wound healing and the problem wound
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Wound Healing and The Problem Wound. Manal E. Alotaibi. Contents. Definition Types of wound closure Phases of Wound Healing Impaired Wound Healing: Local factors &systemic factors Excessive Healing. Definition . - PowerPoint PPT PresentationTRANSCRIPT
Wound Healing and The Problem Wound
Manal E. Alotaibi
Contents• Definition • Types of wound closure• Phases of Wound Healing• Impaired Wound Healing: Local
factors &systemic factors• Excessive Healing
Definition
A complex integrated sequence of cellular, physiologic, and biochemical events initiated by the stimulus of injury to tissue
Types of wound closurePrimary closureAll Layers are closed.
Approximation of acutely disrupted tissue with sutures, staples or tape.
The incision that heals by first intention does so in a minimum amount of time.
with no separation of the wound edges, and with minimal scar formation.
Primary closure
Delayed primary closureApproximation of wound margin
delayed for several days.Prevents wound infection in cases of
contamination/foreign bodies/tissue trauma.
Less bacterial colonization in open wound .
Normal healing progress occurs.Left open initially.Edges approximated 4-6 days later .
Delayed primary closure
Secondary wound closureOpen wound margins approximate by
biologic contraction Surfaces not approximatedDefect filled by granulationDeep layers are closed but superficial
layers are left to heal from the inside out.
Healing by second is appropriate in cases of infection, excessive trauma, tissue loss, or imprecise approximation of tissue.
Secondary closure
Secondary closure
Secondary closure
WOUND HEALING PHASES
Inflammatory
phase
Proliferative phase
Maturational
phase
Inflammatory PhaseHemostasis and InflammationKey components of this phase are
increased vascular permeability, and cellular recruitment
Days 4 - 6 Exposed collagen activates clotting
cascade and inflammatory phaseFibrin clot = scaffolding and concentrate
cytokines and growth factors
At the initial time of
tissue disruption,
platelets release
coagulation factors
and cytokines to
initiate the healing
process
Within the first day following tissue
injury, neutrophils attatch to
surrounding vessel walls and then move through the vessel walls to migrate to
the wound site
Inflammatory Phase
Proliferative phase
1. angiogenesis
2. fibroplasia
3. Epithelization. Production of collagen is hallmark 7 days to 6 weeks
Angiogenesis
The process of new blood vessel formation to support a healing wound environment .
tissue hypoxia – major stimulusTNF-α, heparin, VEGF, FGF-1, FGF-
2
The fibroplasia phase is characterized by movement of wound macrophages into the site of injury, which in turn attract fibroblasts. The fibroblasts then repair the site by producing new connective tissue matrix.
Wound ContractionActual contraction with pulling of edges
toward center making wounds smallerMyofibroblast: contractile propertiesSurrounding skin stretched, thinnedOriginal dermal thickness maintainedNo hair follicles, sweat glands
Epithelialization Basal epithelial cells
at the wound margin flatten (mobilize) and migrate into the open wound
Basal cells at margin multiply (mitosis) in horizontal direction
Basal cells behind margin undergo vertical growth (differentiation)
Epithelialization/Contraction
Epithelialization
Proliferative Phase
Maturation Phase
Day 8 through yearsType III replaced by type IWound may increase in strength for up to 2
years after injuryCollagen organizationCross linking of collagen
Maturation Phase
FACTORS AFFECTING WOUND HEALING
Systemic factorsThe most common nonhealing wounds affecting the lower
extremities are associated with peripheral artery disease, diabetes and chronic venous insufficiency.
Peripheral artery disease Diabetes Chronic venous insufficiency Aging Sickle cell disease Cancer therapy Spinal cord disease and immobilization Malnutrition Smoking .
Excessive Healing
hypertrophy and keloid formation are an overactive response to the natural process of wound healing.
Hypertrophic Scars
raised and thickened.does not extend beyond the boundary of the
incision/scar.this process is exacerbated by tension lines on the
areaof surgery. incisions over the knee and elbow have a higher
incidence of hypertrophic reaction.Treatment: nearly all hypertrophic scars undergo a
degree of spontaneous resolvement. if still present after six months, surgical excision is indicated.
Hypertrophic Scars
KeloidsRaised and thickened. This process extends beyond the boundary of
the incision.Continues weeks to months past the initial
insult.Higher incidence in African Americans.Treatment: Pressure applied early may
decrease the extent of keloid formation.corticosteroid injection may be helpful.Excision with intramarginal borders is
reserved for intractable keloids.
Keloids
summary
A wound is a disruption of the normal structure and function of the epidermis.
Wounds may be caused by a variety of mechanisms including acute injury (abrasion, puncture, crush), surgery or other factors that cause breakdown of previously intact skin (eg, ischemia, pressure).
After hemostasis has been achieved, acute wounds normally heal in an efficient manner characterized by four overlapping phases: inflammation, epithelialization, fibroplasia, and maturation.
Many disease states alter the process of wound healing, the most common of which are peripheral artery disease, diabetes, and chronic venous disease.
References UpToDateWound-Healing-student-lecture-
May-2011, Abigail E. Chaffin, M.D. Assistant Professor of Plastic Surgery;Tulane University School of Medicine.
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