Thermal Imaging for Burn Wound Depth Assessment: A Mixed-Methods Implementation Study

Background: Implementing innovations emerging from clinical research can be challenging. Thermal imagers provide an accessible diagnostic tool to increase the accuracy of burn wound depth assessment. This mixed-methods implementation study aimed to assess the barriers and facilitators, design implementation strategies, and guide the implementation process of thermal imaging in the outpatient clinic of a burn centre. Methods: This study was conducted between September 2022 and February 2023 in Beverwijk, The Netherlands. Semi-structured interviews with burn physicians guided by the Consolidated Framework for Implementation Research (CFIR) were conducted to identify barriers and facilitators. Based on the barriers, implementation strategies were developed with the CFIR-ERIC Matching Tool, and disseminated to support the uptake of the thermal imager. Subsequently, thermal imaging was implemented in daily practice, and an iterative RE-AIM approach was used to evaluate the implementation process. Results: Common facilitators for the implementation of the thermal imager were the low complexity, the relative advantage above other diagnostic tools, and benefits for patients. Common barriers were physicians' attitude towards and perceived value of the intervention, the low compatibility with the current workflow, and a lack of knowledge about existing evidence. Six implementation strategies were developed: creating a formal implementation blueprint, promoting adaptability, developing educational materials, facilitation, conducting ongoing training, and identifying early adopters. These strategies resulted in the effective implementation of the thermal imager, reflected by a >70% reach among eligible patients, and >80% effectiveness and adoption. Throughout the implementation process, compatibility, and available resources remained barriers, resulting in low ratings on RE-AIM dimensions. Conclusions: This study developed implementation strategies based on the identified CFIR constructs that impacted the implementation of a thermal imager for burn wound assessment in our outpatient clinic. The experiences and findings of this study could be leveraged to guide the implementation of thermal imaging and other innovations in burn care.

IDENTIFICATION OF POTENTIALLY MODIFIABLE FACTORS TO IMPROVE RECOGNITION AND OUTCOME OF NECROTIZING SOFT-TISSUE INFECTIONS

ABSTRACT

Background : Necrotizing soft-tissue infections (NSTIs) present a surgical emergency of increasing incidence, which is often misdiagnosed and associated with substantial mortality and morbidity. A retrospective multicenter (11 hospitals) cohort study was initiated to identify the early predictors of misdiagnosis, mortality, and morbidity (skin defect size and amputation). Methods : Patients of all ages who presented with symptoms and were admitted for acute treatment of NSTIs between January 2013 and December 2017 were included. Generalized estimating equation analysis was used to identify early predictors (available before or during the first debridement surgery), with a significance level of P < 0.05. Results : The median age of the cohort (N = 216) was 59.5 (interquartile range = 23.6) years, of which 138 patients (63.9%) were male. Necrotizing soft-tissue infections most frequently originated in the legs (31.0%) and anogenital area (30.5%). More than half of the patients (n = 114, 54.3%) were initially misdiagnosed. Thirty-day mortality was 22.9%. Amputation of an extremity was performed in 26 patients (12.5%). Misdiagnosis was more likely in patients with a higher Charlson Comorbidity Index (β = 0.20, P = 0.001), and less likely when symptoms started in the anogenital area (β = -1.20, P = 0.003). Besides the established risk factors for mortality (septic shock and age), misdiagnosis was identified as an independent predictor of 30-day mortality (β = 1.03, P = 0.01). The strongest predictors of the final skin defect size were septic shock (β = 2.88, P < 0.001) and a skin-sparing approach to debridement (β = -1.79, P = 0.002). Conclusion : Recognition of the disease is essential for the survival of patients affected by NSTI, as is adequate treatment of septic shock. The application of a skin-sparing approach to surgical debridement may decrease morbidity.

Timing of surgery in acute deep partial-thickness burns: A study protocol

For deep partial-thickness burns no consensus on the optimal treatment has been reached due to conflicting study outcomes with low quality evidence. Treatment options in high- and middle-income countries include conservative treatment with delayed excision and grafting if needed; and early excision and grafting. The majority of timing of surgery studies focus on survival rather than on quality of life. This study protocol describes a study that aims to compare long-term scar quality, clinical outcomes, and patient-reported outcomes between the treatment options. A multicentre prospective study will be conducted in the three Dutch burn centres (Rotterdam, Beverwijk, and Groningen). All adult patients with acute deep-partial thickness burns, based on healing potential with Laser Doppler Imaging, are eligible for inclusion. During a nine-month baseline period, standard practice will be monitored. This includes conservative treatment with dressings and topical agents, and excision and grafting of residual defects if needed 14-21 days post-burn. The subsequent nine months, early surgery is advocated, involving excision and grafting in the first week to ten days post-burn. The primary outcome compared between the two groups is long-term scar quality assessed by the Patient and Observer Scar Assessment Scale 3.0 twelve months after discharge. Secondary outcomes include clinical outcomes and patient-reported outcomes like quality of life and return to work. The aim of the study is to assess long-term scar quality in deep partial-thickness burns after conservative treatment with delayed excision and grafting if needed, compared to early excision and grafting. Adding to the ongoing debate on the optimal treatment of these burns. The broad range of studied outcomes will be used for the development of a decision aid for deep partial-thickness burns, to fully inform patients at the point of consent to surgery and support optimal person-centred care.

The efficacy of therapeutic interventions on paediatric burn patients' height, weight, body composition, and muscle strength: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of therapeutic interventions on pediatric burn patients' height, weight, body composition, and muscle strength.

METHODS

A systematic literature search was conducted in PubMed, Embase, and Web of Science up to March 2021. Eligible interventional studies reported metrics on the height, weight, body composition, or muscle strength of pediatric burn patients in a peer-reviewed journal. Meta-analyses were performed if ≥ 2 trials of clinical homogeneity reported on an outcome measure at the same time point post-burn.

RESULTS

Twenty-six interventional studies were identified, including twenty-two randomised controlled trials and four non-randomised trials. Most studies were conducted by a single institution. On average, the burn covered 45.3% ( ± 9.9) of the total body surface area. Three categories of interventions could be distinguished: rehabilitative exercise programs, pharmacologic agents, and nutrition support.

CONCLUSIONS

Each of the interventions had a positive effect on height, weight, body composition, or muscle strength. The decision to initiate an intervention should be made on a case-by-case basis following careful consideration of the benefits and risks. In future research, it is important to evaluate the heterogeneity of intervention effects and whether participation in an intervention allowed pediatric burn patients to reach the physical and functional status of healthy peers.

An in silico modeling approach to understanding the dynamics of the post-burn immune response

Introduction

Burns are characterized by a massive and prolonged acute inflammation, which persists for up to months after the initial trauma. Due to the complexity of the inflammatory process, Predicting the dynamics of wound healing process can be challenging for burn injuries. The aim of this study was to develop simulation models for the post-burn immune response based on (pre)clinical data.

Methods

The simulation domain was separated into blood and tissue compartments. Each of these compartments contained solutes and cell agents. Solutes comprise pro-inflammatory cytokines, anti-inflammatory cytokines and inflammation triggering factors. The solutes diffuse around the domain based on their concentration profiles. The cells include mast cells, neutrophils, and macrophages, and were modeled as independent agents. The cells are motile and exhibit chemotaxis based on concentrations gradients of the solutes. In addition, the cells secrete various solutes that in turn alter the dynamics and responses of the burn wound system.

Results

We developed an Glazier-Graner-Hogeweg method-based model (GGH) to capture the complexities associated with the dynamics of inflammation after burn injuries, including changes in cell counts and cytokine levels. Through simulations from day 0 - 4 post-burn, we successfully identified key factors influencing the acute inflammatory response, i.e., the initial number of endothelial cells, the chemotaxis threshold, and the level of chemoattractants.

Conclusion

Our findings highlight the pivotal role of the initial endothelial cell count as a key parameter for intensity of inflammation and progression of acute inflammation, 0 - 4 days post-burn.

