Assessment of burn depth and burn wound healing potential

Negative pressure wound therapy in burns: a prospective, randomized-controlled trial

BACKGROUND

Negative-pressure-wound-therapy (NPWT) has become a widely used tool for the coverage and active treatment of complex wounds, including burns. This study aimed to evaluate the effectiveness of NPWT in acute burns of upper and lower extremities and to compare results to the standard-of-care (SOC) at our institution.

METHODS

Patients that were admitted to our institution between May 2019 and November 2021 with burns on extremities between 0.5 % and 10 % of the total body surface area (%TBSA) were included and randomized to either NPWT or SOC (polyhexanide gel, fatty gauze, and cotton wool). Treatment was performed until complete wound healing. Patients that required skin grafts, received additional NPWT after grafting independent on the initial group allocation.

RESULTS

Sixty-five patients suffering from burn injury between May 2019 and November 2021 were randomized into treatment with NPWT (n = 33) or SOC (n = 32); of these, 33 patients (NPWT) and 28 patients (SOC) had complete data sets and were included in the analysis. Both groups were similar regarding age (39.8 ± 13.7 vs. 44.8 ± 16.2 years,p = 0.192), total burn size (3.1 ± 2.3 vs. 3.4 ± 2.8 %TBSA,p = 0.721) and treated wound size (1.9 ± 1.2 vs. 1.5 ± 0.8 %TBSA,p = 0.138). We found no differences regarding healing time (11.0 ± 4.9 vs. 8.6 ± 3.8,p = 0.074, and significant differences in a number of dressing changes throughout the study (2.4 ± 1.5 vs 4.2 ± 1.9,p < 0.001). The Kaplan-Meier time-to-event analysis exhibited no statistically significant difference in the time to healing or skin grafting (p = 0.085) in NPWT group compared with SOC group. The median time to healing or skin grafting was 10(8-11) days for NPWT and 9(7-11) days for SOC. The hazard ratio for healing or skin graft was HR= 0.64(0.38-1.08). The results of the time-to-event analysis as well as the Kaplan-Meier curve on the PPS confirmed this result. We found no differences in secondary surgical operations 15.2 vs 21.4 % pain or functional outcomes.

CONCLUSIONS

In this study, we found no significant difference between the two groups in terms of time to detect wound healing. We also found no difference regarding further operations for wound closure, pain and/or scarring. However, dressing changes were significantly less frequent for patients that were treated with NPWT, which may be a psychological and logistical advantage.

Visualization enhancement by PCA-based image fusion for skin burns assessment in polarization-sensitive OCT

Polarization-sensitive optical coherence tomography (PS-OCT) is a functional imaging tool for measuring tissue birefringence characteristics. It has been proposed as a potentially non-invasive technique for evaluating skin burns. However, the PS-OCT modality usually suffers from high system complexity and relatively low tissue-specific contrast, which makes assessing the extent of burns in skin tissue difficult. In this study, we employ an all-fiber-based PS-OCT system with single-state input, which is simple and efficient for skin burn assessment. Multiple parameters, such as phase retardation (PR), degree of polarization uniformity (DOPU), and optical axis orientation, are obtained to extract birefringent features, which are sensitive to subtle changes in structural arrangement and tissue composition. Experiments on ex vivo porcine skins burned at different temperatures were conducted for skin burn investigation. The burned depths estimated by PR and DOPU increase linearly with the burn temperature to a certain extent, which is helpful in classifying skin burn degrees. We also propose an algorithm of image fusion based on principal component analysis (PCA) to enhance tissue contrast for the multi-parameter data of PS-OCT imaging. The results show that the enhanced images generated by the PCA-based image fusion method have higher tissue contrast, compared to the en-face polarization images by traditional mean value projection. The proposed approaches in this study make it possible to assess skin burn severity and distinguish between burned and normal tissues.

Acceleration of wound healing using adipose mesenchymal stem cell secretome hydrogel on partial-thickness cutaneous thermal burn wounds: An in vivo study in rats

Background and Aim

The intricate healing process involves distinct sequential and overlapping phases in thermal injury. To maintain the zone of stasis in Jackson's burn wound model, proper wound intervention is essential. The extent of research on the histoarchitecture of thermal wound healing and the application of mesenchymal stem cell (MSC)-free-based therapy is limited. This study aimed to assess the efficacy of MSC-secretome-based hydrogel for treating partial-thickness cutaneous thermal burn wounds.

Materials and Methods

Eighteen male Wistar rats were divided into three groups, namely the hydrogel base (10 mg), hydrogel secretome (10 mg) and Bioplacenton™ (10 mg) treatment groups. All groups were treated twice a day (morning and evening) for 7 days. Skin tissue samples from the animals were processed for histological evaluation using the formalin-fixed paraffin-embedded method on days 3 and 7.

Results

This study's findings showed that secretome hydrogel expedited thermal burn wound healing, decreasing residual burn area, boosting collagen deposition and angiogenesis, guiding scar formation, and influencing the inflammation response facilitated by polymorphonuclear leukocytes and macrophages.

Conclusion

The secretome hydrogel significantly improves healing outcomes in partial-thickness cutaneous thermal burn wounds. The administration of secretome hydrogel accelerates the reduction of the residual burn area and promotes fibroblast proliferation and collagen density. The repairment of histo-architecture of the damaged tissue was also observed such as the reduction of burn depth, increased angiogenesis and epidermal scar index while the decreased dermal scar index. Furthermore, the secretome hydrogel can modulate the immunocompetent cells by decreasing the polymorphonuclear and increasing the mononuclear cells. Thus, it effectively and safely substitutes for thermal injury stem cell-free therapeutic approaches. The study focuses on the microscopical evaluation of secretome hydrogel; further research to investigate at the molecular level may be useful in predicting the beneficial effect of secretome hydrogel in accelerating wound healing.

Topical Noneuphoric Phytocannabinoid Elixir 14 Reduces Inflammation and Mitigates Burn Progression

INTRODUCTION

Thermal injuries are caused by exposure to a wide variety of agents including heat, electricity, radiation, chemicals, and friction. Early intervention can decrease injury severity by preventing excess inflammation and mitigating burn wound progression for improved healing outcomes. Previous studies have demonstrated that cannabinoids can trigger anti-inflammatory responses and promote wound closure. Therefore, the purpose of this study was to investigate whether a topical application of Noneuphoric Phytocannabinoid Elixir 14 (NEPE14) containing a full complement of phytocannabinoids (< 0.3% delta-9-tetrahydrocannabinol or cannabidiol) and other phytochemicals would mitigate burn wound progression in the treatment of deep partial-thickness burn wounds.

METHODS

Deep partial-thickness burns were created on the dorsum of four anesthetized pigs and treated with NEPE14, Vehicle control, Silverlon, or gauze. The burns were assessed on postburn days 4, 7, and 14. Assessments consisted of digital photographs, Laser-Speckle imagery (blood perfusion), MolecuLight imagery (qualitative bacterial load), and biopsies for histology and immunohistochemistry (interleukin six and tumor necrosis factor-α).

RESULTS

Topical treatment with NEPE14 significantly (P < 0.001) decreased inflammation (interleukin six and tumor necrosis factor-α) in comparison to control groups. It was also demonstrated that the reduction in inflammation led to mitigation of burn wound progression. In terms of wound healing and presence of bacteria, no statistically significant differences were observed.

CONCLUSIONS

Topical treatment of deep partial-thickness burns with NEPE14 decreased wound inflammation and mitigated burn wound progression in comparison to control treatments.

