[Repair mechanisms of the wounds with exposed bone structures using an artificial dermis].

Objective: To investigate the repair mechanisms of the wounds with bone exposed by artificial dermis transplantation. Methods: Seventy two rabbits were randomly divided into 3 groups of 24 rabbits, the wound model was made on the top of head. In the skin defect group (SD group), skin was removed and skull periosteum was retained. In the periosteal defect group (PD group), the skin and skull periosteum were both removed, and the skull was exposed. In the skull burn group (SB group), after the periosteum was removed, the exposed skull bone was burned out with electric iron to cause skull surface necrosis, then the artificial dermis transplantation were performed in each group. In 1, 2, 3 and 4 weeks after transplantation, 2 specimens including artificial dermis and the underlying tissue in each group were cut for biopsy with HE staining to observe the angiogenesis in artificial dermis. Evans Blue perfusion was performed in four animals from each group to quantify angiogenesis in artificial dermis. Results: One week after transplantation, in SD group, a few microvessels can be observed in artificial dermis, but in the rest of the two groups, only a small amount of inflammatory cells can be seen. Two weeks after transplantation, in SD group, a large number of new blood vessels and fibroblasts can be seen filling in the artificial dermis, but angiogenesis delayed obviously in the PD and SB group. Three weeks after transplantation, the angiogenesis of artificial dermis in the PD and SB group accelerated obviously, and a thin layer of blood rich tissue membrane can be seen over the burned skull. The Evans Blue perfusion showed that the content of dye perfusion in the artificial dermis was closed to the peek value at 2 weeks after transplantation in the SD group, which was significantly higher than that in PD and SB group [(2 741±976) vs (1 039±590) and (403±209) µg/g, P<0.01]. Three weeks after transplantation, the content of Evans Blue in artificial dermis reached the peek value in SD and PD group, no significant difference was found between this two groups, but both significantly higher than that in SB group [(2 943±793) and (2 255±316) vs (1 125±404) µg/g, P<0.01]. Four weeks after transplantation, the content of Evans Blue in artificial dermis reached the peek value in SB group, although the value was still lower than that in SD and PD group, the difference was not significant [(1 609±787) vs (2 298±778) and (2 141±385) µg/g, P>0.05]. Conclusions: Lack or injury of periosteum can cause vascularization delay after artificial dermis transplantation. The vascularization of artificial dermis mainly originates from the normal tissues surrounding the wound when artificial dermis is transplanted on the wound with periosteum defect or bone exposed.

Fibrin gel as a scaffold for skin substitute ­ production and clinical experience.

The purpose of this study was to create a fibrin-based human skin substitute in vitro with epidermal and dermal component and to assess its healing potential in deep partial and full thickness burns. Fibrin scaffolds were prepared from commercial fibrin glue kits. Human fibroblasts were cultured in fibrin gel. Human keratinocytes were seeded on the top of the gel. Viability of cells was determined fluorimetrically. Scanning electron microscope and immunocytochemistry analysis of cultured cells were performed. After hydrosurgical preparation of deep burn necrotic tissue, wound bed was prepared for skin substitutes. Progress of healing was documented using visual estimation and photos. Scanning electron microscope images showed good cell attachment and colony spreading of keratinocytes and fibroblasts on fibrin scaff old. Immunofluorescent staining of cell cultures on fibrin scaffold showed expression of vimentin, a marker of fibroblast cells, cytokeratin 19, a marker of epithelial stem cells, as well as involucrin, a marker of differentiated keratinocytes. Clinical results clearly showed that appearance of the skin did not differ significantly from the areas of transplanted skin using split-thickness skin graft techniques. In conclusion, using these fibrin-cultured autografts on massive full-thickness burn resulted in good healing.

Dermal substitutes: an alternative for the reconstruction of large full-thickness defects in the plantar surface.

Large defects in plantar surface secondary to acral melanoma excision can be difficult to repair with local flaps, and skin grafts in weight-bearing surfaces often suffer necrosis causing prolonged disability. Acellular dermal matrices represent an easy alternative to cover deep wounds or those with bone or tendon exposure. Despite their high cost and the requirement of two surgical procedures, this alternative may offer excellent functional and aesthetic results in acral defects.

[Research advances on the characteristics and wound healing promoting effect of in-situ forming injectable hydrogels].

Research of in-situ induced repair and regeneration is a multi- and inter-disciplinary field, which is of important potentials in the treatment of both large-area deep burns and chronic wounds such as diabetic skin ulcers. In-situ forming injectable hydrogels which are hydrogel-like biomaterials that can spontaneously gelatinize in physiological condition when applied in local wounds have been explored in recent years. This kind of biomaterials contain extracellular matrix, in which cells promoting wound repairing can be added if required, and can work as release-controlled carriers for active peptides such as growth factors to simulate local wound microenvironment and induce the repair and regeneration. Herein, characteristics and function of promoting wound repair and regeneration about in-situ forming injectable hydrogels were reviewed, including material types and their relevant working mechanisms, advantages, existing problems, etc.

[Clinical effect of bi-layered artificial dermis and autologous skin graft in repairing bone and/or tendon exposed wounds].

