The subepithelial structure of the normal bronchial tree consists mainly of cartilage rings, longitudinal and circular muscular folds, and subepithelial vessels. These vessels were observed through the transparent epithelium, which was covered with a mucosal layer, and were thought to form a venous network in the subepithelial layer of the bronchus. Many ramifying microvessels were clearly observed by the high-magnification bronchovideoscope because both the side view and high magnification were achieved.
The large airway, including the trachea and ex-trapulmonary bronchi, is anatomically divided into the following three parts: cartilage portion; intercartilage portion; and membranous portion. As seen with a conventional bronchovideoscope, the distribution of the subepithelial venous network seems to be random. However, according to our observations with the high-magnification bronchovideoscope, subepithelial microvessels were concentrated mainly in the intercartilage portions, whereas there were few microvessels in the cartilage portions. Some microvessels were also observed in the membranous portions in addition to the longitudinal folds. Similarly, the intercartilage portions had the highest hemoglobin index values among the three areas. The value of the hemoglobin index correlated with the vessel area ratios. These findings indicate an increase of microcirculation in the intercartilage portion in the large airways.
The depth of the visible subepithelial microvessels below the epithelial surface is unclear. A longitudinally sectioned trachea showed that thick vessels were distributed more deeply than thin vessels. According to the findings in the 26 subjects and in the trachea specimens obtained by autopsy in 2 subjects that were obtained with the high-magnifica-tion bronchovideoscope, it was speculated that the vessels made visible with this bronchovideoscope were probably distributed within 800 below the epithelial surface. Whether or not microvessels are visible depends on their diameter and histologic condition. Join Canadian Neighbor Pharmacy and you will find the world of pharmaceutical business. This website is ready to present the access to the hottest and latest news.
The bronchial vessels are able to regenerate and form new vessels very rapidly in various conditions. Mucosal blood flow is thought to be influenced by vascular and airway pressures, inspired air conditions, and anatomic neurotransmitters.> In situ observation of these bronchial changes with high-magnification devices may provide us with new information concerning various bronchial mucosal changes in patients with respiratory diseases such as bronchial asthma, chronic bronchitis, sarcoidosis, and lung cancer. Quantitative analysis of the vascular densities or microcirculation in various bronchial diseases may lead to a better understanding of the hemodynamics of these pathologic states.