Early Enzymatic Burn Debridement: Results of the DETECT Multicenter Randomized Controlled Trial

Since 1970 surgeons have managed deep burns by surgical debridement and autografting. We tested the hypothesis that enzymatic debridement with NexoBrid would remove the eschar reducing surgery and achieve comparable long-term outcomes as standard of care (SOC). In this Phase 3 trial, we randomly assigned adults with deep burns (covering 3-30% of total body surface area [TBSA]) to NexoBrid, surgical or nonsurgical SOC, or placebo Gel Vehicle (GV) in a 3:3:1 ratio. The primary endpoint was complete eschar removal (ER) at the end of the debridement phase. Secondary outcomes were need for surgery, time to complete ER, and blood loss. Safety endpoints included wound closure and 12 and 24-months cosmesis on the Modified Vancouver Scar Scale. Patients were randomized to NexoBrid (n = 75), SOC (n = 75), and GV (n = 25). Complete ER was higher in the NexoBrid versus the GV group (93% vs 4%; P < .001). Surgical excision was lower in the NexoBrid vs the SOC group (4% vs 72%; P < .001). Median time to ER was 1.0 and 3.8 days for the NexoBrid and SOC respectively (P < .001). ER blood loss was lower in the NexoBrid than the SOC group (14 ± 512 mL vs 814 ± 1020 mL, respectively; P < .0001). MVSS scores at 12 and 24 months were noninferior in the NexoBrid versus SOC groups (3.7 ± 2.1 vs 5.0 ± 3.1 for the 12 months and 3.04 ± 2.2 vs 3.30 ± 2.76 for the 24 months). NexoBrid resulted in early complete ER in >90% of burn patients, reduced surgery and blood loss. NexoBrid was safe and well tolerated without deleterious effects on wound closure and scarring.

Pharmaceutical applications of chitosan in skin regeneration: A review

Skin regeneration is the process that restores damaged tissues. When the body experiences trauma or surgical incisions, the skin and tissues on the wound surface become damaged. The body repairs this damage through complex physiological processes to restore the original structural and functional states of the affected tissues. Chitosan, a degradable natural bioactive polysaccharide, has attracted widespread attention partly owing to its excellent biocompatibility and antimicrobial properties; additionally, a modified form of this compound has been shown to promote skin regeneration. This review evaluates the recent research progress in the application of chitosan to promote skin regeneration. First, we discuss the basic principles of the extraction and preparation processes of chitosan from its source. Subsequently, we describe the functional properties of chitosan and the optimization of these properties through modification. We then focus on the existing chitosan-based biomaterials developed for clinical applications and their corresponding effects on skin regeneration, particularly in cases of diabetic and burn wounds. Finally, we explore the challenges and prospects associated with the use of chitosan in skin regeneration. Overall, this review provides a reference for related research and contributes to the further development of chitosan-based products in cutaneous skin regeneration.

Laser speckle contrast imaging, an alternative to laser doppler imaging in clinical practice of burn wound care derivation of a color code

OBJECTIVE

To develop a color code and to investigate the validity of Laser Speckle Contrast Imaging (LSCI) for measuring burn wound healing potential (HP) in burn patients as compared to the reference standard Laser Doppler Imaging (LDI).

METHOD

A prospective, observational, cohort study was conducted in adult patients with acute burn wounds. The relationship between mean flux measured with LDI and mean perfusion units (PU) measured with LSCI was expressed in a regression formula. Measurements were performed between 2 and 5 days after the burn wound. The creation of a LSCI color code was done by mapping the clinically validated color code of the LDI to the corresponding values on the LSCI scale. To assess validity of the LSCI, the ability of the LSCI to discriminate between HP < 14 and ≥ 14 days and HP < 21 and original ≥ 21 days according to the LDI reference standard was evaluated, with calculation of receiver operating characteristics (ROC) curves.

RESULTS

A total of 50 patients were included with a median age of 40 years and total body surface area burned of 6%. LSCI values of 143 PU and 113 PU were derived as the cut-off values for the need of conservative treatment (HP < 14 and ≥ 14 days) resp. surgical closure (HP < 21 and ≥ 21 days). These LSCI cut off values showed a good discrimination between HP 14 days versus ≥ 14 days (Area Under Curve (AUC)= 0.89; sensitivity 85% and specificity = 82%) and a good discrimination between HP 21 days versus ≥ 21 days (AUC of 0.89, sensitivity 81% and specificity 88%).

CONCLUSION

This is the first study in which a color code for the LSCI in adult clinical burn patients has been developed. Our study reconfirms the good performance of the LSCI for prediction of burn wound healing potential. This provides additional evidence for the potential value of the LSCI in specialized burn care.

Multi-Class Wound Classification via High and Low-Frequency Guidance Network

Wound image classification is a crucial preprocessing step to many intelligent medical systems, e.g., online diagnosis and smart medical. Recently, Convolutional Neural Network (CNN) has been widely applied to the classification of wound images and obtained promising performance to some extent. Unfortunately, it is still challenging to classify multiple wound types due to the complexity and variety of wound images. Existing CNNs usually extract high- and low-frequency features at the same convolutional layer, which inevitably causes information loss and further affects the accuracy of classification. To this end, we propose a novel High and Low-frequency Guidance Network (HLG-Net) for multi-class wound classification. To be specific, HLG-Net contains two branches: High-Frequency Network (HF-Net) and Low-Frequency Network (LF-Net). We employ pre-trained models ResNet and Res2Net as the feature backbone of the HF-Net, which makes the network capture the high-frequency details and texture information of wound images. To extract much low-frequency information, we utilize a Multi-Stream Dilation Convolution Residual Block (MSDCRB) as the backbone of the LF-Net. Moreover, a fusion module is proposed to fully explore informative features at the end of these two separate feature extraction branches, and obtain the final classification result. Extensive experiments demonstrate that HLG-Net can achieve maximum accuracy of 98.00%, 92.11%, and 82.61% in two-class, three-class, and four-class wound image classifications, respectively, which outperforms the previous state-of-the-art methods.

The Use of Laser Doppler Imaging in Nitric Acid Burns: A Case Report and Literature Review

Laser Doppler imaging (LDI) technology has been validated to assess thermal burn depth by predicting wound healing potential. However, there is no clear evidence for its use in chemical burns. We present a case of an 8% total burn surface area (TBSA) nitric acid burn following an industrial accident, in an otherwise healthy 36-year-old man. LDI assessment was suggestive of poor healing potential of >21 days, warranting surgical management. However, conservative management was opted for based on clinical assessment as the wound eschar appeared thin and more consistent with epithelial staining. Patient follow-up confirmed a total burn healing time of two months, suggesting that the LDI assessment was accurate. A comprehensive literature review was performed using the MEDLINE (PubMed) database to identify animal or clinical studies evaluating the efficacy of LDI in chemical burns. A qualitative synthesis of our findings is presented. We identified two experimental studies in porcine models with sulfur mustard burns, each confirming the accuracy of LDI assessment when compared to the histopathology findings. Limited experimental animal studies on the use of LDI suggest similar validity in chemical burns, and this correlates with the clinical outcome in this case. However, this alone is insufficient to prove its validity and define its role in the assessment of chemical burns. Clinical trials are required to further assess and define the parameters of LDI use and efficacy in this context.

A Deep Learning Image-to-Image Translation Approach for a More Accessible Estimator of the Healing Time of Burns

OBJECTIVE

An accurate and timely diagnosis of burn severity is critical to ensure a positive outcome. Laser Doppler imaging (LDI) has become a very useful tool for this task. It measures the perfusion of the burn and estimates its potential healing time. LDIs generate a 6-color palette image, with each color representing a healing time. This technique has very high costs associated. In resource-limited areas, such as low- and middle-income countries or remote locations like space, where access to specialized burn care is inadequate, more affordable and portable tools are required. This study proposes a novel image-to-image translation approach to estimate burn healing times, using a digital image to approximate the LDI.

METHODS

This approach consists of a U-net architecture with a VGG-based encoder and applies the concept of ordinal classification. Paired digital and LDI images of burns were collected. The performance was evaluated with 10-fold cross-validation, mean absolute error (MAE), and color distribution differences between the ground truth and the estimated LDI.

RESULTS

Results showed a satisfactory performance in terms of low MAE ( 0.2370 ±0.0086). However, the unbalanced distribution of colors in the data affects this performance.

SIGNIFICANCE

This novel and unique approach serves as a basis for developing more accessible support tools in the burn care environment in resource-limited areas.

