Bacterial bioburden of wounds: influence of debridement and negative-pressure wound therapy (NPWT).

OBJECTIVE: To clarify the role of microbiological swabs in surgical decision-making, we investigated the effect of negative-pressure wound therapy (NPWT) and serial surgical debridement on bacterial bioburden in hard-to-heal wounds and ultimately correlated them with the success of surgical closure. METHOD: All patients were treated with surgical debridement, jet lavage and NPWT before their wounds were finally closed. The treatment effect was assessed by correlating microbiological swabs obtained immediately after intervention with those obtained after removal of the dressings during the following surgical procedures. The result of the last microbiological swab taken before definitive surgical closure was correlated with the requirement for revision surgery. RESULTS: We included the results of 704 microbiological swabs from 97 patients in 110 wound localisations in this monocentric, retrospective study. NPWT did not improve bacterial bioburden in 77% of cases and the duration of NPWT did not affect the result. Furthermore, no significant effect of NPWT could be found for either anaerobic (p=0.96) or aerobic bacteria (p=0.43). In contrast, surgical debridement decreased bacterial load in approximately 60% of cases. If sterile wound swabs could be obtained at all, it was during the first four surgical debridements in 60% of patients; after that only 10% became sterile. CONCLUSIONS: Sterile microbiological wound swabs before surgical closure were associated with lower rates of revision surgery, while low or medium bacterial loads did not increase revision rates.

The Usage of Pedicled or Free Muscle Flaps Represents a Beneficial Approach for Periprosthetic Infection After Knee Arthroplasty.

INTRODUCTION: Periprosthetic joint infection (PJI) is a severe complication after a total knee replacement that is primarily associated with soft tissue defects. Finding an appropriate therapy for PJI is a major challenge because of the lack of guidelines and research comparing treatment options. METHODS: In this study, we retrospectively compared 78 patients who had a knee prosthetic infection within a mean follow-up period of 24 months. Group A received a soft tissue coverage in addition to orthopedic surgical therapy with or without a component replacement (CR) of the prosthesis. Group B received the same orthopedic treatment without plastic surgery for soft tissue coverage. RESULTS: Only 21% of the patients in group A received a CR compared with 70% in group B (P = 0.0001). In group A, 83% did not have a recurrent infection, and in group B, 57% of the patients had no further infection and regained joint function (P = 0.0376). In group A, only 15% of the patients who received a CR had a significant complication within the follow-up period of 2 years, whereas in group B, 75% of patients exhibiting a major complication (P = 0.0048*). CONCLUSIONS: Soft tissue coverage improves the outcome after PJI of the knee with soft tissue defects. Patients who simultaneously needed plastic surgery for defect coverage and orthopedic surgery for CR had the lowest number of complications overall. Based on the results of this study, a therapy algorithm could be identified considering the soft tissue defect grade leading to the lowest major complication rates and maximizing the outcome of knee prosthesis infection therapies.

Comparative Evaluation of the Angiogenic Potential of Hypoxia Preconditioned Blood-Derived Secretomes and Platelet-Rich Plasma: An In Vitro Analysis.

Blood-derived factor preparations are being clinically employed as tools for promoting tissue repair and regeneration. Here we set out to characterize the in vitro angiogenic potential of two types of frequently used autologous blood-derived secretomes: platelet-rich plasma (PRP) and hypoxia preconditioned plasma (HPP)/serum (HPS). The concentration of key pro-angiogenic (VEGF) and anti-angiogenic (TSP-1, PF-4) protein factors in these secretomes was analyzed via ELISA, while their ability to induce microvessel formation and sprouting was examined in endothelial cell and aortic ring cultures, respectively. We found higher concentrations of VEGF in PRP and HPP/HPS compared to normal plasma and serum. This correlated with improved induction of microvessel formation by PRP and HPP/HPS. HPP had a significantly lower TSP-1 and PF-4 concentration than PRP and HPS. PRP and HPP/HPS appeared to induce similar levels of microvessel sprouting; however, the length of these sprouts was greater in HPP/HPS than in PRP cultures. A bell-shaped angiogenic response profile was observed with increasing HPP/HPS dilutions, with peak values significantly exceeding the PRP response. Our findings demonstrate that optimization of peripheral blood cell-derived angiogenic factor signalling through hypoxic preconditioning offers an improved alternative to simple platelet concentration and release of growth factors pre-stored in platelets.

New Insights on Lipedema: The Enigmatic Disease of the Peripheral Fat.

