Stasis (z4223)

STASIS (Latin: stagnatio) of blood, lymph, and various secretions in glandular organs is a not uncommon phenomenon occurring under various pathological, and more rarely, physiological conditions. By stasis of blood, it is generally understood to mean, primarily, stasis of venous blood, observed especially often in cases of mechanical obstructions to venous flow (e.g., in heart defects, thrombi in veins, etc.), as well as in certain reflex-nervous (angioneuroses) and inflammatory conditions. Such stasis of blood is often accompanied by the subsequent development of stases, thrombi, phenomena of diapedesis, edema, and, on the part of the corresponding organs, by changes in their color (see Cyanosis), consistency (cyanotic induration, brown induration), and size (enlargement), up to the development of so-called elephantiasis (see Elephantiasis). In venous stasis in mucous membranes, an increase in the secretion of their glands is noted (congestive catarrhs). Stasis of lymph (lymphostasis, chylostasis), in addition to the dilation of lymphatic vessels, can cause the transudation of lymph into adjacent cavities (chylous, pseudochylous ascites, hydrothorax) with indurative and hypertrophic changes in the corresponding vessels, lymph nodes, and surrounding tissues (e.g., elephantiasis). Stagnant lymph can be partially absorbed by tissues and also undergo secondary changes, for example, in the sense of becoming saturated with lipoids. Stasis of glandular secretion is most often associated with mechanical obstacles to its excretion through the excretory duct, which may, in turn, depend on the presence of stones, parasites, tumors, or scars in the duct, as well as on the thickening of the secretion itself, etc. The direct effect here will be the dilation of the proximal parts of the excretory ducts of the given organ, and subsequently, depending on the nature of the secretion and the properties of the organ, various changes in the latter, such as: atrophic, necrobiotic, and sclerotic processes (e.g., biliary cirrhosis of the liver in congestive jaundice), as well as sometimes inflammatory diseases, since the stasis of secretion is accompanied not only by changes in its physicochemical properties and reaction, which facilitates infection in general, but also creates the danger of the infection ascending to the origins of the gland's excretory ducts—into the very parenchyma of the latter. Stagnant secretion thickens over time, during which calcium salts may be deposited in it. In connection with the stasis of secretion along the course of the excretory ducts, dilations of the ducts and even cysts often develop.