Fetal MRI-Calculated Total Lung Volumes in the Prediction of Short-Term Outcome in Giant Omphalocele: Preliminary Findings

Abstract

Objective: To determine the value of fetal MRI-calculated total lung volumes (TLV) in the prediction of short-term outcome in patients with giant omphalocele (GO). Material and Methods: We reviewed all cases of GO undergoing fetal MRI after 21 weeks’ gestation and receiving postnatal care at our institution between 2003 and 2010. Observed/expected (O/E) TLV was calculated using age-matched TLV normograms [Radiology 2001;219:236–241]. Postnatal outcomes were stratified based on O/E TLV above or below 50% of expected. Results: Seventeen GO cases fulfilled the entry criteria. The mean age at fetal MRI evaluation was 25.8 ± 4.8 weeks’ gestation. The mean GO TLV (21.0 ± 13.2) was lower than age-matched population norms (p < 0.001), resulting in a mean O/E TLV of 52.3 ± 16.8%. The mean gestational age at delivery was 36.8 ± 1.6 weeks. Overall survival was 94%. Fourteen (88%) infants underwent staged reduction, and 2 underwent silver sulfadiazine treatment and delayed repair. Infants with ≤50% of predicted O/E TLV (n = 11, 65%) had lower Apgar scores at birth (p = 0.03), prolonged ventilatory support (p = 0.004), delayed oral intake (p = 0.03), and longer hospitalization (p = 0.03) compared to patients with ≥50% of expected O/E TLV. Two infants (both O/E TLV <50%) required tracheostomy placement. Conclusion: In the assessment of GO fetuses, MRI-based O/E TLV of <50% was predictive of increased postnatal morbidity.

High Prevalence of Pulmonary Hypertension Complicates the Care of Infants with Omphalocele

“…These infants have been shown to have a statistically longer length of stay and number of days on mechanical ventilation [6]. A higher incidence of respiratory failure, prolonged ventilatory support, abnormal pulmonary function testing in survivors, and need for tracheostomy have been described in many reports [5,9,14,23,24]. We suggest that this higher degree of pulmonary compromise in infants with liver-containing defects could be explained by the highly significant association found in our study between infants with liver-containing defects and the presence of PH.…”

“…Other explanations for respiratory failure have included pulmonary hypoplasia, abnormal lung and chest wall development, impaired antenatal lung growth, abnormal diaphragmatic mobility, and external compression of bronchi leading to lung collapse. Abnormalities in fetal breathing movements and amniotic fluid conditions in utero may also lead to small lung volumes, hypoplasia, or dysmorphic structure [9,10,14,23,25,27,28,29]. While lung volume measurements from imaging studies were not available in our cohort, it is likely that many infants requiring intubation at birth may have had varying degrees of this pulmonary hypoplasia.…”

Should We Measure Fetal Omphalocele Diameter for Prediction of Perinatal Outcome?

“…In fact, 3-dimensional ultrasound has shown that lung volume in fetuses with abdominal wall defects is smaller compared to normal fetuses [23]. In addition, an MRI study demonstrated that decreased lung volume in fetuses with a giant omphalocele was associated with increased postnatal morbidity [24]. …”

Patient characteristics are important determinants of neurodevelopmental outcome during infancy in giant omphalocele

“…It is generally classified into small, giant, and ruptured, depending on the size of the abdominal defect and/or its content. Giant omphalocele (GO) is defined as a defect that contains the majority of the liver (N75%), resulting in a significant loss of abdominal domain and an underdeveloped peritoneal cavity [1][2][3].…”

“…Postnatal survival of GO at tertiary centers has improved dramatically with reported rates of 70% to 90% [2][3][4]. With improved survival there has been an increasing focus on associated short-and long-term morbidity [1,4].…”