Experimental nasal intubation: a study of changes in nasoantral mucosa and bacterial flora

To investigate the local effects in a nasal cavity and its adjacent sinuses of long-term detention of an endonasal tube, with special attention to inflammatory pathology and microbiology.

Experimental rabbit study.

Four groups of 4 rabbits, in all 16, were unilaterally nasally intubated and evaluated macroscopically, histopathologically, and bacteriologically after 1, 2, 4, and 8 weeks, respectively.

At first, in the 1- and 2-week groups to the 4-week group, histopathology, such as degeneration of olfactory mucosa, squamous cell metaplasia, and polyp formations, was observed together with frequent opportunistic bacterial findings in the nasal cavity. Later, in the 4- and 8-week groups, inflammatory mucosal changes, such as septal increase of connective tissue, goblet cell hyperplasia, and epithelial invaginations, were found in the nasal cavity containing a tube. A concomitant increase was found of commensal bacteria adjacent to the tube and the similar bacterial findings in the ipsilateral maxillary sinuses. However, there were no signs of inflammatory reactions in the sinuses.

Our investigation points to the tube as the cause of local goblet cell hyperplasia with an increased mucus production, and as a food source for the commensals with a marked increase of the amount of bacteria. The positive bacterial cultures from the maxillary sinuses might be considered to be colonization. However, because of the possibility of contamination, improved sampling techniques are required, as are further studies.