Non-immune hydrops fetalis and bilateral pulmonary hypoplasia in a newborn infant with extralobar pulmonary sequestration

Systemic Venous Drainage Is Associated with an Unfavorable Prenatal Behavior in Fetal Bronchopulmonary Sequestration

OBJECTIVE

This study aimed to determine the significance of the venous drainage pattern of bronchopulmonary sequestration (BPS) in the prenatal course.

METHODS

The venous drainage pattern of fetuses with BPS was determined with high-definition flow and confirmed by postnatal three-dimensional computed tomography angiography scan or autopsy. The volume of BPS lesions during gestation was recorded by the three-dimensional ultrasonographic Virtual Organ Computer-Aided Analysis software. The relationship between venous drainage pattern and prenatal characteristics was determined.

RESULTS

Seventy-one fetuses were enrolled: 35 with systemic venous drainage (SVD) and 36 with pulmonary venous drainage (PVD). The volumes of BPS lesions significantly increased from the middle second trimester to the later second trimester in the SVD group. A marked decrease from the later second trimester to the third trimester was observed in the PVD group. The incidences of associated anomalies, hydrops, and polyhydramnios in the SVD group were 14.2, 23.3, and 33.3%, respectively, significantly higher than those in the PVD group (0, 0, and 5.6%, respectively).

CONCLUSIONS

Our data indicate that SVD is correlated with a higher risk of associated anomalies and an unfavorable prenatal course in fetal BPS. Identification of the venous drainage pattern is of clinical significance in predicting the prenatal behavior of fetal BPS.

Neonatal outcome after prenatal interventions for congenital lung lesions

Congenital lung lesions, mostly congenital cystic adenomatoid malformations (CCAMs) and bronchopulmonary sequestrations (BPSs), are uncommon disorders. Prenatal intervention in severely affected (hydropic) fetuses has drastically improved perinatal survival. Not much is known, however, on the short-term and long-term respiratory and neurodevelopmental outcome. Several small case series have been reported and suggest an increased incidence of neonatal morbidity, mainly associated with prematurity and respiratory failure at birth. Overall, neonatal mortality and morbidity after prenatal interventions for CCAM seems to be worse than for BPS. This review focuses on the neonatal outcome after prenatal intervention for congenital lung lesions and summarizes the results reported in the literature.

Prenatal interventions for fetal lung lesions

The widespread availability of high resolution ultrasound equipment and almost universal routine anatomy scanning in all pregnant women in the developed world has lead to increased detection of abnormalities in the fetal thorax. Already in the 1980s, large pleural effusions and significant macrocystic lesions in the fetus were easily detected on ultrasound. However, smaller lung tumours were often missed. Nowadays, fetal medicine centres receive many referrals for evaluation of fetal lung lesions, of which the most common are congenital cystic adenomatoid malformation and bronchopulmonary sequestration. Almost invariably, both the parents and the referring physicians experience anxiety after detection of large lung masses in the fetus. However, the vast majority of the currently detected fetal lung lesions have an excellent prognosis without the need for prenatal intervention. In the small group of fetuses in which the prognosis is poor, almost exclusively those with concomitant fetal hydrops and cardiac failure, several options for fetal therapy exist, often with a more than 50% survival rate. Indications, techniques, complications and outcomes of these interventions will be described in this review.

Prenatal diagnosis and outcome of echogenic fetal lung lesions

OBJECTIVE

To describe the antenatal findings and outcome of fetuses with echogenic lung lesions.

METHODS

This was a retrospective study of the prenatal sonographic features, antenatal management and outcome of 193 fetuses with an echogenic lung lesion diagnosed at 18-35 weeks of gestation. There were nine cases of congenital high airway obstruction syndrome (CHAOS), 170 cases of cystic adenomatoid malformation (CAM) and 14 cases of pulmonary sequestration (PS). A literature search was also carried out to compare our data with those of previous series.

RESULTS

The prognosis in our series of fetuses with CHAOS was invariably poor, but the literature describes a handful of survivors after delivery by Cesarean section and ex-utero intrapartum therapy (EXIT). Of the cases in our series with PS and no pleural effusions, more than 95% survived; in half of these cases the lesion resolved antenatally and in the other half sequestrectomy was carried out postnatally. In cases with PS and pleural effusions, successful treatment was provided by the placement of thoracoamniotic shunts or occlusion of the feeding blood vessel by ultrasound-guided laser coagulation or injection of sclerosants. In cases with CAM and no hydrops, there was more than 95% survival and in up to half of the cases there was sonographic evidence of spontaneous antenatal resolution of the hyperechogenic lesion, which was confirmed by postnatal imaging in about 60% of the cases. Of the cases with CAM with hydrops managed expectantly, more than 95% died before or after birth. Of the cases with macrocystic CAM with hydrops, two-thirds survived after placement of a thoracoamniotic shunt. In cases with microcystic CAM with hydrops, there is some evidence that open fetal surgery with lobectomy could improve survival but such treatment is highly invasive for the mother.

CONCLUSIONS

CHAOS is a severe abnormality, whereas CAM and PS are associated with a good prognosis. In a high proportion of fetuses with hyperechogenic lung lesion, there is spontaneous antenatal resolution and the underlying pathology may be transient bronchial obstruction.

Hydrops fetalis and pulmonary sequestration

The development of fetal hydrops in conjunction with intrathoracic pathology has been described, but rarely in association with pulmonary sequestration. The current report presents three cases of antenatally identified nonimmune hydrops fetalis, seen in association with pulmonary sequestrations. In one case, a left-sided chest mass also was defined. One infant was born by emergency cesarean section because of fetal distress at 34 weeks' gestation; the other two were delivered vaginally at 30 and 36 weeks. Two of the newborns were severely hydropic and required aggressive cardiorespiratory resuscitation that included bilateral chest tubes for massive pleural effusions. The third infant was stable at the time of birth, but thereafter respiratory distress developed, and intubation and ventilation became necessary. Two of the infants had a left-chest mass and the other had a right-sided mass, all identified by chest x-ray. Subsequent ultrasonography showed a chest mass and an identifiable systemic feeding artery in two of the patients. For the third, a specific diagnosis was not made before surgery. After resolution of hydrops, all three infants had successful removal of their intrathoracic pulmonary sequestrations. Two of these were found to be extralobar, and the other was an intralobar sequestration of the left lower lobe.

Morphology of pulmonary extralobar sequestration in neonatal death by hyaline membrane disease

We present an unusual case of extralobar pulmonary sequestration associated with hyaline membrane disease (HMD) that caused the death of a premature baby in the first day of life. The sequestered parenchyma was nourished by an aberrant aortic vessel. Notable was the presence of typical HMD in all the lung parenchyma perfused by the pulmonary artery; the sequestered lung tissue presented a dysplastic structure compatible with CCAM. A few similar cases have been found in the literature. In all of the reported cases there are morphologic aspects characteristic of HMD in the portions normally receiving blood from the pulmonary artery. These findings suggest the importance of the blood pulmonary circulation in the pathogenesis of HMD, whose exact causes are not fully known.