Prevention of deformities using thick split-thickness skin grafts to repair infected wounds. Report of 22 cases

Previously, split-thickness skin graft was used as coverage for the infected wounds in special site. Because severe contracture and deformities occurred later due to thin skin graft, further plastic surgery was needed, yet the results still were unsatisfactory in some cases. In 22 patients, large pieces of thick split-thickness graft were used to cover the excised granulation wounds where the plate of collagen fibers were relaxed. All the grafts were 100% taken. The functions and appearances were satisfied after one year follow-up. The authors recommended that thick split-thickness skin graft possesses the properties of full-thickness skin graft. It will be taken well, if the infection of wound can be controlled and adequate blood supply of wound is provided.     

Vaginal construction with skin grafts and vacuum-assisted closure.

Probably the most common method of constructing a vagina in patients with the Mayer-Rokitansky-Küster syndrome is the technique popularised by McIndoe and Banister in 1938. A cavity is created between the rectum and urethra-bladder complex and is lined with split-thickness skin grafts. One of the disadvantages of using split-thickness skin grafts is the incidence of late contraction of the neovagina. To avoid this problem full-thickness skin grafts have been used, but their take is less reliable. A new technique to improve the take of skin grafts is the VAC-system (vacuum assisted closure, KCI) which has proved to be particularly valuable in grafting difficult anatomical sites. We have used the VAC-system in the construction of a vagina in one case with split-thickness skin grafts and in two cases with full-thickness skin grafts. In all three cases the take was excellent with little discomfort for the patients. It was not necessary to stent the neovagina in the postoperative period and coitus was possible within a month of operation.     

Long-term results of syndactyly correction: full-thickness versus split-thickness skin grafts

In order to compare the long-term results of full-thickness and split-thickness skin grafts after the correction of congenital syndactyly, 27 patients have been investigated after an average follow-up of 21 years. Post-operative functional and cosmetic results have been assessed by patient records, questionnaires and physical examination. The webs that had received split-thickness grafts showed more flexion and extension lags and the overall spreading of the operated fingers was significantly decreased compared to the control fingers. On the other hand, more re-operations because of web creep had to be performed after full-thickness grafts. Hyperpigmentation and hair growth in the grafts was found in most of the full-thickness grafts, while breakdown of the graft was found in some of the split-thickness grafts. Therefore, based on the results of this study, either full- or split-thickness skin grafts can be used when treating of congenital syndactyly.     

Promising therapy for congenital giant pigmented nevi using acellular autograft nevi-dermal matrix.

As promising new therapy for congenital giant pigmented nevi, the authors investigated the potential use of an acellular autograft nevi-dermal matrix in combination with a split-thickness skin graft. To address whether the processed acellular nevi-dermal matrix from frozen skin could be reconstituted as a viable dermal base, the authors grafted it onto full-thickness skin defects in nude rats. Fibroblast infiltration and neovascularization into the acellular nevi-dermal matrix were observed. However, because the disappearance of the residual melanotic granules of the grafted dermis took 16 weeks, the authors excised with scissors the superficial layer of the acellular nevi-dermal matrix containing a large quantity of melanin. The appearance after using this method was relatively superior even compared with the full-thickness skin graft. The success of their experimental animal model using the acellular nevi-dermal matrix covered with split-thickness skin grafts confirms the potential value for the clinical application of this treatment for congenital giant nevi.     

采用瘤体表面中厚皮片修复巨大皮肤良性肿瘤切除后创面

目的:总结利用巨大皮肤良性肿瘤表面皮肤加工的中厚皮片修复其瘤体切除后创面的经验。方法:对1999年1月～2010年12月,我科收治的37例巨大皮肤良性肿瘤患者,在实施病灶切除后,利用鼓式取皮机的反鼓取皮技术,将瘤体表面皮肤加工成中厚皮片修复肿瘤切除后创面。结果:10例皮片成活率95%～100%,27例成活率为70%～90%,其中17例经换药愈合,10例经二次手术补充植皮愈合。所有病例术区外形良好,功能恢复满意,部分病例局部有少量瘢痕形成。结论:与取自正常皮肤的中厚皮片相比,此类皮片移植成活率稍低,但对于瘤体巨大,且位于非功能部位或相对隐蔽部位者,也不失为一种可供选择的修复方法。     

New grafts for old? A review of alternatives to autologous skin.

