Frostbite injuries related to recreational nitrous oxide use: incidence, management, and complications in a Swedish case series.

Background: Nitrous oxide (N2O) use in recreational settings has been increasing in Sweden and Europe and consequently, the related injuries are also increasing. We aimed to investigate the incidence, management, and surgical outcomes of frostbite injury (FI) related to N2O use. Material and Method: All patients in a 22-month period from 2021 to 2022 presenting with FI related to N2O abuse from 2 plastic surgery clinics (1 national burn center) were identified. Data regarding patient comorbidity, mechanism of injury, initial management, treatment, and follow-up were investigated. Complications following surgery were categorized into minor (treated in outpatient setting) and major (requiring reoperation) complications. Results: In total, 9 patients were identified; among them, 5 patients provided consent and were included in the study. Direct contact with the gas canister was the most common injury mechanism (n = 4). All but 1 patient contracted full-thickness injuries, and these 4 patients later required surgery. The medial thigh was the most common area of injury. Outpatient clinic visits were common (mean 4.8 visits/patient). Surgical complications were common and all operated patients were diagnosed with minor complications and half of them with major complications (wound dehiscence and scar contracture). Conclusion: Frostbite injuries arising from recreational N2O use are complex and often require surgical intervention that may lead to complications. With the increasing incidence of N2O abuse in Sweden, further research is crucial to address this emerging public health concerns and optimize treatment strategies for these distinctive injuries.

A Study on Symptoms of Pelvic Floor Dysfunction in Assigned Female at Birth Patients Diagnosed with Gender Dysphoria Undergoing Vaginectomy.

Background: A person diagnosed with gender dysphoria who was assigned female at birth (AFAB) may request a vaginectomy as part of gender-affirming treatment. The aim of this study was to investigate the impact of vaginectomy on symptoms of pelvic floor dysfunction (PFD). Methods: This is a cohort study on patient-reported symptoms of PFD in patients who were AFAB, diagnosed with gender dysphoria, and undergoing vaginectomy in a single surgical center. Patients responded to a questionnaire preoperatively and 1 year postoperatively. The questionnaire consisted of 33 questions, including a modified short-form version of the Pelvic Floor Distress Inventory (PFDI-20). Results: Twenty-three consecutive patients were included in the study and 20 patients (87%) completed the 1-year follow-up. The preoperative median PFDI-20 score was 24 (0-114) compared with 32 (0-168) at the 1-year follow-up (P = 0.07). Patients who had previously undergone neophallus construction with a metoidioplasty (n = 15) had no significant change between the preoperative and the 1-year postoperative PFDI-20 score [median 17.5 (0-114) and 27.5 (0-145) (P = 0.65), respectively]; whereas those with a groin flap phalloplasty (n = 5) had a significant increase in reported symptoms [median 37 (10-95) and 124 (45-168), respectively (P = 0.04)]. Conclusions: Overall, vaginectomy could be performed without any major impact on symptoms of PFD. However, this seemed to be true mainly for patients with previous metoidioplasty, whereas patients with previous groin flap phalloplasty reported worsening of symptoms.

[Umbilical pilonidal sinus - a rare disease?] / Pilonidalsinus i naveln ­ ovanlig diagnos eller stort mörkertal?

Umbilical pilonidal sinus is a rare diagnosis which is characterized by an inflammatory granulomatous reaction to hair shafts penetrating the epidermis. It is most often seen in adolescent male with a hairy abdomen. The patients often present with a history of pain and umbilical discharge. Conservative treatment with hair extraction and personal hygiene is prioritized and surgery is only recommended in recurrent cases. Here one such case is presented, which was resistant to conservative treatment and where surgical excision and primary repair was indicated. No recurrence was observed 6 months postoperatively.

Development and evaluation of deep learning algorithms for assessment of acute burns and the need for surgery.

Assessment of burn extent and depth are critical and require very specialized diagnosis. Automated image-based algorithms could assist in performing wound detection and classification. We aimed to develop two deep-learning algorithms that respectively identify burns, and classify whether they require surgery. An additional aim assessed the performances in different Fitzpatrick skin types. Annotated burn (n = 1105) and background (n = 536) images were collected. Using a commercially available platform for deep learning algorithms, two models were trained and validated on 70% of the images and tested on the remaining 30%. Accuracy was measured for each image using the percentage of wound area correctly identified and F1 scores for the wound identifier; and area under the receiver operating characteristic (AUC) curve, sensitivity, and specificity for the wound classifier. The wound identifier algorithm detected an average of 87.2% of the wound areas accurately in the test set. For the wound classifier algorithm, the AUC was 0.885. The wound identifier algorithm was more accurate in patients with darker skin types; the wound classifier was more accurate in patients with lighter skin types. To conclude, image-based algorithms can support the assessment of acute burns with relatively good accuracy although larger and different datasets are needed.

