Age- and Varicose Disease-Associated Changes in the Muscular Components of the Great Saphenous Vein

Varicose disease and other age-related vascular illnesses are extremely prevalent among the adult population. Despite this, research devoted to involutive changes in the veins of the lower extremities is rare and fragmented. Complex morphological evaluation of the wall of the vein related to age and varicose disease can add valuable data to fundamental geriatric and vascular medicine. <b>Objectives:</b> The study was designed to determine the age-related changes in the muscular component of the great saphenous vein and changes associated with varicose disease. <b>Materials and Methods:</b> A morphological study of a specimen of the great saphenous vein was conducted on 55 deceased individuals and 80 patients with varicose disease. Four age subgroups were identified: young, middle-aged, elderly, and senile. A total of 135 fragments of the great saphenous vein were evaluated. Histological, morphometric, and electron microscopic studies were performed. A quantitative analysis of the volumetric fraction of muscular components was calculated using the Shapiro-Wilk test, Kruskal-Wallis (ANOVA) and Mann-Whitney methods with Bonferroni correction. <b>Results:</b> Our study showed that the amount of connective tissue elements between bundles of smooth muscle cells increased with age. In patients with varicose disease, we observed an appearance of connective tissue fibers among smooth muscle cells, more pronounced with the disease progression. The structure of smooth muscle cell changes. Thus, we observed hypertrophy and phenotypic heterogeneity of cells with subsequent destruction of communicative contacts. The values of subintimal longitudinally arranged smooth muscle cells reached their maximum in middle age in both normal and varicose veins, while significant decrease occurred in elderly and senile patients. Quantitative indicators of circularly arranged smooth muscle cells of the middle layer did not change with age but significantly decreased in varicose disease. Age-related changes are characterized by an increase in the proportion of smooth muscle cells in the outer layer. In varicose veins, in young and middle-aged patients, the content of bundles of longitudinally arranged smooth muscle cells in the outer layer was higher compared to the age norm, with a significant decrease in senile age. <b>Conclusions</b>: The age norm of the muscular component of the great saphenous vein wall is characterized by an increase in the volumetric fraction of subintimal longitudinally arranged smooth muscle cells in middle age, the volumetric fraction of circularly arranged smooth muscle cells of the middle layer remains unchanged, and the volumetric fraction of bundles of longitudinally arranged myocytes of the outer layer increases. With age in varicose disease, sclerotic changes progress in the structure of the great saphenous vein at the tissue, cellular, and intracellular levels, leading to a decrease in the volumetric fraction of all muscular components of the great saphenous vein structure.