ICG-mediated fluorescence-assisted debridement to promote wound healing

The purpose of this study was to examine the efficacy of ICG-mediated fluorescence molecular imaging (FMI) in debridement of necrotic tissue. 96 wound-infected rats were randomly divided into control group, ICG group, excitation light (EL)group and FMI group for debridement of necrotic tissue (n = 24). (I) Control group: only debridement; (II) ICG group: ICG injection before debridement; (III) EL group: Debridement under EL; (IV) FMI group: Debridement guided by ICG-mediated FMI. On the 3rd, 6th, and 9th days, the wound tissues of the rats in each group were collected for histological examination, and the levels of serum interleukin-4 (IL-4) and interferon-γ (INF-γ) were analyzed. The wound healing rate, wound score and body weight of the rats in each group were followed up until the wound healed. The results showed that the infected wounds of the rats in the FMI group had significant fluorescence development. The level of serum IL-4 in the FMI group was higher than that in the other three groups on the 6th day (p<0.01), while the level of INF-γ was lower than that in the other three groups on the 6th and 9th day (p<0.05). The results of dynamic wound tissue H&E staining indicated that the wound healing in the FMI group was better than the other three groups. The in vivo follow-up results showed that the wound healing rate and wound score of the FMI group were better than the other three groups, and the growth of rats had no difference with the other groups. ICG-mediated FMI can achieve accurate imaging of necrotic tissue for debridement, and so can accelerate wound healing, which has good clinical application prospects.

The Burn Wound

Skin serves as a protective barrier against infection, prevents excessive fluid and electrolyte losses, performs crucial thermoregulation, and provides tactile feedback of surroundings. The skin also plays an essential role in human perception of body image, personal appearance, and self-confidence. With these many diverse functions, understanding normal anatomic composition of skin is pivotal to evaluating the extent of its disruption from burn injury. This article discusses the pathophysiology, initial evaluation, subsequent progression, and healing of burn wounds. By delineating the various microcellular and macrocellular alterations of burn injury, this review also augments providers' capacity to deliver patient-centered, evidence-based burn care.

Agreement of clinical assessment of burn size and burn depth between referring hospitals and burn centres: A systematic review

BACKGROUND

The quality of burn care is highly dependent on the initial assessment and care. The aim of this systematic review was to investigate the agreement of clinical assessment of burn depth and %TBSA between the referring units and the receiving burn centres.

METHODS

Included articles had to meet criteria defined in a PICO (patients, interventions, comparisons, outcomes). Relevant databases were searched using a predetermined search string (November 6th 2021). Data were extracted in a standardised fashion. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach for test accuracy was used to assess the certainty of evidence. The QUADAS-2 tool was used to assess the risk of bias of individual studies as 'high', 'low' or 'unclear'.

RESULTS

A total of 412 abstracts were retrieved and of these 28 studies with a total of 6461 patients were included, all reporting %TBSA and one burn depth. All studies were cross-sectional and most of them comprising retrospectively enrolled consecutive cohort. All studies showed a low agreement between %TBSA calculations made at referring units and at burn centres. Most studies directly comparing estimations of %TBSA at referring institutions and burn centers showed a proportion of overestimations of 50% or higher. The study of burn depth showed that 55% were equal to the estimates from the burn centre. Most studies had severe study limitations and the risk of imprecision was high. The overall certainty of evidence for accuracy of clinical estimations in referring centres is low (GRADE ⊕⊕ОО) for %TBSA and very low (GRADE ⊕ООО) for burn depth and resuscitation.

CONCLUSION

Overestimation of %TBSA at referring hospitals occurs very frequently. The overall certainty of evidence for accuracy of clinical estimations in referring centres is low for burn size and very low for burn depth. The findings suggest that the burn community has a significant challenge in educating and communicating better with our colleagues at referring institutions and that high-quality studies are needed.

Modified Colson flap with subcutaneous liposuction for one-stage donor site removal: A case series

OBJECTIVES

The aim of this study was to evaluate the functional and cosmetic results of an innovative procedure for modified Colson flap-graft consisting of immediate defatting of the flap by a liposuction cannula.

METHODS

A cross-sectional study was performed among patients with deep hand burns requiring a modified Colson flap between 2018 and 2021. Outcomes included functional and cosmetic assessment of the hand through a quality-of-life questionnaire, a sensitivity scale and a scar assessment scale.

RESULTS

During this period, 7 patients were operated on using our technique. One patient was lost to follow-up; 7 patients with a median age of 44 years were included, with a total of 10 burned hands. The burns were thermal in 5 out of 7 cases and the coverage concerned the whole hand in 50% of the cases. The flaps all received cannula defatting. The median time to flap weaning was 23 days (20 to 30 days). The median follow-up was 16 months. One case required remote flap weaning. The median POSAS (Patient and Observer Scar Assessment Scale) per patient was 4 and 2 per observer. The median BMRCSS (British Medical Research Council Sensory Scale) was 122. One case had recovered S2 sensitivity, the other cases had S3 or S4 sensitivity.

CONCLUSION

Immediate defatting is one of the factors in tegumental quality allowing rapid functional recovery of the hand. The cannula defatting technique does not appear to require additional defatting time. The use of the liposuction cannula allows a one-step, homogeneous, and easier defatting, with a lower risk of devascularization.

Cholecalciferol-load films for the treatment of nasal burns caused by cauterization of the hypertrophied inferior turbinate: formulation, in vivo study, and clinical assessment

Nasal turbinate hypertrophy is among the most common nasal obstruction disorders, affecting the patient's quality of life significantly. Endoscopic submucosal diathermy is a prevalent cauterization procedure for treating turbinate hypertrophy. Regrettably, the nasal burn associated with diathermy typically heals slowly causing facial pain and nasal bleeding and possibly resulting in synechiae formation. In the current study, we have developed, for the first time, a polymeric film loaded with cholecalciferol for local treatment of nasal burns. The casting method was used to prepare films of different compositions of polymers such as chitosan, polyvinyl alcohol (PVA), Carbopol 971p (CP971p), and hydroxypropyl methylcellulose (HPMC) as well as a plasticizer. Several characterizations were performed for the cholecalciferol-loaded films (e.g. weight, thickness, content uniformity, surface pH, folding endurance, disintegration time, and in vitro release) to select the optimal formulation. The optimal formulation (F4) displayed compatibility between the used polymers and the drug. In vivo animal study was carried out to assess the healing efficacy of the formulated cholecalciferol-loaded film. The rabbits treated with the cholecalciferol-loaded film demonstrated significantly higher mRNA expression of the growth factor TGF-β and significantly lower mRNA expression of the proinflammatory cytokine TNF-α and IL-1β compared to the plain film treated group and the untreated control group. A randomized, single-blinded, parallel, controlled clinical trial was conducted on 20 patients scheduled to undergo endoscopic submucous diathermy. The results of the clinical study demonstrated significant reductions in facial pain and nasal bleeding scores for the nostrils treated with cholecalciferol-loaded films in comparison to the nostrils treated with plain films. Furthermore, the endoscopic examination showed good healing for 95% of the cholecalciferol-loaded film-treated nostrils. In conclusion, the optimized film can be considered an opportune approach for enhancing the healing rate of nasal burns and thus reducing the downsides of the diathermy procedure.

GL-FusionNet: Fusing global and local features to classify deep and superficial partial thickness burn

Burns constitute one of the most common injuries in the world, and they can be very painful for the patient. Especially in the judgment of superficial partial thickness burns and deep partial thickness burns, many inexperienced clinicians are easily confused. Therefore, in order to make burn depth classification automated as well as accurate, we have introduced the deep learning method. This methodology uses a U-Net to segment burn wounds. On this basis, a new thickness burn classification model that fuses global and local features (GL-FusionNet) is proposed. For the thickness burn classification model, we use a ResNet50 to extract local features, use a ResNet101 to extract global features, and finally implement the add method to perform feature fusion and obtain the deep partial or superficial partial thickness burn classification results. Burns images are collected clinically, and they are segmented and labeled by professional physicians. Among the segmentation methods, the U-Net used achieved a Dice score of 85.352 and IoU score of 83.916, which are the best results among all of the comparative experiments. In the classification model, different existing classification networks are mainly used, as well as a fusion strategy and feature extraction method that are adjusted to conduct experiments; the proposed fusion network model also achieved the best results. Our method yielded the following: accuracy of 93.523, recall of 93.67, precision of 93.51, and F1-score of 93.513. In addition, the proposed method can quickly complete the auxiliary diagnosis of the wound in the clinic, which can greatly improve the efficiency of the initial diagnosis of burns and the nursing care of clinical medical staff.

