Historical Evolution of Skin Grafting-A Journey through Time

Novel Techniques in Fractional Skin Replacement

The gold standards for coverage of wounds that cannot be primarily closed are full thickness skin grafts (FTSGs) and split thickness skins graft (STSGs). FTSGs harvest sites generally require primary closure, which limits availability, especially when treating larger wounds. STSGs have many shortcomings, including donor site morbidity. Fractional autologous skin replacement can be utilized in conjunction with or in lieu of STSGs to both improve graft outcomes of large wounds and to decrease donor site morbidity. Skin can be mechanically or chemically fractionated. Fractionated skin can be advantageous, as adnexal structures provide additional functionality without donor site morbidity. In this review, we will discuss current and emerging techniques in fractional skin replacement.

Strategies for Optimizing Acute Burn Wound Therapy: A Comprehensive Review

Recent advancements in acute burn wound therapy are transforming the management of burn injuries, with a focus on improving healing times, graft integration, and minimizing complications. However, current clinical treatments face significant challenges, including the difficulty of accurately assessing wound depth and tissue viability, which can lead to suboptimal treatment planning. Traditional closure methods often struggle with issues such as delayed wound closure, limited graft survival, inadequate tissue regeneration, and insufficient vascularization. Furthermore, managing infection and minimizing scarring remain persistent obstacles, impacting functional recovery and aesthetic outcomes. Key areas of innovation include advanced imaging techniques that enable more precise assessment of wound depth, size, and tissue viability, allowing for more accurate treatment planning. In addition, new closure strategies are being developed to accelerate wound closure, enhance graft survival, and address challenges such as tissue regeneration, vascularization, and infection prevention. These strategies aim to optimize both functional recovery and aesthetic outcomes, reducing scarring and improving the quality of life for burn patients. While promising, these emerging techniques require further research and clinical validation to refine their effectiveness and expand their accessibility. Together, these innovations represent a significant shift in acute burn care, offering the potential for more personalized, efficient, and effective treatments.

Expansion limits of meshed split-thickness skin grafts

Split-thickness skin grafts are widely used to treat chronic wounds. Procedure design requires surgeons to predict how much a patch of the patient's own skin expands when it is meshed with rows of slits and stretched over a larger wound area. Accurate prediction of graft expansion remains a challenge, with current models overestimating the actual expansion, leading to suboptimal outcomes. Inspired by the principles of mechanical metamaterials, we developed a model that distinguishes between the kinematic rearrangement of structural elements and their stretching, providing a more accurate prediction of skin graft expansion. Our model was validated against extensive data from skin graft surgeries, demonstrating vastly superior predictive capability compared to existing methods. This metamaterial-inspired approach enables informed decision-making for potentially improving healing outcomes. STATEMENT OF SIGNIFICANCE: Accurately predicting the expansion of meshed skin grafts is crucial for minimizing patient trauma and optimizing healing outcomes in reconstructive surgery. However, current quantitative models, which treat grafts as tessellated trusses of rigid bars, fail to accurately estimate graft expansion. We have uncovered the mechanisms underlying skin graft expansion and developed a straightforward method based on these findings. This method, designed for practical use by surgeons, provides accurate predictions of graft expansion, as validated against extensive data from skin graft surgeries.

Safety and effectiveness of micropigmentation skin grafting using the Meek method

The management of complex burn injuries has evolved significantly, with various surgical techniques developed to improve outcomes. This review examines the evolution of these methods, focusing particularly on mesh grafting and the Meek technique. While mesh grafting is effective, it poses challenges such as limited graft coverage and a high demand for autologous skin. In contrast, the Meek technique, a specialized method reintroduced in 1993, offers notable advantages for extensive burns by achieving higher skin expansion ratios of up to 1:9 and reducing the need for large donor sites. The Meek technique uses a meshing device to create tiny perforations in small skin grafts, facilitating their expansion to cover larger wound areas and improving healing outcomes. Recent studies highlight its effectiveness across various burn severities and age groups, especially when combined with Cultured Epithelial Autografts (CEA). Additionally, bioengineering advancements like Biobrane offer temporary skin substitutes to aid burn wound healing in pediatric cases, though they ultimately require replacement with autografts. While the Meek technique presents certain challenges, such as a 6-day delay before applying allografts, it remains a robust alternative to traditional methods. Clinical experience indicates that the Meek technique, particularly when combined with CEA, can achieve superior results for severe burns compared to conventional mesh grafting. This review emphasizes the Meek technique's potential as a valuable tool in burn wound management, offering a promising approach for improving patient outcomes in complex burn injuries.

