Different technique in skin grafting

various techniques in skin grafting

1. TECHNIQUES IN SKIN GRAFTING DR.Punithavasanthan.B FNB(Hand and microsurgery) SKIMS-Srinagar

2. Meek micrografting One of the techniques to increase the surface area. Introduced by by Cicero Parker Meek in 1958. Later it was modified In 1993, the modified Meek technique was first published by Kreis et al.

3. concepts to his creation were split-thickness skin grows from the periphery outward the smaller the skin piece is, the greater is its surface in relation to its volume the ideal for re- epithelializing a denuded area in the quickest manner is to provide the greatest possible growing margin to the area.

4. In 1993, the modified Meek technique was first published by Kreis et al.with a special glue spray TECHNIQUE Cork pieces (42 × 42 mm) from the Meek system ( Humeca , Enschede , The Netherlands)

5. The cutting machine contains 13 parallel round blades spaced 3 mm apart from each other . blades incise split skin autograft into 14 strips 3 mm 14* 14=196 PIECES ARE MADE

6. The epidermal upper surface of the STSG is then sprayed with an adhesive dressing spray and allowed to dry for 5–10 minutes After the cork is pressed onto a prefolded polyamide gauze on an aluminium foil backing into 14x14 square pleats . The gauze is pulled out on all four sides, until the pleats become entirely unfolded. Finally, the aluminium backing is peeled off, leaving the expanded gauze with the separated autograft islands ready for grafting. After trimming the margins, the gauze is applied, graft side down, to the wound bed and secured with surgical staples

7. Patient selection. micrografting is indicated for use in major burns (>30% TBSA), and where there are insufficient donor sites able to provide the required amount of skin graft Poor wound beds - Micrografting has higher success on poor (infected and/ or with poor vascular supply) wound beds due to low metabolic demands and greater skin coverage expansion ratio

8. Mesh vs Meek It is particularly important, when grafting large surface areas, to accurately estimate the required donor site based on the technique used: planning an operation with a 1:3, a 310cm2 STSG harvested can achieve coverage of up to 493cm2 with a mesh graft or 927cm2 with a micrograft mesher . The Meek technique (with true expansion ratios from 1:3 to 1:9) requires only about half of the graft surface compared with the mesh graft method.

9. When comparing the ‘mesh’ with ‘Meek’ group, the ‘Meek’ group had much fewer surgeries (10 versus 19.75), a shorter average length of hospital stay (51 days versus 120.5 days), and less allograft used for each TBSA% burns (115.7cm2 versus 356.5cm2) with overall lower patient costs. Complete re- epithelialisation with the Meek procedure was seen 7–10 days following the graft: 1:4, 2–3 weeks: 1:6, one month: 1:9. Meek micrografting history, indications, technique, physiology and experience: a review article - JOURNAL OF WOUND CARE WUWHS SUPPL EMENT, VOL 2 7 , NO 2 , F EBRUARY 2 0 1 8

10. ADVANTAGES pre-folded gauzes are now manufactured with expansion ratios 1:3, 1:4, 1:6 and 1:9.  Minimal donor sites  Graft islands are close together in a regular pattern, resulting in fast and uniform epithelialization  Failure of a few islands does not affect the overall graft take  Cosmetic results are comparable with meshgrafts of a lower expansion Grafts adhere to a fabric and are therefore very easy to manipulate when applying them to the wound

11. Do’s and don’ts in MEEK Micrografting Don’t put any oil or other fatty substance on the patients skin when harvesting the graft. This prevents the glue from sticking the graft to the gauze. Use saline solution instead. Don’t harvest a graft so thick that fatty tissue is visible at the dermal side. fatty tissue will cause the graft to slip on the cork plate at cutting. (thickness approx. 0.3 mm). Place the graft on the cork plate dermal side down. Don’t spray too much glue on the graft. Spray from a distance of about 20 cm.

12. Micrograft -allograft sandwich method Using a fine forceps, individual micrograft is picked up from the cork bases and lined it onto the allografts sheets.(10cm 8cm ) Micrografts are carefully spaced out 1cm apart, similarly with the dermal surface facing upwards The allografts are fenestrated with a surgical blade to allow seepage of plasma exudate after grafting

13. When the recipient site is ready for grafting, a thin layer of slow-acting fibrin sealant ( Tissel , Baxter, USA) is sprayed onto the grafts and recipient wound

14. By Day 5, the dressing is taken down for inspection of the wound By Week 2 to 3, the adherent allograft is carefully removed with preservation of micrograft islands.