Improving patient care by virtual case discussion between plastic surgeons and residents of Uganda and the Netherlands

INTRODUCTION

Traditional on-site missions of plastic surgeons from "high-income countries" in "low- and middle-income countries" are often limited in time and lack proper follow-up. Regular digital collaboration could lead to a more impactful and durable exchange of knowledge for plastic surgeons and residents in both settings.

AIMS

The aim of this study was to evaluate the satisfaction of the first twelve months of weekly digital meetings, explore advantages/disadvantages, and to provide tools for similar initiatives.

METHODS

Weekly meetings started from August 2021. An encrypted digital connection allowed residents and plastic surgeons from Uganda and the Netherlands to discuss cases for educational purposes, where treatment options were considered. After twelve months, a survey was sent to participants from both countries to indicate the meetings' strengths, weaknesses, and possible improvements.

RESULTS

A total of 18 participants responded to the questionnaire (ten plastic surgeons, six residents, and two researchers). The strengths of the meetings were the accessibility of the meetings, knowledge exchange and practice for residents' final exams. Possible improvements included having a clear format for patient discussion, a session moderator and better internet connectivity. Moreover, a database to assess the impact of the given intervention on the patient cases by evaluating postoperatively (e.g. three months), could further improve clinical care.

CONCLUSIONS

Virtual patient discussions subjectively contributed to medical education at both locations. Improved digital infrastructure and a collaborative database could further maximize learning capacity. Furthermore, digital proctoring is a promising way to establish sustainable collaborations between high- and low-resource countries.

Intralesional corticosteroid administration in the treatment of keloids: a survey among Dutch dermatologists and plastic surgeons

BACKGROUND

Intralesional corticosteroid administration (ICA) is a first-line therapy in keloid treatment. However, its clinical results are still highly variable and often suboptimal. Treatment results may strongly be influenced by various ways of ICA.

OBJECTIVE

To explore the prevailing practice of ICA in keloid treatment among dermatologists and plastic surgeons in the Netherlands.

METHODS

The survey was constructed based on a scoping review on ICA in keloid treatment. Members of the Dutch Society for Plastic surgery and the Dutch Society for Dermatology and Venereology were asked to participate.

RESULTS

One hundred and thirty-six responses were obtained. One hundred and thirty (95.6%) participants used triamcinolone acetonide. The majority (54.7%) did not use local anesthesia for pain reduction. Reported corticosteroid dosing that one would inject in one specific keloid differed by a factor of 40. Treatment intervals varied from 1 week to more than 8 weeks. The keloid center was most often injected (46.9%), followed by subepidermal (18.0%).

CONCLUSIONS

A wide variety in ICA for keloids is noted among dermatologists and plastic surgeons, even in a limited geographic region and when evidence points toward an optimal way of treatment. Future studies and better implementation of existing evidence may reduce variation in ICA and optimize its treatment results.

The Role of Burn Centers in the Treatment of Necrotizing Soft-Tissue Infections: A Nationwide Dutch Study

Patients with extensive and complex wounds due to Necrotizing Soft-Tissue Infections (NSTI) may be referred to a burn center. This study describes the characteristics, outcomes, as well as diagnostic challenges of these patients. Patients admitted to three hospitals with a burn center for the treatment of NSTI in a 5-year period were included. Eighty patients (median age 54 years, 60% male) were identified, of whom 30 (38%) were referred by other centers, usually after survival of the initial septic phase. Those referred from other centers, compared to those primarily admitted to the study hospitals, were more likely to have group A streptococcal involvement (62% vs 35%, p = .02), larger wounds (median 7% vs 2% total body surface area, p < .001), and a longer length of stay (median 49 vs 22 days, p < .001). Despite a high incidence of septic shock (50%), the mortality rate was low (12%) for those primarily admitted. Approximately half (53%) of the patients were initially misdiagnosed upon presentation, which was associated with delay to first surgery (16 hours vs 4 hours, p < .001). Those initially misdiagnosed had more (severe) comorbidities, and less frequently reported pain or blue livid discoloration of the skin. This study underlines the burn centers' function as referral centers for extensively affected patients with NSTI. Besides the unique wound and reconstructive expertise, the low mortality rate indicates these centers provide adequate acute care as well. A major remaining challenge remains recognition of the disease upon presentation. Future studies in which factors associated with misdiagnosis are explored are needed.

Short- and Long-term Outcomes of an Acellular Dermal Substitute versus Standard of Care in Burns and Reconstructions: A Phase I/II Intrapatient Randomized Controlled Trial

OBJECTIVE

Dermal substitutes promote dermal regeneration and improve scar quality, but knowledge gaps remain regarding their efficacy and indications for use. The authors investigated the safety and short- and long-term efficacy of an acellular dermal substitute in patients with full-thickness wounds.

METHODS

This intrapatient randomized controlled, open-label, phase I (safety) and phase II (efficacy) study compared treatment with Novomaix (Matricel GmbH), a dermal collagen/elastin-based scaffold, with split-thickness skin graft (STSG) only. The primary safety outcome was graft take at 5 to 7 days postsurgery. Postsurgical scar quality was assessed by measuring elasticity, color, and scores on the Patient and Observer Scar Assessment Scale at 3 months, 12 months, and 6 years.

RESULTS

Twenty-five patients were included, of which 24 received treatment allocation. Graft take and wound healing were statistically significantly lower/delayed in the dermal matrix group compared with STSG alone (P < .004). Serious adverse events were delayed epithelialization in four dermal matrix and three STSG study areas. At 12 months postsurgery, skin extension (P = .034) and elasticity (P = .036) were better for the dermal matrix group compared with the group receiving STSG alone. Other scar quality parameters at 12 months and 6 years did not differ between treatment arms.

CONCLUSIONS

The dermal substitute was a safe treatment modality for full-thickness wounds. Compared with STSG alone, time to wound healing was slightly increased. Nevertheless, scar quality at 12 months seemed somewhat improved in the wounds treated with the dermal substitute, indicative of enhanced scar maturation. In the long term, final scar quality was similar for both treatment modalities.

The Effect of Burns on Children's Growth Trajectory: A Nationwide Cohort Study

This study evaluates the short- and long-term effect of burns on children's height and weight, by comparing their pre and postburn growth trajectory. We invited children (≤17 years old), who sustained a burn requiring surgical treatment or admission at one of the Dutch burn centers in 2013 (n = 175). As well as children who sustained a severe burn, covering >10% of the total body surface area (TBSA), throughout 2009-2018 (n = 228). Data was collected from a survey on health-related topics, Youth Health Care records, and the Dutch Burn Repository R3. For all participants, height and weight were converted to Z-scores using Dutch reference values. Linear mixed modeling, nested on the individual level, was used to examine the associations between burns and children's height and weight Z-scores. Children's height and weight Z-scores remained within the normal range throughout the study period. During the first-year postburn, children's height and weight Z-scores decreased by -0.21 (95% CI -0.41, -0.01) and -0.23 (95% CI -0.46, -0.04), respectively. Beyond the first-year postburn, estimates were consistent with a positive linear association between burn size and the overall effect of burns on participants' height and weight Z-scores. This included a modest, but statistically significant, effect among participants with a burn covering ≤4.5% and >14.0% of the TBSA. Sensitivity analyses did not alter our findings. In conclusion, children were on track or even surpassed their growth potential. Our findings could therefore be considered reassuring to patients, parents, and clinicians.

Current Practice in Keloid Treatment: a Survey of Dutch Dermatologists and Plastic Surgeons

BACKGROUND

Several therapeutic options are available for the treatment of keloids, but it remains unclear which treatment options are most commonly used by practitioners.

OBJECTIVE

To explore the prevailing treatment for different keloid phenotypes among dermatologists and plastic surgeons in the Netherlands.

