BACKGROUND: Understanding the risk factors leading to intracranial aneurysm (IA) rupture have still not been fully clarified. They are vital for proper medical guidance of patients harboring unruptured IAs. Clarifying the hemodynamics associated with the point of rupture could help could provide useful information about some of the risk factors. Thus far, few studies have studied this issue with often diverging conclusions. METHODS: We identified a point of rupture in patients operated for an IAs during surgery, using a combination of preoperative computed tomography (CT) and computed tomography angiography (CTA). Hemodynamic parameters were calculated both for the aneurysm sac as a whole and the point of rupture. In two cases, the results of CFD were compared with those of the experiment using particle image velocimetry (PIV). RESULTS: We were able to identify 6 aneurysms with a well-demarcated point of rupture. In four aneurysms, the rupture point was near the vortex with low wall shear stress (WSS) and high oscillatory shear index (OSI). In one case, the rupture point was in the flow jet with high WSS. In the last case, the rupture point was in the significant bleb and no specific hemodynamic parameters were found. The CFD results were verified in the PIV part of the study. CONCLUSION: Our study shows that different hemodynamic scenarios are associated with the site of IA rupture. The numerical simulations were confirmed by laboratory models. This study further supports the hypothesis that various pathological pathways may lead to aneurysm wall damage resulting in its rupture.
- Publikační typ
- časopisecké články MeSH
Recidiva intrakraniálního aneuryzmatu (IA) po chirurgickém ošetření (klip aneuryzmatu) je v klinické praxi relativně raritní. Pro řešení takové recidivy je nutné individuální rozhodnutí na základě precizní radiodiagnostiky a zkušeností daného týmu. Chirurgická léčba recidiv aneuryzmat je technicky náročnější v porovnání s primární operací vzhledem k postoperačním změnám. Cílem naší práce je shrnout současné znalosti o problematice a managementu recidiv IA po klipu a prezentovat naše zkušenosti s jejich chirurgickou léčbou.
Recurrence of intracranial aneurysms (IA) after surgical treatment (aneurysm clipping) is relatively rare in clinical practice. The treatment of such an aneurysm requires an individualized approach based on precise medical imaging and experience of the team. Surgical treatment of recurrent aneurysms is technically more demanding compared to primary surgery especially due to postoperative changes. The goal of this study is to review current knowledge and management of recurrent IA after clipping and present our experience with such cases.
- Klíčová slova
- klip,
- MeSH
- intrakraniální aneurysma * chirurgie dějiny diagnostické zobrazování klasifikace MeSH
- lidé MeSH
- počítačová rentgenová tomografie MeSH
- recidiva MeSH
- sekundární prevence MeSH
- terciární prevence MeSH
- zobrazování trojrozměrné MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
Nestr.
Roste počet jedinců s náhodně diagnostikovanou mozkovou výdutí, jejíž prasknutí vede k nejtěžší formě cévní mozkové příhody. Metoda počítačového modelování hemodynamiky se snaží popsat patofyziologii a riziko ruptury mozkové výdutě. V našem projektu chceme využít modely hemodynamiky kalkulované na základě neinvazivních radiodiagnostických metod a pomocí vlastního algoritmu vyvinutého v Matematickém ústavu Univerzity Karlovy. Hlavním cílem projektu je u pacientů operovaných pro mozkovou výduť, prasklou i neprasklou, popsat parametry hemodynamiky a tyto korelovat s histologickými změnami cévní stěny vaku aneuryzmatu. Dalším cílem je u skupiny sledovaných neprasklých aneuryzmat, která jsou vedena v multicentrické databázi sdílené několika neurochirurgickými pracovišti v ČR, popsat vývoj hemodynamických parametrů v čase a porovnat s výsledky hemodynamiky prasklých aneuryzmat. Projekt pomáhá vytvářet multioborovou platformu s mezinárodní spoluprácí pro výzkum hemodynamiky mozkových aneuryzmat.; The number of patients incidentally diagnosed for a brain aneurysm, the rupture of which may lead to the most severe type of stroke, is increasing. Modelling hemodynamics in brain aneurysms tries to describe pathophysiology and the risk of rupture of intracranial aneurysms. In our project we will assess models of hemodynamics based non-invasive radiodiagnostic methods and an in-house mathematical algorithm developed at the Mathematical Institute of the Charles University. The main goal of the project is to correlate parameters of hemodynamics with histological changes of the blood vessels wall of the aneurysm sac in patients operated for ruptured as well as unruptured intracranial aneurysms. Another goal of the project is to evaluate hemodynamics in followed unruptured aneurysms from our multicenter database shared among several neurosurgical centers in the Czech Republic and compare with hemodynamic parameters in ruptured aneurysms. The project will help building a multi-modal platform for studying CFD in brain aneurysms with international cooperation.
