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
Reflecting the first wave COVID-19 pandemic in Central Europe (i.e. March 16th-April 15th, 2020) the neurosurgical community witnessed a general diminution in the incidence of emergency neurosurgical cases, which was impelled by a reduced number of traumatic brain injuries (TBI), spine conditions, and chronic subdural hematomas (CSDH). This appeared to be associated with restrictions imposed on mobility within countries but also to possible delayed patient introduction and interdisciplinary medical counseling. In response to one year of COVID-19 experience, also mapping the third wave of COVID-19 in 2021 (i.e. March 16 to April 15, 2021), we aimed to reevaluate the current prevalence and outcomes for emergency non-elective neurosurgical cases in COVID-19-negative patients across Austria and the Czech Republic. The primary analysis was focused on incidence and 30-day mortality in emergency neurosurgical cases compared to four preceding years (2017-2020). A total of 5077 neurosurgical emergency cases were reviewed. The year 2021 compared to the years 2017-2019 was not significantly related to any increased odds of 30 day mortality in Austria or in the Czech Republic. Recently, there was a significant propensity toward increased incidence rates of emergency non-elective neurosurgical cases during the third COVID-19 pandemic wave in Austria, driven by their lower incidence during the first COVID-19 wave in 2020. Selected neurosurgical conditions commonly associated with traumatic etiologies including TBI, and CSDH roughly reverted to similar incidence rates from the previous non-COVID-19 years. Further resisting the major deleterious effects of the continuing COVID-19 pandemic, it is edifying to notice that the neurosurgical community ́s demeanor to the recent third pandemic culmination keeps the very high standards of non-elective neurosurgical care alongside with low periprocedural morbidity. This also reflects the current state of health care quality in the Czech Republic and Austria.
- MeSH
- chronický subdurální hematom * MeSH
- COVID-19 * MeSH
- lidé MeSH
- neurochirurgické výkony MeSH
- pandemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
Spontánní intrakraniální hypotenze (SIH) je onemocnění, jehož hlavním příznakem je bolest hlavy. V posledních letech zaujala důležité místo v široké diferenciální diagnostice příčin tohoto symptomu. Přispívají k tomu také pokroky, kterých bylo dosaženo při pochopení patofyziologie, zpřesnění diagnostiky a rozšíření terapeutických možností tohoto onemocnění. SIH často postihuje mladé pacienty v produktivním věku a může vést k významnému narušení jejich sociálního i pracovního života. Její rozpoznání a správná léčba tak mají jistě velký význam. V tomto referátu přehledně shrnujeme pohled na patogenezi SIH, současné postupy a doporučení v diagnostice a terapii této nemoci, podpořené typickou kazuistikou, jejíž popis je dostupný v online verzi tohoto referátu..
Spontaneous intracranial hypotension (SIH) is a disease in which headache is the main symptom. Recently, it has become an important part of the broad differential diagnosis of causes of headache. Advances in understanding of pathophysiology, indication of proper imaging modalities, and expansion of microsurgical techniques contributed to increased recognition of the disease. Young patients in productive age commonly suffer from SIH, and it might negatively influence both their social and professional life. Therefore, it is of great importance to recognize the symptoms of the disease and treat it properly. The aim of our article is to provide a review of the pathogenesis, current recommendations for the diagnosis and therapy of SIH. A report of a typical case should support our effort.
- Klíčová slova
- průsak mozkomíšního moku, epidurální krevní zátka,
- MeSH
- bolesti hlavy etiologie terapie MeSH
- intrakraniální hypotenze * diagnóza patofyziologie terapie MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic properties related to the rupture of cerebral aneurysms. Few of these studies deal specifically with aneurysm growth and most only use a single time instance within the aneurysm growth history. The present retrospective study investigated four patient-specific aneurysms, once at initial diagnosis and then at follow-up, to analyze hemodynamic and morphological changes. Aneurysm geometries were segmented via the medical image processing software Mimics. The geometries were meshed and a computational fluid dynamics (CFD) analysis was performed using ANSYS. Results showed that major geometry bulk growth occurred in areas of low wall shear stress (WSS). Wall shape remodeling near neck impingement regions occurred in areas with large gradients of WSS and oscillatory shear index. This study found that growth occurred in areas where low WSS was accompanied by high velocity gradients between the aneurysm wall and large swirling flow structures. A new finding was that all cases showed an increase in kinetic energy from the first time point to the second, and this change in kinetic energy seems correlated to the change in aneurysm volume.
- Publikační typ
- časopisecké články MeSH
The world currently faces the novel severe acute respiratory syndrome coronavirus 2 pandemic. Little is known about the effects of a pandemic on non-elective neurosurgical practices, which have continued under modified conditions to reduce the spread of COVID-19. This knowledge might be critical for the ongoing second coronavirus wave and potential restrictions on health care. We aimed to determine the incidence and 30-day mortality rate of various non-elective neurosurgical procedures during the COVID-19 pandemic. A retrospective, multi-centre observational cohort study among neurosurgical centres within Austria, the Czech Republic, and Switzerland was performed. Incidence of neurosurgical emergencies and related 30-day mortality rates were determined for a period reflecting the peak pandemic of the first wave in all participating countries (i.e. March 16th-April 15th, 2020), and compared to the same period in prior years (2017, 2018, and 2019). A total of 4,752 emergency neurosurgical cases were reviewed over a 4-year period. In 2020, during the COVID-19 pandemic, there was a general decline in the incidence of non-elective neurosurgical cases, which was driven by a reduced number of traumatic brain injuries, spine conditions, and chronic subdural hematomas. Thirty-day mortality did not significantly increase overall or for any of the conditions examined during the peak of the pandemic. The neurosurgical community in these three European countries observed a decrease in the incidence of some neurosurgical emergencies with 30-day mortality rates comparable to previous years (2017-2019). Lower incidence of neurosurgical cases is likely related to restrictions placed on mobility within countries, but may also involve delayed patient presentation.
