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B Klosterhalfen

Publications and source records attributed to B Klosterhalfen.

At least 19 recordsLinked to original sources
PubMed2006

Biomaterial-dependent MMP-2 expression in fibroblasts from patients with recurrent incisional hernias.

With regard to the pathogenesis of recurrent incisional hernia, an impaired connective tissue quality leading to an aberrant scarring process has been proposed. For the matrix metalloproteinase (MMP-2) a pathogenetic involvement in direct inguinal hernia development is reported. With mesh implantation as the gold standard treatment for incisional hernias, the aim of the present study was to investigate the MMP-2 expression in patients with recurrent incisional hernias with and without mesh-materials. In primary fibroblast cultures obtained from skin scars in patients with and without recurrent incisional hernias, MMP-2 synthesis and gene expression were investigated. Furthermore, MMP-2 synthesis and gene expression of fibroblasts were compared after incubation with two different mesh materials: polypropylene and absorbable polyglactin filaments. MMP-2 enzyme activity was determined by semiquantitative zymography and mRNA synthesis by quantitative RT-PCR. Both MMP-2 enzyme activity and mRNA expression were similar in hernia and control fibroblasts in vitro. In control fibroblasts mesh incubation did not significantly affect MMP-2 expression, whereas polypropylene mesh contact of fibroblasts from patients with recurrent incisional hernias led to a major decrease of MMP-2 activity and of mRNA expression. In the absence of biomaterials fibroblasts from recurrent incisional hernia, patients have no alterations of their MMP-2 synthesis compared to control fibroblasts, whereas a specific response was found after biomaterial contact hereby indicating differences in fibroblast phenotype.

Cells, Cultured↗
PubMed2005

Influence of polyglecaprone 25 (Monocryl) supplementation on the biocompatibility of a polypropylene mesh for hernia repair.

BACKGROUND: Supplementary polyglecaprone 25 (Monocryl) monofilaments were added to a lightweight pure monofilament polypropylene mesh (PP mesh) to improve intraoperative handling (PP+M mesh). This study was designed to evaluate the influence of this additional supplementation on the biocompatibility in a rodent animal model. METHODS: Two mesh materials, a composite mesh (PP+M) and the pure polypropylene variant (PP), were compared after subcutaneous implantation in a standardized rat model. Histological analysis of the inflammatory response was performed after 28, 56 and 84 days of implantation. Material absorption, inflammatory tissue reaction, fibrosis and granuloma formation were investigated, as well as the percentage of proliferating and apoptotic cells at the interface. RESULTS: Both mesh materials showed a slight foreign body reaction involving mainly macrophages and foreign body giant cells. Total absorption of the Monocryl filaments of the PP+M mesh occurred between 56 and 84 days of implantation. Both the inflammatory and the fibrotic reaction were decreased (n.s.) in the PP+M mesh group compared to the pure PP mesh. Whereas the percentage of proliferating cells showed no significant difference, the rate of apoptotic cells was significantly decreased in the PP+M mesh group over the whole implantation period. CONCLUSION: Compared to the pure polypropylene mesh, our data confirm that the use of a polypropylene mesh supplemented with absorbable Monocryl filaments is feasible without additional short-term mesh-related complications in the experimental model or negative side effects on biocompatibility.

Animals↗
PubMed2005

[High-resolution T1-weighted MR-lymphography of inguinal lymph nodes after interstitial application of Gadomer-17 in animal experiments].

PURPOSE: To evaluate the microstructural anatomy of inguinal lymph nodes in pigs after interstitial MR-lymphography with the dendritic contrast agent Gadomer-17. MATERIAL AND METHODS: High-resolution T1-weighted MR-lymphography was performed in inguinal lymph nodes of 10 domestic pigs (39 - 46 kg) after subcutaneous injection of 10 mumol/kg body weight Gadomer-17 in the hind legs of the animals. A 1.5T MR scanner and a ring-shaped surface coil were used. Two different high-resolution gradient-echo sequences with additionally reconstructed maximum-intensity projections were evaluated in a total of 20 lymph nodes. The high-resolution MR-findings were correlated with the histologic sections of the excised inguinal lymph nodes. RESULTS: Coronal T1-weighted 3D gradient-echo images (TR = 20 msec, TE = 6.1 - 8.3 msec, FA = 20 degrees ) with a slice thickness of 1 mm, a field-of-view of 120 mm and a matrix size of 256 x 256 (reconstructed to 1024 x 1024 voxels) yielding a reconstructed in-plane resolution of 117 x 117 microm (2) were best suited for the high-resolution MR lymphography of inguinal lymph nodes and enabled the differentiation of the hyperintense lymph node sinuses and hypointense lymphoid parenchyma of each lymph node (100 %). Even dilated lymphatic vessels evident in the histologic specimen were best demonstrated on the MIP images. CONCLUSION: High-resolution interstitial MR lymphography with Gadomer-17 allows the visualization of different tissue compartments of inguinal lymph nodes. This new technique is feasible on a routine 1.5T scanner and may offer potential for the detection of micrometastases in lymph nodes of cancer patients.

