Fetal Intraventricular Hemorrhage in Open Neural Tube Defects: Prenatal Imaging Evaluation and Perinatal Outcomes

BACKGROUND AND PURPOSE

Fetal imaging is crucial in the evaluation of open neural tube defects. The identification of intraventricular hemorrhage prenatally has unclear clinical implications. We aimed to explore fetal imaging findings in open neural tube defects and evaluate associations between intraventricular hemorrhage with prenatal and postnatal hindbrain herniation, postnatal intraventricular hemorrhage, and ventricular shunt placement.

MATERIALS AND METHODS

After institutional review board approval, open neural tube defect cases evaluated by prenatal sonography between January 1, 2013 and April 24, 2018 were enrolled (n = 504). The presence of intraventricular hemorrhage and gray matter heterotopia by both prenatal sonography and MR imaging studies was used for classification. Cases of intraventricular hemorrhage had intraventricular hemorrhage without gray matter heterotopia (n = 33) and controls had neither intraventricular hemorrhage nor gray matter heterotopia (n = 229). A total of 135 subjects with findings of gray matter heterotopia were excluded. Outcomes were compared with regression analyses.

RESULTS

Prenatal and postnatal hindbrain herniation and postnatal intraventricular hemorrhage were more frequent in cases of prenatal intraventricular hemorrhage compared with controls (97% versus 79%, 50% versus 25%, and 63% versus 12%, respectively). Increased third ventricular diameter, specifically >1 mm, predicted hindbrain herniation (OR = 3.7 [95% CI, 1.5-11]) independent of lateral ventricular size and prenatal intraventricular hemorrhage. Fetal closure (n = 86) was independently protective against postnatal hindbrain herniation (OR = 0.04 [95% CI, 0.01-0.15]) and postnatal intraventricular hemorrhage (OR = 0.2 [95% CI, 0.02-0.98]). Prenatal intraventricular hemorrhage was not associated with ventricular shunt placement.

CONCLUSIONS

Intraventricular hemorrhage is relatively common in the prenatal evaluation of open neural tube defects. Hindbrain herniation is more common in cases of intraventricular hemorrhage, but in association with increased third ventricular size. Fetal closure reverses hindbrain herniation and decreases the rate of intraventricular hemorrhage postnatally, regardless of the presence of prenatal intraventricular hemorrhage.

Two's Company: Multiple Thoracic Lesions on Prenatal US and MRI

BACKGROUND

Congenital pulmonary airway malformations (CPAM), bronchopulmonary sequestrations (BPS), and CPAM-BPS hybrid lesions are most commonly solitary; however, >1 lung congenital lung lesion may occur.

OBJECTIVES

To assess the frequency of multiple congenital thoracic anomalies at a high-volume referral center; determine prenatal ultrasound (US) and magnetic resonance imaging (MRI) features of these multifocal congenital lung lesions that may allow prenatal detection; and determine the most common distribution or site of origin.

METHODS

Database searches were performed from August 2008 to May 2019 for prenatally evaluated cases that had a final postnatal surgical diagnosis of >1 congenital lung lesion or a lung lesion associated with foregut duplication cyst (FDC). Lesion location, size, echotexture, and signal characteristics were assessed on prenatal imaging and correlated with postnatal computed tomographic angiography and surgical pathology. -Results: Of 539 neonates that underwent surgery for a thoracic lesion, 35 (6.5%) had >1 thoracic abnormality. Multiple discrete lung lesions were present in 19 cases, and a lung lesion associated with an FDC was present in 16. Multifocal lung lesions were bilateral in 3 cases; unilateral, multilobar in 12; and, unilobar multisegmental in 4. Median total CPAM volume/head circumference ratio for multifocal lung lesions on US was 0.66 (range, 0.16-1.80). Prenatal recognition of multifocal lung lesions occurred in 7/19 cases (36.8%). Lesion combinations were CPAM-CPAM in 10 cases, CPAM-BPS in 5, CPAM-hybrid in 2, hybrid-hybrid in 1, and hybrid-BPS in 1. Of 5 unilateral, multifocal lung lesions, multifocality was prenatally established through identification of a band of normal intervening lung or intrinsic differences in lesion imaging features.

CONCLUSIONS

Although less common, multiple thoracic abnormalities can be detected prenatally. Of multifocal lung lesions, the most common combination was CPAM-CPAM, with a unilateral, multilobar distribution. Prenatal recognition is important for pregnancy counseling and postnatal surgical management.

Myelomeningocele sac associated with worse lower-extremity neurological sequelae: evidence for prenatal neural stretch injury?

OBJECTIVE

To determine whether the presence of a myelomeningocele (MMC) sac and sac size correlate with compromised lower-extremity function in fetuses with open spinal dysraphism.

METHODS

A radiology database search was performed to identify cases of MMC and myeloschisis (MS) diagnosed prenatally in a single center from 2013 to 2017. All cases were evaluated between 18 and 25 weeks. Ultrasound reports were reviewed for talipes and impaired lower-extremity motion. In MMC cases, sac volume was calculated from ultrasound measurements. Magnetic resonance imaging reports were reviewed for hindbrain herniation. The association of presence of a MMC sac and sac size with talipes and impaired lower-extremity motion was assessed. Post-hoc analysis of data from the multicenter Management of Myelomeningocele Study (MOMS) randomized controlled trial was performed to confirm the study findings.

