Patient Weight and Chemoprophylaxis in Abdominoplasty: Does It Result in More Bleeding Events?

BACKGROUND: Bariatric surgery has gained popularity in recent decades as an effective treatment for obesity. Abdominoplasty is one of the most often performed aesthetic procedures all over the world. In post-bariatric patients undergoing abdominoplasty, the diameter size and number of the abdominal wall perforators increase proportionally with increased body weight. Postoperative complications that may occur are haematoma, and venous thromboembolism (VTE). In plastic surgery procedures VTE prophylaxis grades vary due to the lack of consensus and clear guidelines. The aim of this study was to explore the frequency of postoperative bleeding and VTE in patients undergoing abdominoplasty and to explore the risk factors associated with major bleeding. METHODS: A retrospective single-centre study of adult patients who were operated on by abdominoplasty between 2011 and 2020. Chemoprophylaxis including low molecular weight heparin (LMHW) was recommended when the operating time exceeded 2 h. RESULTS: A total of 102 patients were included. There were no patients with VTE. Eight patients were re-operated for major haematoma. The weight loss (peak weight to weight before the abdominoplasty) was 14.4 kg larger in the re-operation group (p = 0.03). Eighty-eight percent in the re-operation group and 67% in the other group were treated with LMWH (p = 0.43). Multivariable logistic regression showed that with each decrease from the peak in BMI kg/m2 the risk of re-operation for major haematoma was increased by 22% (p = 0.02). CONCLUSION: Abdominoplasty in patients after massive weight loss has a higher risk of postoperative bleeding. Having a clear protocol for chemoprophylaxis should be considered. 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 .

Perfusion Mapping of Flaps Using Indocyanine Green Fluorescence Angiography and Laser Speckle Contrast Imaging.

Background: Indocyanine green fluorescence angiography (ICG-FA) is often used for assessing tissue circulation in reconstructive surgery. Indocyanine green (ICG) is injected intravenously and visualized in the tissue with an infrared camera. The information is used to plan the surgery, for example, in free flap breast reconstructions. Laser speckle contrast imaging (LSCI) is another method that uses laser to assess tissue perfusion in the skin. Unlike ICG-FA, LSCI is noninvasive and may therefore have an advantaged compared with ICG-FA. The aim of this study was to evaluate the correlation between information obtained from these two techniques. Methods: Five deep inferior epigastric perforator patients were included. The flaps were assessed with LSCI and ICG-FA. For LSCI, the perfusion was calculated in 32 regions of interest. For ICG-FA, the maximum slope and area under curve (AUC) were calculated based on average pixel intensity data. Results: Large variations in maximum slope values could be seen between flaps, whereas AUC had lower variability within the same flap and between flaps. Pearson rank correlation comparing average perfusion (LSCI) and AUC (ICG-FA) showed a correlation between the values (r = 0.55, P < 0.0001). No significant correlation was observed between perfusion and maximum slope (r = 0.11, P = 0.18). Conclusions: There is a significant correlation between data obtained using LSCI and ICG-FA, when ICG-FA data are presented as AUC of the ICG-FA intensity curve. Maximum slope lacks significant correlation with flap data obtained with LSCI. The study indicates that LSCI may be used in reconstructive surgery to assess tissue circulation in a way similar to ICG-FA.

The impact and validity of the Berlin criteria on burn-induced ARDS: Examining mortality rates, and inhalation injury influences. A single center observational cohort study.

