Pulmonary sequestration: What the radiologist should know

Pulmonary sequestration consists of a nonfunctioning mass of lung tissue, either sharing the pleural envelope of the normal lung (intralobar) or with its own pleura (extralobar), lacking normal communication with the tracheobronchial tree and receiving its arterial supply by one or more systemic vessels. It is the second most common congenital lung anomaly according to pediatric case series, but its real prevalence is likely to be underestimated, and imaging plays a key role in the diagnosis and treatment management of the condition and its potential complications. We will give a brief overview of the pathophysiology, clinical presentation and imaging findings of intra- and extralobar pulmonary sequestration, with particular reference to multidetector computed tomography as part of a powerful and streamlined diagnostic approach.

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.

Percutaneous laser ablation under ultrasound guidance for fetal hyperechogenic microcystic lung lesions with hydrops: a single center cohort and a literature review

OBJECTIVE

To evaluate the perinatal outcomes in hydropic fetuses with congenital microcystic pulmonary lesions that underwent percutaneous, invasive, laser therapy.

METHOD

This retrospective study reviews the literature and our experience between 2004 and 2010. Characteristics of the cystic lung lesions, liquor volume (presence of polyhydramnios or not), localization of ablation (vascular vs interstitial) and gestational age at which the procedure was performed were related to outcome (survival).

RESULTS

In total, 16 fetuses with congenital lung lesions underwent 'invasive' percutaneous laser ablation, seven performed in our center and nine published cases. Survival rate was higher in fetuses with a subsequent postnatal diagnosis of bronchopulmonary sequestration (87.5%) compared with congenital adenomatoid malformation (28.6%; p = 0.04). The technique of vascular ablation was more successful (100%) than interstitial ablation (25.0%, p < 0.01).

CONCLUSION

Percutaneous vascular laser ablation seems to be effective for bronchopulmonary sequestration in hydropic fetuses. Outcomes were worst following interstitial ablation for microcystic congenital adenomatoid with hydrops.

[Congenital lung malformations--when to operate?]

Advances in antenatal imaging over the past 10 years have completely changed diagnosis and management of congenital lung disease, especially for congenital cystic adenomatoid malformations and sequestrations that are the two lesions most commonly detected. If early surgical excision is required for symptomatic cases, management of asymptomatic malformations is still discussed. The natural evolution and consequences of later complications of congenital lung malformations need to be compared with the benefits of elective resection and surgical morbidity. Complete regression of sequestrations or clinical and morphological improvement in congenital lobar emphysema pleads for clinical watching. On the other hand, resection is advocated for cystic malformations, because of an increased risk of acute respiratory distress, later infections and the possibility of malignant transformation. Even though the proportion of asymptomatic patients that go on to develop symptoms is hard to evaluate, an argument for elective surgery is a better outcome than emergency surgery. Further studies and long term follow-up are still needed to understand the natural history of congenital lung malformations precisely and help to define the optimal way in which to manage them.