RESULTS

In total, 283 MMC and 121 MS cases were identified. MMC was associated with a lower incidence of hindbrain herniation than was MS (80.9% vs 100%; P < 0.001). Compared with MS cases, MMC cases with hindbrain herniation had a higher rate of talipes (28.4% vs 16.5%, P = 0.02) and of talipes or lower-extremity impairment (34.9% vs 19.0%, P = 0.002). Although there was a higher rate of impaired lower-extremity motion alone in MMC cases with hindbrain herniation than in MS cases, the difference was not statistically significant (6.6% vs 2.5%; P = 0.13). Among MMC cases with hindbrain herniation, mean sac volume was higher in those associated with talipes compared with those without talipes (4.7 ± 4.2 vs 3.0 ± 2.6 mL; P = 0.002). Review of the MOMS data demonstrated similar findings; cases with a sac on baseline imaging had a higher incidence of talipes than did those without a sac (28.2% vs 7.5%; P = 0.007).

CONCLUSIONS

In fetuses with open spinal dysraphism, the presence of a MMC sac was associated with fetal talipes, and this effect was correlated with sac size. The presence of a larger sac in fetuses with open spinal dysraphism may result in additional injury through mechanical stretching of the nerves, suggesting another acquired mechanism of injury to the exposed spinal tissue. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Secondary Imaging Findings Aid in Prenatal Diagnosis and Characterization of Congenital Diaphragmatic Hernia: Role of an Abnormal Orientation of Vascular Structures and Gallbladder Position

OBJECTIVES

To determine whether an abnormal orientation of the abdominal or hepatic vasculature and an abnormal gallbladder position on prenatal ultrasound (US) imaging are associated with intrathoracic liver herniation and postnatal outcomes in cases of congenital diaphragmatic hernia (CDH).

METHODS

Children who underwent prenatal US examinations and postnatal CDH repair at our institution were eligible. Prenatal US images were reviewed, and the orientation of the superior mesenteric artery (SMA) and hepatic veins as well as gallbladder position were recorded. Findings were correlated with prenatal US measurements (lung-to-head ratio and calculated observed-to-expected lung-to-head ratio) and postnatal outcomes, including intrathoracic liver herniation, an extracorporeal membrane oxygenation (ECMO) requirement, and mortality.

RESULTS

A total of 175 patients met inclusion criteria. The SMA was shown in 168 cases and had a cephalad orientation in 95.4% (161 of 168), which was not associated with outcome measures and represented bowel herniation. A cephalad orientation of the hepatic veins was identified in 52.6% (90 of 171) and was associated with intrathoracic liver herniation, an ECMO requirement, and mortality (P < .01). In right-sided CDH, the gallbladder was intrathoracic in 91.3% (21 of 23). In left-sided CDH, an abnormal gallbladder position was seen in 51.3% (76/152) and was associated with intrathoracic liver herniation, an ECMO requirement, mortality, and lower lung-to-head ratio and observed-to-expected lung-to-head ratio values. When combined, abnormal hepatic vein and gallbladder positions showed good sensitivity and specificity in predicting intrathoracic liver herniation (area under the curve, 0.93).

CONCLUSIONS

Abnormal SMA, hepatic vein, and gallbladder positions can be used to improve prenatal characterization of CDH. Accurate depiction of these structures on prenatal US images may aid in patient counseling and postnatal management.

Congenital diaphragmatic hernia sacs: prenatal imaging and associated postnatal outcomes

BACKGROUND

The presence of a hernia sac in congenital diaphragmatic hernia (CDH) has been reported to be associated with higher lung volumes and better postnatal outcomes.

OBJECTIVE

To compare prenatal imaging (ultrasound and MRI) prognostic measurements and postnatal outcomes of CDH with and without hernia sac.

MATERIALS AND METHODS

We performed database searches from January 2008 to March 2017 for surgically proven cases of CDH with and without hernia sac. All children had a detailed ultrasound (US) examination and most had an MRI examination. We reviewed the medical records of children enrolled in our Pulmonary Hypoplasia Program.

RESULTS

Of 200 cases of unilateral CDH, 46 (23%) had hernia sacs. Cases of CDH with hernia sac had a higher mean lung-to-head ratio (LHR; 1.61 vs. 1.17; P<0.01), a higher mean observed/expected LHR (0.49 vs. 0.37; P<0.01), and on MRI a higher mean observed/expected total lung volume (0.53 vs. 0.41; P<0.01). Based on a smooth interface between lung and herniated contents, hernia sac or eventration was prospectively questioned by US and MRI in 45.7% and 38.6% of cases, respectively. Postnatally, hernia sac is associated with shorter median periods of admission to the neonatal intensive care unit (45.0 days vs. 61.5 days, P=0.03); mechanical ventilation (15.5 days vs. 23.5 days, P=0.04); extracorporeal membrane oxygenation (251 h vs. 434 h, P=0.04); decreased rates of patch repair (39.0% vs. 69.2%, P<0.01); and pulmonary hypertension (56.1% vs. 75.4%, P=0.03).

