A quantitative analysis of microcirculation during healing of split-thickness skin grafts in standardized full-thickness wounds.

BACKGROUND: Full-thickness skin defects often are managed with split-thickness skin grafting. The wound healing process, including formation of new vessels during the healing of skin grafts, is complex. OBJECTIVE: To evaluate the microcirculatory changes in the treated tissue after skin grafting to analyze perfusion dynamics during the wound healing process. MATERIALS AND METHODS: Fourteen full-thickness skin defects were created on the back of 14 adult male Lewis rats. All wounds were treated with autologous split-thickness skin grafts. The perfusion dynamics were assessed for 84 days with an O2C device that combines a laser light to determine blood flow and white light to determine postcapillary SO2 and the rHb. RESULTS: Blood flow increased for 50 days after grafting. SO2 decreased in superficial skin layers (depth of 2 mm) and increased in deep skin layers (depth of 8 mm) during the entire observation period. The rHb increased until day 10 in superficial layers and until day 20 in deep tissue layers. CONCLUSION: The microcirculatory changes reflect the different phases of wound healing. Long after the skin transplants were macroscopically healed, alterations in microcirculation were still detected. These alterations were caused by the long-lasting changes in tissue metabolism due to the formation, conversion, and degradation of the dermal matrix and vessels during wound healing and scar formation.

Severe Burn Injuries - The Day the Sodium Starts Rising.

BACKGROUND/AIM: The current study was designed to evaluate the etiologies of hypernatremic episodes in patients with severe burn injuries in comparison to critically ill non-burn patients. PATIENTS AND METHODS: The retrospective data acquisition was limited to the first 14 days and to patients with at least 20% total body surface area (TBSA) 2nd degree burn injuries or more than 10% TBSA when including areas of 3rd degree burn injuries. The results were compared to the results of a previously published study that analyzed the risk factors for hypernatremia in 390 non-burn intensive care unit patients. RESULTS: In total, 120 patients with a total of 50 hypernatremic episodes were included. Compared to non-burn injury patients, no significant differences were detectable except for a lower rate of hypokalemia and a higher rate of mechanical ventilation. The main trigger for hypernatremic episodes was the loss of free water, while 24% of the hypernatremic episodes seemed to be at least partly triggered by a surplus sodium influx. Patients with hypernatremic episodes had a significantly higher mortality rate. However, in none of the cases was hypernatremia the decisive cause of death. CONCLUSION: Besides the unique phenomenon of high volume internal and external volume shifts, the overall risk factors and etiologies of hypernatremia in patients with severe burn injury do not seem to significantly differ from other ICU patient collectives. Remarkably, a surplus of sodium influx and therefore a modifiable factor besides the specific burn injury volume resuscitation had an impact on the hypernatremic episodes in 24% of cases.

Mapping of Thoracodorsal Artery Perforators: Accuracy of Thermography and Handheld Doppler.

BACKGROUND: The versatile musculocutaneous latissimus dorsi flap and the thoracodorsal artery (TDA) perforator flap have developed into indispensable approaches in reconstructive surgery. While the anatomy of the TDA is consistent, the skin perforators vary in location and course. Dynamic infrared thermography (DIRT) recently gained popularity for perforator identification; however, its use and accuracy in thoracodorsal artery perforator (TDAP) mapping is yet to be determined. METHODS: TDAPs were visualized in 50 cases by DIRT. Based on the thermographic hotspots, the corresponding perforators were then identified by color duplex ultrasound (CDU) and handheld Doppler in a blinded fashion by two separate examiners. RESULTS: The midpoint of all perforator fascia passages was localized 99.7 mm caudal and 13.5 mm medial of the posterior axillary fold. The positive predictive value of perforator identification by dynamic infrared thermography was 86.5% and the correlating perforator fascia passage was 9.9 ± 5.8 mm from the hotspot midpoint, with a maximum of 29 mm. The positive predictive value of perforator identification by handheld Doppler was 95% and the signal was 7.2 ± 5.1 mm from the perforator fascia passage. CONCLUSION: DIRT precisely localizes TDAPs. The fusion with CDU combines both modalities' advantages. The combination with handheld Doppler is a fast way of perforator imaging, decreasing the handheld Dopplers' high false positive rate.