Animals↗
PubMed2004

Titanium coating of a polypropylene mesh for hernia repair: effect on biocompatibilty.

Titanium and its alloys are used worldwide in surgery. The favorable characteristics that make this material desirable for implantation are corrosion resistance and biocompatibility. Concerning hernia repair, a mesh modification has been developed using titanium layering of a polypropylene mesh implant, which is said to lead to an improved biocompatibility compared to commercially available mesh materials. To analyze the pure effect of titanium coating, two different mesh structures were studied using a standardized animal model. The titanium-coated monofilamentous, large porous, and lightweight mesh made of polypropylene and coated with titanium (PP+T) was compared to a pure polypropylene mesh manufactured with a similar structure and amount of material serving as a control (PP). In Sprague-Dawley rats, mesh samples were placed in a subcutaneuous position. Then 56, 84, and 182 days after mesh implantation, three animals from each group were sacrificed for morphological observations (amount of inflammatory and connective tissue formation, percentages of proliferating and apoptotic cells, percentage of macrophages). Both mesh modifications investigated showed an overall good biocompatibility. Macroscopic clinical observation after implantation of up to 182 days was uneventful. The tissue response to the PP as well as to the PP+T mesh was characterized by a moderate inflammatory tissue reaction limited to the perifilamentary region as is known for low weight, large porous, and monofilamentous mesh structures. No significant improvement of biocompatibility was found when analyzing the effect of titanium coating compared to the pure polypropylene mesh structure.

Animals↗
PubMed2004

Analysis of local complications following explantation of silicone breast implants.

A study was undertaken to analyse local complications in patients with breast implants and the total number of implant-related interventions when silicone breast implants were explanted. We studied 53 patients who had received breast implants for cosmetic augmentation or breast reconstruction following surgery for breast cancer at the time of explantation. The clinical records of all these patients were analysed, and clinical information on reason for implantation, implant properties, number and kind of implant-related interventions and reason for explantation was elicited. A complication was defined as a surgical procedure performed for any of the following reasons: capsular contracture, loss of implant integrity, haematoma or seroma, infection of the implant site, extrusion or wound dehiscence, and dissatisfaction with the result. The mean numbers of implant-related operations were 3.1 in patients who had undergone breast reconstruction and 2.3 in patients who had cosmetic augmentation (P < 0.03). We found a total of 35 complications in 28 patients, 21 patients (75%) each had one complication, five patients (18%) had two and two patients (7%) had three complications. A significantly higher incidence of early complications in patients who had undergone breast reconstruction (P < 0.03) marks the difference from complications in the cosmetic group, most of which arose after a longer time (P < 0.02). A complication analysis is presented. At the time of explantation, 78% of the patients decided to have a new implant, while 12% requested permanent removal of the implant without replacement. In the present study we saw no patients with connective tissue or other autoimmune disorders. When breast reconstruction or augmentation with silicone devices is considered, patients must be informed of the possible complications and of the potential choices in later implant-related revision surgery.

Adult↗
PubMed2003

[Ileocecal invagination due to a benign small intestine tumor. A case report].

We report a case of postoperative ileocecal invagination in a 63-year-old male. Forty-six days after esophageal resection and gastric tube reconstruction with cervical anastomosis for an esophageal carcinoma, the patient suffered from colicky pain in the right abdomen. The diagnostics showed an ileocecal invagination up to the right flexure of the colon. The invagination was based on a leiomyoma of the terminal ileum. Because of necrosis of the mucous membrane, an ileocecal resection with ileoascendostomy could not be avoided. We discuss this case on the basis of the existing literature.

Humans↗
PubMed2003

Caecal-diverticulitis: a rare differential diagnosis for right-sided lower abdominal pain.