Objective: To explore the clinical effect of bi-layered artificial dermis combined with autologous skin graft in the repair of wounds with exposed bone and/or tendon. Methods: The medical records of 25 patients (aged 3 to 79 years, including 21 males and 4 females) with bone and/or tendon exposed wounds caused by various reasons, admitted to Nanfang Hospital of Southern Medical University from May 2014 to December 2018 were analyzed retrospectively. Of the 25 patients, 7 patients had exposed bone only, 13 patients had exposed tendon only, and 5 patients had exposure of both bone and tendon. The total wound area was 78.0 (53.4, 103.2) cm(2). The widths of bone exposure and tendon exposure were 3.2 (3.0, 3.6) cm and 2.0 (1.7, 2.4) cm, respectively. All wounds were implanted with bi-layered artificial dermis in the first stage after thorough wound debridement. After 2 to 3 weeks of vascularization of artificial dermis, autologous thin-to-medium-thickness skins or split-thickness skins were grafted to repair the wounds in the second stage. The vascularization of artificial dermis and its time, whether or not producing hematoma, the skin graft survival rate on day 7 post autologous skin grafting, whether or not repeating skin grafting, and the time of complete wound healing were observed and recorded. The patients were further followed up and observed for 3 or more months after discharge. Results: The vascularization of artificial dermis was achieved in 24 patients after the first transplantation with vascularization time being 11-21 (16±4) days. No hematoma was observed in the transplanted artificial dermis. Failed vascularization of grafted artificial dermis was observed in one patient who was later treated with negative pressure drainage and skin grafting alone, and was discharged with wound healing. The skin graft survival rate on day 7 post autologous skin grafting was 92.2%-100.0% ( (99.3±1.3)%), with the remaining wound areas recovered later by themselves or healed by dressing changes without repeated skin grafting. The complete wound healing time was 7-19 (11.9±2.8) days after autologous skin grafting. The patients were followed up for 3 to 60 months after discharge. Except for the pigmentation in skin graft area, the skin grafts survived well, being soft in texture and with no repeated ulceration, obvious hypertrophic scar, or contracture deformity. Conclusions: Artificial dermis combined with autologous skin grafting can effectively repair wounds with bone and/or tendon exposure, providing a repair strategy for this type of wounds.

[National expert consensus on the application of natural dermal matrix in wound repair (2020 version)].

Natural dermal matrix has good biocompatibility and can serve as " biological template" in wound repair. According to the source of material, natural dermal matrix can be divided into acellular dermal matrix (ADM), denatured dermal matrix, and scar dermal matrix. ADM is a biological material prepared by removing cellular components from the skin and retaining extracellular matrix (ECM) of the dermis. ADM possesses abundant natural biological information, low immunogenicity, and excellent regenerative capacity, which has greatly promoted the development of wound healing specialty as dermal substitute. Denatured dermis matrix is a layer of dermal tissue made by superficial tangential excision or dermabrasion on deeply burned wounds. The retained denatured dermis can recover gradually after transplantation of autologous skin on its surface, with similar structure, morphology, and biomechanics to healthy dermis. Scar dermal matrix is a kind of dermal scaffold made of autologous split-thickness scar tissue, possessing the characteristics of high survival rate, good texture, and slight scar reaction. Scar dermal matrix can effectively reduce secondary damage to the donor site when repairing scar contracture deformity. Based on the research progress at home and abroad and the opinions of domestic experts, this paper summarizes the indications, application methods, contraindications, and considerations of different types of natural dermal matrix in application of wound repair.

[Research status and prospect on autologous tissue-engineered skin as permanent graft].

To date, skin substitute that can provide permanent wound closure is still autologous tissue-engineered skin using autologous skin cells as seed cells. The development of cultured epithelial autograft has experienced a long and tortuous process. Autologous tissue-engineered composite skin is closer to autologous split-thickness skin graft in terms of structure, function, and efficacy, which has become a research focus in recent years. Based on the actual status of research on tissue-engineered skin application, this paper reviewed the main research progresses and existing problems, and the prospect of research and development and clinical application of autologous tissue-engineered skin as permanent graft in order to provide a reference for the improvement and application of autologous tissue-engineered skin.

Human skin models: From healthy to disease-mimetic systems; characteristics and applications.

Skin drug delivery is an emerging route in drug development, leading to an urgent need to understand the behaviour of active pharmaceutical ingredients within the skin. Given, As one of the body's first natural defences, the barrier properties of skin provide an obstacle to the successful outcome of any skin drug therapy. To elucidate the mechanisms underlying this barrier, reductionist strategies have designed several models with different levels of complexity, using non-biological and biological components. Besides the detail of information and resemblance to human skin in vivo, offered by each in vitro model, the technical and economic efforts involved must also be considered when selecting the most suitable model. This review provides an outline of the commonly used skin models, including healthy and diseased conditions, in-house developed and commercialized models, their advantages and limitations, and an overview of the new trends in skin-engineered models.

[Analysis of clinical effects of artificial dermis in functional reconstruction in the late stage of extremely severe burn].

