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Biomedical subjects

U Klinge

Publications and source records attributed to U Klinge.

At least 19 recordsLinked to original sources

Gas-related impact of pneumoperitoneum on systemic wound healing.

INTRODUCTION: The aim of the present study was to investigate the gas-dependent effects of pneumoperitoneum on wound healing distant from the abdomen. MATERIALS AND METHODS: Dorsal skin incisions were performed in 54 male Sprague-Dawley rats. A CO(2) or a helium pneumoperitoneum of 3 mmHg was maintained before, with an overall duration of 30 min (each n = 18). Rats in the control group received laparotomy only (n = 18). Animals were killed after 5 and 10 days. The infiltration of macrophages (CD 68), expression of matrix metalloproteinase 13 (MMP-13) and collagen I/III ratios were analysed in the dorsal skin wounds. RESULTS: Both after 5 and 10 days, infiltration of macrophages and expression of MMP-13 were greatest after helium pneumoperitoneum. After 5 days, collagen I/III ratio was significantly increased in the helium group. After 10 days, collagen I/III ratio was lowest in the CO(2) group. CONCLUSION: Our results suggest beneficial effects on systemic wound healing for helium pneumoperitoneum as compared to CO(2).

Animals↗

Different matrix micro-environments in colon cancer and diverticular disease.

BACKGROUND AND AIMS: The extracellular matrix and the interactive signalling between its components are thought to play a pivotal role for tumour development and metastasis formation. An altered matrix composition as potential underlying pathology for the development of colorectal cancer was hypothesized. METHODS: In a retrospective study of patients with colon cancer, the extracellular matrix in tumour-free bowel specimen was investigated in comparison with non-infected bowel specimen from patients operated on for colonic diverticulosis. The following matrix parameters with known associations to tumour formation, cell proliferation, invasion and metastasis were analysed by immunohistochemistry and quantified by a scoring system: VEGF, TGF-beta, ESDN, CD117, c-erb-2, cyclin D1, p53, p27, COX-2, YB-1, collagen I/III, MMP-13, PAI and uPAR. Expression profiles and correlations were calculated. RESULTS: The comparison of the two groups revealed a significantly decreased immunostaining for CD117 and TGF-beta in the cancer group (8.5+/-2.6 vs 10.3+/-2,1 and 4.9+/-1.5 vs 8.1+/-3, respectively), whereas PAI scores were significantly higher than in patients with diverticular disease (8.1+/-1.6 vs 6.2+/-0.9). Overall correlation patterns of matrix parameters indicated pronounced differences between tumour-free tissue in cancer patients compared with patients with diverticular disease. CONCLUSIONS: Our results indicate distinct differences in the colonic tissue architecture between cancer patients and patients with diverticulitis that support the notion of an altered matrix composition predisposing to the development of colon cancer.

Collagen Type I↗

Risk factors related to recurrence in inguinal hernia repair: a retrospective analysis.

The aim of this study was to analyze and evaluate the long-term recurrence rate and risk factors for inguinal hernia recurrence in patients treated by the Shouldice suture repair. A total of 293 hernias treated by Shouldice suture technique in 1992 were studied retrospectively. After a 10-year follow-up, 15 potential risk factors for recurrence were assessed in 142 patients undergoing 171 Shouldice repairs. Recurrent hernias showed a significantly higher (22.0%) recurrence rate than primary inguinal hernias (7.7%). Furthermore, an age of more than 50 years, smoking, and the presence of two or more similarly affected relatives were found to be independent risk factors for recurrence. The present study underlines the importance of patient-related risk factors for the development of a recurrent inguinal hernia. Patients at risk should preoperatively be identified in order to improve treatment by, for example, the application of mesh techniques.

Adolescent↗

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↗

[Management of recurrent inguinal hernia after previous mesh repair: a challenge].

