Microskin autografting in the treatment of burns over 70% of total body surface area: 14 years of clinical experience

Outcome comparison of the most commonly employed wound coverage techniques in patients with massive burns ≥50% TBSA - A systematic review and meta-analysis

INTRODUCTION

Early wound coverage is one of the most essential factors influencing the survival of extensively burned patients, especially those with a total body surface area (TBSA) burned greater than 50 %. In patients with limited donor sites available for autografting, techniques such as the Meek micrograft procedure or cultured epidermal allografts (CEA) have proven to be viable alternatives. In this systematic review and meta-analysis, we analyzed the outcomes of different wound coverage techniques in patients with massive burn injuries ≥ 50 % TBSA in the past 17 years.

METHODS

The EMBASE, PUBMED, Google Scholar and MEDLINE databases were searched from inception to December 2022 for studies investigating major burn reconstruction (>50 % TBSA) with the use of one of: a) autografts, b) allografts, c) cell-based therapies, and d) Meek micrografting. The review was conducted in accordance with the PRISMA guidelines. The outcomes evaluated were mortality, length of hospital stay, graft take and number of operations performed.

RESULTS

Following a two-stage review process, 30 studies with 1369 patients were identified for analysis. Methods of coverage comprised the original autografting, and the newer Meek micrografting, CEA autografting, and allografting. Pooled mean age of the entire cohort was 32.5 years ( ± SE 3.6) with mean burn size of 66.1 % ( ± 2.5). After pooling the data, advantages in terms of mortality rate, length of stay, graft take and number of required surgeries were seen for the Meek and CEA groups. Mortality was highest in patients treated with autografts (50 %) and lowest with cell-based therapy (11 %). Length of stay was longest with cell-based therapy (91 ± 16 days) and shortest with Meek micrografting (50 ± 24 days). Graft take was highest with autografts (96 ± 2 %) and lowest with cell-based therapy (72 ± 9 %). Average number of operations was highest with cell-based therapy (9 ± 4) and lowest with Meek micrografting (4 ± 2).

CONCLUSIONS

Comparison of the four techniques highlighted differences in terms of all outcomes assessed, and each technique was associated with different advantages. Interestingly autografting, the option with the highest graft take rate, was also associated with the highest mortality. This study not only serves to provide the first comparison of the most commonly used techniques in major burn reconstruction, but also highlights the need for prospective studies that directly compare the efficacy of the different techniques to ultimately establish whether a true superior option exists.

Repair of pressure ulcers in the elderly using autologous microskin implantation and negative pressure wound therapy: A retrospective study

BACKGROUND

Pressure ulcers remain a worldwide problem.

OBJECTIVE

To introduce an intermittent and feasible wound treatment method for the treatment of pressure ulcers in elderly patients.

METHODS

This surgical procedure was performed on eight elderly patients suffering from pressure ulcers. Microskin measuring 0.1 × 0.1 centimeters was cut from a small amount of thin skin and then grafted onto the wound surface in conjunction with closed negative pressure therapy.

RESULTS

Seven patients had their wounds closed after a single surgery, while one patient required two surgeries to close the wound.

CONCLUSION

Autologous microskin implantation for the treatment of pressure ulcers in the elderly is an effective method to close the wound, which can prevent the elderly from living with wounds in their later years and is a viable treatment option.

Diagnostic value of procalcitonin and red blood cell distribution width at admission on the prognosis of patients with severe burns: A retrospective analysis

