Wound closure is a key element of any procedure, especially aesthetic and reconstructive plastic surgery. Therefore, over the last decades, several devices have been developed in order to assist surgeons in achieving better results while saving valuable time. In this work, we give a concise review of the literature and present a biomechanical study of different suturing materials under mechanical load mimicking handling in the operating theatre. Nine different suture products, all of the same USP size (4-0), were subjected to a standardized crushing load by means of a needle holder. All materials were subjected to 0, 1, 3 and 5 crushing load cycles, respectively. The linear tensile strength was measured by means of a universal testing device. Attenuation of tensile strength was evaluated between materials and between crush cycles. In the pooled analysis, the linear tensile strength of the suture materials deteriorated significantly with every cycle (p < 0.0001). The suture materials displayed different initial tensile strengths (in descending order: polyglecaprone, polyglactin, polydioxanone, polyamid, polypropylene). In comparison, materials performed variably in terms of resistance to crush loading. The findings were statistically significant. The reconstructive surgeon has to be flexible and tailor wound closure techniques and materials to the individual patient, procedure and tissue demands; therefore, profound knowledge of the physical properties of the suture strands used is of paramount importance. The crushing load on suture materials during surgery can be detrimental for initial and long-term wound repair strength. As well as the standard wound closure methods (sutures, staples and adhesive strips), there are promising novel devices.

Mit Beginn des Zeitalters des sog. Tissue Engineering (TE) wurden experimentelle Versuchsanordnungen entwickelt, die einen geschlossenen Umgebungsraum mit optimierten Bedingungen für Zellwachstum oder Produkterzeugnis definieren sollten. Diese Systeme wurden als „Bioreaktoren“ bezeichnet. Durch die Übertragung des „Bioreaktor-Prinzips“ in den biomedizinischen Sektor wurden Entwicklungen der Biomaterialwissenschaften und der Zellbiologie in einer neuen integrativen Forschungsdisziplin vereint. Auch im Zeitalter der regenerativen Medizin (RegMed) stellt die Übertragung der Ergebnisse auf in vivo Bedingungen und somit auf die zukünftige klinische Anwendung die größte He­rausforderung dar. Ziel des Bioreaktors ist es, diesen in vivo Bedingungen gerecht zu werden, um damit die Integration neu geschaffenen Gewebes in einen lebenden Organismus zu gewährleisten. Moderne in vivo Bioreaktoren werden heute als integraler Bestandteil des lebenden Organismus verstanden. Die Zellvermehrung und Gewebereifung steht hierbei von Beginn an unter den Einflüssen und physiologischen Wechselwirkungen des Empfängerorganismus. Neueste Entwicklungen aus Gebieten wie die rekonstruktive Chirurgie (arteriovenöse Gefäßschleife zur Organzüchtung) und das moderne Wundmanagement (die topische Unterdrucktherapie als perfusions-Bioreaktor) sollten neue Impulse für die Übertragbarkeit der Reg-Med-Konzepten in den klinischen Alltag liefern. With the advent of the era of tissue engineering (TE), experimental settings have been developed that allow for a defined environment with optimised cell growth conditions and/or the production of specific substitutes. These isolated systems have been termed “bioreactors”. By translating the principles of bioreactors into an in vivo context, advances in biomaterial sciences and cell biology have been merged into an integrative research concept. Even today, in the age of regenerative Medicine (RegMed) the transfer of experimental in vitro findings into a clinical in vivo approach still remains a vast challenge. In order to fulfil these specific requirements bioreactors had to be defined anew. Latest advances in areas like reconstructive medicine (the arteriovenous loop as a means of organogenesis) or modern wound management (topical negative pressure therapy as a perfusion bioreactor) give new impulses towards the translation of Reg-Med concepts into the clinical routine.

The aim of this in vivo study was to gather quantitative information on the three-dimensional morphology of a new vascular network under the influence of angioactive growth factors. For this purpose, the arteriovenous loop model was used in 10 Lewis rats to generate a bioartificial vascular assembly by means of vascular induction. In this model, an isolated organoid is created in the medial thigh of the animal by methods of tissue engineering. A fibrin gel containing vascular endothelial growth factor (VEGF¹⁶⁵) and basic fibroblastic growth factor (bFGF) was used as a matrix in the effect group (GF+). Fibrin matrices devoid of growth factors were used as controls (GF−). A microvascular replica of the organoid was created by means of corrosion casting and the network was investigated on stereo-paired images obtained by scanning electron microscopy. Vectors of intercapillary and interbranching distances as well as the diameter of the pores in the intussusceptive events diameter and the ratio of sprouting versus intussusceptive angiogenic events were compared in the two groups. The results were highly significant. In the GF+ group there were more profound three-dimensional morphological traits of angiogenesis, whereas advanced neovascularisation in the phase of remodelling was demonstrated by a higher incidence of intussusception, compared to control. These results illustrate the importance of morphological studies with focus on the generation of three-dimensional vascular networks.

In this study, we evaluated a new aspect of negative pressure wound therapy (NPWT) as an analytical tool for pharmacokinetic studies. Twenty‐one patients with soft tissue defects scheduled to receive NPWT were included in this study. Concomitant to NPWT, all patients received intravenous moxifloxacin (MX). At different time intervals, blood plasma levels of MX were sampled and compared with synchronous concentrations of MX in the exudate obtained from the NPWT drainage system. Serial measurements were performed upon initiation of the therapy as well as in the steady state (after 5 days). At steady state, wound tissue was obtained intraoperatively. High‐performance liquid‐chromatography (HPLC) was used for analysis. At 1 hour post‐administration, the exudate/plasma levels (mg/L) were 1.92/3.07; at 12 hours, 0.80/1.14; at 24 hours, 0.26/0.43; and at 120 hours (steady state), 0.42/0.47. There was a correlation between exudate and plasma levels reaching approximately 0.75. Until now, methods for pharmacokinetic studies concerning interstitial fluid are difficult to apply in the clinical context. The presented method showed limitations, but we believe that, after methodological improvements, measurements of substances in the interstitial fluid by means of NPWT are feasible.

Bone Allograft and Locking Plate for Severe Proximal Humeral Fractures: Early and Late Outcomes - Article abstract #928982