What is this? What will happen to this wound?

DEPARTMENT OF MEDICAL EDUCATION WOUND HEALING FAISAL GHANI SIDDIQUI MBBS; FCPS; PGDIP-BIOETHICS; MCPS-HPE PROFESSOR OF SURGERY, HEAD, SURGICAL UNIT-I, & DIRECTOR, DEPARTMENT OF MEDICAL EDUCATION LIAQUAT UNIVERSITY OF MEDICAL & HEALTH SCIENCES

PREAMBLE DEFINITION OF WOUND FACTORS THAT ADVERSELY EFFECT WOUND HEALING TYPES OF WOUND HEALING STAGES OF WOUND HEALING COMPLICATIONS OF WOUND HEALING

DEFINITION OF WOUND

WHAT IS A WOUND? Break in continuity of surface epithelium due to external agents caused by: accident | assault | surgery | self-infliction DEFINITION OF WOUND Break in continuity of lining surface epithelium (skin; oral mucosa; rectal mucosa) is defined as wound. Wound is seen in a wide variety of situations, e.g. after an accident, assault, surgery and self-inflictIion

TYPES OF WOUND TIDY WOUNDS UNTIDY WOUNDS Wounds can be: Tidy wounds

TIDY WOUND Clean wound -little or no soiling Caused by sharp objects like glass / knife Edges are not jagged Can be closed primarily Minimal scarring Tidy Wounds these are clean wounds with little or no soiling caused by sharp instruments Edges are not jagged can be closed primarily with minimal scarring

UNTIDY WOUND Dirty wound Caused by crushing injuries cannot be closed primarily Require surgical toilet and debridement Convert untidy to tidy wound Usually allowed to heal by second intention or closed primarily Untidy Wounds these are soiled wounds caused by crushing injuries. The underlying structures (nerves, vessels, etc.) are crushed to variable extent they cannot be closed primarily because in presence of foreign bodies and devitalized tissues, there are high chances of wound infection, wound dehiscence, septicemia and even death. the treatment is wound toilet and excision of all dead tissues so that it gets converted to a tidy wound. Then it can be closed primarily or allowed to heal by second intention.

TYPES OF WOUND HEALING

TYPES OF WOUND HEALING Healing by primary intention Healing by secondary intention Healing by tertiary intention

HEALING BY PRIMARY (FIRST) INTENTION Wound edges are clean-cut with minimal tissue trauma Wound edges are apposed with sutures Leaves minimal (hairline) scar Healing by primary intention is also known as healing by first intention. This occurs when the wound edges are clean cut with minimal surrounding tissue trauma. The wound edges are simply apposed to each other and leaves the best scar.

HEALING BY SECONDARY INTENTION Gaping wound Wound left open Granulation tissue fills the gap Requires Contraction / epithelization Leaves a large and ugly scar Secondary healing or healing by secondary intention occurs in wound is left open and allowed to heal by granulation (a tissue composed of capillaries, fibroblasts and inflammatory cells), contraction and epithelialization. The process leaves a large and ugly scar.

HEALING BY TERTIARY INTENTION (DELAYED PRIMARY CLOSURE) Utilized when there are high chances of wound infection Wound left open for few days Late suturing done to allow healing by primary intention Delayed primary closure or tertiary intention is utilized when there is a high probability of the wound being infected. The wound is left open for a few days and then if any infective process is resolved then the wound is closed to heal by primary intention.

PHASES OF WOUND HEALING

PHASES OF WOUND HEALING PHASE OF INFLAMMATION (Day 1-4) PHASE OF GRANULATION TISSUE (Day 5-20) PHASE OF SCAR FORMATION (Day 20 onwards) There are three phases of wound healing Phase of inflammation Phase of granulation tissue Phase of scar formation

Increased capillary permeability with escape of WBC into the wound PHASE OF INFLAMMATION (Day 1-4) Blood clot formation Increased capillary permeability with escape of WBC into the wound Neutrophils / monocytes remove dead tissue Phase of inflammation (Day 1-4) It is also known as “Lag phase”. Injury results in bleeding. Blood comes in contact with collagen tissue and activates kinins and complement cascade. Activated clotting factors and platelets aggregate leading to blood clot formation. Capillary permeability increases leading to escape of WBC into the wound. Polymorphs act as scavengers by removing dead tissue during initial 48 hrs. Then monocytes come into action and act as scavengers from 3rd to 5th day. Early inflammatory phase: platelet-enriched blood clot and dilated vessels Late inflammatory phase: increase in neutrophils and monocytes

