Our current data suggest that even in the long-term course after six months and despite a higher effective surface of the PVDF samples it showed a smaller foreign body granuloma than with PP whereas the cellular response was similar.

Based on our findings, surgical delay in the case of appendicitis and operation at night did not increase the risk for postoperative complications. However, the mean waiting time was less than 12 h and patients aged 70 years or older were at a higher risk for postoperative complications. Furthermore, for the subgroup of patients with complicated appendicitis, the time interval to surgery had a significant influence on the occurrence of postoperative complications. Therefore, the contemporary operation depending on the clinical symptoms and patient age remains our recommendation.

BackgroundEvery surgical suture compresses the enclosed tissue with a tension that depends from the knotting force and the resistance of the tissue. The aim of this study was to identify the dynamic change of applied suture tension with regard to the tissue specific cutting reaction.MethodsIn rabbits we placed single polypropylene sutures (3/0) in skin, muscle, liver, stomach and small intestine. Six measurements for each single organ were determined by tension sensors for 60 minutes. We collected tissue specimens to analyse the connective tissue stability by measuring the collagen/protein content.ResultsWe identified three phases in the process of suture loosening. The initial rapid loss of the first phase lasts only one minute. It can be regarded as cutting through damage of the tissue. The percentage of lost tension is closely related to the collagen content of the tissue (r = -0.424; p = 0.016). The second phase is characterized by a slower decrease of suture tension, reflecting a tissue specific plastic deformation. Phase 3 is characterized by a plateau representing the remaining structural stability of the tissue. The ratio of remaining tension to initial tension of phase 1 is closely related to the collagen content of the tissue (r = 0.392; p = 0.026).ConclusionsKnotted non-elastic monofilament sutures rapidly loose tension. The initial phase of high tension may be narrowed by reduction of the surgeons' initial force of the sutures' elasticity to those of the tissue. Further studies have to confirm, whether reduced tissue compression and less local damage permits improved wound healing.

To reduce infection rates after mesh implantation antibiotic-coated meshes were designed. The aim of the study was to analyze biocompatibility and in vitro efficiency of a modified gentamicin-supplemented polyvinylidenfluoride mesh. Twenty rats were randomized to two groups (PVDF group and Genta group). Mesh material was implanted subcutaneously. Blood samples were taken to determine the gentamicin serum concentration. Seven and 90 days after mesh implantation, animals were euthanized. The inflammatory tissue response was characterized by analyzing the foreign body granuloma. Cellular immune response was analyzed by immunohistochemical investigations. The collagen type I/III ratio was estimated by crosspolarization microscopy. In vitro agar diffusion test, suspension test, and gentamicin release were characterized. Agar diffusion and suspension test showed efficient antibiotic effects of the mesh in vitro. Serum concentrations of gentamicin showed a peak value 1 h postoperatively with a decline within the next day. The total size of the granuloma was significantly smaller in the Genta group compared to the PVDF group at both points of time. Except of a short period of increased expression of CD68 in the Genta group after 7 days, no further difference was found analyzing cellular immune response. The collagen type I/III ratio was widely constant analyzing the two mesh types without significant differences comparing both mesh materials. A significantly decreased foreign body granuloma formation compared to the pure PVDF mesh group was found. In vitro analysis showed efficient antibiotic effects of the Gentamicin supplementation compared to the pure PVDF mesh.

This study has shown that colonic wall changes and enteric neuropathy seem to play a role in the pathogenesis of colonic diverticulosis. None of our results suggest a predisposition for a complicated diverticular disease. Furthermore, the presence of an anatomic sphincter at the rectosigmoid junction could not be detected.

Polypropylene meshes are standard for hernia repair. Matrix metalloproteinases play a central role in inflammation. To reduce the inflammatory response and improve remodelling with an associated reduction of hernia recurrence, we modified polypropylene meshes by nanofibre coating and saturation with the broad-spectrum matrix metalloproteinase inhibitor GM6001. The aim was to modulate the inflammatory reaction, increase collagen deposition and improve mesh biointegration. Polypropylene meshes were surface-modified with star-configured NCO-sP(EO -stat-PO) and covered with electrospun nanofibres (polypropylene-nano) and GM6001 (polypropylene-nano-GM). In a hernia model, defects were reconstructed with one of the meshes. Inflammation, neovascularization, bio-integration, proliferation and apoptosis were assessed histologically, collagen content and gelatinases biochemically. Mesh surface modification resulted in higher inflammatory response compared to polypropylene. Pro-inflammatory matrix metalloproteinase-9 paralleled findings while GM6001 reduced matrix metalloproteinase-9 significantly. Significantly increased matrix metalloproteinase-2 beneficial for remodelling was noted with polypropylene-nano-meshes. Increased vascular endothelial growth factor, neo-vascularization and collagen content were measured in polypropylene-nano-meshes compared to polypropylene. GM6001 significantly reduced myofibroblasts. This effect ended after d14 due to engineering limitations with release of maximal GM6001 loading. Nanofibre-coating of polypropylene-meshes confers better tissue vascularization to the cost of increased inflammation. This phenomenon can be only partially compensated by GM6001. Future research will enable higher GM6001 uptake in nano-coated meshes and may alter mesh biointegration in a more pronounced way.

The risk for SSI is lower in patients with PSA in comparison to patients with PLC. In order to diminish SSI we recommend performing a PSA in patients with loop ileostomy reversal.

Background: In order to allow inflammatory response modification and ultimately improvement in tissue remodeling, we developed a new surface modification for meshes that will serve as a carrier for other substances. Biocompatibility is tested in an animal model. Methods: The animal model for diaphragmatic hernia repair was established in prior studies. Meshes were surface modified with star-configured PEO (polyethylene oxide)-based molecules [sP(EO-stat-PO)]. An electrospun nanoweb of short-term absorbable PLGA (polylactide-co-glycolide) with integrated sP(EO-stat-PO) molecules was applied onto the modified meshes. This coating also served as aerial sealing of the diaphragm. A final layer of hydrogel was applied to the product. Adhesive properties, defect size and mesh shrinkage were determined, and histological and immunohistochemical investigations performed after 4 months. Results: The mean defect size decreased markedly in both modified mesh groups. Histologically and with regard to apoptosis and proliferation rate, smooth muscle cells, collagen I/III ratio and macrophage count, no statistically significant difference was seen between the 3 mesh groups. Conclusions: In this proof-of-principle investigation, we demonstrate good biocompatibility for this surface-modified mesh compared to a standard polypropylene-based mesh. This new coating represents a promising tool as a carrier for bioactive substances in the near future.