OBJECTIVE: There are several differential diagnoses for acute abdominal discomfort with pain referred to the right lower quadrant region. The objective of this report is to outline our experience with diverticulitis of the caecum, which is a rare condition that is particularly difficult to diagnose correctly pre-operatively. METHODS: A retrospective analysis of acute diverticulitis of the caecum was performed over the period from January 1992 to December 2000 within the Surgical Department of the RWTH Aachen, Germany. The progress of each patient was assessed by interviewing the patient and by telephone contact with the patient's general practitioner. RESULTS: Seven patients with isolated infective diverticulitis of the caecum were encountered in the course of this study. In five of these cases, the pre-operative diagnosis was either unclear or incorrect. Four patients underwent surgery for suspected appendicitis. In one patient, the diverticulitis was diagnosed during laparoscopic surgery undertaken for presumed adnexal disease. Intestinal continuity was restored in all cases. The postoperative course was uneventful. CONCLUSIONS: Right-sided caecal diverticulitis is rare in comparison to diverticulitis of the sigmoid or descending colon. Nevertheless, it should be actively considered in the differential diagnosis of patients with acute tenderness in the right lower abdominal region.

Abdominal Pain↗
PubMed2002

Functional and morphological evaluation of a low-weight, monofilament polypropylene mesh for hernia repair.

With more than 1 million implantations per year worldwide, mesh repair has become a standard procedure for the treatment of hernias. Apart from various technical problems, the type of material has been proven to be of considerable importance for the functional and histological outcome, particularly for long-term implantation. Whereas the advantageous application of low-weight, large-pore meshes based on multifilaments can be stated without doubt, it is still open whether similar results can be achieved on the basis of pure monofilaments. In the present study, a low-weight polypropylene mesh (LW) made purely of monofilaments was compared to a common heavy-weight polypropylene mesh (HW) in regard to the functional consequences and the tissue response. After implantation in rats as an inlay for 3--90 days, the abdominal-wall mobility of the implant region was recorded by 3D stereography, and the tensile strength of both the suture zone and the mesh was measured. The morphometry of the histological reaction in regard to the inflammatory infiltrate, the connective tissue, the number of granulocytes, macrophages, and fibroblasts served to reflect the tissue response. As parameters for the remodeling process at the interface the cellular activation was evaluated by TUNEL (DNA-strand breaks or apoptosis, respectively), Ki 67 (cell proliferation), and HSP 70 (cell stress). The measured tensile strength of the LW mesh confirmed a sufficient strength of the material-reduced mesh modification. After implantation the consecutive impairment of the abdominal-wall mobility was reduced compared to the HW mesh, concomitant to the reduced fibrotic level at the interface. At the end of the observation period the foreign-body reaction was significantly lowered for the LW mesh, almost reaching physiological values. In conclusion, these data confirm the improved biocompatibility of material-reduced mesh implants.

Abdominal Wall↗
PubMed2002

Do multifilament alloplastic meshes increase the infection rate? Analysis of the polymeric surface, the bacteria adherence, and the in vivo consequences in a rat model.

Within the last decade hernia surgery has changed from suture repair to mesh repair. Biomaterials, and multifilaments in particular, are thought to increase the risk of infection. Therefore, the aim of this study was to study the influence of the presence of either a monofilament or a multifilament mesh material on the bacterial infection risk. The filament surface of a monofilament and a multifilament mesh were calculated on the basis of a theoretical model. The adherence of Staphylococcus aureus was measured in vitro by fluorescence analysis. Additionally, the two mesh materials (8-mm platelets) were implanted subcutaneously in Sprague-Dawley rats with daily surveillance for clinical signs of infection. After 7 days the meshes were explanted for histological and microbiological analysis. Calculations of the mesh surface area revealed a higher level for the multifilament mesh. The extent of adherent bacteria corresponded to the estimated filament surface in vitro. In vivo, the implantation of meshes in the presence of 5 x 10(6) S. aureus did not show an increased infection rate in rats with either monofilament or multifilament material, compared to the control groups (mesh implantation without S. aureus contamination). However, after 7 days bacteria were still detectable in the majority of the implantation sites, and a clinically inapparent intensification of local inflammation and fibrosis was induced. The increased surface area of a multifilament meshes promotes the persistence of bacteria in the implant bed, though this alone is not sufficient to create a clinically apparent infection. This might explain the development of mesh-related infections after a delay of several months or even years. In vivo, the adherence of bacteria to the implant material depends on the surface area, which favors the use of monofilament materials.

Animals↗
PubMed2002

Impact of polymer pore size on the interface scar formation in a rat model.