BACKGROUND: As several recent studies have shown low mortality rates in burn injury induced ARDS early (≤7 days) after the burn, the Berlin criteria for the ARDS diagnosis in this setting may be disputed. Related to this issue, the present study investigated the incidence, trajectory and risk factors of early Acute Respiratory Distress Syndrome (ARDS) and outcome in burn patients, as per the Berlin criteria, along with the concurrent prevalence and influence of inhalation injury, and ventilator-acquired pneumonia (VAP). METHODS: Over a 2.5-year period, burn patients with Total Burn Surface Area (TBSA) exceeding 10% admitted to a national burn center were included. The subgroup of interest comprised patients with more than 48 h of ventilatory support. This group was assessed for ARDS, inhalation injury, and VAP. RESULTS: Out of 292 admissions, 62 sustained burns > 10% TBSA. Of these, 28 (45%) underwent ventilatory support for over 48 h, almost all, 24 out of 28, meeting the criteria for ARDS early, within 7 days post-injury and with a PaO2/FiO2 (PF) ratio nadir at day 5. The mortality rate for this early ARDS group was under 10%, regardless of PF ratios (mean TBSA% 34,8%). Patients with concurrent inhalation injury and early ARDS showed significantly lower PF ratios (p < 0.001), and higher SOFA scores (p = 0.004) but without impact on mortality. Organ failure, indicated by SOFA scores, peaked early (day 3) and declined in the first week, mirroring PF ratio trends (p < 0.001). CONCLUSIONS: The low mortality associated with early ARDS in burn patients in this study challenges the Berlin criteria's for the early ARDS diagnosis, which for its validity relies on that higher mortality is linked to worsening PF ratios. The finding suggests alternative mechanisms, leading to the early ARDS diagnosis, such as the significant impact of inhalation injury on early PF ratios and organ failure, as seen in this study. The concurrence of early organ failure with declining PF ratios, supports, as expected, the hypothesis of trauma-induced inflammation/multi-organ failure mechanisms contributing to early ARDS. The study highlights the complexity in differentiating between the contributions of inhalation injury to early ARDS and the related organ dysfunction early in the burn care trajectory. The Berlin criteria for the ARDS diagnosis may not be fully applicable in the burn care setting, where the low mortality significantly deviates from that described in the original Berlin ARDS criteria publication but is as expected when considering the actual not very extensive burn injury sizes/Baux scores as in the present study.

MicroRNA-155 mediates multiple gene regulations pertinent to the role of human adipose-derived mesenchymal stem cells in skin regeneration.

Introduction: The role of Adipose-derived mesenchymal stem cells (AD-MSCs) in skin wound healing remains to be fully characterized. This study aims to evaluate the regenerative potential of autologous AD-MSCs in a non-healing porcine wound model, in addition to elucidate key miRNA-mediated epigenetic regulations that underlie the regenerative potential of AD-MSCs in wounds. Methods: The regenerative potential of autologous AD-MSCs was evaluated in porcine model using histopathology and spatial frequency domain imaging. Then, the correlations between miRNAs and proteins of AD-MSCs were evaluated using an integration analysis in primary human AD-MSCs in comparison to primary human keratinocytes. Transfection study of AD-MSCs was conducted to validate the bioinformatics data. Results: Autologous porcine AD-MSCs improved wound epithelialization and skin properties in comparison to control wounds. We identified 26 proteins upregulated in human AD-MSCs, including growth and angiogenic factors, chemokines and inflammatory cytokines. Pathway enrichment analysis highlighted cell signalling-associated pathways and immunomodulatory pathways. miRNA-target modelling revealed regulations related to genes encoding for 16 upregulated proteins. miR-155-5p was predicted to regulate Fibroblast growth factor 2 and 7, C-C motif chemokine ligand 2 and Vascular cell adhesion molecule 1. Transfecting human AD-MSCs cell line with anti-miR-155 showed transient gene silencing of the four proteins at 24 h post-transfection. Discussion: This study proposes a positive miR-155-mediated gene regulation of key factors involved in wound healing. The study represents a promising approach for miRNA-based and cell-free regenerative treatment for difficult-to-heal wounds. The therapeutic potential of miR-155 and its identified targets should be further explored in-vivo.

Wound infection among children with moderate burns - An explorative review of the association between reported frequency and diagnosis.

INTRODUCTION: The Linkoping burn centre in Sweden has, even though being a high income country, reported high burn wound infections (BWI) frequencies in scalded children compared to similar populations in other parts of the world. AIM: The aim was to investigate possible explanations for differences in frequency of BWI among children with partial thickness burns treated at the Linköping burn centre in Sweden, and that reported in other studies. METHOD: In order to investigate what BWI criteria that were used in similar studies a literature search on PubMed Central was done along with a retrospective analysis of children previously diagnosed as infected to confirm or reject the high infection frequency reported earlier. RESULT: Of the 34 selected publications reporting on BWI frequency 16 (47%) did not define a criteria for the BWI diagnosis and almost a third did not report on wound culturing. Of those who did report the use a third do not mention any bacterial growth found is these cultures. The retrospective analysis on children at the centre did not show any decrease in infection frequency even with some disagreement on onset for the BWI. CONCLUSION: The reporting of criteria and diagnosis of burn wound infection is highly variable making it difficult to interpret results and come to conclusions. The high frequency of BWI at the centre might be a result of close monitoring due to study participation, use of clean instead of sterile routine at dressing changes or low thresholds for the diagnosis in respect to changes in infection markers.