Objective: To explore the clinical effects of artificial dermis combined with autologous split-thickness skin transplantation in the treatment of functional reconstruction in the late stage of extremely severe burn. Methods: From May 2015 to May 2017, medical records of 40 patients with limited activity after scar hyperplasia and conforming to the study criteria, injured in August 2nd Kunshan factory aluminum dust explosion accident in 2014, and had surgeries in our hospital and rehabilitation treatment in our hospital's alliance rehabilitation hospital, Rehabilitation Hospital of Kunshan Zhou City, were retrospectively analyzed. According to the treatment methods, 20 patients (12 males and 8 females, aged 20 to 45 years) were enrolled in artificial dermis group. They were conducted with stage Ⅰ functional site scar loosening and artificial dermis (PELNAC) implanting+ stage Ⅱ transplantation of autologous split-thickness skin. Another 20 patients (14 males and 6 females, aged 20 to 45 years) were enrolled in conventional skin grafting group. They were conducted with stage Ⅰ functional site scar loosening and transplantation of autologous thin medium-thickness skin. After 5 days of autologous skin transplantation, the survival rates of autologous skin in patients of 2 groups were calculated. The autologous skin infection and complete healing time of skin grafting area in patients of 2 groups were recorded. In 3, 6, and 10 months after autologous skin transplantation, the Vancouver Scar Scale (VSS) was used to assess the scar condition of recipient site in patients of 2 groups. The complete healing time of donor site in patients of 2 groups was recorded. In 10 months after autologous skin transplantation, VSS was used to assess the scar condition of donor site in patients of 2 groups. In 12 months after autologous skin transplantation, the functional recovery of surgical function reconstruction site in patients of 2 groups was evaluated and rated. Data were processed with t test, analysis of variance for repeated measurement, Wilcoxon rank-sum test, chi-square test, Fisher's exact probability test, and Bonferroni correction. Results: (1) After 5 days of autologous skin transplantation, the survival rate of autologous skin in patients of artificial dermis group was (95±3)%, similar to (93±3)% in conventional skin grafting group (t=1.262, P>0.05). The results of autologous skin infection of patients in the 2 groups were similar (P>0.05). (2) After autologous skin grafting, the complete healing time of skin grafting area in patients of artificial dermis group was (12.3±2.5) d, similar to (12.7±2.0) d of conventional skin grafting group (t=-0.139, P>0.05). In 3, 6, and 10 months after autologous skin transplantation, the VSS scores of scars in recipient site of patients in artificial dermis group were significantly lower than those of conventional skin grafting group (t=-4.428, -5.655, -6.839, P<0.01). (3) After autologous skin grafting, the complete healing time of donor site in patients of artificial dermis group was obviously shorter than that in conventional skin grafting group (t=-12.435, P<0.01). In 10 months after autologous skin transplantation, the VSS score in donor site of patients in artificial dermis group was significantly lower than that of conventional skin grafting group (t=-16.971, P<0.01). (4) After 12 months of autologous skin transplantation, the functional improvement levels of the functional site of patients in artificial dermis group were good in 4 patients, fair in 15 patients, and bad in 1 patient, while the functional improvement levels of the functional site of patients in conventional skin grafting group were good in 5 patients, fair in 8 patients, and bad in 7 patients. The functional improvement levels of the functional site of patients between the two groups were similar (Z=371.5, P>0.05). Conclusions: Compared with conventional stage Ⅰ functional site scar loosening and transplantation of autologous thin medium-thickness skin, stage Ⅰ functional site scar loosening and artificial dermis implanting+ stage Ⅱ transplantation of autologous split-thickness skin does not affect the survival of skin in the early stage and can effectively improve functional site function, reduce VSS scores of donor site and recipient site, and shorten complete healing time of donor site.

[Experts consensus on clinical application of bilayer artificial dermis (2019 version)].

Artificial dermis is a kind of tissue engineering dermal substitute and is used to repair dermal defects caused by a variety of reasons. This article describes the characteristics and the mechanism of repair and reconstruction of bilayer artificial dermis. Based on domestic experience of clinical applications and relative literature of bilayer artificial dermis, more than 50 domestic experts in related field reached a consensus on indications, contraindications, operation procedures in clinical application, cautions, and treatment and prevention of complications of bilayer artificial dermis, providing reference for clinical application.

Is allograft skin, the gold-standard for burn skin substitute? A systematic literature review and meta-analysis.

BACKGROUND: Allograft skin (AS) transplantation has been considered to be the gold standard for replacing tissue damage, following burns. However, increasingly new biosynthetic skin substitutes are being developed as alternatives. The objective of this systematic review is to compare AS with other skin substitutes, which have been used in the treatment of burns. METHODS: Randomized clinical trial (RCT) and nonrandomized clinical trial (NRCT) studies comparing AS to any other skin substitute in the treatment of burns were extracted from PubMed/Medline, Scopus, EMBASE, and Web of Science. For the risk of bias analysis, the Cochrane bias risk handbook was used for RCT studies and ROBINS-1 was used for NRCT studies. Outcomes such as healing, self-grafting, scar appearance, and mortality were evaluated. RESULTS: Twelve RCT and six NRCT were selected, with most of the methodologies presenting a high risk of bias. Based on the outcomes of the studies, it was not possible to detect any advantages for using AS, as opposed to other skin substitutes. In the meta-analysis, only two outcomes could be evaluated: healing and graft take percentage; however, no significant differences were observed between the groups. CONCLUSION: Because of the poor quality of the primary studies, it was not possible to identify differences in the results that compared the use of AS with other substitutes in the treatment of patients with burns. These results support the fact that surgeons primarily base the choice of skin substitute on clinical experience and cost, at least when treating burns.

[Antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats].

Objective: To study the antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats. Methods: (1) Each one standard strain of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were selected. Each 20 clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were collected from those isolated from wound exudates of burn patients hospitalized in our wards from January 2014 to December 2016 according to the random number table. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of compound lysostaphin disinfectant to above-mentioned strains were detected. The experiment was repeated 3 times. Compared with the corresponding standard strain, the clinical strain with higher MIC and/or MBC was considered as having decreased sensitivity to the disinfectant. The percentage of strains of each of the three kinds of bacteria with decreased sensitivity was calculated. (2) Artificial dermis pieces were soaked in compound lysostaphin disinfectant for 5 min, 1 h, 2 h, and 4 h, respectively, with 21 pieces at each time point. After standing for 0 (immediately), 12, 24, 36, 48, 60, 72 h (with 3 pieces at each time point), respectively, the diameters of their inhibition zones to standard strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were measured. The experiment was repeated 3 times. The shortest soaking time corresponding to the longest standing time, after which the disinfectant-soaked artificial dermis could form an effective inhibition zone (with diameter more than 7 mm), was the sufficient soaking time of the disinfectant to the artificial dermis. (3) Forty Sprague-Dawley rats were divided into post injury day (PID) 3, 7, 14, and 21 sampling groups according to the random number table, with 10 rats in each group. A full-thickness skin defect wound with a diameter of 20 mm was made on both sides of the spine on the back of each rat. Immediately after injury, the artificial dermis without any treatment was grafted on the wound on left side of the spine (hereinafter referred to as control wound), while the sufficiently soaked artificial dermis with compound lysostaphin disinfectant was grafted on the wound on right side of the spine (hereinafter referred to as disinfectant wound). On PID 3, 7, 14, and 21, the gross condition of wounds of all the surviving rats was observed, and the new infection rates of control wounds and disinfectant wounds were calculated. Then, the rats in the sampling group with corresponding time were killed, and the full-thickness wound tissue containing artificial dermis was collected for quantitative analysis of bacteria. Bacteria content of the uninfected control wounds and that of the uninfected disinfectant wounds were compared. Data were processed with chi-square test and Wilcoxon rank sum test. Results: (1) The MIC of compound lysostaphin disinfectant to standard strains of Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter baumannii were 1/32, 1/32, and 1/512 of the original concentration of the disinfectant, respectively, and the MBC were 1/32, 1/16, and 1/512 of the original concentration of the disinfectant, respectively. The percentages of clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii and Staphylococcus aureus with decreased sensitivity to compound lysostaphin disinfectant were 15% (3/20), 20% (4/20), and 10% (2/20), respectively. (2) After being soaked in compound lysostaphin disinfectant for 2 and 4 h, the longest standing time, after which the artificial dermis could form an effective inhibition zone against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, were 24, 36, and 48 h respectively, longer than 12, 24, and 24 h of soaking for 5 min and 24, 24, and 36 h of soaking for 1 h. The sufficient soaking time of compound lysostaphin disinfectant to artificial dermis was 2 h. (3) On PID 3, no infection symptom was observed in all the wounds, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. The artificial dermis was transparent but not well connected with the wound. On PID 7, the new infection rate of control wounds was 20.00% (6/30), which was obviously higher than 3.33% (1/30) of disinfectant wounds, χ(2)=4.043, P<0.05. On the infected wound, a large amount of purulent exudates were observed, and the artificial dermis was not connected with the wound and degraded partially. On the uninfected wound, artificial dermis was transparent and had a partial connection with the wound. On PID 14 and 21, no new infected wound was observed, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. There was no obvious improvement on the infected wounds. The collagen layers of artificial dermis in the uninfected wound established a good connection with the wound and were separating from the silica gel layer gradually. Infection occurred in 2, 3, 1 control wound (s) in PID 7, 14, and 21 sampling groups, respectively, and in 1 disinfectant wound in PID 14 sampling group. The bacteria content of the infected wounds tissue was 0.79×10(6) to 7.22×10(9) colony-forming unit (CFU)/g. The bacteria content of uninfected control wounds tissue in PID 3, 7, and 14 sampling groups were (3.43±1.88)×10(2,) (2.37±0.43)×10(3,) and (8.40±1.03)×10(3) CFU/g, respectively, which were significantly higher than (0.33±0.12)×10(2,) (0.43±0.17)×10(3,) (2.16±0.52)×10(3) CFU/g of uninfected disinfectant wounds tissue (Z=-3.780, -3.554, -3.334, P<0.05). The bacteria content of uninfected control wounds tissue and that of uninfected disinfectant wounds tissue in PID 21 sampling group were similar (Z=-0.490, P>0.05). Conclusions: Compound lysostaphin disinfectant has quite strong antibacterial ability against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus. Clinical strains of the three kinds of bacteria were highly sensitive to compound lysostaphin disinfectant. Saturation of absorption of compound lysostaphin disinfectant achieves in artificial dermis after 2 hours' soaking. After 24, 36, and 48 hours' standing, the soaked artificial dermis still has the antibacterial effect on Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, respectively. The infection rate and the bacteria content of full-thickness skin defect wound in rats are all decreased when grafted with soaked artificial dermis.

