), six cases with right side and three cases with left cases, including one patient with mainstem bronchial atresia (MBA), two cases with lobar bronchial atresia (LBA), six cases with segmental bronchial atresia (SBA). Eight were diagnosed as congenital cystic adenomatoid malformation (CCAM) type III by ultrasound (US) in prenatal. The MBA patient was diagnosed by computed tomography (CT) and bronchofibroscopy, only two patients by pathological findings and the other six patients by CT. Five cases were accompanied by CCAM, one case with bronchopulmonary sequestration (BPS), two cases with emphysema. Eight cases except MBA were underwent thoracoscopic surgery treatment and had favorable prognosis. Two cases with LBA merged with complication of pectus excavatum after surgery. One case with MBA had no surgery and died in the 13 days old.

CONCLUSIONS

CBA is an easily misdiagnosed disease from pathologic conditions, definitive diagnosis of this condition depends on combination CT or clinical pathologic diagnosis. Thoracoscopic resection is a safe and feasible treatment of CBA in experienced hands.

Fetal bronchoscopy as a useful procedure in a case with prenatal diagnosis of congenital microcystic adenomatoid malformation

Massive microcystic congenital cystic adenomatoid malformation (CCAM) and bronchial atresia are associated with a high perinatal mortality secondary to lung hypoplasia and cardiac dysfunction, and fetal intervention should be considered to improve prognosis. Therapeutic options include open fetal surgery with pulmonary resection, fetal sclerotherapy and fetoscopy. We present a case with a severely enlarged left lung without ultrasound signs of dilated airways compatible with the diagnosis of microcystic CCAM, hydrops and severe contralateral lung hypoplasia that was treated successfully at 30 weeks of gestation by fetal bronchoscopy, through which bronchial atresia was identified at the end of the left mainstem bronchi and permeabilized by laser ablation. After fetal surgery, weekly follow-up showed a progressive decrease in the affected lung size and an increase in the contralateral hypoplastic lung size, demonstrating normal dimensions of both lungs at 34 weeks of gestation, reversal of the mediastinal shift, and complete disappearance of hydrops. A healthy neonate was delivered uneventfully at term with no need for respiratory support, and the boy is now doing well at 15 months of age. This report demonstrates that in cases with prenatal diagnosis of large microcystic CCAM, fetal bronchoscopy can be used to refine the diagnosis of bronchial atresia and as a therapeutic tool with good outcome.

Fetal bronchoscopy: its successful use in a case of extralobar pulmonary sequestration

OBJECTIVE

To report the performance of fetal bronchoscopy in a case of pulmonary sequestration.

MATERIALS AND METHODS

A 24 year-old female, Gravida 2, Para 1, was referred at 27.5 weeks with a large fetal left lung mass with marked right mediastinal shift and no visible normal left lung. Differential diagnosis included possible bronchial atresia.

RESULTS

The patient underwent fetal laryngoscopy and fetal bronchoscopy at 31.5 weeks. The right lung and a portion of the left lung expanded during surgery as a result of bronchial lavage. Bronchial atresia or bronchogenic cyst were not found. Pregnancy continued uneventfully, with continuous growth of the right lung and a small amount of left lung. The patient delivered vaginally at term. The baby underwent thoracoscopic resection of a pulmonary sequestration at 10.5 months of age and did well.

CONCLUSION

Fetal bronchoscopy is feasible. The procedure may prove useful in the differential diagnosis and in the potential treatment of different fetal lung lesions, as well as aid in the understanding of the role of bronchial obstruction as a common pathophysiologic mechanism for different fetal lung masses. Risks and benefits of fetal bronchoscopy warrant further experience.