Exploring the similarities and differences of burn registers globally: Results from a data dictionary comparison study.

INTRODUCTION: Pooling and comparing data from the existing global network of burn registers represents a powerful, yet untapped, opportunity to improve burn prevention and care. There have been no studies investigating whether registers are sufficiently similar to allow data comparisons. It is also not known what differences exist that could bias analyses. Understanding this information is essential prior to any future data sharing. The aim of this project was to compare the variables collected in countrywide and intercountry burn registers to understand their similarities and differences. METHODS: Register custodians were invited to participate and share their data dictionaries. Inclusion and exclusion criteria were compared to understand each register population. Descriptive statistics were calculated for the number of unique variables. Variables were classified into themes. Definition, method, timing of measurement, and response options were compared for a sample of register concepts. RESULTS: 13 burn registries participated in the study. Inclusion criteria varied between registers. Median number of variables per register was 94 (range 28 - 890), of which 24% (range 4.8 - 100%) were required to be collected. Six themes (patient information, admission details, injury, inpatient, outpatient, other) and 41 subthemes were identified. Register concepts of age and timing of injury show similarities in data collection. Intent, mechanism, inhalational injury, infection, and patient death show greater variation in measurement. CONCLUSIONS: We found some commonalities between registers and some differences. Commonalities would assist in any future efforts to pool and compare data between registers. Differences between registers could introduce selection and measurement bias, which needs to be addressed in any strategy aiming to facilitate burn register data sharing. We recommend the development of common data elements used in an international minimum data set for burn injuries, including standard definitions and methods of measurement, as the next step in achieving burn register data sharing.

Long-term mortality after self-inflicted burns.

BACKGROUND: Those with self-inflicted burns are a small but consistent group among burn patients, with large injuries and conflicting findings regarding their in-hospital mortality. Overall, burn survivors have a shorter life expectancy, as compared with national controls, but long-term mortality after self-inflicted burns is understudied. The aim of this retrospective study was to investigate possible differences in long-term mortality among survivors after self-inflicted and accidental burns. METHODS: All adult patients with burns admitted at the Linköping Burn Centre and discharged alive between 2000 and 2017 were included, and end of follow up was April 26, 2021. Those with unknown survival status at that time were excluded. A Cox proportional hazards regression model, adjusted for age and sex, was used to analyse long term mortality. RESULTS: Among the 930 patients included in this study, 37 had self-inflicted burns. Overall, median follow up period was 8.8 years and crude mortality was 24.7%. After adjustment for age and sex, self-inflicted burns were independently associated with long-term mortality, Hazard Ratio= 2.08 (95% CI 1.13-3.83). Post hoc analysis showed that the effect was most pronounced during the first years after discharge although it was noticeable over the whole study period. CONCLUSION: Long-term risk of mortality after discharge from a burn centre was higher in patients with self-inflicted burns than in patients with accidental burns. The effect was noticeable over the whole study period although it was most pronounced during the first years after discharge.

Flap Survival after Reconstructive Surgery for Pressure Ulcers: A Cohort Study.