Linked Flaps of the Thoracodorsal Vascular Tree for Correcting Extensive Post-Burn Deformities and Achieving Optimal Reconstruction Outcomes

BACKGROUND

Autologous skin grafting has been the popular method for reconstructing post-burn defects. However, this technique has limitations such as high contracture rates and inadequate volume coverage. This report aims to propose the principles and advantages of utilizing microsurgically linked perforator flaps for the reconstruction of extensive burn defects and associated post-burn scar contracture in the lower and upper extremities and trunk.

METHOD

Patients who underwent free tissue transfer for primary and secondary burn wound reconstruction at a single institution between 2016 and 2023 were included in the study. Patients received thoracodorsal vascular tree-linked flaps for the correction of post-burn deformities. Postoperative results were evaluated, including flap survival, complications, and the DASH self-report questionnaire for upper extremity reconstruction.

RESULT

Among the 20 patients, 12 required primary reconstruction, while 8 underwent secondary reconstruction using anastomotic chimeric free tissue transfer. The majority of burn injuries resulted from thermal contact (n = 8), followed by flames (n = 5), scalds (n = 4), electrical contact (n = 2), and friction (n = 1). The most frequently utilized combinations were the thoracodorsal artery perforator (TDAp) and anterolateral thigh (ALT) flap (11 cases). Additionally, four cases involved the pedicled TDAp flap in conjunction with the deep inferior epigastric artery perforator (DIEP) flap. The average DASH score for upper extremity burn patients was 10.58.

CONCLUSIONS

Three-dimensional tissue coverage achieved through the linkage of two or even three independent free flaps is increasingly utilized in post-burn reconstruction. This approach offers multiple advantages and represents a viable option for burn reconstruction.

An Update on Molecular Mechanisms of Scarring-A Narrative Review

Fibroblasts, the principal cellular mediators of connective tissue remodeling, play a crucial role in the formation of physiological and pathological scars. Understanding the intricate interplay between fibroblasts and other cellular and molecular components is essential for elucidating the underlying mechanisms driving scar formation. Hypertrophic scars, keloids and atrophic scars arise from dysregulated wound healing processes characterized by persistent inflammation, aberrant collagen deposition, and impaired extracellular matrix remodeling. Fibroblasts play a central role in the pathogenesis of such pathological scars, driving aberrant extracellular matrix remodeling, subsequently contributing to the formation of raised or depressed fibrotic lesions. The investigation of complex interactions between fibroblasts and the microenvironment is crucial for developing targeted therapeutic interventions aimed at modulating fibroblast activity and improving clinical outcomes in patients with pathological scars. Further research into the molecular pathways governing fibroblast behavior and their heterogeneity holds promise for advancing scar management strategies. This narrative review was performed to shed light on the mechanisms behind scar formation, with a special focus on the role of fibroblasts in the formation of different types of scars, providing insights into the pathophysiology of these conditions. Through the analysis of current knowledge, this review seeks to identify the key cellular and molecular mechanisms involved in fibroblast activation, collagen synthesis, and extracellular matrix remodeling in hypertrophic scar, keloid, or atrophic scar formation.

Multidisciplinary Management and Autologous Skin Grafting in a Patient with Severe Burns: A Case Study

Background: Heat burns are a prevalent type of trauma. Rapid and effective treatment is crucial for deep burns to minimize complications. Autologous skin grafting is a highly effective treatment for full-thickness burns. A multidisciplinary team plays a vital role in managing burn patients undergoing skin grafting, from initial contact to outpatient follow-up. Case Summary: This case study involves a 56-year-old patient who suffered burns on 60% of his body following an alcohol explosion on an open flame. The patient underwent autologous skin grafting at a Major Burn Center. Initial symptoms included severe pain and immobility, but the patient remained alert and breathed spontaneously. The diagnosis was a loss of epidermis and dermis with burns covering 60-69% of the total body surface area (TBSA) and third-degree burns covering 10% TBSA. Post-discharge, the patient showed significant improvement, with complete healing of the grafts and partial resolution of other lesions. Six months after the intervention, the patient significantly improved his autonomy and mobility. Conclusions: This case highlights the importance of burn prevention and the critical role of multidisciplinary teams in the entire care pathway of burn patients. Appropriate diagnosis, complete treatment, and continuous multidisciplinary support are essential to prevent complications and ensure recovery.

