Multidisciplinary long-term care and modern surgical treatment of congenital melanocytic nevi - recommendations by the CMN surgery network.

In recent years, our knowledge of congenital melanocytic nevi (CMN) has greatly expanded. This has led to a paradigm shift. The present article represents a commentary by an interdisciplinary group of physicians from German-speaking countries with extensive experience in long-term care and surgical treatment of children and adults with CMN (CMN surgery network, "Netzwerk Nävuschirurgie", NNC). The authors address aspects such as the indication for treatment as well as treatment planning and implementation under these new premises. Adequate counseling of parents on conservative and/or surgical management requires an interdisciplinary exchange among physicians and individualized planning of the intervention, which frequently involves a multi-stage procedure. Today, the long-term aesthetic outcome is at the center of any therapeutic endeavor, whereas melanoma prevention plays only a minor role. The premise of "removal at any cost" no longer holds. Potential treatment-related adverse effects (hospitalization, wound healing disorders, and others) must be carefully weighed against the prospects of a beneficial outcome. In this context, the use of dermabrasion in particular must be critically evaluated. At a meeting of the NNC in September 2018, its members agreed on a consensus-based position on dermabrasion, stating that the procedure frequently leads to impaired wound healing and cosmetically unfavorable or hypertrophic scarring. Moreover, dermabrasion is considered to be commonly associated with considerable repigmentation that usually occurs a number of years after the procedure. In addition, the NNC members saw no benefit in terms of melanoma prevention. In the future, physicians should therefore thoroughly caution about the potential risks and often limited cosmetic benefits of dermabrasion.

Insight into the redox status of inflammatory skin equivalents as determined by EPR spectroscopy.

Atopic dermatitis (AD) is a chronic inflammatory skin disease whose pathogenesis is still not fully understood. Since inflammatory processes correlate with oxidative stress, the redox status may play a key role in AD. In this study, electron paramagnetic resonance (EPR) spectroscopy was mainly used to investigate the redox status in normal and inflammatory skin equivalents mimicking characteristics of AD in vitro using EPR spin probes (TEMPO, PCA) and a spin trap (DMPO). The total antioxidant status in the hydrophilic and lipophilic compartments of skin (microenvironment) showed no differences between the skin equivalents. In the inflammatory skin equivalents, a decreased glutathione concentration in the epidermis and an increased metabolic radical production could be observed compared to normal skin equivalents. The induction of external stress by simulated solar irradiation (UVB-NIR) resulted in the same amount and type of radicals in normal and inflammatory skin equivalents. For the first time, the antioxidant and oxidant status of inflammatory in vitro skin equivalents was analyzed by EPR to elucidate their redox status using different methods which focus on various microenvironments. Our investigations suggested that the redox status in atopic skin could be different, but this should be investigated more comprehensively, because the results can vary depending on the used methods and where the investigations take place.

A Cultured Autologous Dermo-epidermal Skin Substitute for Full-Thickness Skin Defects: A Phase I, Open, Prospective Clinical Trial in Children.

BACKGROUND: The management of deep partial-thickness and full-thickness skin defects remains a significant challenge. Particularly with massive defects, the current standard treatment, split-thickness skin grafting, is fraught with donor-site limitations and unsatisfactory long-term outcomes. A novel, autologous, bioengineered skin substitute was developed to address this problem. METHODS: To determine whether this skin substitute could safely provide permanent defect coverage, a phase I clinical trial was performed at the University Children's Hospital Zurich. Ten pediatric patients with acute or elective deep partial- or full-thickness skin defects were included. Skin grafts of 49 cm were bioengineered using autologous keratinocytes and fibroblasts isolated from a patient's small skin biopsy specimen (4 cm), incorporated in a collagen hydrogel. RESULTS: Graft take, epithelialization, infection, adverse events, skin quality, and histology were analyzed. Median graft take at 21 days postoperatively was 78 percent (range, 0 to 100 percent). Healed skin substitutes were stable and skin quality was nearly normal. There were four cases of hematoma leading to partial graft loss. Histology at 3 months revealed a well-stratified epidermis and a dermal compartment comparable to native skin. Mean follow-up duration was 15 months. CONCLUSIONS: In the first clinical application of this novel skin substitute, safe coverage of skin defects was achieved. Safety and efficacy phase II trials comparing the novel skin substitute to split-thickness skin grafts are ongoing. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

The Effect of Wound Dressings on a Bio-Engineered Human Dermo-Epidermal Skin Substitute in a Rat Model.

Autologous bio-engineered dermo-epidermal skin substitutes are a promising treatment for large skin defects such as burns. For their successful clinical application, the graft dressing must protect and support the keratinocyte layer and, in many cases, possess antimicrobial properties. However, silver in many antimicrobial dressings may inhibit keratinocyte growth and differentiation. The purpose of our study was to evaluate the effect of various wound dressings on the healing of a human hydrogel-based dermo-epidermal skin substitute in preparation for the first-in-human clinical trials. Human dermo-epidermal skin substitutes approved for clinical trials were produced under good manufacturing practice conditions, transplanted onto immuno-incompetent rats, and dressed with either Vaseline Gauze™ (Kendall Medtronic, Minneapolis, USA), Suprathel (PolyMedics Innovations GmbH, Denkendorf, Germany), Urgotul SSD (Urgo Medical, Shepshed, United Kingdom), Mepilex AG (Mölnlycke Health Care, Gothenburg, Sweden), or Acticoat™ (Smith&Nephew, Baar, Switzerland). Grafts were assessed clinically for take, epithelialization, and infection at 10 and 21 days post-transplantation, and histologically at 21 days. There were three subjects each in the Vaseline Gauze™ and Suprathel groups, and four subjects each in the Urgotul SSD, Mepilex AG, and Acticoat™ groups. For all samples, the take rate was 100% and the expected keratinocyte number, epithelialization and epidermal stratification were observed. All of the dressings in the current study were well tolerated by our human dermo-epidermal skin substitute. The tolerance of the silver-based dressings is particularly relevant given the high risk of bacterial contamination with large skin defects, and provides pivotal information as we embark on clinical trials for this novel skin substitute.