[Diathermy can cause deep burns after alcohol preparation or through direct contact]. / Alkoholbaserade tvättlösningar kan ge brännskador vid diatermi.

Around 36 000 people seek care in Sweden due to burns annually. This usually requires repeated wound care and in some case surgery. Iatrogenic burns are rare but may be deep. One cause could be preparation of a patient with alcohol before surgery, or direct skin contact with a diathermic probe. In this case series we present two patients with this type of burns. These cases highlight the potential harm toward the patient, and it is important to have clear guidelines and take precautions when performing a diathermy.

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.

Accelerated wound healing in mice by on-site production and delivery of CXCL12 by transformed lactic acid bacteria.

Impaired wound closure is a growing medical problem associated with metabolic diseases and aging. Immune cells play important roles in wound healing by following instructions from the microenvironment. Here, we developed a technology to bioengineer the wound microenvironment and enhance healing abilities of the immune cells. This resulted in strongly accelerated wound healing and was achieved by transforming Lactobacilli with a plasmid encoding CXCL12. CXCL12-delivering bacteria administrated topically to wounds in mice efficiently enhanced wound closure by increasing proliferation of dermal cells and macrophages, and led to increased TGF-ß expression in macrophages. Bacteria-produced lactic acid reduced the local pH, which inhibited the peptidase CD26 and consequently enhanced the availability of bioactive CXCL12. Importantly, treatment with CXCL12-delivering Lactobacilli also improved wound closure in mice with hyperglycemia or peripheral ischemia, conditions associated with chronic wounds, and in a human skin wound model. Further, initial safety studies demonstrated that the topically applied transformed bacteria exerted effects restricted to the wound, as neither bacteria nor the chemokine produced could be detected in systemic circulation. Development of drugs accelerating wound healing is limited by the proteolytic nature of wounds. Our technology overcomes this by on-site chemokine production and reduced degradation, which together ensure prolonged chemokine bioavailability that instructed local immune cells and enhanced wound healing.

Want Correct Percentage of TBSA Burned? Let a Layman Do the Assessment.

Accurate determination of burn size significantly impacts both immediate management and long-term outcome. In the era of evidence-based medicine, the variability in TBSA% assessment shown by traditional methods may prove unacceptable and technology-aided systems become the "accepted standard." The objective of this study was to push this scenario to the limit by investigating the accuracy and consistency of TBSA% estimations using a computer-aided tool. Five Laymen (health care-burn management naïve people) were trained on the handling of the technology-aided assessment tool Burn Case 3D© and asked to calculate TBSA% for 18 clinical pictures of burns with different patterns and sizes. Forty-four burn Professionals (senior burn surgeons, plastic surgery residents, anesthesiologists, emergency physicians, senior registered nurses) were provided the same pictures and assessed TBSA% using traditional paper-based tools ("Rule of Palm"; "[Wallace] Rule of Nines"; "Lund and Browder chart). The Laymen's computer-aided calculations did not differ significantly (P > .05) from the senior burn surgeons' estimations in 17 of the 18 cases. However, when comparing the Laymen's TBSA% calculations with the whole group Professionals there were significant differences (P < .05) in (again) 17 of the 18 cases. Laymen's calculations were also more consistent (mean SD, 0.95%). The Professionals showed a generalized significant overestimation of TBSA% as compared with the Laymen's calculations (up to 198.5%). Innovative software provide a high potential to improve objectivity and quality of burn assessment in the future.

The state of the residential fire fatality problem in Sweden: Epidemiology, risk factors, and event typologies.

