Results: In vivo pulmonary microcirculation imaging was possible in 7/7 elastase animals and in 6/7 controls. Using FCFM, intercapillary distances and alveolar facets diameters were found significantly higher in the elastase group compared with controls (49.5 vs. 41.8 µm p < 0.001, and 118.5 vs. 95.1 µm p < 0.001, respectively). Ex vivo mean interwall distance (MIWD) was correlated with the alveolar facets diameters measured in vivo (rs = 0.65 ; p = 0.016).
Methods: 14 Sprague-Dawley rats were assigned to intratracheal instillation of porcine pancreatic elastase (n = 7) or saline (n = 7). The subpleural microcirculation was assessed using FCFM in spontaneously breathing rats, through a 2mm thoracic window using a continuous aspiration system, after I.V. injection of fluorescein-dextran. FCFM sequences were recorded and the image analysis was performed separately by two observers, blindly to the animal group. Fluorescence intensity (FI), maximal intercapillary distances, and alveolar facets diameters measured with FCFM were compared between groups, and to ex vivo lung morphometric measurements (MIWD).
Conclusion: FCFM allows the quantitative assessment of the microcirculation alterations due to emphysema in vivo.View Article