METHODS

Members of the Dutch society for Plastic surgery and the Dutch society for Dermatology and Venereology were asked to participate. Questions elaborated on the treatment for a small and a large keloid on the mandibula and multiple keloids on the chest.

RESULTS

One hundred forty-three responses were obtained. Heterogeneity in treatment was extremely high for the small, large, and multiple keloids with 27, 35, and 33 various first choices, respectively. Intralesional corticosteroids were most often chosen for all 3 different keloid phenotypes. These were mostly (61%) administered as monotherapy for the small keloid and mostly combined with other treatments for the large keloid (19%) and multiple keloids (43%). Surgery was chosen regularly (22%) for the large keloid, mostly combined with intralesional corticosteroids (10%) or brachytherapy (8.4%).

CONCLUSION

Keloid treatment is very heterogeneous among dermatologists and plastic surgeons, even in a relatively small country as the Netherlands. Moreover, the treatment choice depends on the keloid phenotype.

Children's growth and motor development following a severe burn: a systematic review

Background

The epidemiological data on post-burn growth, body composition and motor development is ambiguous and scattered. The aim of this systematic review was therefore to summarize the current body of evidence on post-burn growth, body composition and motor development in children.

Methods

A literature search was conducted in PubMed, EMBASE and Web of Science up to March 2021. We considered observational studies that reported (1) metrics on weight, height, body composition, bone mineral content, bone mineral density or motor development, in (2) paediatric burn patients and (3) published in a peer-reviewed journal.

Results

A total of 16 studies were included. Each of the included studies used quantitative methods, but with differing methodology: prospective cohort studies (n = 8), retrospective chart reviews (n = 3), case-control studies (n = 2), cross sectional studies (n = 2) and a retrospective cohort study (n = 1). When combined, the included studies represented 2022 paediatric burn patients, with a mean age of 7.7 (±3.2) years. The average burn size was 52.8% (±12.7) of the total body surface area. Identified outcome measures included weight (n = 12), height (n = 7), muscular strength (n = 4), bone mineral content (n = 5), bone mineral density (n = 5), body mass index (n = 3), fat mass (n = 5), lean body mass (n = 7) and fine and gross motor development (n = 1).

Conclusions

Following an initial decline, patients' growth and motor development started to recover during the first or second year post-burn. Nonetheless, burns may have a profound and prolonged effect on the paediatric burn patients' muscular strength, bone mineral content and lean body mass. It should be noted that the vast majority of studies included only patients with burns covering ≥30% total body surface area. The evidence presented in this review may thus not be representative of the whole paediatric burn population.

Stromal vascular fraction-enriched fat grafting as treatment of adherent scars: study design of a non-randomized early phase trial

Background

In the last decades, autologous fat grafting has been used to treat adherent dermal scars. The observed regenerative and scar-reducing properties have been mainly ascribed to the tissue-derived stromal vascular fraction (tSVF) in adipose tissue. Adipose tissue’s components augment local angiogenesis and mitosis in resident tissue cells. Moreover, it promotes collagen remodeling. We hypothesize that tSVF potentiates fat grafting-based treatment of adherent scars. Therefore, this study aims to investigate the effect of tSVF-enriched fat grafting on scar pliability over a 12-month period.

Methods and design

A clinical multicenter non-randomized early phase trial will be conducted in two dedicated Dutch Burn Centers (Red Cross Hospital, Beverwijk, and Martini Hospital, Groningen). After informed consent, 46 patients (≥18 years) with adherent scars caused by burns, necrotic fasciitis, or degloving injury who have an indication for fat grafting will receive a sub-cicatricic tSVF-enriched fat graft. The primary outcome is the change in scar pliability measured by the Cutometer between pre- and 12 months post-grafting. Secondary outcomes are scar pliability (after 3 months), scar erythema, and melanin measured by the DSM II Colormeter; scar quality assessed by the patient and observer scales of the Patient and Observer Scar Assessment Scale (POSAS) 2.0; and histological analysis of scar biopsies (voluntary) and tSVF quality and composition. This study has been approved by the Dutch Central Committee for Clinical Research (CCMO), NL72094.000.20.

Conclusion

This study will test the clinical efficacy of tSVF-enriched fat grafting to treat dermal scars while the underlying working mechanism will be probed into too.

Trial registration

Dutch Trial Register NL 8461. Registered on 16 March 2020

Hydrosurgical and conventional debridement of burns: randomized clinical trial

BACKGROUND

Tangential excision of burned tissue followed by skin grafting is the cornerstone of burn surgery. Hydrosurgery has become popular for tangential excision, with the hypothesis that enhanced preservation of vital dermal tissue reduces scarring. The aim of this trial was to compare scar quality after hydrosurgical versus conventional debridement before split-skin grafting.

METHODS

A double-blind randomized within-patient multicentre controlled trial was conducted in patients with burns that required split-skin grafting. One wound area was randomized to hydrosurgical debridement and the other to Weck knife debridement. The primary outcome was scar quality at 12 months, assessed with the observer part of the Patient and Observer Scar Assessment Scale (POSAS). Secondary outcomes included complications, scar quality, colour, pliability, and histological dermal preservation.

RESULTS

Some 137 patients were randomized. At 12 months, scars of the hydrosurgical debrided wounds had a lower POSAS observer total item score (mean 2.42 (95 per cent c.i. 2.26 to 2.59) versus 2.54 (95 per cent c.i. 2.36 to 2.72; P = 0.023)) and overall opinion score (mean 3.08 (95 per cent c.i. 2.88 to 3.28) versus 3.30 (95 per cent c.i. 3.09-3.51); P = 0.006). Patient-reported scar quality and pliability measurements were significantly better for the hydrosurgically debrided wounds. Complication rates did not differ between both treatments. Histologically, significantly more dermis was preserved with hydrosurgery (P < 0.001).

CONCLUSION

One year after surgery scar quality and pliability was better for hydrosurgically debrided burns, probably owing to enhanced histological preservation of dermis.

REGISTRATION NUMBER

Trial NL6085 (NTR6232 (http://www.trialregister.nl)).

The future of burn care from a complexity science perspective

Healthcare is undergoing a profound technological and digital transformation and has become increasingly complex. It is important for burns professionals and researchers to adapt to these developments which may require new ways of thinking and subsequent new strategies. As Einstein has put it: 'We must learn to see the world anew'. The relatively new scientific discipline "Complexity science" can give more direction to this and is the metaphorical open door that should not go unnoticed in view of the burn care of the future. Complexity sciences studies 'why the whole is more than the sum of the parts'. It studies how multiple separate components interact with each other and their environment and how these interactions lead to 'behavior of the system'. Biological systems are always part of smaller and larger systems and exhibit the behavior of adaptivity, hence the name complex adaptive systems. From the perspective of complexity science, a severe burn injury is an extreme disruption of the 'human body system'. But this disruption also applies to the systems at the organ and cellular level. All these systems follow principles of complex systems. Awareness of the scaling process at multilevel helps to understand and manage the complex situation when dealing with severe burn cases. The aim of this paper is to create awareness of the concept of complexity and to demonstrate the value and possibilities of complexity science methods and tools for the future of burn care through examples from preclinical, clinical, and organizational perspective in burn care.

Approaches to Surgical Debridement in Necrotizing Soft Tissue Infections: Outcomes of an Animated, Interactive Survey

Background

Necrotizing soft tissue infections (NSTI) affect long-term quality of life in survivors. Different approaches to debridement may influence quality of life. The aim of this study was to assess the current practice of the debridement of NSTI in the Netherlands.

Methods

An animated, interactive online survey was distributed among general surgeons and plastic surgeons in the Netherlands. Two NSTI-cases were presented, followed by questions regarding the preferred surgical approach. Case one described a woman with a swollen, red leg, with signs of sepsis and without visible necrosis. Case two described an immunocompromised man with septic shock syndrome and extensive necrosis.

