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K Junge

Publications and source records attributed to K Junge.

61 records · Page 4Linked to original sources
PubMedDate not supplied

Influence of mesh materials on collagen deposition in a rat model.

Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the expression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein (microg/mg) showed significant differences comparing different mesh materials (sham controls 38.44 +/- 16.33 microg/mg, PE 68.5 +/- 23.8 microg/mg, PP 101.6 +/- 32.3 microg/mg, PG 49.6 +/- 11.6 microg/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated (r =.95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material.

Animals↗
PubMedDate not supplied

Influence of pneumoperitoneum on small bowel anastomoses: a histological analysis in the rat model.

Laparoscopic techniques are increasingly applied for the treatment of diverse gastrointestinal diseases. With regard to reports of a pronounced decrease of intra-abdominal blood flow with increasing intra-abdominal pressure, the present study investigates the impact of pressure and gas type on ischemia in small bowel anastomoses in the rat model. Laparotomy and ileoileal anastomosis were performed in 39 male Sprague-Dawley rats. A CO2 or helium pneumoperitoneum of 3 mm Hg or of 6 mm Hg was maintained before and after anastomoses. Rats in the control group received no pneumoperitoneum. Animals were sacrificed after 5 d, and the anastomotic region was explanted for subsequent histopathological examinations. In hematoxylin and eosin (HE)-stained sections, the Chiu score, villi configuration, and number of goblet cells were analyzed. Proliferation (Ki67) and expression of a matrix metalloproteinase (MMP-8) were examined by immunohistochemistry. Mucosal damage according to the scoring system by Chiu, the number of goblet cells, the villus length, the proliferation (Ki67), and the submucosal expression of MMP-8 was similar in all groups. Our results suggest that within a certain range of pressures and time, laparoscopic assisted surgery using CO2 pneumoperitoneum can be performed safely. Helium gas offers no advantages over CO2.

Anastomosis, Surgical↗
PubMedDate not supplied

Mesh implants in hernia repair. Inflammatory cell response in a rat model.

BACKGROUND: In the reinforcement of the abdominal wall with mesh implants, various complications including hernia recurrence, abdominal pain, seroma formation and infection are discussed to depend on the biocompatibility of the alloplastic prosthesis. Particularly macrophages, T-cells and mast cells have been shown to play a major role in the inflammatory response to biomaterials. To approach biocompatibility of surgical meshes we therefore examined the infiltrate of these cells as well as the proliferation rate in response to different clinically applied materials. MATERIALS AND METHODS: Three mesh materials (polypropylene: PP, Prolene; polyethylene terephthalate: PET, Mersilene, and polypropylene/polyglactin: PP + PG, Vypro) were compared after inlay implantation in a standardized rodent animal model. A suture-closed laparotomy served as control. After 7 and 90 days of implantation, histochemical analysis of the inflammatory response to all biomaterials was performed: macrophages (ED3), T-cells (CD3), proliferating cells (PCNA) and mast cells (Giemsa) were investigated. RESULTS: In all groups a persisting T-cell response was observed. Colonization of the interface with macrophages showed a pronounced reduction in the PP + PG-mesh group. Infiltration of mast cells at the tissue graft interface showed a time-dependent decrease in the PET- and PP + PG-mesh groups, whereas in contrast, index of mast cells increased in the PP-mesh group. At both time points, indices of proliferation were highest in the PP-mesh group. CONCLUSION: The present data confirm the development of a biomaterial-dependent chronic inflammatory response to surgical meshes with macrophages as the predominant cell type. Further research on the recruitment of inflammatory cells and in particular on the role of mast cells and their granular products should be encouraged.

Animals↗
PubMedDate not supplied

Vypro II mesh in hernia repair: impact of polyglactin on long-term incorporation in rats.