CONCLUSION

Hernia sac is associated with statistically higher prenatal prognostic measurements and improved postnatal outcomes. Recognition of a sharp interface between lung and herniated contents may allow for improved prenatal diagnosis; however, delivery and management should still occur at experienced quaternary neonatal centers.

Congenital Lobar Overinflation: A Rare Enigmatic Lung Lesion on Prenatal Ultrasound and Magnetic Resonance Imaging

OBJECTIVES

To report the ultrasound (US) features in prenatal cases of suspected congenital pulmonary airway malformation or unspecified lung lesions with a final surgical pathologic diagnosis of congenital lobar overinflation (CLO).

METHODS

Institutional Review Board-approved radiology and clinical database searches from 2001 to 2017 were performed for prenatally diagnosed lung lesions with a final diagnosis of CLO. All patients had detailed US examinations in addition to magnetic resonance imaging (MRI). Size, echotexture, and vascularity were assessed with US, and the signal and vascularity were assessed with MRI. Follow-up prenatal US scans, postnatal imaging, and postnatal outcomes were reviewed.

RESULTS

The study population consisted of 12 patients. The median gestational age was 23.3 weeks. The median congenital pulmonary airway malformation volume-to-head circumference ratio was 0.66. Lesion locations were 6 in the lower lobes (4 right and 2 left), 5 in the upper lobes (3 left and 2 right), and 1 in the right middle lobe. The texture was homogeneously echogenic relative to the normal lung in 100% with no visualized macrocysts. Hypervascularity by color Doppler US was observed in 5 cases (41.7%). A T2 hyperintense lung lesion was identified by MRI in 12 of 12 cases (100%), with elongated vessels identified in 11 of 12 cases (91.7%). All 12 cases had pathologically proven CLO.

CONCLUSIONS

Congenital lobar overinflation should be considered in cases of prenatal echogenic lung lesions without macrocysts or classic findings of bronchial atresia. Hypervascularity may be an important imaging feature of a subset of CLO. Most cases become less conspicuous, decrease in size without overt hydrops, and are asymptomatic postnatally.

Going With the Flow: An Aid in Detecting and Differentiating Bronchopulmonary Sequestrations and Hybrid Lesions

OBJECTIVES

To assess the ability of prenatal ultrasound (US) in identifying systemic feeding arteries in bronchopulmonary sequestrations and hybrid lesions and report the ability of US in classifying bronchopulmonary sequestrations as intralobar or extralobar.

METHODS

Institutional Review Board-approved radiology and clinical database searches from 2008 to 2015 were performed for prenatal lung lesions with final diagnoses of bronchopulmonary sequestrations or hybrid lesions. All patients had detailed US examinations, and most patients had ultrafast magnetic resonance imaging (MRI). Lesion location, size, and identification of systemic feeding arteries and draining veins were assessed with US.

RESULTS

The study consisted of 102 bronchopulmonary sequestrations and 86 hybrid lesions. The median maternal age was 30 years. The median gestational age was 22 weeks 5 days. Of bronchopulmonary sequestrations, 66 had surgical pathologic confirmation, and 100 had postnatal imaging. Bronchopulmonary sequestration locations were intrathoracic (n = 77), intra-abdominal (n = 19), and transdiaphragmatic (n = 6). Of hybrid lesions, 84 had surgical pathologic confirmation, and 83 had postnatal imaging. Hybrid lesion locations were intrathoracic (n = 84) and transdiaphragmatic (n = 2). Ultrasound correctly identified systemic feeding arteries in 86 of 102 bronchopulmonary sequestrations and 79 of 86 hybrid lesions. Of patients who underwent MRI, systemic feeding arteries were reported in 62 of 92 bronchopulmonary sequestrations and 56 of 81 hybrid lesions. Ultrasound identified more systemic feeding arteries than MRI in both bronchopulmonary sequestrations and hybrid lesions (P < .01). Magnetic resonance imaging identified systemic feeding arteries that US did not in only 2 cases. In cases in which both systemic feeding arteries and draining veins were identified, US could correctly predict intrathoracic lesions as intralobar or extralobar in 44 of 49 bronchopulmonary sequestrations and 68 of 73 hybrid lesions.

CONCLUSIONS

Ultrasound is most accurate for systemic feeding artery detection in bronchopulmonary sequestrations and hybrid lesions and can also type the lesions as intralobar or extralobar when draining veins are evaluated.

Fetal Lymphatic Malformations: More Variable Than We Think?

Lymphatic malformations are benign lesions that result from abnormal development of the lymphatic and venous systems. These lesions may be detected during routine prenatal ultrasound screening, and typically demonstrate imaging findings of a multiseptate cystic lesion lacking solid components, vascularity, and calcifications. We report 73 cases of prenatally detected lymphatic malformations and describe greater variability in their prenatal sonographic appearance than previously reported, including purely cystic lesions and mixed cystic and solid lesions with calcifications. Appreciation of this increased variability is important in providing accurate prenatal diagnosis, counseling, and management.