Perspective from developers: Tissue-engineered products for skin wound healing

Tissue-engineered products (TEPs) are at the forefront of developmental medicines, precisely where monoclonal antibodies and recombinant cytokines were 30 years ago. TEPs development for treating skin wounds has become a fast-growing field as it offers the potential to find novel therapeutic approaches for treating pathologies that currently have limited or no effective alternatives. This review aims to provide the reader with the process of translating an idea from the laboratory bench to clinical practice, specifically in the context of TEPs designing for skin wound healing. It encompasses historical perspectives, approved therapies, and offers a distinctive insight into the regulatory framework in Brazil. We explore the essential guidelines for quality testing, and nonclinical proof-of-concept considering the Brazilian Network of Experts in Advanced Therapies (RENETA) and International Standards and Guidelines (ICH e ISO). Adopting a multifaceted approach, our discussion incorporates scientific and industrial perspectives, addressing quality, biosafety, non-clinical viability, clinical trial and real-word data for pharmacovigilance demands. This comprehensive analysis presents a panoramic view of the development of skin TEPs, offering insights into the evolving landscape of this dynamic and promising field.

Outcomes of Biodegradable Temporizing Matrix for Soft Tissue Reconstruction of the Hand and Extremities

Background

NovoSorb biodegradable temporizing matrix (BTM) is a novel, bilayer, synthetic skin substitute made of biodegradable polyurethane foam covered with a sealing membrane. BTM has demonstrated excellent outcomes in burn literature; however, few studies have been published for hand and extremity soft tissue reconstruction.

Methods

All patients who underwent extremity reconstruction with BTM from 2018 to 2023 were reviewed. Demographics, presentations, and clinical outcomes were recorded.

Results

A total of 86 cases from 54 patients (53.7% pediatric; age range: 0-81 years) were included. Common indications included trauma (36%), infection (18.6%), and malignancy (11.6%). BTM was placed over exposed tendon (38.4%), bone (19%), joints (12.8%), nerves (8.1%), and/or blood vessels (7%). BTM served as temporary wound coverage in 26 cases. Complications included hematoma (8.1%), infection (4.7%), and spontaneous delamination (4.7%). Wound closure was successfully obtained without flap use in 93.3%. Poor BTM take was associated with peripheral vascular disease, hypertension, immunosuppression, and BTM hematoma and infection (<0.05).

Conclusion

This study contributes to the growing body of evidence favoring BTM use in challenging reconstructive cases. Although prospective comparative studies are forthcoming, BTM likely has broad applications in reconstructive surgery.

Use of lateral femoral cutaneous nerve blocks by landmark technique is ineffective in decreasing narcotic usage after skin grafts: A retrospective case-control study

INTRODUCTION

Cutaneous burns are commonly treated with autologous skin grafts. Following skin grafting, many patients complain of pain at the donor site. Donor sites are taken most commonly from the lateral thigh, which is innervated by the lateral femoral cutaneous nerve (LFCN). Use of a LFCN blocks should decrease nociception from the donor site.

METHODS

Our group began utilizing LFCN blocks in 2019. Utilizing anatomic landmarks, LFCN blocks were performed on all patients who received autologous skin grafts to reduce perioperative pain. A retrospective cohort study was performed on all patients with 10% or less total body surface areas burns who received an autologous skin graft. A similar cohort from 2016, prior to use of any local or regional analgesia, was used as a historical control. Post-operative enteral and parenteral narcotic analgesics were collected for each post-operative day up to day 5 or discharge (whichever came first) and converted to morphine milligram equivalents (MME) to quantify analgesia after surgery.

RESULTS

Chart review identified 55 patients in the 2020 cohort. Fifty-five patients from the 2016 cohort were matched based upon size of skin graft, total body surface area (TBSA) burned, gender, and age. There were no statistically significant differences between the two groups in terms of size of graft, TBSA burned, age, gender, or type of burn. When examining narcotics usage in the immediate perioperative period (days 0-2), we found no difference between the two groups for total MME (113 vs 133, p = 0.28) or IV MME (38 vs 33, p = 0.45). Similar relationships existed in the extended post-operative period (days 1-5) for total MME (149 vs. 188, t = 0.22) or IV MME (37 vs. 50, t = 0.25). Examining daily narcotic usage also yielded no statistically different values.

CONCLUSION

Our data shows that use of LFCN block by landmark technique did not reduce narcotic usage in patients that undergo skin grafting procedures. Future studies should consider ultrasound-guided LFCN blocks.