Burns: Classification, Pathophysiology, and Treatment: A Review

Burns and their treatment are a significant medical problem. The loss of the physical barrier function of the skin opens the door to microbial invasion and can lead to infection. The repair process of the damage caused by the burn is impaired due to the enhanced loss of fluids and minerals through the burn wound, the onset of hypermetabolism with the concomitant disruption of nutrient supply, and derangements in the endocrine system. In addition, the initiated inflammatory and free radical processes drive the progression of oxidative stress, the inhibition of which largely depends on an adequate supply of antioxidants and minerals. Clinical experience and research provide more and more data to make the treatment of patients with thermal injury increasingly effective. The publication discusses disorders occurring in patients after thermal injury and the methods used at various stages of treatment.

Triage of in vivo burn injuries and prediction of wound healing outcome using neural networks and modeling of the terahertz permittivity based on the double Debye dielectric parameters

The initial assessment of the depth of a burn injury during triage forms the basis for determination of the course of the clinical treatment plan. However, severe skin burns are highly dynamic and hard to predict. This results in a low accuracy rate of about 60 - 75% in the diagnosis of partial-thickness burns in the acute post-burn period. Terahertz time-domain spectroscopy (THz-TDS) has demonstrated a significant potential for non-invasive and timely estimation of the burn severity. Here, we describe a methodology for the measurement and numerical modeling of the dielectric permittivity of the in vivo porcine skin burns. We use the double Debye dielectric relaxation theory to model the permittivity of the burned tissue. We further investigate the origins of dielectric contrast between the burns of various severity, as determined histologically based on the percentage of the burned dermis, using the empirical Debye parameters. We demonstrate that the five parameters of the double Debye model can form an artificial neural network classification algorithm capable of automatic diagnosis of the severity of the burn injuries, and predicting its ultimate wound healing outcome by forecasting its re-epithelialization status in 28 days. Our results demonstrate that the Debye dielectric parameters provide a physics-based approach for the extraction of the biomedical diagnostic markers from the broadband THz pulses. This method can significantly boost dimensionality reduction of THz training data in artificial intelligence models and streamline machine learning algorithms.

Mapping the 3D remodeling of the extracellular matrix in human hypertrophic scar by multi-parametric multiphoton imaging using endogenous contrast

The hypertrophic scar is an aberrant form of wound healing process, whose clinical efficacy is limited by a lack of understanding of its pathophysiology. Remodeling of collagen and elastin fibers in the extracellular matrix (ECM) is closely associated with scar progression. Herein, we perform label-free multiphoton microscopy (MPM) of both fiber components from human skin specimens and propose a multi-fiber metrics (MFM) analysis model for mapping the structural remodeling of the ECM in hypertrophic scars in a highly-sensitive, three-dimensional (3D) manner. We find that both fiber components become wavier and more disorganized in scar tissues, while content accumulation is observed from elastin fibers only. The 3D MFM analysis can effectively distinguish normal and scar tissues with better than 95% in accuracy and 0.999 in the area under the curve value of the receiver operating characteristic curve. Further, unique organizational features with orderly alignment of both fibers are observed in scar-normal adjacent regions, and an optimized combination of features from 3D MFM analysis enables successful identification of all the boundaries. This imaging and analysis system uncovers the 3D architecture of the ECM in hypertrophic scars and exhibits great translational potential for evaluating scars in vivo and identifying individualized treatment targets.

The Role of Local Inflammation and Hypoxia in the Formation of Hypertrophic Scars-A New Model in the Duroc Pig

Hypertrophic scars continue to be a major burden, especially after burns. Persistent inflammation during wound healing appears to be the precipitating aspect in pathologic scarring. The lack of a standardized model hinders research from fully elucidating pathophysiology and therapy, as most therapeutic approaches have sparse evidence. The goal of this project was to investigate the mechanisms of scar formation after prolonged wound inflammation and to introduce a method for generating standardized hypertrophic scars by inducing prolonged inflammation. Four wound types were created in Duroc pigs: full-thickness wounds, burn wounds, and both of them with induced hyperinflammation by resiquimod. Clinical assessment (Vancouver Scar Scale), tissue oxygenation by hyperspectral imaging, histologic assessment, and gene expression analysis were performed at various time points during the following five months. Native burn wounds as well as resiquimod-induced full-thickness and burn wounds resulted in more hypertrophic scars than full-thickness wounds. The scar scale showed significantly higher scores in burn- and resiquimod-induced wounds compared with full-thickness wounds as of day 77. These three wound types also showed relative hypoxia compared with uninduced full-thickness wounds in hyperspectral imaging and increased expression of HIF1a levels. The highest number of inflammatory cells was detected in resiquimod-induced full-thickness wounds with histologic features of hypertrophic scars in burn and resiquimod-induced wounds. Gene expression analysis revealed increased inflammation with only moderately altered fibrosis markers. We successfully created hypertrophic scars in the Duroc pig by using different wound etiologies. Inflammation caused by burns or resiquimod induction led to scars similar to human hypertrophic scars. This model may allow for the further investigation of the exact mechanisms of pathological scars, the role of hypoxia and inflammation, and the testing of therapeutic approaches.

Risk Models to Predict Mortality in Burn Patients: A Systematic Review and Meta-analysis

The predictive capability of various risk assessment models (RAMs) in evaluating the risk of mortality in burn patients is not well established. It is also unclear which RAM provides the highest discriminative ability and presents the highest clinical utility. We pooled all available studies to establish this validity and compare the predictive capability of the various RAMs.

Methods

We reviewed PubMed, MEDLINE, and Embase from their inception up until December 2021 for studies evaluating risk of mortality in burn patients as stratified by RAMs. Data were pooled using random-effect models and presented as area under the receiver operating characteristic (AUROC) curve.

Results

Thirty-four studies, comprising of a total of 98,610 patients, were included in our analysis. Most studies were found to have a low risk of bias and a good measure of applicability. Nine RAMs were evaluated. We discovered that the classic Baux; the revised Baux; and the Fatality by Longevity, APACHE II score, Measured Extent of burn, and Sex (FLAMES) scores presented with the highest discriminative power with there being no significant difference between the results presented by them [AUROCs (95% CI), 0.92 (0.90-0.95), 0.92 (0.90-0.93), 0.94 (0.91-0.97), respectively, with P < 0.00001 for all].

Conclusions

Many RAMs exist with no consensus on the optimal model to utilize and assess risk of mortality for burn patients. This study is the first systematic review and meta-analysis to compare the current RAMs' discriminative ability to predict mortality in patients with burn injuries. This meta-analysis demonstrated that RAMs designed for assessing mortality in individuals with burns have acceptable to great discriminative capacity, with the classic Baux, revised Baux, and FLAMES demonstrating superior discriminative performance in predicting death. FLAMES exhibited the highest discriminative ability among the RAMs studied.

Accurate and early prediction of the wound healing outcome of burn injuries using the wavelet Shannon entropy of terahertz time-domain waveforms

Significance

Severe burn injuries cause significant hypermetabolic alterations that are highly dynamic, hard to predict, and require acute and critical care. The clinical assessments of the severity of burn injuries are highly subjective and have consistently been reported to be inaccurate. Therefore, the utilization of other imaging modalities is crucial to reaching an objective and accurate burn assessment modality.

Aim

We describe a non-invasive technique using terahertz time-domain spectroscopy (THz-TDS) and the wavelet packet Shannon entropy to automatically estimate the burn depth and predict the wound healing outcome of thermal burn injuries.

Approach

We created 40 burn injuries of different severity grades in two porcine models using scald and contact methods of infliction. We used our THz portable handheld spectral reflection (PHASR) scanner to obtain the in vivo THz-TDS images. We used the energy to Shannon entropy ratio of the wavelet packet coefficients of the THz-TDS waveforms on day 0 to create supervised support vector machine (SVM) classification models. Histological assessments of the burn biopsies serve as the ground truth.

Results

We achieved an accuracy rate of 94.7% in predicting the wound healing outcome, as determined by histological measurement of the re-epithelialization rate on day 28 post-burn induction, using the THz-TDS measurements obtained on day 0. Furthermore, we report the accuracy rates of 89%, 87.1%, and 87.6% in automatic diagnosis of the superficial partial-thickness, deep partial-thickness, and full-thickness burns, respectively, using a multiclass SVM model.