The plasma procalcitonin (PCT) concentration and red blood cell distribution (RDW) value after severe burns can be used as prognostic indicators, but at present, it is difficult to give consideration to sensitivity and specificity in diagnosing the prognosis of severe burns with a single indicator. This study analysed the diagnostic value of plasma PCT concentration and RDW value at admission on the prognosis of severe burn patients to improve its sensitivity and specificity. A total of 205 patients with severe burns who were treated in the First Affiliated Hospital of Anhui Medical University from November 2017 to November 2022 were retrospectively analysed. The optimal cut-off values of plasma PCT concentration and RDW were analysed and counted through the subject curve (ROC curve). According to the cut-off value, patients were divided into high PCT group and low PCT group, high RDW group and low RDW group. The independent risk factors of severe burns were analysed by single-factor and multiple-factor COX regression. Kaplan-Meier survival was used to analyse the mortality of high PCT group and low PCT group, high RDW group and low RDW group. The area under the curve of plasma PCT concentration and RDW value at admission was 0.761 (95% CI, 0.662-0.860, P < .001), 0.687 (95% CI, 0.554-0.820, P = .003) respectively, and the optimal cut-off values of serum PCT concentration and RDW were 2.775 ng/mL and 14.55% respectively. Cox regression analysis found that age, TBSA, and RDW were independent risk factors for mortality within 90 days after severe burns. Kaplan-Meier survival analysis showed that there was a significant difference in the 90-day mortality rate of severe burns between the PCT ≥ 2.775 ng/mL group and the PCT < 2.775 ng/mL group (log-rank: 24.162; P < .001), with the mortality rate of 36.84% versus 5.49%, respectively. The 90-day mortality rate of severe burns was significantly different between the RDW ≥ 14.55% group and the RDW < 14.55% group (log-rank: 14.404; P < .001), with the mortality rate of 44% versus 12.2% respectively. The plasma PCT concentration and RDW value at admission are both of diagnostic value for the 90-day mortality of severe burns, but the plasma PCT concentration has higher sensitivity and the RDW value has higher specificity. Age, TBSA, and RDW were independent risk factors for severe burns, and then plasma PCT concentration was not independent risk factors.

Plasma Neutrophil-to-Lymphocyte Ratio on the Third Day Postburn is Associated with 90-Day Mortality Among Patients with Burns Over 30% of Total Body Surface Area in Two Chinese Burns Centers

INTRODUCTION

Neutrophil-to-lymphocyte ratio (NLR) is a marker of inflammation. This study aimed to evaluate the potential role of NLR to predict 90-day mortality.

METHODS

Data of 577 patients with burns over 30% of total body surface area were collected and retrospectively analyzed. The risk factors for 90-day mortality were evaluated using logistic regression analyses. Receiver operating characteristic (ROC) curve analysis of the 3rd day NLR was performed and the optimal cut-off value was calculated. The 90-day mortality rates were compared between high and low NLR groups using Kaplan-Meier analysis.

RESULTS

Age, mechanical ventilation, burn index, 3rd day NLR, and 7th day red blood cell and platelet (PLT) counts were found to be independent predictive values for 90-day mortality. In contrast, percentage of total body surface area burned, inhalation injury, 1st day white blood cell and neutrophil counts, the 3rd day lymphocytes and PLT counts, and 7th day hemoglobin level were not independently associated with 90-day mortality. The area under the ROC curve of the 3rd day NLR for severe burn-delayed death prediction was 0.665 (95% confidence interval, 0.591-0.739), and the optimal cut-off value of the 3rd day NLR was 10.50. The 90-day mortality rates differed significantly between the NLR >10.5 group and the NLR ≤ 10.5 group (17.03% vs 5.92%, respectively; P < 0.01).

CONCLUSION

These results suggested that the 3rd day NLR was associated with an increased risk of death in severely burned patients; thus, it can provide useful information to predict 90-day mortality.

Autograft microskin combined with adipose-derived stem cell enhances wound healing in a full-thickness skin defect mouse model

OBJECTIVE

Autograft microskin transplantation has been widely used as a skin graft therapy in full-thickness skin defect. However, skin grafting failure can lead to a pathological delay wound healing due to a poor vascularization bed. Considering the active role of adipose-derived stem cell (ADSC) in promoting angiogenesis, we intend to investigate the efficacy of autograft microskin combined with ADSC transplantation for facilitating wound healing in a full-thickness skin defect mouse model.