Immediate resurfacing of skin defects is a challenging prospect, especially in patients with extensive full-thickness burns. Currently, split-thickness autografts offer the best form of wound coverage, but limited donor sites and their associated morbidity have prompted the search for alternatives. The application of allogeneic skin is restricted by availability and the risk of transmission of infection, whilst synthetic skin substitutes are simply expensive dressings. The problems of limited expansion may be overcome by culturing keratinocytes in vitro. Unlike autologous cells, allogeneic keratinocytes are available immediately, although they survive for less than a week when applied to full-thickness skin defects. Moreover, the absence of a dermal component in these grafts predisposes to instability and contracture. A cross-linked collagen and glycosaminoglycan dermal substitute, covered with thin split-skin grafts or cultured autologous keratinocytes, shows promise in burns patients. An alternative is a collagen matrix populated by allogeneic fibroblasts and overlaid with cultured autologous or allogeneic keratinocytes. The clinical application of cultured grafts remains imperfect but offers the prospect of immediate coverage and massive expansion.     

Allogeneic skin substitutes applied to burns patients

Early re-surfacing of burn wounds remains the ideal but is limited by the availability of skin graft donor sites. Cultured grafts overcome these problems and autologous keratinocytes can be grown in culture and placed on a dermal substitute, but this results in delay and requires two operations. We developed an organotypic skin substitute, which achieves cover in one procedure, and have previously found allogeneic cell survival up to 2.5 years after grafting onto clean elective wounds (tattoo removal). Here, we report a short series using the same model applied to burns patients with less than 20% total body surface area affected. The skin substitutes consisted of allogeneic dermal fibroblasts embedded in a collagen gel overlain with allogeneic epidermal keratinocytes, and were grafted to patients with tangentially excised burns. A side-by-side comparison with meshed split-thickness autografts was performed. No grafts became infected. The allogeneic skin substitute showed little effective take at 1 week, and by 2 weeks only small islands of keratinocytes survived. These sites were subsequently covered with meshed split-thickness autograft, which took well. It is concluded that further development of this model is needed to overcome the hostile wound bed seen in burns patients.     

利用扩张皮瓣取大面积全厚皮片游离移植的临床应用与研究

目的：探讨一种新的大面积全厚皮片取皮方法。方法：利用扩张皮瓣取大面积全厚皮片游离移植治疗大面积体表瘢痕、巨痣等38例次。测量此方法的皮片收缩率，并与其他种类皮片进行比较。结果：本组病例植皮成活96．5％，术后6月皮片收缩程度低于中厚植皮，与普通全厚植皮无差别。结论：利用扩张皮瓣取大面积全厚皮片游离移植治疗大面积体表病变是一种合理可靠的方法。     

Autologous skin transplantation: comparison of minced skin to other techniques

BACKGROUND: Skin grafting may be necessary to close nonhealing skin wounds. This report describes a fast and minimally invasive method to produce minced skin suitable for transplantation to skin wounds. The technique was evaluated in an established porcine skin wound healing model and was compared to split-thickness skin grafts and suspensions of cultured and noncultured keratinocytes. MATERIALS AND METHODS: The study included 90 wounds on 3 pigs. Fluid-treated full-thickness skin wounds were grafted with minced skin, split-thickness skin grafts, noncultured keratinocytes, or cultured keratinocytes. Controls received either fluid or dry treatment. The wound healing process was analyzed in histologies collected at Days 8 to 43 postwounding. Wound contraction was quantified by photoplanimetry. RESULTS: Wounds transplanted with minced skin and keratinocyte suspension contained several colonies of keratinocytes in the newly formed granulation tissue. During the healing phase, the colonies progressed upward and reepithelialization was accelerated. Minced skin and split-thickness skin grafts reduced contraction as compared to keratinocyte suspensions and saline controls. Granulation tissue formation was also reduced in split-thickness skin-grafted wounds. CONCLUSIONS: Minced skin grafting accelerates reepithelialization of fluid-treated skin wounds. The technique is faster and less expensive than split-thickness skin grafting and keratinocyte suspension transplantation. Minced skin grafting may have implications for the treatment of chronic wounds.     

