“Shift to right flypaper technique” a refined method for postage stamp autografting preparation

A novel skin grafting modality: prefabricated large sheet of postage-stamp autografts and allografts to repair extensive burn wounds; a prospective matched-control study

BACKGROUND

The excessively long operative time has been the greatest barrier to the success of transplanting postage-stamp auto- and allografts directly and piece-by-piece onto extensive burn wounds. To solve this challenge, the authors present a novel grafting modality, that is, the prefabricated-large-sheet grafting that moves the labor-intensive and time-consuming process of grafts-positioning before grafting and thereby markedly shortens the operative time.

METHODS

Twenty-one operations using the novel modality were performed on 11 patients with extensive deep burns. The grafting time using the novel modality was recorded and compared with that of the conventional piece-by-piece grafting. Eventually, the take rates of the two modalities were compared.

RESULTS

All patients were healed and discharged. The average grafting time per unit area (100 cm2) of prefabricated-large-sheet grafting and piece-by-piece grafting were (0.41±0.09) min and (7.46±1.07) min, respectively, and the difference is statistically significant(P<0.001). The average take rate of the prefabricated sheets was (85.43±6.14)% and that of the piece-by-piece transplanted grafts was (87.29±5.23)% and there is no significant difference(P>0.05).

CONCLUSIONS

The prefabricated-large-sheet grafting significantly reduces the intraoperative grafting time while ensures uniformity of the skin grafts and secures good outcomes, thereby making the intermingled transplantation of postage-stamp auto- and allografts, which has been an excellent modality per se but limited to repair small residual wounds, now feasible to repair extensive deep burn wounds. It is worth wider understanding and application in the treatment of extensive deep burns.

Autologous and not allogeneic adipose-derived stem cells improve acute burn wound healing

Adipose-derived stem cells (ADSCs) transplant has been reported to be a potential treatment for burn wounds. However, the effects of autogenicity and allogenicity of ADSCs on burn wound healing have not been investigated and the method for using ADSCs still needs to be established. This study compared the healing effects of autologous and allogenic ADSCs and determined an optimal method of using ADSCs to treat acute burn wounds. Experiments were performed in 20 male Wistar rats (weight, 176-250 g; age, 6-7 weeks). Two identical full-thickness burn wounds (radius, 4 mm) were created in each rat. ADSCs harvested from inguinal area and characterized by their high multipotency were injected into burn wounds in the original donor rats (autologous ADSCs group) or in other rats (allogenic ADSCs group). The injection site was either the wound center or the four corners 0.5 cm from the wound edge. The reduction of burn surface areas in the two experimental groups and in control group were evaluated with Image J software for 15 days post-wounding to determine the wound healing rates. Wound healing was significantly faster in the autologous ADSCs group compared to both the allogenic ADSCs group (p<0.05) and control group (p<0.05). Wound healing in the allogenic ADSC group did not significantly differ from that in control group. Notably, ADSC injections 0.5cm from the wound edge showed significantly improved healing compared to ADSCs injections in the wound center (p<0.05). This study demonstrated the therapeutic efficacy of ADSCs in treating acute burn wounds in rats. However, only autologous ADSCs improved healing in acute burn wounds; allogenic ADSCs did not. This study further determined a superior location of using ADSCs injections to treat burn wounds including the injection site. Future studies will replicate the experiment in a larger and long-term scale burn wounds in higher mammalian models to facilitate ADSCs therapy in burn wound clinical practice.

Skin tissue engineering advances in severe burns: review and therapeutic applications

Current advances in basic stem cell research and tissue engineering augur well for the development of improved cultured skin tissue substitutes: a class of products that is still fraught with limitations for clinical use. Although the ability to grow autologous keratinocytes in-vitro from a small skin biopsy into sheets of stratified epithelium (within 3 to 4 weeks) helped alleviate the problem of insufficient donor site for extensive burn, many burn units still have to grapple with insufficient skin allografts which are used as intermediate wound coverage after burn excision. Alternatives offered by tissue-engineered skin dermal replacements to meet emergency demand have been used fairly successfully. Despite the availability of these commercial products, they all suffer from the same problems of extremely high cost, sub-normal skin microstructure and inconsistent engraftment, especially in full thickness burns. Clinical practice for severe burn treatment has since evolved to incorporate these tissue-engineered skin substitutes, usually as an adjunct to speed up epithelization for wound closure and/or to improve quality of life by improving the functional and cosmetic results long-term. This review seeks to bring the reader through the beginnings of skin tissue engineering, the utilization of some of the key products developed for the treatment of severe burns and the hope of harnessing stem cells to improve on current practice.