Results

In total 232 responses were included (143 general surgeons, 89 plastic surgeons). In case one, 32% chose to preserve all skin, while 17% chose to resect all skin above the affected fascia, including normal-looking skin. In case two, all participants resected necrotic skin, and most (88%) also blue discolored skin. While 32% did not resect more than blue discolored and necrotic skin, 35% also resected red-colored skin, and 21% all skin overlying the affected fascia, including normal colored skin. Respondents working in a hospital with a burn center tended to preserve more skin, whereas plastic surgeons chose more often for skin resection compared to general surgeons.

Conclusions

By using a novel approach to a survey, the authors demonstrate the existence of extensive practice variety regarding the approach to debridement of NSTI among Dutch general and plastic surgeons. Consensus is needed, followed by targeted education of surgeons.

Access to burn care in low-and middle-income countries: An assessment of timeliness, surgical capacity, and affordability in a regional referral hospital in Tanzania

This study investigates patients' access to surgical care for burns in a low-and-middle-income setting by studying timeliness, surgical capacity, and affordability. A survey was conducted in a regional referral hospital in Manyara, Tanzania. In total, 67 patients were included. To obtain information on burn victims in need of surgical care, irrespective of time lapsed from the burn injury, both patients with burn wounds and patients with contractures were included. Information provided by patients and/or caregivers was supplemented with data from patient files and interviews with hospital administration and physicians. In the burn wound group, 50 percent reached a facility within 24 hours after the injury. Referrals from other health facilities to the regional referral hospital were made within three weeks for 74 percent in this group. Of contracture patients, seventy four percent, had sought healthcare after the acute burn injury. Of the same group, only 4 percent had been treated with skin grafts beforehand, and 70 percent never received surgical care or a referral. Combined, both groups indicated that lack of trust, surgical capacity, and referral timeliness were important factors negatively impacting patient access to surgical care. Accounting for hospital fees indicated patients routinely exceeded the catastrophic expenditure threshold. It was determined that healthcare for burn victims is without financial risk protection. We recommend strengthening burn care and reconstructive surgical programs in similar settings, using a more comprehensive health systems approach to identify and address both medical and socio-economic factors that determine patient mortality and disability.

Scar quality in children with burns 5-7 years after injury: A cross-sectional multicentre study

Long-term scar formation is an important adverse consequence in children with burns, however, information regarding scar quality in the long-term is lacking. Therefore, we evaluated scar quality and its predictors in children with burns 5-7 years after injury. Parents of children with mild/intermediate burns (≤10% total body surface area burned), and of children with severe burns (>10% burned) completed the patient scale of the Patient and Observer Scar Assessment Scale (POSAS 2.0) for their children's-in their opinion-worst scar 5-7 years post-burn. Outcomes and predictive factors of scar quality were studied, and, for children with severe burns, POSAS parent scores were compared with observer scores. We included 103 children with mild/intermediate burns and 28 with severe burns (response rate: 51%). Most children (87%) had scars that differed from normal skin, with most differences reported for colour, and least for pain. Except for colour, children with severe burns had significantly higher scores (difference 0-2 points) on all scar characteristics (representing poorer scar quality) compared with children with mild/intermediate burns. Parent POSAS scores were on average 2.0-2.6 points higher compared to observer scores. Number of surgeries predicted both the mean POSAS and the mean overall opinion of a scar. In conclusion, 5-7 years post-burn, the scar of the majority of children differed from normal skin, especially on the characteristic colour. The uncovered insights are useful in counselling of children and their parents on expectations of the final outcome of their (children's) scar(s), and help in further targeting scar prevention strategies for the individual child.

[What is the stat of art in 3D bioprinting of cartilage? Challenges concerning the reconstruction of a burned ear]

Five years ago in this journal we described our research into 3D bioprinting of ear cartilage for the purpose of making personalized cartilage implants for facial reconstruction. 3D bioprinting makes it possible to place living cells in a biodegradable scaffold to give a 3D structure to the tissue. We are able to develop a hybrid auricular cartilage implant model. However, Long term in vivo experiments are needed to test preclinical applicability. Nevertheless, the work presented in our studies provides a potential strategy for the use of biofabricated tissue constructs in the clinic. In short, 3D bioprinting is still in its infancy and has no direct clinical application yet. Before the step to the clinic can be made, the technique still has to go through a preclinical phase in which it is investigated how the 3D printed tissue would appear in vivo.

A photo-crosslinkable cartilage-derived extracellular matrix bioink for auricular cartilage tissue engineering

Three-dimensional (3D) bioprinting of patient-specific auricular cartilage constructs could aid in the reconstruction process of traumatically injured or congenitally deformed ear cartilage. To achieve this, a hydrogel-based bioink is required that recapitulates the complex cartilage microenvironment. Tissue-derived decellularized extracellular matrix (dECM)-based hydrogels have been used as bioinks for cell-based 3D bioprinting because they contain tissue-specific ECM components that play a vital role in cell adhesion, growth, and differentiation. In this study, porcine auricular cartilage tissues were isolated and decellularized, and the decellularized cartilage tissues were characterized by histology, biochemical assay, and proteomics. This cartilage-derived dECM (cdECM) was subsequently processed into a photo-crosslinkable hydrogel using methacrylation (cdECMMA) and mixed with chondrocytes to create a printable bioink. The rheological properties, printability, and in vitro biological properties of the cdECMMA bioink were examined. The results showed cdECM was obtained with complete removal of cellular components while preserving major ECM proteins. After methacrylation, the cdECMMA bioinks were printed in anatomical ear shape and exhibited adequate mechanical properties and structural integrity. Specifically, auricular chondrocytes in the printed cdECMMA hydrogel constructs maintained their viability and proliferation capacity and eventually produced cartilage ECM components, including collagen and glycosaminoglycans (GAGs). The potential of cell-based bioprinting using this cartilage-specific dECMMA bioink is demonstrated as an alternative option for auricular cartilage reconstruction.

Persistent Systemic Inflammation in Patients With Severe Burn Injury Is Accompanied by Influx of Immature Neutrophils and Shifts in T Cell Subsets and Cytokine Profiles

Severe burn injury causes local and systemic immune responses that can persist up to months, and can lead to systemic inflammatory response syndrome, organ damage and long-term sequalae such as hypertrophic scarring. To prevent these pathological conditions, a better understanding of the underlying mechanisms is essential. In this longitudinal study, we analyzed the temporal peripheral blood immune profile of 20 burn wound patients admitted to the intensive care by flow cytometry and secretome profiling, and compared this to data from 20 healthy subjects. The patient cohort showed signs of systemic inflammation and persistently high levels of pro-inflammatory soluble mediators, such as IL-6, IL-8, MCP-1, MIP-1β, and MIP-3α, were measured. Using both unsupervised and supervised flow cytometry techniques, we observed a continuous release of neutrophils and monocytes into the blood for at least 39 days. Increased numbers of immature neutrophils were present in peripheral blood in the first three weeks after injury (0.1–2.8 × 10⁶/ml after burn vs. 5 × 10³/ml in healthy controls). Total lymphocyte numbers did not increase, but numbers of effector T cells as well as regulatory T cells were increased from the second week onward. Within the CD4⁺ T cell population, elevated numbers of CCR4⁺CCR6^- and CCR4⁺CCR6⁺ cells were found. Altogether, these data reveal that severe burn injury induced a persistent innate inflammatory response, including a release of immature neutrophils, and shifts in the T cell composition toward an overall more pro-inflammatory phenotype, thereby continuing systemic inflammation and increasing the risk of secondary complications.