Background: Pressure ulcers are troublesome for patients and require considerable resources to resolve. Previous studies have focused on recurrence, whereas there are few studies on flap survival. The aim was to describe the group and to analyze possible factors for flap survival. Method: A descriptive retrospective analysis of all operations between 2008 and 2020 was carried out. Flap survival at 40 days was assessed. A flap was classified as a failure if a reoperation with removal or replacement was planned before, or in connection with, the first return visit. Variables of patient demographics, details of the pressure ulcers, and surgical treatment and care were analyzed with multivariable logistic regression for their effect on flap survival. Results: A total of 111 flaps were included [78 (70%) with random blood supply and 33 (30%) with axial or perforator-based blood supply]; 54 (49%) of the flaps were fasciocutaneous. Body mass index was 25 (IQR 22-28). Flap survival rate was 90%. Variables associated with flap failure were higher body mass index, congenital spinal cord injury, type of blood supply to the flap, and the use of methylene blue to guide debridement of the wound. Conclusions: The findings show factors that can be modified to improve future results, including a normalized body mass index and use of methylene blue in surgery to outline wound edges and depth, as this has been shown to protect against flap failure. Our data suggest that random flaps, such as V-Y, are preferable to axial flaps in the studied group.

Surviving Sepsis After Burn Campaign.

INTRODUCTION: The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes. METHODS: The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported. RESULTS: The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis. CONCLUSION: Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

miRNome and Proteome Profiling of Human Keratinocytes and Adipose Derived Stem Cells Proposed miRNA-Mediated Regulations of Epidermal Growth Factor and Interleukin 1-Alpha.

Wound healing is regulated by complex crosstalk between keratinocytes and other cell types, including stem cells. In this study, a 7-day direct co-culture model of human keratinocytes and adipose-derived stem cells (ADSCs) was proposed to study the interaction between the two cell types, in order to identify regulators of ADSCs differentiation toward the epidermal lineage. As major mediators of cell communication, miRNome and proteome profiles in cell lysates of cultured human keratinocytes and ADSCs were explored through experimental and computational analyses. GeneChip® miRNA microarray, identified 378 differentially expressed miRNAs; of these, 114 miRNAs were upregulated and 264 miRNAs were downregulated in keratinocytes. According to miRNA target prediction databases and the Expression Atlas database, 109 skin-related genes were obtained. Pathway enrichment analysis revealed 14 pathways including vesicle-mediated transport, signaling by interleukin, and others. Proteome profiling showed a significant upregulation of the epidermal growth factor (EGF) and Interleukin 1-alpha (IL-1α) compared to ADSCs. Integrated analysis through cross-matching the differentially expressed miRNA and proteins suggested two potential pathways for regulations of epidermal differentiation; the first is EGF-based through the downregulation of miR-485-5p and miR-6765-5p and/or the upregulation of miR-4459. The second is mediated by IL-1α overexpression through four isomers of miR-30-5p and miR-181a-5p.

Suprathel® or Mepilex® Ag for treatment of partial thickness burns in children: A case control study.

AIM: The study aim was to investigate if Suprathel® can be an adequate alternative to Mepilex® Ag for the treatment of partial-thickness scalds in children. METHODS: A retrospective study including 58 children admitted to The Burn Centre in Linköping, Sweden between year 2015 and 2022. Of the 58 children, 30 were dressed with Suprathel ® and 28 with Mepilex ® Ag. Outcomes investigated were healing time, burn wound infection (BWI), need for operations and number of dressing changes. RESULTS: We found no significant differences in any of the outcomes. In the Suprathel ® group 17 children and in the Mepilex ® Ag group 15 children were healed within 14 days. Ten children from each group received antibiotics for suspected BWI and two from each group underwent an operation with skin grafting. Each group had on median four dressing changes. CONCLUSIONS: Two different treatments were compared for children with partial-thickness scalds, and the data indicates that similar results are received with both dressings.

Experimental study of the effects of nitroglycerin, botulinum toxin A, and clopidogrel on bipedicled superficial inferior epigastric artery flap survival.

