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BackgroundUnderstanding 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.MethodsWe 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).ResultsWe 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.ConclusionOur 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.

Copyright of Česká a Slovenská Neurologie a Neurochirurgie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Copyright of Czech Radiology / Ceska Radiologie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Česká a Slovenská Neurologie a Neurochirurgie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Extravasation of blood in the central nervous system (CNS) represents a very strong damaged associated molecular patterns (DAMP) which is followed by rapid inflammation and can participate in worse outcome of patients. We analyzed cerebrospinal fluid (CSF) from 139 patients after the CNS hemorrhage. We compared 109 survivors (Glasgow Outcome Score (GOS) 5-3) and 30 patients with poor outcomes (GOS 2-1). Statistical evaluations were performed using the Wilcoxon signed-rank test and the Mann–Whitney U test. Almost the same numbers of erythrocytes in both subgroups appeared in days 0–3 (p = 0.927) and a significant increase in patients with GOS 2-1 in days 7–10 after the hemorrhage (p = 0.004) revealed persistence of extravascular blood in the CNS as an adverse factor. We assess 43.3% of patients with GOS 2-1 and only 27.5% of patients with GOS 5-3 with low values of the coefficient of energy balance (KEB < 15.0) in days 0–3 after the hemorrhage as a trend to immediate intensive inflammation in the CNS of patients with poor outcomes. We consider significantly higher concentration of total protein of patients with GOS 2-1 in days 0–3 after hemorrhage (p = 0.008) as the evidence of immediate simultaneously manifested intensive inflammation, swelling of the brain and elevation of intracranial pressure.

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.

Copyright of Česká a Slovenská Neurologie a Neurochirurgie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Treatment of complex aneurysms often requires additional surgical tools including the use of the extra-intracranial (EC-IC) bypass. The following report depicts the utilization of the EC-IC bypass in treating a dissecting aneurysm several hours after a salvage emergent evacuation of an acute subdural hematoma via decompressive craniectomy (DC). Preserving the superficial temporal artery during the DC provided a donor artery for the bypass surgery.

Brain ischemia after central nervous system (CNS) bleeding significantly influences the final outcome of patients. Catalytic activities of aspartate aminotransferase (AST) in the cerebrospinal fluid (CSF) to detect brain ischemia were determined in this study. The principal aim of our study was to compare the dynamics of AST in 1956 CSF samples collected from 215 patients within a 3-week period after CNS hemorrhage. We compared concentrations of the AST catalytic activities in the CSF of two patient groups: survivors (Glasgow Outcome Score (GOS) 5–3) and patients in a vegetative state or dead (GOS 2–1). All statistical evaluations were performed using mixed models and the F-test adjusted by Kenward and Roger and the Bonferroni adjustment for multiple tests. The significantly higher catalytic activities of AST in the CSF from patients with the GOS of 2–1 when compared to those who survived (GOS 5–3, p = 0.001) were found immediately after CNS haemorrhage. In the further course of time, the difference even increased (p < 0.001). This study confirmed the key association between early signs of brain damage evidenced as an elevated AST activity and the prediction of the final patient’s clinical outcome. The study showed that the level of AST in the CSF could be the relevant diagnostic biomarker of the presence and intensity of brain tissue damage.

Cerebral vasospasm and subsequent delayed ischemic neurological deficit is a typical sequela of acute subarachnoid hemorrhage after aneurysm rupture. The occurrence of vasospasms after uncomplicated surgery of an unruptured aneurysm without history of suspected rupture is extremely rare. The pathogenesis and severity of cerebral vasospasms is typically correlated with the amount of blood breakdown products extravasated during subarachnoid hemorrhage. In rare cases, where vasospasms occur after unruptured aneurysm surgery, the pathogenesis is most likely multifactorial and unclear. We present two cases of vasospasms following uncomplicated clipping of middle cerebral artery (MCA) aneurysms and a review of literature. Early diagnosis and therapy of this rare complication are necessary to achieve optimal clinical outcomes.

Intracranial pseudoaneurysms (PSA) are scarcely presented in the literature. We describe the case of an intracranial PSA on the right anterior cerebral artery, which developed during the complicated surgical treatment of a ruptured right middle cerebral aneurysm. The pseudoaneurysm grew over time and was co-incidentally diagnosed 3 months after the original surgery. The PSA was successfully treated by coiling. In cases of vascular injuries during complicated brain surgery, the timely and careful radiological diagnosis of such a lesion is necessary to allow its fast and proper treatment and thus prevent the patient from potential risks.

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. [ABSTRACT FROM AUTHOR]

Severe spontaneous subarachnoid hemorrhage (SAH) is predominantly caused by aneurysm rupture, with non-aneurysmal vascular lesions representing only a minority of possible causes. We present the case of a 58-year old lady with a coincidental posterior communicating artery (PCom) aneurysm and a high cervical spine arterio-venous fistula associated with a small ruptured aneurysm. After the emergency clipping of the PCom aneurysm, additional diagnostic procedures—repeated digital subtraction angiography and spinal magnetic resonance imaging, revealed the actual cause of the SAH, a type-A ventral intradural fistula at cervical level C2/3. The fistula was treated micro surgically via a ventral approach using C3 somatectomy and C2-4 stabilization after the initial failure of endovascular therapy. Furthermore, the patient was treated for complications associated with severe SAH, including acute hydrocephalus and meningitis. In cases where the SAH pattern and perioperative findings do not suggest an intracranial aneurysm as the source of SAH, further diagnostic investigation is warranted to discover the real cause. Patients with severe non-aneurysmal SAH require a similar algorithm in diagnosing the cause of the hemorrhage as well as complex conditions such as ruptured aneurysms.

Předkládaná kazuistika by měla ukázat a zdůraznit, proč je důležité vyšetřovat pacienty s mozkovou příhodou ve vertebrobazilárním povodí. Relativně novou a efektivní vyšetřovací metodou je kvantitativní MR (magnetickorezonanční) angiografie (QMRA). Tato metoda je schopna detekovat a neinvazivně měřit tok v a. bazilaris (BA) a obou zadních mozkových tepnách (PCA). Průtok pod 120 ml/min v BA a nižší než 40 ml/min v PCA (arteria cerebri posterior) definuje „low flow“ pacienty, kteří jsou indikováni k revaskularizačnímu zákroku (endovaskulárně stentem nebo mikrochirurgicky bypassem) [ABSTRACT FROM AUTHOR]

Copyright of Czech Radiology / Ceska Radiologie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim of the study: To present our rescue approach of carotid artery occlusion as well as to discuss other possible techniques that can be applied in similar situations.Materials and methods: Two cases from our institution with acute complications during carotid micro-endarterectomy (CEA).Results: Two cases from our institution with acute postoperative complications during CEA that were successfully addressed are presented with imaging and detailed description of the surgical techniques used.Conclusion: CEA are common surgical procedures pursued to achieve revascularization of carotid arteries when occluded partially or fully by an atherosclerotic plaque. As with any surgical procedure, associated complications exist in small percentage of the cases. These can include blood flow limitation due to an insufficient artery wall after atherosclerotic plaque extraction as well as distal kinking of the internal carotid artery. A direct end-to-end ACE-ACI bypass with occlusion of the proximal ACI and distal ACE stump preserves distal flow to the ACI, however the original arteriotomy of ACC must be completely sutured up to the arterial stumps. [ABSTRACT FROM AUTHOR]