The Impact of Blue Light Irradiation on Keratinocytes in Vitro.

BACKGROUND: This study examined the effects of irradiation with blue light on HaCaT keratinocytes. As irradiation with blue light is known to be antimicrobial, it offers a promising alternative therapy for contaminated wounds. There is evidence that red light promotes wound healing, but the potential benefits of irradiation with blue light have not yet been adequately investigated. METHODS: The rate of wound closure in sterile and contaminated cells was measured using an in vitro scratch assay wound-healing model. Additionally, cell viability after treatment was determined using a Sulforhodamine B (SRB) assay. RESULTS: In both the sterile and contaminated groups, treated cells showed delayed wound closure when compared with cells not irradiated with blue light. Additionally, treatment with blue light resulted in poorer viability in the treatment groups. CONCLUSION: Although irradiation with blue light may offer a promising alternative therapy for reducing bacterial colonization, our data indicate that re-epithelization may be negatively influenced by blue light. Further research is needed to clarify possible wound healing applications.

The effect of weather and temporal factors on emergency hand trauma consultations.

INTRODUCTION: Fluctuations in the numbers of patient consultations in hand trauma emergency units are challenging in terms of both scheduling and the provision of sufficient resources. Trauma consultations in general are affected by both temporal and meteorological variables. As the genesis and epidemiology of hand trauma have their own characteristics, this study aimed to identify the influence of temporal and meteorological factors on hand trauma consultations. MATERIALS AND METHODS: All patients treated for hand trauma in our level one trauma center in 2019 were included in the study population and the data were analyzed in retrospect. The daily weather data, including temperature, sunshine duration, precipitation, humidity and wind speed, as well as temporal factors such as time of day, weekday and public holidays were considered and correlated with patient consultations. Gender differences were studied as well. RESULTS: We included 4787 hand trauma patients (66.4% male, mean age 38.4 ± 19.3 years, 31.7% occupational injuries). Significantly more consultations occurred on Saturdays as compared to weekdays (14.8 ± 0.6, n = 52 vs. 13.0 ± 0.2, n = 261; p = 0.028), and fewer occurred on official holidays (11.8 ± 0.5, n = 63 vs. 13.4 ± 0.2, n = 302; p = 0.0047). We found a significant positive correlation between daily consultations, sunshine duration (r = 0.14, p = 0.0056) and the mean temperature (r = 0.20, p < 0.0001); in contrast, a significant negative correlation between daily consultations and humidity (r = - 0.17, p = 0.001) was observed. Furthermore, fewer consultations were seen on days with precipitation (12.7 ± 0.3, n = 219 vs. 13.8 ± 0.3, n = 146; p = 0.009). The variation was considerably stronger in men. CONCLUSIONS: Hand trauma consultations increased with increasing temperatures, duration of sunshine, and decreasing humidity. Peak admissions were seen on Fridays and Saturdays. These findings can assist in predicting days with peak admissions to allocate resources appropriately.

Precision of Dynamic Infrared Thermography in Anterolateral Thigh Flap Planning: Identification of the Perforator Fascia Passage.

BACKGROUND: The anterolateral thigh (ALT) flap is commonly utilized in reconstructive surgery. Preoperative perforator mapping facilitates dissection. Dynamic infrared thermography can be applied to identify ALT perforators. However, its accuracy has not been evaluated in detail before. Therefore, this study aimed to assess the precision of dynamic infrared thermography in ALT perforator localization. METHODS: The survey site was defined as a 25 × 8 cm rectangle on the anterolateral thigh and a coordinate system was established. The area was examined consecutively by dynamic infrared thermography with a FLIR ONE camera after 2-minute fan precooling. Two surgeons then independently performed color duplex ultrasound on the basis of the identified hotpots. RESULTS: Twenty-four healthy subjects were examined. About 74.8% of perforators were musculocutaneous or musculoseptocutaneous. The mean distance between study area center and perforator or hotspot center was 51.8 ± 27.3 and 46.5 ± 26.2 mm, respectively. The mean distance from hotspot center to sonographic perforator fascia passage was 15.9 ± 9.9 mm with a maximum of 48.4 mm. The positive predictive value of thermographic ALT perforator identification was 93%. CONCLUSION: Thermographic hotspot and perforator location diverge widely in ALT flaps. Dynamic infrared thermography can therefore not be used as standalone technique for preoperative ALT perforator identification. However, the application before color duplex ultrasound examination is a reasonable upgrade and can visualize angiosomes and facilitate the examination.

