Suspected Simple Appendicitis in Children: Should We Use a Nonoperative, Antibiotic-Free Approach? An Observational Study.

BACKGROUND: Simple appendicitis may be self-limiting or require antibiotic treatment or appendectomy. The aim of this study was to assess the feasibility and safety of a nonoperative, antibiotic-free approach for suspected simple appendicitis in children. METHODS: This single-center, retrospective study included patients (0-17 years old) who were hospitalized at the pediatric surgery department due to suspected appendicitis between 2011 and 2012. Data from patients who primarily underwent appendectomy were used as controls. The follow-up of nonoperatively managed patients was conducted in 2014. The main outcome of interest was appendicitis recurrence. RESULTS: A total of 365 patients were included: 226 were treated conservatively and 139 underwent appendectomy. Fourteen (6.2% of 226) of the primarily nonoperatively treated patients required secondary appendectomy during follow-up, and histology confirmed simple, uncomplicated appendicitis in 10 (4.4% of 226) patients. Among a subset of 53 patients managed nonoperatively with available Alvarado and/or Pediatric Appendicitis Scores and sonographic appendix diameters in clinical reports, 29 met the criteria for a high probability of appendicitis. Three of these patients (10.3% of 29) underwent secondary appendectomy. No complications were reported during follow-up. CONCLUSIONS: A conservative, antibiotic-free approach may be considered for pediatric patients with suspected uncomplicated appendicitis in a hospital setting. Only between 6 and 10% of these patients required secondary appendectomy. Nevertheless, the cohort of patients treated nonoperatively was likely to have also included individuals with further abdominal conditions other than appendicitis. Active observation and clinical support during the disease course may help patients avoid unnecessary procedures and contribute to spontaneous resolution of appendicitis or other pediatric conditions as the cause of abdominal pain. However, further studies are needed to define validated diagnostic and management criteria.

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.

Interpretable and intervenable ultrasonography-based machine learning models for pediatric appendicitis.

Appendicitis is among the most frequent reasons for pediatric abdominal surgeries. Previous decision support systems for appendicitis have focused on clinical, laboratory, scoring, and computed tomography data and have ignored abdominal ultrasound, despite its noninvasive nature and widespread availability. In this work, we present interpretable machine learning models for predicting the diagnosis, management and severity of suspected appendicitis using ultrasound images. Our approach utilizes concept bottleneck models (CBM) that facilitate interpretation and interaction with high-level concepts understandable to clinicians. Furthermore, we extend CBMs to prediction problems with multiple views and incomplete concept sets. Our models were trained on a dataset comprising 579 pediatric patients with 1709 ultrasound images accompanied by clinical and laboratory data. Results show that our proposed method enables clinicians to utilize a human-understandable and intervenable predictive model without compromising performance or requiring time-consuming image annotation when deployed. For predicting the diagnosis, the extended multiview CBM attained an AUROC of 0.80 and an AUPR of 0.92, performing comparably to similar black-box neural networks trained and tested on the same dataset.

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.

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.

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.

Complement activation at the interface of wound dressings and blood does not influence keratinocyte migration/proliferation in vitro.

Recently, we reported that some wound dressings caused complement activation at the interface of wound dressing and blood. Since complement activation is associated with impaired wound healing, we investigated whether this activation of the complement cascade at the interface of wound dressings and blood does impair reepithelialization in a scratch wound healing assay. Although some samples showed higher levels of the complement activation marker SC5b-9 in our study, reepithelialization of the samples did not significantly differ from the control group. Further studies have to clarify if complement activation at the interface of wound dressings and blood plays a relevant role in the healing process especially in long-time experiments.

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.

Hemocompatibility of different burn wound dressings.

A variety of wound dressing are available for burns. Furthermore, although their impacts on wound healing have been studied sufficiently, their effects on blood remain unclear. Meanwhile, this aspect is extremely important, since blood interacts with the wound dressing, especially in extensive burn injuries. Therefore, the aim of this study is to evaluate the hemocompatibility and immunogenicity of different burn wound dressings. Accordingly, human whole blood (n = 5) was anticoagulated with heparin, treated with different wound dressings and incubated at 37°C for 30 minutes. Different parameters for coagulation and hemocompatibility were evaluated before and after incubation. Consequently, Jelonet, Xenoderm, and Matriderm showed higher TAT-III concentrations, Jelonet, Xenoderm, EZ Derm, and Matriderm were higher ß-thromboglobulin; EZ Derm and Burntec showed higher SC5b-9 concentrations after incubation with whole blood. Our ex vivo study provided initial insights into the hemocompatibility and immunogenicity of different burn wound dressings. Moreover, Xenografts (Xenoderm and EZ Derm), Jelonet and Matriderm showed a hemostyptic effect, while EZ Derm and Burntec activated the complement system. Therefore, further studies must be conducted to analyze the possible effects in vivo.

Keratinocyte Growth Factor Modified Messenger RNA Accelerating Cell Proliferation and Migration of Keratinocytes.

Keratinocyte growth factor (KGF) plays a central role in wound healing as it induces cell proliferation and motility. The use of growth factors such as KGF is therefore viewed as a promising approach in wound therapy, although effective application remains a major problem because of inactivation and the resulting short half-life of applied growth factors in wound beds. Therefore, the rational of this study was to develop and investigate an innovative strategy to improve wound healing using an in vitro-transcribed modified KGF messenger RNA (mRNA). After transfection of cells, we evaluated the effects of the produced KGF protein on cell migration and reepithelialization of keratinocytes using a scratch assay. The results demonstrate that KGF-mRNA-transfected cells exhibited a high KGF protein release that is sufficient to significantly improve reepithelialization in the performed scratch assays. Transfection with growth factor mRNA therefore seems to be a promising therapeutic strategy, especially for difficult wounds, as it leads to a temporary increase of growth factor expression in the treated wound area without interfering with the DNA of the nucleus, as seen in gene therapeutic applications.

Hemostyptic property of chitosan: Opportunities and pitfalls.

BACKGROUND: Chitosan is used in a wide field of applications and therapies and has been reported to be an effective hemostyptic. The objective of this study was to provide further information about the use of chitosan as a hemostyptic agent also taking into focus its hemocompatible effects. METHODS: Human whole blood (n=5) was anticoagulated with heparin, treated with different chitosan concentrations (0, 2.5, 5, 7.5, 10, 12.5, 25 mg/mL) and incubated at 37°C for 30 minutes. Before and after incubation different parameters for coagulation and hemocompatibility were evaluated. RESULTS: Blood treated with high chitosan concentrations showed enhanced coagulation, which we evaluated with activated clotting time, activated partial thromboplastin time and concentration of thrombin-antithrombin complexes. Furthermore, we observed an activation of blood platelets, complement cascade and granulocytes in the groups treated with chitosan. CONCLUSION: Our data indicate that chitosan activates human blood coagulation and hence has good properties as a hemostyptic agent. However, inflammatory parameters were upregulated after direct contact with human blood indicating that systemic administration of chitosans should not be performed whereas the topical use of chitosan as a hemostypticum should not present any hazard with regard to adverse inflammatory reactions at the site of application.