A high resolution optical imaging device may enable diagnosis and characterization of benign and malignant diseases affecting the respiratory airways in vivo. This study describes the development and clinical evaluation of the first confocal bronchoscope for assessment of human airway wall and endobronchial morphology.
A confocal prototype was designed using Pentax bronchoscope parts (EB1970K). Patients (N=5) undergoing rigid bronchoscopy for various indications were imaged following IV administration of fluorescein sodium. The device was introduced into the airways via the rigid bronchoscope. Images were collected from the trachea, primary and secondary carina and any endobronchial mass. The results were compared with known structures from conventional histology.
Confocal bronchoscopy enabled microscopic imaging of cellular and subcellular structures of the respiratory mucosa in vivo. The pseudostratified columnar epithelium (including columnar cells and goblet cells) could be visualized. Images at increasing depth showed the lamina propria and microvasculature. Longitudinal folds in the mucosa enabled imaging in cross-section, showing alignment of epithelial cells along the basement membrane and cilia on the surface of cells. Below the epithelium, smooth muscle could be identified.
Confocal bronchoscopy provides potential for analyzing airway wall architecture and endobronchial abnormalities in histologic detail in vivo. The technique poses none of the risks of endobronchial biopsy and the potential for longitudinal assessment of disease processes.
Confocal bronchoscopy can detect early changes in the respiratory mucosa and submuosa. The technique may enable detection of dysplasia in the asymptomatic stage when curative treatment such as electrocautery or laser therapy and surgery can be applied. In benign diseases like asthma and emphysema, early determination of airway remodeling with confocal bronchoscopy could have significant therapeutic implications.
Ali Musani, No Financial Disclosure Information; No Product/Research Disclosure Information