Исследована эффективность оригинального метода для изучения микроциркуляторного русла при нормальной анатомии и патологической неоваскуляризации. Исследовали кровеносные сосуды, ткани вокруг стента из лёгочной артерии и титановой пластины после подкожной имплантации, атеросклеротическую бляшку и подвергшийся рестенозу сосудистый стент. Образцы фиксировали в формалине и тетраоксиде осмия, заключали в эпоксидную смолу, подвергали шлифовке и полировке, контрастировали уранилацетатом и цитратом свинца. У всех нативных сосудов обнаруживали значительное количество vasa vasorum. Вблизи стента из лёгочной артерии и металлических пластин наблюдали многочисленные новообразованные сосуды малого диаметра. Выраженность неоваскуляризации при атеросклерозе и при рестенозе каротидного стента существенно отличалась. Разработанный метод может быть использован для оценки состояния микроциркуляторного русла.

Aim. To apply our original technique of sample preparation, epoxy resin embedding, and backscattered scanning electron microscopy for the assessment of microvessels in health and disease. Materials and Methods. The study was performed on rat aorta, bovine internal mammary artery, human internal mammary artery and saphenous vein, stent excised from the right ventricular outflow tract, titanium nickelide plate explanted from the rat subcutaneous air pouch, carotid atherosclerotic plaque, and neointima from in-stent restenosis. All samples were fixed in formalin (24 h), postfixed and stained in osmium tetroxide (60 h), dehydrated in ascending ethanol series, stained in uranyl acetate in 95% ethanol (5 h), impregnated into epoxy resin (30 h), embedded into fresh epoxy resin, grinded, polished, and counterstained with lead citrate (7 min). Visualisation was performed using backscattered scanning electron microscopy upon sputter coating with carbon. Results. We detected large quantities of first-order vasa vasorum characterised by elongated endothelial cells and visible basement membrane in the adventitia and perivascular adipose tissue of or normal blood vessels. In contrast to arterial vasa vasorum, venous vasa vasorum contained one or two layers of smooth muscle cells and did not have a connective tissue sheath, yet arteries contained a few venous vasa vasorum and vice versa. Multiple neovessels of a relatively large caliber were detected after right ventricular outflow tract stenting. Reactive neovascularization upon the implantation of metal plates was characterised by a large amount of small-caliber blood vessels in the adjacent connective tissue. Vasa plaquorum had intact endothelial cells and basement membrane and notably differed in regard to the number of microvessels in primary carotid atherosclerotic plaques and neointima from in-stent restenosis. Combination of platelets inside the lumen, endothelium, and basement membrane permitted differentiation of microvessels from sample preparation artifacts. Conclusion. Our technique may be successfully used for the relatively high-resolution visualisation of microvessels, particularly in blood vessels, atherosclerotic plaques, and tissues containing metal implants.