Wound Healing

Inflammation

________ serves to remove the danger which is usually associated with tissue damage and death.

Growth Factors

________ affect cell proliferation, cell migration, angiogenesis, tissue matrix formation, and the deposit of collagen (fibrosis)

Macrophages

________ are believed to be the architects of wound healing and tissue repair.

Ulcer formation

________: wound does not heal, no scab.

impairs repair

Systematically ________: age, pre- existing conditions (diabetes, malnutrition, atherosclerosis), drugs (steroids, chemotherapy), genetic disorders, trauma, vitamin deficiency.

Keloid

________: overgrowth of scar tissue beyond the original wound.

Maturation

________: (weeks) tissue remodeling (collagen), removal of unneeded cells through apoptosis, reconstruction of the extracellular matrix, fibrous union.

Regeneration

________ and healing require tissue stem cells.

impairs repair

Locally ________: impaired perfusion, infection, foreign body, hematomas (blood clots), denervations, necrotic tissues, mechanical stress, type of tissue, surgical technique.

Tissue regeneration

lost tissue regrows, and occurs in tissues with high turnover (skin, gut, bone marrow), this rarely happens in organs with the exception of the kidneys and liver but this depends on the intact tissue scaffold

Healing

a combination of regeneration and scar formation (replaced with fibrous tissue)

Inflammatory Phase

(24 hrs) Removal of damaged or dead tissue; neutrophils

Proliferative Phase

(3-7 days) angiogenesis, granulation tissue formation, wound contraction; Macrophage

Maturation

(weeks) tissue remodeling (collagen), removal of unneeded cells through apoptosis, reconstruction of the extracellular matrix, fibrous union

Uncomplicated

(1st intention) edges are close, not infected, scabbing (epithelization) of the wound surface, angiogenesis, fibroblast and collagen deposition, remodeling, "good as new"

Complicated

(2nd intention) more significant gaps (infected wound, more tissue damage, foreign body), more inflammation, more granulation tissue, wound contraction becomes important mediated by myofibroblasts that contract at edges, healing is usually less than perfect and leaves a scar

Locally impairs repair

impaired perfusion, infection, foreign body, hematomas (blood clots), denervations, necrotic tissues, mechanical stress, type of tissue, surgical technique

Systematically impairs repair

age, pre-existing conditions (diabetes, malnutrition, atherosclerosis), drugs (steroids, chemotherapy), genetic disorders, trauma, vitamin deficiency

Wound Dehiscence

edges of wound separate (re-open)

Ulcer formation

wound does not heal, no scab

Hypertrophic scar

raised scar tissue that remains within the boundaries of the original wound

Keloid

overgrowth of scar tissue beyond the original wound

Aggressive desmoid tumor

(aggressive fibromatosis), benign tumors, but can grow aggressively and invade surrounding tissue, NOT cancer, and does not metastasize

Fibrosis

scarring