BACKGROUND: The surgical therapy of hernias is increasingly based on reinforcement with alloplastic material, in particular surgical meshes. The biological response to these foreign bodies largely depends on the selected material and its structure. In comparison to the physiological scar process following a simple abdominal wall incision, the chronic inflammation at the interface to the polymers lead to specific morphological alterations. MATERIALS AND METHODS: In the present study two meshes with different pore sizes were implanted into rats: a heavy-weight and small-pore-sized mesh (hw-mesh) made of nonabsorbable polypropylene monofilaments and a low-weight large-pore-sized mesh consisting of polypropylene and of absorbable polyglactin multifilaments (lw-mesh). A suture repair of a laparotomy served as control. After 7, 14, 21, and 90 days the mesh area was analyzed with regard to tissue and cellular response. RESULTS: Over the whole observation period morphometric analysis indicated an improved integration of the lw-mesh with reduction of both inflammation and fibrosis, whereas the hw-mesh induced an intense chronic inflammation concomitant with an intensified bridging scar reaction. On the cellular level these findings correspond to an elevated cell turnover, characterized by increased rates of apoptotic and proliferating cells. In contrast, the tissue reaction to the lw-mesh achieved levels almost similar to those of the physiological scaring process in the control group. CONCLUSION: In conclusion, the present data confirm the development of a chronic inflammatory foreign body reaction at the interface to both hw-meshes and lw-meshes; however, the use of lw-meshes showed superior tissue integration. With regard to the quite similar polymer surface the pore size appears to be of major importance in tissue reaction and for the biocompatibility of mesh structures.

Animals↗
PubMed2002

A 24-h pneumoperitoneum leads to multiple organ impairment in a porcine model.

BACKGROUND: An intra-abdominal pressure (IAP) of 15 mm Hg reduces intestinal organ perfusion in humans and animals, but it is unknown whether this results in organ damage. The purpose of this study was to evaluate if an IAP of 15 mm Hg lasting for 24 h in a porcine model will lead to morphologic impairment of intestinal and adjacent organs. METHODS: We examined 12 intubated and anesthetized domestic pigs (51.8 +/- 4.4 kg). Using CO2 pneumoperitoneum, the IAP was raised to 15 mm Hg (study group, n = 6) for an investigation period of 24 h. In the control group, the IAP remained unchanged. Investigated parameters were cardiac output (CO), peak inspiratory pressure (PIP), and urine output (UO), as well as serum creatinine, alanine aminotransferase (ALT), lactate, lipase, and alkaline phosphatase (AP). Additionally, histopathological examinations were performed.Results. In comparison to the control, CO did not change, while UO decreased significantly by 59% and PIP increased significantly to more than 30 mbar. Serum ALT and AP increased significantly while there was no change in creatinine, lactate, and lipase. Histopathologically, low-grade liver necrosis (12% of liver lobuli), low-grade proximal tubular epithelial necrosis, and low bowel mucosal damage were observed.Conclusion. In this porcine model, an IAP of 15 mm Hg lasting for 24 h was found to result in functional and morphologic impairment of lungs, liver, kidneys, and bowel. These results imply that a prolonged IAP of 15 mm Hg predisposes to multiorgan dysfunction and that a safe duration of increased IAP still has to be determined.

Alkaline Phosphatase↗
PubMed2002

[Weakly malignant leiomyosarcoma of the inferior vena cava. A case report].

Primary vascular leiomyosarcomas of the great vessels are rare and the most common localization is the inferior vena cava. Due to nonspecific clinical signs, diagnosis is often made during operation or autopsy. At present, a radical tumor resection is the first choice of treatment. This is a case report of a 49-year-old woman who suffered from abdominal pain for 10 years because of a weakly malignant leiomyosarcoma of the inferior vena cava. A radical tumor resection and reconstruction with a prosthetic vascular graft were performed. Diagnosis, therapy, and prognosis are discussed.

Blood Vessel Prosthesis Implantation↗
PubMed2002

A simple new method to calculate small intestine absorptive surface in the rat.

The rat is an established model for studying intestinal adaptations following abdominal surgery. In the study of functional and morphological adaptations of the small intestine, it is helpful to estimate the mucosal surface area. In order to simplify measurements and calculation we developed a new mathematical model for calculation of the mucosal surface area on histological sections. In contrast to other methods, it requires only cross-sections of small intestine and includes the measurement of only three histological parameters: length and width of villus and width of crypt. The new approach was compared with the most commonly used procedures, the Harris and the Fisher-Parsons methods, under experimental conditions. An animal study including single-pass perfusion, fixation, staining and subsequent histomorphometry of jejunum and ileum using these different methods was performed. The new method showed the least work and presented no significant differences compared with the precise Harris method. In conclusion, the method described is an adequate tool to estimate the mucosal surface area with less work and with comparable results to established methods. The less-complex method may be a valuable tool in experimental research of small intestine adaptations in rats.

Animals↗
PubMed2002

PVDF as a new polymer for the construction of surgical meshes.

