AIM: Despite the substantial progress that has been achieved in interventional cardiology and cardiac electrophysiology, endovascular intervention for the diagnosis and treatment of central nervous system (CNS) disorders such as stroke, epilepsy and CNS malignancy is still limited, particularly due to highly tortuous nature of the cerebral arterial and venous system. Existing interventional devices and techniques enable only limited and complicated access especially into intra-cerebral vessels. The aim of this study was to develop a micro-catheter magnetically-guided technology specifically designed for endovascular intervention and mapping in deep CNS vascular structures. METHODS: Mapping of electrical brain activity was performed via the venous system on an animal dog model with the support of the NIOBE II system. RESULTS: A novel micro-catheter specially designed for endovascular interventions in the CNS, with the support of the NIOBE II technology, was able to reach safely deep intra-cerebral venous structures and map the electrical activity there. Such structures are not currently accessible using standard catheters. CONCLUSION: This is the first study demonstrating successful use of a new micro-catheter in combination with NIOBE II technology for endovascular intervention in the brain.
- MeSH
- elektroencefalografie MeSH
- endovaskulární výkony přístrojové vybavení metody MeSH
- katétry MeSH
- magnety MeSH
- mapování mozku přístrojové vybavení metody MeSH
- mozková angiografie MeSH
- počítačové zpracování obrazu MeSH
- psi MeSH
- velký mozek krevní zásobení fyziologie radiografie MeSH
- zvířata MeSH
- Check Tag
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVE: Abnormal haemodynamics is commonly agreed to be a major contributor to the development of distal anastomotic intimal hyperplasia. A new vascular graft design proposed by computational studies was used to demonstrate its surgical feasibility and to compare it with the conventional graft in a porcine model. METHOD: The device was used in 12 eight-month-old pigs, six received the new graft and six had a conventional graft. The proximal graft end was implanted into the aorta, the distal graft end was implanted into the iliac artery. The host artery was ligated in order to simulate occlusion. At 20 weeks after surgery the pigs were killed and the device was excised for histological and morphometric analysis. RESULTS: In five experimental grafts the reconstruction was occluded due to thrombosis; only one prosthesis was patent showing a minimum of neointimal hyperplasia. In the control group too only three of the six grafts were patent. A histological analysis revealed, as the cause of occlusion, fibrous tissue overgrowth corresponding in structure to neointimal hyperplasia. Differences in the number of obliterations and in occlusion rates between the profiles of the two groups were evaluated using the median test (P<0.05). The results were not statistically significant. CONCLUSION: Although mathematical modelling had shown significant haemodynamic benefits of a naturally bifurcated graft, our study did not confirm its superiority over conventionally used prostheses.
- MeSH
- aorta patologie chirurgie MeSH
- cévní endotel patologie MeSH
- cévní protézy škodlivé účinky MeSH
- hyperplazie MeSH
- prasata MeSH
- protézy - design MeSH
- studie proveditelnosti MeSH
- tunica intima patologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
Specific contrast ultrasound is widely applied in diagnostic procedures on humans but remains underused in veterinary medicine. The objective of this study was to evaluate the use of microbubble-based contrast for rapid ultrasonographic diagnosis of thrombosis in small animals, using male New Zealand white rabbits (average weight about 3.5 kg) as a model. It was hypothesized that the use of microbubble-based contrast agents will result in a faster and more precise diagnosis in our model of thrombosis. A pro-coagulant environment had been previously established by combining endothelial denudation and external vessel wall damage. Visualization of thrombi was achieved by application of contrast microbubbles [sterically stabilized, phospholipid-based microbubbles filled with sulfur hexafluoride (SF6) gas] and ultrasonography. As a result, rapid and clear diagnosis of thrombi in aorta abdominalis was achieved within 10 to 30 s (mean: 17.3 s) by applying microbubbles as an ultrasound contrast medium. In the control group, diagnosis was not possible or took 90 to 180 s. Therefore, sterically stabilized microbubbles were found to be a suitable contrast agent for the rapid diagnosis of thrombi in an experimental model in rabbits. This contrast agent could be of practical importance in small animal practice for rapid diagnosis of thrombosis.
- MeSH
- aorta abdominalis patologie ultrasonografie MeSH
- fluorid sírový diagnostické užití MeSH
- kočky MeSH
- kontrastní látky diagnostické užití MeSH
- králíci MeSH
- mikrobubliny diagnostické užití veterinární MeSH
- modely nemocí na zvířatech MeSH
- nemoci koček patologie ultrasonografie MeSH
- neparametrická statistika MeSH
- tromboembolie patologie ultrasonografie veterinární MeSH
- ultrasonografie dopplerovská metody veterinární MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A device for continuous infusion of microbubbles (MBs) 'Infucon' has been designed, constructed and tested on rabbits. The device prevents MBs from flotation and accumulation in the layer directly below the surface in the syringe injection during i.v. application. Homogenous i.v. application of MBs was tested on 16 male New Zealand White rabbits (average weight about 3.5 kg). Two sorts of MBs were used - a set of commercial SonoVue diagnostic microbubbles (Bracco) and pegylated DPPC microbubbles (PegMBs), which had been prepared in our laboratory. Sulphur hexafluoride was used as a filling gas. The application of MBs by continuous infusion via Infucon prolonged the ultrasound signal period in the heart of the rabbit to 12 min in comparison to about 1 min observed in bolus application. No adverse effects were observed on the tested rabbits after the MB application via Infucon. The principle employed in the prototype device Infucon could be used for development of the device intended for clinical applications.