- MeSH
- cévy patologie MeSH
- hemodynamika MeSH
- intrakraniální aneurysma komplikace patofyziologie MeSH
- lidé MeSH
- počítačová simulace MeSH
- prasklé aneurysma etiologie patofyziologie patologie MeSH
- rizikové faktory kardiovaskulárních chorob MeSH
- Check Tag
- lidé MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- neurologie
- angiologie
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
V posledních letech se rozvinula metodika počítačového modelování toku tekutin v cerebrovaskulární problematice, především pak v oblasti intrakraniálních aneuryzmat. Cílem většiny studií je pochopit patofyziologii vzniku, růstu a ruptury mozkových výdutí a určit ty rizikové hemodynamické parametry, které k těmto procesům vedou. V naší práci shrnujeme současný stav počítačového modelování toku tekutin především z pohledu chirurgie mozkových aneuryzmat a zaměřujeme se na možný přínos pro klinickou praxi.
Computational fluid dynamics have developed in the area of cerebrovascular diseases in recent years, especially in the research of intracranial aneurysms. The goal of most studies is to understand the pathophysiology of the initiation, growth and rupture of brain aneurysms and determine those risk hemodynamic parameters that lead to such processes. In our paper, we summarize the current state of art computational fluid dynamics especially from a surgical point of view of intracranial aneurysms and we focus on its possible contribution in clinical practice.
Methacrylate hydrogels have been extensively used as bridging scaffolds in experimental spinal cord injury (SCI) research. As synthetic materials, they can be modified, which leads to improved bridging of the lesion. Fibronectin, a glycoprotein of the extracellular matrix produced by reactive astrocytes after SCI, is known to promote cell adhesion. We implanted 3 methacrylate hydrogels: a scaffold based on hydroxypropylmethacrylamid (HPMA), 2-hydroxyethylmethacrylate (HEMA) and a HEMA hydrogel with an attached fibronectin (HEMA-Fn) in an experimental model of acute SCI in rats. The animals underwent functional evaluation once a week and the spinal cords were histologically assessed 3 months after hydrogel implantation. We found that both the HPMA and the HEMA-Fn hydrogel scaffolds lead to partial sensory improvement compared to control animals and animals treated with plain HEMA scaffold. The HPMA scaffold showed an increased connective tissue infiltration compared to plain HEMA hydrogels. There was a tendency towards connective tissue infiltration and higher blood vessel ingrowth in the HEMA-Fn scaffold. HPMA hydrogels showed a significantly increased axonal ingrowth compared to HEMA-Fn and plain HEMA; while there were some neurofilaments in the peripheral as well as the central region of the HEMA-Fn scaffold, no neurofilaments were found in plain HEMA hydrogels. In conclusion, HPMA hydrogel as well as the HEMA-Fn scaffold showed better bridging qualities compared to the plain HEMA hydrogel, which resulted in very limited partial sensory improvement.
- MeSH
- axony fyziologie MeSH
- biokompatibilní materiály MeSH
- biologické markery MeSH
- exprese genu MeSH
- extracelulární matrix metabolismus MeSH
- fyziologická neovaskularizace MeSH
- hematoencefalická bariéra metabolismus MeSH
- hojení ran MeSH
- hydrogely * MeSH
- krysa rodu rattus MeSH
- methakryláty * chemie MeSH
- modely nemocí na zvířatech MeSH
- pojivová tkáň MeSH
- poranění míchy etiologie metabolismus patologie terapie MeSH
- regenerace nervu * MeSH
- tkáňové podpůrné struktury MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
While many types of biomaterials have been evaluated in experimental spinal cord injury (SCI) research, little is known about the time-related dynamics of the tissue infiltration of these scaffolds. We analyzed the ingrowth of connective tissue, axons and blood vessels inside the superporous poly (2-hydroxyethyl methacrylate) hydrogel with oriented pores. The hydrogels, either plain or seeded with mesenchymal stem cells (MSCs), were implanted in spinal cord transection at the level of Th8. The animals were sacrificed at days 2, 7, 14, 28, 49 and 6 months after SCI and histologically evaluated. We found that within the first week, the hydrogels were already infiltrated with connective tissue and blood vessels, which remained stable for the next 6 weeks. Axons slowly and gradually infiltrated the hydrogel within the first month, after which the numbers became stable. Six months after SCI we observed rare axons crossing the hydrogel bridge and infiltrating the caudal stump. There was no difference in the tissue infiltration between the plain hydrogels and those seeded with MSCs. We conclude that while connective tissue and blood vessels quickly infiltrate the scaffold within the first week, axons show a rather gradual infiltration over the first month, and this is not facilitated by the presence of MSCs inside the hydrogel pores. Further research which is focused on the permissive micro-environment of the hydrogel scaffold is needed, to promote continuous and long-lasting tissue regeneration across the spinal cord lesion.
- MeSH
- axony patologie MeSH
- biokompatibilní materiály chemie MeSH
- časové faktory MeSH
- fyziologická neovaskularizace MeSH
- hydrogely MeSH
- krysa rodu rattus MeSH
- oligopeptidy chemie MeSH
- polyhydroxyethylmethakrylát chemie MeSH
- poranění míchy patologie patofyziologie terapie MeSH
- poréznost MeSH
- potkani Wistar MeSH
- regenerace míchy fyziologie MeSH
- testování materiálů MeSH
- tkáňové podpůrné struktury chemie MeSH
- transplantace mezenchymálních kmenových buněk * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