Beneficial effects could be achieved by various agents such as nitroglycerin, botulinum toxin A (BoTA), and clopidogrel to improve skin flap ischaemia and venous congestion injuries. Eighty rats were subjected to either arterial ischaemia or venous congestion and applied to a bipedicled U-shaped superficial inferior epigastric artery (SIEA) flap with the administration of nitroglycerin, BoTA, or clopidogrel treatments. After 7 days, all rats were sacrificed for flap evaluation. Necrotic area percentage was significantly minimized in flaps treated with clopidogrel (24.49%) versus the ischemic flaps (34.78%); while nitroglycerin (19.22%) versus flaps with venous congestion (43.26%). With ischemia, light and electron microscopic assessments revealed that nitroglycerin produced degeneration of keratinocytes and disorganization of collagen fibers. At the same time, with clopidogrel administration, there was an improvement in the integrity of these structures. With venous congestion, nitroglycerin and BoTA treatments mitigated the epidermal and dermal injury; and clopidogrel caused coagulative necrosis. There was a significant increase in tissue gene expression and serum levels of vascular endothelial growth factor (VEGF) in ischemic flaps with BoTA and clopidogrel, nitroglycerin, and BoTA clopidogrel in flaps with venous congestion. With the 3 treatment agents, gene expression levels of tumor necrosis factor-α (TNF-α) were up-regulated in the flaps with ischemia and venous congestion. With all treatment modalities, its serum levels were significantly increased in flaps with venous congestion and significantly decreased in ischemic flaps. Our analyses suggest that the best treatment option for ischemic flaps is clopidogrel, while for flaps with venous congestion are nitroglycerin and BoTA.

A prospective dual-centre intra-individual controlled study for the treatment of burns comparing dermis graft with split-thickness skin auto-graft.

To investigate if donor and recipient site morbidity (healing time and cosmesis) could be reduced by a novel, modified split-thickness skin grafting (STSG) technique using a dermal component in the STSG procedure (DG). The STSG technique has been used for 150 years in surgery with limited improvements. Its drawbacks are well known and relate to donor site morbidity and recipient site cosmetic shortcomings (especially mesh patterns, wound contracture, and scarring). The Dermal graft technique (DG) has emerged as an interesting alternative, which reduces donor site morbidity, increases graft yield, and has the potential to avoid the mesh procedure in the STSG procedure due to its elastic properties. A prospective, dual-centre, intra-individual controlled comparison study. Twenty-one patients received both an unmeshed dermis graft and a regular 1:1.5 meshed STSG. Aesthetic and scar assessments were done using The Patient and Observer Scar Assessment Scale (POSAS) and a Cutometer Dual MPA 580 on both donor and recipient sites. These were also examined histologically for remodelling and scar formation. Dermal graft donor sites and the STSG donor sites healed in 8 and 14 days, respectively (p < 0.005). Patient-reported POSAS showed better values for colour for all three measurements, i.e., 3, 6, and 12 months, and the observers rated both vascularity and pigmentation better on these occasions (p < 0.01). At the recipient site, (n = 21) the mesh patterns were avoided as the DG covered the donor site due to its elastic properties and rendered the meshing procedure unnecessary. Scar formation was seen at the dermal donor and recipient sites after 6 months as in the standard scar healing process. The dermis graft technique, besides potentially rendering a larger graft yield, reduced donor site morbidity, as it healed faster than the standard STSG. Due to its elastic properties, the DG procedure eliminated the meshing requirement (when compared to a 1:1.5 meshed STSG). This promising outcome presented for the DG technique needs to be further explored, especially regarding the elasticity of the dermal graft and its ability to reduce mesh patterns.Trial registration: ClinicalTrials.gov Identifier (NCT05189743) 12/01/2022.

A Systematic Review of Keratinocyte Secretions: A Regenerative Perspective.

Cell regenerative therapy is a modern solution for difficult-to-heal wounds. Keratinocytes, the most common cell type in the skin, are difficult to obtain without the creation of another wound. Stem cell differentiation towards keratinocytes is a challenging process, and it is difficult to reproduce in chemically defined media. Nevertheless, a co-culture of keratinocytes with stem cells usually achieves efficient differentiation. This systematic review aims to identify the secretions of normal human keratinocytes reported in the literature and correlate them with the differentiation process. An online search revealed 338 references, of which 100 met the selection criteria. A total of 80 different keratinocyte secretions were reported, which can be grouped mainly into cytokines, growth factors, and antimicrobial peptides. The growth-factor group mostly affects stem cell differentiation into keratinocytes, especially epidermal growth factor and members of the transforming growth factor family. Nevertheless, the reported secretions reflected the nature of the involved studies, as most of them focused on keratinocyte interaction with inflammation. This review highlights the secretory function of keratinocytes, as well as the need for intense investigation to characterize these secretions and evaluate their regenerative capacities.

Sociodemographic Patterns of Pediatric Patients in Specialized Burn Care in Sweden.