[Preparation of bioactive denatured acellular dermal matrix from burn mice riched in mice bone marrow mesenchymal stem cells].

Objective: To investigate the preparation of bioactive denatured acellular dermal matrix (DADM) from burn mice riched in mice bone marrow mesenchymal stem cells. Methods: Twelve BALB/c mice were collected and 20% total body surface area scalds (hereinafter referred to as burns) with deep partial thickness were inflicted on the back skin of each mouse. After removing epidermis, the burned skin were collected and divided into Triton X-100 group and elhylene diamine tetraacetic acid (EDTA) group according to the random number table, with 15 samples in each group. Samples in Triton X-100 group and EDTA group were respectively placed in mixture of 2.5 g/L Triton X-100 and 2.5 g/L trypsin solution and mixture of 0.2 g/L EDTA and 2.5 g/L trypsin solution for sustained vibration and elution for 24 hours to make mice DADM. The general appearance of DADM was observed. The structure and arrangement of collagen fibers of DADM were observed by scanning electron microscope and tissue structure of DADM were observed by fluorescence microscope. Bone marrow mesenchymal stem cells (BMSCs) from mice were transplanted in mice DADM in the two groups with concentration of 2×105 cells per well to prepare bioactive mice DADM. After cultured for 3 days, tissue structure of bioactive mice DADM was observed by hematoxylin and eosin staining, distribution and number of BMSCs of bioactive mice DADM were observed by immunofluorescence staining. Proliferation of BMSCs of bioactive mice DADM after cultured for 2 h, 1 d, 3 d, and 5 d was detected by cell count kit-8. Data were processed with analysis of variance for repeated measurement and t test. Results: (1) Mice DADM in the two groups were white in appearance with certain tenacity and elasticity. Mice DADM in the two groups maintained good three-dimensional porous network structure. Collagen fibers of mice DADM in EDTA group were with good continuity, and collagen fibers of mice DADM in Triton X-100 group were fractured in varying degrees. Mice DADM in the two groups were decellularized completely, and the collagen fibers were loose and arranged disorderly. The continuity of tissue structure of mice DADM in EDTA group was better than that of mice DADM in Triton X-100 group. (2) After cultured for 3 days, the BMSCs in bioactive mice DADM in the two groups were evenly distributed. The number of bioactive BMSCs in mice DADM in EDTA group was 37±7, which was significantly more than that of mice DADM in Triton X-100 group (25±8, t=0.128, P<0.05). The proliferation of bioactive BMSCs in mice DADM in Triton X-100 group and EDTA group was similar at 2 hours and on day 1 after cultured (t=1.292, 0.656, P>0.05). On 3, 5 days after cultured, the proliferation of bioactive BMSCs in mice DADM in EDTA group was significantly higher than that of mice DADM in Triton X-100 group (t=2.309, 14.128, P<0.05 or P<0.01). Conclusions: Mice DADM prepared by decellularization of EDTA has better three-dimensional porous network structure and good continuity of collagen fiber. The BMSCs in bioactive DADM from burn mice prepared by transplanting BMSCs are evenly distributed with large quantity and strong proliferative capacity, which has the potential to be good autologous dermal substitute.

Manejo de defeitos complexos do couro cabeludo após excisão de tumores malignos / Management of complex scalp defects after excision of malignant tumors

Introdução: A reconstrução do couro cabeludo após a ressecção oncológica continua sendo um desafio para o cirurgião, especialmente considerando a incidência crescente de câncer de pele entre pacientes idosos. A matriz dérmica (MD) é um grupo heterogêneo de materiais de cobertura de feridas que auxiliam no fechamento da ferida e substituem algumas das funções da pele, temporária ou permanentemente. Pacientes com maior risco cirúrgico podem se beneficiar do uso de MD, que ajuda a gerar uma nova derme, oferecendo grandes melhorias na cobertura de defeitos complexos e extensos. Métodos: É um trabalho retrospectivo com análise de prontuário e relato de dois casos de pacientes do A.C.Camargo Cancer Center-SP, Brasil. Resultados: Relatamos dois casos de defeitos complexos e extensos de couro cabeludo em um centro único usando MD associada a enxerto cutâneo e terapia de pressão negativa (TPN) na cirurgia reconstrutiva após ressecção de neoplasia maligna da pele com resultados funcionais e estético satisfatório. Conclusões: As lesões extensas do couro cabeludo são um desafio na prática clínica e um tratamento multidisciplinar é fundamental. Os resultados obtidos indicam que a MD associada com a enxertia de pele parcial e com a TPN tem enorme potencial para aumentar as opções terapêuticas disponíveis para o cirurgião e possivelmente beneficiando os pacientes, especialmente aqueles que não têm condições clínicas para uma cirurgia extensa de cobertura com retalho microcirúrgico.