INTRODUCTION: Since the use of prosthetic mesh for the surgical repair of inguinal hernias has become increasingly popular, mesh material introduced during a previous operation is being detected in a growing number of patients undergoing surgery for recurrent hernia. This applies to at least 10% of recurrences. Needed is a therapeutic algorithm for the surgical management of recurrent hernias after previous mesh repair. MATERIAL AND METHODS: A total of 672 recurrent hernia repairs performed in hospitals in the German cities Aachen and Koblenz were analysed in order to review clinical practice. In 92 patients (13.7%) who underwent surgery for recurrent hernia, mesh had been used in the previous hernia repairs. Attention was focused on the location of the recurrence in relation to the site of mesh implantation and on the advantages and disadvantages of the various surgical procedures for repairing recurrent hernias. Re-examination was performed with a mean follow-up of 3 years. RESULTS: Surgeons mostly decided during operation which procedure to use. A transinguinal approach was preferred for patients presenting with recurrent hernia and pain, and mesh material introduced during a previous operation was then explanted. In the case of multiple recurrences, a minimal direct suture repair was used for small defects or a preperitoneal approach for inserting a new, large mesh. The majority of recurrences were medial or suprapubic, especially those occurring after a Lichtenstein repair. After re-examining 87 of 92 patients, nine recurrences (10.3%) were found. Mesh-free suturing methods were affected most frequently. Moderate complaints were reported by 39.1%, and 4.6% suffered from medical chronic pain. CONCLUSION: The surgical management of recurrent hernias after previous mesh repair is a particular challenge for surgeons. We introduce a therapeutic algorithm for recurrent hernia surgery after previous mesh implantation based on analysis of clinical practice.

Adult↗

Improved abdominal wall wound healing by helium pneumoperitoneum.

BACKGROUND: Despite widespread use of the endoscopic technique in the treatment of inguinal and incisional hernias, knowledge about its impact on abdominal wall wound healing is rare. Questions remain regarding the risk of port-site hernias and hernia recurrence. The current study investigated the gas-dependent effects of pneumoperitoneum on laparotomy wound healing. METHODS: Laparotomy was performed in 54 male Sprague-Dawley rats. A carbon dioxide (n = 18) or helium (n = 18) pneumoperitoneum of 3 mmHg was maintained before and after laparotomy, with an overall duration of 30 min. The rats in the control group (n = 18) received no pneumoperitoneum. The animals were killed after 5 and 10 days, and the abdominal wall was explanted for subsequent histopathologic examinations of the laparotomy wound. The granuloma formation in hematoxylin and eosin-stained sections was analyzed. Infiltration of macrophages (CD68) and expression of matrix metalloproteinases (MMP-8 and MMP-13) were examined by immunohistochemistry. The collagen type 1 to type 3 ratio was investigated by cross-polarization microscopy after Sirius Red staining. RESULTS: After 5 and 10 days, the percentages of CD68-positive cells, granuloma formation, and expression of MMP-8 did not differ between the groups. In contrast, after both 5 and 10 days, the expression of MMP-13 and the collagen 1 to 3 ratio were significantly higher after helium pneumoperitoneum than in the control animals. CONCLUSION: The results suggest that helium pneumoperitoneum may ameliorate wound healing within the abdominal wall and could therefore represent a beneficial gas for endoscopic hernia repair.

Abdominal Wall↗

Are collagens the culprits in the development of incisional and inguinal hernia disease?

Incidence curves for the development of inguinal hernia disease and recurrences thereof exhibit a linear rise over the years and therefore suggest multi-factorial underlying causes. Several studies have revealed marked changes in the abundance and composition of interstitial collagens in patients with (recurrent) hernia diseases, adult groin hernia and incisional hernia. These observations led to the hypothesis that hernia formation and the recurrence of incisional hernia may be explained by disordered tissue renewal and by abnormal wound healing, respectively. Interstitial collagens, owing to their long half-lives and biomechanical strength, are most likely critical components of the biological system of tissue remodelling. An overview of the literature is provided, and the consequences for surgical practice are discussed.

Collagen↗

Modification of collagen formation using supplemented mesh materials.

