Purpose or Case Report: The purpose of this study is to describe the MR and US prenatal imaging features and associated anomalies of unilateral pulmonary agenesis, as well as characterize the morbidity and mortality in postnatal life.
Methods & Materials: IRB approval was obtained. 8 prenatal cases of unilateral pulmonary agenesis were identified from January 2005 through October 2016. Gestational age at evaluation and delivery, gender, imaging appearance, associated anomalies seen prenatally and postnatally, surgical interventions and outcomes were reviewed.
Results: Eight cases were identified fulfilling criteria. All 8 underwent prenatal MRI and US. Of the 8 cases, 7 had postnatal follow up. There were 3 males, 5 females. Common reasons for referral included suspected situs anomalies (5/8) and suspected congenital diaphragmatic hernia (1/8).Only one referral suspected pulmonary agenesis. 7 of 8 lesions were right-sided. Prenatal findings included severe cardiomediastinal shift; MR was useful in confirming absent lung tissue and ipsilateral bronchus. Additional fetal anomalies in the VACTERL spectrum were identified prenatally and confirmed in all 7 cases with postnatal follow up. In 6/7, additional VACTERL anomalies were discovered postnatally. 5 of 8 had congenital heart defects including atrioventricular canal (1/8), bilateral SVC (1/8) left SVC (1/8), pulmonary vein stenosis (1/8) and ventricular septal defect (1/8). Single umbilical artery was present in 2. Additional intrinsic airway anomalies were discovered postnatally in 4: tracheobronchomalacia (2/8), severely narrowed contralateral bronchus (1/8), and complete tracheal rings (1/8). Spine anomalies were present in 5/8; renal and limb anomalies both present in 2/8. GI anomalies were present in 4/8: tracheoesophageal fistula (3/8), imperforate anus (1/8) and malrotation (1/8). Four died within 1 year of delivery. There were 3 survivors and 1 was lost to follow up.
Conclusions: Pulmonary agenesis is a rare diagnosis with significant morbidity and mortality. Fetal MRI and US play complementary roles in establishing the diagnosis. This entity should be considered in the spectrum of VACTERL and concurrent abnormalities should be carefully looked for to support appropriate counseling.