Thermography Supported Color Duplex Ultrasound Accelerates ALT Perforator Imaging.

BACKGROUND: The anterolateral thigh flap is a versatile and dependable perforator flap and is a popular choice in the reconstruction of various body sites. The variable perforator anatomy suggests preoperative perforator imaging to improve safety and speed of dissection. An innovative perforator imaging technique is thermography, which lately gained attention in plastic surgery. METHODS: Thirty-two healthy participants were included in this randomized study. One thigh was examined with dynamic infrared thermography and consecutively with ultrasound, while the contralateral thigh was examined with ultrasound as standalone technology. RESULTS: The application of dynamic infrared thermography prior to ultrasound perforator identification significantly accelerated the ultrasound examination duration by 90 to 130 seconds. The mean duplex ultrasound examination duration correlated positively with the hotspot and perforator quantity per thigh. CONCLUSION: The addition of thermographic perforator mapping can accelerate color duplex ultrasound anterolateral thigh perforator imaging. Furthermore, thermography supplements color duplex ultrasound with crucial information on angiosome location.

Does leg dominance influence anterolateral thigh flap perforators?

INTRODUCTION: Thorough knowledge of perforator anatomy can facilitate anterolateral thigh (ALT) free flap harvest. The selection of the right or left thigh as donor area may be supported by preoperative perforator imaging and practical considerations. The study aims to determine if the leg dominance should be taken into account, when choosing the donor thigh for ALT free flap harvest, as muscle mass and perfusion might influence perforator quantity. METHODS: ALT perforators were localized by color-coded duplex sonography and dynamic infrared thermography on both thighs within a defined 250 × 80 mm area in 24 subjects. Perforator number and thickness of subcutaneous tissue and muscle layer were compared in dominant and nondominant legs. RESULTS: We found no statistically significant difference comparing sonographically identified ALT perforator numbers and hot spot numbers in dominant and nondominant legs. Yet, we found high interindividual differences. The comparison of subcutaneous tissue and muscle thickness yielded no significant difference. CONCLUSIONS: Our study yielded no evidence for preference of the dominant or nondominant leg in ALT free flap harvesting. As we found high interindividual differences in perforator number, we suggest to rely on preoperative perforator imaging when choosing the ALT free flap donor thigh.

Septic arthritis of the wrist: a retrospective review of 39 cases.

LEVEL OF EVIDENCE: III.

Immune-modulating properties of blue light do not influence reepithelization in vitro.

Phototherapy is gaining more attention in the treatment of various diseases. Especially, blue light seems to be a promising approach for wound healing promotion due to its antimicrobial and immune-modulating properties. Despite this, there is only little research focusing on the immune-modulating properties of blue light and its possible effects on wound healing. Therefore, we investigated the effects of blue light irradiation on peripheral blood mononuclear cells (PBMC) and the influence on reepithelization in vitro. PBMCs were irradiated with DermoDyne® (DermoDyne HealthCare, Berlin, Germany) and effects on cell viability, cytokine expression, and scratch wound closure were evaluated afterwards. Irradiated cells showed a higher Interleukin-γ concentration while irradiation reduced resazurin concentration in a time-dependent manner. No differences in reepithelization were detectable when keratinocytes were treated with the supernatant of these blue light irradiated PBMCs. Blue light-mediated ex vivo stimulation of PBMCs does not cause faster reepithelization in an in vitro setting. Further research is needed to investigate the wound healing effects of phototherapy with blue light.

Air Flow Cooling Improves Anterolateral Thigh Perforator Mapping Using the FLIR ONE Thermal Camera.