Application of pulsed electric field technology to skin engineering

Tissue engineering encompasses a range of techniques that direct the growth of cells into a living tissue construct for regenerative medicine applications, disease models, drug discovery, and safety testing. These techniques have been implemented to alleviate the clinical burdens of impaired healing of skin, bone, and other tissues. Construct development requires the integration of tissue-specific cells and/or an extracellular matrix-mimicking biomaterial for structural support. Production of such constructs is generally expensive and environmentally costly, thus eco-sustainable approaches should be explored. Pulsed electric field (PEF) technology is a nonthermal physical processing method commonly used in food production and biomedical applications. In this review, the key principles of PEF and the application of PEF technology for skin engineering will be discussed, with an emphasis on how PEF can be applied to skin cells to modify their behaviour, and to biomaterials to assist in their isolation or sterilisation, or to modify their physical properties. The findings indicate that the success of PEF in tissue engineering will be reliant on systematic evaluation of key parameters, such as electric field strength, and their impact on different skin cell and biomaterial types. Linking tangible input parameters to biological responses critical to healing will assist with the development of PEF as a sustainable tool for skin repair and other tissue engineering applications.

Current Approaches to Wound Repair in Burns: How far Have we Come From Cover to Close? A Narrative Review

Burn injuries are a significant global health concern, with more than 11 million people requiring medical intervention each year and approximately 180,000 deaths annually. Despite progress in health and social care, burn injuries continue to result in socioeconomic burdens for victims and their families. The management of severe burn injuries involves preventing and treating burn shock and promoting skin repair through a two-step procedure of covering and closing the wound. Currently, split-thickness/full-thickness skin autografts are the gold standard for permanent skin substitution. However, deep burns treated with split-thickness skin autografts may contract, leading to functional and appearance issues. Conversely, defects treated with full-thickness skin autografts often result in more satisfactory function and appearance. The development of tissue-engineered dermal templates has further expanded the scope of wound repair, providing scar reductive and regenerative properties that have extended their use to reconstructive surgical interventions. Although their interactions with the wound microenvironment are not fully understood, these templates have shown potential in local infection control. This narrative review discusses the current state of wound repair in burn injuries, focusing on the progress made from wound cover to wound closure and local infection control. Advancements in technology and therapies hold promise for improving the outcomes for burn injury patients. Understanding the underlying mechanisms of wound repair and tissue regeneration may provide new insights for developing more effective treatments in the future.

Bioengineered Skin for Diabetic Foot Ulcers: A Scoping Review

Diabetic foot ulcers (DFUs) pose a significant threat to individuals with diabetes mellitus (DM), such as lower limb amputation and severe morbidity. Bioengineered skin substitutes (BSS) are alternatives to traditional interventions for treating DFUs, but their efficacy compared to standard wound care (SWC) or other treatment types, such as allografts, remains unknown. A scoping review of human studies was conducted to identify current approaches in the treatment of DFUs using BSS as compared with other treatment options. Systematic searches in PubMed, Cochrane Library, and Web of Science were conducted to identify comparative studies that enrolled 10 or more patients and evaluated wound healing outcomes (closure, time-to-healing, and area reduction). Database searches isolated articles published from 1 December 2012 to 1 December 2022 and were conducted in accordance with PRISMA-ScR guidelines. The literature search yielded 1312 articles, 24 of which were included for the qualitative analysis. Findings in these studies demonstrated that BSS outperformed SWC in all measured outcomes, suggesting that BSS may be a superior treatment for DFUs. Of the 24 articles, 8 articles compared human amniotic membrane allografts (hAMA) to BSS. Conflicting evidence was observed when comparing BSS and hAMA treatments, highlighting the need for future research.

Early history of skin preservation and transplantation; the role of Carl August Ljunggren

During the late 19th and the early 20th century there was an unprecedented development in medical research. Tissue and cell culture rapidly developed into areas with many contributing scientists. The same is true for tissue transplantation. When these achievements are described afterwards in a historical context and a mainline development is constructed, there are researchers whose pioneering work is forgotten. The present paper attempts to correct this and to present a correct description of the start of tissue preservation and transplantation. We have traced relevant original publications in international journals between 1870 and 1920. The traditional view is that Alexis Carrel was the first He received a Nobel Prize 1912 for his work on vascular suture and the transplantation of blood vessels and organs. The same year he published an article on human skin storage and transplantation. This was more than a decade later than Carl August Ljunggren (1860-1934) who 1898 published his pioneering but long forgotten work on human skin preservation and transplantation, and with a vision of tissue banks. Our article contains a brief biography of Ljunggren, and further reconstructs the processes that resulted in the lack of awareness today of his achievements. Conclusion: Carl August Ljunggren was the first to preserve human skin in vitro for prolonged periods, followed by transplantation of the specimens to other patients. He was also the first to propose the use of tissue banks.