Introduction: Scalp reconstruction after cancer resection remains a challenge for surgeons, especially considering the increasing incidence of skin cancer among elderly patients. Dermal matrix (DM) is a heterogeneous group of wound covering materials that aid in wound closure and replace some of the skins functions, either temporarily or permanently. Patients at higher surgical risk can benefit from the use of DM, which help to generate a new dermis, offering great improvements in coverage of complex and extensive defects Methods: It is a retrospective study with analysis of medical records and report of two cases of patients at the A.C.Camargo Cancer Center-SP, Brazil. Results: We report two cases of complex and extensive scalp defects at a single center using DM associated with skin grafting and negative pressure therapy (NPT) in reconstructive surgery after resection of malignant skin neoplasm with satisfactory functional and esthetic results. Conclusions: Extensive lesions of the scalp are a challenge in clinical practice and a multidisciplinary treatment is essential. The results obtained indicate that DM associated with partial skin grafting and NPT have enormous potential to increase the therapeutic options available to the surgeon and possibly benefit patients, especially those who do not have the clinical conditions for extensive coverage surgery with microsurgical flap.

Análise do uso de matriz de regeneração dérmica em crianças / Analysis of the use of dermal regeneration matrix in children

OBJETIVO: Analisar as utilizações e do desfecho imediato da MRD Integra® no fechamento cutâneo de lesões extensas em crianças atendidas no serviço de Cirurgia Pediátrica do Hospital Infantil Joana de Gusmão no período de janeiro de 2002 a dezembro de 2017. MÉTODO: Trata-se de um estudo retrospectivo, analítico e vertical que avaliou os arquivos de todas as crianças submetidas a aplicação de MRD no período de janeiro de 2002 a dezembro de 2017, totalizando 155 pacientes. RESULTADOS: Foram analisados 155 pacientes submetidos ao implante de MRD, totalizando 191 implantes. A maioria dos pacientes era do sexo masculino (58,06%) e pré-púberes (32,02%). Os diagnósticos mais prevalentes foram queimadura em fase aguda (35,97%), retração cicatricial (32,8%) e retração cicatricial e cicatriz hipertrófica (14,28%). A pega total do implante foi observada em 68,42% dos pacientes, numa média de 19,16 dias. O número de implantes submetidos ao tratamento conjunto com curativos de pressão negativa (CPN) foi de 86 (46,24%). A porcentagem média de pega parcial foi de 82,30%. Dos 191 implantes, 58 tiveram complicações (30,36%). CONCLUSÕES: As MRD são uma opção atual para cobertura cutânea em crianças, com utilizações diversas, taxa aceitável de complicações e bom resultado imediato.

OBJECTIVE: To analyze the uses and the immediate outcome of MRD Integra® in the cutaneous closure of extensive lesions in children seen at the Pediatric Surgery service of Hospital Infantil Joana de Gusmão from January 2002 to December 2017. METHODS: This is a retrospective, analytical and vertical study that evaluated the files of all children submitted to the application of MRD from January 2002 to December 2017, totaling 155 patients. RESULTS: 155 patients submitted to MRD implantation were analyzed, totaling 191 implants. Most patients were male (58.06%) and prepubertal (32.02%). The most prevalent diagnoses were acute burns (35.97%), scar retraction (32.8%) and scar retraction and hypertrophic scarring (14.28%). Total implant take-up was observed in 68.42% of patients, with an average of 19.16 days. The number of implants submitted to joint treatment with negative pressure dressings (CPN) was 86 (46.24%). The average percentage of partial catch was 82.30%. Of the 191 implants, 58 had complications (30.36%). CONCLUSIONS: MRDs are a current option for skin coverage in children, with different uses, an acceptable rate of complications and a good immediate result.

The use of matriderm and autologous skin graft in the treatment of full thickness skin defects.

BACKGROUND: For patients with full thickness skin defects, autologous Split-thickness skin grafts (STSG) are generally regarded as the mainstay of treatment. However, skin grafts have some limitations, including undesirable outcomes resulting from scars, poor elasticity, and limitations in joint movement due to contractures. In this study, we present outcomes of Matriderm grafts used for various skin tissue defects whether it improves on these drawbacks. METHODS: From January 2010 to March 2012, a retrospective review of patients who had undergone autologous STSG with Matriderm was performed. We assessed graft survival to evaluate the effectiveness of Matriderm. We also evaluated skin quality using a Cutometer, Corneometer, Tewameter, or Mexameter, approximately 12 months after surgery. RESULTS: A total of 31 patients underwent STSG with Matriderm during the study period. The success rate of skin grafting was 96.7%. The elasticity value of the portion on which Matriderm was applied was 0.765 (range, 0.635-0.800), the value of the trans-epidermal water loss (TEWL) was 10.0 (range, 8.15-11.00) g/hr/m(2), and the humidification value was 24.0 (range, 15.5-30.0). The levels of erythema and melanin were 352.0 arbitrary unit (AU) (range, 299.25-402.75 AU) and 211.0 AU (range, 158.25-297.00 AU), respectively. When comparing the values of elasticity and TEWL of the skin treated with Matriderm to the values of the surrounding skin, there was no statistically significant difference between the groups. CONCLUSIONS: The results of this study demonstrate that a dermal substitute (Matriderm) with STSG was adopted stably and with minimal complications. Furthermore, comparing Matriderm grafted skin to normal skin using Cutometer, Matriderm proved valuable in restoring skin elasticity and the skin barrier.

