SESSION TITLE: Bronchoscopy Poster Discussions
SESSION TYPE: Original Investigation Poster Discussion
PRESENTED ON: Wednesday, October 28, 2015 at 11:00 AM - 12:15 PM
PURPOSE: Accurate diagnosis is critical to both therapeutic decisions and prognostication in diffuse parenchymal lung diseases (DPLD). Surgical biopsy carries a high complication rate. Fibered confocal fluorescence microscopy (FCFM) can visualize lung tissue in vivo up to a cellular level and provide optical biopsies with minimal adverse events. This pilot study explores the value of FCFM in DPLD.
METHODS: FCFM images were obtained from multiple bronchopulmonary segments using a 1.4mm miniprobe (Cellvizio, Mauna Kea Technologies, Paris, France). The probe was inserted through the working channel of a flexible bronchoscope and the procedure was performed under moderate sedation in an outpatient setting. Morphometric and fiber pattern analyses of images were correlated with patients’ final diagnoses (based on a multi-disciplinary consensus).
RESULTS: 123 bronchopulmonary segments were imaged in 22 patients (16 males and 6 females). The mean age was 62.0±14.7 years. There were 14 chronic fibrosing interstitial pneumonia (CFIP) patients (12 idiopathic interstitial pneumonia, 2 Connective tissue disease related interstitial lung diseases) and 8 others (2 infectious pneumonia, 1 diffuse panbronchiolitis, 1 bronchiectasis, 1 sarcoidosis, 3 organizing pneumonia). The mean alveolar mouth fiber thickness was 14.5±5.2µm, the mean alveolar mouth diameter was 307.9±61.3µm. Previously published healthy control data were 10.0±2.7µm and 278±53µm respectively. Densely packed fiber pattern was seen in 12/14, 85.7% CFIP patients, and 3/8, 35.7% of other patients. The sensitivity of using the densely packed fibred pattern for diagnosing CFIP was 85.7% (95% CI, 57.2-97.8%), and specificity was 62.5% (95% CI, 24.7-91.0%).
CONCLUSIONS: This study shows that the alveolar mouth fiber thickness in DPLD patients is clearly distinct from healthy volunteers’ (P<0.0001). The measurement of alveolar mouth diameter had a high variability possibly due to dynamic changes during image acquisition and breathing. The densely packed fiber pattern may be predictive for CFIP.
CLINICAL IMPLICATIONS: FCFM has the potential to sub-classify DPLD without a high risk surgical biopsy.
DISCLOSURE: The following authors have nothing to disclose: Peng Meng, Gan Liang Tan, Su Ying Low, Angela Takano, Yuen Li Ng, Devanand Anantham
Fibered confocal fluorescence microscopy (FCFM) is an imaging technique, which can visualize the in vivo lung tissues up to alveolar cellular levels. It is using a point illumination and pinhole apparatus to block out of focus lights. This enables it to get high resolution images of thick biological materials. With the emerging technique of fiber based confocal microscopy, it has become small enough to visualize various body cavities such as gastrointestinal tract, bladder, and lung. FCFM has been most extensively used by gastroenterologist . In the first consensus report, FCFM is claimed to be non-inferior to standard biopsy for Barrettâs esophagus. And it is recommended for detection of gastrointestinal malignancies and inflammatory bowel disease. First pioneered by Thiberville in 2009, various research studies have been carried out to visualize respiratory tract. The results show that this technique has great potential in differentiation between malignant and benign lung lesions, identification of transplant rejection, detection of morphological changes due to DPLD conditions and real-time monitoring of patients in ICU. Currently, the elastin which is the endogenous fluorescence material and macrophages can be identified on confocal microscopy without staining or intravenous contrast. This study was using fibered confocal fluorescence microscopy called Cellvizio (Mauna Kea Technologies, Paris France). This machine utilizes a thin semi-flexible probe with a diameter of 1.4 mm, which is small enough to go through the working channel of a bronchoscope and advance into distal air space. And it can generate a field of view of 600 Ã 600 Âµm with a lateral resolution of 5Âµm under the illumination from a light source of 488nm wavelength.