Peritoneal repair and post-surgical adhesion formation.
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It was shown in 1919 that peritoneal healing differs from that of skin. When a defect is made in the parietal peritoneum the entire surface becomes epithelialized simultaneously and not gradually from the borders as in epidermalization of skin wounds. While multiplication and migration of mesothelial cells from the margin of the wound may play a small part in the regenerative process, it cannot play a major role, since new mesothelium develops in the centre of a large wound at the same time as it develops in the centre of a smaller one. Development of intraperitoneal adhesions is a dynamic process whereby surgically traumatized tissues in apposition bind through fibrin bridges which become organized by wound repair cells, often supporting a rich vascular supply as well as neuronal elements. (+info)
Peritoneal healing and adhesion formation/reformation.
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Intra-abdominal adhesion formation and reformation after surgery is a cause of significant morbidity, resulting in infertility and pain. The understanding of the pathogenesis of adhesion formation and reformation especially at the cellular and molecular level can help to further develop more effective treatments for the prevention of adhesion formation and reformation. Following an injury to the peritoneum, fibrinolytic activity over the peritoneal surface decreases, leading to changes in the expression and synthesis of various cellular mediators and in the remodelling of the connective tissue. The cellular response to peritoneal injury and adhesion formation and reformation are reviewed. Analysis of the available literature data on the cellular mediators in the peritoneal fluid showed variation in results from different investigators. The potential sources of variability and error are examined. It is still unclear if there is significant individual variation in the peritoneal response to injury. (+info)
Clinical implications of postsurgical adhesions.
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Adhesion development can have a major impact on a patient's subsequent health. Adhesions are a significant source of impaired organ functioning, decreased fertility, bowel obstruction, difficult re-operation, and possibly pain. Consequently, their financial sequelae are also extraordinary, with more than one billion dollars spent in the USA in 1994 on the bowel obstruction component alone. Performing adhesiolysis for pain relief appears efficacious in certain subsets of women. Unfortunately even when lysed, adhesions have a great propensity to reform. Adhesions are prevalent in all surgical fields, and nearly any compartment of the body. For treatment of infertility and recurrent pregnancy loss, lysis of intrauterine adhesions results in improved fecundability and decreased pregnancy loss. (+info)
Evidence-based prevention of post-operative adhesions.
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Despite decades of research, numerous new product ideas and 'carefully considered opinions' of recognized experts, very few products for the prevention of post-operative adhesions have met the requirements for Level 1 evidence of safety and efficacy. Those that have are useable only at laparotomy. Several new liquid products intended for use at laparoscopy are in various stages of development and clinical investigation. Hopefully, some will prove to be both simple to use and efficacious. Even if this occurs, it must be remembered that a reduction in post-operative adhesions does not necessarily produce a better clinical outcome. Our common sense suggests that fewer adhesions should logically result in less pain, more pregnancies, fewer bowel obstructions and less long-term morbidity. We believe that 'fewer adhesions' is a good thing, but we have no controlled human trials to prove this. How much of a reduction in post-operative adhesions is necessary before it is clinically relevant? A single adhesion in the wrong anatomic location may be catastrophic. How do we measure this? Until these and other questions have been answered (if ever), we have nothing more than educated guesses that all these efforts are warranted. (+info)
Evaluation of polyoxyethylene homopolymers for buccal bioadhesive drug delivery device formulations.
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Our objective was to evaluate the application of polyoxyethylene homopolymers in buccal bioadhesive drug (BBD) delivery device formulations. The bioadhesive strength of four different molecular weight (MW) polyoxyethylene polymers was measured by Instron tensile tester using glass plate and bovine sublingual tissue as substrate surfaces. Several BBD device formulations containing polyoxyethylene polymer (MW 7,000,000) were prepared by direct compression and compression molding processes. The prepared BBD devices were evaluated for their elasticity, in vitro adhesion and drug release characteristics. The in vivo bioadhesion characteristics of a placebo compression molded device were examined in 3 adult healthy male beagle dogs. The bioadhesive strength of polyoxyethylene polymers appeared to be directly related to their molecular weights. When bovine sublingual mucosa or a glass plate was used as model mucosal substrate surface, the rank order of bioadhesive strength of different molecular weight polyoxyethylene polymers was similar. The bioadhesive strength of devices prepared by the compression molding process was greater than those prepared by direct compression, but the kinetics of drug release were independent of the process used for the preparation of the devices. The drug release and the bioadhesive strength of the similarly prepared device formulations appeared to be dependent on the drug:polymer ratios. The elasticity of the BBD devices prepared by compression molding was improved by the inclusion of polyisobutylene polymer in the formulations. When adhered to the oral cavity of the dogs, the compression molded placebo BBD device exhibited adhesion for at least 4 hours and appeared to show no signs of local irritation. In conclusion, BBD devices containing polyoxyethylene polymer (MW 7,000,000) can be prepared by direct compression or compression molding process in order to provide controlled drug release to the oral cavity while maintaining appropriate bioadhesive characteristics. (+info)
Magnetic resonance imaging of the peritoneal cavity among peritoneal dialysis patients, using the dialysate as "contrast medium".
