Congenital lung malformation: evaluation of prenatal and postnatal radiological findings.

BACKGROUND AND OBJECTIVE: This study evaluated the accuracy of prenatal MRI and postnatal CT imaging in the identification of congenital cystic adenomatoid malformation and bronchopulmonary sequestration by comparison with histological analysis. METHODS: Over a 3-year period, 15 patients with lung malformations diagnosed prenatally by ultrasound were referred for prenatal MRI, and all were investigated postnatally by chest CT. All asymptomatic newborns with unresolved lesions underwent elective surgery by thoracoscopy. All surgical specimens were analysed histologically. RESULTS: Among the 15 patients with an abnormality diagnosed by ultrasound, prenatal MRI findings differed from the final histological diagnosis with respect to extent (n = 3), type of lesion (n = 1) and aberrant vessel identification (n = 4). Postnatal chest CT failed to visualize the aberrant vessel in one patient. Complete regression of the lesion was noted in two patients with bronchopulmonary sequestration, and in one patient with congenital cystic adenomatoid malformation and was confirmed by CT. Elective thoracoscopic lobectomy of the affected lobe was performed for 12 patients. Two conversions to thoracotomy were required. All operated patients had an uneventful hospital course. CONCLUSIONS: Prenatal MRI is less accurate than postnatal CT scan, which remains the most reliable diagnostic modality to specify the location and extent and kind of lesions.

Aerosol deposition in neonatal ventilation.

Lung deposition of inhaled drugs in ventilated neonates has been studied in models of questionable relevance. With conventional nebulizers, pulmonary deposition has been limited to 1% of the total dose. The objective of this study was to assess lung delivery of aerosols in a model of neonatal ventilation using a conventional and novel electronic micropump nebulizer. Aerosol deposition studies with 99mTc diethylenetriamine pentaacetate (99mTc-DTPA) were performed in four macaques (2.6 kg) that were ventilated through a 3.0-mm endotracheal tube (with neonatal settings (peak inspiratory pressure 12-14 mbar, positive end-expiratory pressure 2 mbar, I/E ratio 1/2, respiratory rate 40/min), comparing a jet-nebulizer MistyNeb (3-mL charge, 4.8 microm), an electronic micropump nebulizer operating continuously [Aeroneb Professional Nebulizer (APN-C); 0.5-mL charge, 4.6 microm], and another synchronized with inspiration [Aeroneb Professional Nebulizer Synchronized (APN-S); 0.5-mL charge, 2.8 microm]. The amount of radioactivity deposited into lungs and connections and remaining in the nebulizer was measured by a gamma counter. Despite similar amounts of 99mTc-DTPA in the respiratory circuit with all nebulizers, both APN-S and APN-C delivered more drug to the lungs than MistyNeb (14.0, 12.6, and 0.5% in terms of percentage of nebulizer charge, respectively; p = 0.006). Duration of delivery was shorter with APN-C than with the two other nebulizers (2 versus 6 and 10 min for the APN-S and the MistyNeb, respectively; p < 0.001). Electronic micropump nebulizers are more efficient to administer aerosols in an animal model of ventilated neonates. Availability of Aerogen's electronic micropump nebulizers offers new opportunities to study clinical efficacy and risks of aerosol therapy in ventilated neonates.