BACKGROUND: Formation of recurrent inguinal and incisional hernia shows an underlying defect in the wound healing process. Even following mesh repair an altered collagen formation and insufficient mesh integration has been found as main reason for recurrences. Therefore the development of bioactive mesh materials to achieve a local modification of the scar formation to improve patients outcome is advisable. METHODS: Thirty-six male Wistar rats were used within this study. A Mersilene (R) mesh sample was implanted after midline skin incision and subcutaneous preparation. Before implantation mesh samples were incubated for 30 minutes with either one of the following agents: doxycycline, TGF-beta 3, zinc-hydrogeneaspartate, ascorbic acid, hyaluronic acid. Incubation with a physiologic 0.9 % NaCl solution served as control. Seven and 90 days after mesh implantation 3 animals from each group (n = 6) were sacrificed for morphological observations. Collagen quantity and quality was analyzed measuring the collagen/protein as well as the collagen type I/III ratio. RESULTS: Following an implantation interval of 90 days supplementation with doxycycline (39.3 +/- 7.0 microg/mg) and hyaluronic acid (34.4 +/- 5.8 microg/mg) were found to have a significantly increased collagen/protein ratio compared to implantation of the pure Mersilene (R) mesh samples (28.3 +/- 1.9 microg/mg). Furthermore, an overall increase of the collagen type I/III ratio was found in all groups indicating scar maturation over time. However, no significant differences were found after 7 and 90 days of implantation comparing collagen type I/III ratio of supplemented mesh samples and control group. CONCLUSIONS: In summary, we found an influence of supplemented mesh materials on collagen deposition. However, the investigated bioactive agents with reported influence on wound healing were not associated with an improved quality in scar formation.

Animals↗

Laparoscopy and collagen metabolism.

The collagens represent a vital component within the wound healing process and physiological scar formation. Therefore, analysing the influence of new operative procedures on collagen metabolism is of great surgical interest. As the endoscopic technique has, nowadays, become routinely applied for diverse abdominal diseases worldwide, we present a review of literature facing its impact on collagen biology.

Collagen↗

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↗

Validation of IC-VIEW fluorescence videography in a rabbit model of mesenteric ischaemia and reperfusion.

BACKGROUND/AIMS: Mortality in mesenteric ischaemia can be reduced by an optimised extent of resection. Up to now, no technique supplementing a surgeon's experience has achieved clinical acceptance. Besides a qualitative interpretation, the new technique of computer-assisted laser-fluorescence videography affords quantification of staining intensities. The aim of this study was to investigate the scientific value of this technique in mesenteric ischaemia in a rabbit model of controlled mesenteric ischaemia and reperfusion. METHODS: We used an established rabbit model of mesenteric ischaemia (group I, n=6) and reperfusion (group II, n=6). In each animal, three loops (each of 10 cm) of the small intestine were clamped (group I, 40 min; group II, 60 and 20 min reperfusion). For further evaluation, all loops were divided into five segments of 2 x 2 cm (total number of investigated areas, n=180). Measurement of vascular patency was performed by laser-fluorescence videography (pixel intensity per second). As standard, we used radioactive microspheres (impulse per minute per gram). In addition, the extent of ischaemic tissue damage was identified by histological examination. Statistical data were analysed by using regression analysis to define the regression coefficient r. RESULTS/FINDINGS: Laser-fluorescence videography and the microsphere technique demonstrated a close and linear correlation: ischaemic segments, r=0.90+/-0.07; reperfusion segments, r=0.85+/-0.02; overall, r=0.92+/-0.07. There was no reproducible correlation to cellular damage in histology. INTERPRETATION/CONCLUSION: Computer-assisted laser-fluorescence videography is a feasible, reliable, and valid experimental method for the detection of mesenteric blood supply and intestinal microcirculation. Clinical application is conceivable in mesenteric ischaemia and infarction as well as the operative transposition of intestine. As limiting values to identify the irreversible necrosis are not yet defined, further studies have to analyse the clinical impact more precisely.

Animals↗

Incisional intercostal hernia after a nephrectomy.

The aim of the present case report is to present the diagnostic and therapeutic challenge of intercostal incisional hernia. We report on a female patient with leftsided intercostal incisional hernia between the eleventh and twelfth rib due to preceding lumbar incision for tumor nephrectomy. Because of its infrequence, diagnosis was established late although simple clinical examination and ultrasound investigation displayed the hernia. At laparotomy, a 5x5 cm(2) fascial defect with a colonic sliding hernia was found. Hernia repair using permanent mesh reinforcement in the retromuscular position is described. Abdominal incisional hernia in the intercostal region is rare and therefore easily overlooked. As with other incisional hernias, the hernia repair using mesh implantation in the retromuscular region is technically feasible and represents the treatment of choice.

Hernia, Ventral↗

The rare epidemiologic coincidence of diverticular disease and advanced colonic neoplasia.