Antecedent thermal injury worsens split-thickness skin graft quality: A clinically relevant porcine model of full-thickness burn,excision and grafting

Current standard of care for full-thickness burn is excision followed by autologous split-thickness skin graft placement. Skin grafts are also frequently used to cover surgical wounds not amenable to linear closure. While all grafts have potential to contract, clinical observation suggests that antecedent thermal injury worsens contraction and impairs functional and aesthetic outcomes. This study evaluates the impact of antecedent full-thickness burn on split-thickness skin graft scar outcomes and the potential mediating factors. Full-thickness contact burns (100 °C, 30 s) were created on the backs of anesthetized female Yorkshire Pigs. After seven days, burn eschar was tangentially excised and covered with 12/1000th inch (300 μm) split-thickness skin graft. For comparison, unburned wounds were created by sharp excision to fat before graft application. From 7 to 120 days post-grafting, planimetric measurements, digital imaging and biopsies for histology, immunohistochemistry and gene expression were obtained. At 120 days post-grafting, the Observer Scar Assessment Scale, colorimetry, contour analysis and optical graft height assessments were performed. Twenty-nine porcine wounds were analyzed. All measured metrics of clinical skin quality were significantly worse (p < 0.05) in burn injured wounds. Histological analysis supported objective clinical findings with marked scar-like collagen proliferation within the dermis, increased vascular density, and prolonged and increased cellular infiltration. Observed differences in contracture also correlated with earlier and more prominent myofibroblast differentiation as demonstrated by α-SMA staining. Antecedent thermal injury worsens split-thickness skin graft quality, likely by multiple mechanisms including burn-related inflammation, microscopically inadequate excision, and dysregulation of tissue remodeling. A valid, reliable, clinically relevant model of full-thickness burn, excision and skin replacement therapy has been demonstrated. Future research to enhance quality of skin replacement therapies should be directed toward modulation of inflammation and assessments for complete excision.     

Early vascularization of syngeneic, allogeneic and xenogeneic skin grafts

The vascularization of syngeneic, allogeneic and xenogeneic skin grafts 3-4 days after grafting was studied in inbred rats by injecting hosts with 51Cr labelled red cells on the third day and counting graft radioactivity on the fourth day. Vascularization as determined by this method was quantitatively similar in syngeneic, allogeneic and mammalian xenogeneic grafts, while the vascularization of non-mammalian xenografts was significantly inferior. For any one donor-host combination, full-thickness grafts contained relatively more blood than did split-thickness grafts, presumably because of the large vessels in the deep part of the dermis in full-thickness grafts. Full-thickness neonatal grafts were vascularized similarly to full-thickness adult skin grafts. Grafted skin contained relatively more blood than did the corresponding normal skin. Reconstituted freeze dried allogeneic skin grafts contained virtually no blood, a phenomenon possibly analogous to the 'no reflow' phenomenon of microsurgery. The inferior vascularization of non-mammalian xenografts is more plausibly explained on the basis of defective self recognition than as representing a reaction to foreign determinants. These results do not necessarily indicate that one type of graft is better than another in clinical practice. But if the beneficial effects of temporary skin grafts do indeed depend on their capacity to become vascularized, fresh skin appears preferable to reconstituted freeze dried skin.     

Charles procedure for lymphedema: A warning

Five patients with lower extremity lymphedema treated by subcutaneous excision and split-thickness graft resurfacing (from the opposite extremity) have been followed up. Three of these patients underwent amputation of the leg because of exophytic changes within the grafted skin, chronic cellulitis and skin breakdown. Resurfacing with a split-thickness graft causes a deformity that is significantly worse than the original lymphedema.In the Charles procedure (subcutaneous and deep fascial excision followed by full-thickness grafts), deep muscle fascia should be excised with the subcutaneous tissue and the extremity resurfaced with more durable full-thickness grafts taken from the excised tissue. However, the risks of graft failure should be considered.Over the past 9 years, 25 patients with lymphedema have been successfully managed by staged subcutaneous excision beneath flaps. This procedure safely provides consistent reduction in size, improvement in function and very satisfactory esthetic results. In the author's opinion the Charles procedure is therefore preferred for treating lymphedema of the extremity.     

Transplantation of acellular dermis and keratinocytes cultured on porous biodegradable microcarriers into full-thickness skin injuries on athymic rats