Monitoring angiogenesis in skin autografts using photoacoustic microscopy

BACKGROUND

Skin autografts have been broadly used to manage the skin and soft tissue defects. It is important for surgeons to assess the vitality of skin autografts via observing the angiogenesis. However, there is lack of reliable approach for giving the quantitative angiogenesis information on the skin autografts. Recently, photoacoustic microscopy imaging has attracted much attention based on its good performance in angiography.

METHODS

In this study, we aim to monitor angiogenesis in skin autografts via PAM, and further verify its clinical potential for the early prediction of skin autografts clinical outcome.

RESULTS AND CONCLUSIONS

The results indicate that PAM is a feasible, precise, high-resolution, noninvasive technique for the early prediction of necrosis of skin autografts via monitoring the angiogenesis, providing a promising tool for surgeons to use this surgical technology.

Efficacy and Complications Associated with Acellular Dermal Substitute Use in the Treatment of Acute Burns: A Systematic Review and Meta-Analysis

Over several decades, skin substitutes have become an essential tool in acute burn surgery, particularly in major burns, where scarce donor tissues can limit the availability of autografts. This systematic review aimed to assess the efficacy, complication rates, and long-term outcomes of acellular dermal substitutes in acute burns and compare these to conventional skin grafting methods of coverage. A search of PubMed, Web of Science, and CENTRAL for appropriate randomized controlled trials (RCTs), non-randomized trials, and observational studies was conducted. Following screening, nine RCTs and seven observational studies fulfilled our inclusion and exclusion criteria. Our primary outcomes, which were graft take and incidence of infection, found no significant difference between the substitute and control procedures in a meta-analysis (p = 0.37 and p = 0.87, respectively). For our secondary outcomes, the studies were analyzed via narrative synthesis, which reported variable rates of graft loss and duration of acute hospital stay, from which definitive conclusions could not be drawn due to the heterogeneity in reporting. Despite a high risk of bias in the included studies, the evidence reviewed suggests that the treatment of an acute burn with a substitute may improve scar quality when compared to conventional grafting. This review therefore suggests that acellular dermal substitutes offer a viable method for staging the closure of deep partial- and full-thickness acute burns, although more robust RCTs with less heterogeneity are needed to support these conclusions.

Quality management overview for the production of a tissue-engineered human skin substitute in Malaysia

Treatments for skin injuries have recently advanced tremendously. Such treatments include allogeneic and xenogeneic transplants and skin substitutes such as tissue-engineered skin, cultured cells, and stem cells. The aim of this paper is to discuss the general overview of the quality assurance and quality control implemented in the manufacturing of cell and tissue product, with emphasis on our experience in the manufacturing of MyDerm®, an autologous bilayered human skin substitute. Manufacturing MyDerm® requires multiple high-risk open manipulation steps, such as tissue processing, cell culture expansion, and skin construct formation. To ensure the safety and efficacy of this product, the good manufacturing practice (GMP) facility should establish a well-designed quality assurance and quality control (QA/QC) programme. Standard operating procedures (SOP) should be implemented to ensure that the manufacturing process is consistent and performed in a controlled manner. All starting materials, including tissue samples, culture media, reagents, and consumables must be verified and tested to confirm their safety, potency, and sterility. The final products should also undergo a QC testing series to guarantee product safety, efficacy, and overall quality. The aseptic techniques of cleanroom operators and the environmental conditions of the facility are also important, as they directly influence the manufacturing of good-quality products. Hence, personnel training and environmental monitoring are necessary to maintain GMP compliance. Furthermore, risk management implementation is another important aspect of QA/QC, as it is used to identify and determine the risk level and to perform risk assessments when necessary. Moreover, procedures for non-conformance reporting should be established to identify, investigate, and correct deviations that occur during manufacturing. This paper provides insight and an overview of the QA/QC aspect during MyDerm® manufacturing in a GMP-compliant facility in the Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia.

Clinical Indications of Cultured Epithelial Autografts

ABSTRACT

Cultured epithelial autografts (CEAs) have been used for decades as a treatment for massive burn injuries. Cultured epithelial autografts allow for wounds to heal by taking a small sample and growing a patient's own epithelium in culture to create large, graftable sheets. This technique is especially useful in large wounds where donor sites are limited compared with conventional skin grafting. However, CEAs have a variety of uses in wound healing and reconstruction and have the potential to aid in the closure of several types of defects. Cultured epithelial autografts have shown applicability in large burns, chronic nonhealing wounds, ulcerating wounds of various etiologies, congenital defects, wounds requiring specialized epithelium to replace like by like, and wounds in critically ill patients. Several factors must be considered when using CEAs, such as time, cost, and outcomes. In this article, we detail the various clinical applications of CEAs and how they can be situationally advantageous outside of their original purpose.

