Demarcation Line

DEMARCATON LINE (from Latin demarcatio - demarcation), a zone of inflammation (see) and subsequent development of granulation tissue (see), which in the form of a line separates any dead substrate (e.g., the area of gangrene, a sequestrum, the cavity of an abscess, etc.) from healthy tissue. The development of the D. l. begins from the moment when inflammation in a given area, which previously did not have clear boundaries, takes on the character of a delimiting, demarcating process, at which time the main phenomena of inflammation are concentrated around the focus of necrosis itself. Macroscopically, in the area of the D. l., the tissue has a red, red-gray, gray, or gray-yellow color depending on the degree and duration of the inflammatory process, on the number of vessels in the forming granulation tissue, on the degree of infiltration of the elements of this tissue by lipoids, etc. A clearly noticeable D. l. is a sign considered favorable from a clinical point of view: it indicates the boundary of a necrobiotic or necrotic process, its localization; conversely, the absence of a D. l. is an unfavorable sign, indicating progressive necrosis of tissues. See also Gangrene.