In search of an optimal transplantation regime for sufficient dermal and epidermal regeneration after a full-thickness skin injury, wounds on athymic rats were grafted with split-thickness skin grafts or acellular human dermis followed by transplantation with human keratinocytes either in single-cell suspension or cultured on porous biodegradable microcarriers. After 2 weeks, all wounds grafted with acellular human dermis showed a well organised and vascularised dermal component and reepithelialisation on the grafted dermal matrix was complete 21 days after transplantation with human keratinocytes. Wounds grafted with human keratinocytes seeded on biodegradable microcarriers or split-thickness skin grafts displayed over time (i.e. 16-21 days post-transplantation) a significantly thicker epithelial cell layer in comparison to wounds grafted with keratinocytes in single-cell suspensions or microcarriers not seeded with cells. Furthermore, measurements of dermal thickness in the closed wounds 21 days after grafting showed a significantly thicker and well organised neodermal component in wounds transplanted with keratinocytes seeded on microcarriers or split-thickness skin grafts compared to all other wounds. Positive immunostaining towards von Willebrand factor revealed the plausible proangiogenic effects of transplantation with keratinocytes seeded on microcarriers. Analysis of representative tissue sections after fluorescence in situ hybridisation visualised that grafted human keratinocytes were present in the epidermal layers covering the wounds 16 and 21 days after transplantation, strongly indicating preservation of cell viability. These results shows that the use of biodegradable microcarriers in the culture of autologous keratinocytes for treatment of full-thickness wounds not only facilitate the cultivation, transportation and transplantation processes but also enhances the dermal regeneration induced by a dermal scaffold which results in a clinical result that is significantly superior to the one obtained when keratinocytes are transplanted in a single-cell suspension.     

Total full-thickness skin grafting for treating patients with extensive facial burn injury: A 10-year experience

IntroductionFacial burns are not only a severe burn injury, but result in psychological disturbance. The improvement of the methods of treating facial burns remains topical. The aim of the study was to evaluate the effectiveness of approach based on full-thickness skin autografting for facial burn injuries.MethodsDuring 2000–2019, ninety seven patients with the facial burn were treated in Burn Center. All patient were divided into two groups. The comparative analysis between groups was done.ResultsGroup A was treated with full-thickness skin grafts (42 patients – 43.3%). Since 2010, total full-thickness skin graft was used in 11 patients from Group A. In group B, 55 patients (56.7%) were treated with split-thickness skin grafts, including 9 patients (16.4%) with total split-thickness skin graft transplantation. Total full-thickness skin graft was performed in case of a deep and extensive facial burn and cicatricial deformities. During the long-term period, a positive cosmetic result and the absence of indications for reconstructive operations were noted.ConclusionThe approach of facial burn treatment based on total full-thickness skin graft allows conditions for engraftment and adaptation of autograft, reduces the risk of scar developing and achieves maximum cosmetic results of treatment.     

Effect of skin graft thickness on scar development in a porcine burn model

Animal models provide a way to investigate scar therapies in a controlled environment. It is necessary to produce uniform, reproducible scars with high anatomic and biologic similarity to human scars to better evaluate the efficacy of treatment strategies and to develop new treatments. In this study, scar development and maturation were assessed in a porcine full-thickness burn model with immediate excision and split-thickness autograft coverage. Red Duroc pigs were treated with split-thickness autografts of varying thickness: 0.026 in. (“thin”) or 0.058 in. (“thick”). Additionally, the thin skin grafts were meshed and expanded at 1:1.5 or 1:4 to evaluate the role of skin expansion in scar formation. Overall, the burn-excise-autograft model resulted in thick, raised scars. Treatment with thick split-thickness skin grafts resulted in less contraction and reduced scarring as well as improved biomechanics. Thin skin autograft expansion at a 1:4 ratio tended to result in scars that contracted more with increased scar height compared to the 1:1.5 expansion ratio. All treatment groups showed Matrix Metalloproteinase 2 (MMP2) and Transforming Growth Factor β1 (TGF-β1) expression that increased over time and peaked 4 weeks after grafting. Burns treated with thick split-thickness grafts showed decreased expression of pro-inflammatory genes 1 week after grafting, including insulin-like growth factor 1 (IGF-1) and TGF-β1, compared to wounds treated with thin split-thickness grafts. Overall, the burn-excise-autograft model using split-thickness autograft meshed and expanded to 1:1.5 or 1:4, resulted in thick, raised scars similar in appearance and structure to human hypertrophic scars. This model can be used in future studies to study burn treatment outcomes and new therapies.     

Principles and practices for treatment of cutaneous wounds with cultured skin substitutes

BACKGROUND: Skin substitutes prepared from cultured skin cells and biopolymers may reduce requirements for donor skin autograft, and have been shown to be effective in treatment of excised burns, burn scars, and congenital skin lesions. DATA SOURCES: Cultured skin substitutes (CSS) generate skin phenotypes (epidermal barrier, basement membrane) in the laboratory, and restore tissue function and systemic homeostasis. Healed skin is smooth, soft and strong, but develops irregular degrees of pigmentation. Quantitative analysis demonstrates that CSS closes 67 times the area of the donor skin, compared to less than 4 times for split-thickness skin autograft. CONCLUSIONS: CSS reduce requirements for donor skin autograft for closure of excised, full-thickness cutaneous wounds, and demonstrate qualitative outcome that is not different from meshed, split-thickness autograft. These results offer reductions in morbidity and mortality for the treatment of burns and chronic wounds, and for cutaneous reconstruction.     