Using an Elastomeric Skin Protectant to Manage Donor Site Wounds of Split-thickness Skin Grafts: A Case Series

ABSTRACT

Split-thickness skin grafting (STSG) is a common surgical procedure to manage acute and chronic wounds. A plethora of dressings exists to treat STSG donor site wounds (DSWs). Recently, a new elastomeric skin protectant was adopted (Cavilon Advanced Skin Protectant; 3M) in the treatment of incontinence-associated dermatitis. In this report, the authors assess the effects of this elastomeric skin protectant as an alternative wound dressing for STSG donor sites.The authors report a single-center prospective case series that was performed to establish a treatment protocol. Nine consecutive patients with different indications for treatment with an STSG from May to September 2018 were included. Collected data included general patient information, comorbidities, complications, blood loss, pain during dressing change, and the duration of DSW healing.This case series showed promising results in terms of duration of DSW healing when applying the elastomeric skin protectant. The authors also observed less blood loss and less pain during dressing changes. No infections were seen during the trial.

Personalised burn treatment: bedside electrospun nanofibre scaffold with cultured autologous keratinocytes: a case study

Nearly four decades after cultured epidermal autografts (CEA) were first used for the treatment of extensive burn wounds, the current gold standard treatment remains grafting healthy autologous skin from a donor site to the damaged areas, with current skin substitutes limited in their clinical use. We propose a novel treatment approach, using an electrospun polymer nanofibrous matrix (EPNM) applied on-site directly on the CEA-grafted areas. In addition, we propose a personalised treatment on hard-to-heal areas, in which we spray suspended autologous keratinocytes integrated with 3D EPNM applied on-site, directly onto the wound bed. This method enables the coverage of larger wound areas than possible with CEA. We present the case of a 26-year-old male patient with full-thickness burns covering 98% of his total body surface area (TBSA). We were able to show that this treatment approach resulted in good re-epithelialisation, seen as early as seven days post CEA grafting, with complete wound closure within three weeks, and to a lesser extent in areas treated with cell spraying. Moreover, in vitro experiments confirmed the feasibility of using keratinocytes embedded within the EPNM: cell and culture viability, identity, purity and potency were determined. These experiments show that the skin cells are viable and can proliferate within the EPNM. The results presented are of a promising novel strategy for the development of personalised wound treatment, integrating on-the-spot 'printed' EPNM with autologous skin cells, which will be applied at the bedside, over deep dermal wounds, to accelerate healing time and wound closure.

Fractional Epidermal Skin Grafts in Hard-to-Heal Wounds: Case Series

Cellutome^™ is a minimally invasive, automated system for harvesting fractional epidermal micrografts. This therapy is indicated for granulating, small size, poor exuding acute wounds. We enrolled 15 patients with 9 venous leg ulcers and 6 atypical ulcers. The micrografts were applied with a nonadherent dressing and covered with a polyurethane foam and multilayer bandage. We scheduled 3 weekly visits for the change of the secondary dressings and multilayer bandage and clinical assessment (Wound Bed Score [WBS], pain assessment, and healing rate). The lesions were measured with the Silhouette Star^™ system, a software that allows measurement of perimeter and area from a digital image. The only symptom during the procedure was a sensation of warmth. The donor area healed in 2 weeks in all patients (n = 15). We reported an area reduction of 24.30% in typical ulcers and 38.82% in atypical ulcers after 3 weeks. The average WBS improved in all ulcers from 13.06 to 14.93. The average healing rate was 0.19 mm/day both in typical and atypical ulcers. Consequently, in our small case series fractionated epidermal graft treatment significantly promoted the healing rate in all chronic ulcers regardless of etiology. Future studies with larger case series will be needed.