BACKGROUND: Due to the variable vascular anatomy preoperative perforator mapping facilitates anterolateral thigh (ALT) free flap harvesting. Dynamic infrared perforator imaging can assist preoperative planning by displaying hot spots that represent angiosomes. This study aims to compare previously described precooling methods to develop a standardized simplified protocol for ALT perforator planning. METHODS: Fifty thighs were examined with a FLIR ONE thermal camera. Four different cold challenges, including alcoholic disinfection, wet laparotomy sponge cooling, fan cooling, and cold pack application, were compared. Hot spot locations within a 250 mm × 80 mm area were compared double-blinded to perforator locations determined by Doppler ultrasonography considered as gold standard. RESULTS: The matching rate of thermographic hot spots and sonographically identified perforators was 34.9 ± 22.2%. An increased matching rate of 62.2 ± 42.2% was noted taking only favored perforators (septocutaneous course, diameter >1 mm, distance <3 cm to the center, and visible concomitant veins) into account. Precooling with a fan followed by alcoholic disinfection provided clearest thermograms and fastest results. CONCLUSION: Thermographic imaging is a reliable method for perforator imaging. Its supplemental use to ultrasound may reduce examination time and yield additional information. Precooling by air flow or alcoholic disinfection can be easily implemented and provide the best thermograms. The matching rate of thermographic hot spots and perforators increases when taking only clinically relevant perforators into account. Thermal perforator mapping therefore reduces distraction by negligible perforators.

The Influence of Topically Administered Heparin on Peripheral Microcirculation of the Skin: A Double-Blind, Randomized, Controlled Preliminary Study on 50 Healthy Subjects.

BACKGROUND: Venous thrombosis is the most common cause of flap failure in the first days after surgery. Although heparin is one of the most important antithrombotic substances and is implemented in the therapy of various diseases, there are only a few studies addressing its topical administration in the field of flap surgery. Especially, very little is known about the effects of topical heparin and its impact on microcirculation. In this study we evaluated to what extent topically administered heparin influences skin microcirculation (capillary venous oxygen saturation SO2, blood filling of microvessels, blood flow, and velocity) in healthy subjects. METHODS: Skin perfusion parameters on the forearm were measured with the O2C device in a double-blinded, controlled, and randomized study with 50 healthy subjects after administration of heparin ointment in three different concentrations and a control ointment (dexpanthenol). RESULTS: Topically administrated heparin slightly increased SO2 (max. 187 ± 285 SD or standard deviation % vs. 145 ± 129 SD %), flow (max. 264 ± 427 SD % vs. 151.74 ± 111 SD %), and velocity (max. 153 ± 149 SD % vs. 122 ± 56 SD %) after an incubation time of 60 minutes in comparison to control. No statistically significant difference could be detected regarding heparin concentration. CONCLUSION: As a first important step in possible future implementing of heparin as a topical administration in flap surgery, our data-although not statistically significant-indicate that heparin can improve microcirculation (SO2, flow) in healthy subjects. Nevertheless, further research in subjects with impaired microcirculation is necessary.

Does Phototherapy Promote Wound Healing? Limitations of Blue Light Irradiation.

INTRODUCTION: Phototherapy is gaining increased attention in the research and treatment of various diseases. In particular, the use of blue light seems to bear promise, owing to its antimicrobial and immune-modulating properties; however, research focused on the effects of blue light on keratinocytes and reepithelization is rare. In addition, few studies to date have evaluated devices that are used in daily hospital routine. OBJECTIVE: This study investigated the effects of phototherapy on keratinocytes with 2 established devices in vitro. MATERIALS AND METHODS: Human adult low calcium high temperature keratinocytes were irradiated with 2 different devices, and the effects on scratch wound closure, proliferation, cell viability, and cytokine expression were evaluated. RESULTS: Blue light irradiation reduced reepithelization at high doses in a scratch wound healing model (wound closure on day 1: control group, 25.57 percentage points [PP] ± 2.36 standard deviation vs Device A for 10 minutes, 1.33 PP ± 1.01) and mitochondrial activity measured with resazurin conversion (Device A for 10 minutes, 33.28% ± 12.34). Irradiated cells demonstrated a lower ratio of proliferating cell nuclear antigen-positive cells and, as a result, lower proliferation. CONCLUSIONS: Blue light reduces keratinocyte proliferation and migration at high doses and therefore could negatively affect wound healing. Available irradiation devices for possible use in wound therapy should be critically scrutinized and evaluated with in vitro methods prior to clinical use.

