The results confirmed a reduced superficial SSI rate after vascular surgical groin incision using ciNPT compared with standard wound dressings.

Mesh biocompatibility is basically determined by the foreign body reaction (FBR). In contrast to physiological wound healing and scar formation, the FBR at the host-tissue/biomaterial interface is present for the lifetime of the medical device. The cellular interactions at the mesh/tissue interface proceed over time ending up in a chronic inflammatory process. The time course of the FBR has been studied extensively and consists of three crucial steps that are protein absorption, cell recruitment and, finally, fibrotic encapsulation and extracellular matrix formation. Each of these steps involves a complex cascade of immune modulators including soluble mediators and various cell types. Recent research has focused on the cellular and molecular interactions of the distinct phases of the FBR offering a new basis for therapeutical strategies. The highly dynamic process of the FBR is considerably influenced by the biomaterial composition. Modifications of the type of polymer, the material weight, the filament structure and the pore size are realized and have substantial effects on the in vivo biocompatibility. Moreover, modern mesh technology aims to utilize the available implants as carrier systems for bioactive drugs. Studies in animal models account for the efficiency of these drugs that aim to reduce mesh-related infections or to minimize FBR by influencing inflammation or extracellular matrix remodelling. A thorough understanding of the molecular mechanisms of FBR provides a sophisticated background for the development of new biomaterials at least as carrier systems for bioactive reagents to reduce inflammation and to improve clinical outcome.

Surgical meshes today represent a group of implants mainly used for hernia repair. Modern hernia surgery is no longer imaginable without the application of these special biomaterials leading to millions of implantations each year worldwide. Because clinical trials are insufficient to evaluate the distinct effects of modified mesh materials in regard to tissue biocompatibility and functionality, a basic understanding of the physicochemical properties of mesh materials, as well as the underlying cause for hernia formation, is essential for a rational selection of the most appropriate device. The most important properties of meshes were found to be the type of filament, tensile strength, and experimental data, which indicate that particularly the mesh's porosity is of outstanding importance.

BackgroundThe aim of this study was to analyze the early postoperative outcome of esophageal cancer treated by subtotal esophageal resection, gastric interposition and either intrathoracic or cervical anastomosis in a single center study.Methods72 patients who received either a cervical or intrathoracic anastomosis after esophageal resection for esophageal cancer were matched by age and tumor stage. Collected data from these patients were analyzed retrospectively regarding morbidity and mortality rates.ResultsAnastomotic leakage rate was significantly lower in the intrathoracic anastomosis group than in the cervical anastomosis group (4 of 36 patients (11%) vs. 11 of 36 patients (31%); p = 0.040). The hospital stay was significantly shorter in the intrathoracic anastomosis group compared to the cervical anastomosis group (14 (range 10–110) vs. 26 days (range 12 – 105); p = 0.012). Wound infection and temporary paresis of the recurrent laryngeal nerve occurred significantly more often in the cervical anastomosis group compared to the intrathoracic anastomosis group (28% vs. 0%; p = 0.002 and 11% vs. 0%; p = 0.046). The overall In-hospital mortality rate was 6% (4 of 72 patients) without any differences between the study groups.ConclusionsThe present data support the assumption that the transthoracic approach with an intrathoracic anastomosis compared to a cervical esophagogastrostomy is the safer and more beneficial procedure in patients with carcinoma of the lower and middle third of the esophagus due to a significant reduction of anastomotic leakage, wound infection, paresis of the recurrent laryngeal nerve and shorter hospital stay.

