Endoscopic Evaluation of Angiogenesis in the Large Airways of Horses with Heaves Using Narrow Band Imaging

Abstract

BackgroundHeaves is a severe debilitating condition of horses, characterized by lower airway inflammation and permanent structural changes of the bronchial wall. Chronic inflammation promotes the formation of new vessels, a phenomenon known as angiogenesis. Narrow band imaging (NBI) endoscopy is a noninvasive technique that enhances the visualization of submucosal vessels, and commonly is employed for the study of angiogenesis in human patients.ObjectivesUsing NBI, we aimed to determine whether or not the central airways of horses with heaves undergo angiogenesis.AnimalsHorses with heaves during exacerbation of the disease (n = 5) and healthy controls (n = 6).MethodsA library of NBI images was established from previously recorded videoendoscopies. Images were acquired by an operator blinded to horse ID. Images were obtained from 3 sites: 130 from the trachea (14 ± 9.3 [mean ± SD] images per horse with heaves and 10 ± 5.4 from controls; P = .45), 58 from the carina (5.4 ± 3.2 from horses with heaves and 5.2 ± 2.8 fromn controls; P > .99) and 167 from the intermediate bronchi (17.8 ± 6.7 from horses with heaves and 13 ± 5.6 from controls; P = .17). Using dedicated stereology software (NewCAST, Visiopharm; Denmark), the volume density of superficial and deep vessels was calculated blindly by point counting at each site for all horses.ResultsIn the trachea, the volume density of superficial vessels was increased in horses with heaves compared to controls (P = .02). No difference was found between groups for the volume density of both superficial and deep vessels at the carina or intermediate bronchi.Conclusion and Clinical Relevance NBI imaging of the airways was easily performed in standing sedated horses.

Cell engraftment, vascularization, and inflammation after treatment of equine distal limb wounds with endothelial colony forming cells encapsulated within hydrogel microspheres

“…In this study, we utilized a histomorphometric software program (Visiopharm, Horsholm, Denmark) to quantitatively evaluate immunohistochemical stain densities in a semi-automated, unbiased manner [31,32]. This histomorphometric algorithm-based analysis has also been used to quantify degree of angiogenesis in equine large airways [33], however a common approach for wound healing assessment in the equine involves a semi-subjective scoring system [3,28,29]. One study of human patients diagnosed with breast cancer found that the histomorphometric software program outperformed traditional pathologist-based analysis of prognostic histologic biomarkers [34].…”

Bronchial angiogenesis in horses with severe asthma and its response to corticosteroids

“… 18 Although several studies have identified the presence of angiogenesis in humans with asthma, 19 , 20 , 21 , 22 with an increased number of subepithelial vessels and vascular area in lung tissue, 11 , 23 literature on lung angiogenesis in asthmatic horses is scarce. A 2012 study 24 showed an increased vascular density of superficial tracheal vessels in asthmatic horses, when evaluated by narrow‐band imaging. However, no differences were observed at the level of the bronchi, conflicting with results obtained in humans.…”