INTRODUCTION: Residential fires represent the largest category of fatal fires in Sweden. The purpose of this study was to describe the epidemiology of fatal residential fires in Sweden and to identify clusters of events. METHOD: Data was collected from a database that combines information on fatal fires with data from forensic examinations and the Swedish Cause of Death-register. Mortality rates were calculated for different strata using population statistics and rescue service turnout reports. Cluster analysis was performed using multiple correspondence analysis with agglomerative hierarchical clustering. RESULTS: Male sex, old age, smoking, and alcohol were identified as risk factors, and the most common primary injury diagnosis was exposure to toxic gases. Compared to non-fatal fires, fatal residential fires more often originated in the bedroom, were more often caused by smoking, and were more likely to occur at night. Six clusters were identified. The first two clusters were both smoking-related, but were separated into (1) fatalities that often involved elderly people, usually female, whose clothes were ignited (17% of the sample), (2) middle-aged (45-64years old), (often) intoxicated men, where the fire usually originated in furniture (30%). Other clusters that were identified in the analysis were related to (3) fires caused by technical fault, started in electrical installations in single houses (13%), (4) cooking appliances left on (8%), (5) events with unknown cause, room and object of origin (25%), and (6) deliberately set fires (7%). CONCLUSIONS: Fatal residential fires were unevenly distributed in the Swedish population. To further reduce the incidence of fire mortality, specialized prevention efforts that focus on the different needs of each cluster are required. PRACTICAL APPLICATIONS: Cooperation between various societal functions, e.g. rescue services, elderly care, psychiatric clinics and other social services, with an application of both human and technological interventions, should reduce residential fire mortality in Sweden.

Burn injury during long-term oxygen therapy in Denmark and Sweden: the potential role of smoking.

BACKGROUND: Long-term oxygen therapy (LTOT) increases life expectancy in patients with COPD and severe hypoxemia. Smoking is the main cause of burn injury during LTOT. Policy regarding smoking while on LTOT varies between countries. In this study, we compare the incidence of burn injury that required contact with a health care specialist, between Sweden (a country with a strict policy regarding smoking while on LTOT) and Denmark (a country with less strict smoking policy). METHODS: This was a population-based, cohort study of patients initiating LTOT due to any cause in Sweden and Denmark. Data on diagnoses, external causes, and procedures were obtained from the Swedish and Danish National Patient Registers for inpatient and outpatient care. Patients were followed from January 1, 2000, until the first of the following: LTOT withdrawal, death, or study end (December 31, 2009). The primary end point was burn injury during LTOT. RESULTS: A total of 23,741 patients received LTOT in Denmark and 7,754 patients in Sweden. Most patients started LTOT due to COPD, both in Sweden (74%) and in Denmark (62%). The rate of burn injury while on LTOT was higher in Denmark than in Sweden; 170 (95% confidence interval [CI], 126-225) vs 85 (95% CI, 44-148) per 100,000 person-years; rate ratio 2.0 (95% CI, 1.0-4.1). The risk remained higher after adjustment for gender, age, and diagnosis in multivariate Cox regression, hazard ratio 1.8 (95% CI, 1.0-3.5). Thirty-day mortality after burn injury was 8% in both countries. CONCLUSION: Compared to Sweden, the rate of burn injury was twice as high in Denmark where smoking is not a contraindication for prescribing LTOT.

A case report of a complete degloving injury of the penile skin.

INTRODUCTION: Male genital degloving injuries are unusual and rarely caused by animal bite. Usually patients attend health care immediately if bitten in the genital area. Prophylactic antibiotics is routinely used (Gomes et al., 2000). A penile degloving usually begins just proximal of the coronal line and progress down to the base of the shaft. Deep erectile tissue and the spermatic cord are seldom damaged and the endogenous skin of glans usually survives (Brown and Fryer, 1957; Morey et al., 2004; Finical and Arnold, 1999). PRESENTATION OF CASE: A heavily smoking man with a previous history of bladder cancer presented himself to the emergency department 24h after a dog bite degloved his penis. The avulsed skin was necrotic and subsequently excised. Antibiotic treatment was started. A bacterial swab was found positive for canine oral flora. The skin defect was closed using a 1:1 meshed split thickness skin graft from the inner thigh. Smoking cessation was encouraged. At the three month follow up the patient expressed satisfaction with both cosmetic and functional result and was now non-smoking. DISCUSSION: Several approaches to reconstruct penile skin exist. Split thickness skin graft has been lifted as a preferable alternative (Brown and Fryer, 1957; Finical and Arnold, 1999; Paraskevas et al., 2003) [5]. In this case, the avulsed skin was necrotic and could not be used. A 1:1 meshed split-thickness graft was chosen with excellent results. CONCLUSION: 1:1mesh of the graft can be recommended for easy attachment with a good functional and esthetical result. The potential risk of losing intimacy appearance or having to go through repeated procedures in the genital area motivated smoking cessation for this patient.