Abdominal hernia repair is the most frequently performed operation in surgery. Mostly due to lowered recurrence rates mesh repairs in hernia surgery have become an integral component despite increasing mesh-related complications. Current available mesh prosthesis are made of polypropylene (PP). polyethylene-terephtalat or polytetrafluorethylene. though all of them reveal some disadvantages. The introduction of new materials seems to be advisable. Caused by supposed advantageous textile properties and tissue response two mesh modifications made of polyvinylidene fluoride (PVDF) for abdominal hernia repair were developed. In the present study the PVDF meshes were compared to a common heavy weight PP-mesh (Prolene) in regard to functional consequences and morphological tissue response. After implantation in rats as inlay for 3, 14, 21, 42 and 90 days abdominal wall mobility was recorded by three-dimensional photogrammetry. Tensile strength of the suture zone and the mesh itself were determined. Explanted tissue samples have been investigated for their histological reaction in regard to the inflammatory infiltrate. vascularisation, connective and fat tissue ingrowth. Number of granulocytes, macrophages, fibroblasts, lymphocytes and foreign giant body cells have been evaluated to reflect quality of tissue response. The cellular response was grasped by measurement of DNA strand breaks and apoptosis (TUNEL), proliferation (Ki67) and cell stress (HSP70). Analyzing the results confirmed that construction of hernia meshes made of PVDF could be an advantageous alternative to the commonly used materials due to an improved biostability. lowered bending stiffness and a minimum tissue response.

Animals↗
PubMed2002

Influence of implantation interval on the long-term biocompatibility of surgical mesh.

BACKGROUND: The aim was to study the long-term tissue response to polypropylene mesh. METHODS: This was a retrieval study that investigated 76 polypropylene meshes with a median implantation interval of 18 (range 2-180) months. Mesh was explanted following hernia recurrence, infection or pain. The median implantation interval was 20 (range 4-180) months in the recurrence group, 30 (range 5-48) months in the pain group and 10 (range 2-56) months in the infection group (P < 0.05, infection versus pain or recurrence). The inflammatory response was determined by immunohistochemistry of macrophages (CD68), polymorphonuclear granulocytes (CD15) and T and B lymphocytes (CD3 and CD20). The cell turnover within the interface mesh fibre-recipient tissue was measured by TUNEL for apoptosis or DNA strand breaks, Ki67 for cell proliferation and heat-shock protein (HSP) 70 for cell stress. RESULTS: With the exception of HSP-70, levels of all variables decreased over time. Sex, age, type of previous operation or location of the mesh did not have a significant influence. CONCLUSION: Long-term incorporated polypropylene mesh in humans has a more favourable tissue response with increasing implantation interval.

Adult↗
PubMed2002

Uptake of cis-4-[18 F]fluoro-L-proline in scar formation: a marker of collagen synthesis?

Excessive scar formation is accompanied by abnormal collagen synthesis. The feasibility of monitoring collagen synthesis in vivo with no-carrier-added cis-4[18F]fluoro-L-proline (cis-FPro) was evaluated in an animal model with scar formation induced by implanted meshes. The abdominal wall of rats was replaced by alloplastic meshes. At days 3, 7, 14, 21 and 90 after implantation, the uptake of cis-FPro at 4 h post-injection was determined for resected samples of the mesh and normal tissues. The highest uptake was found in the kidneys (1.73+/-0.47%ID/g) followed by the liver (0.59+/-0.19%ID/g). The meshes showed the maximum uptake at day 3 (0.20+/-0.07%ID/g) with a decrease to 0.10+/-0.03%ID/g at day 90 (P<0.001). After 3 days no connective tissue was shown by histopathological morphometric analysis. The maximum partial volume (PV%) of connective tissue was 43+/-14 PV% 90 days after implantation. The maximum levels of granulocytes and inflammatory infiltrate were found at day 3 with minimal levels at day 90, paralleling the course of cis-FPro uptake. In conclusion, the uptake of cis-FPro at 4 h post-injection is not related to the content of connective tissue. Cis-FPro radiolabelled with 18F appears not to be a suitable radiopharmaceutical for in vivo monitoring of collagen synthesis in scar formation.

Abdominal Wall↗
PubMed2002

[Pathology of implants].

Progress in the surgery of implants and biomaterials can be accomplished by: 1. Painstakingly analysing and registering of defaulting implants after explantation within a "National Registry of Implant Pathology". 2. Development of a DNA-microarray named "Implantat/Chronic Wound" in order to discover the differential transcriptional activities of cells brought into contact with different foreign surfaces. 3. Predictive cell-engineering combined with custom-made implant surfaces with the aim of optimal patient care.

Cells, Cultured↗