Ultrasound imaging features of bronchial anthracofibrosis: A case-control study

To determine the ultrasound imaging characteristics of patients with bronchial anthracofibrosis (BAF) and identify clinical markers for prevention and treatment. We randomly selected 1243 participants (113 with BAF) who underwent bronchoscopy and received treatment at our institution between April 2018 and October 2019. BAF was classified as flat, deep-seated retracted, or black mucosal protruding based on microscopic findings. Ultrasound probes were used to determine the maximum thickness of the tube walls and submucosa. The average values of the submucosal and bony tissue areas in the BAF subtypes were compared. The BAF group included 13 participants with a history of tuberculosis (11.5%) and 57 participants with biofuel exposure (50.4%). The average exposure time was 17.4 +/- 6.2 years; BAF accounted for 10% of the bronchoscopies performed. The maximum tube-wall thicknesses of the deep-seated retracted (17.3 +/- 5.7) and black mucosal protruding (19.3 +/- 5.4) groups were significantly greater than those of the flat group (12.5 +/- 5.0; P < .05). The maximum thicknesses of the submucosa in the deep-retracted (9.8 +/- 3.0) and black mucosal protruding (14.5 +/- 5.0) groups were significantly greater than that of the flat group (6.6 +/- 3.5; P < .05). The ratios of bone tissue in the flat and black mucosal protruding groups were 33.3 +/- 9.3% and 34.9% +/- 12.1%, respectively. The ratio in the deep-seated retracted group (65.2% +/- 8.7%) was significantly reduced (P < .05). The flat group showed no significant change (P > .05). Differences in BAF airway remodeling among different subtypes may lead to varying clinical symptoms. Analyzing the characteristics of BAF airway remodeling and the regulatory pathway may provide new clues for treatment.