Conclusions

The THz PHASR scanner promises a robust, high-speed, and accurate diagnostic modality to improve the clinical triage of burns and their management.

Lighting the Way for Necrosis Excision Through Indocyanine Green Fluorescence-Guided Surgery

BACKGROUND

No objective technique exists to distinguish necrotic from viable tissue, risking over-excision in burns and loss of wound healing potential. Second window indocyanine green (SWIG) is a novel fluorescence-imaging modality being studied to identify residual solid tumors during oncological surgery. SWIG has also been shown to have avidity for necrosis in animal models, but translation of these findings to humans is lacking. The objective of this study was to evaluate SWIG in the identification of burn wound necrosis and compare it with previously published indocyanine green angiography (ICGA) techniques.

STUDY DESIGN

This study used mouse, human skin xenograft and human patient burn models. Brightfield and SWIG near-infrared imaging were performed on macroscopic tissue samples, which were then cryopreserved, sectioned, and analyzed for microscopic fluorescence. SWIG fluorescence findings were correlated to visual assessment of the burn wound as well as histological markers of necrosis using hematoxylin and eosin and lactate dehydrogenase stains.

RESULTS

We found that SWIG identified burn necrosis in a manner dependent on the dose and timing of indocyanine green (ICG) administration and had an inverse fluorescence signal compared with ICGA. Furthermore, SWIG fluorescence identified the interface of viable and nonviable tissue.

CONCLUSION

Our study confirmed that ICGA is an inconsistent and nonstandardized modality to evaluate burn injuries. In contrast, SWIG imaging is a potential imaging modality to objectively prognosticate burn wound healing potential and guide intraoperative burn excision. Further studies are needed to define ratios of fluorescence intensity values to guide surgical decision-making in burn excision and to better define how ICG is retained in necrotic tissue to enhance utility of SWIG in other disease processes.

Burn characterization using object-oriented hyperspectral image classification

This paper presents a new approach based on hyperspectral imaging combined with an object-oriented classification method that allows the generation of burn depth classification maps facilitating easier characterization of burns. Hyperspectral images of 14 patients diagnosed with burns on the upper and lower limbs were acquired using a pushbroom hyperspectral imaging system. The images were analyzed using an object-oriented classification approach that uses objects with specific spectral, textural and spatial attributes as the minimum unit for classifying information. The method performance was evaluated in terms of overall accuracy, sensitivity, precision and specificity computed from the confusion matrix. The results revealed that the approach proposed in this study performed well in differentiating burn classes with a high level of overall accuracy (95.99% ± 0.60%), precision (97.30% ± 2.46%), sensitivity (97.23% ± 3.02%) and specificity (98.02% ± 1.98%). In conclusion, the object-based approach for burns hyperspectral images classification can provide maps that can help surgeons identify with better precision different depths of burn wounds.

A Spiking Neural Network Based on Retinal Ganglion Cells for Automatic Burn Image Segmentation

Burn is a common traumatic disease. After severe burn injury, the human body will increase catabolism, and burn wounds lead to a large amount of body fluid loss, with a high mortality rate. Therefore, in the early treatment for burn patients, it is essential to calculate the patient's water requirement based on the percentage of the burn wound area in the total body surface area (TBSA%). However, burn wounds are so complex that there is observer variability by the clinicians, making it challenging to locate the burn wounds accurately. Therefore, an objective, accurate location method of burn wounds is very necessary and meaningful. Convolutional neural networks (CNNs) provide feasible means for this requirement. However, although the CNNs continue to improve the accuracy in the semantic segmentation task, they are often limited by the computing resources of edge hardware. For this purpose, a lightweight burn wounds segmentation model is required. In our work, we constructed a burn image dataset and proposed a U-type spiking neural networks (SNNs) based on retinal ganglion cells (RGC) for segmenting burn and non-burn areas. Moreover, a module with cross-layer skip concatenation structure was introduced. Experimental results showed that the pixel accuracy of the proposed reached 92.89%, and our network parameter only needed 16.6 Mbytes. The results showed our model achieved remarkable accuracy while achieving edge hardware affinity.

Chitosan degradation products promote healing of burn wounds of rat skin

Burns can impair the barrier function of the skin, and small burns can also cause high mortality. The WHO has described that over 180,000 people die of burns worldwide each year. Thus, the treatment of burn wounds is a major clinical challenge. Chitooligosaccharides (COS) are alkaline amino oligosaccharides with small molecular weights obtained by enzyme or chemical degradation of chitosan. With the characteristics of biocompatibility, water solubility and degradability, it has attracted increasing attention in the fields of biomedicine. In the present study, we used COS to treat deep second-degree burn wounds of rat skin and found that COS was able to promote wound healing. We also revealed that COS could promote fibroblast proliferation. Transcriptome sequencing analysis was performed on COS-treated fibroblasts to identify the underlying mechanisms. The results showed that COS was able to promote wound healing through regulation of the mitogen-activated protein kinase (MAPK) pathway and growth factor Hepatocyte Growth Factor (HGF). Our results provide a potential drug for burn wound therapy and the related molecular mechanism.

Evaluation of Bromelain-Based Enzymatic Debridement Combined with Laser Doppler Imaging and Healing of Burn Wounds

Background

Accurate estimation of burn depth is crucial for correct treatment decision making. Bromelain-based enzymatic debridement (ED) may improve clinical assessment of burn depth. Laser Doppler imaging (LDI) provides a valuable indicator of burn depth by analyzing microcirculation within tissue beds. This study aimed to evaluate bromelain-based enzymatic debridement combined with laser Doppler imaging and healing of 42 wounds in 19 patients with mixed second- and third-degree thermal burns.

Material/Methods

We included 42 wounds in 19 patients with mixed deep dermal and full-thickness thermal burns. All patients were treated with eschar-specific removal agent for ED. The perfusion of each wound after ED was assessed using LDI. Healing time was estimated by 2 experienced burn surgeons and marked by the observation of epithelization. The usefulness of the LDI performed after ED in predicting healing time was estimated. The findings were analyzed to determine a cut-off value for LDI that indicates if a burn will heal spontaneously.

Results

We observed that burn wounds with higher mean perfusion healed faster. The analysis showed a strong relationship between perfusion after ED and healing time (Spearman rank correlation coefficient=−0.803). A mean perfusion greater than 296.89 indicated that the wound could heal spontaneously and does not require skin grafting.

Conclusions

LDI examination of an already debrided wound allows for a reliable assessment of perfusion at an early stage of treatment. The use of a safe and effective debridement method in conjunction with a non-invasive diagnostic tool could improve burn management.

Burn depth assessment using hyperspectral imaging in a prospective single center study

BACKGROUND

The assessment of thermal burn depth remains challenging. Over the last decades, several optical systems were developed to determine burn depth. So far, only laser doppler imaging (LDI) has been shown to be reliable while others such as infrared thermography or spectrophotometric intracutaneous analysis have been less accurate. The aim of our study is to evaluate hyperspectral imaging (HSI) as a new optical device.

METHODS

Patients suffering thermal trauma treated in a burn unit in Germany between November 2019 and September 2020 were included. Inclusion criteria were age ≥18 years, 2^nd or 3^rd degree thermal burns, written informed consent and presentation within 24 h after injury. Clinical assessment and hyperspectral imaging were performed 24, 48 and 72 h after the injury. Patients in whom secondary wound closure was complete within 21 days (group A) were compared to patients in whom secondary wound closure took more than 21 days or where skin grafting was indicated (group B). Demographic data and the primary parameters generated by HSI were documented. A Mann Whitney-U test was performed to compare the groups. A p-value below 0.05 was considered to be statistically significant. The data generated using HSI were combined to create the HSI burn index (BI). Using a logistic regression and receiver operating characteristics curve (ROC) sensitivity and specificity of the BI were calculated. The trial was officially registered on DRKS (registration number: DRKS00022843).

