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Query: UMLS:C0019270 (hernia)
 15,856 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

On 20 rabbits a defect in the abdominal wall was closed by a carbon cloth (SIGRATEX KDS). A tensile force test and a histological examination was performed. Eleven days and 3 months after implantation, 10 animals with an operative-produced abdominal wall hernia and 10 normal animals were controls. A tensile force test on the specimen 3 months after implantation revealed a strength twice as high as on the normal abdominal wall. Eleven days after surgery the strength was equal to the scar tissue of the hernias. Histologically, a connective tissue ingrowth into the implant was observed, which enveloped the single carbon fibers. Collagen fibers in the direction of the carbon filaments were present. Foreign body giant cells were always seen. These results indicate that a carbon cloth seems to be suitable for the repair of abdominal wall hernias.
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PMID:[Closure of abdominal wall defects without tension using a carbon cloth implant (author's transl)]. 644 50

Collagen, as biocompatible and bioactive non-specific polymer, occupies prominent position in the field of tissue engineering. The advanced biomaterials prefer collagen as a matrix for biodegradable implants as are biosynthetic skin substitutes, tendon and ligament substitutes, but also cartilage. Many studies notice the application of chemically modified collagen membranes for hernia and anastomoses reparations, vascular prosthetic materials, or for collagen tubes used in regeneration of peripheral nerves. Besides of defining main problems of tissue engineering, the paper analyses the developmental tendency of these biomaterials in the world, and compares it with the situation in Slovak Republic.
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PMID:[Use of membranes based on collagen as tissue substitutes]. 1064 53

Wound healing encompasses coagulation, inflammation, angiogenesis, fibroplasia, contraction, epithelialisation and remodeling. A granulation tissue is produced following incision of tissue such as skin, abdominal wall or the gastrointestinal tract, and the strength of the wound is determined primarily by the collagen content early in the healing course. Few models are available to study wound healing in man. The percutaneous insertion of expanded poly-tetrafluoroethylene tubes (ePTFE) into the subcutaneous tissue has been an established model for 20 years. The procedure is performed using a local anesthesia. The model has a diameter of 2.5 mm, a length of 5-10 cm and a pore size of 90-120 microns which is substantially more than that of vascular grafts. The polymer accumulates granulation tissue, the architecture of which resembles that of a normal surgical wound. Previous studies on the use of the ePTFE model in wound healing research are summarized in detail. Histological and immunohistochemical analyses of the granulation tissue deposited in the model were undertaken. The content of amino acids following hydrolysis of the granulation tissue was determined applying spectrophotometric or HPLC assays. Collagen amounts accumulated in the model are expressed as hydroxyproline per length of ePTFE or per total protein. Following a study in rats we examined 85 healthy volunteers and 158 surgical patients in the studies. Higher contents of hydroxyproline were found 10 days after implantation as compared to 5 days with considerable inter-person variation. Regarding median values there was a 25% difference between two measurements performed on two distinct ePTFE tubes from the same person, and a 12% difference between values obtained from two different pieces of the same ePTFE. Higher accumulation levels of hydroxyproline did not result in higher variability. Deposition of proline in the model correlated closely to total protein content. The ePTFE and a modified PVA model were compared in surgical patients. No reproducible measurements of hydroxyproline deposition were obtained with the PVA model as opposed to the ePTFE model. It is concluded that the modified PVA model is inadequate for determination of collagen deposition in subcutaneous granulation tissue. We found no correlation between collagen deposition levels obtained with placement of the ePTFE model in the subcutaneous tissue of the arm and in an uncomplicated surgical wound of the groin in the same patient, respectively. Significantly higher collagen deposition levels in the model were found in the surgical wound. Conversely, there was a significant correlation between protein deposition levels obtained at the two sites. Patients undergoing minor surgery (groin hernia repair) did not differ from healthy non-traumatized volunteers as regards deposition of collagen in subcutaneous tissue of the arm, whereas patients subjected to major general surgery demonstrated a significant decline during the postoperative phase compared to a preoperative evaluation. This decline was enhanced in patients who had infectious complications. Non-smoking volunteers were found to specifically accumulate more collagen (median value 82%) than smokers matched for age and gender. Irrespective of the smoking status women accumulated significantly more collagen in the model than men. These findings were re-tested in a prospective series leading to the same conclusion. Matrix metalloproteinases (MMP-2 and MMP-9) were determined in wound fluid obtained from the subcutaneous cavities of herniotomy wounds 24 and 48 h after operation. A significant and inverse correlation was demonstrated between MMP-9 after 24 h and accumulation levels of collagen in the ePTFE tube 10 days after implantation in the wound. Finally, it was demonstrated that local application of granulocyte-macrophage colony-stimulating factor into the ePTFE model during implantation specifically and dose-dependently reduced the number of fibroblasts and deposition of collagen. The doses chosen for the experiments resulted in both a local and a systemic effect. It is concluded that the minimally invasive ePTFE model, despite a certain level of variability, presently provides one of the best possibilities of evaluation of the wound healing potential in both volunteers and patients under various conditions. We found the model convenient for the assessment of both matrix deposition during wound healing and the influence of several factors including demographic characteristics, trauma, tobacco smoking, drugs and tissue degrading components of the wound.
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PMID:Collagen deposition in the subcutaneous tissue during wound healing in humans: a model evaluation. 1462 92

