"Although airway fluoroscopy accurately diagnoses the cause of stridor in some children, its low sensitivity may necessitate further diagnostic evaluation of negative results, according to a report in the April issue of the
Archives of Otolaryngology - Head and Neck Surgery.Dr. Eric Berg and colleagues from Emory University, Atlanta, Georgia examined the role of fluoroscopy in evaluating stridor in children by reviewing 39 cases in which patients were examined first by airway fluoroscopy and later by endoscopy.
Twenty-three (59 per cent) of the children received a different diagnosis based on endoscopy from the diagnosis made by airway fluoroscopy, the investigators report.
Among the four most common abnormalities diagnosed by airway endoscopy, fluoroscopy was highly specific in identifying airway stenosis (100 per cent), laryngomalacia (100 per cent), airway mass lesions (100 per cent), and tracheomalacia (94 per cent).
However, airway fluoroscopy proved to have low sensitivity for identifying these conditions: 69 per cent for airway stenosis, 27 per cent for laryngomalacia, 43 per cent for airway mass lesions, and 20 per cent for tracheomalacia.
"Our findings call into question the reliability of diagnoses made by airway fluoroscopy," Dr. Berg and colleagues write. "In particular, 16 of 18 'normal' airways on airway fluoroscopy were found to have some abnormality on endoscopy."
"Negative fluoroscopic study results require further diagnostic evaluation if clinically indicated," they conclude. "Therefore, the value of airway fluoroscopy as a screening tool remains uncertain."
"The ideal study to define the utility of airway fluoroscopy in the evaluation of pediatric stridor would be a prospective design in which all subjects undergo both airway fluoroscopy and endoscopy," the researchers add. "Unfortunately, the added risk and expense encountered through such a trial make it unreasonable, if not unethical, to conduct."
Arch Otolaryngol Head Neck Surg 2008;134:415-418."