The risk of burn injury during long-term oxygen therapy: a 17-year longitudinal national study in Sweden.

BACKGROUND: Long-term oxygen therapy (LTOT) improves the survival time in hypoxemic chronic obstructive pulmonary disease. Despite warnings about potential dangers, a considerable number of patients continue to smoke while on LTOT. The incidence of burn injuries related to LTOT is unknown. The aim of this study was to estimate the rate of burn injury requiring health care contact during LTOT. METHODS: Prospective, population-based, consecutive cohort study of people starting LTOT from any cause between January 1, 1992 and December 31, 2009 in the Swedish National Register of Respiratory Failure (Swedevox). RESULTS: In total, 12,497 patients (53% women) were included. The mean (standard deviation) age was 72±9 years. The main reasons for starting LTOT were chronic obstructive pulmonary disease (75%) and pulmonary fibrosis (15%). Only 269 (2%) were active smokers when LTOT was initiated. The median follow-up time to event was 1.5 years (interquartile range, 0.55-3.1). In total, 17 patients had a diagnosed burn injury during 27,890 person-years of LTOT. The rate of burn injury was 61 (95% confidence interval, 36-98) per 100,000 person-years. There was no statistically significant difference in the rate of burn injury between ever-smokers and never-smokers, or between men and women. CONCLUSION: The rate of burn injuries in patients on LTOT seems to be low in Sweden. The strict requirements in Sweden for smoking cessation before LTOT initiation may contribute to this finding.

Hyaluronic acid, an important factor in the wound healing properties of amniotic fluid: in vitro studies of re-epithelialisation in human skin wounds.

Foetal wounds are unique in their ability to heal rapidly without forming scars. The amniotic fluid, rich in nutrients, growth factors, and hyaluronic acid, surrounds the foetus and is essential to foetal wound healing. The wound healing properties of foetal wounds may be the result of high concentrations of hyaluronic acid. This study aimed to verify that amniotic fluid induces re-epithelialisation in human skin wounds in vitro and to study whether this ability is dependent on hyaluronic acid. Standard deep dermal wounds were produced in vitro in human skin. The skin samples, with a central wound, were incubated in different culture media. Varying concentrations of amniotic fluid and amniotic fluid with added hyaluronidase were tested, and re-epithelialisation was assessed at 3, 7, and 12 days using light microscopy, after staining with haematoxylin and eosin. Amniotic fluid 50% resulted in a significantly higher (p < 0.05) grade of re-epithelialisation than Dulbecco's modified Eagle's medium and 10% amniotic fluid at all time points. When 50% amniotic fluid was compared with 10% foetal calf serum, no significant difference was found in grades of re-epithelialisation on days 3 and 12 and significantly higher grades of re-epithelialisation on day 7 (p < 0.05). Degradation of hyaluronic acid in the medium that contained 50% amniotic fluid gave significantly impaired re-epithelialisation (p < 0.05) on culture days 3 and 7. In conclusion, amniotic fluid promotes accelerated re-epithelialisation and hyaluronic acid is an important ingredient.

Use of macroporous gelatine spheres as a biodegradable scaffold for guided tissue regeneration of healthy dermis in humans: an in vivo study.

If a biodegradable scaffold is applied, the dermis can be regenerated by guided tissue regeneration. Scaffolds can stimulate in-growth of cells from the surroundings that migrate into them and start to produce autologous extracellular matrix as the scaffold is degraded. Several materials are available, but most of them are in the form of sheets and need to be laid on an open wound surface. A number of injectable fillers have been developed to correct soft-tissue defects. However, none of these has been used for guided tissue regeneration. We present a new technique that could possibly be used to correct dermal defects by using macroporous gelatine spheres as a biodegradable scaffold for guided tissue regeneration. In eight healthy volunteers, intradermal injections of macroporous gelatine spheres were compared with injections of saline and hyaluronic acid (Restylane). Full-thickness skin biopsy specimens of the implants and surrounding tissue were removed 2, 8, 12 and 26 weeks after injection, and the (immuno)histological results were analysed. The Restylane merely occupied space. It shattered the dermal tissue and compressed collagen fibres and cells at the interface between the implant and the dermis. No regeneration of tissue was found with this material at any time. The macroporous gelatine spheres were populated with fibroblasts already after 2 weeks. After 8 weeks the spheres were completely populated by fibroblasts producing dermal tissue. After 12 and 26 weeks, the gelatine spheres had been more or less completely resorbed and replaced by vascularised neodermis. There were no signs of capsular formation, rejection or adverse events in any subject. Further in vivo studies in humans are needed to evaluate the effect of the macroporous spheres fully as a matrix for guided tissue regeneration with and without cellular pre-seeding. However, the results of this study indicate the possibility of using macroporous gelatine spheres as an injectable, three-dimensional, degradable matrix for guided tissue regeneration.

