Fabian Medved

Improvement of Split Skin Graft Quality Using a Newly Developed Collagen Scaffold as an Underlayment in Full Thickness Wounds in a Rat Model

IntroductionFrequently, full thickness skin defects were treated through split skin graft (SSG) transplantation. However, this is usually associated with a reduction of skin quality and scarring. In this context, a newly developed collagen cell carrier (CCC) has been evaluated as an underlayment in SSG transplantations in a rat model. Materials and MethodsTwenty-eight standardized full thickness skin defects were generated on the back of 28 adult male Lewis rats. The wounds were randomized and treated with SSG transplantation solitarily (n = 14) or SSG transplantation using CCC as an underlayment (n = 14). For skin quality analysis, a histological evaluation was performed 3 months postoperative in regard to epidermal cell count and epidermal and dermal thickness. ResultsWounds treated with SSG and CCC demonstrated a thicker epidermis and significantly higher epidermal cell count compared to SSG solitarily. At the time of evaluation, epidermal thickness of SSG and CCC was comparable to untreated, healthy skin (no statistically significant differences). DiscussionAs split skin grafting is frequently associated with skin quality reduction, the presented results reveal the beneficial effects of CCC in terms of skin graft quality improvement. This may offer unique opportunities in wound management and encourages further evaluation of CCC in surgical applications and regenerative medicine.

Angiogenese und Vaskularisation beim Tissue Engineering von Fettgewebe

The current standard for the reconstruction of large soft tissue defects with exposed bone, nerves or blood vessels, for example after extensive tumor resections, complex injuries, severe burns or infections, is the local or free microsurgical tissue transfer. Despite the development of new surgical techniques and many synthetic materials, there are still a large number of limitations and complications at the donor and recipient site. Thus, in a subset of patients either complete treatment is not possible or poses problems. Therefore, there is a great need for the development of new methods and materials allowing for a permanent replacement with body own soft tissue. A promising therapeutic approach is the soft tissue replacement with autologous adipose tissue. Innovative research on the reconstruction of soft tissue by adipose tissue, and clinical and experimental studies on the long-term survival and transplantation of autologous adipose tissue showed that the free fat tissue graft without direct vascular connection come along with disappointing results. Often a loss of volume or a complete resorption of the graft because of insufficient tissue quality by lack of cell differentiation was observed. This fact points to the special role of the maintenance and development of the grafts blood supply (angiogenesis and vascularization) crucial for maintaining a constant volume of the tissue. The rapidly growing interdisciplinary field of tissue engineering offers alternative solutions to the existing treatment options with the aim to produce autologous adipose tissue, stable in volume in vitro as well as in vivo, which can be transplanted as a permanent tissue replacement to corresponding parts of the body. Numerous studies have demonstrated the important and most critical factor of vascularisation for quality, volume and long-term survival of transplanted newly generated adipose tissue constructs. Although our understanding of the regulatory mechanisms of adipogenesis is still limited, there are clear indications that the complex sequences of cell interactions in the differentiation and proliferation of adipocytes is directly related to angiogenesis.

Infektionen nach sogenannten Bagatellverletzungen der Hand

ZusammenfassungHintergrundEine drohende folgenschwere Infektion ist bei bestimmten Verletzungen der Hand auf den ersten Blick oft nicht ersichtlich.FragestellungOft unterschätzte Verletzungen der Hand und häufige Infektionsrisiken werden erörtert, um zu einer realistischen Einschätzung der Prognose zu verhelfen.Material und MethodeEs wurde eine Literaturübersicht durchgeführt, um Infektionsrisiken der Hand und oft unterschätzte Verletzungsformen zu identifizieren. Die Infektionsrisiken und Verletzungsformen werden unter dem Aspekt der Früherkennung und der rechtzeitigen angemessenen Behandlung unter Berücksichtigung neuester wissenschaftlicher Veröffentlichungen diskutiert.ErgebnisseSchon geringe Entzündungszeichen bei bestimmten Patientengruppen, Wundeigenschaften, Fremdkörper- oder Biss- und Hochdruckinjektionsverletzungen sollten zu einem rechtzeitigen adäquaten chirurgischen Débridement veranlassen. Im Verlauf sollte regelmäßig geprüft werden, ob ein Missverhältnis in Bezug auf die Anzahl und die Virulenz der Keime und der Immunkompetenz des Patienten vorliegt, um ggf. erneut chirurgisch zu intervenieren. Die alleinige antibiotische Behandlung kann bei abgekapselten Prozessen oder einer Fremdkörperinkorporation die lokale infektbedingte Gewebezerstörung nicht aufhalten, birgt jedoch die Gefahr der Symptomverschleierung und somit der Infektionsverschleppung und einer Resistenzentwicklung.SchlussfolgerungenEin chirurgisches Débridement von Handverletzungen ist bei bestimmten Verletzungsmustern und Patientengruppen schon bei geringen Infektionszeichen angezeigt.AbstractBackgroundSerious infections resulting from seemingly harmless wounds are often difficult to predict.ObjectivesWe sought to identify often underestimated injuries of the hand and associated factors which may help to reliably predict the risk of infection.Materials and methodsA literature review was conducted to identify the risk of infections in small and superficial injuries of the hand as well as specific forms of injuries that are frequently underestimated. Reflecting the most recent literature, we discuss the risks of infection and seemingly harmless injury patterns that require prompt surgical intervention.ResultsEarly and adequate surgical debridement is highly recommended when minor signs of infection are present in susceptible patients or wounds, in case of foreign body injuries and bite injuries or in any high-pressure injection injury. Follow-up examinations at regular intervals are necessary to verify that immune response is strong enough to eliminate foreign invaders before their populations grow beyond control, mandating surgical intervention. Antibiotic treatment only is inadequate for encapsulated infections or foreign body injuries. However, it may dissimulate symptoms which would otherwise have led to consideration of surgical debridement and, therefore, delays appropriate treatment and may increase the risk of development of drug resistance.ConclusionSurgical debridement should not be delayed when minor signs of infection are present in susceptible patients or in specific patterns of injury of the hand.