Tratamento pediátrico de grande queimado agudo: Manejo clínico, cirúrgico e uso de matriz de regeneração dérmica / Pediatric treatment of large acute burn: Clinical, surgical management and use of dermal regeneration matrix / Tratamiento pediátrico de gran quemado agudo: Manejo clínico, quirúrgico y uso de matriz de regeneración dérmica

Objetivo: Analisar o tratamento de queimaduras em fase aguda, conduta clínica, cirúrgica e uso de matriz de regeneração dérmica (MRD) em criança internada na Unidade de Queimados do Hospital Regional da Asa Norte (UQ-HRAN), Brasília-DF. Relato do Caso: D.M.R., 2 anos e 7 meses, masculino, vítima de queimadura por chama direta, 60% de superfície corporal acometida, 50% sendo de espessura total. Atendido inicialmente segundo Protocolo de Rotinas da UQ-HRAN, entretanto, evoluiu com piora clínica, necessitando de Unidade de Terapia Intensiva pediátrica, por 58 dias. Neste período, foi submetido a 2 escarotomias, 3 desbridamentos e 10 hemotransfusões, apresentou infecções nas áreas queimadas e variados esquemas antibióticos. Tendo em vista a extensão de áreas acometidas, restrição de áreas doadoras viáveis e impossibilidade de outros curativos, optou-se pelo implante de MRD no 16° dia de internação e, após a integração, foram realizadas 6 enxertias cutâneas. Recebeu alta no 118° dia de internação. Conclusão: Houve necessidade de assistência clínica e cuidados intensivos, além de utilização de técnica cirúrgica com implante de MRD em grande queimado agudo. Sendo assim, a MRD teve como objetivo proporcionar leito receptor de qualidade, associado a maior integração para enxertia cutânea futura, pois a carência de áreas doadoras o colocaria em risco de vida maior. Esse conjunto de fatores contribuiu para o sucesso do tratamento e a boa recuperação da criança.

Objective: To analyze the treatment of burn in acute-phase using clinical, surgical management and use of dermal regeneration matrix (DRM) in a child hospitalized at the Burn Unit of Asa Norte Regional Hospital (BU-ANRH), Brasília-DF. Case Report: D.M.R., 2 years and 7 months old, male, victim of direct fire, 60% of body surface affected, 50% full-thickness. Initially treated according to the BU-ANRH Routine Protocol, however, evolved to clinical decline, requiring a pediatric Intensive Care Therapy for 58 days. During this period, he underwent two escharotomies, three debridements and 10 blood transfusions. He exhibited infection in burned areas and used multiple antibiotic schemes. Due to the extension of affected surface, restriction of viable donor zone and unusable of other bandages, DRM was implanted on the 16th day of hospitalization and integration, he has done six cutaneous grafting. He was discharged on the 118th day of hospitalization. Conclusion: Clinical and intensive care were needed, besides the use of surgical technique with DRM implantation in a large acute burn. Thus, DRM has had as a goal to provide quality receptor bed, associated with greater integration for future cutaneous grafting, since the lack of donor areas would put it at greater risk of life. This set of factors contributed to the success of the treatment and the good recovery of the child.

Objetivo: Analizar el tratamiento de quemaduras en fase aguda, conducta médica clínica, quirúrgica y uso de matriz de regeneración dérmica (MRD) en niño internado en la Unidad de Quemados del Hospital Regional de Asa Norte (UQ-HRAN), Brasília-DF. Reporte de Caso: D.M.R., 2 años y 7 meses, masculino, víctima de quemadura de llama directa, 60% de la superficie del cuerpo afectada, 50% del espesor total. Inicialmente tratado de acuerdo con el Protocolo de Rutina UQ-HRAN, sin embargo, evolucionó con un empeoramiento clínico, necesitando cuidados en la Unidad de Terapia Intensiva pediátrica durante 58 días. Durante este período, fue sometido a 2 escarotomías, 3 desbridamientos y 10 transfusiones de sangre. Presentó infecciones en zonas quemadas y variados esquemas antibióticos. Debido a la extensión de las áreas afectadas, la restricción de las áreas viables de los donantes y la imposibilidad de otros curativos, se optó por el implante de MRD en el 16° día de internación y después de la integración, se realizaron 6 injertos cutáneos. Recibió alta en el 118° día de internación. Conclusión: Hubo necesidad de asistencia clínica y cuidados intensivos, además de utilización de técnica quirúrgica con implante de MRD en gran quemado agudo. Por lo tanto, la MRD tuvo como objetivo proporcionar lecho receptor de calidad, asociado a la mayor integración para el injerto cutáneo futuro, pues la carencia de áreas donantes lo pondría en mayor riesgo de vida. Este conjunto de factores, contribuyó al éxito del tratamiento y la buena recuperación del niño.