The effect of TGFβRI inhibition on fibroblast heterogeneity in hypertrophic scar 2D in vitro models

In burn patients, wound healing is often accompanied by hypertrophic scarring (HTS), resulting in both functional and aesthetic problems. HTSs are characterized by abundant presence of myofibroblasts (MFs) residing in the dermis. HTS development and MF persistence is primarily regulated by TGF-β signalling. A promising method to target the transforming growth factor receptor I (TGFβRI; also known as activin-like kinase 5 (ALK5)) is by making use of exon skipping through antisense oligonucleotides. In HTS the distinguishing border between the papillary dermis and the reticular dermis is completely abrogated, thus exhibiting a one layered dermis containing a heterogenous fibroblast population, consisting of papillary fibroblasts (PFs), reticular fibroblasts (RFs) and MFs. It has been proposed that PFs, as opposed to RFs, exhibit anti-fibrotic properties. Currently, it is still unclear which fibroblast subtype is most affected by exon skipping treatment. Therefore, the aim of this study was to investigate the effect of TGFβRI inhibition by exon skipping in PF, RF and HTS fibroblast monocultures. Morphological analyses revealed the presence of a PF-like population after exon skipping in the different fibroblast cultures. This observation was further confirmed by the expression of genes specific for PFs, demonstrated by qPCR analyses. Further investigations on mRNA and protein level revealed that indeed MFs and to a lesser extent RFs are targeted by exon skipping. Furthermore, collagen gel contraction analysis showed that ALK5 exon skipping reduced TGF-β- induced contraction together with decreased alpha-smooth muscle actin expression levels. In conclusion, we show for the first time that exon skipping primarily targets pro-fibrotic fibroblasts. This could be a promising step towards reduced HTS development of burn tissue.

A photo-crosslinkable cartilage-derived extracellular matrix bioink for auricular cartilage tissue engineering

Three-dimensional (3D) bioprinting of patient-specific auricular cartilage constructs could aid in the reconstruction process of traumatically injured or congenitally deformed ear cartilage. To achieve this, a hydrogel-based bioink is required that recapitulates the complex cartilage microenvironment. Tissue-derived decellularized extracellular matrix (dECM)-based hydrogels have been used as bioinks for cell-based 3D bioprinting because they contain tissue-specific ECM components that play a vital role in cell adhesion, growth, and differentiation. In this study, porcine auricular cartilage tissues were isolated and decellularized, and the decellularized cartilage tissues were characterized by histology, biochemical assay, and proteomics. This cartilage-derived dECM (cdECM) was subsequently processed into a photo-crosslinkable hydrogel using methacrylation (cdECMMA) and mixed with chondrocytes to create a printable bioink. The rheological properties, printability, and in vitro biological properties of the cdECMMA bioink were examined. The results showed cdECM was obtained with complete removal of cellular components while preserving major ECM proteins. After methacrylation, the cdECMMA bioinks were printed in anatomical ear shape and exhibited adequate mechanical properties and structural integrity. Specifically, auricular chondrocytes in the printed cdECMMA hydrogel constructs maintained their viability and proliferation capacity and eventually produced cartilage ECM components, including collagen and glycosaminoglycans (GAGs). The potential of cell-based bioprinting using this cartilage-specific dECMMA bioink is demonstrated as an alternative option for auricular cartilage reconstruction.

Effective enzymatic debridement of burn wounds depends on the denaturation status of collagen

The treatment of burn wounds by enzymatic debridement using bromelain has shown promising results in our burn center. However, inadequate debridement occurred in a few cases in which the etiology of the burn was attributed to relatively low temperature burns. We hypothesized that bromelain is ineffective in burns in which collagen denaturation, which occurs approximately at 65°C, has not taken place. Our objective was to assess whether there is a relationship between the denaturation of collagen and the ability of bromelain to debride acute scald burn wounds of different temperatures. Ex vivo human skin from four different donors was cut into 1x1 cm samples, and scald burns were produced by immersion in water at temperatures of 40°C, 50°C, 60°C, 70°C, and 100°C for 20 minutes. Denaturation of collagen was assessed with histology, using hematoxylin and eosin (H&E) staining and a fluorescently labeled collagen hybridizing peptide (CHP), and with second harmonic generation (SHG) microscopy. Burned samples and one control sample (room temperature) were weighed before and after application of enzymatic debridement to assess the efficacy of enzymatic debridement. After enzymatic debridement, a weight reduction of 80% was seen in the samples heated to 70°C and 100°C, whereas the other samples showed a reduction of 20%. Unfolding of collagen, loss of basket-weave arrangement, and necrosis was seen in samples heated to 60°C or higher. Evident CHP fluorescence, indicative of collagen denaturation, was seen in samples of 60°C, 70°C and 100°C. SHG intensity, signifying intact collagen, was significantly lower in the 70°C and 100°C group (P <.05) compared to the lower temperatures. In conclusion, denaturation of collagen in skin samples occurred between 60°C and 70°C and strongly correlated with the efficacy of enzymatic debridement. Therefore, enzymatic debridement with the use of bromelain is ineffective in scald burns lower than 60°C.

Label-free stimulated Raman scattering imaging reveals silicone breast implant material in tissue

Millions of women worldwide have silicone breast implants. It has been reported that implant failure occurs in approximately a tenth of patients within 10 years, and the consequences of dissemination of silicone debris are poorly understood. Currently, silicone detection in histopathological slides is based on morphological features as no specific immunohistochemical technique is available. Here, we show the feasibility and sensitivity of stimulated Raman scattering (SRS) imaging to specifically detect silicone material in stained histopathological slides, without additional sample treatment. Histology slides of four periprosthetic capsules from different implant types were obtained after explantation, as well as an enlarged axillary lymph node from a patient with a ruptured implant. SRS images coregistered with bright-field images revealed the distribution and quantity of silicone material in the tissue. Fast and high-resolution imaging of histology slides with molecular specificity using SRS provides an opportunity to investigate the role of silicone debris in the pathophysiology of implant-linked diseases.

Validity of thermography for measuring burn wound healing potential

Accurate assessment of burn wound depth and the associated healing potential is vital in determining the need for surgical treatment in burns. Infrared thermography measures the temperature of the burn wound noninvasively, thereby providing indirect information on its blood flow. Previous research demonstrated that a small, low‐priced, handheld thermal imager has an excellent reliability, but a moderate validity for measuring burn wound healing potential. A new and more sensitive version of this convenient device has become available. The aim of this study was to evaluate the validity of thermography for measuring burn wound healing potential, compared to Laser Doppler Imaging (LDI) as a reference standard. Thermal images and LDI scans were obtained from burn wounds between 2 and 5 days postburn. Temperature differences between burned and nonburned skin (ΔT) were calculated. To evaluate validity, ΔT values were compared to the healing potential categories assessed by LDI. Two receiver operating characteristic curves were created and two ΔT cutoff values were calculated to illustrate the ability to discriminate between burn wounds that heal in a time period of less than 14 days, between 14 and 21 days, and more than 21 days. Between June and October 2018, 43 burn wounds in 32 patients were measured. ΔT cutoff values of 0.6°C (sensitivity 68%, specificity 95%) and −2.3°C (sensitivity 30%, specificity 95%) were calculated to discriminate between burn wounds that heal in <14 and ≥14 days, and burn wound that heal in ≤21 and >21 days, respectively. This study shows a good validity of the feasible thermal imager for the assessment of burn wound healing potential. Therefore, we consider it a promising technique to be used for triage in local hospitals and general practices, and as a valuable addition to clinical evaluation in burn centers.

[Complexity of disease; a modern view in times of ageing populations and multimorbidity]

Complexity of patient care is rapidly increasing as a consequence of rising numbers of patients with complex multimorbidity. Not just the patient as a whole, but also the networks of organs, tissues and cells are forming a complex adaptive system (CAS). A CAS is defined as a network of several components ('agents') with lots of mutual feedback loops between which there are circular causalities; the predictability of a CAS is limited by definition. However, current guidelines and evidence-based medicine assume that diseases and the medical interventions to address them are predictable. Physicians' brains are complex neural networks that are much better at dealing with complex situations than guidelines. In the near future, physicians will also get help from advanced computer simulation models that make better diagnostic analyses on the basis of detailed phenotyping and are more accurate when predicting possible courses of disease and treatment outcomes.

