Air test as a simple method of screening for Hirschsprung's disease

AIM: To present the technique and the diagnostic accuracy of the air test to diagnose Hirschsprung's disease (HD). MATERIALS AND METHODS: Children who attended hospital for chronic constipation (CC) between January 2012 and December 2016 for whom the air test was performed were enrolled. The test was conducted during contrast enema under fluoroscopic observation using 20-50 ml injections of air into the rectum through a 10 F Nelaton catheter. The demographics, results of the air test, and additional examinations, as well as the outcomes of subsequent treatments were analysed retrospectively. RESULTS: The air test was conducted in 179 patients (median: 3 years, range: 0-14 years), and was positive in 150 and negative in 29 cases. Of the 29 patients with negative results, four were diagnosed with HD by rectal suction biopsy (RSB). Of the remaining 25 patients, RSB was conducted in seven and HD was excluded in all cases. In all 150 patients with positive air test results, CC was adequately controlled with conservative treatment. The sensitivity and specificity of the air test were 100% (4/4) and 85.7% (150/175), respectively. CONCLUSIONS: The air test can be used as a new non-invasive screening method for HD, performed simultaneously with contrast enema. (C) 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.