Particular catastrophic antiphospholipid syndrome, on the sole surgical site after breast reduction.

A 20-year-old woman treated with vitamin K antagonist for antiphospholipid syndrome (APS) (pulmonary embolisms at age 15) was admitted for breast reduction after bridging therapy. At 2 days post-surgery haematomas appeared on the surgical site and anticoagulant therapy was withheld. She developed a skin and breast necrosis leading to the diagnosis of catastrophic APS. Despite medical treatment (anticoagulant therapy, corticosteroids and intravenous immunoglobulins) and surgery, necrosis continued. After 2 weeks of negative-pressure wound therapy (V.A.C.(®) Therapy™) the patient improved, mammary tissues were alive, well vascularised and budding. Breast reconstruction was then initiated. Artificial dermis graft (MatriDerm(®) 2 mm) was applied, and 3 weeks later the apposition of split-thickness skin graft on it. Six months later, results of the surgery were good and the patient was satisfied.

Uso da matriz de regeneração dérmica em retração cicatricial por queimadura: Relato de caso / The use of template dermal regeneration in burn scar contraction: Case report

OBJETIVO: A ausência de áreas doadoras suficientes ou apresentando má qualidade para o tratamento de retração cicatricial após queimaduras determina muitas vezes resultados insatisfatórios. Nesse contexto, surgiram as matrizes de regeneração dérmica - e entre elas encontra-se o Integra®. Este estudo discute as aplicações desse substituto dérmico à luz de um caso de retraçao cicatricial significativa. MÉTODO: Relato de caso. Paciente feminino, 43 anos, sofreu na infância queimadura da região cervical, tronco e membros superiores com querosene. Apresentou retração cicatricial grave, procurando auxílio médico 29 anos após o acidente. Foi submetida à ressecção da contratura cicatricial, sendo utilizada matriz de regeneração dérmica e posterior enxertia de pele parcial autóloga. RESULTADOS: Não houve complicações após os dois procedimentos cirúrgicos. O tempo de internação foi de 30 dias. O seguimento de 48 meses. Retração cicatricial recorrente foi observada, porém menor que a apresentada previamente pela paciente e sem prejuízo funcional. CONCLUSOES: O uso da matriz dérmica é uma excelente opção para o tratamento da retração cicatricial. A indicação clássica do seu uso é em uma área de cicatriz, com ou sem contratura, abrangendo qualquer local do corpo onde as técnicas de expansão e/ou retalho tecidual não podem resolver o problema, seja por causa da localização, escassez de pele saudável, ou tamanho da lesão.

OBJECTIVE: The absence of sufficient donor areas or having poor quality for the treatment of scar retraction after burns often determine unsatisfactory results. In this context emerged the matrix of dermal regeneration - and between them lies the Integra®. This study discusses the applications of dermal substitute in the light of a case of significant scar retraction. METHOD: Case report. Female patient, 43, suffered burns in childhood neck, trunk and upper limbs with kerosene. Had severe scar retraction, seeking medical attention 29 years after the accident. It underwent resection of scar contracture, being used dermal regeneration matrix and subsequent grafting autologous partial skin. RESULTS: There were no complications after the two surgical procedures. The length of stay was 30 days. The follow-up of 48 months. Recurring scar retraction was observed, but less than previously presented by the patient and without functional impairment. CONCLUSIONS: The use of the dermal matrix is an excellent option for the treatment of scar retraction. The classic indication of use is in a scarred area, with or without contracture, covering anywhere on the body where the expansion of technical and/or tissue flap can not solve the problem either because of the location, healthy skin shortage, or lesion size.

Substitutos cutâneos: conceitos atuais e proposta de classificação / Skin substitutes: current concepts and a new classification system

Feridas complexas podem resultar na perda completa do revestimento cutâneo. A solução consagrada pela cirurgia plástica é a enxertia de pele autógena, porém há casos em que ocorre escassez de área doadora cutânea, um problema ainda não totalmente solucionado. Assim, atualmente há muito interesse por materiais sintéticos ou biológicos que possam ser utilizados como substitutos cutâneos. O objetivo deste estudo foi introduzir uma forma mais didática de agrupar diferentes tipos de substitutos cutâneos. Acreditamos que esses produtos podem ser classificados de forma mais abrangente se forem divididos segundo três critérios: camada substituída da pele, subdivididos em epidérmicos (E), dérmicos (D) e compostos dermoepidérmicos (C); duração no leito da ferida, subdivididos em temporários (T) e permanentes (P); e origem do material constituinte, subdivididos em biológicos (b), biossintéticos (bs) e sintéticos (s).

Complex wounds are characterized by complete loss of cutaneous cover. The most common plastic surgery technique is the autogenous skin graft; however, the amount of material available from donor areas is often limited. The development of synthetic or biological products as skin substitutes is therefore an area of interest. The present study aimed to classify the different types of skin substitutes available based on three criteria: the skin layer to be replaced, which can be categorized into epidermal (E), dermal (D), and dermal-epidermal composites (C); the durability in the wound bed, which can be temporary (T) or permanent (P); and the origin of the material, subdivided into biological (b), biosynthetic (bs), and synthetic (s).