VERSAJETtm Hydrosurgery Technique for the Preparation of Full Thickness Skin Grafts and the Creation of Retrograde Split Thickness Skin Grafts

Full- and split-thickness skin grafts continue to serve a vital role in lower extremity wound coverage, and meticulous preparation of the recipient site is vital to incorporation of the transplanted skin. A technique for the rapid, controlled preparation of full-thickness skin grafts and creation of thick-split thickness skin grafts from full-thickness donor tissue, using a high-pressure stream of saline solution, is described.     

In vivo cultured skin composed of two-layer collagen sponges with preconfluent cells.

Although various kinds of cultured skin substitutes have been developed, it takes several weeks to produce them before grafting. In their previous study, the authors succeeded in producing cultured skin easily in a short period of time by layering two collagen sponges. In the current study, to shorten this period even further, they grafted the cell-preconfluent artificial skin immediately after seeding the cells. They used two collagen sponges with different pore sizes and crosslink densities. They seeded 1,000,000 cells per square centimeter of fibroblasts and 1,000,000 cells per square centimeter of keratinocytes on the respective collagen sponges and grafted them on a full-thickness, excised wound on the back of severe combined immunodeficient mice. Two weeks after grafting, epithelium and dermislike tissue were formed. They then decreased the number of keratinocytes and grafted them. Four weeks after grafting, at seeding densities of 50,000 to 1,000,000 cells per square centimeter of keratinocytes, the preconfluent artificial skin took histologically, and human type IV and type VII collagen were stained immunohistochemically. This cell-preconfluent artificial skin composed of two-layer collagen sponges seems promising for widespread clinical use.     

A novel recombinant human collagen hydrogel as minced split-thickness skin graft overlay to promote full-thickness skin defect reconstruction

To overcome limited donor-site availability in patients with extensive burns, split-thickness skin grafts (STSGs) are sometimes minced into micrografts (MGs) to improve the expansion ratio of the grafts, but this may reduce wound healing. We aimed to produce a novel hydrogel as an overlay of minced STSGs to improve wound healing. The new hydrogel was produced using recombinant human collagen type III powder as a raw material. Morphological and physical characteristics (degradation and swelling rate), cytotoxicity, and cell viability of the hydrogel were evaluated in vitro. A full-thickness in vivo skin defect model was constructed with male Sprague-Dawley rats. The animals were randomly assigned to experimental and control groups in which the new hydrogel and Vaseline gauze, respectively, were overlaid on minced STSGs to repair and regenerate skin wound. The healing rates and recovery status were compared between the two groups. The hydrogels exhibited good water retention properties and a suitable degradation rate, which can promote the proliferation and migration of wound healing-related cells in vitro. Further, using the hydrogel as an overlay accelerated wound closure and angiogenesis, increased dermal tissue and basement membrane formation, enhanced collagen synthesis and wound healing-related growth factor expression, while reducing scar formation compared to the Vaseline gauze group. In conclusion, the novel, low-cost recombinant human collagen hydrogel can accelerate wound closure and improve wound healing when used as an overlay of minced STSGs. The new hydrogel could become a new treatment option for traumatic skin wounds caused by burns or injuries.     

Cutometrical measurement confirms the efficacy of the composite skin grafting using allogeneic acellular dermis in burns

Measurement of viscoelasticity of the skin using the device called cutometer seems to be a very precise and promising diagnostic method in different skin pathologies. However, only a very limited number of reports dealing with the use of cutometer in burns is available. The composite skin grafting using an allogeneic acellular dermis covered with a thin epidermal autologous graft is supposed to improve viscoelastic properties of grafted skin in full-thickness burns. Cutometer MPA 580 has been used for examination of healthy skin, healed and maturated autologous split-thickness skin grafts, and in two patiens 6 years after composite skin grafting using the allogeneic acellular dermis + thin autologous epidermal graft in one stage. Typical curves defined by values of R0-R9 parameters are presented. These data document significantly better viscoelastic properties of composite skin grafts than those of conventional split-thickness skin grafts after 6 years. Measurements of viscoelasticity of the skin, using a cutometer, will probably bring useful and precise data for evaluation of the reconstructed skin in burns. Significantly better properties of the composite skin graft were assessed clinically and measured by Cutometer MPA 580 6 years after surgery.