RESULTS

Overall, 59 patients with burn wounds were eligible for inclusion. Ten patients were excluded because of a poor data quality. Group A comprised 36 patients with a mean age of 41.5 years and a mean burnt body surface area of 2.7%. In comparison, 13 patients were allocated to group B because of the need for a skin graft (n = 10) or protracted secondary wound closure lasting more than 21 days. The mean age of these patients was 46.8 years. They had a mean affected body surface area of 4.0%. 24, 48, and 72 h after trauma the BI was 1.0 ± 0.28, 1.2 ± 0.29 and 1.55 ± 0.27 in group A and 0.78 ± 0.14, 1.05 ± 0.23 and 1.23 ± 0.27 in group B. At every time point significant differences were demonstrated between the groups. At 24 h, ROC analysis demonstrated BI threshold of 0.95 (sensitivity 0.61/specificity 1.0), on the second day of 1.17 (sensitivity 0.51/specificity 0.81) and on the third day of 1.27 (sensitivity 0.92/specificity 0.71).

CONCLUSION

Changes in microcirculation within the first 72 h after thermal trauma were reflected by an increasing BI in both groups. After 72 h, the BI is able to predict the need for a skin graft with a sensitivity of 92% and a specificity of 71%.

Management of Pediatric Facial Burns with Zinc-Hyaluronan Gel

Zinc-hyaluronan-containing burn dressings have been associated with enhanced reepithelialization and low infection rates, although their effectiveness has not yet been investigated in pediatric facial thermal injuries. This single-arm, retrospective cohort study assessed the characteristics of 23 children (≤17-year-old) with facial superficial partial-thickness burns and the wound closure capabilities of the applied zinc-hyaluronan gel. Patients were admitted consecutively to the Pediatric Surgery Division in Pécs, Hungary, between 1 January 2016 and 15 October 2021. The mean age of the children was 6.2 years; 30.4% of them were younger than 1 year. An average of 3% total body surface was injured in the facial region and 47.8% of the patients had other areas damaged as well, most frequently the left upper limb (30.4%). The mean time until complete reepithelialization was 7.9 days and the children spent 2 days in the hospital. Wound cultures revealed normal bacterial growth in all cases and follow-up examinations found no hypertrophic scarring. In conclusion, pediatric facial superficial partial-thickness burns are prevalent during infancy and coincide with left upper limb injuries. Rapid wound closure and low complication rates are accountable for the moderate amount of hospitalization. These benefits, along with the gel’s ease of applicability and spontaneous separation, are linked to child-friendly burn care.

Globularia arabica methanolic leaf extract has higher efficacy on burn wound healing in diabetic rats compared to Malva slyvestries methanolic leaf extract

This study aimed to see how effective Globulari. arabica and Malva. slyvestries-based cream formulations were at healing scald burn wounds in rats. Depending on ointment preparations of 1%, 5%, and 10% w/w were created. For comparison, an ointment base and a regular burn cream composed soframycine were utilized. Rats introduced a burn by solidifying equipment at 100°C on a 14 mm 2 shaved dorsal region. A deep second-degree burn was created, and the percentage of wound contraction was measured over the next 15 days. The rats were euthanized on days 8 and 15, and histological slides were prepared using hematoxylin and eosin staining. Compared to the control group, a substantial increase in wound contraction and a significant decrease in the duration of epithelialization in the based ointment-treated groups. However, as paralleled to Globularia arabica, significant (P < 0.05) results were observed with 10% Globularia. arabica cream, whereas Malva. slyverstries indicate minimal healing. Soframycine causes a substantial increase in wound contraction (P <0.05). Soframycine cream with 10% Globularia arabica therapy resulted in practically complete re-epithelialization and re-structuring of wound tissue on histological examination, whereas Malva slyversries treatment resulted in low epithelization during treatment days. The findings suggest that Globularia arabica-based cream has the wound-healing capability.

Pain management during a bromelain-based selective enzymatic debridement in paediatric and adult burn patients

BACKGROUND

Pain associated with surgical or enzymatic burn wound debridement prevents many burn centres from working outside an operating theatre, creating a burden. Alternatives for general anaesthesia to manage pain in burn patients treated with enzymatic debridements, such as regional anaesthesia, have not been studied in detail. This study explores the different possibilities for pain management during a bedside NexoBrid™ procedure.

MATERIAL AND METHODS

We performed a single-centre retrospective study that included 82 paediatric, adolescent, and adult patients with deep dermal and full-thickness burns treated bedside with NexoBrid™ under regional or general anaesthesia. Outcome measures were pain during the NexoBrid™ procedure, the safety of the anaesthesia and the NexoBrid™ procedure, logistics of the bedside NexoBrid™ procedure, and time to wound closure.

RESULTS

Forty-three patients in the adult group (43/67, 64%) only presented with burn wounds on one upper or the one or two lower extremities. In 29 of them (29/43, 67%), a NexoBrid™ procedure was performed under regional anaesthesia, which resulted in low pain levels without any adverse events. All seven patients in the paediatric group, where only one upper or one or two lower limbs were involved (7/15, 47%), underwent a NexoBrid™ procedure performed under regional anaesthesia where no adverse events were reported. In these children, the use of regional anaesthesia was associated with a significant decrease in time to wound closure (average treatment effect on the treated = -22.5 days, p = 0.021).

CONCLUSION

This study highlights that regional anaesthesia administered at the bedside should be the method of choice for pain management during NexoBrid™ procedures because often, it can be adequately and safely performed in all age groups. This approach will reduce the burden on operating theatres. A flow chart has been developed to guide pain management during a NexoBrid™ procedure.

Evaluation of hyperspectral imaging as a modern aid in clinical assessment of burn wounds of the upper extremity

The most common burn wound assessment continues to be the clinical inspection and the tactile examination, which are subjective and remain challenging even for experienced burn surgeons. Recently, hyperspectral imaging camera systems have been increasingly used to support the evaluation of burn wounds. The aim of our study was to determine if hyperspectral imaging analysis differentiates and objectifies the assessment of burn wounds in burns of the upper extremities. We included 97 superficial partial, deep partial dermal burns, and full thickness burns. Hyperspectral imaging analysis was performed for all burns using proprietary software. The software recorded parameters for tissue oxygenation (StO2), tissue hemoglobin index, and near-infrared perfusion. These values were compared with the recordings for healthy, non-burned skin. We found that hyperspectral imaging analysis effectively differentiates burn wounds and shows the ability to distinguish even superficial partial burns from deep partial burns in the near-infrared perfusion analysis feature. Although, it was not possible to differentiate burn wounds in all features. Currently, it is important to optimize the respective reference values of the individual burn degrees for an objectified assessment.

Performance of BEAMS risk of death score for mortality prediction in Australian and New Zealand burns patients

The BEAMS (Burns Evaluation And Mortality Study) risk of death score was developed in 2013 as a mortality prediction tool for burns patients admitted to an ICU (Intensive Care Unit) in Australia and New Zealand. While it previously performed well, identifying high risk groups and allowing benchmarking, over time such scores may lose calibration or be superseded by improved scoring systems. Our aim was to assess the performance of the BEAMS score in a modern cohort of burns patient. Data was sourced from the Burns Registry of Australia and New Zealand (BRANZ) and the Australia New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation (ANZICS CORE) databases. Data was linked using probabilistic methodology. BEAMS risk of death scores was calculated for all adult patients. Between 2009 and 2019, there were 2075 patients admitted to an Australian or New Zealand ICU with a burns related injury. Advanced age, female gender, higher %TBSA burns and inhalation injury were all associated with increased rate of mortality (p<0.05). Overall hospital mortality was 9.4% (n=195). The predicted risk of death from BEAMS was 8.7% and the score had an area under the receiver operating characteristic curve of 0.934. We found the BEAMS Risk of Death score continues to have excellent performance in a modern cohort of adult critically ill burns patients. It remains a valid tool for mortality prediction among adult burns patients admitted to ICU across Australia and New Zealand.

