Saline-Aided Ultrasound Versus Upper Gastrointestinal Series in Neonates and Infants With Suspected Upper Gastrointestinal Obstruction: A Prospective Multicenter Comparative Study

BACKGROUND. Use of upper gastrointestinal (UGI) series to diagnose UGI obstruction in neonates and infants has raised concern about increased radiation sensitivity of developing organs. OBJECTIVE. The purpose of this study was to assess the diagnostic performance of saline-aided ultrasound (US) in comparison with UGI series in evaluation for UGI obstruction in neonates and infants. METHODS. In this prospective multicenter study at three hospitals, inpatients were enrolled who were younger than 1 year and had suspected UGI obstruction between June 2015 and May 2018; patients with US evidence of malrotation or pyloric stenosis were ineligible. Enrolled patients underwent both saline-aided US (saline solution administered through a nasogastric tube) and UGI series. Surgical findings or at least 1-year of clinical follow-up findings served as the reference for presence of UGI obstruction. UGI obstruction was classified in terms of level (proximal vs distal) and cause. Two radiologists independently interpreted saline-aided US examinations to assess interobserver agreement and then reached consensus. Two other radiologists assessed upper GI series in consensus. Diagnostic performance for the presence and level of UGI obstruction was compared between modalities. Causes of obstruction were assessed with saline-aided US. RESULTS. A total of 209 neonates were included (116 boys, 93 girls; median age, 5 days; 124 (59.3%) patients had UGI obstruction (proximal in 108 patients). Saline-aided US had strong interobserver agreement for presence (kappa = 0.87) and level (kappa = 0.85) of obstruction. For presence of UGI obstruction, accuracy, sensitivity, and specificity were 94.7%, 98.4%, and 89.4% for saline-aided US and 89.5%, 95.2%, and 81.2% for UGI series. For obstruction level, accuracy, sensitivity, and specificity were 90.3%, 97.2%, and 56.3% for saline-aided US versus 87.1%, 92.6%, and 50.0% for UGI series. Accuracy for presence was significantly higher for saline-aided US (p = .02); otherwise, these metrics were not different between tests (p > .05). For causes of UGI obstruction (annular pancreas, duodenal web, duodenal atresia, and duodenal stenosis), the accuracy of saline-aided US ranged from 75.0% to 95.2%. CONCLUSION. Saline-aided US has high diagnostic performance for presence and level of UGI obstruction in neonates and infants, comparing favorably with UGI series. Saline-aided US may have additional utility in evaluating causes of obstruction. CLINICAL IMPACT. Saline-aided US may serve as an initial screening modality for UGI obstruction in neonates and infants.