Granulation tissue
Granulation tissue refers to the “filling tissue” of a wound that is created during the granulation phase. It closes the wound and forms the basis for the formation of new skin cells and blood vessels. Externally, this type of tissue often appears reddish with a granular surface.
It contains connective tissue cells (fibroblasts), which are responsible for the new formation of connective tissue and skin, as well as newly formed tiny blood vessels (capillaries). If no or only little granulation tissue is formed, the wound healing phases cannot be completely completed, as the missing vessels do not allow for a sufficient oxygen supply. In this case, the wound edges become greasy and discolor strongly red to bluish. This can be remedied by scraping off the wound edges with a sharp spoon (curettage), whereby the old wound tissue is removed, thus creating space for healthy new formation.
Wound healing phases in bone
Wounds in the mouth have a special feature in addition to the typical wound healing phases, i.e. cleansing phase, granulation phase and regeneration phase. In healthy people, the oral cavity is covered by a film of saliva. In addition to water, mucus and digestive enzymes, saliva also contains the protein histatin.
This protein contains a lot of histamine (an amino acid) and prevents invading germs such as bacteria or fungi from spreading. For this reason, healing of wounds in the mouth is less complicated, and infections are less frequent than in other parts of the body. The wound healing of a decubitus (extensive skin damage caused by pressure and shear forces) follows the 3 main phases of wound healing, just like the healing of other wounds.
However, since a decubitus almost always develops on parts of the body that are exposed to constant pressure, for example on the coccyx or the shoulder blades in bedridden patients, this type of chronic wound is extremely protracted and difficult to treat. The body’s own healing process should be supported if possible in order to close the wound. In the first phase, the cleansing phase, it is important to help the body to keep the wound free of germs.
Dressings that absorb blood and wound secretions quickly are beneficial, but must be changed up to six times a day. Only in this way can bacteria and other germs be reliably removed from the wound. In order to advance the subsequent granulation phase, the decubitus can be “cleared” surgically.
In this process, dead (necrotic) skin areas are removed until a clean wound bed has been formed. This makes it easier for the body to form granulation tissue from which new skin can develop. Finally, during the regeneration phase it is important to position the affected area of the body with as little pressure as possible in order not to disturb the wound healing process and to avoid a new pressure sore.
Frequently used aids for this are “decubitus mattresses” and frequent repositioning of the bedridden patient. If the body is optimally supported during the wound healing phases, even longstanding decubitus ulcers can be healed.