Skin bioprinting: the future of burn wound reconstruction?

Burns are a significant cause of trauma, and over the years, the focus of patient care has shifted from just survival to facilitation of improved functional outcomes. Typically, burn treatment, especially in the case of extensive burn injuries, involves surgical excision of injured skin and reconstruction of the burn injury with the aid of skin substitutes. Conventional skin substitutes do not contain all skin cell types and do not facilitate recapitulation of native skin physiology. Three-dimensional (3D) bioprinting for reconstruction of burn injuries involves layer-by-layer deposition of cells along with scaffolding materials over the injured areas. Skin bioprinting can be done either in situ or in vitro. Both these approaches are similar except for the site of printing and tissue maturation. There are technological and regulatory challenges that need to be overcome for clinical translation of bioprinted skin for burn reconstruction. However, the use of bioprinting for skin reconstruction following burns is promising; bioprinting will enable accurate placement of cell types and precise and reproducible fabrication of constructs to replace the injured or damaged sites. Overall, 3D bioprinting is a very transformative technology, and its use for wound reconstruction will lead to a paradigm shift in patient outcomes. In this review, we aim to introduce bioprinting, the different stages involved, in vitro and in vivo skin bioprinting, and the various clinical and regulatory challenges in adoption of this technology.

Long-term scar quality after hydrosurgical versus conventional debridement of deep dermal burns (HyCon trial): study protocol for a randomized controlled trial

Background

Deep dermal burns require tangential excision of non-viable tissue and skin grafting to improve wound healing and burn-scar quality. Tangential excision is conventionally performed with a knife, but during the last decade hydrosurgery has become popular as a new tool for tangential excision. Hydrosurgery is generally thought to be a more precise and controlled manner of burn debridement leading to preservation of viable tissue and, therefore, better scar quality. Although scar quality is considered to be one of the most important outcomes in burn surgery today, no randomized controlled study has compared the effect of these two common treatment modalities with scar quality as a primary outcome. The aim of this study is, therefore, to compare long-term scar quality after hydrosurgical versus conventional tangential excision in deep dermal burns.

Methods/design

A multicenter, randomized, intra-patient, controlled trial will be conducted in the Dutch burn centers of Rotterdam, Beverwijk, and Groningen. All patients with deep dermal burns that require excision and grafting are eligible. Exclusion criteria are: a burn wound < 50 cm², total body surface area (TBSA) burned > 30%, full-thickness burns, chemical or electrical burns, infected wounds (clinical symptoms in combination with positive wound swabs), insufficient knowledge of the Dutch or English language, patients that are unlikely to comply with requirements of the study protocol and follow-up, and patients who are (temporarily) incompetent because of sedation and/or intubation. A total of 137 patients will be included. Comparable wound areas A and B will be appointed, randomized and either excised conventionally with a knife or with the hydrosurgery system. The primary outcome is scar quality measured by the observer score of the Patient and Observer Scar Assessment Scale (POSAS); a subjective scar-assessment instrument, consisting of two separate six-item scales (observer and patient) that are both scored on a 10-point rating scale.

Discussion

This study will contribute to the optimal surgical treatment of patients with deep dermal burn wounds.

Trial registration

Dutch Trial Register, NTR6232. Registered on 23 January 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2599-2) contains supplementary material, which is available to authorized users.

The pedicled internal pudendal artery perforator (PIPAP) flap for ischial pressure sore reconstruction: Technique and long-term outcome of a cohort study

BACKGROUND

The ischial region is the site most affected by pressure sores and has the highest recurrence and complication rates compared to other affected sites. We developed a practical and safe pedicled flap for reconstruction of ischial pressure sores based on the rich available perforators from the internal pudendal artery and the surplus of skin at the infragluteal fold.

METHODS

A retrospective cohort study was conducted in all patients who underwent ischial pressure ulcer reconstruction using the PIPAP flap between March 2010 and March 2017. The skin flap was designed along the gluteal fold. The skin perforators of the pudendal artery were marked with a Doppler probe in the medial region of the gluteal fold. Surgery was performed in the jackknife position, and flaps were elevated in the suprafascial plane. Patients were assessed for minor (requiring no additional surgery) and major complications (requiring additional surgery).

RESULTS

Twenty-seven patients (34 flaps) were identified. The median follow-up period was 38 months (IQR 37). Primary closure of the donor-site was achieved in all procedures, only one flap required muscle flap transposition in order to fill the dead space. The mean operating time was 60 ± 21 minutes. In six flaps (9%) wound healing problems were noted that did not require an additional operative procedure. Among the nine flaps (27%) that required a second procedure, 3 (9%) were necessary due to recurrent ulcers.

CONCLUSIONS

The PIPAP flap is a safe and reliable alternative for ischial pressure sore reconstruction, certainly when compared to available techniques. Moreover, it has significant advantages over other techniques including minimal donor-site morbidity, preservation of posterior thigh skin, buttock-line integrity and reliable vascularity.

In vivo polarization-sensitive optical coherence tomography of human burn scars: birefringence quantification and correspondence with histologically determined collagen density

Obtaining adequate information on scar characteristics is important for monitoring their evolution and the effectiveness of clinical treatment. The aberrant type of collagen in scars may give rise to specific birefringent properties, which can be determined using polarization-sensitive optical coherence tomography (PS-OCT). The aim of this pilot study was to evaluate a method to quantify the birefringence of the scanned volume and correlate it with the collagen density as measured from histological slides. Five human burn scars were measured in vivo using a handheld probe and custom-made PS-OCT system. The local retardation caused by the tissue birefringence was extracted using the Jones formalism. To compare the samples, histograms of birefringence values of each volume were produced. After imaging, punch biopsies were harvested from the scar area of interest and sent in for histological evaluation using Herovici polychrome staining. Two-dimensional en face maps showed higher birefringence in scars compared to healthy skin. The Pearson's correlation coefficient for the collagen density as measured by histology versus the measured birefringence was calculated at r=0.80 (p=0.105). In conclusion, the custom-made PS-OCT system was capable of in vivo imaging and quantifying the birefringence of human burn scars, and a nonsignificant correlation between PS-OCT birefringence and histological collagen density was found.

Neutrophil extracellular traps coincide with a pro-coagulant status of microcirculatory endothelium in burn wounds

Burn-induced tissue loss is partly related to secondary expansion of necrosis into vital dermis neighboring the initial burn injury. An important factor herein is the severe loss of perfusion of the burn wound, probably caused by microvascular damage induced by the intense local inflammatory responses as well as burn-induced hypercoagulation. We hypothesize that the formation of neutrophilic extracellular traps (NETs) play an important role in this. The purpose of this study was to investigate postburn intravascular thrombosis, NETs formation and the coagulant state in the microvasculature of burns in both animal models and patients. We used two in vivo burn wound models: rats and pigs. In rats, the entire wound was excised at day 14 postburn and in pigs burn wound biopsies were collected at different time points up to 60 days postburn. To confirm the data in patients, eschar from the burn wound was obtained from burn wound patients at different time points after wounding. The number of intravascular thrombi, the presence of intravascular NETs and the number of tissue factor (TF) positive blood vessels in the burn wound was determined. In rats, a significant increase in intravascular thrombi and TF expression was observed 14 days postburn, that in majority coincided with NETs. In pigs, a significant increase in intravascular thrombi and TF expression was found over time up to 60 days postburn, that in majority coincided with NETs too. Also in eschar of burn wound patients, a significant increase in intravascular thrombi was noted, that in majority coincided with NETs, already 0.5 days postburn and remained elevated up to 46 days postburn. This study shows the presence of NETosis in microcirculatory thrombosis of burn wounds and a switch in the microcirculatory endothelium toward a procoagulant phenotype.

