Important information about wounds (related to scar tissue),

For those who are involved with removal surgery, after removal, there is a process where the wound heals, right? Since it heals inside the nose in an open state, not by suturing, I’m posting this because knowing that process may help with taking some kind of action. [Stages of wound healing] When tissue is damaged for any reason, the normal biological rhythm is disrupted, and a response to heal the wound begins. The wound-healing process can be divided into 1) inflammatory phase 2) epithelialization phase 3) proliferative phase 4) maturation phase. These 4 stages of healing can be seen in all wounds, and each stage proceeds continuously while overlapping to some extent, without clear boundaries. The speed and degree of healing differ depending on the tissue and the method used to close the wound. In other words, when a wound is surgically sutured, it heals with collagen accumulating to a degree similar to normal, and epithelialization and wound contraction occur less. However, when a wound heals while left open, more collagen accumulates, epithelialization occurs over a wider area, and wound contraction becomes more severe. 1) Inflammatory phase It plays the most important role among the 4 stages of wound healing. This is because if this phase continues for a long time, the next wound-healing process is delayed. In this phase, destroyed tissue debris, foreign substances, necrotic tissue, and so on must be cleaned out by acute and chronic inflammatory cells before moving on to the next phase. 2) Epithelialization phase The skin consists of the epidermis and dermis, and the part on the skin surface is the epidermis. When skin is lost due to trauma, the skin covers the area at a rapid speed. In this process, epithelialization is when the epidermis of the skin covers the wound. This epithelialization occurs without the dermis. The epithelialization process in the traumatized area involves cells dividing and migrating without differentiating. Epithelial cells originally differentiate, perform the specialized functions of epithelial cells, then die and become keratin. However, if epithelial cells are injured while carrying out this process, the epithelial cells stop differentiating and the basal cells within 2 mm from the wound edge divide 40 times faster than usual. Thus, 24-48 hours after injury, the wound surface begins to be covered with epithelium, and cell division reaches its peak at 48-72 hours. 3) Proliferative phase When a wound occurs in the body, various immune cells gather. The various cytokines they produce cause proliferation of fibroblasts and generation and accumulation of the interstitium, allowing the wound to heal. It has been found that in this process, the large amount of cytokines produced causes an excessive reaction, leading to scar formation. Therefore, efforts are continuing to regulate these cytokines so that fewer scars form. The proliferative phase begins 5-7 days after injury and continues for 2-3 weeks, and during this period the wound is filled with new connective tissue called granulation tissue. During the inflammatory phase, the wound becomes clean, capillary buds grow into it, and fibroblasts gather. When the proliferative phase begins, the gathered fibroblasts synthesize collagen fibers, the main component of connective tissue, giving the wound tensile strength. The proliferative phase is more active in younger patients than in elderly patients, and the mid-20s are generally regarded as the borderline age. Before this point it is active, and after this point it gradually becomes less active. The tensile strength of the wound increases rapidly from the end of the first week, reaches its peak on day 42, and during this period metabolism proceeds actively in the wound until it reaches the maturation phase. After suturing, tensile strength reaches its peak at around 60 days. 4) Maturation phase The maturation phase is the stage in which granulation tissue containing many fibroblasts changes into scar tissue packed with collagen fibers. It begins on day 15 after injury and continues for as long as 18 months. During that time, the scar contracts from all directions, excess water drains into the spaces between cells, and the collagen becomes firmer. The number of fibroblasts decreases, and the numerous blood vessels become occluded. While the maturation phase is actively progressing (for 2 months), the scar may form excessively and consistently, becoming red and raised, but after about 6 months the collagen gradually matures, the blood vessels are compressed, and the scar becomes increasingly thinner and lighter in color. In the case of a normal scar, as the scar matures over 6-12 months, it gradually becomes softer and thinner. The color lightens, making it less noticeable. However, if collagen production and breakdown are still active even after 6 months, it becomes a hypertrophic scar (scar tissue) or keloid.