MATERIAL AND METHODS

An in vivo full-thickness skin defect mouse model was used to evaluate the contribution of transplantation microskin and ADSC in wound healing. The angiogenesis was detected by immunohistochemistry staining. In vitro paracrine signaling pathway was evaluated by protein array and Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway, and protein-protein interaction network analysis.

RESULTS

Co-transplantation of microskin and ADSC potentiated the wound healing with better epithelization, smaller scar thickness, and higher angiogenesis (CD31) in the subcutaneous layer. We found both EGF and VEGF cytokines were secreted by microskin in vitro. Additionally, secretome proteomic analysis in a co-culture system of microskin and ADSC revealed that ADSC could secrete a wide range of important molecules to form a reacting network with microskin, including VEGF, IL-6, EGF, uPAR, MCP-3, G-CSF, and Tie-2, which most likely supported the angiogenesis effect as observed.

CONCLUSION

Overall, we concluded that the use of ADSC partially modulates microskin function and enhances wound healing by promoting angiogenesis in a full-thickness skin defect mouse model.

Bacterial cellulose membrane used as biological dressings on third-degree burns in rats

INTRODUCTION

Burn injuries represent a high risk of morbidity and mortality. The wound healing process is complex and requires the participation of different types of cells. Therefore, new biomaterials, which innovate the wound healing process, are being investigated.

OBJECTIVE

The aim of this study was to investigate the use of bacterial cellulose both in its pure state and enriched with lidocaine in full-thickness burns in rats.

METHODS

Thirty rats (Wistar) (260 ± 20 gramas) divided into control group (CG), bacterial cellulose membrane group (MG) and bacterial cellulose membrane enriched with lidocaine group (MLG) were used. The burns were induced using a 150°C heated soldering iron, held on the animal neck for 10 seconds. The biomaterial was applied immediately after injury and skin samples were collected on the tenth day of the treatment. The level of significance of p⩽0.05 was used for the conclusion of the statistical analysis.

RESULTS

The groups treated with the biomaterials, a histological pattern compatible with a more advanced repair stage showing skin appendages, mild inflammatory infiltrate, better collagen fiber organization and mild immunostaining COX-2 and MMP-9 was observed, when compared to the control group that did not receive any type of treatment.

CONCLUSION

Thus, was concluded that the bacterial cellulose-based biomaterial both in its pure state and enriched with lidocaine optimizing the full-thickness burn wound healing in rats.

The Benefit of Microskin in Combination With Autologous Keratinocyte Suspension to Treat Full Skin Loss In Vivo

Patients with extensive deep burns often lack enough autologous skin to cover the wounds. This study explores a new method using microskin in combination with autologous keratinocytes in the treatment of extensive deep burn. Wounds in the combination group were treated with automicroskin at an area expansion ratio of 20:1 (wound area to automicroskin area) and autologous keratinocyte suspension, which were compared with the following treatments: no autotransplant, only allografts (control group); autologous keratinocyte suspension only (keratinocyte only group); automicroskin at an area expansion ratio of 20:1 (20:1 group); and automicroskin at an area expansion ratio of 10:1 (10:1 group, positive control). The authors used epithelialization rate (epithelialized area on day 21 divided by original wound area), hematoxylin and eosin staining, laminin, and type IV collagen immunohistochemistry to assess wound healing. The epithelialization rate of combination group (74.2% ± 8.0%) was similar to that of 10: 1 group (84.3% ± 11.9%, P = .085) and significantly (P < .05) higher than that of 20:1 group (59.2% ± 10.8%), keratinocyte only group (53.8% ± 11.5%), and control group (22.7% ± 5.5%). The hematoxylin and eosin staining and immunohistochemistry showed the epithelialization in the combination group was better than that in the keratinocyte only group and control group. Microskin in combination with autologous keratinocyte suspension can promote the reepithelialization of full-thickness wounds and reduce the requirements for automircoskin, and it is a useful option in the treatment of extensive deep burns.

