Role of vascular endothelial growth factor A in children with acquired airway stenosis

Objectives: Vascular endothelial growth factor A (VEGF-A) is important in the angiogenic response for wound healing. This study investigated whether VEGF-A may play a role in the pathogenesis of acquired airway stenosis. Methods: Eight lesions from 5 pediatric patients with subglottic stenosis after airway reconstruction (N = 4) or prolonged intubation (N = 1) and normal laryngeal tissue from 5 autopsy patients were included. Formalin-fixed sections of subglottic tissue from each patient were examined by in situ hybridization for the presence of messenger RNA (mRNA) for VEGF-A, vascular endothelial growth factor receptor 1 (VEGFR-1), and vascular endothelial growth factor receptor 2 (VEGFR-2). Results: Strong expression of VEGF-A mRNA was noted in hyperplastic squamous epithelium overlying granulation tissue. Strong expression of VEGFR-1 and VEGFR-2 was noted in the endothelial cells within granulation tissue. No strong labeling of VEGF-A mRNA or its receptors was noted in 2 specimens with mature scar tissue or in the control specimens. Conclusions: The angiogenic growth factor VEGF-A is strongly expressed in hyperplastic epithelium overlying granulation tissue in airway stenosis. Also, VEGFR-1 and VEGFR-2 mRNAs are strongly expressed in the endothelial cells of granulation tissue. This finding suggests an important role of VEGF-A in the pathogenesis of airway scar formation and stenosis.