Trauma is a leading cause of mortality in children. Burns affect children disproportionally. Although burn incidence and mortality are decreasing, differences in the risk depend on socioeconomic status. The present study aimed to investigate the sociodemographic patterns of pediatric patients (0-17 years) managed at the two burn centers in Sweden, Uppsala, and Linköping, between 2010 and 2020. Method: This retrospective register-based study used hospital records from the two burn centers combined with information from Statistics Sweden plus data regarding number of asylum seekers from the Swedish Migrations Agency. Choropleth maps representing the patients' geographical distribution were created. Information about income levels per geographic area was added. A Wilcoxon signed-rank test was performed to investigate differences in median income levels between the areas where the patients lived, related to Sweden's median income. Results: The study included 2455 patients. Most of the children aged below 5 years (76%) and were boys (60%). The mean percentage of total skin area was 4.2%. There was no significant increment or decrease in the incidence of pediatric burns during the study. Most patients with recorded zip codes lived in areas with an income level below the national median (n = 1974, 83%). Children with asylum status were over-represented compared with residents and/or Swedish citizens. Conclusions: In Sweden, most pediatric burns occur in families that live in areas with low-income levels. Pediatric burns affect children with asylum status disproportionally compared with those who are residents in and/or citizens of Sweden. Prevention strategies should be designed and implemented to alleviate this health inequity.

Virtual planning of the anterolateral thigh free flap for heel reconstruction.

PURPOSE: three dimensional (3-D) virtual planning is an example of computer assisted surgery that improved management of composite tissue defects. However, converting the 3-D construct into two dimensional format is challenging. The purpose of this study was to assess 3-D virtual planning of complex heel defects for better optimized reconstruction. PATIENTS AND METHODS: a prospective analysis of 10 patients [9 male and 1 female; mean age = 27.9 years] with post-traumatic heel defects was performed. Heel defects comprised types II (three patients) or III (seven patients) according to Hidalgo and Shaw and were managed using anterolateral thigh (ALT) free flap adopting 3-D virtual planning of the actual defect which was converted into a silicone two dimensional mold. The mean definitive size of the defects was 63.4 cm3 . Functional, aesthetic, and sensory evaluations of both donor and recipient sites were performed 1 year after surgery. RESULTS: Six patients received thinned ALT (mean size = 139 cm3 ) while four patients received musculofasciocutaneous ALT flap (mean size = 199 cm3 ). One flap exhibited partial skin flap necrosis. Another flap was salvaged after re-exploration secondary to venous congestion. The mean follow-up was 20.2 months. The Maryland foot score showed 4 excellent, 5 good, and 1 fair cases. The mean American Orthopedic Foot and Ankle hind foot scoring was 76.3 (range: 69-86). All patients regained their walking capability. CONCLUSIONS: 3-D virtual planning of complex heel defects facilitates covering non-elliptical defects while harvesting a conventional elliptical flap with providing satisfactory functional outcomes and near-normal contour, volume, and sensibility.

Biomaterials as a Vital Frontier for Stem Cell-Based Tissue Regeneration.

Biomaterials and tissue regeneration represent two fields of intense research and rapid advancement. Their combination allowed the utilization of the different characteristics of biomaterials to enhance the expansion of stem cells or their differentiation into various lineages. Furthermore, the use of biomaterials in tissue regeneration would help in the creation of larger tissue constructs that can allow for significant clinical application. Several studies investigated the role of one or more biomaterial on stem cell characteristics or their differentiation potential into a certain target. In order to achieve real advancement in the field of stem cell-based tissue regeneration, a careful analysis of the currently published information is critically needed. This review describes the fundamental description of biomaterials as well as their classification according to their source, bioactivity and different biological effects. The effect of different biomaterials on stem cell expansion and differentiation into the primarily studied lineages was further discussed. In conclusion, biomaterials should be considered as an essential component of stem cell differentiation strategies. An intense investigation is still required. Establishing a consortium of stem cell biologists and biomaterial developers would help in a systematic development of this field.

ABO blood group and effects on ventilatory time, length of stay and mortality in major burns a retrospective observational outcome study.

