Volatile Organic Compounds Arising from Tracheobronchial Stent-related Biofi lm Formation Detected in Patients' Breath by Ion Mobility Spectrometry

Background: Tracheobronchial stent-related biofi lm formation encountered in interventional pulmonology that can result in pneumonia and in tissue granulation. Breath analysis by means of ion mobility spectrometry (IMS) has been reported for detection of volatile organic compounds (VOCs) indicative of bacteria biofi lm. We hypothesized that IMS can detect specifi c VOCs in patients with bacterial biofi lm formation resulting from tracheobronchial stent placement, and we tested our hypothesis in a prospective study conducted between October 2011 and October 2012. Methods: During the study period, stent placement, removal, or replacement was performed in 21 patients with tracheobronchial stenosis. A silicone stent was used in 11 of these patients. In 11 cases, 5 cases were placement procedures and 6 cases were replacement or removal procedures. Breath samples were obtained from these 6 patients before and after stent removal or replacement, and the samples were analyzed by IMS. Peaks were characterized with the use of Visual Now 2.2 software (BS P23, limonene (p < 0.05); P24: 2,2,4,6,6-pentaheptylmethane (p < 0.05); P31, 1-octanol (p < 0.05); and P35: phenylacetaldehyde (p < 0.05). Conclusions: Using IMS, we were able to assess the degree of Pseudomonas aeruginosa biofi lm formation resulting from stent placement. IMS breath analysis in conjunction with clinical symptoms will provide for non-invasive assessment of the need for stent replacement or removal.