- MeSH
- COVID-19 mortalita MeSH
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- neurochirurgické výkony mortalita trendy MeSH
- neurochirurgie metody MeSH
- novorozenec MeSH
- pandemie statistika a číselné údaje MeSH
- předškolní dítě MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- předškolní dítě MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- pozorovací studie MeSH
- Geografické názvy
- Evropa MeSH
Hemodynamické parametry hrají významnou roli ve vývoji intrakraniálních aneurysmat a jejich změny v průběhu dlouhodobého sledování mohou vést ke zvýšení rizika ruptury či k samotné ruptuře aneurysmat. Definování těchto změn by významně přispělo k pochopení vývoje a ruptury aneurysmatu. V této jedinečné práci jsou analyzována data čtyř incidentálních neprasklých intrakraniálních aneurysmat u čtyřech pacientů, kteří byli sledování v průměru po dobu 5 let až do chvíle ruptury aneurysmatu. Bylo provedeno matematické modelování hemodynamiky z dostupných dvou až tří angiografických vyšetření od každého pacienta, získaných během sledování, a změny hodnot hemodynamických parametrů byly analyzovány. Až na jedno, původně fusiformní, disekující aneurysma, velikost tří aneurysmat byla popsána na vyšetření MRA jako stacionární. Hodnoty minimálního smykového napětí se významně snížily a velikost oblasti s minimálním smykovým napětím ve vaku aneurysmat se významně zvýšily v průběhu času a výsledky naznačily podíl snižujících se hodnot smykového tření a rostoucí oblasti nízkého smykového napětí v průběhu času na zvyšování rizika ruptury aneurysmatu. K přesnému posouzení rizika ruptury aneurysmatu pomocí matematického modelování hemodynamiky, je nutné analyzovat více než dva modely aneurysmat a zaměřit se na signifikantní změny v hodnotách hemodynamických veličin.
Hemodynamic parameters play a significant role in the development of intracranial aneurysms and their time-depending changes during a prolonged follow-up period could lead to an increasing risk of rupture or to aneurysm rupture. The characteristics of these changes could bring significant information about the development of aneurysms and their rupture. In this unique study, we analyzed four incidental unruptured intracranial aneurysms in four patients who were followed-up for a mean period of 5 years until their rupture. We performed computational fluid dynamic simulations with the data from two or three follow-up angiographic examinations from each patient and analyzed the results with regard to time-dependent changes in terms of the values of hemodynamic parameters. Except one aneurysm of a fusiform dissecting origin, three aneurysms on MRA were described as non-growing. In the aneurysm domes, the minimal wall shear stress decreased and the low wall shear stress area increased significantly over time; the results indicated that the time-dependent changes such as decreasing values of minimal wall shear stress and increasing values of low wall shear stress area could lead to an increased risk of rupture. For accurate evaluation of the rupture risk using computational fluid dynamic simulation, it is important to analyze more than two models of aneurysm during a follow-up period and focus on significant changes in the values of hemodynamic parameters.
- Klíčová slova
- matematické modelování hemodynamiky, oblast nízkého smykového napětí, smykové napětí,
- MeSH
- aneurysma * patofyziologie MeSH
- hemodynamické monitorování metody MeSH
- klinická studie jako téma MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- teoretické modely MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- arteria cerebri anterior diagnostické zobrazování chirurgie MeSH
- CT angiografie metody MeSH
- dospělí MeSH
- intrakraniální aneurysma * diagnostické zobrazování chirurgie MeSH
- lidé MeSH
- mikrochirurgie metody MeSH
- neurochirurgické výkony metody MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
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.
Hemodynamic parameters play a significant role in the development of cerebral aneurysms. Parameters such as wall shear stress (WSS) or velocity could change in time and may contribute to aneurysm growth and rupture. However, the hemodynamic changes at the rupture location remain unclear because it is difficult to obtain data prior to rupture. We analyzed a case of a ruptured middle cerebral artery (MCA) aneurysm for which we acquired imaging data at three time points, including at rupture. A patient with an observed MCA aneurysm was admitted to the emergency department with clinical symptoms of a subarachnoid hemorrhage. During three-dimensional (3D) digital subtraction angiography (DSA), the aneurysm ruptured again. Imaging data from two visits before rupture and this 3D DSA images at the moment of rupture were acquired, and computational fluid dynamic (CFD) simulations were performed. Results were used to describe the time-dependent changes of the hemodynamic variables associated with rupture. Time-dependent hemodynamic changes at the rupture location were characterized by decreased WSS and flow velocity magnitude. The impingement jet in the dome changed its position in time and the impingement area at follow-up moved near the rupture location. The results suggest that the increased WSS on the dome and increased low wall shear stress area (LSA) and decreased WSS on the daughter bleb with slower flow and slow vortex may be associated with rupture. CFD performed during the follow-up period may be part of diagnostic tools used to determine the risk of aneurysm rupture.
- MeSH
- digitální subtrakční angiografie MeSH
- hemodynamika MeSH
- intrakraniální aneurysma komplikace diagnostické zobrazování patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- modely kardiovaskulární MeSH
- prasklé aneurysma komplikace diagnostické zobrazování patofyziologie MeSH
- subarachnoidální krvácení diagnostické zobrazování etiologie MeSH
- zobrazování trojrozměrné MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- přehledy MeSH
