1. What is this?
What will happen to this wound?

3. 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

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

5. DEFINITION OF WOUND

6. 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

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

8. 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

9. 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.

10. TYPES OF WOUND HEALING

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

12. 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.

14. 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.

16. 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.

17. PHASES OF WOUND HEALING

18. 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

19. 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

20. 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

21. 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

22. MATURATION OF SCAR

23. FACTORS THAT ADVERSELY EFFECT WOUND HEALING

24. 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

25. COMPLICATIONS OF WOUND HEALING

26. 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

27. 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.

28. 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.

29. 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.

30. 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

31. 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

32. . . . 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

33. 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

34. 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

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