Tube Position and Culture in the Nasal Cavities of Patients Treated with Silicone Tube Intubation

Purpose: To evaluate the relationship between the position and direction of a silicone tube in the nasal cavity after silicone tube intubation and clinical features.Methods: This study included 70 eyes of 52 patients who were diagnosed with nasolacrimal duct obstruction and had silicone intubation surgery.The position and direction of the silicone tube were compared after tube intubation and before extubation.An intranasal swap culture was performed before tube intubation, and the removed silicone tubes were cultured.Results: The length of the silicone tube decreased from 8.7 ± 3.1 mm after intubation to 7.3 ± 3.1 mm before extubation, and the direction of the tube moved backward in the nasal cavity (p < 0.05).The bacterial culture rate changed from 94.3% before intubation to 75.7% before extubation.The most common Gram-positive bacteria (both preoperative and postoperative) was coagulase-negative Staphylococcus aureus.The most common Gram-negative bacteria were converted from Klebsiella aerogenes to Stenotrophomonas maltophilia.The fungal culture rate changed from 7.1% to 51.4%, and the culture rate increased when the silicone tube direction was moved backward (p < 0.05).The length and direction of the silicone tubes were not correlated with clinical symptoms or changes in eyelid height. Conclusions:The length of the silicone tube in the nasal cavity decreased, and the tube tended to move in a posterior direction after silicone tube intubation.Considering the increase in the intra-nasal fungal culture rate, it is better to place the silicone tube in the anterior part of the nasal cavity from the inferior meatus.To clarify further the fungal infection and its clinical findings, a study of cultures with respect to location in the lacrimal system would be required.