The role of complement in the acute phase response after burns

Severe burns induce a complex systemic inflammatory response characterized by a typical prolonged acute phase response (APR) that starts approximately 4-8h after-burn and persists for months up to a year after the initial burn trauma. During this APR, acute phase proteins (APPs), including C-reactive protein (CRP) and complement (e.g. C3, C4 and C5) are released in the blood, resulting amongst others, in the recruitment and migration of inflammatory cells. Although the APR is necessary for proper wound healing, a prolonged APR can induce local tissue damage, hamper the healing process and cause negative systemic effects in several organs, including the heart, lungs, kidney and the central nervous system. In this review, we will discuss the role of the APR in burns with a specific focus on complement.

A mathematical model for the simulation of the contraction of burns

A continuum hypothesis-based model is developed for the simulation of the contraction of burns in order to gain new insights into which elements of the healing response might have a substantial influence on this process. Tissue is modeled as a neo-Hookean solid. Furthermore, (myo)fibroblasts, collagen molecules, and a generic signaling molecule are selected as model components. An overview of the custom-made numerical algorithm is presented. Subsequently, good agreement is demonstrated with respect to variability in the evolution of the surface area of burns over time between the outcomes of computer simulations and measurements obtained in an experimental study. In the model this variability is caused by varying the values for some of its parameters simultaneously. A factorial design combined with a regression analysis are used to quantify the individual contributions of these parameter value variations to the dispersion in the surface area of healing burns. The analysis shows that almost all variability in the surface area can be explained by variability in the value for the myofibroblast apoptosis rate and, to a lesser extent, the value for the collagen molecule secretion rate. This suggests that most of the variability in the evolution of the surface area of burns over time in the experimental study might be attributed to variability in these two rates. Finally, a probabilistic analysis is used in order to investigate in more detail the effect of variability in the values for the two rates on the healing process. Results of this analysis are presented and discussed.

A biomechanical mathematical model for the collagen bundle distribution-dependent contraction and subsequent retraction of healing dermal wounds

A continuum hypothesis-based, biomechanical model is presented for the simulation of the collagen bundle distribution-dependent contraction and subsequent retraction of healing dermal wounds that cover a large surface area. Since wound contraction mainly takes place in the dermal layer of the skin, solely a portion of this layer is included explicitly into the model. This portion of dermal layer is modeled as a heterogeneous, orthotropic continuous solid with bulk mechanical properties that are locally dependent on both the local concentration and the local geometrical arrangement of the collagen bundles. With respect to the dynamic regulation of the geometrical arrangement of the collagen bundles, it is assumed that a portion of the collagen molecules are deposited and reoriented in the direction of movement of (myo)fibroblasts. The remainder of the newly secreted collagen molecules are deposited by ratio in the direction of the present collagen bundles. Simulation results show that the distribution of the collagen bundles influences the evolution over time of both the shape of the wounded area and the degree of overall contraction of the wounded area. Interestingly, these effects are solely a consequence of alterations in the initial overall distribution of the collagen bundles, and not a consequence of alterations in the evolution over time of the different cell densities and concentrations of the modeled constituents. In accordance with experimental observations, simulation results show furthermore that ultimately the majority of the collagen molecules ends up permanently oriented toward the center of the wound and in the plane that runs parallel to the surface of the skin.

Insights into the use of thermography to assess burn wound healing potential: a reliable and valid technique when compared to laser Doppler imaging

Adequate assessment of burn wounds is crucial in the management of burn patients. Thermography, as a noninvasive measurement tool, can be utilized to detect the remaining perfusion over large burn wound areas by measuring temperature, thereby reflecting the healing potential (HP) (i.e., number of days that burns require to heal). The objective of this study was to evaluate the clinimetric properties (i.e., reliability and validity) of thermography for measuring burn wound HP. To evaluate reliability, two independent observers performed a thermography measurement of 50 burns. The intraclass correlation coefficient (ICC), the standard error of measurement (SEM), and the limits of agreement (LoA) were calculated. To assess validity, temperature differences between burned and nonburned skin (?T) were compared to the HP found by laser Doppler imaging (serving as the reference standard). By applying a visual method, one ?T cutoff point was identified to differentiate between burns requiring conservative versus surgical treatment. The ICC was 0.99, expressing an excellent correlation between two measurements. The SEM was calculated at 0.22°C, the LoA at ?0.58°C and 0.64°C. The ?T cutoff point was ?0.07°C (sensitivity 80%; specificity 80%). These results show that thermography is a reliable and valid technique in the assessment of burn wound HP.

Reliability and Accuracy of Techniques for Surface Area Measurements of Wounds and Scars

The applicability of simple methods to measure the size of pathological skin lesions for management and research has been poorly studied to date. The interobserver reliability and accuracy (validity) was established for planimetry by photography and planimetry by tracing on a transparent sheet in this study. Drawings of 25, 50, and 75 cm2 were created on 3 locations with increasing curvature (back, thigh, and forearm) in 20 healthy volunteers. Three investigators evaluated the drawings by both planimetry techniques. Both techniques showed a good reliability (r ≥ 0.82, intraclass correlation) for 25 cm2 areas. Planimetry by photography was more reliable than planimetry by tracings for the 50 -and 75-cm2 areas and was more accurate than planimetry by tracing for all areas except for the area with the greatest curvature, the forearm. The study permits the conclusion that planimetry by photography is more suitable for surface area measurements than planimetry by tracing except for extremely curved body parts, where it is likely that effects of distortion supervene.

Cartilage Tissue Engineering: Preventing Tissue Scaffold Contraction Using a 3D-Printed Polymeric Cage

Scaffold contraction is a common but underestimated problem in the field of tissue engineering. It becomes particularly problematic when creating anatomically complex shapes such as the ear. The aim of this study was to develop a contraction-free biocompatible scaffold construct for ear cartilage tissue engineering. To address this aim, we used three constructs: (i) a fibrin/hyaluronic acid (FB/HA) hydrogel, (ii) a FB/HA hydrogel combined with a collagen I/III scaffold, and (iii) a cage construct containing (ii) surrounded by a 3D-printed poly-ɛ-caprolactone mold. A wide range of different cell types were tested within these constructs, including chondrocytes, perichondrocytes, adipose-derived mesenchymal stem cells, and their combinations. After in vitro culturing for 1, 14, and 28 days, all constructs were analyzed. Macroscopic observation showed severe contraction of the cell-seeded hydrogel (i). This could be prevented, in part, by combining the hydrogel with the collagen scaffold (ii) and prevented in total using the 3D-printed cage construct (iii). (Immuno)histological analysis, multiphoton laser scanning microscopy, and biomechanical analysis showed extracellular matrix deposition and increased Young's modulus and thereby the feasibility of ear cartilage engineering. These results demonstrated that the 3D-printed cage construct is an adequate model for contraction-free ear cartilage engineering using a range of cell combinations.

[3D bioprinting of cartilage: challenges concerning the reconstruction of a burned ear]

Reconstruction of a severely maimed ear is a major challenge. The ear is highly flexible yet tough, and has a very complex three-dimensional shape. Reconstruction of a patient's burned ear is even more complex due to surrounding tissue damage. Not only does this hamper reconstruction options, it also increases the likelihood of issues when using synthetic implant materials. In such cases, rib cartilage is the preferred option, but this tissue has practical limitations too. For these reasons, tissue engineering and 3D bioprinting may have the potential to create personalized cartilage implants for burns patients. However, 3D bioprinting is a tool to facilitate the reconstruction, and not by itself the Holy Grail. The clinical application of this technique is still at a very early stage. Nevertheless, we expect that 3D bioprinting can be utilised for facial reconstruction following burns come 2020.

The hand held Doppler device for the detection of perforators in reconstructive surgery: what you hear is not always what you get

BACKGROUND

Perforator-based flaps have become indispensable in the treatment of burn scars. Pre-operative perforator mapping is often performed by use of the hand held Doppler device, partly due to its convenience and the low costs. We expected to find sufficient evidence in literature to support the use of the device, however available literature showed a distinct lack of clinimetric studies that adequately tested the reliability.