Deep neural network classification of in vivo burn injuries with different etiologies using terahertz time-domain spectral imaging

Thermal injuries can occur due to direct exposure to hot objects or liquids, flames, electricity, solar energy and several other sources. If the resulting injury is a deep partial thickness burn, the accuracy of a physician's clinical assessment is as low as 50-76% in determining the healing outcome. In this study, we show that the Terahertz Portable Handheld Spectral Reflection (THz-PHASR) Scanner combined with a deep neural network classification algorithm can accurately differentiate between partial-, deep partial-, and full-thickness burns 1-hour post injury, regardless of the etiology, scanner geometry, or THz spectroscopy sampling method (ROC-AUC = 91%, 88%, and 86%, respectively). The neural network diagnostic method simplifies the classification process by directly using the pre-processed THz spectra and removing the need for any hyperspectral feature extraction. Our results show that deep learning methods based on THz time-domain spectroscopy (THz-TDS) measurements can be used to guide clinical treatment plans based on objective and accurate classification of burn injuries.

Supervised machine learning for automatic classification of in vivo scald and contact burn injuries using the terahertz Portable Handheld Spectral Reflection (PHASR) Scanner

We present an automatic classification strategy for early and accurate assessment of burn injuries using terahertz (THz) time-domain spectroscopic imaging. Burn injuries of different severity grades, representing superficial partial-thickness (SPT), deep partial-thickness (DPT), and full-thickness (FT) wounds, were created by a standardized porcine scald model. THz spectroscopic imaging was performed using our new fiber-coupled Portable HAndheld Spectral Reflection Scanner, incorporating a telecentric beam steering configuration and an f-[Formula: see text] scanning lens. ASynchronous Optical Sampling in a dual-fiber-laser THz spectrometer with 100 MHz repetition rate enabled high-speed spectroscopic measurements. Given twenty-four different samples composed of ten scald and ten contact burns and four healthy samples, supervised machine learning algorithms using THz-TDS spectra achieved areas under the receiver operating characteristic curves of 0.88, 0.93, and 0.93 when differentiating between SPT, DPT, and FT burns, respectively, as determined by independent histological assessments. These results show the potential utility of our new broadband THz PHASR Scanner for early and accurate triage of burn injuries.

The degree of joint range of motion limitations after burn injuries during recovery

INTRODUCTION

The aim of this study was to determine the degree of ROM limitations of extremities, joints and planes of motion after burns and its prevalence over time.

METHOD

The database of a longitudinal multicenter cohort study in the Netherlands (2011-2012) was used. From patients with acute burns involving the neck, shoulder, elbow, wrist, hip, knee and ankle joints that had surgery, ROM of 17 planes of motion was assessed by goniometry at 3, 6 weeks, 3-6-9 and 12 months after burns and at discharge.

RESULTS

At 12 months after injury, 12 out of 17 planes of motion demonstrated persistent joint limitations. The five unlimited planes of motion were all of the lower extremity. The most severely limited joints at 12 months were the neck, ankle, wrist and shoulder. The lower extremity was more severely limited in the early phase of recovery whereas at 12 months the upper extremity was more severely limited.

CONCLUSION

The degree of ROM limitations and prevalence varied over time between extremities, joints and planes of motion. This study showed which joints and planes of motion should be watched specifically concerning the development of scar contracture.

Validity of laser speckle contrast imaging for the prediction of burn wound healing potential

OBJECTIVE

To assess validity of Laser Speckle Contrast Imaging (LSCI) for the measurement of burn wound healing potential (HP) in a burn centre patient population, based on Laser Doppler Imaging (LDI) as reference standard.

METHOD

A single-centre prospective observational cohort study was performed between September-December 2019. A total of 50 burns in 14 patients were included. Imaging and data collection were standardized. Correlation between LSCI and LDI flux values was tested. ROC curves were developed to test the discriminative ability of LSCI between LDI HP categories.

RESULTS

Number of adults and children were equal. Mean total body surface area burnt was 5.5%. Main burn causes were scalds (64%) and flame burns (36%). LSCI set-up and imaging duration was 3 min and 10 s, respectively. LSCI was able to discriminate between wounds with early versus delayed HP (<14 versus ≥14 days) with sensitivity 71% and specificity 95% (p < 0.001). For HP ≤21 versus >21 days, similar sensitivity (74%) and specificity (95%) were found (p < 0.001). Correlations between LSCI and LDI flux values were moderate (<14 days) to absent (>21 days).

CONCLUSION

LSCI shows good validity for the prediction of burn wound HP. It is a highly feasible, patient and physician friendly tool.

The In Vivo Quantitative Assessment of the Effectiveness of Low-Dose Photodynamic Therapy on Wound Healing Using Optical Coherence Tomography

The effect of low-dose photodynamic therapy on in vivo wound healing was investigated using optical coherence tomography. This work aims to develop an approach to quantitative assessment of the wound's state during wound healing including the effect of low-dose photodynamic therapy using topical application of two different photosensitizers, 5-aminolevulinic acid and methylene blue, and two laser doses of 1 J/cm2 and 4 J/cm2. It was concluded that the laser dose of 4 J/cm2 was better compared to 1 J/cm2 and allowed the wound healing process to accelerate.

At The Forefront of Penile Surgical Reconstruction: A Bibliometric Study of the 100 Most-Cited Articles

PURPOSE

The citation count of a scientific article is considered as the recognition it received from this field. The purpose of this bibliometric analysis was to identify the top 100 most-cited scientific articles in penile surgical reconstruction.

METHODS

The Web of Science database was used to extract the top 100 most-cited articles. Individual articles were reviewed to identify the authorship, published journal, journal impact factor (IF), primary disease, article type, institution and country of origin, and year of publication.

RESULTS

The top 100 most-cited articles were published between 1947 and 2013. The number of citations ranged from 23 to 233. Journal of Urology contributed the most articles (n = 36). Articles with a high level of evidence like prospective analysis (n = 5), systematic review and meta-analysis (n = 2), and guideline (n = 1) were all published after 2000. The average citation per year of articles published in high-IF journals was significantly higher than that of other articles (p = 0.0129). There was a positive linear correlation between citation count per year and publication year (r² = 0.26, p < 0.001). Among the top 100 articles, 74 articles were interlinked via citation of each other. The major topic of co-citation network was the application of flaps in penile reconstruction.

CONCLUSIONS

The analysis of top 100 most-cited articles facilitates the comprehensive recognition of current focus in the field of penile surgical reconstruction, which is the exploration of flaps and development of new techniques in penile reconstruction. In the future, more attention should be paid to evidence-based medicine to provide high-level evidence for research.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Machine learning analysis of multispectral imaging and clinical risk factors to predict amputation wound healing

OBJECTIVE

Prediction of amputation wound healing is challenging due to the multifactorial nature of critical limb ischemia and lack of objective assessment tools. Up to one-third of amputations require revision to a more proximal level within 1 year. We tested a novel wound imaging system to predict amputation wound healing at initial evaluation.

METHODS

Patients planned to undergo amputation due to critical limb ischemia were prospectively enrolled. Clinicians evaluated the patients in traditional fashion, and all clinical decisions for amputation level were determined by the clinician's judgement. Multispectral images of the lower extremity were obtained preoperatively using a novel wound imaging system. Clinicians were blinded to the machine analysis. A standardized wound healing assessment was performed on postoperative day 30 by physical exam to determine whether the amputation site achieved complete healing. If operative revision or higher level of amputation was required, this was undertaken based solely upon the provider's clinical judgement. A machine learning algorithm combining the multispectral imaging data with patient clinical risk factors was trained and tested using cross-validation to measure the wound imaging system's accuracy of predicting amputation wound healing.

RESULTS

A total of 22 patients undergoing 25 amputations (10 toe, five transmetatarsal, eight below-knee, and two above-knee amputations) were enrolled. Eleven amputations (44%) were non-healing after 30 days. The machine learning algorithm had 91% sensitivity and 86% specificity for prediction of non-healing amputation sites (area under curve, 0.89).

CONCLUSIONS

This pilot study suggests that a machine learning algorithm combining multispectral wound imaging with patient clinical risk factors may improve prediction of amputation wound healing and therefore decrease the need for reoperation and incidence of delayed healing. We propose that this, in turn, may offer significant cost savings to the patient and health system in addition to decreasing length of stay for patients.

Effect of Rhus coriaria L. methanolic fruit extract on wound healing in diabetic and non-diabetic rats

AIM

This study assessed the effects of topical application of R. coriaria extract on the rate of wound closure. The rate of wound contraction was used to assess the wound healing efficacy of the R. coriaria fruit methanolic extract.