BACKGROUND: Although a large number of adult women worldwide are affected by lipedema, the physiologic conditions triggering onset and progression of this chronic disease remain enigmatic. In the present study, a descriptive epidemiologic situation of postoperative lipedema patients is presented. METHODS: The authors developed an online survey questionnaire for lipedema patients in Germany. The survey was conducted on 209 female patients who had been diagnosed with lipedema and had undergone tumescent liposuction. RESULTS: Most of the participants (average age, 38.5 years) had noticed a first manifestation of the disease at the age of 16. It took a mean of 15 years to accomplish diagnosis. Liposuction led to a significant reduction of pain, swelling, tenderness, and easy bruising as confirmed by the majority of patients. Hypothyroidism [n = 75 (35.9 percent) and depression [n = 48 (23.0 percent)] occurred at a frequency far beyond the average prevalence in the German population. The prevalence of diabetes type 1 [n = 3 (1.4 percent)], and diabetes type 2 [n = 2 (1 percent)] was particularly low among the respondents. Forty-seven of the lipedema patients (approximately 22.5 percent) suffered from a diagnosed migraine. Following liposuction, the frequency and/or intensity of migraine attacks became markedly reduced, as stated by 32 patients (68.1 percent). CONCLUSIONS: Quality of life increases significantly after surgery with a reduction of pain and swelling and decreased tendency to easy bruising. The high prevalence of hypothyroidism in lipedema patients could be related to the frequently observed lipedema-associated obesity. The low prevalence of diabetes, dyslipidemia, and hypertension appears to be a specific characteristic distinguishing lipedema from lifestyle-induced obesity.

Adipose Stem Cells from Lipedema and Control Adipose Tissue Respond Differently to Adipogenic Stimulation In Vitro.

BACKGROUND: Lipedema is characterized by localized accumulation of fat in the extremities, which is typically unresponsive to dietary regimens or physical activity. Although the disease is well described and has a high incidence, little is known regarding the molecular and cellular mechanisms underlying its pathogenesis. The aim of this study was to investigate the pathophysiology of lipedema adipose cells in vitro. METHODS: Adipose-derived stem cells were isolated from lipoaspirates derived from lipedema and nonlipedema patients undergoing tumescent liposuction. In vitro differentiation studies were performed for up to 14 days using adipogenic or regular culture medium. Supernatants and cell lysates were tested for adiponectin, leptin, insulin-like growth factor-1, aromatase (CYP19A1), and interleukin-8 content at days 7 and 14, using enzyme-linked immunosorbent assays. Adipogenesis was evaluated by visualizing and measuring cytoplasmic lipid accumulation. RESULTS: Lipedema adipose-derived stem cells showed impeded adipogenesis already at early stages of in vitro differentiation. Concomitant with a strongly reduced cytoplasmic lipid accumulation, significantly lower amounts of adiponectin and leptin were detectable in supernatants from lipedema adipose-derived stem cells and adipocytes compared with control cells. In addition, lipedema and nonlipedema cells differed in their expression of insulin-like growth factor-1, aromatase (CYP19A1), and interleukin-8 and in their proliferative activity. CONCLUSIONS: The authors' findings indicate that in vitro adipogenesis of lipedema adipose-derived stem cells is severely hampered compared with nonlipedema adipose-derived stem cells. Lipedema adipose cells differ not only in their lipid storage capacity but also in their adipokine expression pattern. This might serve as a valuable marker for diagnosis of lipedema, probably from an early stage on.

In Vitro Characterization of Hypoxia Preconditioned Serum (HPS)-Fibrin Hydrogels: Basis for an Injectable Biomimetic Tissue Regeneration Therapy.

Blood-derived growth factor preparations have long been employed to improve perfusion and aid tissue repair. Among these, platelet-rich plasma (PRP)-based therapies have seen the widest application, albeit with mixed clinical results to date. Hypoxia-preconditioned blood products present an alternative to PRP, by comprising the complete wound healing factor-cascade, i.e., hypoxia-induced peripheral blood cell signaling, in addition to platelet-derived factors. This study set out to characterize the preparation of hypoxia preconditioned serum (HPS), and assess the utility of HPS-fibrin hydrogels as vehicles for controlled factor delivery. Our findings demonstrate the positive influence of hypoxic incubation on HPS angiogenic potential, and the individual variability of HPS angiogenic factor concentration. HPS-fibrin hydrogels can rapidly retain HPS factor proteins and gradually release them over time, while both functions appear to depend on the fibrin matrix mass. This offers a means of controlling factor retention/release, through adjustment of HPS fibrinogen concentration, thus allowing modulation of cellular angiogenic responses in a growth factor dose-dependent manner. This study provides the first evidence that HPS-fibrin hydrogels could constitute a new generation of autologous/bioactive injectable compositions that provide biochemical and biomaterial signals analogous to those mediating physiological wound healing. This therefore establishes a rational foundation for their application towards biomimetic tissue regeneration.

