WOUND HEALING

WOUND HEALING

{1Wound healing is a complex method to achieve anatomical and functional integrity of disrupted tissue by various components like neutrophils, macrophages, lymphocytes, fibroblasts, collagen ;in an organized staged pathways as follows:INTRODUCTION2

3PHASES OF CUTANEOUS WOUND HEALING4Injury results in the release of mediators of inflammation, mainly histamine from platelets, mast cells and granulocytes. This results in increased capillary permeability.

Later kinins and prostaglandins act and they play a chemotactic role for white cells and fibroblasts.

In the first 48 hours. PMNs dominate. They play the role of scavengers by removing the dead and necrotic tissue.

INFLAMMATORY PHASE(lag phase)[48 hours]5Between 3rd and 5th day PMNs diminish and monocytes increase. They are the specialized scavengers.

By 5th or 6th day, fibroblasts appear, proliferate and eventually give rise to protocollagen converting to collagen

Protocollagen----------------collagen

PROLIFERATIVE PHASE(collagen phase)[3rd to 6th day]Protocollagen hydroxylaseO2,ascorbic acid,Fe2+6Fibroplasia along with capillary budding gives rise to granulation tissue.

Secretion of ground substance- mucopolysaccharides by fibroblasts take place. These are called proteoglycans, they help in binding collagen fibers. Thus, wound is fibre+gel+fluid system

Epithelialization occurs mainly from the edges of the wound by a process of cell migration and cell multiplication. This is mainly bought by marginal basal cells. Thus, within 48 hrs., the entire wound is re-epithelialized.

Slowly surface cells get keratinized.7It is brought about by specialized fibroblasts. Because of their contractile elements, they are called myofibroblasts.

It is the natures way of reducing the size of defect, thereby helping the wound healing.

Wound contraction readily occurs when there is loose skin as in back and gluteal region. Skin contraction is greatly reduced when it occurs over tibia or malleolar surface.REMODELLING PHASE (maturation)[4th to 14th day]8Following changes take place during scar formation:

PHASE OF SCAR FORMATIONFibroplasia and laying of collagen is increased

Vascularity becomes less

Epithelialization continues

Ingrowth of lymphatics and nerve fibers takes place

Remodeling of collagen takes place with cicatrisation, resulting in scar.

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PHASES OF DEEP WOUND HEALING10FACTORS AFFECTING WOUND HEALINGlocal factors:11General factors:12

SKIN GRAFTING

13Skin grafting is the transfer of skin from one area(donor area) to the required defective area(recipient area).It is an autograft.

Skin grafting is the commonest method of achieving wound cover.DEFINITION:TYPES:14

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16It is removal of full epidermis + part of the dermis from the donor area. It may be:

All depends on the amount of thickness of dermis taken.PARTIAL THICKNESS GRAFT(split-thickness skin graft-SSG)[thiersch graft]17

18Well granulated ulcer.Clean wound or defect which can not be apposedAfter surgery to cover and close the defect created. E.g.: after wide excision in malignancy, after mastectomy, after wide excision in SCC.Indications of SSG:Prerequisite for SSG:Contraindication for SSG:SSG cannot be done over bone, tendon, cartilage, joint.19 DONOR AREA: commonly thigh, occasionally arm, leg, forearm. Knife: Humbys knife Blade: Eschmann blade, downs blade Using humbys knife graft is taken, punctate bleeding is observed which says that proper graft has been obtained.Technique of SSG: RECIPIENT AREA is scraped well and the graft is placed after making window cuts in the graft to prevent the development of seroma. Graft is fixed and tie-over dressing is placed. If graft is placed near the joint, then the part is immobilized to prevent friction which may separate the graft. On 5th day, dressing is opened and observed for graft take up. Mercuro chrome is applied over the recipient margin to promote epithelialisation. 20Stage of plasmatic imbibition: Thin uniform, layer of plasma forms between recipient bed and graft.Stage of inosculation: Linking of host and graft which is temporary.Stage of neovascularisation: New capillaries proliferate into graft from the recipient bed which attains circulation later.