- MeSH
- 1,2-dipalmitoylfosfatidylcholin chemie MeSH
- časové faktory MeSH
- fluorid sírový diagnostické užití MeSH
- fosfolipidy diagnostické užití MeSH
- intravenózní infuze MeSH
- králíci MeSH
- mikrobubliny diagnostické užití MeSH
- polyethylenglykoly chemie MeSH
- ultrasonografie metody MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
The goal of this pilot study was to create an experimental model of myocardial infarction (for subsequent evaluation of the effectiveness of an alternative way of stem cell application - intracoronary cell infusion in the management of acute myocardial infarction). Four experimental animals, female pigs weighing between 30 and 40 kg, were used in the initial phase of this study to create an experimental model of acute myocardial infarction. An experimental myocardial infarction was performed via occlusion of the interventricular arm of the left coronary artery for 90 min. The hearts were examined 1 h, 3 days, 5 days, and 7 days after the procedure. Macroscopically, red infarction characteristic of reperfusion was found. Microscopically, the healing process with granulation tissue production/collagen deposition was remarkably accelerated compared to literature data. Repair processes in reperfused experimental myocardial infarction and/or reperfused autopsy specimens should not be evaluated on the basis of literature data only. Large collections of extracellular calcium were present. This phenomenon is not well described in the literature and probably has the potential for significantly interfering with the repair process. The histopathology of reperfused acute myoardial infarction deserves to be studied in further investigations.
- MeSH
- buněčná inkluze metabolismus MeSH
- granulační tkáň patologie MeSH
- infarkt myokardu metabolismus patologie chirurgie MeSH
- modely nemocí na zvířatech MeSH
- pilotní projekty MeSH
- prasata MeSH
- reperfuzní poškození myokardu metabolismus patologie chirurgie MeSH
- transplantace kmenových buněk MeSH
- vápník metabolismus MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
INTRODUCTION: The aim of the study was to evaluate and compare the efficacy of standard unfractionated heparin (UFH) and low-molecular weight heparins (LMWH's). MATERIALS AND METHODS: We modified a previously published rabbit model of arterial thrombosis prevention [1,2] to compare unfractionated heparin and two different doses of two low-molecular weight heparin fragments--nadroparin and enoxaparin. Thrombosis in the distal aorta was triggered by vessel wall injury and critical stenosis. Blood flow in the damaged arterial segment was monitored by a flow probe placed distal to the constrictor. The primary endpoints of the study were: (1) cumulative flow, (2) time to occlusion and (3) residual clot weight. Thirty six animals were split into 6 groups with six animals in each group. Control groups were given saline or heparin and four more groups were used to compare LMWH's at 2 different doses. RESULTS: In our study, all treatments were superior to the saline control group (alpha
- MeSH
- arterie MeSH
- enoxaparin terapeutické užití MeSH
- heparin nízkomolekulární terapeutické užití MeSH
- heparin terapeutické užití MeSH
- klinické zkoušky jako téma MeSH
- králíci MeSH
- nadroparin terapeutické užití MeSH
- trombóza farmakoterapie prevence a kontrola MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
OBJECTIVES: Intracoronary cell transplantation during catheter balloon inflations may be associated with adverse events. We studied the effectiveness of an alternative transplantation technique--intracoronary cell infusion. METHODS: Fourteen pigs, which had survived acute myocardial infarction, were randomized into 2 treatment groups and 2 controls. Three days after infarction, 12 pigs underwent allogeneic intracoronary mononuclear bone marrow cell transplantation using either the standard technique (short-term cell injections during repeat balloon inflations, technique A, n = 6) or continuous intracoronary cell infusion without balloon inflations (technique B, n = 6). Implanted cells were stained with fluorescent dye. After transplantation, the pigs were euthanized and myocardial samples were analyzed by fluorescent microscopy. RESULTS: The mean numbers of fluorescently labeled bone marrow cells in the infarction border zone, in the infarction mid-area and in the center of myocardial infarction were 84, 72 and 55 using technique A, and 29, 57 and 46 using technique B, respectively. The mean cell retention in the infarction border zone of 84 cells for technique A and 29 cells for technique B differed significantly (p = 0.034, two-tailed t test). CONCLUSION: The continuous intracoronary cell infusion technique is a less efficient cell delivery technique as compared with the standard technique using repeat intracoronary balloon inflations.
- MeSH
- financování organizované MeSH
- fluoresceiny MeSH
- fluorescenční barviva MeSH
- fluorescenční mikroskopie MeSH
- infarkt myokardu terapie MeSH
- katetrizace MeSH
- modely nemocí na zvířatech MeSH
- prasata MeSH
- srdeční katetrizace MeSH
- transplantace kostní dřeně metody MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