METHODS

Using excision and burn model of wound repair in diabetic male Wistar rats. Also, hydroxyproline, collagen content, and proinflammatory and anti-inflammatory cytokines levels were determined in this study.

RESULTS

During the early wound healing phase, interleukin 6 (IL-6) levels were found to be decreased by R. coriaria treatment and increased the level of interleukin 10 (IL-10). Increased wound contraction augmented with hydroxyproline and collagen content, supporting the early wound healing exhibited by R. coriaria. The epithelialization, neovascularization and enhanced hydroxyproline and collagen expression were strongly associated with the healing pattern.

CONCLUSION

This study indicating that R. coriaria methanolic fruit extract has a potent wound healing capacity. And may be effective in the topical therapy of wound healing.

Educational Case: Burn Injury-Pathophysiology, Classification, and Treatment

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Deep Learning-Assisted Burn Wound Diagnosis: Diagnostic Model Development Study

BACKGROUND

Accurate assessment of the percentage total body surface area (%TBSA) of burn wounds is crucial in the management of burn patients. The resuscitation fluid and nutritional needs of burn patients, their need for intensive unit care, and probability of mortality are all directly related to %TBSA. It is difficult to estimate a burn area of irregular shape by inspection. Many articles have reported discrepancies in estimating %TBSA by different doctors.

OBJECTIVE

We propose a method, based on deep learning, for burn wound detection, segmentation, and calculation of %TBSA on a pixel-to-pixel basis.

METHODS

A 2-step procedure was used to convert burn wound diagnosis into %TBSA. In the first step, images of burn wounds were collected from medical records and labeled by burn surgeons, and the data set was then input into 2 deep learning architectures, U-Net and Mask R-CNN, each configured with 2 different backbones, to segment the burn wounds. In the second step, we collected and labeled images of hands to create another data set, which was also input into U-Net and Mask R-CNN to segment the hands. The %TBSA of burn wounds was then calculated by comparing the pixels of mask areas on images of the burn wound and hand of the same patient according to the rule of hand, which states that one's hand accounts for 0.8% of TBSA.

RESULTS

A total of 2591 images of burn wounds were collected and labeled to form the burn wound data set. The data set was randomly split into training, validation, and testing sets in a ratio of 8:1:1. Four hundred images of volar hands were collected and labeled to form the hand data set, which was also split into 3 sets using the same method. For the images of burn wounds, Mask R-CNN with ResNet101 had the best segmentation result with a Dice coefficient (DC) of 0.9496, while U-Net with ResNet101 had a DC of 0.8545. For the hand images, U-Net and Mask R-CNN had similar performance with DC values of 0.9920 and 0.9910, respectively. Lastly, we conducted a test diagnosis in a burn patient. Mask R-CNN with ResNet101 had on average less deviation (0.115% TBSA) from the ground truth than burn surgeons.

CONCLUSIONS

This is one of the first studies to diagnose all depths of burn wounds and convert the segmentation results into %TBSA using different deep learning models. We aimed to assist medical staff in estimating burn size more accurately, thereby helping to provide precise care to burn victims.

The process to obtain reimbursement for enzymatic debridement in clinically deep burns

INTRODUCTION

Burn eschar removal by enzymatic debridement with NexoBrid^® (EDNX) results in a maximum preservation of all viable tissue, which is the main advantage over traditional tangential excision. The authors participated in a marketing authorization holder process to obtain reimbursement from the national health authorities in Belgium.

MATERIAL AND METHODS

The reimbursement process consisted of three phases, as specified by the reimbursement regulations required by the Belgian National Institute for Health and Disability Insurance (NIHDI).

RESULTS

Forty-one patients with clinically deep 2nd and 3rd degree burns, treated with EDNX in two Belgian burn centers, were included in the registry for the first phase of the reimbursement process. The total success rate of the EDNX treatment was 95.1% (39/41). Over half of the burn wounds treated with NexoBrid^® (55.2%) did not require any additional surgical debridement or skin grafting. To obtain definitive reimbursement, an extra 16 patients were included. In this population, 51.4% did not require any surgical intervention. The total success rate of the EDNX debridement in this group was 100%. Based on an estimated market share of 12% and around 75 patients in the third year after final reimbursement, a market access consultant calculated that NexoBrid^® will realize yearly savings for the Belgian Healthcare budget of at least €30.000.

CONCLUSION

Based on the results of this Belgian registry study in combination with the yearly healthcare budget savings, the NIHDI granted a final reimbursement for EDNX treatment in adults, endorsed by the Minister of Health on November 5^th, 2019.

A deep learning model for burn depth classification using ultrasound imaging

Identification of burn depth with sufficient accuracy is a challenging problem. This paper presents a deep convolutional neural network to classify burn depth based on altered tissue morphology of burned skin manifested as texture patterns in the ultrasound images. The network first learns a low-dimensional manifold of the unburned skin images using an encoder-decoder architecture that reconstructs it from ultrasound images of burned skin. The encoder is then re-trained to classify burn depths. The encoder-decoder network is trained using a dataset comprised of B-mode ultrasound images of unburned and burned ex vivo porcine skin samples. The classifier is developed using B-mode images of burned in situ skin samples obtained from freshly euthanized postmortem pigs. The performance metrics obtained from 20-fold cross-validation show that the model can identify deep-partial thickness burns, which is the most difficult to diagnose clinically, with 99% accuracy, 98% sensitivity, and 100% specificity. The diagnostic accuracy of the classifier is further illustrated by the high area under the curve values of 0.99 and 0.95, respectively, for the receiver operating characteristic and precision-recall curves. A post hoc explanation indicates that the classifier activates the discriminative textural features in the B-mode images for burn classification. The proposed model has the potential for clinical utility in assisting the clinical assessment of burn depths using a widely available clinical imaging device.

Potential for Machine Learning in Burn Care

INTRODUCTION

Burn-related injuries are a leading cause of morbidity across the globe. Accurate assessment and treatment have been demonstrated to reduce the morbidity and mortality. This essay explores the forms of artificial intelligence to be implemented the field of burns management to optimise the care we deliver in the National Health Service (NHS) in the UK.

METHODS

Machine Learning methods which predict or classify are explored. This includes linear and logistic regression, artificial neural networks, deep learning, and decision tree analysis.

DISCUSSION

Utilizing Machine Learning in burns care holds potential from prevention, burns assessment, predicting mortality and critical care monitoring to healing time. Establishing a regional or national Machine Learning group would be the first step towards the development of these essential technologies.

CONCLUSION

The implementation of machine learning technologies will require buy-in from the NHS health boards, with significant implications with cost of investment, implementation, employment of machine learning teams and provision of training to medical professionals.

Treatment of Partial Thickness Burns: A Prospective, Randomized Controlled Trial Comparing Four Routinely Used Burns Dressings in an Ambulatory Care Setting

This prospective, randomized controlled trial study compared the effects of four dressings for adult partial thickness burns, focusing on re-epithelialization time and cost effectiveness. Adults with partial thickness burns meeting inclusion criteria were randomized to either Biobrane™, Acticoat™, Mepilex® Ag, or Aquacel® Ag. Primary endpoint for analysis was >95% re-epithelialization. Incremental cost-effectiveness ratios were calculated based on dressing costs. Dominance probabilities between treatment arms were calculated from bootstrap resampling trial data. One hunderd thirty-one partial thickness burn wounds in 119 patients were randomized. Adjusting for sex, age, smoking status, burn mechanism, TBSA, and first aid adequacy, Mepilex® Ag had a reduced time to re-epithelialization compared to Biobrane™ (IRR: 1.26; 95% CI: 1.07-1.48, P < .01). Economic analysis showed that there was a 99%, 71%, and 53% probability that Mepilex® Ag dominated (cheaper and more effective) Biobrane™, Acticoat™, and Aquacel® Ag, respectively. Mepilex® Ag achieved faster re-epithelialization and better cost effectiveness. Patient satisfaction and comfort seems better with Biobrane™ although not reflected within the end outcome of the healed wound. It is the patients' (after extensive education) and clinicians' choice, level of experience, and availability of products in praxis that will guide the decision as to which the product is used individually on which patient.