Preparation of laser microporous porcine acellular dermal matrix and observation of wound transplantation

To prepare a new type of porcine acellular dermis matrix (PADM) with the new laser microporous technique and verify its safety and feasibility. A novel porcine acellular dermis matrix (ADM) was prepared by using sequential combined decellularization of trypsin, neutral protease and SDS solution method and fully rinsed with ultrasonic wave. Specific laser microporous technology was used to prepare the laser micropore porcine acellular dermal matrix (LPADM). SD rats were chose as the animal models and autologous skin was transplanted by one-step method to observe and detect the graft activity, immunogenicity and vascularization degree of the novel PADM. A porcelain white, shiny, soft and elastic dermal matrix was prepared in this study, the results showed low DNA residue and low cytotoxicity. HE staining and SEM observation revealed that the PADM had neither residual cells nor cell fragments, while the collagen bundles were intact and orderly arranged. All the SD rats survived. No infection or skin allergy was found after surgery. None of the animals lost weight. Histological examination showed that the LPADM was fully vascularized with little tissue destruction in the experiment group. Immunohistochemical staining for CD31 showed ideal vascularization in the experiment group, and immunohistochemical staining for TNF-α showed there were no statistical significance of inflammatory reaction in both groups. This study demonstrated that the novel PADM prepared by sequential combined decellularization of trypsin, neutral protease and SDS solution method and new laser microporous technique was effective and safe in animal transplantation.

Getting Into One's Skin: The History of Skin Autografting

Surgeons who treat and manage complex wounds rely on many techniques and modalities to properly close their wounds. In modern times, the concept of the reconstructive ladder helps practitioners make decisions on which method to employ to create the best result. Skin autografting is a part of that algorithm, but few know of the arduous history of this field. Dating back thousands of years ago, the history of skin autografting is complex and spans several continents and eras. This article discusses the history and nuance of a surgical technique that has had years of refinement. The discussion begins with ancient times and delves into how skin autografting made a resurgence during the renaissance and the late 1800s and the influence that World War I posed on the advancement of this surgical principle.

From ancient Egypt to the dermatologic office: An overview of skin substitutes and modern-day applications in dermatologic surgery

Skin grafting (specifically xenografting) dates back to as early as 1500 before Christ (BC) in the Ebers papyrus, an Egyptian medical papyrus. In 1503, the use of human skin allograft was described in the manuscript of Branca of Sicily, and among the Hindu Tilemaker Caste approximately 2500-3000 years ago, surgeons repaired defects secondary to nose amputations of those who committed adultery and thievery. Over the years, many advancements in skin grafts/substitutes and their applications have propelled the field to focus on better graft survival, contracture prevention, cosmesis, and quality of life. We provide a general overview of skin substitutes (SS) with a particular focus on placental SS and their current applications in dermatologic surgery.

Application of Modified Triangular Perforator Flap in Repair of Small and Medium-Sized Facial Defect

Background

We investigated the application of local perforator flap or island flap with a modified triangular to repair small and medium facial defects.

Methods

(1) Before the operation, a Doppler flowmeter was used to investigate the superficial exit point of the perforator artery. The length to breadth ratio of the flap was more than 3-4 times, and it contained 1-2 perforator vessels. (2) The lesion was excised, and the skin was cut along the design line of the flap. The flap was separated and trimmed based on the defect degree. (3) The blood supply was confirmed, and the defect was then covered with the flap by "rotation and advancement" approach without causing tension. The incision was finally sutured in layers. (4) Postoperative routine care was performed according to the situation.

Results

The functional morphology and appearance of all 23 cases of skin flaps successfully recovered during follow-up. There was no major aesthetic and malformation recorded.

Conclusion

In summary, the modified triangular perforator flap can improve the functional appearance at the repaired small and medium facial defects.

Classic and Current Opinions in Human Organ and Tissue Transplantation

Graft tolerance is a pathophysiological condition heavily reliant on the dynamic interaction of the innate and adaptive immune systems. Genetic polymorphism determines immune responses to tissue/organ transplantation, and intricate humoral and cell-mediated mechanisms control these responses. In transplantation, the clinician's goal is to achieve a delicate equilibrium between the allogeneic immune response, undesired effects of the immunosuppressive drugs, and the existing morbidities that are potentially life-threatening. Transplant immunopathology involves sensitization, effector, and apoptosis phases which recruit and engages immunological cells like natural killer cells, lymphocytes, neutrophils, and monocytes. Similarly, these cells are involved in the transfer of normal or genetically engineered T cells. Advances in tissue transplantation would involve a profound knowledge of the molecular mechanisms that underpin the respective immunopathology involved and the design of precision medicines that are safe and effective.

