From May 1, 2000 to May 1, 2020, 3557 patients underwent bronchoscopy and were defined diagnosed as FBA in our department. Of these patients, 35 (0.98%) met the inclusion criteria for occult FBA. 23 (65.7%) were male and 12 (34.3%) were female, and the M: F ratio was 1.92:1. The average age was 3.60 years (range 9 months-12 years). Most of the patients were younger than 3-years-old (25 patients, 71.4%). The average course was 3.69 months (range 4 days-4 years).
These patients were misdiagnosed with pneumonia, asthma, tuberculosis, and bronchitis as out-patient. Among the teaching attending rounds, the first diagnosis was pneumonia (30 cases, including 10 cases of persistent pneumonia, 4 cases of chronic pneumonia, 4 cases of severe pneumonia), 3 cases of asthma (including 2 suspected cases), 1 case of bronchitis, and 1 case of bronchiectasis. Suspected diagnoses were FBA (20 cases), tuberculosis (13 cases), asthma (11 cases), bronchiectasis (7 cases), bronchopulmonary dysplasia (6 cases), and idiopathic pulmonary hemosiderosis (2 cases).
All patients denied the history of FBA. All the 35 patients had different degrees of cough and there was no obvious tracheal deviation or tracheal tapping sounds on physical examination. The most common positive sign was wheezing (18 cases) and 7 patients had negative signs (Table 1).
In laboratory tests, the results of blood routine showed an increase in white blood cell (WBC) count in 25 cases, mainly with an increase in neutrophil count. C-reactive protein (CRP) increased in 8 patients. Fourteen cases were positive for sputum bacteria culture (one case of co-infection), six cases were positive for virus antibodies (one case was co-infection), and two cases were positive for the specific DNA of mycoplasma pneumoniae (MP). Sputum smear and culture of tuberculosis were negative (Table 1).
Radiological findings after admission showed that no direct signs of FB. Occult FBAs are mainly manifested in pneumonia, atelectasis, and lung consolidation on the basis of images (Table 1).
Thirty-five patients were treated with bronchoscopy and alveolar lavage for long-term symptoms, abnormal radiological findings, and poor treatment outcomes (Figure 1). The time from admission to undergoing bronchoscopy for diagnosis of FBA was 1-18 days (average 3.26 days). All the patients were found to have FB under the fiberoptic bronchoscope (two cases were found by repeated fiberoptic bronchoscopy). Nineteen cases were located in the main bronchus, 12 cases were located in the lobar bronchus, and 4 cases were located in the segmental bronchus. Patients underwent rigid bronchoscopy (Karl Storz GmbH & Co KG, Tuttlingen, Germany) for FBs extraction under combined intravenous anesthesia with airway surface anesthesia. The position of FBs in 30 patients remained consistent under rigid bronchoscopy and the position changed in 5 patients. The location of the FBs in the tracheobronchial tree is shown in Table 2. After bronchoscopy, 8 patients had a transient fever, 6 patients presented as slightly irritable, and 1 patient had blood-streaked phlegm. No serious adverse events such as asphyxia, pneumothorax, dyspnea, or arrhythmia occurred.
Extracted FBs were divided into organic or inorganic types, the type was in the great majority organic (77.1%). The most common organic FBs were peanuts (n=10) and the most common inorganic FBs were pen caps (n=5). Because the majority of the FBs stay in the bronchial tubes for a long time, there are granulation tissue proliferation, hyperemia and swelling, and even erosion with purulent secretions in the bronchus (Table 2).
After the FBs were removed, the patient continued to be treated with anti-infective drugs and support care. The time from admission to discharge was 3-35 days (average 8.74 days). The patients had no fever before discharge and the symptoms of cough and wheezing were significantly relieved. One patient coughed up a small amount of residual FB after rigid bronchoscopy. The discharge diagnosis of all patients was FBA with pneumonia, 7 patients had bronchiectasis (including 2 suspected cases), and 5 patients had respiratory failure.
The follow-up time was 6 months – 4 years (average 2.35 years). The patients were recovered completely with full lung expansion after a mean duration of 3 months. Thirty-four children had no new pulmonary lesions in the chest image during follow-up. One patient required a pulmonary lobectomy because of bronchiectasis accompanied with lung abscess formation.