Macroporous gelatine spheres as culture substrate, transplantation vehicle, and biodegradable scaffold for guided regeneration of soft tissues. In vivo study in nude mice.

In the course of development of a new type of filler for the correction of small defects in soft tissues we studied macroporous gelatine spheres as culture substrate, transplantation vehicle, and biodegradable scaffold for guided regeneration of soft tissues in vivo. We injected intradermally in nude mice gelatine spheres that had either been preseeded with human fibroblasts or preadipocytes, or left unseeded. We compared the extent of regenerated tissue with that found after injections of saline or single-cell suspensions of human fibroblasts or preadipocytes. Routine histological examinations and immunohistochemical staining for von Willebrand factor (indicating neoangiogenesis) were made after 7, 21, and 56 days. Injected saline or single-cell suspensions had no effect. However, a quick and thorough tissue regeneration with developing neoangiogenesis was elicited by the gelatine spheres and the effect of spheres preseeded with preadipocytes surpassed the effect of spheres preseeded with fibroblasts, which in turn surpassed the effect of unseeded gelatine spheres. We suggest that minor soft tissue defects such as wrinkles or creases can be corrected by injection of naked macroporous gelatine spheres, whereas larger defects are best corrected by injection of macroporous gelatine spheres preseeded with fibroblasts, or preadipocytes, or both.

Estradiol increases VEGF in human breast studied by whole-tissue culture.

Sex steroid exposure constitutes a risk factor for breast cancer, but little is known about the effects of sex steroids on the normal breast, largely because of the lack of convenient models. We have developed a method of culturing normal breast tissue ex vivo. We have applied this method to investigate the effects of estradiol and progesterone on the key angiogenic mediator, vascular endothelial growth factor (VEGF), in the breast. Whole breast tissue was obtained from routine reduction mammoplasty. Tissue biopsies were cultured in vitro for 1-3 weeks, and the expression of luminal cytokeratin 18 was determined by immunohistochemistry. As an application, tissue biopsies were treated in vitro for 1 week with or without estradiol or estradiol and progesterone. Estrogen receptor, progesterone receptor, and Ki-67 were analyzed, and VEGF levels were examined by quantitative immunoassay and immunohistochemistry. Whole breast tissue was cultured ex vivo for 1 week with preserved morphology. Increased detachment of the luminal epithelium was observed after 2 weeks. Estradiol increased extracellular levels of VEGF in normal breast tissue biopsy medium. The addition of progesterone had neither stimulatory nor inhibitory effects on secreted VEGF. The method of whole breast tissue culturing thus provide a means by which to explore the biology of normal breast tissue. Our results suggest that estradiol exerts pro-angiogenic effects in normal breast by increasing levels of biologically active VEGF.

Adipose tissue processed for lipoinjection shows increased cellular survival in vitro when tissue engineering principles are applied.

Correcting soft tissue defects by autologous fat grafting is a routine procedure in plastic surgery. Its efficacy and safety has been discussed extensively and several techniques of lipoinjection have been developed. However, one is bound to overcorrect by 30%-70% or need to repeat the procedure because of resorption of the transplant. The reasons are that many of the transplanted cells are already differentiated, and also that there is no nutritional support to the inner cell layers when they are transplanted as fragments. By culturing autologous adipocytes one can ensure that only non-differentiated, but committed, preadipocytes are transplanted and the procedure can be done in a way that ensures optimal nutritional support for the cells. In the present study we have compared our cell culture technique with two common clinical ways of processing liposuction material and found that (pre)adipocytes survive and proliferate significantly better in cell culture.