Traumatische Ruptur eines Hydrogel-Brustimplantates: Ein Fall für die Berufsgenossenschaft?

Today textured breast implants for augmentation and reconstruction are commonly used to reduce the incidence of capsular contractures. Despite modified surfaces, capsular contracture may occur as result of traumatic or iatrogenic ruptures of the implant along with discharge of filling material.We report the interesting case of a female patient with traumatic rupture of one prosthesis in an industrial accident 14 years after implantation of hydrogel-filled breast prostheses. As it was a work related accident, the Employers Liability Insurance Association is responsible for covering the treatment. The patient history and the histological exam have proven that the accident was work related.

Ökonomischer Profit von Fingerverletzungen in einem handchirurgischen Zentrum – Replantation vs. Amputation

INTRODUCTION The Institute for Reimbursements in Hospital (InEK) annually provides an updated DRG system to ensure the medical service providers with a cost-covering remunera-tion. However, the underlying cost data are often opaque and disclosure of the basis of calculation does not take place. On the basis of cost and revenue data from our clinic between 2010 and 2012, a profit statement for amputations and replantation of one or more fingers was employed and compared with the nationwide data of the calculation clinics. MATERIALS AND METHODS Inpatient days, the revenue and the costs incurred in our clinic based on the cost matrix of InEK costing manual [4] were determined for amputation (DRG X05B), replantation of one (DRG X07B) and several fingers (DRG X07A). The profit was calculated as the difference between revenues and costs. Further-more, a comparison of our data with the nationwide data of InEK was applied. RESULTS For each of the 3 DRGs the actual costs in our clinic were higher than the costs generated by InEK. Only amputation appeared profitable, while all limb-preserving interventions were associated with losses for our hospital. There was a clear discrepancy between the data of cost of InEK GmbH to the data of our clinic. CONCLUSION In order not to create any monetary disincentives at the expense of quality of care of individual patients, a cost-covering patient care for all case groups mentioned above should be ensured. The general distrust in the InEKs data that results from such a discrepancy in the cost data can only be rebutted by increasing transparency and disclosure of the calculation basis.

Tissue Engineering von Fettgewebe mittels bioabbaubaren Biomaterialien zur Weichteildefektdeckung

Soft tissue defects resulting from injuries, tumor resection, congenital anomalies or chronic wounds pose a great challenge to reconstructive surgery. The current gold standard in therapy of such defects is the tissue transplantation in terms of free or local flaps. Unfortunately, donor site morbidity remains a considerable risk of flap surgery. Therefore, tissue engineering of autologous vascularized long term stable adipose tissue constructs could enrich the therapeutic possibilities of soft tissue defects. De novo adipose tissue growing requires fundamental knowledge about this kind of tissue and its synthesis, closely linked to angiogenesis. Bioresorbable biomaterials (scaffolds) are of crucial importance for adipose tissue engineering. Simulation or replacement of extracellular matrix for tissue growth by scaffold application requires a profound understanding of cell-matrix interactions. A proper biomaterial should be capable of supporting cell adherence, proliferation and differentiation. Important features are biocompatibility and resorption without toxic metabolites. In this review, various scaffold materials are discussed and novel achievements are presented. Persisting problems of de novo adipose tissue formation are high resorption rates and small tissue volumes of adipose constructs. Adipose tissue formation in a tissue engineering chamber is an additional possibility for in vivo tissue engineering. Recent studies proof that long term stable de novo adipose tissue formation of clinically relevant tissue volumes is possible. This method, in our opinion, has the potential to improve therapeutic strategies of soft tissue defects significantly.

Facial microcirculatory and biomechanical skin properties after single high energy (Er):YAG laser application

Owing to skin aging and the growing demand for skin rejuvenation, minimal invasive aesthetic treatments such as laser procedures are increasingly coming into focus. However, until now, little has been known about the objective effects of these procedures with respect to skin microcirculation or changes in skin elasticity.

Refinement of Tissue-Engineering Chamber Implantation in the Rat.