[DRG revenues and costs of multimorbid patients in the German DRG system - Analysis of the surgical treatment of chronic wounds at a university hospital based on the example of pressure ulcers]. / DRG Erlöse und Kosten multimorbider Patienten im deutschen DRG-System ­ Analyse der operativen Behandlung chronischer Wunden an einer Universitätsklinik am Beispiel des Dekubitus.

BACKGROUND: The treatment of complex patients with chronic wounds, such as pressure ulcers, is often not adequately reimbursed in patients with need for daily intensive care due to multimorbidity and chronic co-diagnoses. The present study analyses revenues, principle cost factors as well as possible complications. METHODS: We analysed 51 patients with the DRG principle diagnosis of decubitus stage III and IV, treated in our maximum care clinic in 2014 and 2015. Duration of stay, count of surgical procedures as well as frequency and type of complication were analysed. Costs and revenues per patient were calculated and compared to the mean costs stated by the institute of revenue and costs calculations (InEK). RESULTS: In 25 of 51 cases, the costs exceeded the revenues, which was due to an excessively long stay at the hospital, complications or a large number of operative procedures. On average, the patients could not be treated cost-efficiently at our clinic. CONCLUSION: The treatment of most multimorbid patients with decubital ulcers is often not adequately reimbursable within the German DRG system. A strict treatment algorithm with a reduced number of operations and intensive patient care are helpful approaches, but may not be sufficient to reduce cost-intensive complications. It seems important to re-evaluate the current DRG codes for these cases.

Lipofilling of Fingertips for Volume Defects after Fingertip Injuries.

INTRODUCTION: Regardless of the good outcomes of conservatively treated fingertip injuries, many patients complain about volume defects and hypoesthesia. Injection of autologous fat into the defect zone may resolve the volume problem and stimulate digital nerve regeneration by adipose derived stem cell transplantation. METHODS: We analyzed 5 volume defects resulting from conservatively treated fingertip injuries in 4 patients (male to female ratio, 2:2), 6 months after the injection of autologous abdominal fat into the defect zone retrospectively. The fat transplantation was performed after complete wound healing was achieved (2.5-13.5 months; mean, 6.5 months). Assessment of 2-point discrimination; finger pulp circumference; the Disability of the Arm, Shoulder, and Hand score; visual analog scale score; and a questionnaire regarding the treatment satisfaction were carried out both preoperatively and at a 6 month follow-up according to the standard of our clinic. RESULTS: In 3 patients, one session of lipofilling was sufficient to correct the contour, whereas 1 patient with 2 fingertip injuries was treated a second time. There was no significant change in finger pulp circumference, in the 2-point discrimination values and the Disability of the Arm, Shoulder, and Hand score results. There was a significant improvement in the visual analog scale scores in 4 of 5 cases, and all patients were very satisfied with the results of the procedure regarding the improvement in hand function in sports, at work and their daily routine. CONCLUSIONS: Lipofilling can be performed with little operative risks, might alleviate the patient's symptoms and reduce pain after conservative treatment of fingertip injuries.

The Fibrin Matrix Regulates Angiogenic Responses within the Hemostatic Microenvironment through Biochemical Control.

Conceptually, premature initiation of post-wound angiogenesis could interfere with hemostasis, as it relies on fibrinolysis. The mechanisms facilitating orchestration of these events remain poorly understood, however, likely due to limitations in discerning the individual contribution of cells and extracellular matrix. Here, we designed an in vitro Hemostatic-Components-Model (HCM) to investigate the role of the fibrin matrix as protein factor-carrier, independent of its cell-scaffold function. After characterizing the proteomic profile of HCM-harvested matrix releasates, we demonstrate that the key pro-/anti-angiogenic factors, VEGF and PF4, are differentially bound by the matrix. Changing matrix fibrin mass consequently alters the balance of releasate factor concentrations, with differential effects on basic endothelial cell (EC) behaviors. While increasing mass, and releasate VEGF levels, promoted EC chemotactic migration, it progressively inhibited tube formation, a response that was dependent on PF4. These results indicate that the clot's matrix component initially serves as biochemical anti-angiogenic barrier, suggesting that post-hemostatic angiogenesis follows fibrinolysis-mediated angiogenic disinhibition. Beyond their significance towards understanding the spatiotemporal regulation of wound healing, our findings could inform the study of other pathophysiological processes in which coagulation and angiogenesis are prominent features, such as cardiovascular and malignant disease.