BACKGROUND: To the Vypro II mesh, a large-pore-sized multifilamentous polypropylene mesh for hernia repair, supplementary polyglactin 910 multifilaments were added to improve intraoperative handling. As it has been suggested that polyglactin induces fibroplastic reactions and wound complications, this study was designed to evaluate the long-term tissue reaction to polyglactin in the Vypro II mesh. MATERIALS AND METHODS: Two mesh materials, the Vypro II composite mesh (PP + PG) and the pure polypropylene variant (PP), were compared after inlay implantation in a standardized rodent animal model. After 14, 28, 42, 56, 84 and 112 days of implantation, histological analysis of the inflammatory response was performed: material absorption, inflammatory tissue reaction, fibrosis and granuloma formation were investigated. RESULTS: Total absorption of polyglactin filaments of the Vypro II mesh occurred between 56 and 84 days of implantation. Both the inflammatory and the fibrotic reaction were initially increased in the PP + PG mesh group. These differences disappeared in the following implantation period. After 112 days, inflammation was even less pronounced in the PP + PG mesh group. CONCLUSION: The present data confirm a short-term polyglactin-induced increase in inflammation and fibrosis around implanted Vypro II meshes in rats. With regard to the long-term tissue response, even an anti-inflammatory property of polyglactin multifilaments in low-weight and large-pored polypropylene meshes cannot be ruled out.

Absorption↗
PubMedDate not supplied

Persistent extracellular matrix remodelling at the interface to polymers used for hernia repair.

On the one hand, recurrence rates and postoperative complications following hernia repair are supposed to be influenced by the kind of mesh material used. On the other hand, an impaired collagen metabolism and cleavage within connective tissue has been suggested as decisive factor in the pathogenesis of recurrent hernia formation. The aim of our study was, therefore, to analyze the impact of commonly used mesh materials on quality of collagen deposition, expression of collagenases (matrix metalloproteinases; MMP-1/MMP-13), and specific tissue inhibitors of MMPs (TIMPs) in an animal study. Four different mesh materials were used (Prolene = polypropylene, Mersilene = polyester, and Vypro and Vypro II = combinations of polypropylene and polyglactin) and implanted as abdominal wall replacement in 60 male Wistar rats. Mesh samples were explanted after 3, 21, and 90 days and investigated using immunohistochemistry (expression of MMP-1/MMP-13 and TIMP-1) and cross-polarization microscopy (percentage of collagen type III to overall collagen). Besides an insufficient collagen composition with an increased percentage of collagen type III, we found a complex expression of collagenases and their inhibitors combined with a persistent chronic foreign-body reaction even 90 days after implantation. Except for TIMP-1 expression, which was significantly related to a lowered amount of inflammatory (r = -0.980, p = 0.02) and connective tissue formation (r = -0.951, p = 0.049), there was no relation to the expression of collagenases (MMP-1/MMP-13) with regard to the amount of inflammatory and connective tissue formation despite partly significant differences between implanted polymers.

Animals↗
PubMedDate not supplied

Peritoneal release of TNFalpha and IL-6 after elective colorectal surgery and anastomotic leakage.

The evaluation of postoperative peritoneal drainage fluid tumor necrosis factor (TNF)alpha and interleukin (IL)-6 was studied prospectively over a 7-day period in 25 patients operated on for neoplastic colorectal diseases. In 22 cases, colon or rectum carcinoma was the reason for surgery, and in 3 patients resection was performed because of colonic adenoma. All patients received either an end-to-end colo-colonic or colorectal anastomosis. Of this group, 22 patients were free of complications defined as uneventful postoperative course without any signs of anastomotic leakage until the 14th postoperative day. All of these patients showed a significant rise in peritoneal TNFalpha with maximum on the 7th day during the study period (p <.05). In contrast, peritoneal IL-6 levels remained constant without significant change in time (p >.05). Three patients underwent relaparotomy because of anastomotic leakage. In these patients, peritoneal TNFalpha concentrations showed a rise until the day of operative confirmation of anastomotic leakage. This rise preceded the day of operative confirmation by at least 1 day but did not change significantly in time (p =.59). Peritoneal IL-6 concentrations in patients with anastomotic leakage remained constant and also did not change significantly in time (p =.21). After elective colorectal surgery, neither postoperative abdominal drainage fluid TNFalpha nor IL-6 monitoring is helpful to decide on the need for revision in patients with anastomotic leakage.

Adult↗