ABSTRACT Purpose: Rodent in vivo models that successfully generate new adipose, muscle, or vascular tissue in a tissue-engineering chamber (TEC) has advanced in the last decade. In this article, technical refinements in these operative foreign body implantations have been described to improve the execution of animal models in a way so that they can reduce wastage of time and resources. Materials & Methods: Male Sprague–Dawley rats were studied and randomly divided into two equal sized groups. In each group, a different operative procedure was used for implanting the TEC. Twenty animals were operated with diagonal incisions in the groin region, followed by staples for wound closure after TEC implantation. The remaining 20 animals received longitudinal incisions in the abdominal region followed by wound closure with ongoing intradermal nonresorbable sutures and skin glue. The outcome of both procedures with regard to complications, animal growth, and experimental failure was compared. Statistical analysis was performed using the nonparametric chi-squared (χ2) test. Results: Significant difference in wound dehiscence was recorded in Group I as compared to Group II (p = 0.0001). Consequently, 55% of the experiments had to be aborted in Group I and the animals were removed from the experiment. On the contrary, in Group II, all the animals could be kept. Conclusion: Median longitudinal incisions and thorough wound closure with ongoing intradermal nonresorbable sutures, followed by application of skin glue, are strongly recommended to prevent surgical site complications, such as wound dehiscence, animal harm, and failure of the individual experiment.

Dorsale Dislokation des Os trapezoideum: Ein Fallbericht

Die traumatische Dislokation des Os trapezoideum ist eine sehr seltene Verletzung der Handwurzel, die klinisch und radiologisch schwierig zu diagnostizieren ist [1]. Eine akute Luxation des Os trapezoideum aus dem Verbund der Handwurzelknochen setzt eine sehr starke direkte oder indirekte Krafteinwirkung voraus [2]. Häufiger luxiert das Os trapezoideum nach dorsal als nach palmar. Begleitverletzungen wie weitere Luxationen bzw. Frakturen der Hand sind häufig [3, 4]. Ohne angemessene Behandlung kann durch Verlust der karpalen Stabilität ein schwerer Schaden für die Hand entstehen mit vorzeitiger Arthrose und einem konsekutiven Funktionsverlust der Hand [5]. Wir berichten über einen 42-jährigen Patienten mit einer akuten, geschlossenen, dorsalen Luxation des Os trapezoideum aus dem Gefüge der Handwurzelknochen zusammen mit dem Mittelhandknochen (MHK) II sowie zusätzlicher dorsaler Luxation des MHK III im Karpometakarpalgelenk III und begleitenden subkapitalen Frakturen der MHK IV und V nach einem Motorradunfall. intakt. Die Sensibilität war mit einer 2-Punkte-Diskrimination von N1 bis N10 mit < 6 mm nach Weber ebenfalls nicht beeinträchtigt. In der Röntgenuntersuchung des Handgelenkes ergab sich der Verdacht auf eine karpometakarpale bzw. karpale Dislokation sowie eine MHK IV und V Kopffraktur (▶Abb. 1a, b). Zur weiteren Abklärung wurde eine Computertomografie des Handgelenkes und der Mittelhand durchgeführt. Hier zeigte sich eine dorsale karpale Dislokation des Trapezoideum im Verbund mit dem Mittelhandknochen II mit kleinen knöchernen Absprengungen am Kapitatum, Trapezium und Trapezoideum. Weiter ergaben sich eine Dislokation der MHK III Basis nach dorsal sowie subkapitale Frakturen der MHK IV und V (▶Abb. 1c, d). Noch am Vorstellungstag erfolgte nach Applikation eines Lokalanästhetikums (Scandicain 1 %) das Aushängen der Hand im Mädchenfänger mit einem Zuggewicht von 7 kg und der Versuch einer geschlossenen Reposition. Das CT nach Aushängen und Reposition ergab eine zwar verbesserte Stellung, es verblieb allerdings eine Subluxationsstellung zwischen Skaphoideum und Trapezoideum sowie zwischen Kapitatum und MHK III Kasuistik

Analysis of the two-point discrimination test in daily routine practice

BackgroundFinger nerve lesions lead to a sensory deficit with para-anesthesia or anesthesia and impair hand functions. In daily clinical practice, the diagnosis of an injured finger nerve can be challenging. This study aims at evaluating if the two-point discrimination (2PD) test is a good predictor of nerve lesions to indicate operative treatments in hand trauma patients.MethodsBased on the record of patients with an acute hand and finger injury, it was evaluated whether a pathological 2PD test in the clinical examination corresponds to the intraoperative findings of a severed nerve. From 2008 and 2014, patients with isolated finger nerve lesions were included, while patients with concomitant bone or tendon injuries were excluded.ResultsAs many as 113 patients with a total of 131 nerve injuries of the hand and fingers were suitable for this study. The statistical analysis revealed a sensitivity of 98% among them for the 2PD test. Further, a positive predictive value of 96% was demonstrated.ConclusionsThe results of our study showed that the 2PD test is a valuable examination to diagnose nerve injuries of fingers in hand trauma patients. It is a simple, reliable, and available examination tool and therefore can be suggested in daily clinical practice.Level of Evidence: Level III, diagnostic study.