Electrospinning: An enabling nanotechnology platform for drug delivery and regenerative medicine

Electrospinning provides an enabling nanotechnology platform for generating a rich variety of novel structured materials in many biomedical applications including drug delivery, biosensing, tissue engineering, and regenerative medicine. In this review article, we begin with a thorough discussion on the method of producing 1D, 2D, and 3D electrospun nanofiber materials. In particular, we emphasize on how the 3D printing technology can contribute to the improvement of traditional electrospinning technology for the fabrication of 3D electrospun nanofiber materials as drug delivery devices/implants, scaffolds or living tissue constructs. We then highlight several notable examples of electrospun nanofiber materials in specific biomedical applications including cancer therapy, guiding cellular responses, engineering in vitro 3D tissue models, and tissue regeneration. Finally, we finish with conclusions and future perspectives of electrospun nanofiber materials for drug delivery and regenerative medicine.

Prognostic values of red blood cell distribution width, platelet count, and red cell distribution width-to-platelet ratio for severe burn injury

Red blood cell distribution width (RDW), platelet count (PLT), and a RDW-to-PLT ratio (RPR) have been associated with inflammatory activity and adverse outcomes in many diseases. This study has aimed to investigate the association between these indicators and the mortality rate of severe burn patients. From 2008 to 2014, 610 cases of severe burn patients from two burn centers in eastern China were enrolled in this study. Eighty-eight patients died within 90 days after admission. The RDW, PLT, and RPR were studied through Cox regression analysis on the 3rd and 7th day. The RDW, PLT, and RPR values on the 3rd and 7th day were significantly associated with the outcomes of severe burn patients (P < 0.01). High RPR was significantly associated with a 90-day mortality rate at the two time points. However, the RDW and PLT did not provide independent predictive values. Our results indicated that the RPR values on the 3rd and 7th day were associated with the mortality rates of severe burn patients (P < 0.01). Meanwhile, the RDW and PLT values at these time points failed to provide independent values for burn mortality prediction. Thus, the RPR can serve as an independent and novel marker for mortality rates prediction in severe burn patients.

Experience and efficacy of surgery for retaining viable subcutaneous tissue in extensive full-thickness burns

BACKGROUND AND AIM

For adult patients with extensive full-thickness burns (EFTB), a fascial excision is mostly used but it causes a very significant deformity. This study aims to summarize experience and efficacy of surgery for retaining viable subcutaneous tissue in EFTB.

METHOD

Clinical data were reviewed for 31 consecutive adult patients with full-thickness burn (FTB) over 70% total body surface area (TBSA) and undergoing first tangential excision and skin grafting on subcutaneous tissue wound (TESGSTW) within 7 days post burn at our burn center between 2002 and 2013.

RESULTS

Average age, total burn area, and FTB area of 31 patients were 32.4 ± 12.8 years, 89.0 ± 6.2% and 80.4 ± 7.6% TBSA, respectively. Of these, 80.6% combined with inhalation injury and 71.0% supervened early shock. Eighteen patients who survived (58.1%) totally underwent 121 times of surgery, of which TESGSTW and autologous skin grafting were 41 and 88 times, respectively. Their average time and area of first tangential excision was 4.1 ± 0.6 days post burn and 33.8 ± 7.6% TBSA, respectively, and accumulated tangential excision area was 58.4 ± 10.8% TBSA. In 39 times of TESGSTW within 14 days post burn, cryopreserved alloskin or fresh young pigskin was applied on 84.6%, and average time and take rate of autologous skin grafting instead of grafted alloskin or xenoskin was 14.6 ± 0.7 days and 89.5 ± 1.4%, respectively. Scalp was the main donor site for autologous skin, especially microskin grafting. Systemic wound healing time roughly was 67.3 ± 1.9 days post burn, meanwhile, viable subcutaneous tissue was retained. Healed wounds were plump, and their extensibility and sensitivity were better by follow-up.