Laparostomy wound management is a difficult problem especially with a stoma and the potential risk of infection. A case describing the use of a permanent porcine dermal collagen implant in the repair of a massive ventral hernia, in a patient with a large post-laparostomy defect and colostomy is outlined. The implant was not rejected, and after 12 months, there was no evidence of residual or recurrent hernia. The search for the ultimate biomaterial for reconstructing abdominal wall defects is ongoing. Collagen based implants appear to have many of the requirements that an ideal material should possess.
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PMID:Anterior abdominal wall reconstruction with a Permacol implant. 1674 4

Collagen types I, II, and III are the most abundant extracellular matrix (ECM) proteins. Collagenase is a member of the matrix metalloproteinase (MMP) family of enzymes, and is the principal enzyme involved with collagen degradation. Cellular-ECM interactions are vitally important to tissue structure and function. In this review, we summarize recent work that highlights the role of collagenase in ECM remodeling and repair, and further report that alterations of collagenase expression, function, and/or regulation are found in many diverse disease states, including aortic aneurysms, tumor invasiveness and their metastases, and hernias. Collagenase is intimately involved in many surgical diseases, and represents a potential target for therapy.
Hernia 2006 Dec
PMID:Collagenase and surgical disease. 1697 44

Hiatus hernia (HH) is a condition characterized by herniation of the intra-abdominal organs into the thorax. Of the several types that have been identified, the most common is type I (sliding) HH. Congenital predisposition and acquired factors, for example trauma and iatrogeny, have been identified as causative factors. There is a strong association between gastroesophageal reflux disease and HH-the prevalence of reflux in HH may reach 94%. Many methods have been used to treat reflux disease and HH, among which are laparoscopic techniques, which gained popularity as a safe method of treatment. Primary crural repair without mesh application was found to have a recurrence rate of up to 42%. This led to the introduction of mesh in HH repair, which was associated with a significant decrease in recurrence rate. Collagen and its relation to hernia have been investigated for several decades. Collagen has mechanical properties sufficient to enable it to support healed scars and other tissues. Nineteen distinct types of collagen have been recognized, the most common of which are types I and III. Type III collagen is the major constituent of early granulation tissue whereas type I predominates as healing proceeds. Collagen fibers are imbedded in extracellular matrix (ECM), which is in continuous process of synthesis and degradation under the action of matrix metalloproteinases. Many authors have studied the role of collagen in ventral hernia and have even defined hernia as a disease of the ECM. The relationship between collagen and HH, and its recurrence, is not fully understood and needs further investigation.
Hernia 2006 Dec
PMID:Collagen metabolism and recurrent hiatal hernia: cause and effect? 1702 73

This work studied the reconstruction of an abdominal wall defect by a human acellular collagen matrix. The abdominal wall defect was cured in 40 rats by implanting (i) polypropylene (Pro), (ii) polyester (Mers) meshes, and (iii) human acellular collagen matrix with two orientations: fibres in parallel (fascia lata longitudinal [FLL]) or perpendicular (fascia lata transversal [FLT]) to native rats' abdominal walls. Hernia recurrence, adhesions, and histology (for inflammation and remodelling) were assessed at 4 and 8 weeks after implantation. Two large abdominal eventrations were cured by a human acellular matrix in human patients. A higher hernia recurrence rate was observed for rats transplanted with FLL than with FLT/Pro/Mers at 4 and 8 weeks after implantation. A lower adhesion rate was achieved for FLL/FLT than for Pro/Mers meshes (p<0.05). A decrease in immunologic cell infiltrations in FLL/FLT was observed between day 30 and day 60 (p<0.05). Collagen, elastin, and muscular tissues were found only in FLL/FLT matrix; a weaker muscular cell infiltration for FLL occurred at 8 weeks. Human abdominal eventrations were totally cured by using FLT as confirmed by computed tomography scanning at 12 and 16 months after implantation. In conclusion, human acellular collagen matrix, placed in an FLT position, can induce an abdominal wall reconstitution without adhesions and hernia recurrence.
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PMID:Regeneration of abdominal wall musculofascial defects by a human acellular collagen matrix. 1828 Oct 88