BACKGROUND AND AIMS: In Western industrialised countries the prevalence of neoplastic colonic lesions and diverticular disease markedly increases with age. In contrast, the coincident occurrence of both diseases seems to fall below their individual epidemiologic estimates. Because directly comparing data are rare, this retrospective study evaluates the coincidence of neoplastic lesions and diverticular disease. PATIENT AND METHODS: A total of 1,838 patients from 1986 to 2000 were admitted to the study. For 1,326 patients-56% male (n=741), 44% female (n=585), mean age 64 (+/-11.83 SD)-with a resection due to colonic cancer, the documented findings of colonoscopy, colonic contrast enema, and/or histopathology were analysed with regard to the prevalence of colonic diverticulosis. In 512 patients--51% male (n=263), 49% female (n=249), mean age 60 (+/-12.59 SD)--with a colonic resection due to diverticulitis, the synchronous or metachronous occurrence of neoplastic colonic lesions was recorded using the database of the Tumour Centre, Aachen. To compare the observed results with published epidemiology, statistical analysis included age-referred binomial tests and an age-stratified analysis (Cochran-Mantel-Haenszel test). Odds ratios (OR) were also calculated. P<0.05 was considered to indicate locally statistical significance. RESULTS: In the cancer group, we found a statistically significant reduced rate of diverticula in nearly all age categories and the age-stratified analyses (corresponding OR 0.30-0.51). Consistently, the diverticulitis group revealed a statistically significant decreased rate of advanced colonic neoplastic lesion in nearly all age categories and all age-stratified analyses (corresponding OR 0.13-0.43). CONCLUSION: Our results indicate that patients with colonic neoplastic lesions or diverticular disease probably form heterogeneous groups. Because current results from molecular biology emphasize the impact of the extracellular matrix on the genesis of diverticulosis and colonic cancer, the observed heterogeneity could be an expression of a distinct composition of the local milieu.

Adult↗

Intraabdominal adhesion formation of polypropylene mesh. Influence of coverage of omentum and polyglactin.

BACKGROUND: Adhesions after intraabdominal surgical procedures are related to high morbidity and mortality. Biomaterials, particularly those made of polypropylene, in the intraabdominal position have to be considered as pathophysiological cofactor in a multifactorial process of adhesion formation. To investigate the adhesive potential induced by the biomaterial, an animal model was performed. In addition, the influence of coverage by omentum or a polyglactin barrier was investigated. METHODS: In, 18 Chinchilla rabbits the biomaterial was placed laparoscopically using the intraperitoneal onlay mesh technique. Using this model, a polypropylene-polyglactin mesh compound (PPMC) was used with three different implantation techniques: group 1, PPMC implantation without coverage (PPMC): group 2, PPMC implantation with additional omentum coverage (PPMC-O): and group 3, PPMC implantation with coverage of an absorbable polyglactin mesh (PPMC-V). The degree of adhesion formation was measured 90 days after implantation by computer-assisted planimetry. Morphometric examination followed the explantation analyzing the amount of foreign body response. RESULTS: We found a significant reduction of adhesion formation for the PPMC and PPMC-O groups compared to the PPMC-V group, in which dense adhesions were found. Morphometric investigations of the perifilamental granulomas of the pure (PPMC) group revealed a typical foreign body reaction with a mild to moderate fibrosis around all mesh fibers. However, tissue specimens of the PPMC-O and PPMC-V groups indicated a similar inflammatory reaction but significantly increased connective tissue formation around the polymer fibers compared to the pure PPMC group. CONCLUSION: The intraabdominal placement of a pure PPMC shows a neoperitonealization and perifilamental collagenous ingrowth with almost no adhesions. Coverage with omentum (PPMC-O) or polyglactin mesh (PPMC-V) resulted in a significant increase in inflammation and perifilamentary connective tissue formation.

Animals↗

[Incisional hernia].

With a long-term incidence of 10-20%, incisional hernias remain one of the most common surgical complications. Beside technical causes, wound-healing problems are increasingly being discussed. Conventional suture repair shows disappointing results and should be used only in selected cases. By the implantation of mesh prostheses, notable improvement could be achieved, with recurrence rates of <10%. Its main principle is retromuscular mesh reinforcement of the entire scar. Particularly in the neighbourhood of osseous structures, only retromuscular placement allows sufficient subduction of the mesh by healthy tissue of at least 5 cm in all directions. Preparation must take into account the special anatomic features of the abdominal wall, especially in the area of the Linea alba and Linea semilunaris.

Abdominal Wall↗

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↗