Challenging the Conventional Therapy: Emerging Skin Graft Techniques for Wound Healing

BACKGROUND

Split-thickness skin grafting is the current gold standard for treatment of major traumatic skin loss. However, split-thickness skin grafting is limited by donor-skin availability, especially in large burns. In addition, the donor-site wound is associated with pain and scarring. Multiple techniques have been developed in the past to overcome these limitations but have been unable to achieve clinical relevance. In this study, the authors examine the novel emerging skin grafting techniques, aiming to improve the utility of split-thickness skin grafting.

METHODS

An extensive literature review was conducted on PubMed, MEDLINE, and Google Scholar to look for new skin grafting techniques. Special focus was given to techniques with potential for large expansion ratio and decreased donor-site pain.

RESULTS

The new modalities of modified skin grafting technique, discussed in this article, include (1) Xpansion Micrografting System, (2) fractional skin harvesting, (3) epidermal suction blister grafting, and (4) ReCell technology. These techniques are able to achieve significantly increased expansion ratios compared with conventional split-thickness skin grafting and also have decreased donor-site morbidity.

CONCLUSIONS

These techniques can be used separately or in conjunction with split-thickness skin grafting to overcome the associated pitfalls. Further studies and clinical trials are needed to define the utility of these procedures and where they fit into routine clinical practice.

The micrograft concept for wound healing: strategies and applications

The standard of care for wound coverage is to use an autologous skin graft. However, large or chronic wounds become an exceptionally challenging problem especially when donor sites are limited. It is important that the clinician be aware of various treatment modalities for wound care and incorporate those methods appropriately in the proper clinical context. This report reviews an alternative to traditional meshed skin grafting for wound coverage: micrografting. The physiological concept of micrografting, along with historical context, and the evolution of the technique are discussed, as well as studies needed for micrograft characterization and future applications of the technique.

Adult burn patients with more than 60% TBSA involved-Meek and other techniques to overcome restricted skin harvest availability--the Viennese Concept

Despite the fact that early excision and grafting has significantly improved outcome over the last decades, the management of severely burned adult patients with >/=60% total body surface area (% TBSA) burned still represents a challenging task for burn care specialists all over the world. In this article, we present our current treatment concept for this entity of severely burned patients and analyze its effect in a comparative cohort study. Surgical strategy comprised the use of split-thickness skin grafts (Meek, mesh) for permanent coverage, fluidized microsphere bead-beds for wound conditioning, temporary coverage (polyurethane sheets, Epigard; nanocrystalline silver dressings, Acticoat; synthetic copolymer sheets based on lactic acid, Suprathel; acellular bovine derived collagen matrices, Matriderm; allogeneic cultured keratinocyte sheets; and allogeneic split-thickness skin grafts), and negative-pressure wound therapy (vacuum-assisted closure). The autologous split-thickness skin graft expansion using the Meek technique for full-thickness burns and the delayed approach for treating dorsal burn wounds is discussed in detail. To demonstrate differences before and after the introduction of the Meek technique, we have compared patients of 2007 with >/=60% TBSA (n = 10) to those in a matched observation period (n = 7). In the first part of the comparative analysis, all patients of the two samples were analyzed with regard to age, abbreviated burn severity index, Baux, different entities of % TBSA, and survival. In the second step, only the survivors of both years were separated in two groups as follows: patients receiving skin grafts, using the Meek technique (n = 6), were compared with those without Meek grafting (n = 4). When comparing the severely burned patients of 2007 with a cohort of 2006, there were no differences for age (2007: 46.4 +/- 13.4 vs. 2006: 39.1 +/- 14.8 years), abbreviated burn severity index score (2007: 12.2 +/- 1.0 vs. 2006: 12.1 +/- 1.2) or % TBSA (2007: 72.1 +/- 11.7 vs. 2006: 69.3 +/- 8.7% TBSA). In these two rather small groups of severely burned patients with >/=60% TBSA, the overall survival rate of patients was 70.0% (7/10) in 2007 and 42.9% (3/7) in 2006, respectively. Almost all nonsurvivors in both years died within the first 5 days after admission. If assessing the different treatment modalities of the survivors, we found that although the Meek group patients were older (Meek 48.8 +/- 13.3 vs. non-Meek 26.8 +/- 11.5 years, P = .0381) and had consequently higher Baux scores (Meek 124.0 +/- 2.9 vs. non-Meek 93.8 +/- 8.5, P = .0095) than the non-Meek patients, this seemed to have no effect on length-of-stay (80.5 +/- 9.7 vs. non-Meek 79.8 +/- 33.0 days), hospital length-of-stay (85.7 +/- 14.8 vs. non-meek 84.3 +/- 26.1 days) or number of operations (6.5 +/- 1.0 vs. non-Meek 7.0 +/- 4.1 operations). The achieved results represent a combination of various treatment changes and, therefore, cannot be attributed to a single modality. The Meek technique is one of the technical options to choose from, to achieve permanent skin replacement; we think that it has its place if integrated in a whole treatment concept for management of severely burned patients.