BackgroundA beneficial effect of gentamicin supplemented mesh material on tissue integration is known. To further elucidate the interaction of collagen and MMP-2 in chronic foreign body reaction and to determine the significance of the MMP-2-specific regulatory element (RE-1) that is known to mediate 80% of the MMP-2 promoter activity, the spatial and temporal transcriptional regulation of the MMP-2 gene was analyzed at the cellular level.MethodsA PVDF mesh material was surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Three different gentamicin concentrations were bound to the provided active sites of the grafted mesh surfaces (2, 5 and 8 μg/mg). 75 male transgenic MMP-2/LacZ mice harbouring the LacZ reporter gene under control of MMP-2 regulatory sequence -1241/+423, excluding the RE-1 were randomized to five groups. Bilateral of the abdominal midline one of the five different meshes was implanted subcutaneously in each animal. MMP-2 gene transcription (anti-ß-galactosidase staining) and MMP-2 protein expression (anti-MMP-2 staining) were analyzed semiquantitatively by immunohistochemistry 7, 21 and 90 days after mesh implantation. The collagen type I/III ratio was analyzed by cross polarization microscopy to determine the quality of mesh integration.ResultsThe perifilamentary ß-galactosidase expression as well as the collagen type I/III ratio increased up to the 90th day for all mesh modifications, whereas no significant changes could be observed for MMP-2 protein expression between days 21 and 90. Both the 5 and 8 μg/mg gentamicin group showed significantly reduced levels of ß-galactosidase expression and MMP-2 positive stained cells when compared to the PVDF group on day 7, 21 and 90 respectively (5 μg/mg: p < 0.05 each; 8 μg/mg: p < 0.05 each). Though the type I/III collagen ratio increased over time for all mesh modifications significant differences to the PVDF mesh were only detected for the 8 μg/mg group at all 3 time points (p < 0.05 each).ConclusionsOur current data indicate that lack of RE-1 is correlated with increased mesh induced MMP-2-gene expression for coated as well as for non-coated mesh materials. Gentamicin coating reduced MMP-2 transcription and protein expression. For the 8 μg/mg group this effect is associated with an increased type I/III collagen ratio. These findings suggest that gentamicin is beneficial for tissue integration after mesh implantation, which possibly is mediated via RE-1.

BackgroundTreatment of acute lung injury (ALI) remains an unsolved problem in intensive care medicine. Recruitment of neutrophils into the lungs, regarded as a key mechanism in progression of ALI, depends on signaling between neutrophils and platelets. Consequently we explored the effect of platelet-targeted aspirin and tirofiban treatment in endotoxin induced acute lung injuryMethodsC57Bl/6 mice were exposed to aerosolized LPS (500μg/ml) for 30min and treated with Aspirin (100μg/g bodyweight via intraperitoneal injection, 30 min before or 1 hour after LPS inhalation) or Tirofiban (0.5μg/ g bodyweight via tail vein injection 30 min before or 1 hour after LPS inhalation). The count of alveolar, interstitial, and intravascular neutrophils was assessed 4h later by flow cytometry. Lung permeability changes were assessed by FITC-dextran clearance and protein content in the BAL fluid.ResultsAspirin both before and after LPS inhalation reduced neutrophil influx into the lung and lung permeability indicating the protective role of Aspirin in ALI. Tirofiban, however, did not alter neutrophil recruitment after LPS inhalation. Release of platelet-derived chemokines CCL5 and PF4 and neutrophil extracellular traps was reduced by Aspirin but not by Tirofiban.ConclusionAspirin, but not Tirofiban reduces neutrophil recruitment and displays protective effects during endotoxin induced lung injury.

The inflammatory reaction in adhesions is not limited to the early postoperative phase. Macrophages may be fundamental in triggering adhesions, and the presence of T cells indicates an additional role of the adoptive immune system. Identification of chemokines and chemokine receptors that trigger the cellular immune response might be a potential option to minimize adhesion formation.

BackgroundIn recent years the focus on practical skills in the German curriculum of medical school has increased greatly. In this study we evaluate the value of a practical surgery course for medical students as a tool for surgical education, as a way of enhancing interest in surgical fields, and as a method of influencing medical students to subsequently choose a surgical career.MethodsThe “Feel like a surgeon”-course is an optional practical surgery course in which topographical anatomy and realistic surgical training using fresh human cadavers are combined for medical students of the RWTH Aachen University. Between 2010 and 2015 every student completed a survey before starting and after completing our course, and in 2015 a follow-up was performed. Using a standardized questionnaire, course quality, learning success and impact on post-instructional career and choice of profession was evaluated.ResultsIn total, 82 students attended our course between 2010 and 2015 and took part in the evaluation. Evaluation of the course was positive overall, with an average grade of 1.4° ± °0.50. Significant improvement of basic, as well as more complex surgical skills and theoretical knowledge was noted. Furthermore, self-confidence for patient related assignments improved as well. In the follow-up evaluation, a high level of recommendation for surgical residents was seen, as was a high influence of the course on our students’ career choice, although no significant change in career plans before and after taking the course was noted.ConclusionsOur results indicate that a practical surgical course can be a valuable tool to prepare students for a surgical residency and to improve their practical skills generally.Electronic supplementary materialThe online version of this article (doi:10.1186/s12909-016-0568-6) contains supplementary material, which is available to authorized users.