Evaluation of lung pathology in an experimental model of tracheal foreign body

This experimental study was undertaken to evaluate the pathological changes caused by foreign body aspiration (FBA) on the lungs.

The study was performed on 19 Wistar albino rats. The rats in the control group (n = 5) were not subjected to any procedures. The rats in the sham group (n = 5) underwent tracheostomy, and a feeding tube was inserted into each rat. In nine rats in Group 1 (the study group), small lead marbles were placed into their trachea in addition to the procedures applied in the sham group. Lung tomography was performed on all the rats. The lungs, heart, and trachea were removed en bloc under ketamine hydrochloride anesthesia and fixed in 10 % formalin solution at the end of one week. The lung tissues were examined for FB, perivascular and peribronchial inflammatory cell infiltration, intra-alveolar bleeding, and post-obstructive emphysema.

Tomography revealed FB in 4 rats and pathological evaluation showed FB in 7 rats. All the rats in Group 1 had peribronchial inflammation, while 7 rats (77.8 %) had perivascular inflammation. The sham and control groups were collectively referred to as Group 2 because of statistically similar findings. Group 1 and Group 2 significantly differed with respect to the findings of perivascular and peribronchial inflammation, intra-alveolar hemorrhage, and emphysema (p < 0.05). In Group 1, inflammation was detected in the opposite lobe of the lungs, although there was no FB.

The presence of inflammation in the opposite lobe of the lungs where no FB was placed and in even those rats that expectorated the FB suggests that FBA is not a local pathology but a general pathology inducing inflammation in the whole lung. Thus, urgent removal of a foreign body is vital.