Microvascular tissue transfer after the resection of soft tissue sarcomas.

BACKGROUND: Microvascular tissue transfer enables the oncological resection of soft tissue sarcomas of the extremities and the trunk by covering the resulting tissue defects that are often extensive. This study was performed to investigate the long-term survival and functional outcome of patients treated with free flaps after sarcoma resection. METHODS: A total of 78 sarcoma patients received microvascular tissue transfer in our institution between March 2003 and January 2013. In a retrospective analysis, we investigated data such as tumor characteristics as well as survival time and disease-free survival. In a prospective analysis, we assessed the functional outcome and the health-associated quality of life with the TESS and SF-36 questionnaire, respectively. RESULTS: Seventy patients qualified for disease-free survival after tumor resection, 41 patients remained disease free for over 5 years. Forty-five patients reached a survival time of more than 5 years. The functional results experienced by our patients were good with a mean score of 82.6% in the TESS. The physical health-related quality was lower than in the German norm sample and patients suffering from chronical illnesses or cancer, whereas the mental health was only slightly lower than in the norm sample and higher than in the groups with chronic illnesses or cancer (SF-36). CONCLUSION: Microvascular tissue transfer enables tumor resection and limb salvage through the coverage of the resulting defects without impairing patients' prognosis. The long survival times after tumor resection emphasizes the need for good functional results as well as quality of life.

[Acute calcific periarthritis - a differential diagnosis of pyoarthrosis of the hand]. / Die akute kalzifizierende Periarthritis als Differentialdiagnose des Gelenkempyems an der Hand.

BACKGROUND: The acute calcific periarthritis is caused by hydroxyapatite deposits in the periarticular soft tissue.The symptoms resemble a pyoarthrosis, explaining high rates of misdiagnosis. PATIENTS: Presented are the cases of a 45 and a 46 years old patient, who presented with acute onset of swelling, erythema, functional impairment and pain of the hand. Periarticular calcifications were identified radiologically. RESULTS: The symptoms completely resolved in both patients within few days under conservative treatment. CONCLUSION: The acute calcific periarthritis should be considered as a differential diagnosis of pyoarthrosis in the hand, especially if no suitable trauma preceeded. Usually conservative treatment with immobilization and antiphlogistic drugs rapidly leads to a complete remission.

[Improvement in burn wound care: summary of the AWMF guideline for the treatment of thermal injuries in adults]. / Optimierung der chirurgischen Behandlung Brandverletzter: Auszüge aus der fachübergreifenden S2k-Leitlinie "Behandlung thermischer Verletzungen des Erwachsenen".

INTRODUCTION: More than half a million patients suffer from minor burns in Germany per year. In 2018, almost 2000 patients needed intensive care for their burn injuries. Despite high standards of burn care, mortality remains high. Burn injuries may lead to long-term sequelae. In order to provide up-to-date burn care, guidelines are available online with public access. METHODS AND RESULTS: This overview presents a summary of the German AWMF guideline for the treatment of thermal injuries in adults (https://www.awmf.org/leitlinien/detail/ll/044-001.html). Experts of eleven different medical organisations and specialties have contributed to this S2k guideline with their expertise. The focus of the article is on acute burn wound assessment, the indication for specialised care in burn centres, the management of the burn wound at the trauma scene and in hospitals as well as scar management and rehabilitation. CONCLUSION: This overview reports on the consensus-based treatment of acute burn wounds in adults in Germany. The article is intended to guide doctors and professional caretakers to perform state-of-the-art burn care. The current guideline aims to improve burn outcome.

Influence of Topical Anesthesia on Superficial Sensitivity: A Double-Blind, Randomized, Placebo-Controlled Study on 48 Healthy Subjects.

