Aspirated foreign bodies (FB) into the respiratory tract often tend to lodge more commonly into bronchus than trachea. According to general belief a FB aspirated into trachea most frequently enters into the right bronchus leading to either collapse of the lung or obstructive emphysema because of its anatomical configuration. The current communication highlights the preponderance of left sided bronchial FB in my experience.

Twenty five cases of tracheo-bronchial FB were evaluated in the present study. There were 14 (56%) males and 11 (44%) females and 21 (84%) of them were below 2 years age. The time lag between the inhalation of FB and diagnosis varied from one day to five months. On clinical examination varying degrees of respiratory distress were noted: Skiagram of, chest was taken in all the cases. Obstructive emphysema was found in 12 (48%) and segmental collapse of the lung in 10 (40%) cases. In 3 cases of carinal FB, bilateral obstructive emphysema was detected. In 8 (32%) cases, FB was found in the right bronchus and in 14 (56%) cases in the left bronchus. Three left sided bronchial FB which were lodged for quite a long time were expelled spontaneously during investigation. In 14 cases of left sided bronchial FB, obstructive emphysema was found in 7 (50%) cases and segmental collapse in 7 (50%)' cases. Out of 8 right sided bronchial FB obstructive emphysema was found in 5 (62.5%) cases and collapse in 3 (37.5%) cases. Below 2 years of age, 52% of bronchial FB were found on left side and 24% on right side. Food related FB were found in majority of subjects (24 cases; (96%), commonest being the peanut (11 cases; (45.8%). Bronchoscopic removal of FB was carried out in 20 cases.

Various authors have described different dominant patterns of lateralisation of FB into the respiratory tract in their studies but no definite dominance has been established. Invariably aspirated FB lodge more frequently into the right bronchus because of its shorter, wider and less tortous anatomical configuration. This has been documented in majority of larger studies. However, some earlier reports(1-3), and the present study found the left bronchus as the commoner site, for FB lodgement. In another series of 140 cases of ,FB(4), the right bronchus was reported as the commonest site (58.5%) and food related substances constituted about 70%, nuts being the commonest. Similarly, in a series of 224 patients(5) 56% of aspirated FB were localised in the right bronchus, 39% in the left and 5% in the subglottic area. Two thirds of these FB were nuts. Right sided bronchial FB preponderance is thus an established concept in general when larger series have been reported Lateralisation depends on the size, nature of the FB and also on the age of the child. In the present study, though small in number, I observed a significant difference between the incidence of aspiration of FB into right and left bronchus. Fifty six per cent of FB were localised into the left bronchus and 32% into the right. Most of the children (84%) were below 2 years age. A Similar observation has been reported earlier(1-3). Laterlisation of FB into the left bronchus also depends on factors like tracheo-bronchial angulation and aerodynamics of tracheobronchial tree(2,3). A difference of less than 7° was more frequently associated with left side aspiration, arid 7° or more with right side. In the presence of lower pressure and significantly higher speed of air flow in the left bronchus than that in the trachea and right bronchus, FB can be easily sucked into it(2). The present study is only an, observation in a small group of patients to emphasize that left sided bronchial FB may be equally common.

Lakhani J .K.,
Consultant Pediatrician,
 Gadag 582 101,
Karnataka,
India.