Fetal tracheal occlusion (TO) is currently used to treat severe cases of congenital diaphragmatic hernia (DH). Clinical and experimental studies suggest an improved postnatal outcome, but lung tissue mechanics after TO have not been studied. We determined the effect of TO on mechanical impedance and lung tissue components in a rabbit model for DH. At 23 days of gestation (term = 31 days) either a sham thoracotomy or a diaphragmatic defect was induced. DH fetuses were randomly assigned to undergo 5 days later TO. Fetuses were delivered by term cesarean section to determine lung to body weight ratio (LBWR), dynamic lung mechanics and lung impedance. Airway resistance (R(aw)), elastance (H(L)), tissue damping (G(L)) and hysteresivity (G(L)/H(L)) were calculated from impedance data. Collagen I and III and elastin were quantified histologically. LBWR was significantly increased by TO compared to DH (P < 0.001) and resistance and compliance of the respiratory system (R(rs), C(rs)) were improved as well. TO resulted in a significant decrease of R(aw) comparable to observations in sham-fetuses, without effect on lung tissue mechanics H(L), G(L) and hysteresivity. This coincides with a significant decrease of collagen I, III and elastin in comparison to DH fetuses. In this first report on lung tissue mechanics in a rabbit model of DH, TO had a substantial effect on tissue morphology yet this was not mirrored in lung mechanics. We conclude that the effect of TO on lung mechanics without in utero reversal of occlusion, is dominated by airway remodeling.
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PMID:The effect of fetal tracheal occlusion on lung tissue mechanics and tissue composition. 1913 93

Abdominal hernia repair is one of the most common surgical procedures. Current data indicate that the best treatment results are achieved with use of synthetic material to reinforce weakened abdominal wall. Prosthetic materials utilized for hernia repair induce adhesions with underlying viscera. They should be therefore separated from them by a layer of peritoneum otherwise adhesions may cause to serious complications such as bowel-skin fistulas. The aim of our work was to determine if implantation of our collagen membrane into abdominal wall defect induce adhesions in rat model of ventral hernia. The collagen film was obtained by acetic acid extraction of rat tail tendons and than casting the soluble fraction onto polyethylene shits. Abdominal wall defect was created in 10 Wistar male rats. Collagen membranes were implanted into the defect using interrupted polypropylene stitches. After 3 months of observation all animals were sacrificed. No adhesions between path structure and bowel developed. In one often rats (10%) adhesion between fixating stitch and omentum was observed. Complete mesothelium lining and vascular ingrowth were microscopically observed within implanted structure. Promising result requires further confirmation in a larger series of animals.
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PMID:[Abdominal wall reconstruction with collagen membrane in an animal model of abdominal hernia. A preliminary report]. 1913 74

Limitations of synthetic biomaterials for abdominal wall repair have led investigators to seek naturally derived matrices, such as human acellular dermis, because of their excellent biocompatibility and their ability to naturally interface with host tissues with minimal tissue response. In this study, we investigated two different biomaterials derived from human dermis (FlexHD acellular dermis and FlexHD acellular dermis-thick) in a rabbit abdominal hernia repair model. One quarter of the abdominal wall was replaced with each biomaterial, and the animals were followed for up to 24 weeks. Rabbit hernias repaired with AlloDerm, a commercially available acellular dermal matrix, and sham operated animals served as controls. Retrieved samples of these implants were assessed grossly and histologically. Collagen production measurements and tension studies were performed. FlexHD acellular dermis, FlexHD acellular dermis-thick, and AlloDerm maintained their strength in the rabbit hernia repair model with no incidence of hernia formation or bowel adhesion. The exact size measurements at 24 weeks were 217.0 +/- 20.9% for FlexHD acellular dermis, 200.8 +/- 23.5% for FlexHD acellular dermis-thick, and 209.7 +/- 32.9% for AlloDerm. Macroscopic and microscopic evaluation showed excellent integration and tissue formation. All biomaterials studied harbored cells that produced new collagen fibers, and a six-fold increase in these fibers was observed at 24 weeks. This study shows that acellular biomaterials derived from human dermis are suitable for abdominal hernia repair.
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PMID:In vivo evaluation of acellular human dermis for abdominal wall repair. 2001 94


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