Granulation tissue consists of fibroblasts and new capillaries PHASE OF GRANULATION TISSUE (Day 5-20) Granulation tissue consists of fibroblasts and new capillaries Fibroblasts secrete: Collagen Ground substance Protocollagen  Collagen Phase of granulation tissue (Day 5-20) The granulation tissue is rich in fibroblasts and new capillaries The fibroblasts secrete collagen and ground substance The fibroblasts produce protocollagen (immature form) that gets converted to collagen (mature form) by hydroxylation. The mature collagen fiber gives strength to the tissues. Ground substance is a thin gel like binding agent that binds collagen fibers. Granulation tissue made up of Capillary buds and fibroblasts

Remodeling continues for up to 2 years; gives strength to the scar PHASE OF SCAR FORMATION (Day 20 onwards) Remodeling: Haphazardly arranged collagen fibers are laid down in an orderly fashion along the lines of tension Remodeling continues for up to 2 years; gives strength to the scar Vascularity decreases Phase of scar formation (Day 20 onwards) Remodeling of haphazardly arranged collagen fibers takes place. New collagen fibers continues to be synthesized in an orderly fashion along lines of tension in the scar. Scar remodeling and gain in strength continues up to 2 years. Hence, scar revision for cosmetic reasons should not be done before 1 year. Vascularity becomes less and ingrowth of nerve fibers and lymphatics takes place. Mature contracted scar

MATURATION OF SCAR

FACTORS THAT ADVERSELY EFFECT WOUND HEALING

FACTORS THAT ADVERSELY AFFECT WOUND HEALING PATIENT FACTORS Old age Anaemia Jaundice Uremia Diabetes Hypoproteinemia HIV Malignancy DRUGS Steroids Chemotherapy Local irradiation WOUND FACTORS Hematoma Infection Necrotic tissue Foreign body Lack of rest to wound

COMPLICATIONS OF WOUND HEALING

COMPLICATIONS OF WOUND HEALING Wound infection Hypertrophic scar Keloid Marjolin’s ulcer Wound dehiscence COMPLICATIONS OF WOUND HEALING Wound infection Hypertrophic scar Keloid Marjolin’s ulcer

WOUND INFECTION Throbbing pain Fever Wound Red & erythematous Tense & edematous Tender out of proportion Purulent discharge Wound infection: The patient complains of throbbing pain. On examination, the wound is tense and inflamed. There may be pus discharge.

HYPERTROPHIC SCAR Red, raised, itchy and tender Excessive growth of scar tissue Scar confined to the wound Regresses after 6 months If the scar remains in remodeling stage for a longer time, it is called as hypertrophic scar. It remains red, raised, itchy and tender usually up to six months and then gradually regresses.

KELOID Raised, itchy, and red Excessive growth of scar tissue Scar spreads to adjoining tissues Continues to grow even after 1 year There is excessive growth of the scar tissue so that it spreads like a claw into adjoining normal tissues that are not affected by original wound. It has itching, erythematous and spreading margins. The keloid continues to grow even after 1 year of injury and sometimes even progress for 5-10 years.

HYPERTROPHIC SCAR VS. KELOID No relation with race More common in blacks Does not spread to normal tissues Spreads to adjoining normal tissues Subsides after 6 months Continues even after 1 year Common on flexor surfaces Common on the sternum, shoulder and back

MARJOLIN’S ULCER Squamous cell carcinoma developing in long standing scar Marjolin’s ulcer: Squamous cell carcinoma develop- ing in long standing scar is called as Marjolin’s ulcer

. . . IN SUMMARY Wound is a break in the continuity of the surface epithelium A wound can heal in 3 ways (first intention; secondary intention; tertiary intention) There are three phases of wound healing Infection, keloid, hypertrophic scar, Marjolin ulcer and wound dehiscence are some of the wound complications

Healing by secondary intention occurs when: Wound is sutured immediately B: Wound is left open C: Wound is left open and then sutured after few days

Delayed primary suturing should be done when: The wound edges are clean-cut B: When there is a large gaping wound C: When there are high chances of wound infection

Cosmetically best scars are left when healing occurs by: First intention B: Secondary intention C: Tertiary intention