Image-enhanced bronchoscopic evaluation of bronchial mucosal microvasculature in COPD

BACKGROUND Bronchial vascular remodeling is an underresearched component of airway remodeling in COPD. Image-enhanced bronchoscopy may offer a less invasive method for studying bronchial microvasculature in COPD. OBJECTIVES To evaluate endobronchial mucosal vasculature and changes in COPD by image-enhanced i-scan3 bronchoscopy and correlate them pathologically by analyzing bronchial mucosal biopsies. METHODS This case-control study analyzed 29 COPD patients (41.4% Global initiative for chronic Obstructive Lung Disease B [GOLD B] and 58.6% GOLD D) and ten healthy controls admitted at Alexandria Main University Hospital, Egypt. Combined high-definition white light bronchoscopy (HD WLB) with i-scan3 was used to evaluate endobronchial mucosal microvasculature. The vascularity was graded according to the level of mucosal red discoloration (ie, endobronchial erythema) from decreased discoloration to normal, mild, moderate, and severe increased red discoloration (G-1, G0, G+1, G+2, and G+3, respectively) and scored by three bronchoscopists independently. Bronchial mucosal biopsies were taken for microvascular density counting using anti-CD34 antibody as angiogenesis marker. RESULTS Different grades of endobronchial erythema were observed across/within COPD patients using combined HD WLB + i-scan3, with significant agreement among scorers (P=0.031; median score of G+1 [G-1-G+2]) being higher in GOLD D (P=0.001). Endobronchial erythema significantly correlated with COPD duration, exacerbation frequency, and body mass index (P<0.05). Angiogenesis was significantly decreased among COPD patients versus controls (10.6 [8-13.3] vs 14 [11-17.1]; P=0.02). Mucosal surface changes (including edema, atrophy, and nodules) were better visualized by the combined HD WLB + i-scan3 rather than HD WLB alone. CONCLUSION Combined HD WLB + i-scan3 seems to be valuable in evaluating mucosal microvasculature and surface changes in COPD, which may represent vasodilatation rather than angiogenesis.