METHODS

To assess reliability, perforator locations were mapped independently by two clinicians using an 8MHz Doppler device. In healthy volunteers the elbow region or the peri-umbilical region were randomly chosen to be the measurement areas of predefined squares (7cm×7cm). Subsequently, the perforators within the area were mapped with Duplex to establish the validity by means of the positive predictive value.

RESULTS

20 volunteers were included. The hand held Doppler technique showed moderate reliability with a mean Dice coefficient of 0.56. Also, poor validity was found expressed by a mean positive predictive value of 55%.

CONCLUSIONS

Surprisingly, this study has shown that performance of the hand held Doppler device was moderate. The Doppler should not be used alone for the detection of perforators.

Skin stretching for primary closure of acute burn wounds

BACKGROUND

In burn care, a well-acknowledged problem is the suboptimal scar outcome from skin grafted burn wounds. With the aim of improving this, we focused on a new technique: excision of the burn wound followed by primary closure, thereby using a skin-stretching device to stretch the adjacent healthy skin. The short- and long-term effect of Skin Stretch was compared to split skin grafting (SSG) in a randomized controlled trial.

METHODS

Patients with burn wounds were randomized for SSG or primary wound closure using Skin Stretch. Follow-up was performed at 3 and 12 months postoperatively. The scar surface area was calculated and the scar quality was assessed, using subjective and objective measurement methods.

RESULTS

No significant differences between the SSG and the Skin Stretch group were found for scar surface area. In the Skin Stretch group, a significant reduction of the surface area from 65.4cm(2) (13.6-129.1) to 13.4cm(2) (3.0-36.6) was found at 3 months (p=0.028) and at 12 months postoperatively (65.4cm(2) (13.6-129.1) to 33.0cm(2) (8.9-63.7), p=0.046, Wilcoxon signed ranks test).

CONCLUSIONS

Skin Stretch for primary closure of acute burn wounds is a suitable technique and can be considered for specific circumscript full-thickness burn wounds. However, future research should be performed to provide additional scientific evidence.

Cost study of dermal substitutes and topical negative pressure in the surgical treatment of burns

BACKGROUND

A recently performed randomised controlled trial investigated the clinical effectiveness of dermal substitutes (DS) and split skin grafts (SSG) in combination with topical negative pressure (TNP) in the surgical treatment of burn wounds. In the current study, medical and non-medical costs were investigated, to comprehensively assess the benefits of this new treatment.

METHODS

The primary outcome was mean total costs of the four treatment strategies: SSG with or without DS, and with or without TNP. Costs were studied from a societal perspective. Findings were evaluated in light of the clinical effects on scar elasticity.

RESULTS

Eighty-six patients were included. Twelve months post-operatively, highest elasticity was measured in scars treated with DS and TNP (p=0.027). The initial cost price of treatment with DS and TNP was €2912 compared to treatment with SSG alone €1703 (p<0.001). However, mean total costs per patient did not differ significantly between groups (range €29097-€43774).

DISCUSSION

Costs of the interventional treatment contributed maximal 7% to the total costs and total costs varied widely within and between groups, but were not significantly different. Therefore, in the selection of the most optimal type of surgical intervention, cost considerations should not play an important role.

Outcome after burns: an observational study on burn scar maturation and predictors for severe scarring

Long-term outcome of burn scars as well as the relation with clinically relevant parameters has not been studied quantitatively. Therefore, we conducted a detailed analysis on the clinical changes of burn scars in a longitudinal setup. In addition, we focused on the differences in scar quality in relation to the depth, etiology of the burn wound and age of the patient. Burn scars of 474 patients were subjected to a scar assessment protocol 3, 6, and 12 months postburn. Three different age groups were defined (≤5, 5-18, and ≥18 years). The observer part of the patient and observer scar assessment scale revealed a significant (p < 0.001) improvement in scar quality at 12 months compared with the 3- and 6-month data. Predictors for severe scarring are depth of the wound (p < 0.001) and total body surface area burned (p < 0.001). Etiology (p = 0.753) and age (p > 0.230) have no significant influence on scar quality when corrected for sex, total body surface area burned, time, and age or etiology, respectively.

Clinical effectiveness of dermal substitution in burns by topical negative pressure: a multicenter randomized controlled trial

Previous research has shown clinical effectiveness of dermal substitution; however, in burn wounds, only limited effect has been shown. A problem in burn wounds is the reduced take of the autograft, when the substitute and graft are applied in one procedure. Recently, application of topical negative pressure (TNP) was shown to improve graft take. The aim of this study was to investigate if application of a dermal substitute in combination with TNP improves scar quality after burns. In a four-armed multicenter randomized controlled trial, a split-skin graft with or without a dermal substitute and with or without TNP was compared in patients with deep dermal or full-thickness burns requiring skin transplantation. Graft take and rate of wound epithelialization were evaluated. Three and 12 months postoperatively, scar parameters were measured. The results of 86 patients showed that graft take and epithelialization did not reveal significant differences. Significantly fewer wounds in the TNP group showed postoperative contamination, compared to other groups. Highest elasticity was measured in scars treated with the substitute and TNP, which was significantly better compared to scars treated with the substitute alone. Concluding, this randomized controlled trial shows the effectiveness of dermal substitution combined with TNP in burns, based on extensive wound and scar measurements.

A reliable, non-invasive measurement tool for anisotropy in normal skin and scar tissue

BACKGROUND

Anisotropy of the skin varies depending on different locations and pathological conditions. Currently, no reliable non-invasive measurement tool is available for tissue anisotropy. The Reviscometer is an anisotropy measurement tool that measures the resonance running time (RRT) of a shock wave. This study was initiated to establish the reliability of the Reviscometer on normal skin and scars, and to provide basic information on tissue alignment in normal skin and scars.

METHODS

Fifty volunteers and 50 patients underwent measurements on normal skin and scars, respectively. All measurements were performed by the same two observers. Measurements on normal skin were performed on the forearm, upper arm, and abdomen.

RESULTS

The results showed that the intraclass correlation coefficient of the inter-observer reliability was > or =0.79 on normal skin and > or =0.86 on scars. In normal skin, the highest mean RRT was found on the abdomen (156.4+/-48.8), followed by the upper arm (123.2+/-33.6) and the forearm (112.5+/-24.3). A significantly lower mean RRT was found in scars (52.3+/-21.9) compared with normal skin (91.6+/-37.7).

CONCLUSION

Reviscometer measurements were reliable for normal skin and scars. In addition, clear differences between scars and normal skin but also within different locations on normal skin were identified. The Reviscometer can be considered for the evaluation of the efficacy of different treatments.

Differences in collagen architecture between keloid, hypertrophic scar, normotrophic scar, and normal skin: An objective histopathological analysis

Normotrophic, hypertrophic, and keloidal scars are different types of scar formation, which all need a different approach in treatment. Therefore, it is important to differentiate between these types of scar, not only clinically but also histopathologically. Differences were explored for collagen orientation and bundle thickness in 25 normal skin, 57 normotrophic scar, 56 hypertrophic scar, and 56 keloid biopsies, which were selected on clinical diagnosis. Image analysis was performed by fast fourier transformation. The calculated collagen orientation index ranged from 0 (random orientation) to 1 (parallel orientation). The bundle distance was calculated by the average distance between the centers of the collagen bundles. The results showed that compared with all three types of scars, the collagen orientation index was significantly lower in normal skin, which indicates that scars are organized in a more parallel manner. No differences were found between the different scars. Secondly, compared with normal skin, normotrophic scar, and hypertrophic scar, the bundle distance was significantly larger in keloidal scar, which suggests that thicker collagen bundles are present in keloidal scar. This first extensive histological study showed objective differences between normal skin, normotrophic, hypertrophic, and keloidal scar.