15. The main advantage of allograft is the ability to act as a temporary skin cover. This helps to suppress bacterial proliferation, control exudates, and promote epithelisation of the wound . Smaller allograft(10 * 8 cm) sheets also allow plasma exudates or blood to seep out, preventing hematoma formation.

16. Chinese Intermingled Technique (Sandwich technique)  wounds are covered with freshly taken allograft skin, from which little squares of approximately 0.5 cm 2  are cut out, with a distance of 1-2 cm between them. One or two days after this transplantation the "holes" are filled with autologous split-thickness skin islands of the same size. From these autogeneic islands, cells grow out radially and rapidly substitute the epidermal defects,

17. Only the epidermis and skin adnexa , are rejected over a period of 15-25 days, because of their significantly higher antigenicity , unlike that of the dermal connective tissue. The remnants of the allodermis seem to be gradually replaced. allodermis serves as a matrix for the outgrowing epithelial cells.

18. the rejection of the allograft is avoided by the fast overgrowing of the autogeneic epidermis.  Intermingled skin grafting obtains better effects in elasticity of the reconditioned skin, as the elastic fibres of the allodermis survive, resulting in fewer contractures

19. The sandwich-overlay technique

20. Autograft meshed into 1:6,1:8,1:9, Allograft meshed 1:3 Allograft taken from recently deceased relative or parent Fresh allograft is better than stored allograft

21. The Pinch grafting Reverdin in 1 8 6 9 . harvesting small pieces of partial thickness skin by shaving off the surface of tissue pinched between the thumb and forefinger. became known as "pinch" grafts

22. Patient selection chronic venous ulcers of the lower extremity, ulcers resulting from chronic radiodermatitis , decubitus ulcers, and small chronic traumatic wounds or burns Advantages minimal blood loss and little postoperative morbidity. the success rate is high even in local wound infection and poor circulation wound bed.

23. Disadvantages creation of a cobblestone-like, irregular surface.“{do not typically provide a good cosmetic match with the surrounding skin," but rather are used to provide a functional result,} limited in the size of wounds that can be treated because of the time required to perform this procedure for large wounds.

24. The grafts are placed within the ulcer bed with 1 to 2 mm of space between one another and also from the margins of the wound.

25. Postage stamp skin grafts STSG is cut into 1 cm 1 cm squares

26. The regularly distributed and correctly oriented skin islands are able to achieve wound coverage with limited donor skin. The greatest expansion ratio is 1:9. This technique provides su cient expansion ratio, enabling surgeons to graft patients with burns of up to 75% TBSA using only one donor site practical and reliable method in dealing with extensive burn wounds. The average postage skin stamp take rate was about 90%.

27. Microscopic Diced Graft

28. Micrograft is incorporated into the granulation tissue with a distance of 1 cm each

29. The reason that the orientation of the minced skin did not matter is because the skin pieces embedded in granulation tissue are small enough to have their dermal appendages in contact with the wound. The minced skin grafts that are oriented in a lateral or downward direction would first develop epidermal cysts or columns and then extend upward to cover the wound surface or meet with the epidermal layer from other microskin grafts.

30. Cultured epithelial autograft (CEA) The ability to grow keratinocytes in vitro and generate cohesive sheets of stratified epithelium which maintains the characteristics of authentic epidermis was developed by Rheinwald and Green in 1975 .

31. The ‘‘feeder layer’’ supports optimal clonal expansion of proliferative epithelial cells and promotes keratinocyte growth. Under these conditions, some keratinocyte cells initiate growing colonies and after 3–4 weeks the CEA sheets are 8–10 cells thick. Within 3 or 4 weeks, a 3-cm2 biopsy can be expanded more than 5000–10,000-fold to yield enough skin to cover the body surface of an adult

32. Ultimately, grafted cultured keratinocytes generate a normal epidermis over many years and favor the regeneration of a superficial dermis indicating that stem cells are permanently established and that epidermal renewal proceeds normally

