Use of digital subtraction fluoroscopy to diagnose radiolucent aspirated foreign bodies in infants and children.

OBJECTIVES: Most tracheobronchial foreign bodies in children are radiolucent, and accurate diagnosis of such foreign bodies is not always easy. This can result in delay of diagnosis or misdiagnosis of foreign body aspiration. We report the usefulness and pitfalls of use of digital subtraction fluoroscopy (DSF) to diagnose radiolucent aspirated foreign bodies in infants.

METHODS: From 1991 through 1999, DSF was conducted for a total of 19 patients (ranged from 11 months to 4 years and 7 months in age (mean 1.8+/-0.9 years)) who were suspected to have radiolucent aspirated foreign bodies. Since DSF revealed abnormal findings in a trachea or main bronchus in 18 cases, inspection was performed for foreign body bronchofiberscopically. In the one remaining case, no abnormality was recognized on DSF, but since the symptoms at the time of onset strongly suggested aspirated foreign body, bronchofiberscopy was also performed.

RESULTS: Foreign body was verified bronchoscopically in 13 of 19 cases, and all 13 (100%) had abnormal findings on DSF, including obstruction of the trachea in two, obstruction of the bronchial lumen in nine, and indistinct visualization of the bronchial lumen in two. Bronchial stenosis was verified bronchoscopically in five of the remaining six cases, including mucus plug in three, granuloma in one and mucosal edema in one case. All five patients (100%) had abnormal findings on DSF, including obstruction of the bronchial lumen in four and indistinct visualization of the bronchial lumen in one. In the one remaining patient with normal findings of DSF, no foreign body or pathological bronchial changes were noted.

CONCLUSIONS: DSF was very sensitive in the diagnosis of foreign body aspiration and stenotic changes in the bronchial lumen. However, its diagnostic specificity for aspirated foreign body itself was not high (17%). Therefore, when abnormalities are found on DSF, we recommend to perform flexible bronchofiberscopy initially under general anesthesia via a tracheal tube. When a foreign body is verified, rigid ventilation bronchoscopy is successively performed to retrieve the foreign body.