CONCLUSION

The surgical treatment in EFTB is practicable and effective.

Epidermal healing in burns: autologous keratinocyte transplantation as a standard procedure: update and perspective

Background:

Treatment of burned patients is a tricky clinical problem not only because of the extent of the physiologic abnormalities but also because of the limited area of normal skin available.

Methods:

Literature indexed in the National Center (PubMed) has been reviewed using combinations of key words (burns, children, skin graft, tissue engineering, and keratinocyte grafts). Articles investigating the association between burns and graft therapeutic modalities have been considered. Further literature has been obtained by analysis of references listed in reviewed articles.

Results:

Severe burns are conventionally treated with split-thickness skin autografts. However, there are usually not enough skin donor sites. For years, the question of how covering the wound surface became one of the major challenges in clinical research area and several procedures were proposed. The microskin graft is one of the oldest methods to cover extensive burns. This technique of skin expansion is efficient, but results remain inconsistent. An alternative is to graft cultured human epidermal keratinocytes. However, because of several complications and labor-intensive process of preparing grafts, the initial optimism for cultured epithelial autograft has gradually declined. In an effort to solve these drawbacks, isolated epithelial cells from selecting donor site were introduced in skin transplantation.

Conclusions:

Cell suspensions transplanted directly to the wound is an attractive process, removing the need for attachment to a membrane before transfer and avoiding one potential source of inefficiency. Choosing an optimal donor site containing cells with high proliferative capacity is essential for graft success in burns.

Sandwich-type fiber scaffolds with square arrayed microwells and nanostructured cues as microskin grafts for skin regeneration

The paper reports the fabrication of sandwich-type scaffolds consisting of radially-aligned nanofibers at the bottom, nanofiber membranes with square arrayed microwells and nanostructured cues at the top, and microskin tissues in between as microskin grafts for use in skin regeneration. This class of nanofiber scaffolds was able to confine the microskin tissues in the square arrayed wells and simultaneously present nanotopographic cues to the cultured NIH 3T3 fibroblasts and primary rat skin cells, guiding and facilitating their migration in vitro. More importantly, we demonstrated that the sandwich-type transplants exhibited an even distribution of microskin grafts, greatly improved the 'take' rate of microskin tissues, and promoted re-epithelialization on wound in vivo. In addition, the void area in the scaffolds was well suitable for exudate drainage in wound. The sandwich-type scaffolds show great potential as microskin grafts for repairing extensive burn injuries and may provide a good solution for the treatment of acute skin defects and chronic wounds including diabetic ulcer, pressure ulcer, and venous stasis ulcer.

A new method of microskin autografting with a Vaseline-based moisture dressing on granulation tissue

In the conventional method of microskin autografting, aggressive early excision is adopted, followed by coverage with a microskin-allograft complex to close extensive burn wounds. However, early excision is always associated with a defect of viable tissue, resulting in massive blood loss and causing high risk to aged patients or those with other systemic diseases. We developed a new method in which an eschar thinning operation was first adopted, followed by raising granulation tissue and microskin autografting, which was covered by a Vaseline-based moisture dressing. A total of 52 patients were included in this study and randomly assigned to the control group (n=26) and the experimental group (n=26) for the conventional method and the new method, respectively. The re-epithelisation rate on the 21st day after autografting indicated that there was no significant difference between both groups. There was also no significant difference between the two groups when the re-epithelialisation rate was compared with the type of organisms cultured. However, the Vancouver Burn Skin Score (VBSS) results demonstrated a significant improvement of cosmetic appearance in the experimental group (score=2.1) as compared to the control group (score=3.9). The new method also showed other advantages, including less blood loss, shorter surgical duration and lower cost of surgery. From this prospective study, it can be concluded that the new method can be an alternative to the conventional microskin autografting procedure.