BACKGROUND: Topical anesthetics are used in noninvasive transdermal anesthesia to decrease the superficial pain sensation threshold during dermatologic surgery. Combined pain relief and sensitivity loss can avoid discomfort during the surgery. OBJECTIVE: The aim of this placebo-controlled study was to compare the efficacy of 3 commonly used topical agents by collating loss of sensitivity over time. MATERIALS AND METHODS: Three topical anesthetic creams, a topical anti-inflammatory cream, and a moisturizing cream were applied on the left volar forearm of each of the 48 healthy Caucasian participants. Sensitivity was assessed with the dynamic 2-point discrimination and the Semmes-Weinstein test at 0, 60, 90, 120, 150, and 180 minutes after cream application. RESULTS: After 180 minutes, benzocaine showed a significantly lower 2-point discrimination reduction than lidocaine alone and a lidocaine and prilocaine mixture. Sensory threshold measurements by the Semmes-Weinstein test after 60 minutes revealed a significantly higher effect with lidocaine alone and with the lidocaine and prilocaine mixture than with benzocaine. CONCLUSION: The authors found a stronger skin sensitivity reduction by the eutectic lidocaine and prilocaine mixture and lidocaine alone compared with benzocaine. We suggest increased discomfort reduction in topical anesthetic supported dermatologic surgery by the eutectic mixture and lidocaine alone.

A quantitative study of hydration level of the skin surface and erythema on conventional and microclimate management capable mattresses and hospital beds.

BACKGROUND: In addition to pressure itself, microclimate factors are gaining more attention in the understanding of the development of pressure ulcers. While there are already various products to reduce pressure on sore-prone areas to prevent pressure ulcers, there are only a few mattresses/hospital beds that actively influence skin microclimate. In this study, we investigated if microclimate management capable mattresses/hospital beds can influence skin hydration and skin redness/erythema. METHODS: We included 25 healthy subjects in our study. Measurements were made using Courage & Khazaka Multi Probe Adapter MPA with Corneometer CM825 and Mexameter MX18 to determine skin hydration of the stratum corneum and skin redness/erythema before and after the subjects were lying in conventional (Viskolastic® Plus, Wulff Med Tec GmbH, Fedderingen, Germany and Duo™ 2 mattress, Hill-Rom GmbH Essen, Germany) or microclimate management capable mattresses/hospital beds (ClinActiv + MCM™ and PEARLS AFT, Hill-Rom GmbH Essen, Germany). RESULTS: While there was no difference in skin redness/erythema on the different mattresses/hospital beds, skin hydration of the stratum corneum decreased significantly in an air fluidized bed compared to baseline values and values measured on standard mattress/Viskolastic® Plus. CONCLUSION: Air-fluidized therapy reduces skin hydration and therefore could contribute to prevent moisture associated ulcers. Changes in skin hydration as one important factor of skin microclimate can be detected after a short time of incubation and even before an erythema appears.

A quantitative study of transepidermal water loss (TEWL) on conventional and microclimate management capable mattresses and hospital beds.

BACKGROUND: Transepidermal water loss (TEWL) is regarded as one of the most important parameters characterizing skin barrier integrity and has found to be higher in impaired skin barrier function. Reduced or low TEWL instead indicates skin barrier integrity or improvement. We evaluated if different mattresses/hospital beds can influence this skin barrier function by measuring TEWL before and after subjects lying in conventional and microclimate management capable mattresses/hospital beds. METHODS: We included 25 healthy subjects in our study. Measurements were made using Courage & Khazaka Multi Probe Adapter MPA with Tewameter TM300 to determine TEWL before and after the subjects were lying in conventional (Viskolastic® Plus, Wulff Med Tec GmbH, Fedderingen, Germany and Duo™ 2 mattress, Hill-Rom GmbH Essen, Germany) or microclimate management capable mattresses/hospital beds (ClinActiv + MCM™ and PEARLS AFT, Hill-Rom GmbH Essen, Germany). RESULTS: While there was no statistically significant difference in standard mattresses/hospital beds (22.19 ±â€¯12.99 and 19.80 ±â€¯11.48 g/hm2), the decrease of TEWL was statistically significant in both microclimate management capable mattresses/hospital beds we investigated (16.89 ±â€¯8.586 g/hm2 and 17.41 ±â€¯7.203 g/hm2) compared to baseline values (35.85 ±â€¯24.51 g/hm2). CONCLUSION: As higher TEWL announces impaired skin barrier function these findings indicate that the choice of the mattress/hospital bed is important for skin barrier function and microclimate management systems improve skin barrier function of the skin.