DefinitionThis section has been translated automatically.
Free skin graft from epidermis and upper corium layer.
General informationThis section has been translated automatically.
- Harvesting technique and characteristics: The thickness of the split skin is 0.2-0.8 mm. Thin, medium and thick flaps of split skin can be removed according to the proportion of dermis. Electrodermatomes are used for removal. Flap thickness and width are variably adjustable. Manual dermatomes (e.g. Thiersch knife, Padgett drum dermatome, Blair-Humby dermatome) are not very suitable, especially for larger removal sites. Before the procedure, both the donor region and the dermatome knife are sprayed with a silicone lubricant spray. After even tensioning of the donor area by an assistant, the split skin collection is performed with the dermatome. Following careful haemostasis and fitting of the graft into the defect to be covered, the donor tissue is cut to fit and then fixed in the recipient bed using sutures, staples and/or fibrin glue.
- The varying thickness of the split skin is decisive for the subsequent pigmentation structure and functional quality. Thin transplants, such as the so-called Thiersch flaps (0.2-0.4 mm) are the least demanding on the recipient bed and leave hardly any scars at the site of removal. However, they have the disadvantage of being most subject to secondary shrinkage. Therefore, they are mainly used at sites of low mobility, e.g. lower legs (Fig. 2 a, b). Medium-thickness (0.4-0.6 mm) split-thickness skin grafts are used most frequently because they hardly develop secondary shrinkage. However, they may leave hypertrophic scars and keloid formation at the donor site (Fig. 3). Three-quarter flaps (0.6-0.8 mm) provide the best functional and cosmetic results, but they are the most demanding in terms of blood supply to the recipient area. Immobilization as well as minimization of tension imposed on the graft must be ensured.
- As a contrast between the healed graft and the surrounding skin, a so-called patch phenomenon often develops, in which there is a pigmentation difference to the surrounding area of the recipient bed (Fig. 4). For this cosmetically relevant reason, the split-thickness skin graft should be used for functional rather than aesthetic restoration.
- When using the mesh or mesh flap technique ( mesh graft grafts), an incision pattern is applied to a split skin flap by the cutting roller of a mesh graft dermatome. In this way a flap enlargement can be achieved and in addition the possibility of drainage is given. After split skin harvesting, sebaceous and sweat glands remain at the donor site and act as a source of subsequent re-epithelialization (Fig. 5).
- Split skin grafts are superior to mesh grafts both functionally and cosmetologically. Mesh graft transplantation appears to be justified only in exceptional cases, especially in larger leg ulcers and burns, e.g. in areas of the body that cannot be immobilized or if there is an increased risk of postoperative bleeding.
- Suitable donor regions are the ventrolateral proximal thighs (Fig. 6), the inner and outer sides of the upper arms, and the gluteal region.
- Tissues without or with minimal nutritive supply, such as cartilage, tendons, bones, which are only able to form granulation tissue under special conditions, are not suitable for free skin grafts. Traumatically damaged tissue and fibrous indurated layers due to radiation damage or chronic ulceration are also unsuitable for transplantation and should be removed down to vital structures to create a wound bed of granulation tissue suitable for transplantation.
- Indications: Ulcus cruris, large defects of trunk and extremities, especially after wound conditioning, severe burns and scalds requiring surgery with pathological recapillarization time.
Complication(s)This section has been translated automatically.
- Early complications: After free split skin transplantation, the graft may lift off the base due to the formation of a haematoma and fall victim to total necrosis. The risk of hematoma can be minimized by exact hemostasis, compression and incision of the split skin. Seroma must be expected if the defect to be covered is located close to the lymph node. Lymphorrhoea, which can last for weeks under certain circumstances, must be thoroughly drained and compressed from the outside.
- General: Shrinkage of the graft (up to 20% of the total surface); long lasting pain at the donor site, hyperpigmentation.
LiteratureThis section has been translated automatically.
- Hamm H, Wegmann K, Bröcker EB (1994) Comparative functional and cosmetic aspects of split skin and mesh split skin (mesh graft) transplantation. In: Mahrle G, Schulze HJ, Krieg T (Hrsg) Wound healing - wound closure. Progress in surgical and oncological dermatology, Vol. 8 Springer, Berlin
- Kaufmann R, Podda M, Landes E (2005) Dermatological operations. Colour atlas and textbook on skin surgery. Thieme, Stuttgart New York
- Rudoph R, Fisher JC, Ninnemann JL (1989) Skin grafts. Thieme, Stuttgart
- Salasche SJ, Feldman BD (1987) Skin grafting: perioperative technique and management. J Dermatol Surg Oncol 13: 973-978
- Steiner A, Diem E (1988) Operative dermatology, methods of defect closure I. Literature and practice 2: 117-119
- Winter H (1994) Conditioning of defect wounds in operative dermatology. close derm 6: 632-634