33. Disadvantages delays in obtaining the grafts, their variable take rate, their sensitivity to infection and their high cost Another disadvantage of CEA is its extreme friability. The actual placement of the cultured autograft on an excised bed requires meticulous attention to detail. The high vulnerability of the cultured cell sheet to bacterial proteasesand cytotoxins during the first weeks of maturation and attachment

34. Chronic granulating wounds have a 15% take, freshly excised or early granulating wounds have a 28–47% take, and wounds dressed with cadaveric skin before grafting have a 45–75% take

35. Spray grafting Stsg 2 cm-by-2cm, and from 0.15 mm to 0.50 mm thick. mixed with a enzyme solution containing trypsin that disaggregates, or separates, the cells from one another. the skin sample is removed and scraped with a scalpel to create a “plume of cells,” which are added to a buffer solution. Finally, the cells are aspirated and filtered to create a suspension called the Regenerative Epithelial Suspension Used independently to treat partial-thickness burns, or in combination with skin grafting and/or a dermal regenerative template to treat deep dermal or full- thicknessburns

36. Skin substitutes and Skin grafting

37. Biobrane and Integra [synthetic] Biobrane is made of a nylon mesh mimicking as a “dermis” and a silicone membrane as an “epidermis” implanted in porcine collagen. Integra consists of a silicone membrane as an epidermal layer and dermal layer made of bovine collagen and shark chondroitin-6-sulphate glycosaminoglycan .

38. Indications and functional outcome of the use of integra dermal regeneration template for the management of traumatic soft tissue defects on dorsal hand, fingers and thumb - Hussein Choughri et al, Archives of Orthopaedic and Trauma Surgery https://doi.org/10.1007/s00402-020-03615 15 dorsal defects of hand

39. Surgeries performed simultaneous with Integra placement included extensor tendon injury repairs in eight cases, osteosynthesis of metacarpal and/or phalanx fractures in five cases, arthrodesis of the thumb interphalangeal (IP) joint in one case and DIP joints of the fingers in two cases, and revascularization of a finger in one case

40. IDRT is a safe and effective alternative primary or secondary (posttraumatic or post-infectious) treatment in patients with a defect that would require reconstruction with a flap, including elderly patients with comorbidities deep partial thickness and full-thickness burn wounds, full-thickness skin defects of different aetiologies , chronic wounds, and in soft tissue defects

41. Integra/host tissue integration, characterised by changes in colour . The change from red to pink on day 7 reflects fibroblast migration; the change from pink to peach on day 14 reflects neovascularization while that from peach to vanilla between days 21 and 28 reflects replacement of the dermal matrix collagen by host collagen.

42. DNA analysis of wounds after the application of non- autologous skin substitutes shows almost complete disappearance of the grafted cells after two months. The goal of these dermal grafts is to provide a temporary biologic dressing in order to stimulate the healing process. They are placed over the wound, extending slightly onto normal skin, and then bolstered into place.

43. Biobrane -Superficial second-degree burns temporary covering Integra-Third-degree burns combined with thin STSG. Two-stage procedure

44. Biobrane gloves are available to treat partial-thickness hand burns that have been debrided of all nonviable tissue. Biobrane decreases pain due to its semiocclusive nature, provides direct visualization of the wound bed due to its transparency, and allows improved range of motion as it stretches with movement. semiocclusive dressing- fluid or hematomas accumulate beneath the fabric, infections may occur.

45. On reepithelialization of the skin, the Biobrane acquires an opaque appearance, indicating the product is ready for removal. Indications (1) for dressing superficial partial thickness burns, particularly of the face,hand . (2) after tangential excision of deep dermal and fullthickness burns, when cadaver skin or autograft is unavailable or insufficient, (3) for graft reduction, that is, in areas where depth is equivocal, the use of Biobrane may reduce the necessity for skin grafting.

46. Matriderm The dermal matrix Matriderm is a highly porous, membrane consisting of a native bovine type I, II and V collagen with elastin-hydrolysate . It is available in sheets of 1mm and 2 mm thickness. deep partial thickness and full-thickness.

47. The native collagen fibres form a scaffold that directs fibroblasts toward dermal regeneration. The presence of elastin diminishes the formation of granulation tissue in an early phase of wound healing. By diminishing the expression of myofibroblasts , elastin reduces wound contraction

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