Blood group has been found to be important in the development of many diseases and the outcome of several disease processes, especially cardiovascular morbidity and mortality, such as caused by trauma and sepsis. The main reason is claimed to be related to glycobiology and effects mediated through the endothelium. This study investigated the possible effect of blood group (ABO) on burn care outcome. Burn outcome prediction models are extremely accurate and as such can be used to identify outcome effects even in single centre settings. In this retrospective risk adjusted observational study, we investigated the effect of ABO blood group on ventilatory time, length of hospital stay (LOS), and 90 day mortality among patients with burns. RESULTS: A total of 225 patients were included (2008-2019) with median TBSA of 26%; interquartile range (IQR) of 20-37%; median age 45 years (IQR 22-65 years); median Baux score (age + TBSA%); 76 (IQR 53- 97); 168 (75%) were male; median duration of hospital stay was 31 days (IQR 19-56); a total of 138 (61%) received treatment with mechanical ventilation; and 29 (13%) died. In a multivariable regression model, we were unable to isolate any significant effect of any blood group (O, A, B, AB) on the outcome measures studied (ventilatory time, LOS, and mortality). IN SUMMARY: contrary to many other major areas of disease in which ABO blood groups affect outcome, we were unable to find any such effect on patients with burns. Given the precision of the outcome models presented (AUC 0.93) any such an effect, if missed due to the limited study cohort, may be considered limited and to have only a minor clinical impact.

Biosynthetic cellulose compared to porcine xenograft in the treatment of partial-thickness burns: A randomised clinical trial.

AIM: The aim was to compare two dressing treatments for partial-thickness burns: biosynthetic cellulose dressing (BsC) (Epiprotect® S2Medical AB, Linköping, Sweden) and porcine xenograft (EZ Derm®, Mölnlycke Health Care, Gothenburg, Sweden). METHODS: Twenty-four adults with partial-thickness burns were included in this randomized clinical trial conducted at The Burn Centers in Linköping and Uppsala, Sweden between June 2016 and November 2018. Time to healing was the primary outcome. Secondary outcomes were wound infection, pain, impact on everyday life, length of hospital stay, cost, and burn scar outcome (evaluated with POSAS). RESULTS: We found no significant differences between the two dressing groups regarding time to healing, wound infection, pain, impact on everyday life, duration of hospital stay, cost, or burn scar outcome at the first follow up. Burn scar outcome at the 12-month follow up showed that the porcine xenograft group patients scored their scars higher on the POSAS items thickness (p = 0.048) and relief (p = 0.050). This difference was, however, not confirmed by the observer. CONCLUSIONS: The results showed the dressings performed similarly when used in adults with burns evaluated as partial thickness.

Patient Reported Experiences at a Swedish National Burn Centre.

Previous studies have shown that burn patients were satisfied with the received care. Satisfaction was not strongly associated to burns or to psycho-social characteristics, suggesting that other factors, related to burn care specific aspects, may be important. The aim of this study was to analyze the independent effect of provided workload on the general satisfaction in adult patients at a Swedish national Burn Centre. The study population (n = 122) included patients ≥18 years, treated at the Linköping Burn Centre between 2016 and 2017. Experienced burn care was evaluated with the PS-RESKA survey (score range: 0-4), and provided workload was scored with the Burn Scoring System (BSC). Groups were compared with χ 2 test, MW test, or Fisher´s exact test. Multivariable logistic regression analyzed the independent effect of BSC on the outcome High Satisfaction (= score ≥3 to the survey-question: "How would you score your global experience at the Burn Centre?"). In-patients (n = 60) had more often larger burns and required more workload than out-patients (median[IQR]: TBSA% = 6.3 [3-12.3] % vs. 0.7 [0.3-2] %, p < .001; BSC = 65 [25.5-135.5] vs. 6 [4-9], p < .001). Both groups were highly satisfied with the experienced care (mean score [SD] = 3.68 [0.57] vs. 3.41 [0.77], p = .03). Neither characteristics of the patients (age, sex), nor TBSA% nor provided workload (BSC) were independently associated with High Satisfaction. Regardless of burn severity, demographics and provided workload, adult patients with burns were highly satisfied with the experienced burn care. This finding suggested that the reason of the satisfaction was multifactorial.