New Closed-Form Solution for Quadratic Damped and Forced Nonlinear Oscillator with Position-Dependent Mass: Application in Grafted Skin Modeling

The paper deals with modelling and analytical solving of a strong nonlinear oscillator with position-dependent mass. The oscillator contains a nonlinear restoring force, a quadratic damping force and a constant force which excites vibration. The model of the oscillator is a non-homogenous nonlinear second order differential equation with a position-dependent parameter. In the paper, the closed-form exact solution for periodic motion of the oscillator is derived. The solution has the form of the cosine Ateb function with amplitude and frequency which depend on the coefficient of mass variation, damping parameter, coefficient of nonlinear stiffness and excitation value. The proposed solution is tested successfully via its application for oscillators with quadratic nonlinearity. Based on the exact closed-form solution, the approximate procedure for solving an oscillator with slow-time variable stiffness and additional weak nonlinearity is developed. The proposed method is named the ‘approximate time variable Ateb function solving method’ and is applicable to many nonlinear problems in physical and applied sciences where parameters are time variable. The method represents the extended and adopted version of the time variable amplitude and phase method, which is rearranged for Ateb functions. The newly developed method is utilized for vibration analysis of grafted skin on the human body. It is found that the grafted skin vibration properties, i.e., amplitude, frequency and phase, vary in time and depend on the dimension, density and nonlinear viscoelastic properties of the skin and also on the force which acts on it. The results obtained analytically are compared with numerically and experimentally obtained ones and show good agreement.

Objective Skin Quality Assessment after Reconstructive Procedures for Facial Skin Defects

Local random skin flaps and skin grafts are everyday surgical techniques used to reconstruct skin defects. Although their clinical advantages and disadvantages are well known, there are still uncertainties with respect to their long-term results. Hence, the aim of this study was to evaluate outcomes more than one-year post operatively using objective measurement devices. The study included 31 facial defects reconstructed with local random flap, 30 facial defects reconstructed with split-thickness skin grafts (STSGs) and 30 facial defects reconstructed with full-thickness skin grafts (FTSGs). Skin quality was objectively evaluated using MP6 noninvasive probes (Courage + Khazaka GmbH, Cologne, Germany), which measure melanin count, erythema, hydration, sebum, friction and transepidermal water loss. The results showed that there were no significant differences in melanin count, erythema, hydration, sebum level, friction value and transepidermal water loss (TEWL) between the site reconstructed with random local flaps and the same site on the healthy contralateral side of the face. However, both FTSGs and STSGs showed significantly higher levels in terms of TEWL and erythema, whereas the levels of hydration, sebum and friction were significantly lower compared to the healthy contralateral side. Moreover, STSGs resulted in a significant difference in melanin count. These findings imply that the complex pathophysiology of the wound-healing process possibly results in better skin-quality outcomes for random local flaps than skin autografts. Consequently, this suggests that random local flaps should be implemented whenever possible for the reconstruction of facial region defects.

Skin regeneration, repair, and reconstruction: present and future

Background

Large skin defects caused by trauma (e.g., burns) or due to other reasons (e.g., tumor-related skin resections) require sufficient skin replacement. The constant improvement of innovative methods of skin replacement and skin expansion mean that even burn victims with more than 80% body surface burned have a realistic chance of survival. Due to these new developments, not only has survival rate increased, but also quality of life has increased tremendously over the past decades.

Methods

The aim of this review is to present an overview of current standards and future trends concerning the treatment of skin defects. The main focus is placed on the most important technologies and future trends.

Results

Autologous skin grafting was developed more than 3500 years ago. Several approaches and techniques have been discovered and established in burn care and plastic surgery since then. Great achievements were made during the 19th and 20th centuries. Many of these old and new techniques are still part of modern burn and plastic surgery. Today, autologous skin grafting is still considered to be the gold standard for many wounds, but new technologies have been developed, ranging from biological to synthetic skin replacement materials.

Conclusion

Today, old and new technologies are available which allow us new treatment concepts. All this has led to the reconstructive clockwork for reconstructive surgery of the 21st century.

Surgical Treatment of Vitiligo

Vitiligo is described as a dermatological condition characterized by pigmentation disorders in both the skin and mucous membranes. Clinically, this disease is characterized by the presence of well-defined white areas of various shapes and sizes, which are a manifestation of a reduced number of melanocytes. Due to the fact that vitiligo can be a significant cosmetic problem for patients, a number of methods are currently available to help fight for a better skin appearance. If all the available non-invasive procedures turn out to be ineffective, surgery can help, which is a very good alternative in the case of difficult-to-treat but stable changes. Both the development of new techniques and modifications to the already available treatment of cell and tissue transplantation give hope to numerous patients around the world. The effectiveness of a particular method is determined by its appropriate selection depending on the lesions undergoing therapy. Each form of surgical intervention has its advantages and disadvantages, which, along with the location or size of the treated hypopigmentation area, should be analyzed by a doctor and discussed with their patient. This article is an overview of the currently available methods of surgical treatment of vitiligo and a comparison of their pros and cons.