Note:Graft is stored at low temperature of 4oC for not more than 21 days. Stages of Graft Intake:21Contracture of graft. Two types:Primary contracture means SSG contracts significantly once graft is taken from donor area (20-30%). Thicker the graft more the primary contracture.Secondary contracture occurs after graft has taken upto recipient bed during healing period, due to fibrosis. Thinner the graft more the secondary contracture. Seroma and haematoma formation will prevent graft take up.Infection.Loss of hair growth, blunting of sensation.Dry scaling of skin due to nonfunctioning of sebaceous glands. So after healing, oil (coconut oil) should be applied over the area.Graft failure. Disadvantages of SSG:22Technically easier. Wide area of recipient can be covered. To cover large area like burns wound, graft size is increased by passing the graft through a Meshar which gives multiple openings to the graft, which can be stretched on the wider area like a net. It can cause expansion upto 6 times. Graft take up is better.Donor area heals on its own.Mercurochrome/merbromin is used as a local applicant to the edge of the grafted area (SSG) and small raw areas to promote epthilialisation. It is applied once a day.Advantages of SSG:23FULL THICKNESS GRAFT(Wolfe graft)

24It includes both dermis and epidermis.It is used over the face, eyelid, hands, fingers and over the joints.It is removed using scalpel blade. Underlying fat should be cleared off properly.Deeper raw donor area is closed by primary suturing. If large area of graft is taken, then the donor area has to be covered with SSG which is a disadvantage in full thickness graft.25Color match is good. Especially for faceNo contracture (unlike in SSG)Sensation , functions of sebaceous glands, hair follicles are retained better compared to SSG.Functional and cosmetic results are better.Advantages of Wolfe graft:Disadvantages of Wolfe graft:It can be used only for small areas.Wider donor area has to be covered with SSG to close the defect.Can not be used to cover ulcers.

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TISSUE FLAPS27Flap is a block of tissue transferred from donor to recipient area along with its vascularity.

INDICATIONS FOR FLAP SURGERY:To cover defects/wounds where free skin graft cannot be used. E.g. : exposed bare bones, bare tendons, bare cartilage.

Wounds with exposed joints, exposed major vessels and nerves.

Implant exposure following orthopedic procedures.

In wounds with soft tissue loss, where future reconstructive surgery is contemplated.

Defects which need better contour to improve cosmesis.

Breast reconstruction following mastectomy

28TYPES OF FLAPS:

29Anatomical types depending upon the types of tissues in flap:3031

Z plasty

Transposition flaps32

AMPUTATIONS OF LOWER LIMB

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SYMESCHOPARTLISFRANCTRANSMETATARSAL35

RAY AMPUTATION: amputation of toe with head of metatarsal.

TRANSMETATARSAL AMPUTATION [Gilles] : amputation is done proximal to neck of the metatarsals, distal to the base.

LISFRANC AMPUTATION [Tarsometatarsal ] : tarsometatarsal joint is disarticulated with a long volar flap. It needs a surgical boot. But there is inevitable development of equinovarus deformity.Ray amputation

36CHOPARTS AMPUTATION [Midtarsal amputation]: talonavicular and calcanaeo-cuboid joints are disarticulated. Tibialis anterior muscle is sutured to drilled tallus bone. A long volar flap is used.Contraindication: ischemic feet in atherosclerosisDisadvantages : very unstable amputation, because most tendons supporting foot will be removed.

SYMES AMPUTATION : The tibia and fibula are divided at or immediately above the level of ankle joint and their ends are covered with a single flap obtained from heel.End of stump is at a height of about 6-8 cm from the ground.50% people can walk on stump without prosthesis.Pergoffs modification of symes : retains a small portion of calcaneum in the flap obtained from heel.

37BELOW KNEE AMPUTATION [Bourges amputation] : operation of choice when it is not possible to preserve the foot or heel.

AMPUTATIONS THROUGH THIGH : Ideal length of tibial stump is 14 cm.Minimum length required to fit an artificial leg is 8 cm.Stump is covered by creating long posterior flap.Commonly done in patients who are in severe sepsis involving the leg with uncontrolled diabetes and life is in danger.POP cast should be put to be present contractures.Ideal length is 25-30 cm as measured from tip of trochanter.It is done when it is not possible to save at lest 8 cm of tibia as in some cases of diabetes or spreading infections of the leg and when muscles involved are not bleeding at surgery.Equal flaps are raised anterior and posterior.Disadvantages to this are difficult rehabilitation, prosthesis fitting not good.38HIP DISARTICULATION :

HINDQUARTER AMPUTATION [ hemipelvectomy] : When it is not possible to get minimum of 10 cm length of stump of the femur, hip disarticulation is done. This situation can occur in trauma or malignancies is to get a wide clearance. E.g. : sarcomas or in cases of malignant melanomasUsually a single posterior flap is raised solcums approach.Anterior approach can also be used (2nd option )- boyds approachIn this amputation one side of pelvis with innominate bone, pubis, muscles and vessels are removed.Indications are trauma and tumor.Large posterior flap based on gluteal artery is used.Originally common iliac artery used to be ligated. However, now the branches or external and internal iliac artery are ligated/39THANKYOU40