Al-kindy College Of Medicine Providing Skin Cover Zuhair Bashir Kamal Professor Of Surgery Al-kindy College Of Medicine Baghdad University

The provision of skin cover could be done by Free graft Graft is removed completely from one part of the body (donor site) and grafted onto another site on the body ( recipient site) . All skin grafts must include at least a portion of the dermal layer for survival. It is separated from its blood supply & therefore depends on being placed on healthy vascular bed for its revascularization. Prior to all skin grafting ,wound swabs should be taken for culture and sensitivity to check for group A B-hemolytic streptococci.

Split Skin graft ( partial thickness or thiersch graft) Free graft Types Split Skin graft ( partial thickness or thiersch graft) It consist of epidermis & upper capillary dermis. The graft is cut with special knife which controls the skin thickness ( Dermatome). This may need either a freehand knife or a power dermatome. A thin split-skin graft is approximately 0.25 mm thickness. The usual donor sites include arm , thigh & Buttocks. The donor sites heals quickly. This site can be reused as a donor site within 7 -10 days. Infection can significantly slow healing & cause loss of deeper structures.

Cont. The main use of split skin graft is in the treatment of burn, to close defects after removal of skin tumors. Advantages of this graft: Rapid healing of the donor site. Disadvantages include post graft contractures. Lack of resistance to trauma. Absence of normal skin properties like suppleness, hair growth). The factors that affect take of the graft include: Poorly vascularized bed. Hematoma. Seroma. Infection. Movement. A bolus or tie over stent pressure dressing can be applied to prevent movement & keep all parts of the graft in contact with the bed.

Indications for skin grafting Traumatic skin loss e.g. burns. Pressure sore ( sometimes require flaps). Extensive ulcers. Following wide excision of skin tumors. Skin flap donor defects. Covering large granulating areas.

cont Skin graft may be meshed by passing though a mesher which create multiple holes so that the graft looks like a string vest. This has two advantages: Greater coverage may be obtained. Seroma or hematoma may escape through the interstices. Wide meshing allows large areas to be covered & clearly this is an advantage in a major burn. Its disadvantage: Is that the final result also resemble a string vest as the interstices will heal by epithelialization alone as they contain no dermal elements. Partial thickness skin graft if kept moist can be stored at 4 0 C for (3-4 weeks).

Full thickness graft ( wolfe graft) It consist of epidermis , dermis & therefore includes all skin elements e.g. hair follicles , sweat glands. Recipient areas : are the face & hands. Donor areas : are that of thin skin ,including supraclavicular , post auricular ,sub mammary , antecubital & inguinal regions. The donor sites require closure & if this cannot be closed primarily a split – skin graft may be required. Advantages : Full thickness skin graft include all skin elements. More supple,. Withstand trauma. Undergo the least contractures. Disadvantages: Limited donor sites. Failure of take ( full thickness skin graft has less chance of graft take than that of split thickness skin graft ). Problems in closing donor sites. Successful “ take” depends on the same factor of split-skin graft. Tie over stent dressing should be used.

Split-Thickness Skin Graft (STSG) Full Thickness Skin Graft (FTSG) Characteristics Split-Thickness Skin Graft (STSG) Full Thickness Skin Graft (FTSG) Structure 100% Epidermis & Part of the Dermis 100% Epidermis & Dermis. Also A Percentage of Fat Graft Endurance High Chance of Graft Survival Lower Chance of Graft Survival Confronting to Trauma Less Resistance More Resistance Cosmetic Appearance Poor Cosmetic Appearance. Offers Poor Color and Texture Match. This Also Does Not Prevent Contraction. Better-Quality Cosmetic Appearance. Thicker, and Prevents Contraction or Deformation. When Performed Temporarily or Permanently Performed After Excision of a Burn Injury, As Long As There Is Sufficient Blood Supply. When Aesthetic Outcome Is Important (e.g., Facial Defects). Donor Site Tissue Abdomen, Buttock, Inner or Outer Arm, Inner Forearm and Thigh Nearby Site That Offers Similar Color or Texture To The Skin Surrounding The Burned Area. Disadvantages Poor Cosmetic Appearance, a Greater Chance of Distortion or Contraction. A Higher Risk of Graft Failure. The Donor Site Requires Long-drawn-out Healing Time And Has A Greater Risk Of Deformation And Hypertrophic Scar Formation.

Pedicle Flaps These are composed of skin & subcutaneous tissues with its blood supply created on one part of the body ( Donor site ) & transferred to the other ( recipient site). The thickness of the flap renders survival impossible if transferred like graft. The survival depends on the vascular attachment to the body through out the transfer procedure. Pedicle attachment is required until a new bloody supply develop from the recipient site ,this usually takes (2-3 weeks) following which the pedicle flap is detached from the donor site.

General indications of pedicle flaps Relatively a vascular areas (exposed bones ,joint surfaces. the chest wall after extensive procedures for breast cancer. Irradiated areas. Extensive sacral pressure areas with exposed bones. Facial reconstructive surgery.

Types of pedicle flaps Random flaps A skin flaps is raised on a random blood supply (non named artery)i.e. non specific artery & a vein is included in the flap , it depend on subdermal blood vessels for its blood supply. Examples simple advancement flap , V-Y advancement flaps , Z plasty , rotational flaps ,transposition flaps. Random flaps

Axial flaps These have a known vascular supply based on named artery & vein. Flaps of greater length may be obtained if the flap being four times the length of the base of attachment. Examples : forehead flap based on superficial temporal artery , deltopectoral flap based on perforating branches of internal mammary artery, radial forearm flap based on the radial artery .

Myocutaneous flaps They consist of skin, subcutaneous tissues & underlying muscle. They are axial flaps have named vessel. They are used to cover large defects or bare bone. Examples Latissmus dorsi flap for breast reconstruction after mastectomy, Pectoralis major flaps for head & neck reconstruction.

Fasciocutaneous flaps They consist of skin, subcutaneous tissue & fascia. They are less bulky than Myocutaneous flap which is advantageous in certain conditions e.g. grafting on the back of the hand. Leaves less functional disability at the donor site. They may also be random e.g. on the lower limb.

Free flaps The blood supply of the flap is completely divided and the flap is transferred to another area of the body where revascularization is effected by micro vascular anastamosis. Free flaps may be axial. muscle, Myocutaneous or Fasciocutaneous flaps. Advantages: Single stage reconstruction. Wide choice of donor sites allowing better cosmetic results. Better tailoring to fit the defect without the constraint of pedicle. Good success results up to 95%. Disadvantages: Long operating time. The need for special equipments.

Care for the donor site It heals by primary epithelialization from remaining epithelial skin element (hair follicles, sebaceous glands & sweat glands). The thinner is the graft the more rapid is the healing. Traditional management of donor site includes: Application of paraffin gauze , cotton wool &crepe bandage for 10 days. Treat the pain at the donor site by application of local anesthetic application as it may be more painful than recipient site. More modern dressing promote more rapid healing and less pain like alginate dressing ,synthetic semi permeable membranes.

Survival of skin grafts It depends on the graft being placed on a healthy vascular bed to allow ingrowth of new vascular supply into the graft. Factors leads to failure of graft take includes: Loss of contact of graft: Tension on graft. Fluid beneath the graft. E.g. serum , blood , pus. Movement between graft and bed. Infected wounds specially by b hemolytic streptococci group A. Grafting on to an unsuitable base ; bone, cartilage, tendon, at these sites a flap procedure is required.