Wound Bed Preparation: The Science Behind the Removal of Barriers to Healing

Stuart Enoch, MBBS, MRCSEd, MRCS (Eng), Keith Harding, MB ChB, MRCGP, FRCS


Wounds. 2003;15(7) 

In This Article

Necrotic Tissue and its Accumulation in Chronic Wounds

Necrotic tissue is dead tissue, which usually results from an inadequate local blood supply. Necrotic tissue contains dead cells and debris that are a consequence of the fragmentation of dying cells. Necrotic tissue changes color from red to brown or black/purple, as it becomes more dehydrated. Finally, it forms a black, dry, thick, and leathery structure known as eschar. This can be seen in a wide variety of wound types, including burns and all types of chronic wounds. In contrast, slough is a yellow fibrinous tissue that consists of fibrin, pus, and proteinaceous material. Slough can be found on the surface of a previously clean wound bed and it is thought to be associated with bacterial activity.[37] The accumulation of necrotic tissue or slough in a chronic wound is of major clinical significance, because it is thought to promote bacterial colonization and prevent complete repair of the wound.

Recently, the term necrotic burden has been proposed as an all-encompassing term to describe necrotic tissue, excess exudate, and high levels of bacteria present within dead tissue.[33] Due to the underlying pathogenic abnormalities in chronic wounds and the altered biochemical and cellular environment, necrotic tissue tends to continually accumulate.[33,38] However, it is not always feasible to fully remove the underlying pathogenic abnormality, making it even more essential to adequately prepare the wound bed. If the necrotic burden is allowed to accumulate in the chronic wound, it can prolong the inflammatory response, mechanically obstruct the process of wound contraction and impede reepithelization.[39]