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The objectives of this study were to evaluate whether adequate observation of abdominal pathologic features related to peritoneal dialysis (PD) was possible with magnetic resonance imaging (MRI) under routine conditions, i.e., against the background of the dialysate and without contrast medium. For 16 male and seven female patients (mean age, 51.8 +/- 15.0 yr; mean duration of PD, 324 +/- 542 d), 25 peritoneal MRI studies were performed with the intraperitoneal dialysate as usual. Indications were symptoms or combinations of symptoms, such as leakage or abdominal wall edema (n = 3), bloody dialysate (n = 4), suspected herniation (n = 1), suspected ultrafiltration failure (n = 2), and abdominal pain (n = 5), or routine assessment after initiation of PD (n = 12). The MRI protocol, which was performed with a 1.0-T scanner, consisted of breath-hold, coronal and transverse, T2-weighted, half-Fourier single-shot turbo spin-echo sequences, using a standard body-array coil. MRI studies were well tolerated and successfully completed for all except two patients. Results indicated a leak along the catheter (n = 1), a leak in an umbilical hernia (n = 1), suspected leakage (n = 1), hernias (n = 5, in three patients), intraperitoneal adhesions (n = 5, in four patients), a ruptured ovarian cyst (n = 1), and pleural effusions (n = 4). Pathologic findings unrelated to PD or located extra-abdominally were observed in 19 of the 25 studies. The catheter tip position was easily identified for all patients. In conclusion, this first report on peritoneal MRI using only dialysate as the "contrast medium" indicates that MRI permits detailed observation of all relevant, PD-related, abdominal pathologic features against the dialysate background, thus avoiding system contamination (and thus the risk of peritonitis). (+info)
IL-1, IL-6 and TNF-alpha concentrations in the peritoneal fluid of women with pelvic adhesions.
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BACKGROUND: Pelvic adhesions are a significant cause of morbidity and are associated with infertility and pain. The three pro-inflammatory cytokines interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-alpha are involved in adhesion formation/reformation. METHODS: The concentration of these three cytokines was examined in the peritoneal fluid of women undergoing laparoscopy, in order to examine the factors affecting their concentrations, with specific reference to the presence or absence of adhesions. RESULTS: We found that the concentration of TNF-alpha in the peritoneal fluid was significantly correlated to the menstrual cycle day (P < 0.01), with increasing concentration as the menstrual cycle progressed from the follicular to the luteal phase. In contrast, IL-1 and IL-6 levels did not show any variation throughout the menstrual cycle. Increased TNF-alpha was found in patients with pelvic adhesions compared with those with normal pelvis; the concentration of TNF-alpha was highest in mild compared with severe adhesions. In contrast, IL-1 concentration was higher in the presence of severe adhesions. IL-6 levels were significantly correlated with the grade of endometriosis (P < 0.05), but there were no significant correlations of either TNF-alpha or IL-1 concentrations with the various grades of endometriosis. CONCLUSION: The exact role of TNF-alpha and IL-1 in adhesion formation is still unknown, but the results from this study suggest that their concentration in the peritoneal fluid is associated with the degree of adhesions present. (+info)
An evaluation of baseline risk factors predicting severity in juvenile idiopathic arthritis associated uveitis and other chronic anterior uveitis in early childhood.
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BACKGROUND/AIMS: The clinical course for childhood chronic anterior uveitis can vary from mild, self limiting disease to bilateral blindness. The purpose of this study was to identify those risk factors at onset that predict disease severity. METHODS: A retrospective case note review of all patients with painless anterior uveitis diagnosed from 1982 to 1998. Patients were divided into two cohorts based on route of referral, diagnosis, and compliance with treatment. The standard cohort consisted of only those diagnosed from routine screening of juvenile idiopathic arthritis. RESULTS: Complications-cataract surgery, ocular hypertension treatment, and visual acuity <6/24. Remission: inactive uveitis on no topical treatment for >6 months. Results-163 patients were included. 34 patients (21%) developed at least one complication. The most significant predictor of complications was severe disease at onset (p = 0.001). Other factors included uveitis at the first examination (p = 0.034), membership of the non-standard cohort (p = 0.0001), non-oligoarticular disease (p = 0.02), and late onset arthritis (p = 0.024). Male sex was associated with increased complications in the standard cohort (p = 0.001). Factors predisposing to remission included membership of the standard cohort (p = 0.003), onset after 1990 (p = 0.016), white race (p = 0.015), mild disease onset (p = 0.003), and a long gap between arthritis and uveitis onset (p = 0.015). CONCLUSIONS: It is possible to characterise the severity of those with childhood chronic anterior uveitis at the onset of disease. The majority of patients remit without visually disabling complications. It may be possible to reduce the complication rate by targeting aggressive immunosuppression on high risk patients before complications develop. (+info)